VRF system, because of its flexible control and high efficiency, is widely used in office and residential buildings with "part time, part space" requirement. However, in winter intermittent heating mode, after starting VRF system, although only some rooms need to be heated, each room still needs to go through a long time to reach setting temperature. This process would also affect the thermal comfort of the room. A VRF system of a residential building in Nanjing is taken as an example to establish a performance model of startup process of the VRF system. The feasibility of rapid heating is analyzed through the TRNSYS-TRNBUILD simulation platform, the VRF system performance and indoor comfort improvement effects under this scenario are analyzed. The results show that: in the rapid heating mode, the advantage of wide range of VRF capacity adjustment can be used for heat scheduling. The rapid heating of local room can be realized. Compared with the conventional heating start-up mode, the adoption of rapid heating mode will improve the system energy efficiency COP and indoor comfort.

Piezoelectric ceramic loads work through the principle of inverse piezoelectric effect, and the driving voltage of the load often adopts AC output. By changing the voltage amplitude of the AC output, the swing amplitude control of a cantilever beam based on piezoelectric ceramics can be achieved, often used in engineering fields such as turbulence and active heat dissipation. If analog gear control is used for amplitude modulation control, there will be high switching current stress, limited optional swing, and high cost. Proposes a virtual isolation digital controlled PWM duty cycle regulation method, which achieves stepless regulation of output voltage by controlling the current size of the bus voltage feedback loop, and also solves the problem of high current stress during switching. This scheme realizes that the peak to peak value of AC output voltage can be dynamically adjustable between 12 V and 430 V at 12 V input, with low cost, and also analyzes the overall conversion efficiency.

Based on the dynamic grid CFD simulation of the compression chamber and combined with the characteristics of R454B refrigerant, the influence of low back pressure vortex compressor model line parameters on pump performance and axial gas force was studied from the perspectives of line equation, content product ratio, and suction and exhaust form. On the basis of the original algebraic spiral profile, an asymmetric suction profile based on the circular involute equation form was optimized. Through testing and verification, the new line improved the overall performance by about 1%~1.5% compared to the prototype line.

When paired with a wall mounted mechanism for thermal temperature control shutdown, there is heat leakage in the one to many air conditioners, which affects the accuracy of sensor temperature sensing and even causes the air conditioner to fail to start, thereby affecting the comfort of the room. To solve this problem, experimental research was conducted using the air enthalpy method to obtain the heat leakage of the standby hanging machine under different heating conditions and air flow rates. And on the basis of experimental research, various optimizations have been made to the operation mode of the fan after the machine reaches the temperature and shuts down, allowing different users in the global market to adjust the leakage heat of the machine during the machine heating and shuts down according to the actual situation of room insulation, enhancing user comfort.

Raises the minimum limit value of APF in accordance with GB 21454—2021 "Energy Efficiency Limits and Energy Efficiency Grades for Multi connected Air Conditioning (Heat Pump) Units" released by the National Standards Commission in 2021. Further research is needed on the influencing factors of multi connected APF and the methods for improving APF; Using a certain 16HP top-outlet air multi line, experimental tests were conducted to verify the impact of the size of the return oil capillary, the flow path of the outdoor heat exchanger, and the cycle time of low-temperature heating and defrosting on the APF. The experimental results showed that optimizing the flow path of the outdoor heat exchanger, the size of the return oil capillary, and the cycle time of low-temperature heating and defrosting is beneficial for improving the APF, with an increase ratio of 8.41%, 3.29%, and 1.68%, respectively; The main purpose of optimizing the size of the outdoor thermal exchange circuit and return oil capillary is to improve the energy efficiency ratio of the intermediate working conditions to achieve the goal of improving APF, while the main purpose of optimizing the cycle time of low-temperature heating and defrosting is to increase its circulating heat capacity and improve the overall APF.

