Slow heating up during the start-up phase due to the insufficient heating capacity of the heat pump is one of the main causes of indoor thermal discomfort. Determining the most unfavorable start-up conditions for air conditioners is the critical to ensuring their rapid heating capacity and enhancing thermal comfort during the start-up phase. Given that, a numerical thermal model of typical urban residential buildings in Beijing and Nanjing is established in this study. Subsequently, the most unfavorable start-up conditions of heat pumps for bedrooms and living rooms under periodic heating conditions as well as long-term unheated conditions in two typical cites are analyzed. The results suggest that periodic heating has obvious alleviating effect on the most unfavorable indoor start-up condition compared with the long-term unheated condition.

The radial compliance design of scroll compressor can avoid the damage of liquid hammer or solid impurities through the concession of moving disc. However, too large compliance angle leads to excessive contact force between moving and stationary disc and intensified friction. Too small compliance angle leads to insufficient contact force between moving and stationary disc, contributing to leakage. To obtain a more appropriate radial compliance angle, CFD simulation is used to study the influence of radial compliance driving angle on the dynamic gas force and the contact force between the moving and stationary disc. The results show that the contact force between the moving and stationary disc decreases with the reduction of driving angle. Through the whole machine test at different angles, it is found that the input force under DOE-B condition decreases by about 1.0% when the driving angle is decreased by 10°. The efficiency is improved by about 1.0%, which verifies the effectiveness of the established CFD simulation method. The research can provide theoretical and practical guidance for the optimal design of radial compliance driving angle of scroll compressor.

With the extensive application of power supply, it is more and more important to research the efficientcy and reliability of power supply, as the power supply of O₃ sterilization device, required AC 4000 V voltaged, limited space, high efficiency, good stability. the traditional power convertor with the technology of LLC phase-shifting full-bridge, soft switching and so on can not get the requirements, in ordor to solve these problems, a new-type topology of power supply is proposed, two-stage boost and high frequency power supply. the working principle, parameter design and so on are analyzed detailed and researched importantly, the application of products are described in detail, and get ideal results, it provides a theoretical basis and a power promation model for practical application.

Taking blueberries, cherries, colored peppers, okra, fresh-cut apples and fresh-cut lotus roots as experimental objects, by measuring the Vitamin C content, anthocyanin content, total phenolic content, sensory score and total number of bacterial colonies, the quality changes of fruits and vegetables in the magnetic field fresh-keeping compartment and ordinary fresh-keeping compartment of the refrigerator were studied. The results showed that the loss of Vitamin C content in blueberries, cherries, bell peppers and okra was less in the magnetic field fresh-keeping compartment. The degradation of anthocyanin in blueberries and cherries was slower; the total phenolic content and sensory quality were decreased flatly, and the growth of the total number of colonies was inhibited. From the perspective of various indicators, the shelf life of fruits and vegetables under the condition of magnetic field refrigeration in the refrigerator was longer, and the preservation effect was significantly better than that of ordinary refrigeration.

With the advancement of technology and the improvement of manufacturing level, air conditioners have become a global product, and its mainstream trends include frequency conversion and energy saving. However, there are two urgent problems to be solved of the current inverter air conditioner. They are how to make the variable frequency drive control more generally adaptable to different power supply conditions, and improve the efficiency of the variable frequency drive. proposing an intelligent flexible boost control (IFBC) technology, which can effectively solve the following two problems: (1) the air conditioner can still work or not shut down when the voltage drops; (2) minimize energy loss and achieve the best drive control efficiency when the power generation constant K_e of inverter compressor is getting larger gradually. On the one hand, this IFBC technology can enable the air conditioner to start and run normally under the condition of low power supply voltage, ensuring the cooling and heating capacity. On the other hand, the boost control could be linked with the weak magnetic control which can be driven by a unified algorithm, to realize the optimization of this two control methods and achieve the best drive control efficiency with energy saving. The starting voltage can be as low as 120 V, the power consumption can be reduced by 8.6% at high frequencies above 65 Hz, and the average energy saving can reach 4%.

UG and Hypermesh software were used to build and mesh the air-conditioner outside unit model, and ABAQUS/Explicit software was used to simulate different kinds of the air-conditioner outside unit dropping process. The simulation results turned out that the left brace and the right rear board which need further strengthen were easy to become plastic deformed during dropping process. And the damage degrees of different dropping directions were compared in this paper.

In this study, chicken wings, eggplants and French fries were taken as the research objects to investigate the effects of three different cooking modes (Conventional Oven, Fan Forced and Intensive Bake) on food quality. The methods of texture analysis and sensory evaluation were used, treated with temperature test and cooking loss data during processing. The results show that the Conventional Oven mode (heat radiation) is the optimal cooking mode for chicken wings and eggplant, and the quality retention of chicken wings and eggplant cooked by this mode is higher than that cooked by other modes. Compared with the Fan Forced mode (thermal convection), the Conventional Oven mode improves the taste of the chicken wings by 6.51%; the Conventional Oven mode improves the taste of the eggplants by 6.79% compared with the Intensive Bake mode. The Fan Forced mode is the best cooking mode for roasted French fries, which improves the taste of the ingredients by 31.96% compared with the Conventional Oven mode. The inside heating rate is relatively slow when the Conventional Oven mode was used to bake fries, and the Intensive Bake mode has the fastest heating rate, while the rapid heating can bring the crispy taste of the fries.

Household soymilk machine have long been noisy, not fine crushing and other technical problems. Taking a new unmanned soymilk maker (note: unmanned soymilk machine refers to an automatic household soymilk maker that can clean itself) as an example. Through the use of TRIZ tools, analyzed the key cause of the noise that is related to the noise conduction structure of the crushing chamber. Combined with the actual situation, the project optimized the noise conduction structure of the machine and the ratio of the blade speed, reduced the peak noise of the machine from 79.9 dB to 68 dB, and reduced the particle size of soybean milk to less than 100 microns. The soymilk maker with low noise and the cell wall breaking technology improved user experience greatly.

The aerodynamic noise of the refrigerator fan has always been an important factor affecting the nominal value of the sound power level of the refrigerator. In order to ensure the braking and circulation efficiency, it is usually necessary to maintain a high rotating speed to obtain the ideal air volume, resulting in the increase of fan noise. The traditional noise reduction method is to reduce the rotating speed or reopen the mold to modify the aerodynamic effect of the blade. How to design the fan blade noise reduction on the premise of ensuring the air volume is the key. To solve this problem, a fan blade noise reduction method based on NSGA-Ⅱ genetic algorithm is proposed to constrain the air volume. By adjusting the blade installation angle and chord length along the radial distribution curve, the blades of a refrigerator axial flow fan are redesigned. The results show that the air volume of the new fan is the same as that of the original fan, and the wideband noise reduction of the pneumatic noise is realized in the range of 0~2000 Hz, and the largest decrease is in the range of 1050 Hz~1200 Hz. This provides a solution for the ultra-quiet design of refrigerator fan.

The dimensional deformation rate of foam is an important factor for affecting the deformation of the refrigerator door. Taking mold temperature, heat preservation and time as examples, the evaluation model for the influence of the multi-dimensional process parameters on the foam size deformation rate was studied. The model has the ability to qualitatively evaluate the eligibility and change trend of the dimensional deformation rate of polyurethane foam formed by various systems, and the reliability of the qualitative evaluation ability was verified.

The air inlet structure of 7-shaped range hood is located on the smoke collecting chamber, which is an important factor affecting the smoking effect. Based on the finite element simulation method, the fluid simulation analysis of different inlet structure schemes of 7-shaped range hood is carried out, and the influence of each structure on the smoking effect is explored. The simulation results show that the smoking effect is the best when there are openings in the upper and middle parts, and the smoking efficiency can reach 97.4% in theory. Only the upper structure with openings had the worst smoking effect, and the smoking efficiency was only 80.3%. And the experimental results are consistent with the simulation results.

The numerical simulation of the mixing process of atmospheric gas stove is established with the help of CFD simulation software. The reliability of the numerical simulation is verified by comparing the simulation results of the primary air coefficient with the experimental data. The mixing process of gas stove under different working conditions is simulated, and the influence law of hydrodynamic parameters (primary air coefficient, mixing uniformity and Reynolds number) on performance parameters (NO_x and CO emission) of gas stove under different working conditions is analyzed, showing that reducing the mixing heterogeneity can inhibit CO emission, and the other two parameters can promote CO emission. The overall law of all parameters and NO_x emission is opposite to that of CO emission, but the NO_x emission is the lowest at half open, which is due to the fast combustion speed and short contact time between reaction products and chemicals under this working condition.

By analyzing the research progress of meat products in low-temperature preservation in China and foreign, the concluded is that the optimal storage temperature of different meat products, and the control of the temperature variation range of different meat products storage, combined with additional preservation methods, are the development direction of low-temperature preservation of meat products. Provides high-value technical guidance on temperature control conditions during cold chain transportation and low temperature storage of meat products.

The current interactive mode of smart home can no longer meet the requirements of user interaction experience. Therefore, multi-modal senseless interaction methods and space remodeling construction are designed to create a whole-house senseless interaction and innovation application space, and improve users' intelligent experience in the home space is necessary. The system is constructed by designing multi-modal senseless interaction methods, including mood interaction, posture interaction, eye interaction, gesture interaction and emotional interaction, which are applied to whole-house active service scenarios, and through space remodeling, including office space remodeling, fitness space remodeling to solve limited space problems. Through the construction of the above system, it can provide users with non-inductive active services and break the fixed family space limitations, extending the family space indefinitely. The results show that the construction of multi-modal senseless interaction and space remodeling can provide important reference and design processes and methods for the whole-house intelligence era.

Aiming at the refrigeration air duct system of a refrigerator with two door double system and evaporator bottom installation structure, the three-dimensional volute model of logarithmic spiral line is created by using UG law curve method to quickly match the centrifugal fan. Then the numerical model creation and simulation research of the refrigeration room and refrigeration air duct system are carried out, which proves that the logarithmic spiral line volute has excellent aerodynamic performance, it can meet the stringent requirements of long-distance air supply of small air volume centrifugal fans. The performance of the whole machine is verified by experiments. The temperature fluctuation in and between drawers is within 1℃. The research results have certain reference value for the optimal design of the volute and air duct system of the refrigerator installed at the bottom of the evaporator.

With the development of VRF air conditioning systems, on the premise of ensuring quality, the market has higher and higher requirements for the cost of VRF air-conditioning products. At present, some small-capacity VRF in the market control the refrigeration system by temperature or the method of estimating pressure from saturation temperature, instead of high and low pressure pressure sensors. However, in the actual operation, the system inevitably has abnormal conditions such as vacuuming operation or refrigerant leakage operation caused by the hysteresis of temperature measurement. This paper analyzes the operating state, compares the operating parameters under different refrigerant leakage rate, and puts forward the abnormal control of refrigerant leakage with multi-parameter collaborative participation, which provides control ideas and experimental data for the research of refrigerant leakage.

The effect of blue light irradiation on quality of six common fruits and vegetables under 4℃ storage conditions were investigated, and non-blue light irradiation was treated as control. The results showed that with the blue light irradiation, the color and shape of fruits and vegetables was kept, the sensory scores of fruits and vegetables after storage for 7 days was improved, the formation of soluble solids during storage was delayed, the decreasing of vitamin C content of fruits and vegetables was delayed, and the growth of microorganisms on the surface of fruits and vegetables was inhibited. In summary, the blue light irradiation treatment could maintain the quality of fruits and vegetables, which is an effective method of preservation in refrigerator.

Compared with traditional microwave heating technology, RF oven using solid-state microwave heating technology which is heating fast and uniform, the status of food heating can be intelligent feedback, the size of core component power amplifier on electronics control board is small but with large power consumption, cause extremely high heat density. The traditional extruded heat sink cannot be effective under harsh ambient temperature 42℃ in summer. A high thermal conductivity graphite aluminum radiator is designed, which breaks through the technical drawbacks of conventional liquid preparation and solid preparation of high thermal conductivity composite materials. Using natural flake graphite and micron grade ultra-thin aluminum foil as the substrate, the unique multi-layer sandwich structure is formed by hot pressing at high temperature. The thermal conductivity of the two base planes can reach 600~1000 W/mK, which can reduce the temperature of the power amplifier chip by more than 8℃ compared with conventional aluminum extrusion radiator, this solution can ensure RF oven works safely under high temperature conditions.

With the diversity of external environments, it has brought serious challenges to the reliability of electronic products. In order for air-conditioning core devices-Printed Circuit Board Assembly (PCBA) from external environmental erosion, high reliability, household electrons widely use conformal coating to protect the integrated circuits and components of the circuit board, how to choose a suitable and process-fit conformal coating is a more complicated process. The researchers mainly introduced the composition and application principle of the conformal, and combined with the key parameters of the material, process characteristics and reliability test items that need to be paid attention to in practical applications, and verified by comparative tests, from anti-corrosion performance, electrical performance and process coating. In terms of coating, the conformal coating can be well selected and applied, which not only ensures the reliability of the material, but also meets the coating consistency and stability in the production process.

Common pump body fixing methods for rotary compressors include frame fixing, main bearing fixing and cylinder fixing. Among them, the cylinder fixing is relatively advantageous in terms of cost, but it is prone to deformation of the sliding vane groove after the welding of the lower casing in the assembly process. In order to solve the above problems, by establishing a thermo-solid coupling finite element simulation method, it is clear that the welding seam of the lower shell shrinks inward as a whole after cooling. The diameter of the cylinder (other parts except the welding point) is in contact, which destroys the original force mode of the cylinder and deteriorates the deformation of the cylinder vane groove. Simultaneously verified the reliability of the simulation model, and proposed an improvement plan for the outer diameter end face avoidance groove of the cylinder and the thickening of the lower shell, which significantly improved the deformation of the cylinder slide groove, reduced the defect rate of the production line, and ensured the smooth production of the production line.

Compressor built-in muffler has become a common compressor noise reduction structure, but how to design a good noise reduction effect muffler, is a direction of research. Through the muffler muffler principle, the common muffler structure characteristics in the market, such as different cavity type, outlet position, height, diameter, variable section, partition board and so on are analyzed; Based on the acoustic finite element method, the influence of each feature on the muffler's ability is clarified. On this basis, the above research results are applied to a compressor to solve the noise problem, which is used in the design optimization and comparative verification of the compressor built-in muffler. Finally, in solving the actual problem of the product, the good effect of focusing on the average noise reduction of 4 to 5 decibels in frequency band is realized. The research results have certain reference value for the noise reduction application of compressor and air conditioning system.

Aiming at the problem of large surface roughness brought by the secondary processing of the fins of the fins, use ANSYS software to establish a radiator-heat dissipation cream-power device micro-thermal conductivity model, analyze the heat transfer law, and use the roughness of the radiator to heat the heat dissipation. The impact of performance is studied to determine the appropriate surface roughness of the radiator to guide the processing and production of the wing-type radiator. According to the actual processing situation, the surface roughness Ra 3.2 μm and 6.3 μm were compared with the temperature rise of the machine. In the same case of the same working condition, the heat dissipation effect was not much different.

In modern life, indoor environment is the place where people have the longest contact time and the closest influence. To ensure the living environment health and comfort, people usually choose environmentally friendly indoor decoration, furniture, etc., or use air purifiers, humidifiers, range hoods and other electrical products to enhance the indoor air quality. Test chamber is a pivotal equipment for the evaluation and testing of building materials, interiors, air purifiers, air conditioners, range hoods and other products. It can well simulate the indoor environment during the test and provide a closed experimental space for testing the release or purification capacity of harmful substances of relevant products. Take a test chamber project from design and construction to final acceptance as an example, to introduce how the laboratory designs the specification, function and safety protection of the test chambers according to the actual requirements. Then carries out the acceptance of the test chamber through a series of processes such as calibration, safety confirmation and comparison test, until they could finally put into use. Aims to provide reference for industrial application.

The key points that affect the result of pressure cooking are temperature, pressure, power and cooking time, Improper condition control will lead to light taste,rich in oil and produce unpleasant odor, By summarizing the influence of electric pressure cooker stewing on the cooking effect and nutrients of the soup, In order to provide reference for the wide application of pressure technology in stewing and the development direction of electric pressure cooker stewing.

Because the combustion mode of the bias combustion gas water heater is more complex, the combustion stability is worse than that of the general atmospheric combustion water heater, which is prone to abnormal combustion noise. In order to study the specific reasons for the abnormal combustion noise of the bias combustion water heater, the structure optimization and design are targeted, and the abnormal combustion noise of the bias combustion gas water heater is experimentally studied and simulated. Through the experimental study, the influencing factors and the influencing rules of the abnormal combustion noise of the bias combustion water heater are obtained, the causes of the abnormal combustion noise are analyzed. On the basis of experimental research, the whole machine model is simulated and analyzed to compare the experimental results, which provides theoretical guidance for the subsequent design of the bias combustion water heater.

The main noise source of the water purifier is due to the pump, and the pump noise is transmitted through the air and structure. Because blocking air Transmission requires a high cost, the analysis of structural sound transmission has become the main means to effectively reduce the noise of water purifier. The pump in the water purifier is connected with the frame of the water purifier through screws, and the rubber pad is located between the frame and the pump. Therefore, the main structures that affect the structural sound transmission of the pump are the rubber pad and the frame. The experimental results show that the vibration isolation rate can be effectively improved by reasonable structural design and hardness selection of rubber pads and the noise of the whole machine can be reduced. In addition, pasting damping materials on the frame can effectively reduce the vibration amplitude of the frame and also block the transmission of structural noise.

Air-cooled refrigerator air duct structure characteristics directly affect the whole air volume and air volume distribution between rooms, which has a large impact on the performance of the refrigerator. CFD method is used to simulate the whole air duct system for a model of three-door variable temperature refrigerator. Through the analysis of the internal flow field, the air duct structure is optimized to eliminate the flow field vortex. The air outlet layout is adjusted to improve the air volume distribution between rooms. Finally, the whole air volume was improved from 14.8 g/s to 17.3 g/s, and the air volume of the variable temperature room was improved by 36%. Carrying out experimental verification, the refrigerator temperature distribution has been greatly improved, reliability test pass.

In the field of smart household appliances, voice interaction has become a major way of human-computer interaction. In recent years, with the development of technology, the voice interaction ability of smart household appliances has made great progress, but at present, the test of voice recognition ability is lack of targeted test of voice system for user instruction understanding ability. In order to solve this problem, this paper proposes a semi-automatic corpus generation method, and develops a corpus system for automatically generating test cases based on the generated corpus.

It is studied the energy-saving reconstruction of the existing household refrigerator performance laboratory, proposed the energy saving scheme, and compared the energy-saving accounting and the actual energy-saving benefit after the energy-saving reconstruction. We found that the energy-saving benefit can reach more than 20% from the energy-saving accounting or from the actual test comparison data after the energy-saving reconstruction. Through the economic analysis, the payback period for cost of the energy-saving reconstruction is about two years.

The function of the air conditioner is to adjust the air in the room to meet people's requirements for air temperature and humidity, so as to make the human body feel comfortable. However, because of different regions and climates, the functional requirements for air conditioners are also different. Taking the humid climate in the south as an example, excessive humidity can make the human body feel uncomfortable. Direct condensation and dehumidification will cause the air outlet temperature of the air conditioner to be low, which cannot meet people's requirements for temperature. Therefore, an air conditioner with reheating and dehumidification function is proposed here, and a brand air conditioner is used as an example to reheat and dehumidify it. The function is tested and verified to ensure that the air temperature of the air conditioner will not be lower than the user's requirement, and it can also increase the dehumidification capacity.

This paper takes a double fan ultra-thin wall embedded range hood as the research object, establishes CAE models for each of the four types of range hoods with different snail shell outlet widths, applies CFD methods to simulate the entire air duct, and conducts comparative analysis of air flow, velocity field and pressure field of the internal flow path. The air volume and noise of the above four types of range hoods were compared and verified through experimental tests. The fluctuation degree was used to evaluate the performance of the wheezing under 300 Pa back pressure. The results show that when the ratio γ between the width of the worm shell outlet and the opening degree is 1.25, the requirement of no surge under 300 Pa back pressure is satisfied, and the noise performance at the same air volume is better.

With the increasing volume of high-end refrigerator and the development of cryogenic technology, the size and working speed of centrifugal fan are increasing due to the demand of refrigeration performance, so the noise problem of large size fan become more and more prominent. The noise mechanism of the large size centrifugal fan and duct are investigated, through the simulation calculation and experimental testing, the critical factors in affecting noise are identified. By structure design of large size centrifugal fan duct, a balance between the performance and noise is achieved, which makes the performance meet the user requirements.

Hepa filter screen is usually used for fresh air purification in fresh air conditioning. In order to achieve no consumable purification, using conductive film as a dust collector to verify its effect on fresh air purification. Through the theoretical analysis of the charging process and adsorption process in the purification process, a simple numerical calculation model is established, and the samples under the existing structural dimensions are tested and analyzed. Through the test results and numerical model calculation, it is found that when the fresh air speed reaches 8.2 m/s, the thickness of the electronic filter element needs to reach more than 71.5 mm to have a better purification effect. Under the existing structure of fresh air conditioning, electrostatic precipitator technology is difficult to replace Hepa filter screen.

The compressor is the core component of the air conditioner, and its normal operation directly determines the use effect of the air conditioner. With the increase of the price of bulk raw materials and the increasingly fierce price war in the air conditioner market, the major air conditioner manufacturers are trying to apply various new technologies to the development of the air conditioner, so as to reduce the cost of the air conditioner, such as the application of aluminum tube heat exchanger, aluminum motor and small displacement compressor. Mainly study the application of miniaturized compressor in cabinet type air conditioning, and the abnormal attenuation of capacity occurs in the application process. In order to confirm the root cause of the problem, a number of visual mirrors in the system are added and relevant experimental test research are conducted. During the test, the state change phenomenon of refrigerant in different positions of the system in the experimental prototype is observed and recorded. Combined with the relevant experimental data, comprehensive analysis is carried out to find the root cause of the problem, so as to find the improvement or solution to the problem.

The effect of different forms of blade forward stacking on the performance of axial-flow fan is investigated by CFD method. Firstly, the blade forward stacking condition of an axial-flow fan is designed. Two forms of forward stacking blade, the forward overall-stacking blade and forward mid-stacking blade are proposed. Based on the numerical simulation method, the aerodynamic performance of these two forms of forward stacking blade and baseline blade is calculated and compared. The local Euler head (LEH) and blade loading in the flow field of impeller are extracted to reveal the mechanism of these effects of forward blade stacking on aerodynamic performance. The results show that, the blade forward mid-staking could improve the aerodynamic performance of axial-flow fan at the design flow rate and maintain that over the whole flow rate range. At the design flow rate, the blade forward mid-staking makes the blade loading at the impeller tip of axial-flow fan more concentrated in the front part, which is benefit to suppressing the tip leakage of impeller and improve the efficiency of fan.

In order to make the speech air conditioner not only support the recognition ability of a specific dialect, but also accurately and intelligently judge the dialect type used by users, the Attention-based Encoder-Decoder end-to-end system algorithm is preferred in the overall model architecture. Combined with SMAD technology, the end-to-end recognition system of cross dialect speech is built by using micro representation methods such as speech pronunciation characteristics and pronunciation positions, and the joint training method of dialect and wake-up words based on the conformer-transformer, which finally realizes the modeling of dialect recognition engine based on small data set, and realizes the functions of dialect wake-up and language adaptive judgment on the small resource system.

In order to further reduce the noise of range hood and improve user satisfaction. The mechanism of the aerodynamic noise of the range hood is systematically analyzed, and the targeted structural optimization and sound absorption and noise reduction design are carried out. Several technical schemes are verified by experimental tests. The test results show that the noise reduction is 0.6 dB(A) when the box height is increased from 400 mm to 500 mm under the nominal maximum air volume. Volute profile optimization, noise reduction 0.7 dB(A). Impeller eccentricity 135° noise reduction 0.2 dB(A). Optimized air outlet seat, noise reduction of 0.3 dB(A). The height of the box is increased by 80mm, and the noise reduction range is optimized. The perforated plate with a hole diameter of less than 4 mm, together with sound-absorbing materials, has a good sound-absorbing effect on medium and low frequencies, and the noise reduction of the sound-absorbing design is up to 4 dB(A). Through the optimization of the key air duct components of the fan platform and the sound absorption and noise reduction technology, the multi-dimensional coupling noise reduction of the whole machine is realized.

With the popularization and application of air conditioner, the comfort and energy saving of air-conditioning are the subjects that users are most concerned about. The principle of using millimeter wave radar to detect distance and angle was expoundes, and combines the application scenarios of air conditioning. The millimeter wave radar intelligently detects the distance, the left and right angles of the human body from the air conditioner, and the specific number of people. The air conditioner performs directional air supply control and runs the energy-saving mode.It not only ensures the user's comfort when using the air conditioner, but also achieves the energy-saving effect.

Taking the Patio air conditioning drainage pump as the research object, and analyzing the noise composition of the drainage pump. The idling noise and drainage noise are analyzed and improved from the source and transfer path analysis. The idling noise of the pump is effectively improved by changing the impeller and adding rubber rings. The drainage noise of the pump is improved by comparing the number of blades, blade height and blade edge opening. The research provide guidance for the subsequent low-noise design of Patio air conditioning pump.

The intermediate checks of laboratory equipment is an important means to ensure the effectiveness and reliability of equipment. Through the three examples of intermediate checks, focuses on the check methods for the accuracy, repeatability and stability of laboratory instruments and equipment, and draws the control charts corresponding to the accuracy check. According to the change trend of the check data in the control chart, find out anomalies and provide solutions.

The wall-mounted air conditioners are becoming more and more popular among consumers, the improvement of people requirements for a healthy indoor fresh air sound quality is increased. In order to ensure the indoor fresh air sound quality experience, fresh air module is taken as the research object. Under the condition of size limitation, the aerodynamic noise is improved by optimizing the design of the blade runner and centrifugal air duct; By optimizing the matching of the parameters of the external rotor motor with the fresh air load, the electromagnetic noise is improved and the competitiveness of the product is improved. The verification results show that aerodynamic noise and electromagnetic anomaly noise are effectively improved by reducing the noise value of the same speed by 2.5 dB(A) when the performance of fresh air volume is met.

With the improvement of national requirements for energy conservation and emission reduction, room air conditioner as a large consumer of household appliances, its energy conservation and efficiency has always been the top priority of the research of air conditioning manufacturers, but also the core demand of users. Vapor-bypassed technology can effectively solve the problem of increasing heat production while reducing pressure drop and improving system energy efficiency especially under low temperature heating conditions. The effects of vapor-bypassed evaporation technology on annual seasonal energy efficiency and the heating capacity of room air conditioners were studied by using gas bypass enhanced heat transfer technology, so as to provide reference for related technical fields. The experimental results show that the switch of the gas bypass system can promote the heat production of the system, the rated heat production is increased by 3.8%, the low temperature heat production is increased by 5.9%, and the energy efficiency of low temperature heating is increased by 4.2%. The annual energy efficiency consumption rate of air conditioners increased by 3.3%. At the same time, it is necessary to consider the effect of volume flow rate of bypass gas on capacity during system commissioning.

In recent years, consumers' demand for clothing washing and care is not limited to the traditional technology of cleaning. There is a growing demand for non-traditional clothing washing and care technologies with functions such as sterilization and deodorization. By analyzing the advantages of electro spraying, plasma, ultrasonic, free radicals, silver ions, rare earth catalyst, Micro Nano bubbles and other functional non-traditional technologies in the field of clothing washing and care application. And it is found that these technologies can effectively realize the sterilization of textiles, reduce unnecessary wear and tear, offer an eco-friendlier textile washing at the same time. The possibility of these technologies in washing, drying, ironing and other related application scenarios is prospected to provide a reference for the future development of washing and care technology.

The drum washing and drying machine has the functions of cleaning and drying clothes, the market demand for the drum washer-dryer is steadily increasing, and the demand for cost reduction also continues. Analyzing the needs and proposing a new topology of the drum washing and drying machine. According to the operating conditions, time-sharing multiplexed fans, in the washing and drying, the inductance characteristics of the stator winding of the fan are used to replace the grid-side reactor, which reduces the system cost. Then, combined with the topological structure of the dual inverter circuit, APFC is used to optimize the grid-side current, reduce grid-side harmonics, increase the amplitude of bus voltage, and increase the high-speed dehydration loading capacity of the motor. Finally, the simulation verifies the effectiveness of this scheme and provides new technical ideas for subsequent product development.

By analyzing the phenomenon of frosting and defrosting of evaporator, the scheme of shortening defrosting time of cryogenic vertical cabinet is verified. Using aluminum tube heating wire instead of steel tube heating wire for defrosting, Lengthening the size of steel tube heating wire and improving the power of defrosting heating wire, and program-controlled defrosting cut-off temperature, an effective way to shorten the defrosting time of household cryogenic refrigerators has been obtained. The main conclusions are as follows: the defrosting time is shortened by 5.5% when the aluminum tube heating wire replaces the steel tube heating wire; By lengthening the size of the heating wire, the defrosting time is reduced by 19.0%; The program controls the defrosting cut-off temperature, and the defrosting time is reduced by 24.1%.