Built a test platform using injection bypass of sub-cooler to study the influence of injection volume on heating thermodynamic characteristics. The test results show that as the injection volume gradually increases, the exhaust temperature of the compressor also decreases, which can ensure the stable operation of the unit in cold regions; when the outdoor temperature is lower than 0°C, the outlet temperature and inlet temperature of the auxiliary road are comparable, the heating capacity and energy efficiency of the unit are the largest, and as the injection amount increases further, the heating capacity and energy efficiency of the unit begin to decrease; when the outdoor temperature is higher than 0°C, when the injection amount is "0", the heating capacity and energy efficiency of the unit are the largest.

Compares the energy consumption of the air-source heat pump under different control logics.Mainly through two dimensions, one is the single-point COP test results, the other is the 24 h power consumption test results; based on the above two test results, the energy-saving control strategy of heating machine is obtained. The experimental results show that the power consumption of the unit can be reduced from 94. 9 kW·h to 79. 3 kW·h, which is 15. 6 kW·h, and the energy saving can be improved by 19.6% under the optimized control logic when the ambient temperature is -12℃ and the water temperature is set at 45℃ (return water temperature). Through the experiment, it can provide reference for the design of energy saving control strategy of air source heat pump. At the same time, the change of comfort (temperature field) is also compared.

Through comparative experiments, analyze the heat transfer performance, overall capacity and energy efficiency of all-aluminum microchannel heat exchangers and copper tube aluminum fin heat exchangers. The results indicate that the whole machine equipped with an all-aluminum heat exchanger has significant advantages in terms of capacity and energy efficiency, but its capacity decays severely under low-temperature heating conditions, the problem of uneven flow separation still needs further improvement.

Introduces the innovative principle of the double suction (DS) structure of a reciprocating compressor and its innovative solution applied to the refrigerators system. Firstly, a DS compressor structure with reciprocating piston controlled the opening and closing of the second suction port was innovatively designed. The working principle and characteristics of the compressor were detailed, as well as its application in a new refrigerator system with a gas-liquid separator. Secondly, theoretical analyzed the refrigeration performance of DS compressor and new refrigeration systems, such as refrigeration capacity, consumption power, and COP. Finally, the refrigerator performance was calculated using refrigeration system simulation software, such as the matching operation rules of the system and the performance improvement of DS refrigerator. The results show that the refrigeration capacity and COP of the new DS refrigerator have significantly improved, with the maximum being 16.1% and 8.2%, respectively. This means that the power consumption of refrigerator can be significantly reduced. In the future, the DS technology can provide system solutions of the super-efficient refrigerators for refrigerator manufacturers.

With the frequent occurrence of extreme weather worldwide, summer temperatures are getting higher and winter temperatures are getting lower, and outdoor temperatures are about to exceed human tolerance. In order to change extreme weather, China has focused on the dual carbon goal and vigorously advocated for low-carbon environmental protection. As an effective means of adjusting air temperature, air conditioners have become essential household appliances for every household. This article takes a 30 K four direction embedded air conditioner as an example to conduct multi-level optimization of the refrigerant type, condenser configuration, compressor displacement, and throttling element modules of the air conditioner, so that the air conditioner has relative advantages in terms of price and green low-carbon. Performance related tests are also conducted on the optimized air conditioner, the test results meet the ability and energy-saving standards.

By introducing the change law of temperature and humidity in the refrigerator, the physiological change process of fruit and vegetable, and the influence mechanism of fruit and vegetable storage quality under different temperature and humidity fluctuations. Select spinach and blueberries as the test object, in the refrigerator of different temperature and humidity and fluctuation, the water loss rate, rotten fruit rate, vitamin C content, sensory, the results show that: the packaging of fruits and vegetables in the refrigerator storage, temperature between 2~4℃, temperature fluctuation is less than ±0.5℃, relative humidity about 70%, can obtain good storage effect. The temperature and its fluctuation of the refrigerator storage space are strictly controlled, and the appropriate reduction of the average humidity is conducive to the long-term storage of packaged fruits and vegetables.