Due to the wide range of cooling load of variable refrigerant volume, VRV system, the existing constant setting point of evaporation temperature control strategy always causes issues such as low performance efficiency and unsteady room temperature and humidity, especially with low part load ratio. A new kind of evaporation temperature control strategy of VRV system has been developed to improve the energy efficiency of the system and indoor climate control by setting variable evaporation temperature with predicted load. Thus, the key of the control strategy is to predict load on-line rapidly. Two kinds of data-driven models (Elman and along short-term memory neural network models, LSTM) have been developed to replacing the physical model, which is too complicated and time-consuming for VRV control module. The mean relative deviations of Elman and LSTM models are 8.6% and 2.0%. And LSTM model has been selected to couple with the control module due to its rapid computation speed and high precise. Furthermore, the effect of the load-prediction based variable evaporating temperature control strategy has been verified by the co-simulation of a VRV system model and a building model. According the simulation results, the VRV system applied the load-based variable evaporation temperature control strategy could consume less power than that of constant evaporation temperature control strategy under the low-load condition. And about 14% energy saving could be achieved by the new control strategy during the cooling operation period in Guangzhou, while the requirement of indoor thermal comfort has been satisfied. The load-based control strategy could be applied in remote intelligent cloud control system for VRV to reduce building energy consumption and carbon emission.

In order to solve the problems of large volume, short service life and high cost of electrolytic capacitor controller used for washing machine motor, the scheme of using non-electrolytic capacitor controller is proposed, but the problem of electromagnetic vibration of motor caused by non-electrolytic capacitor control is very large. Through the study of the influence mechanism of non-electrolytic capacitor on electromagnetic vibration, the generation mechanism of non-electrolytic capacitor electromagnetic vibration is quantitatively analyzed by electromagnetic simulation, which provides theoretical support and improvement ideas for the subsequent optimization design of non-electrolytic capacitor vibration. Based on the results of this study, the use of the stator laminations sample mechanism optimization combining with the current control scheme for sample and test verification, the results show that electromagnetic vibration improvement effect is obvious, fell by 50%~90%, vibration amplitude of the electromagnetic vibration to electrolytic capacitor motor vibration level, the result has played a very good damping effect, this study has guiding meaning for actual engineering application.

12 slot with 8 pole built-in permanent magnet BLDC motor as the research object, the key technology for rotor eccentric rotor, permanent magnet magnetic field intensity fluctuation manufacturing side of the impact of electromagnetic noise problem, based on finite element electromagnetic simulation, different computing process variation of the rotor in motor electromagnetic vibration and noise, finally qualitative quantitative analysis of the rotor effect and process of electromagnetic noise. The static eccentricity of rotor should be controlled within 10%, the dynamic eccentricity should be controlled within 10%, and the fluctuation of magnetic field intensity of permanent magnet should be controlled within 2%.

When the fan blows the air flow through the finned heat exchanger, it will produce a kind of broadband high-frequency noise. Starting from the CFD numerical simulation, studies the noise generated by the airflow through the heat exchanger. First, the CFD method is used to study the influence of different airflow sizes and air inlet directions on the vortex intensity in the fin gap, and then set the guide vanes according to the wind speed distribution on the heat exchanger to prevent high-speed airflow from directly blowing into the heat exchanger, which improves the abnormal noise problem.

Traditional integrated stoves generally have the pain points of low air volume, high noise, and shallow interior of the functional cabinet. Through the structural analysis of the traditional integrated stove, the root cause of the above pain points was found, and the technical solution for the horizontal fan was proposed. Through the comprehensive analysis of the usage scenarios and product performance, the horizontal fan structure was determined to solve the above problems. The simulation analysis and experimental study of the side-mounted fan of the traditional integrated stove and the innovative horizontal fan system show that the horizontal fan system can increase the air volume by 0.97 m³/min, reduce the noise by 0.7 dB(A), and improve the space utilization rate by 55.56%.

Through data collection and analysis of the user's cooking process of the temperature curve, analysis of the corresponding cooking behavior of the temperature curve characteristics, algorithm processing. Achieve not only can accurately judge the user fire and automatically open the smoke machine, but not only because of the interference of kitchen environment temperature change and wrong boot; Not only can accurately judge the user off the fire and automatic shutdown, and will not be in the small fire slow cooking process such as wrong shutdown; Not only can in the oil hot, pot explosion, add water, open the cover to view the larger scene of flue gas automatically increase the air volume, fast smoke exhaust net, achieve "net suction", but also in cooking and other smooth mode of flue gas scene, automatically reduce the air volume, reduce noise, achieve static suction; The overall cooking experience of users is greatly improved. There is no manual operation of the smoke machine during the whole cooking process, so as to satisfy the intelligent recognition of users' cooking behavior in the algorithm.

The problem of microplastic pollution has become a hot environmental topic of global concern. Microplastics released during the washing process of household washing machines are one of the main sources of microplastics in the environment. The effects of washing time, washing temperature and rotating speed of washing machine on the emission of microplastics in synthetic fiber clothing were studied, and the causes were analyzed based on the fabric mechanism. The results showed that washing time, temperature and rotation speed were positively correlated with microplastic emissions, that is, with the prolongation of time, temperature and rotation speed, the emission of microplastics increased. The order of significance of influence is: washing time > washing temperature > rotating speed. The causes include the characteristics of the microplastic shedding process, the swelling effect of fabric fibers, and the effect of mechanical force. Today, as the issue of microplastics is becoming more and more prominent, this study provides an important reference for the control of microplastic emissions from washing machines and subsequent research on collection and reduction.

Recently, air treatment system industry doesn’t have unified technical standard, typical reliability scientific theories do not effectively apply to product development, some companies do not consider the actual used environment and habits. Nevertheless, the reliability of air treatment system in design stage affects the maintenance cost of companies during warranty and the user experience during product life. Providing an accelerated reliability test method for air treatment system in design stage utilizing the experience of high reliability industry, Hallberg-Peck equation as well as the research results of actual users’ environment and habits. This method is verified by the comparison between the laboratory test data and the market data after the product launch, it can be promoted to the design stage of air treatment system industry.

Aiming at the problem that the frequency conversion refrigerator is qualified according to the national standard test, but the harmonic current test result may not be qualified according to the latest IEC electromagnetic compatibility standard test, puts forward a method of installing power factor correction circuit to the frequency conversion refrigerator to suppress the harmonic. Analyzes the difference between the national standard and the latest IEC electromagnetic compatibility standard on frequency conversion refrigerator harmonic current test, and verifies the feasibility of the scheme through the test data of frequency conversion refrigerator harmonic test. The experimental results show that the power factor correction circuit can reduce the harmonic current value, improve the power factor and suppress the harmonic effectively.

Compared with the indoor air enthalpy test method, using balanced ambient room-type calorimeter to test the performance of air conditioner has the advantages of small measurement error and high precision of test results. From the aspects of device development and design, calibration, test operation, by analyzing the key factors that affect the measurement results, such as the control of environmental working conditions, the installation of the tested machine and the measurement of the inlet and outlet water temperature, it provides reference for further improving the measurement level, reducing the experimental error and ensuring the consistency and accuracy of the results.

The built-in condenser used in household refrigerators has always been mainly circular tube type. In recent years, flat tube condenser has been preliminarily applied because of its good heat transfer characteristics. In order to study the performance difference between circular tube condenser and flat tube condenser, the heat transfer performance under different working conditions and foam thickness is studied by simulation analysis method. The results show that contrast to the circular tube, the average temperature of the outer steel plate is 0.2℃ higher, the outer heat flux of the steel plate can be increased by about 1.27%, and the overall heat exchange of condenser can be increased by 1.14% using flat tube under the same refrigerant temperature. The heat transfer effect of flat tube condenser is better than that of circular tube condenser.

The quality changes of abalone stored under freezing conditions at -18℃ and -60℃ for 56 days were investigated by determination of SAP loss rate, pH, TBA, myofibrillar protein content, carbonyl group content, total number of colonies, texture and sensory evaluation. The results showed that all indicators of abalone changed significantly with the extension of freeze-storage time. Lipid oxidation was delayed, myofibrillar protein degradation rate was reduced and microbial growth and reproduction was significantly inhibited under the condition of -60℃ freezing storage compared with -18℃. The original flavor and quality of abalone can be better maintained with lower temperature.

In order to study the influence regulation of the first and second throttle opening size impacting on vapor-injected system, the parking air conditioner R134a vapor-injected system was built. The parameters of the vaper-injected system was experimentally studied. The changing rule of the suction temperature, the discharge temperature, the temperature between inlet and outlet of the throttle valve with the first and the second throttle opening size was obtained by analysing of experimental data, which would provide theoretical guidance to vapor-injected system design.

The wind deflector of indoor unit of split-type air conditioner was selected as the research object, and the CFD software was used to numerically simulate the wind deflector in three kinds of cross-sectional shape. The flow field inside the indoor unit of air conditioner was acquired, and the influence of the flow field at the outside by wind deflector with difference section was analyzed. The theoretical basis was provided for the optimization design of the wind deflector. The performance of air volume, noise and condensation of the indoor unit of air conditioning at low revolution speed and the 55° opened angle was better by use the wind deflector with airfoil section through experimental verification.

Based on the traditional TM direct cooling refrigerator, fans are respectively equipped in the refrigeration to improve the speed reduction effect of the direct cooling refrigerator and solve the uneven temperature distribution in the direct cooling refrigerator room, so as to meet the user's requirements. Taking the Pakistani market as the starting point, combined with local climate types, religious culture and eating habits, deeply analyzes the pain points in the use of users' refrigerators, and excavates the needs of local users for large storage space. Based on the function of traditional direct cooling refrigerator, a large volume TM direct cooling refrigerator with fan (nearly 500 L) is innovatively designed by using the method of simulation and experimental research, which not only meets the pursuit of large volume by local users, but also solves the difficulties of slow speed reduction and uneven temperature distribution caused by large volume.

In order to quickly obtain high-precision full performance curve of refrigerator compressor under as few test conditions as possible, a new calculation and correction method of full performance curve is proposed. Firstly, the cooling capacity, inlet force and unit flow of a refrigerant under different working conditions are obtained by looking up the table with thermodynamic software. Secondly, according to the ten coefficient method, the ten coefficients of each performance of the compressor are obtained, and the theoretical full performance curve is drawn. Finally, through the experimental test of three operating points, the theoretical full performance curve is modified to obtain the real full performance curve. The experimental results show that the error of this method is small. Therefore, compared with the traditional method, the new method can obtain the full performance curve of the compressor simply, quickly and accurately.

In order to solve the problem of the uniformity of the air circulation, improve the temperature uniformity in the box, and reduce the condensation of the glass door, studies and analyzes the air duct structure based on the horizontal glass door air-cooled display cabinet. An air supply scheme is designed that adopts the basic airflow organization form of air outlet from the upper part of both sides and return air from the lower right side. The air duct structure was optimized by Fluent, and the influence of parameters such as the arrangement of the air outlet and the outlet angle of the air outlet on the temperature uniformity in the box was studied and analyzed. An air supply scheme is obtained that satisfies the temperature uniformity in the box not to exceed 2°C and the proportion of condensation area of the glass door not higher than 5%.

As more and more new buildings are mainly high-rise buildings, in order to protect the life safety of air-conditioning installers and prevent outdoor units from falling off during the use of the air conditioners, more and more outdoor units are installed in blinds style which is hidden way. But blinds will block the air out of the outdoor unit, causing poor air flow and exhaust air backflow to the outdoor unit, and the actual temperature in the blind space where the outdoor unit is located is higher than the external environment temperature, this will adversely affect the performance, energy efficiency and reliability of the air conditioner. The purpose is to summarize the design process of the air duct structure of the air supply system in the development process of an air-conditioner product's outdoor unit, comparing the influences on the air supply wind field of the whole machine with different air duct heights and air duct R angles, to get the optimal value of the height of the air duct by fitting the test data, and making the actual comparison test of air supply wind field in both two situations which before and after the improvement, the machines with two different air-duct heights simulate the overall performance in the blinds installation environment with different operating frequencies. It has been verified that the heat reflow rate of the whole machine is reduced by more than 50% after the improvement, which can significantly improve the performance and reliability of the whole machine in the blinds installation environment.

The air conditioner has higher requirements for the speed of compressor.Flux weaking control is an important strategy to improve the running speed of compressor.On the basis of FOC vector control adopted by the compressor,analy the control model of the compressor, the negative i_d compensation is obtained by analyzing the control model of the compressor.Then the flux weaking control model of negative i_d compensation method is established. The model adjusts the output voltage and the target voltage to obtain the flux weak compensation, and adds a low pass filter module and an anti disturbance clamping module in the flux weak control loop to reduce the disturbance of flux weak output in the steady state and improve the control stability. Finally, the algorithm is applied to variable-frequency air conditioning, and the experimental results show that the negative i_d compensation flux weak scheme can improve the compressor speed, and the flux weak compensation is not disturbed in the steady state.

From the analysis of the principle of the heat exchange capacity of the outdoor unit of the air conditioner, the outdoor side air volume, and the calculation method of the heat exchange of the condenser, by optimizing the design of the external size of the outdoor unit, the key parameters of the fan and the heat exchanger, the height of the outdoor unit is reduced, and the width and thickness are increased. Reduce the height of the heat exchanger, increase the number of rows, and optimized and upgraded the dual-fan outdoor unit to a single-fan type. The experimental method compares the two outdoor units in terms of air volume, wind field, noise, performance of the whole machine, material cost per unit, and packing volume: it is concluded that the air volume, noise, and performance of the two outdoor units are the same, and the wind field of the single-fan outdoor unit is more uniform, the material cost of a single unit is reduced by 260 yuan, and packing quantity is increased by 20%.

The energy efficiency requirements of market products are becoming more and more standardized and upgraded year by year. Dehumidifier products are also facing the same problem. On the one hand, they are facing the requirements of the miniaturization of the fuselage, on the other hand, they are facing the demand of greatly improving the energy efficiency coefficient. Therefore, it is proposed to study and improve the heat exchange effect and optimization strategy of the condenser of the dehumidifier to meet the market demand and customer requirements.

The refrigerant of the air conditioner boils and exchanges heat in the copper tube, and the heat is transferred to the copper tube wall, and then the heat is transferred to the fins through the tube wall. The fins then conduct convective heat transfer with the air to transfer the heat to the designated space. The fin side heat transfer efficiency is lower than the boiling heat transfer efficiency in the tube, and the heat transfer bottleneck is on the fin side. By optimizing the layout of the copper tubes and heat exchange fins of the evaporator and condenser, increasing the width of the fins, reducing the fin spacing, adjusting the refrigerant flow path pertinently, improving the circulating air volume and wind speed, and maximizing the heat exchange efficiency at the fin side, so that the heat or cooling capacity in the copper tubes can be fully transferred to the air side through the fins, to get better performance and cost of the whole machine.

Sleep accounts for about 1/3 of users' life time, which is an important scene of smart appliances. In order to get sleep, some smart air conditioners will adopt linkage bracelets, smart pillows and other methods, which require users to wear or buy additional linkage products. In order to collect the sleep state with low cost, no feeling and more accuracy, a method of obtaining the user's sleep state through a miniaturized remote controller is introduced. The acceleration sensor is placed on the miniaturized remote controller, which is clamped on the user's pillow to collect acceleration data to realize the recognition of sleep and the judgment of sleep quality. There is no need to wear and the cost is low. The effective acceleration data filtering algorithm and sleep entry/exit recognition method are studied. The sleep quality judgment method is extracted based on Pittsburgh sleep quality index, and the corresponding air-conditioning sleep scene application is designed.

With the development of household air conditioning, for some special scenarios, such as the base station room, Internet cafe, wine cellar, kitchen, etc., the indoor temperature is high and the outdoor side temperature is low, so it needs to have a low-temperature refrigeration function. Under the working conditions of 21℃ and 32℃ on the inner side, test and verify the working conditions of 12℃, 4℃, -2℃, -10℃ and -15℃ on the outer side respectively, and analyze the oil return and liquid return in combination with the phenomenon of the liquid sight glass of the compressor. It is confirmed that the liquid storage tank of the compressor needs to be able to accommodate more than 65% of the refrigerant mass. For refrigeration under the low-temperature working conditions on the outer side, it is necessary to ensure that the superheat at the bottom of the compressor is above 5℃,for the high-temperature working conditions, it is necessary to pay attention to whether the pressure will exceed the standard. By adjusting the frequency of the compressor, the speed of the external fan and the opening of the expansion valve, the superheat can be increased and the pressure can be reduced to avoid liquid return.

As the "double carbon" target is getting higher and closer, as a major energy consumer, the energy-saving requirements of household air conditioners are also constantly improving, and energy-efficient household air conditioners have been increasingly required to be widely used. At present, the main energy-efficient air conditioners in the domestic market are frequency conversion products, and the energy-efficient goal is relatively easy to achieve, but there is still a large demand for fixed frequency air conditioners in the overseas market in the short term, especially in the Middle East, Thailand and Israel. Mainly analyzes the influence of the key indexes of the air conditioner, such as the refrigerant charge, the design of the two air conditioners, the fan motor speed, the compressor displacement, on the air conditioning refrigeration system in this kind of energy-efficient air conditioner system. The influence of more or less refrigerant charge on the compressor and refrigeration system is analyzed, and the judgment method of whether the refrigerant charge is appropriate is put forward. The corresponding relationship between the displacement of compressor and the volume ratio of indoor and outdoor heat exchanger is analyzed, and the matters needing attention in the selection of high energy efficiency air conditioning system are summarized.

With the popularity of air-conditioning products, people have higher and higher requirements for the comfort of air-conditioning products, among which air-conditioning condensation has become one of the problems that people focus on and need to solve. The influence of different parameters on condensation is analyzed through the experimental study of the variable frequency wall-mounted machine under different humidity, different wind swing angles and different compressor frequencies. The results show that the frequency converter can effectively solve the condensation problem by reducing the compressor frequency under low humidity, and the angle of the air plate not only affects the temperature of the outlet air, but also affects the flow field characteristics of the outlet, thereby affecting the generation of condensation. In a high humidity environment, it is necessary to comprehensively adjust various parameters to achieve the optimal anti-condensation effect.

The unopened stop valve of the air conditioner has a great impact on the reliability and safety of the equipment. In order to study the influence law of the unopened stop valve on the air conditioner and summarize the automatic detection method, an experimental study was carried out on the unopened stop valve. Through experimental research, the change rules of system parameters under different operation modes and the combination of four stop valve switching states is obtained. Based on this, an automatic detection method of unopened stop valve is proposed. Under the condition that the system hardware configuration remains unchanged, the unopened state of the stop valve can be determined by detecting the system state parameters. The results show that this method can effectively and accurately identify the unopened state of the stop valve, and significantly improve the reliability and safety of the system.

With the widespread use of air conditioning, the competitiveness of air conditioning enterprises is also increasing. In order to occupy a certain share in the market, it is necessary to pay attention to the creation of brand and product characteristics. As a key component of the outdoor unit of the air conditioner, the grille has a great impact on the performance of the whole machine. If the air conditioning capacity is poor or the noise is too high, the customer satisfaction will be reduced. In this paper, the reliability of the grid structure will be analyzed through wind field simulation, and then the air volume test will be carried out to verify the impact of the grid on the air volume, and the grid will be preliminarily optimized. Finally, the wind field characteristics of the windmill type grid are better, and the capacity has also been significantly improved.

In order to improve the sound quality experience of fresh air, the fresh air module is taken as the research object, through the noise source identification and modal analysis methods, reinforcement ribs are set up on the non-contact surface of the cavity and a shunt cone is set in the cavity, so as to optimize the mode of the air cavity and the internal air flow organization, and improve the low-frequency radiated noise caused by the high-speed inflow impact. The verification results show that at the same speed, the fresh air volume is increased by 3 m³/h, avoiding the excitation frequency and the excitation peak value is reduced by more than 15 dB(A), which effectively improves the cavity sound of the fresh air module and improves the experience of indoor sound quality.

In order to solve the urgent need for air conditioners in some schools, and the difficulty of purchasing air conditioners in large quantities due to the shortage of funds and the difficulty of line transformation, Our company designed and developed a shared air conditioner. sharing air conditioners can save the school from having to spend a lot of money to buy air conditioners. Our company will provide air conditioners for free, including the wiring transformation and installation in the early stage and the operation and maintenance in the later stage. The school only needs to pay for the use according to the actual situation. The shared air conditioning system uses NB-IoT communication module. Relying on the narrowband Internet of Things of Telecom, the communication data is uploaded to the telecom cloud, and the WeChat small program is connected to the cloud platform to display and control the status of the air conditioning, so as to realize the sharing operation of the air conditioning, such as scanning code lease, surrender lease and centralized control.

With the promotion of the carbon peak and neutrality strategy, air conditioner energy saving is becoming more and more important. So a household air conditioner energy saving method based on regression analysis is proposed. Establish a model between the compressor running time and indoor temperature difference, and solve its coefficients through regression algorithm, the temperature difference can be calculated and the compressor frequency can be adjusted in advance, so the energy waste caused by excessive dehumidification and temperature adjustment can be avoided. The experiment results show that this method can save energy up to 10% which can be used widely.

Generally, the temperature and humidity of refrigerators change greatly with startup and shutdown. For better products, the temperature change range at different places at different times can be controlled to about 3℃, and the humidity change range will be larger. Some products reach a relative humidity below 50% when the compressor is running, but it may reach about 90% at shutdown. For products with special storage requirements, it cannot meet the needs. In order to achieve the storage effect of such items, water is used as the refrigerant to let the refrigerant pass through the heat exchanger. The temperature of the heat exchanger is near the dew point temperature, and PID technology is used to accurately control the speed of the compressor, the speed of the cooling fan, the temperature of the refrigerant, etc., so as to achieve accurate control of temperature and humidity.

Short circuit failure of electric control board of outdoor unit caused by mosquitoes accounts for a high proportion of electric control board faults, which seriously affects user use and safety. Through the research and analysis of the failure mechanism of mosquito electric control board, and according to different ways of placing electric control board, the protection measures of electric control board and structure are given, which provide ideas and guidance for the subsequent design of outdoor machine mosquito control.

There is exhaust pulsation in reciprocating refrigerator compressor. Reducing the exhaust pulsation of reciprocating refrigerator compressor can effectively improve the matching noise in corresponding frequency band of refrigerator. Summarizing and analyzing the research theory and present situation of reciprocating refrigerator compressor, including pipeline throttling technology, buffer cavity structure and volume isolation technology. Discussing the future research direction of exhaust pulsation of miniaturized reciprocating refrigerator compressor.

The temperature and humidity control of wine cabinet is the most concerned technical parameter of users. At present, the temperature control has reached the level required by users, but the humidity control has a wide range of fluctuations. Therefore, it is necessary to study the humidity control methods that can be used in wine cabinets. Humidity control methods include humidification methods and dehumidification methods. Anhydrous humidification, isoenthalpy ultrasonic humidification and wet film humidification can be used for wine cabinet humidification, and condensation dehumidification, absorption adsorption dehumidification methods can be used for wine cabinet dehumidification.

Refrigerant charge has an important influence on the performance of the refrigeration system. In order to determine the optimal charging volume of display cabinet refrigeration system and the influence of charging volume and air volume on system performance, a series of experimental studies were carried out using R290 refrigerant in a type of vertical glass door refrigerator with different charging volume, flow rate and air volume. This study can provide theoretical guidance for the optimal filling volume, flow rate and air volume matching of vertical glass door refrigerator refrigeration system.

Reducing the DC bus capacitor of variable frequency controller is an effective means for cost reduction and increasing power density, which is also of great significance for low carbon, environmental protection, energy saving and emission reduction. Currently, many air conditioning companies are trying to reduce the DC bus capacitor. However, this would enlarge DC bus voltage fluctuation, which further deteriorates the life and reliability of system. To solve this problem, deeply analyzing the mechanism of DC bus voltage fluctuation for air conditioner’s variable frequency controller. Based on the energy change of both input side’s PFC and output side’s compressor, and the principle of instantaneous energy balance, the mechanism of DC bus voltage fluctuation is proposed, which provides effective theoretical basis for research and realization of DC bus voltage fluctuation reduction.

The developed countries in European economy countries have focused on promoting energy consumption and carbon dioxide emissions reduction since 2018. The technical model analysis of solar thermal utilization in Europe is intended to provide reference for rural solar cascade thermal utilization in China. By analyzing the low-carbon energy supply pattern in these countries, it is found that the residential structure represented by small villages in Europe is different from large urban agglomerations in China. In the energy field, it is highlighted by the rapid development of decentralized low-carbon buildings combined with heating and heating in winter. In addition, through the analysis of solar thermal application in Europe, it is believed that the key prerequisite for promotion of solar thermal utilization is to reduce the cost of solar heating elements and improve the efficiency to increase secondary profits. Solar thermal utilization is the most economical and reliable way in the long run.

In order to study the influence of fin type on the cooling and heating performance of the whole machine and the defrosting of low-temperature environment, three kinds of fin type condensers were tested. The results show that the heat transfer effect of the bridge type heat exchanger is the best and that of the flat type heat exchanger is the worst under the same system configuration under the refrigeration and high-temperature heating conditions without frost; Under the low-temperature heating condition (unstable operation and frosting condition), the corrugated plate heat exchanger has the best heat exchange effect, the bridge plate heat exchanger has the worst heat exchange effect, and the frost formation of the bridge plate heat exchanger is the most serious. When designing a heat exchanger, the fin type should be selected based on its heat exchange efficiency and use scenarios.

Aiming at the noise reduction requirements of outdoor units of air conditioners, a design of acoustic enclosure by combining theoretical calculation and FEA is adopted. Firstly, according to the structural characteristics of the outdoor unit of the air conditioner, the frame structure of the acoustic enclosure is designed. On this basis, considering the air duct noise and pore leakage, according to the target noise reduction and spectral characteristics, the size of the acoustic enclosure is adjusted, and the sound insulation is checked by the FEA method. The sound pressure level of the final physical test is reduced by 3~4 dB(A). The design method has certain reference significance for solving similar engineering problems.

Suction muffler is an important component of compressor. It’s structural design affects both the cooling capacity, COP and the noise of compressor. By establishing the compression simulation model, this paper can directly calculate the performance parameters of the compressor, such as cooling capacity, power, cop, volume coefficient and so on. Combined with the acoustic cavity transmission loss simulation model, the performance and noise of suction muffler can be optimized synchronously. This method is used to optimize the design of base muffler of a variable speed compressor, and two improved models are proposed. The measured results show that the cooling capacity 72 Hz of the variable speed compressor is increased by about 5%~7%, and the noise is equivalent to that of base. The simulation results are consistent with the measured results.

Based on the noise problem of the air conditioner, the authors research the resonance problem of fan motor and pipeline blower, analyze the drawback of the present harmonic injection based noise suppression technology. Based on this, the authors proposed the adaptive noise suppression method. In the proposed method, a feedback loop is constructed from an acceleration sensor and realize the condition monitor of the system vibration resonance. The injected harmonics are automatically adjusted according to the vibration, and the best suppression is realized. The resonance noise is resolved by the proposed method.

During the noise test evaluation of a DD Motor for drum type washing machines, a high order rotation frequency noise problem caused by rotor was found. The noise is represented by a high peak near frequency of rotation times the number of stator slots and the interval is about the rotation frequency. Through theoretical analysis and test verification, it is found that the noise problem is mainly related to the shape of inner circle of rotor. In order to quantify the shape characteristics of the inner circle of the rotor, a method to measure the shape of the inner circle of the rotor of DD motor is presented, which can measure the complete shape profile of the rotor. Through theoretical and experimental research, the key technology points of DD motor noise control are defined, which is conducive to the improvement of product competitiveness. Meanwhile, the research results are applicable to all kinds of external rotor brushless DC motors.

To study the influence of geometry parameters to mode performance and mass of pipes, taking a section of pipeline of an outdoor unit as research object and creating geometry parameters of the shape of pipes, according to response surface DOE analysis and sensitivity analysis, the influence of geometric parameters to modal performance and mass are studied in order to find which parameters have high efficiency to optimize its modal frequency, at last, the effectiveness of this method was proved by test of whole system.

Based on Lighthill's acoustic analogy theory, the noise of range hood is analyzed, the main noise source of range hood is determined, and the modification and optimization are carried out according to the important influencing factors of noise κ-ω The numerical simulation analysis of the flow field of the turbulence model is carried out to verify the flow performance before and after the modification, and the scheme of noise reduction is effective, which provides a valuable direction for future research.

The main reason for the large difference of the left and right outflow commutation performance, the small air volume and the high noise of the existing integrated stoves is the direction of the outflow of the air cabinet, which changes from vertical outflow to horizontal outflow, causing a large energy loss. The second reason is that the upper end of the air cabinet is close to the air inlet, and the front and back side of the air wheel are insufficient. Optimizing the layout of the air duct as a straight-row type, avoiding the loss of air outlet reversal, and at the same time, optimizes the vertical and axial positions of the cabinet. Through the experimental tests, the noise is reduced by 6.7 dB(A) under the same air volume.