With the development of society and the improvement of living standards, occupants require a more comfortable indoor environment. The natural wind is significantly more preferred than the mechanical wind produced by conventional air conditioners due to its natural, fresh, soft, and variable blowing characteristics. By controlling the multi-stage and multi-period motion mode of the air conditioner fan plate, combined with the bending and twisting shape design, the wind speed disorder of the air conditioner is realized, and the wind speed fluctuation, wind speed distribution and turbulence can reach the level of outdoor natural wind. Finally, a more comfortable airflow is achieved, which has improved human comfort.

Humidity has great significance to people's living environment and working environment. Air conditioners or humidifiers with humidification function on the market generally do not control the related humidification factors, resulting in generally low humidification volume. In order to obtain a higher humidification amount, according to the evaporation formula of humidification amount, research analysis and design will be carried out from the three directions of wind temperature, water temperature and evaporation area to explore their influence degree on humidification amount. The experimental results show that the increase of air temperature, water temperature and evaporation area is conducive to the increase of humidification amount, and the water temperature has an obvious effect on the increase of humidification amount.

The twin air conditioning system utilizes branch pipe components for mechanical flow separation, and the length of branch pipes connecting each indoor unit has a significant impact on the capacity of the indoor unit in that circuit. In order to ensure uniform distribution of refrigerant in each indoor unit and equivalent capacity output, theoretical analysis was conducted on the impact of branch pipe length on capacity, and experimental verification was conducted. Finally, it is suggested that the length difference of the split manifold during actual installation should be controlled within 8 m to ensure the stable operation of the twin air conditioning system.

In order to improve the comfort of air apply for cooling and heating, of the air duct machine, as well as the impact of air volume, performance, and noise under two typical return air modes, and to distinguish it from existing centrifugal air duct machines with blowing, a suction type cross flow air duct machine has been studied and provided. Not only can it achieve advantages in box size and adapt to more installation scenarios, but it also has advantages in air supply comfort. The cooling air supply height is higher to avoid cold air blowing people, and the heating air supply height is lower, which can achieve early landing of warm air and warm feet with hot air. At the same time, two air inlet methods, rear return air and bottom return air, were simulated. While ensuring the width of the air inlet, the bottom return air has little impact on the air volume and cooling and heating effect, but the noise is relatively high.

Establishing a mathematical model of an oil separator can help designers evaluate its performance and optimize the design to achieve the best performance. The motion of oil droplets in the oil separator is analyzed, and a calculation model of oil separator efficiency based on residence time method is established in combination with the size distribution of droplets in the two-phase flow. At the same time, experimental tests are carried out to validate the model, and the deviation of the separation efficiency is not more than 5%.

R32 refrigerant is gradually favored by the refrigeration industry due to its ODP value of 0 and small GWP value. Currently, many enterprises in the industry are conducting research on the technology of R32 replacing R410A. In order to compare the differences between R410A and R32 refrigerant air conditioners, experimental studies were conducted on R32 refrigerant air conditioners and R410A refrigerant air conditioners. The results indicate that as the ambient temperature increases, the exhaust temperature of R32 refrigerant air conditioner significantly increases compared to R410A refrigerant air conditioner. Therefore, it is necessary to control the exhaust temperature of R32 refrigerant air conditioner. In order to find the optimal exhaust temperature control method for R32 refrigerant air conditioners, experimental studies were conducted on three exhaust temperature control methods in terms of performance and reliability. The final experimental results showed that using piston cutting main bearing spraying technology can significantly reduce the exhaust temperature of R32 refrigerant air conditioners while ensuring overall capacity and energy efficiency.