By analyzing the problem of the ripping sound of drum washing machine at 1120 r/min, through mechanism research, its essence is a beat vibration phenomenon. On the basis of mechanism research, according to the characteristics of noise performance, analysis of excitation source, the belt pulley produced by the third harmonic excitation and motor bearing damage caused by 3.1 times of frequency excitation force interaction is the main cause of the problem. The problem was diagnosed and controlled from the optimization of belt structure and roundness of inner and outer raceway of bearing, the test results showed that the problem of the ripping sound was effectively improved. The accuracy of mechanism analysis is verified and theoretical guidance is provided for solving the ripping sound of drum washing machine completely.

The premise of vibration and noise reduction in refrigerators is the accurate identification, separation and quantification of noise sources. According to the noise source and transmission path of refrigerator products, the noise source identification technology based on partial coherence method is applied to identify the noise source. Aiming at the noise problem of a refrigerator, a multi-input single-output system model is constructed, and the noise sources with larger contributions are identified by analyzing the partial coherence coefficient between the noise sources. By reducing the noise of the main noise source, the noise reduction of the refrigerator is realized.

Air conditioners installed on different buildings will show different noise problems. The operating frequency of the air conditioner, the vibration of the air conditioner, and the building resonance frequency have a greater impact on the low-frequency noise. In order to study its influence on low-frequency noise, install air conditioners in semi-anechoic rooms and design to simulate the phenomenon of low frequency sound generated by building structures, experimental research was carried out on it. Experimental study shows the influence of specific operating frequency of air conditioner on low-frequency noise of buildings. Aiming at the low frequency noise of buildings caused by the air conditioner, it is effectively solved by vibration isolation.

Multi-motor networking integrated control is a problem often encountered in the design of modern modular motor systems. How to achieve reliable and simple synchronous operation of multiple motors is a problem that must be considered. By expounding a set of motion control system that uses the embedded chip STM32F103 combined with the motor-specific driver chip, uses the Modbus RTU protocol for network communication to transmit data and commands, uses this communication mechanism to develop the motor controller, and builds a set of motion control systems that work together with multiple drives. Using this system, the master station can control multiple motors at the same time, and the control system is compatible with the traditional industrial controller interface RS485.

The problem of corrosion and leakage of the heat exchanger of the parking air conditioner is serious. The reasons for the corrosion and leakage of the heat exchanger are studied by means of microscopic observation and component detection, and the corrosion resistance of the heat exchanger after anti-corrosion treatment is studied. The research shows that the leakage of the heat exchanger is caused by the pitting and perforation caused by Cl^- and S^2-. The heat exchanger was immersed in water-based resin coating, and then treated by air drying and high temperature curing. The corrosion of the heat exchanger after anticorrosion and anticorrosion treatment was compared by neutral salt spray test and SWAAT test. The experimental results show that the corrosion resistance of heat exchanger coated with water-based resin coating is significantly improved, which provides effective ideas for the design of anti-corrosion process of heat exchanger products.

The top cover of the outdoor unit of the air conditioner is a sheet metal part with a large area and a thin material thickness, so its structural rigidity is weak, and it is often faced with harsh conditions such as falling and stepping during transportation and installation, and the parts are easily deformed and cause customer complaints. Therefore, it is of great significance to effectively improve the structural rigidity of the roof. Adding stiffeners to the roof is an effective way to improve the stiffness. The structural parameters of the roof stiffeners will be studied, and the ANSYS simulation software will be used to study the influence of the stiffener width, clearance, height and other parameters on the roof stiffness. The results show that the stiffness of the roof can be effectively improved by the stiffeners reasonably, and the height of the stiffeners has the most obvious effect on the stiffness optimization of the roof under the premise of meeting the sheet metal process. An effective optimization method is proposed to improve the rigidity of the roof. It provides important directional guidance on how to improve the rigidity of the roof.

SMT (surface mount technology) is the most popular technology and process in the electronic assembly industry, and solder paste is the key auxiliary material in the surface mount technology, and the cold welding phenomenon often appears in the welding process is also related to solder paste. Through the analysis of solder paste material, confirmation of application parameters (solder reflow curve), microscopic observation of solder paste on chip pin pad and comparative analysis of solder paste on PCB with different surface treatment, the aim is to find out the root cause of "cold soldering" phenomenon in SMT welding process, and adjust the application process conditions, avoid welding defects and ensure the reliability of electronic products.

Because the single panel only has copper foil pad on one side of PCB, it is difficult for tin wave to form good wetting and tin on the pins of plug-in devices during wave soldering, so there are often through-hole defects after welding. Comprehensively analyzes the through-hole defects of single panel, compares and follows up the improvement of PCB plate resin structure, punching process, different punching times, different plates and different processing manufacturers, and checks and confirms the parameter settings of wave soldering wire body. The results show that PCB substrate is the main cause of through-hole confirmation. By adjusting the resin structure of PCB plate, the zigzag strength of PCB plate can be changed, so as to improve the phenomenon of copper skin warping and burr in the hole during PCB hole processing, and then reduce the generation of through-hole defects.

In order to improve the pulping performance of the soymilk machine, it is usually necessary to concentrate the crushing of the materials through the mesh cover, causing cleaning to become a major pain point for users. In order to improve the user experience of the soymilk maker and realize the automatic cleaning function of the soymilk maker, a minimum three-stage crushing cavity is designed. There are three different slopes at the water climbing part of the soymilk maker cavity to reduce the process energy loss. Through the analysis of fluid mechanics and experimental verification, it is found that the designed three-stage cavity structure makes it more conducive to the recycling of materials when crushing soybeans and improves the crushing performance; it is beneficial to water climbing during cleaning and easier to clean to the cup. Cover, good cleaning effect.

Motor is a key part of the compressor which can transfer electric energy to compression energy of gas. The high pressure of refrigerant compressed by compressor pushes the refrigerant to circulate in the system. The energy efficiency of compressor is determined by the motor efficiency. Different characteristics of the designed SPM synchronous permanent magnet motor combined with the load characteristics are described. There are many advantages for light commercial compressor using SPM synchronous permanent magnet motor. The test results indicated that light commercial compressor with SPM synchronous permanent magnet motor has better running performance under different working conditions.

The keys on household appliances mostly use capacitive touch, and its use environment is complex and changeable, and the environmental changes will change the parameters of the touch system, eventually leading to the insensitive or misaction of the keys, affecting the user's use.Therefore, it discusses the influence of temperature and humidity in the environment on the touch system. At the same time, in order to solve the abnormal keys caused by environmental changes, a software adaptive algorithm scheme is introduced, which can effectively improve the adaptability of touch keys to environmental changes, and has guiding significance for the design of touch keys in home appliances.

Feed channel configuration within reverse osmosis (RO) membrane element greatly impacts the membrane fouling rate. Through analyzing four trending RO membrane, this paper summarized the membrane element with different feed channels. Computational fluid dynamics was used to simulate different flow channels, and their influences on parameters such as flow velocity, mass transfer efficiency and energy consumption were compared. The results showed that, when reducing water inlet and outlet widths, influent flow rate and wall shear stress was increased so that the membrane fouling rate was decreased.

Graphene shows a promising application potential in the field of photocatalysis due to the satisfactory performance, such as a strong chemical stability, high specific surface area and electrical conductivity. The antibacterial properties of graphene-based visible light catalytic composites were reviewed. Firstly, the photocatalytic antibacterial mechanism of graphene-based photocatalytic materials was briefly introduced, the positive role in the photocatalytic reaction process of graphene was summarized, including expanding range and intensity of light absorption, preventing the photoelectron-hole from recombining and facilitating the adsorption. The antibacterial research progress of various graphene-based visible light catalytic materials was introduced, including binary TiO₂/graphene composite (common, doping, defect), ternary composite and other semiconductor/graphene materials. Finally, it was pointed out that graphene-based visible light catalytic materials have a promising potential in the sterilization function of refrigerators. The application of graphene-based visible light catalytic materials under the effect of physical field would further improve the antibacterial effect, and the combination of sensor technology could further improve the intelligent sterilization function of refrigerators.

The nameplate of most lampblack machine on the market now marks air volume far less than the air volume when actual operation, especially the lampblack machine that is installed in low floor, this kind of air volume gap is more obvious. As a result of lampblack machine access public flue back row air volume will be reduced, bring about the lampblack in the kitchen cannot be discharged in time, for the precise and effective characteristic analysis of lampblack machine air volume is important. The effective exhaust air volume of the existing kitchen is firstly proposed, and then combined with the pressure distribution of the public flue, the pressure distribution of the public flue and the dynamic situation of the air blower are studied by means of model simulation and experimental testing, and the precise and effective air volume characteristics of the range hood are effectively mastered.

By analyzing the output of household range hoods and the status quo of plastic parts of waste range hoods in the past ten years, traditional waste plastic parts are mainly recycled for TVs, refrigerators, air conditioners, washing machines and other traditional household appliances. Range hoods account for a small proportion of waste and used The range hood cannot be fully utilized, resulting in a certain degree of pollution and waste of resources. The importance of recycling the waste plastic parts of the range hood is expounded. Taking the plastic check valve on the range hood as an example, describing the recycling process of the waste check valve through dismantling, crushing, cleaning, etc. Help achieve carbon peaking and carbon neutrality goals.

The mechanism of torsional vibration of rotary compressor is studied and analyzed. According to the characteristics of torsional vibration of compressor, the principle of dynamic vibration absorption is introduced to improve the vibration of compressor. The experimental results show that the vibration reduction can be achieved more effectively by designing the dynamic vibration absorber in the compressor than by adding the same weight. It provides an application example for vibration optimization of compressor.

Crankshaft is the core part of pump body of compressor. With the miniaturization, high efficiency and high quality of refrigeration compressor, the requirements for pump body parts become more stringent and the manufacturing process of crankshaft becomes more complicated. By analysing the material selection of crankshaft, local strengthening treatment, analysis of poor machining factors and surface treatment, etc. In order to avoid influencing factors reasonably and improve the quality of crankshaft during the manufacturing process.

Washer-Dryer being the prevailing machine in the current market. How to improve the drying efficiency is the main problem of machine industry. Based on the Computational Fluid Dynamics, simulated the water flow path in the rear-drum condensing structure of Washer-Dryer with the VOF model. The results of simulation correspond with the actual results by experiment, proved the accuracy of the model and simulation. On this basis, redesigned and improved the condensing structure, researched the factors which influence the water flow stability of rear-drum condensing structure. Computed the relationship with inlet-water cover plate and the distance of the outlet-water and the first diversion point of fillets. Finally, assured the range of design parameters by comparing the water flow path in different working conditions. Drying time is measured through the experiment indicated the results attain to expectation. CFD simulation is accurate and feasible to research the program, and the importance of guide is found to the future design in the same stucture of Washer-Dryer.

In order to study the influence of nozzle and ejector structural parameters on the primary air coefficient, the nozzle and ejector of a burner are modeled by two-dimensional parameterization, and the numerical simulation technology is used for simulation calculation. By analyzing the calculation results, the influence of each parameter on the primary air coefficient is summarized. In addition, using these rules to optimize the multi-parameter comprehensive structure of innovative five-ring fire gas stove, the primary air coefficient is effectively improved and the emission concentration of flue gas is reduced.

Carbon emission reduction and carbon neutrality are the foundation of a green circular economy for enterprises. The packaging materials for air-conditioning compressors are still traditional disposable packaging materials, which waste a lot of resources and are not conducive to the dual-carbon goal. Through the research on new materials and new structures of air-conditioning compressors, packaging appliances that can be used continuously and with higher reliability are developed, which provides theoretical basis and specific plans for the green recycling packaging of air-conditioning compressors. The packaging of air-conditioning compressors has changed from one-time use to repeated use, which significantly reduces the waste of packaging resources and promotes the carbon emission reduction of packaging during production and transportation. Compressor recycling packaging research, boost industry to achieve a green circular economy.

The passivation process of adding 500 ppb copper ion to 30 wt.% nitric acid passivation solution was studied to inhabiting bacterial biofilms on stainless steel of washing machine inner cylinder. The experimental results show that the passivation treatment changed the properties of the passive film on the surface of 430 stainless steel, and significantly improved the corrosion resistance, antibacterial and antifouling properties of the material. The pitting potential of the material was increased more than 200 mV and the antibacterial rate achieved over 99.99%, and does not affect the matrix structure. It has great prospects for application in the preparation process of stainless steel in the inner cylinder of washing machines.

The grille is a key component affecting the performance of the duct. For increasing the efficiency of the duct and decreasing the noise, it is studied by simulation that the influence of the performance of the different ducts. The research shows that the air volume of flat grille is larger than that of tubercle grille. After the flat grid is adopted, the air volume is increased by 34 % at the same speed, and the noise decreases significantly at the same air volume. Compared with the tubercle grille, the larger the vertical distance from the blade tip of the plane grid to the flow guides surface, the less the vortex near the fan motor is, and the more flow field is uniformed.

Aiming at the new environment-friendly airbag packaging structure, the accuracy of the uniform pressure airbag model is verified by static stiffness test and airbag parameter calibration simulation model. By establishing the clamping simulation model of washing machine, the clamping simulation calculation of the original polystyrene foam and polyethylene air cushion side cushion packaging structure is carried out, and the pressure of the side cushion on the box and the stress distribution of the box are obtained. It is proved that the air cushion packaging is superior to the EPS foam in terms of stiffness and strength, and the feasibility of replacing the side-foam is verified. Further, for the poor appearance of the washing machine box, a scheme of adding a high stiffness material - wood strip is proposed, and its effect is verified by simulation calculation. The clamping simulation method, especially the uniform pressure airbag model method, meets the requirements of enterprises for efficient and accurate simulation of new packaging structures.

In order to solve the problem of the flame swing of the burner in the gas water heater, the numerical simulation method was used to simulate the internal flow field of the fire. Combined with the flame shape analysis obtained from the combustion experiment, the cause of the flame swing is obtained, that is, there is a vortex at the lower end of the fire hole. At the same time, numerical simulation is used to verify the feasibility of solving the flame swing problem by optimizing the structure of the airflow channel between the shunt slot and the fire hole, which provides a reference for the design of the burner in the gas water heater.

The design of heat dissipation and waterproof of the electrical box of the outdoor unit of the air conditioner has a great impact on the safety and use experience of the air conditioner. In order to study the relationship between the two and the influence law on the safety and use experience of the air conditioner, summarize the design method, and conduct an experimental study on the heat dissipation and waterproof design of the electrical box. Through experimental research, the temperature laws of electronic components such as electrical boxes under different working conditions and frequencies are obtained. On the basis of this experimental research, the waterproof safety verification is carried out for outdoor units of different electrical boxes, and the influence law of the design of electrical boxes and the waterproof of electric control boxes is obtained, which provides theoretical guidance for the subsequent heat dissipation and waterproof of outdoor electrical control boxes.

In order to study the spray capability of the spray arm of the dishwasher, deeply analyzes the theoretical principle of the spray water velocity and total pressure, preliminarily discusses the improvement of the spray capability through the calculation formula, and compares the similarities and differences of spray water and its adjustment in the spray arm full pass mode and the alternate washing mode. Then, emphatically introduces the total pressure tooling based on the Pitot-tube theory. Taking the total pressure of the spray water as the parameter to evaluate the spray capability, the experimental results show that the alternating washing mode can form a significant pressurization effect, thus the spray capability and motion performance of the spray arm have been significantly improved. Finally, through the comparative cleaning test, it is further verified that the alternative washing mode can effectively improve the cleaning performance.

Since the implementation of energy efficiency, the heat efficiency of gas stove has been constantly updated, and the energy-saving index has become the focus of competition in the cookers industry. How to improve the heat efficiency of gas stove has become an important research direction of every enterprise. In addition to the direct relationship between the heat efficiency of gas stove and the burner itself, the pan support has a great impact on the heat efficiency, especially for some high-efficiency cooking utensils nowadays, the pan support plays a vital role in improving the heat efficiency. In order to study the relationship between the pan support and the heat efficiency so as to improve the heat efficiency of the gas stove, analyzes from the perspective of heat transfer, obtains the relationship between the pan support and the improvement of the heat efficiency and carries out practical verification. Finally, it is concluded that the size of the pan support energy accumulation plate, the smoke exhaust gap and the number of layers of the energy accumulation plate can all affect the heat efficiency of the gas stove.

Through real-field tests in high altitude and low altitude areas, and using the air pressure chamber to simulate the air pressure conditions as different altitudes, the heating tests were carried out on the normal working state of hand-held vacuum cleaner and the discharge operation state of power battery. By comparing the test data and combining the working principle of the test sample, the test results are analyzed. The influence of high altitude and low-pressure environmental conditions on the heating of vacuum cleaner and its power battery during operation is explained.

The chemical resistance and stress cracking of ABS and PS plastics were studied under normal and stress conditions by five general plasticizers selected in this paper. The results show that ABS plastics can be used in contact with plasticizers such as acetyl tributyl citrate (ATBC), dioctyl terephthalate (DOTP), chlorinated paraffin (CP), dioctyl adipate (DOA) and dioctyl Sebacate (DOS) under normal conditions; the above five plasticizers should be avoided to contact under stress conditions (1% strain). PS plastics can be used in contact with plasticizers ATBC, DOTP and CP, but the elongation decreases due to the influence of DOA and DOS under normal conditions; PS can be used in contact with ATBC and CP to avoid contact with DOTP, DOS and DOA under stress conditions (1% strain). When ABS and PS plastics are used in household appliances, the effect of stress should be considered when evaluating the effect with plasticizer. The presence of stress will reduce the plastic resistance to plasticizer until the plastic breaks.

Taking the current European type flat range hood as an example, a common problem with the range hood in the market is that there is a difference in smoking between the left and right sides of the range hood. Generally speaking (it should be determined according to the internal structure), if the air outlet is on the left, the smoking effect on the left is worse, and if it is on the right, the smoking effect on the right is worse, which is determined by the spiral case structure. In order to solve the market pain point, we are considering to change the smoking structure, adopt double impeller and single motor, and use gear link at the same time, which can not only solve the problem of uneven smoking, but also reduce the escape amount of oil smoke. We use virtual simulation and experimental verification to confirm that we can realize the intelligent interactive device——oil smoke escape recorder. This can solve the market pain points and optimize the internal structure, so as to achieve the optimal output of the whole control system, which greatly reduces the cost compared with double motor and double impeller.

Photoelectric switch has been widely used in household appliances, but its detection results are affected by many factors, and its output signal is prone to deviation due to external interference. In order to obtain accurate photoelectric switch signal and ensure its reliability in different application scenarios, the influence of structure assembly and supply voltage in application is discussed, and the improvement scheme is proposed to solve the problems.

In the gas-fired heating water heater, the heat exchange process of the heat exchanger is mainly convection heat exchange and radiation heat exchange. According to the combustion characteristics of the wall mounted furnace, the radiation heat exchange accounts for a small proportion and is mainly convection heat exchange. Introduce a new round tube heat exchanger for the atmospheric gas-fired heating water heater. The heat exchanger is composed of several parallel fins, and the fins are arranged with convex structures according to the simulation results, and on the premise of not affecting the flue gas resistance, the wind-proof folding edge is added on the upper part of the fin to change the flue gas flow direction, so as to improve the heat exchanger area of the heat exchanger. The heat exchanger is composed of round tubes, and the assembly is simple. The research shows that the circular tube heat exchanger with this structure has the advantages of small volume, high thermal efficiency, low cost, simple production process and modularization, and has high development value.

As an appearance decoration, the door and window screen of drum washing machine requires the material to have excellent light transmittance, mechanical properties, heat resistance and chemical resistance. In order to study the feasibility of using transparent methyl methacrylate styrene butadiene copolymer (MBS) material instead of methyl methacrylate styrene butadiene acrylonitrile copolymer (MABS) material in door and window screens, the physical and chemical properties of MBS material were tested and analyzed, and the chemical resistance, cold and hot shock tests of parts, as well as the transportation drop, high temperature and high humidity cycle and safety type tests of the whole machine were carried out. The results show that MBS material has low density, high light transmittance, excellent flowability and toughness, excellent resistance to environmental stress cracking, and excellent resistance to alcohol disinfectants and chlorine disinfectants. Meet the experimental requirements of parts and the whole machine, and can replace MABS materials to be applied to door and window screens.

In order to upgrade the gas water heater product A, the ignition and fire transmission performance test of the product A and other similar research programs was carried out. Analyzing the advantages and disadvantages of product A and other research programs in terms of ignition speed, fire transfer speed and combustion stability. And optimize the burner of product A according to the test results. The test results show that the gas water heater product A has the shortest ignition time and the best ignition performance. In terms of fire transmission performance, product A has a longer fire transmission time and has no obvious advantage compared with other research programs. In order to optimize the gas water heater product A, three optimization schemes are proposed and verified by experiments. The results show that the plan of adding 3 mm fire-passing sheet is the most reasonable, which can significantly improve the fire transmission performance of product A and improve its product competitiveness.

The pressure pulsation generated by the compressor during operation in the refrigeration system will directly affect the noise and vibration of the machine under test, and in order to carry out a joint analysis between pressure pulsation and noise and vibration, it is necessary to monitor the pressure pulsation of the compressor pipeline. According to the needs of testing, we first select the capture card, sensor and other hardware of the test device and then design and develop the supporting test software, this device can be used as a reference for relevant R&D personnel, with certain engineering application value.

Under the background of energy saving and emission reduction, the energy-saving design and optimization of household refrigerators have become a hot spot. The progress of energy saving and efficiency increase researches on employing phase change materials in household refrigerator was reviewed. The advantages and disadvantages of the application of phase change materials in key components such as the evaporator, the compartment, and the condenser were described. The feasibility of mass production of domestic refrigerator used phase change materials was also discussed. The study has shown that the use of phase change materials can reduce energy consumption and improve performance. However, in practical application, the comprehensive impact of phase change materials on the refrigeration system should be considered, such as on the working frequency of the compressor, on the refrigerant pressure, and on energy consumption under different working conditions. It was proposed that the evaluation system, user research and supporting technology can accelerate the market application process of phase change materials in domestic refrigerators.

Since there are complex factors influencing sleep, the effect of a single product is limited. The overall intelligent home design applies multiple factors including sound, light, electricity, air and flavor to take effect on human’s sleep, leading to the sleep aid by integrating sensing equipment to monitor the environment and the parameters of human body and combining artificial intelligence identification intervention to achieve sleep aid function. This article estimated the market volume of sleep-aid intelligent home, concluded the outlook of possible sleep-assisted solutions by exploring the environmental factors that affect sleep and provided the overview of intelligent devices’ effect in sleep monitoring and intervention. It had established the standardization system for sleep-aid intelligent home and recommended the top-down initiation of standards to break through the obstacles, for instance, “the undefined communication protocol” and “the fake IoT” that restricted the development of intelligent home industry.

With the rapid development of China's economy, the diet structure and habits of urban residents are also undergoing earth-shaking changes. The main contradiction of food nutrition and the diversified demand has become nowadays "kitchen revolution". The demand for ovens that can satisfy the taste, and cook fat-free, salt-free and healthy food is growing. When the user actually uses the oven to bake the food, it is easy to appear uneven heating and dry baking. Innovative PID intelligent temperature control system is designed for users' pain points. According to establishing the "pattern recognition method" of the oven and adopting the "multi-pid temperature control strategy", the full-mode high-precision temperature control is carried out, and the temperature in the cavity is uniform with the accuracy up to ±1°C. Therefore, it can effectively solve the problem of multi-layer simultaneous cooking, meet different needs of the color, aroma, taste, nutrition and health of baking ingredients, meanwhile, it can ensure the food crisp outside and tender inside, still keeping fresh. This technology can meet people's demands for intelligent operation and multi-function, improve high-quality cooking experience, which will be widely applied in industrial mass customization and spread in the whole industry.

With the improvement of living standards in recent years, people's demand for water consumption is more and more big, along with the increase of water heater best-selling volume, at the same time the bringing is a surge in electricity consumption. But since 2020 the arrival of the "double carbon" policy, the industry as a whole combines the intelligence with low carbon, and promotes the low carbon operation with intelligent functions. But there are no estimates of how much carbon savings smart technology can achieve in the day-to-day operation of water heaters. Therefore, through the in-depth analysis of quantitative calculation and qualitative research, the role of intelligent technology in low-carbon energy saving in this process is concluded, in order to provide reference and guidance for the industry and consumers.

As the number of elderly population increases year by year, the practical needs of the elderly people in various service scenarios have attracted more attention. The research and development show that there are very few types of refrigerators designed by the elderly at home and abroad. In order to solve the dilemma of poor user experience using smart refrigerators, through researching the physiological and psychological habits of the elderly group, investigating the needs and expectations of the refrigerator for the elderly groups, from the foundation from the foundation. The design, system design, and interactive design provides a new aging refrigerator design idea for the refrigerator designer.

In recent years, with the diversified development of diet, people's health awareness has been improved. The electric steam oven that keep the true taste and retain the original fresh nutrition enter thousands of households. When the user cooks, the steam condenses to form a large amount of residual water at the bottom of the inner cavity, which is easy to breed bacteria for a long time and has adverse effects on health. Through innovative design more than cooking water automatic recovery mechanism, main design system with filtration system, prevent return flavour and configuration professional pump drainage system, and building model functional prototypes, design the program logic to the residual water discharge of intelligent control, and built the model functional prototype, designed the program logic to control the discharge of surplus water intelligently, and carried out comparative verification and testing on the cooking of food materials with no surplus water, and innovatively formed the intelligent control of surplus water technology and intelligent cooking system equipment. The results show that the application of the intelligent control of residual water technology in the steaming oven not only effectively prevents the residual water containing cooking impurities from evaporating again and causing the taste of food materials, ensuring the quality of healthy and fresh steaming, but also solve the difficulty of manual cleaning of residual water, improve user experience satisfaction and reputation, and promote the green and healthy development of intelligent kitchen electric market.

Test water and test load are the basis of the performance test of the clothes dryer. In order to study the influence of water and load on the drying performance of the clothes dryer, the test method was summarized and the test conditions of the clothes dryer were simulated. The effects of different water quality and load on drying were obtained through experimental study. Through analysis and research, the factors and levels of this experimental study were determined. MiniTAB software was used to conduct full-factor experimental design and variance analysis of all test data. The law of the influence of test water and load on drying was obtained, which provided theoretical guidance for subsequent performance testing and research and development of clothes dryer.

Visual images have always been an important source of information for people to obtain from the outside world. Image segmentation is to segment an image based on the underlying semantic information such as color, space, and texture of image pixels. Superpixel image segmentation uses superpixel blocks instead of pixels as the basic unit of image processing, which reduces the computational complexity of subsequent algorithms. Superpixel algorithm cannot take into account real-time processing and processing accuracy well, and improving processing efficiency and accuracy will be an important task for superpixel image segmentation algorithms that need continuous research and improvement.

With the continuous popularization of smart homes, voice interaction has gradually become an important interactive entry for users to control home appliances. Due to the diversity of types of household appliances and the richness of functions of a single device, it is difficult for ordinary users to control the household appliances through accurate voice control commands due to their lack of understanding of product function definitions in the early stages of use. To address this problem, proposing a semantic-guided reply technique that combines text classification, entity extraction, and knowledge graph schemes. Firstly, the text classification method is used to recall user requests containing valid intentions, and then semantic analysis is carried out by combining entity extraction and knowledge graph technology. Using 3 months of user voice interaction data to test and verify the technology, the correct rate of guidance response reached 87%, which can effectively guide users to use voice commands to control home appliances.

Dehumidification technology is widely used in many fields. The traditional dehumidification technology is not enough to meet the diversified use needs. Summarizing the categories, working principles, advantages and disadvantages of different gas dehumidification technologies, and points out their future development trends. It is found that dehumidification technology varies with use scenario. Runner dehumidification and liquid absorption dehumidification have a good application prospect in air-condition dehumidification, and semiconductor dehumidification, membrane dehumidification and solid adsorption dehumidification are more suitable in small space for refrigerator environments, which provides reference and evidence for the application of air dehumidification technology in the field of household appliances.

Speech synthesis is one of the key technologies of voice interaction on intelligent home appliances. The quality of synthesized speech directly influences the users’ intelligent interactive experiences. For the problem that the duration of synthesized speech is deterministic and lack of rhythms, utilizing the flow-based stochastic duration predictor to optimize the mainstream Glow TTS model, and an experiment was conducted with Japanese as the research object. The result indicates that the accuracy of speech duration prediction and the quality of synthesized speech are greatly improved. It can provide guidance for the following optimization study on speech synthesis of intelligent home appliances.

With the improvement of people's living standards, users' requirements for home cooking are also increasing. Users expect to be able to cook richer and tastier food with ovens and other appliances. However, for many recipes, judging the maturity of food requires more experience, and the cost of cooking time is high, so users prefer to succeed at once. In view of the user's pain points, the sensor information changes of some kinds of food in the cooking process were studied, and the taste parameters were tested at different end times to find the most appropriate ripe time, so as to realize the automatic perception of oven cooking food maturity, to achieve the best cooking effect and meet the user's expectation.

According to the fan-air duct characteristic curve, the law of changing of the fan system depending on the duct resistance is analyzed, as well as the relationship between air volume, power and revolution speed and other parameters on the premises of constant revolution speed and constant air volume based on the experimental data, and from which a constant air volume control method based on fan power checking is raised. The error of the static pressure auto-identified by this method can be maintained within 4%, and within 6% for air volume.

With people's higher requirements for the detergency of washing products, the washing industry needs products with stronger and wider detergency. For different stubborn stains that are difficult to remove, special washing machine parameters can be designed. This demand of consumers has prompted the washing industry to conduct in-depth research in this area. According to the development trend of washing machine and the specific demand of the market, study the influence of washing parameters (washing time, temperature, rotating speed, turning and stopping ratio) of washing machine on the detergency of five kinds of the standard stain, design the washing program parameters of washing machine, establish a mathematical prediction model between washing parameters and detergency, improve detergency of clothing, and can also provide reference for developing the washing program of intelligent washing machine.

With the popularity of fresh air conditioning, air conditioning with fresh air function is constantly launched in the market. As the main core index of fresh air conditioning, fresh air volume affects the user experience. In order to make the design optimal and reduce the loss of fresh air volume, through the analysis of the structural components of the fresh air pipe components of the fresh air module system, and then optimize the combination of fresh air pipe components to reduce the friction coefficient along the fresh air pipe and increase the inner diameter of the fresh air pipe; And through the structural simulation analysis of the air outlet parts, so as to optimize the diversion structure of the air outlet parts to improve the air boundary layer and eddy current at the outlet, so as to minimize the influencing factors of the parts connected with the new fan system, and improve the fresh air volume of the whole machine, accumulating empirical data for the subsequent design.

In the context of the epidemic, the demand for healthy home appliances has increased, and the healthy development trend of the household air conditioning industry is obvious. Briefly expounds the health technology used in Japanese household air conditioning from three aspects of air conditioning self-cleaning, indoor air quality improvement and intelligent control. In terms of health technology, Chinese household air conditioning companies can start with all aspects of cleaning, sterilization and purification, and intelligent improvements, including filters and wind deflectors.

As a large energy consumption, gas-fired heating water heaters is a big burden of national heating costs. Under the background of "carbon peak, carbon neutralization" goal, energy consumption problem, which is one of the core problems that must be solved in further development of the industry, is more prominent. With the advent of the intelligent era, intelligent gas-fired heating water heaters can greatly reduce gas consumption and reduce residents' economic burden on the basis of meeting users' heating needs by learning users' usage habits, intelligent temperature control and other ways. By setting up a scientific and reasonable test environment, and through a large number of test monitoring, the energy saving effect of intelligent technology on gas heating water heaters is obtained.

In recent years, many air-conditioning products are equipped with ultraviolet sterilization function, which aims to sterilize and disinfect the indoor air and the interior of the air conditioner. However, the sterilization effect and biosafety of some products are not ideal. Through analyze the design factors of the application of UVC-LED sterilization technology in air conditioners, provide guidance and reference for the application design of UVC-LED technology to improve the sterilization effect and biological safety of UVC-LED sterilization air conditioner.

Based on the analysis of electric pressure cooker user behavior data, it is clear that user habits have a strong regularity. Further clustering analysis of users reveals that there are large differences between different types of users, and the gap is further increased when it comes to individual users. Through the time nodes of the local electric pressure cooker usage data, and the information of function options and setting parameters, use the machine learning model XGBoost and statistical analysis knowledge to carry out multi-dimensional data mining, and interpret the user usage habits of electric pressure cookers, and combine with the existing iot function, and complete the data of individual users through the user's historical reservation time, use function content, etc. The data of users' historical reservation time and function content can be used to remind individual users of the reservation and the intelligent recommendation and prediction of users' function parameters, so as to strengthen the intelligent function of electric pressure cooker for the guidance of users' use behavior and further enhance the intelligent interaction between kitchen appliances and users.

With the development of the Internet and sensors, the smart home appliances of the Internet of Things have also been popularized, to achieve efficient management and intelligent perception of home appliances. In whole-house smart home appliances, devices are connected to each other centered on a gateway. Therefore, smart home appliance gateway is very important, but its centralized structure has multiple security vulnerabilities, such as integrity, authentication and availability. In order to solve these problems, propose a blockchain based gateway architecture design to deal with possible attacks on smart home gateways. The overall network architecture consists of three layers, the device layer, the gateway layer, and the cloud layer. Blockchain technology is applied at the gateway layer. The data is stored and exchanged in the form of blocks, realizing a decentralized architecture. Blockchain ensures the integrity of internal and external data of smart appliances, and provides availability through authentication and efficient communication between network members. Implementing the smart home appliance gateway architecture based on the technology of the Ethereum blockchain, and evaluates its response performance, including security response time and accuracy. From the evaluation results, the solution proposed is superior to the existing solution.

As an additional function of the range hood, the self-cleaning and non-disassembly washing technology of the household range hood effectively improves the use experience of consumers. Through the study of the working principle and key technologies of self-cleaning and non-disassembly washing, analysis of self-cleaning, non-disassembly washing technology can achieve the effect. Through discusses the development prospect and market situation of self-cleaning and non-disassembly washing technology, and provides guidance for the development of range hood industry, and provides reference for consumers to choose appropriate products.

In order to improve people's quality of life and solve the problem that the traditional range hood needs to be manually set during use, an intelligent range hood control system with diverse functions will be designed to use voice commands to select the working state of the range hood. It has the functions of selecting the wind force, lighting switches and natural gas leakage detection through voice control. The basic requirements of modern range hood are analyzed, and the hardware design scheme of intelligent range hood based on voice control is proposed; The details of each hardware module of the intelligent range hood are constructed; Finally, the corresponding voice commands are used to test the wind control, lighting switch and alarm functions of the designed intelligent range hood system, which proves the accuracy and practicality of the design.

Smart home scene is an application technology based on artificial intelligence, Internet of Things and cloud computing technology, which reflects the psychological activities and behavioral interaction of people in the smart home environment. The experience of the smart home scene directly affects the user's willingness to build a device network, which is related to the sustainable development of the enterprise. This research aims to construct big data and small data analysis indicators, so as to comprehensively evaluate the user experience of smart home scene, and to provide reference for smart home technology improvement and product optimization.

With the popularity of air conditioners, the use of air conditioners by modern people is no longer limited to the cooling and heating effect, but more to the pursuit of healthy air conditioners. With the development of the epidemic in recent years, people have further improved the concept of health, so there are a series of air conditioners with the concept of sterilization. At the same time, with the release of the three child policy by the government and the increase in the birth rate of infants, the frequency of using air conditioners in summer has been further improved. At the same time, due to the imperfect development of infants' respiratory system, they are easy to be infected with bacteria. Therefore, when using air conditioners in summer, there are higher requirements for the treatment of ash deposition and sterilization on the indoor side of air conditioners. They no longer only require refrigeration effects, but more healthy and comfortable air conditioners. Therefore, this paper starts from the fixed frequency air conditioner that has been used most frequently in the past, analyzes the high-temperature sterilization and self-cleaning function of the air conditioner through a series of functional logic verification and test verification, noise experience and other aspects, and tests and verifies all aspects and all working conditions, so as to ensure the reliability of the air conditioner and realize the high-temperature sterilization and self-cleaning function at the same time.

With the rapid development of the social economy and the improvement of people's living standards, water heaters have become a necessity for public life, and the current number of water heaters exceeds 350 million. Water heaters are household appliances with high energy consumption. How to reduce energy consumption and reduce carbon emissions is a technical issue faced by smart home water heaters. Simple intelligent control cannot bring new development opportunities to the industry. Integrate with AI technology, combine knowledge graph capabilities with machine self-learning, and build a control system based on knowledge graphs with self-learning capabilities. Electricity data, automatically adjust the operation mode of the equipment, so that the intelligent water heater always automatically runs in the best energy-saving mode. The State Grid data provides peak and valley electricity data in different regions, the knowledge map improves the variable factors of the self-learning algorithm, and the AI technology improves the user interaction experience of the device. The combination of the control system and the algorithm realizes the application of low-carbon technology in smart water heaters, providing a new direction and growth momentum for the green development of the household appliance industry.

With the development of AI technology, the Open-Door smart vending machines are widely used instead of the traditional vending machines. The normal refrigerator can be changed into smart vending machine by adding cameras, lock, and control box. The smart vending machine has less cost but better shopping experience than the traditional vending machine. In order to solve the goods recognition problems of the smart vending machine an algorithm system is proposed. By applying different AI algorithms and technologies to analyze the videos captured by the cameras it is possible to give accurate recognition result of the goods that the customer purchased. The experimental results proved that the proposed algorithm system is qualified for the practice usage of the smart vending machines.

Based on the thermodynamic specific heat formula and the ideal state equation, simplified the washing drying machine into an ideal state model. By using the temperature curve change of NTC in the water heating tube during the whole drying process, we can obtain the functional relationship between the fabric moisture content and the drying time. On the basis of a large number of experimental data, the total drying time of the fabric is derived; At the same time, in the final drying stage, the temperature in the cylinder will evaporate with a large amount of fabric moisture, which will reduce to a certain extent compared with the temperature in the dynamic equilibrium period. Therefore, we collected a large number of experimental data and summarized the functional relationship between the final moisture state of the fabric and this temperature difference. Based on the above two kinds of intervention judgment logics, a mathematical equation model is established. Through software optimization and combination, the dual intelligent intervention judgment is finally realized, which greatly meets the user's drying experience.

Sweet potato is rich in nutrition and has a unique flavor, which is deeply loved by consumers. In China, there are various cooking methods, and the dishes have more choices. The quality of cooking materials varies greatly with different cooking methods. Taking sweet potato as the research object, studing the effects of three cooking methods on the edible quality of sweet potato: single steaming, steaming and baking combination and single baking. The effects of different cooking methods on water content, soluble sugar, starch content, texture and sensory evaluation of sweet potato were analyzed. The results showed that from the analysis of physical and chemical indexes, the order of water content from high to low was: steaming alone > steaming and baking combination > baking alone. The sequence of soluble sugar content from high to low is: single baking > steaming baking combination > single steaming. The order of starch content from high to low is: steaming alone > steaming and baking combination > baking alone. From the texture data, steaming and baking combination cooking shows great advantages in texture and taste. From the perspective of sensory evaluation, the baked sweet potato alone is more popular with users. The three different cooking methods have their own characteristics. Users should reasonably choose different cooking processing methods according to different needs.

The texture of rice made by electric cooker was analyzed and determined by the method of total texture. By comparing and analyzing the texture properties of rice at different positions in the rice cooker, it is found that there are some differences in texture properties of rice at different positions in the rice cooker. Through will break up after the rice quality and structure parameters as the test value of different positions inside the pot rice quality and structure parameters of the single sample t-test analysis, found that the different position of rice of hardness, elasticity, viscosity, chew, gumminess, adhesiveness and other indicators measurement after their respective average and break up there was no significant difference between the results of these indicators. The uniformity index δ and whole index μ of texture parameters were introduced to improve the scientific evaluation of the taste of cooked rice in rice cookers. It provides reference for the establishment of taste evaluation system of rice cooked by electric cooker.

With the increasing demand for healthy cooking and reasonable diet, it is of great significance to establish a scientific, reasonable and comprehensive general quantitative method from the perspective of human sensory experience, which is applied to the evaluation of cooking quality of kitchen electrical products. Taking the household electric oven as an example, based on the reasonable construction of the sensory evaluation index system and quantitative standards of cookies in cooking samples, the sensory evaluation data of cookies in the baking mode of the two control prototypes were collected from 10 optimal evaluators, and the sensory comprehensive evaluation model of cookies was established by using the fuzzy mathematics method. The sensory effects of cookies in the baking mode of the two prototypes were compared and analyzed, and the results showed that the sensory comprehensive evaluation method based on fuzzy mathematics could be effectively applied to the evaluation of cooking quality of kitchen electrical products. This method provides an effective means to optimize and improve the evaluation of cooking quality of kitchen electrical products, reduce unnecessary research and development costs, and also provide theoretical support for standardizing the healthy and sustainable development of the industry.

Air conditioning products combine all kinds of intelligent control technology and operation information collection technology, and have strong self-troubleshooting ability. With the popularization of Wi-Fi function in air conditioning products, the remote after-sales service of air conditioning products is gradually realized. The air-conditioning products collect operation information, and then communicate with the website server through Wi-Fi module, so as to realize the remote after-sales service of air-conditioning products. Compared with the traditional air-conditioning maintenance methods, they have greatly improved the maintenance efficiency. The use of the system simplifies the air conditioning after-sales service process, improves the product maintenance efficiency, and is conducive to promoting the improvement of the quality of air conditioning products.

To focus on the user's sensory and behavioral needs, so that the integrated stove can be more in line with the user's real use scenario. Combining qualitative and quantitative research methods, household interview, on-site observation, online questionnaire verification and other methods were used to explore the implicit demand of integrated stove users. UTB requirement model is used to verify the feasibility and practicability of transforming user requirements into products by combining the user's implicit demand, technology development difficulty and market maturity. This method can effectively excavate the implicit demand of integrated stove users and provide strategic support for the subsequent design practice.

At present, the environmental protection standards and regulations of electronic and electrical products in Asian countries are different, resulting in poor standard compatibility in the field of electronic and electrical products, which is easy to produce technical barriers to trade and affect product exports. Through the comparison of environmental protection standards and regulations for electronic and electrical products in 9 countries or regions in Asia, and the interpretation of differences in implementation methods, restricted substances and labeling requirements, it provides opinions and references for China's electronic and electrical product manufacturers and their supply chains to meet the requirements of domestic and foreign green environmental protection regulations and improve the green environmental protection quality of electronic and electrical products.

Along with the development of the intelligent and networked, more and more appliances used in the electronic circuit containing software, how to improve the security of the electronic circuit containing software, has become the hot topic nowadays. By studying a simple and universal method to improve the safety of induction cooker. It is safety software evaluation, used to evaluate the safety of induction cooker. First of all, research the basic theory about safety software evaluation, including what is the safety software evaluation, the goal and object of software evaluation, process, applicability. Based on this, research the key techniques about safety software evaluation. There is the application of the safety software evaluation on the induction cooker. First, research the system and features about the induction cooker. Then research the applicability of the safety software evaluation and the protection. At last, the realization of the safety software evaluation on the induction cooker.

Electrical insulation resistance test is a test of product insulation. Taking the two capability verification plans that have been implemented as an example, the preparation process of the test samples of the two capability verification plans, and the improvement and optimization of the shape design and internal circuit of the test samples are described in detail. After the feasibility verification, it is applied to the implemented capability verification plan. Then, according to the test reported by the laboratory during the implementation process, the key influencing factors of insulation resistance test are analyzed in detail.

Low carbon energy saving is the unified goal of China's development in recent years, and the home appliance industry is no exception, and there are two stages that have the greatest impact on this are: the home appliance manufacturing and transportation side and the residents' daily life use side. The former is easier to achieve the goal because of the unified management of the enterprise side, however, due to the dispersion and individuation of the latter, it is difficult to measure the carbon emission of intelligent home appliances in the operation stage. By studying the evaluation methods of energy saving and emission reduction in the operation of intelligent home appliances, and proposes a series of standards including evaluation principles, evaluation indicators and calculation and evaluation methods to fill the gap in this part.

To study of the present situation of needle flame test in China, on the basis of the existing standards and equipment, new risks are found through comparison with foreign countries. This risk can have serious and extensive influence, involving production, testing and sales, which needs attention and corresponding control measures should be taken.

The electric pressure cooker is an upgraded product based on the rice cooker combined with the advantages of the ordinary pressure cooker. It solves the pressure safety problem of the pressure cooker. The increase of the pressure in the pot can speed up the cooking process of the food and save the cooking time. The implementation of electric pressure cooker energy efficiency standards can provide a standard basis for the industry, promote electric pressure cooker manufacturers to improve their products, and contribute to the healthy development of the electric pressure cooker industry. The research can provide a reference for the laboratory of electric pressure cooker manufacturers and third-party testing institutions to control the testing process and improve the measurement accuracy.

At present, washing machine products have become one of the indispensable electrical appliances in our family. The washing ratio is an important indicator that users will pay attention to when choosing washing machine products. By analyzing the uncertainty of the washing ratio test by taking the pulsator automatic washing machine as an example, and provides a reference for enterprises to improve the performance of washing machines, improve the quality of washing machines, and for third-party testing institutions to improve the accuracy of washing machine performance testing.

Creepage distance and clearance test is a basic test item for compulsory certification of electrical products. Laboratories can verify and improve their testing capabilities in relevant testing fields by participating in proficiency testing. CNAS requires laboratories to regularly participate in proficiency testing in related testing fields. In the process of proficiency verification of clearance and creepage distance, it is necessary to pay attention to the selection of appropriate test equipment, and to select the preferred path considering standard requirements and prior technical decisions. Participating in the proficiency verification of creepage distance and clearance test will help to understand the laboratory's understanding and mastery of standards, and improve the laboratory's specific knowledge of creepage distance and clearance.

This article refers to GB/T 10125-2012 "Artificial Atmosphere Corrosion Test Salt Spray Test for Inspection" standard requirements, taking key household appliances (electroplating parts, screws) as examples, combining the current test process and analysis of related problems There are four main misunderstandings in the process of salt spray testing of household appliances parts. Analysis shows that first: the salt spray test cannot directly determine the corrosion resistance of the material in the use environment; second: the test method selected for the salt spray test is unreasonable; third: the salt spray test does not incorporate the actual production process; fourth: the results of the salt spray test are not fully understood.

To provide a means of monitoring TVOC of rubber products in electronic and electrical products, establishes a method for the determination of dibutylamine in rubber products by gas chromatography-mass spectrometry. Methanol was used as the extractant for solvent extraction, ultrasonic extraction was performed, and the separation was performed on an Aglient HP ULTRA 2 column, and mass spectrometry analysis was performed using an electron bombardment ion source (EI) with selected ion monitoring (SIM) mode. The data showed that the content of dibutylamine in methanol was linearly related to its characteristic ion peak area. The average recoveries in the blank samples were 95.3%~100.2%, the relative standard deviations (RSD, n=7) were 0.8%~2.6%, and the low limit of determination was 0.085 mg/kg. Test washing machine observation window samples in the dibutylamine content, test results show that the content is high, there is a hidden risk of air pollution in indoor use, baking at high temperatures is more serious, long-term effects on human health.

With the rapid development of the internet of things and artificial intelligence technology, household appliances are gradually intelligent, and the intelligent technology of gas water heater is also advancing rapidly. However, whether the intelligent characteristics of gas water heater on the market really meet the needs of consumers, and how to judge good from bad for the same intelligent function, to solve these problems, a set of concrete and operable evaluation standards are urgently needed. The issue and implementation of T/CAS 485-2021 "Intelligent technology of intelligent home appliances special requirements for gas water heater" is a good solution to this problem. Through extensive market research and test verification, the standard makes clear requirements and test methods for the core intelligent functions of intelligent gas water heater one by one, helping and guiding the intelligent development of gas water heater.

Based on the double compressor semi-open heat pump drying system, the experimental test bench was established, and the semi-open heat pump drying system used for tobacco drying was analyzed. The experimental results showed as follows: (1) During the whole tobacco curing process, the average performance coefficient of the integrated heat pump system was 2.90, the maximum instantaneous performance coefficient of the integrated system was 3.26, and the SMER was 2.42 kg/(kW•h), showing high energy efficiency. (2) Compared with coal-fired flue-cured tobacco, the average SMER of the semi-open heat pump drying system is 3 times higher than that of coal-fired flue-cured tobacco, and the cost of drying 1 kg of dried tobacco leaves is saved by 28.6%, with significant energy saving advantages and economic benefits.

In recent years, the demand for household appliances for infants has increased significantly. Various small household appliances that help raise infants have attracted the attention of young parents and become the new favorite of scientific parenting. Unlike ordinary household appliances, infant household appliances need more stringent standards to regulate and guide the market, but the standards and specifications in this field have not been established, and there is a lack of index requirements that can reflect the product performance and functional characteristics. Consumers cannot quickly choose the right one when purchasing products. The release and implementation of infant household appliances series standards effectively solve this problem. Taking small household appliances for infants as the research object, and focuses on the relationship between infant household appliances and mother infant industry, as well as the practice and research of the formulation ideas and core indicators of infant household appliances series standards.

In order to solve the problem that the traditional detection of finished product weight depends on manual sampling and the number of sampling is small, a finished product weighing system and the assembly line using the system are designed. The structure part is the traditional frame and the plate chain drive system installed on the frame. A weighing sensor is installed on the chain plate of one section, and multiple sensors are arranged successively. The support surface of the sensor protrudes from the chain plate surface, which can support the finished product and weigh it. The control part is mainly composed of 51 single-chip microcomputer and CYT-206 micro weighing sensor, etc, by weighing sensor testing finished product weight, and will return value to MCU, MCU compared with standard product weight range of presetting, if numerical weight exceeds the standard product range, single-chip microcomputer control alarm sound and light alarm. In order to prompt the operator to take the unqualified finished products offline in time to analyze and study, effectively save manpower and time, avoid the unqualified finished products from leaving the factory, improve the quality assurance level of finished products.

According to the requirements of Appendix B of T/CAQI 210-2021 "Fruit and Vegetable Cleaning Device", GB 2763-2021 "National food safety standard—Maximum residue limits for pesticides in food", and JJF 1059.1-2012 "Evaluation and Expression of Uncertainty in Measurement", a method for the determination of the spiked content of DDVP in fruits and vegetables by gas chromatography was established, analyze the test process, find out the factors that affect the uncertainty, and evaluate and synthesize each component. The results show that the uncertainty introduced in the sample processing process is the largest, followed by the preparation process of stock solution and standard solution, and the uncertainty introduced in the linear fitting and repeated determination of samples is small. When the standard added amount of dichlorvos is 0.3 mg/kg and the expanded uncertainty is 0.048 mg/kg, the measurement uncertainty report is: w=(0.30 ± 0.048) mg/kg, (P=95%, k=2).

At present, with the development of society, air conditioning systems are widely used in various buildings, and fault detection of air conditioners is also considered to be one of the main challenges facing modern buildings. Because the data on the operation of the air conditioner comes from a large number of sensors, it is difficult to detect and detect at an early stage. Although in recent years, the use of statistical modeling and machine learning methods has been widely used in air conditioning fault detection and diagnosis. However, early detection is still a difficult task, and it also faces the problem of poor accuracy of fault detection. By combining a hybrid classifier of a random forest and support vector machine are used for fault detection and diagnostic applications of air conditioning systems. Experiments show that this kind of mixed classification model of random forest and support vector machine has high accuracy in fault classification, and the requirements for training samples are not high, and fewer training samples can be used to train and obtain better accuracy.

In the context of scientific and technological progress, the "new refrigerator" products are changing with each passing day. New materials, new parts, new functions in the upper layer of the refrigerator, the traditional inspection method can not meet the needs of the new generation of refrigerator quality inspection. In order to meet the needs of refrigerator inspection, improve the efficiency of inspection, improve the quality of inspection, and reduce the pressure of inspection personnel, the technicians of refrigerator production line jointly researched a series of automatic, intelligent and integrated inspection schemes according to the quality inspection pain points and the performance and process characteristics of the "new" inspection requirements. Through the analysis and summary of these detection schemes, it can be seen that AI detection has been more and more applied in refrigerator detection. As AI inspection technology matures further, its use in refrigerator inspection will increase in breadth and depth.

Modal analysis is of great significance for product design optimization, engineering structure stability, damage detection, etc., and vibration testing technology is the basis of modal analysis. For the contact measurement test based on piezoelectric sensors, contact sensors, such as acceleration sensors, must be installed on the workpiece surface. Therefore, the non-contact testing technology represented by laser Doppler vibration measurement technology can avoid the influence of additional mass and has advantages for such testing. In order to understand the performance of different test tools and means in the actual engineering environment, so as to obtain higher precision measurement data. The accuracy comparison between piezoelectric sensor and Doppler laser vibrometer in modal testing is carried out. It is concluded that the modal accuracy of piezoelectric sensor and laser vibrometer is the same in low-order mode, while in high-order mode, laser vibrometer has advantages in measurement accuracy, no additional mass effect and vibration mode performance.

The 24-hour inherent energy consumption coefficient of water storage electric water heater has a great impact on the energy efficiency grade of products. In order to study the method of improving the energy efficiency grade, the fluid solid coupling heat transfer simulation of water storage electric water heater is carried out, the optimization direction of reducing the 24-hour inherent energy consumption coefficient of electric water heater is analyzed, and several specific solutions are provided. The effectiveness of the scheme is verified by the established CFD simulation analysis method. The optimization scheme of liner support can effectively reduce the 24-hour inherent energy consumption coefficient by 0.008. The two schemes of reducing the liner by 1 mm and moving the liner down by 1 mm can effectively reduce the 24-hour inherent energy consumption coefficient by 0.024 and 0.015, respectively.

With the development of technology and the improvement of people's living standards, more and more attention has been paid to the functions of household appliances related to users' senses. Briefly introduces some basic concepts and methods of sensory evaluation, and mainly introduces the application status of sensory evaluation method in household appliance detection, and then prospects the application of sensory evaluation in household appliance products and detection.

High-quality development must be closely linked with meeting the people's needs for a better life. Intelligent home appliance is not only an important direction of high-quality development for the household appliance industry, but also an important means to meet people's better life. Taking the assessment of intelligent ability of the intelligent home appliances as the research object, analyzing in detail the evaluation object, evaluation principle, evaluation system and calculation method, focusing on how to plan and design smart home products under the demand of better life.

T/CNLIC 0040-2021 "Household refrigerator-Test method and evaluation requirements for infants and young children food preservation function" has been issued and implementation in December 27, 2021 by China National Light Industry Council. This group standard specifies the technical and evaluation requirements for the storage function of household refrigerators for infants and young children, and describes the corresponding test methods. As the first refrigerator group standard focusing on the storage function of infants and young children food in China, the implementation of this standard will be conducive to the technical innovation of household refrigerator products and the standardized development of refrigerators for mother and infant.

The energy efficiency of the AC ventilation fan is tested according to the requirements of the GB 32049-2015 standard. Factors such as testing equipment, testing environment, testing methods, and testing personnel have a greater impact on the ventilation fan air flow test and energy efficiency test. The essence of uncertainty is caused by the level of measurement technology and the ability of testers. Through the evaluation of the uncertainty of the ventilation fan energy efficiency value measurement, it is found that the differential pressure of the nozzle of the air volume test device and the size deviation of the nozzle are the main influencing factors. The laboratory can learn from these two factors, analyze each aspect, formulate corresponding improvement plans and quality control plans, and improve the relevant testing capabilities and test accuracy of the laboratory.

Global energy shortage and climate deterioration have become major problems facing all mankind. Using off-grid solar products, as one of the important new energy products, is one way to solve energy shortage and other problems. Off-grid solar photovoltaic products generate electricity through photovoltaic modules and provide energy supply for lighting, household appliances and other products through energy storage batteries and control devices. In 2022, two Chinese version of the IEC standards for off-grid solar products are released for the first time in worldwide, which provide a unified test method and an evaluation standard for off-grid solar products. Based on many years of testing experiences, the laboratory analyzed some important items according to the Chinese version of two IEC standards in detail, which could help manufacturers and users of standards well understand the technical requirements of the standards and could contribute to the improving quality of off-grid solar products.

With the popularity of microwave oven products, people have begun to pay attention to the efficiency value of microwave ovens. The test process of microwave oven efficiency values is complicated and greatly affected by factors such as test environment, equipment and personnel operations. The measurement uncertainty evaluation can determine the influencing factors of the microwave efficiency test results, and improve the laboratory's detection ability and test accuracy. At present, there are two methods for uncertainty evaluation: GUM method and MCM method. These two methods are used to evaluate the uncertainty evaluation of microwave efficiency value measurement, and the results obtained by the two methods are compared and verified, and the two uncertainty results are basically consistent.

With people's in-depth understanding of the harm of cooking fume in the kitchen, only upgrading the product technology of range hood can not fully meet the needs of healthy home cooking environment. The smoke control and flow diversion technology of gas stove gas curtain proposed in this paper applies air hydrodynamics, and the air curtain is designed around the gas stove with a certain Angle of incline and all directions. And through the design verification test, verify that in different types of range hood products work, the gas cooker gas curtain smoke control and diversion technology can effectively reduce the dispersion rate of oil smoke and other performance indicators, can well improve the kitchen cooking environment.

The characteristic of the energy efficiency test of EU water heater which is different from the national water heater standard is that the energy efficiency test needs to draw off the water, and the draw-off water is not one-time. The key of the test is to solve the control of draw-off water on the energy efficiency test. Analyzes and studies the data acquisition rate, process data processing and test process control of the test system affecting the draw-off water energy content control, puts forward the scheme and the draw-off water energy content control strategy for EU water heater energy efficiency test, and applies it to a new EU water heater energy efficiency test system. Through the test and comparative study for a water heater, the draw-off water energy content control is further verified and analyzed, and the accuracy of draw-off water energy content control reaches ±2%.