At present, the requirements for motor energy efficiency are becoming increasingly high, and efficient motors have become a hot research topic in various fields. Firstly, starting from the basic formula of motor efficiency, decomposes the formula, and then conducts root cause analysis on the key parameters that affect efficiency, thus proposing the efficiency improvement ideas for the studied motor. Then, taking an example of an air conditioning external rotor fan motor, based on the analysis results and combined with process manufacturing and noise parameters, an efficiency improvement analysis is conducted on it. Finally, sample preparation testing was conducted on the optimized plan to further verify the reliability of the theoretical analysis. The research results will provide effective guidance for the design and development of high-efficiency motors in the future.

The popularity of smart homes remains high, but sales are not satisfactory. Artificial Intelligence Generated Content (AIGC) empowers home furnishing to transform from intelligence to intelligent agents and biomimetics, more in line with the people's needs for intelligent and beautiful lives. Focuses on the biotransformation of smart home based on AIGC mechanism. It discusses the feasibility of smart home biotransformation, the construction of a biotransformation system, the technical support of AIGC for smart home biotransformation, and the multimodal perception of smart home. It provides the biology-like model of intelligent home appliance based on the AIGC mechanism for the home appliance industry transformation.

Study on the degradation effect of oxytetracycline on meat food during storage in refrigerator under different storage conditions and different degradation technologies. The research results show that the degradation rate of oxytetracycline under refrigeration temperature is better than that under micro freezing and freezing, and the degradation rate of oxytetracycline gradually increases with storage time at the same temperature. The degradation effects of different degradation technologies on oxytetracycline are as follows: ozone technology>photocatalytic technology>anion technology. Compared with ozone technology and negative ion technology, photocatalytic technology has a smaller sensory impact on meat products. This study has important reference significance for ensuring the dietary health of consumers.

The common European-style range hoods mainly include an inverted cone filter structure and a plane filter plus baffle structure on the market. The flow fields of these two European-style range hoods are numerically simulated and compared quantitatively, after computational fluid dynamics numerical simulation methods. It also analyzes the influence of different air inlet structure forms on the speed and pressure distribution of the range hood, as well as the pollutant trapping capacity, which provides a theoretical basis for the appearance performance evaluation of the air inlet of the range hood, and lays the foundation for the optimized design of the air inlet of the range hood. Comparing the three dimensions of speed, pressure distribution, and oil fume capture, the results show that there is no obvious difference between the speed and pressure field test values. The upper inverted cone filter structure air inlet is more conducive to smoke exhaust.

The practice and evaluation methods of steamed buns and the easy problems and quality analysis of steamed buns in steam ovens are presented in detail. The evaluation methods are mainly texture, specific volume, whiteness and dryness and humidity analysis of steamed bread crust. At the same time, the causes of problems such as wrinkling, blistering, cracking and yellowing of steamed bread are analyzed, and the fermentation and steaming functions of the steamer affect the quality of buns with a view to providing a theoretical basis for the evaluation of the fermentation performance and steaming performance of the steamer.

In the human-machine dialogue system, in order to understand the user query, should do intent classification and named entity recognition (NER), and NER can be thought the fine-grained information based on user intent. The difficulty for NER task is that the task includes two parts: entity type extraction and entity boundary extraction, and both parts need to be correctly identified. But in practical application scenarios, due to lack of domain knowledge, our model always fail on understanding user query. Work on music, radio, video, poetry and other related fields, and propose a method which adds entity type and entity boundary to Bert model. Experimental results demonstrate that our proposed model achieves 3% and 5% improvement on intent classification and NER by adding domain knowledge. Domain knowledge can help the model grab information, and improve the accuracy of the model, especially when lack of contextual information.

Introduces the flexible composite drive technology suitable for drum washing machines, and analyzes the structure support, washing and dehydration principles of the flexible composite drive technology. The specific method is to add a set of auxiliary power mixing device on the end face of the inner cylinder, and the direction of rotation of the agitator is opposite to that of the inner cylinder, so that the clothes washed in the inner cylinder under the action of the agitator produce a reverse reversal force and increase the washing effect. The key point is that the added set of auxiliary washing adopts a flexible drive. When the reaction force of the mixing device is greater than a certain torque, the auxiliary washing device will automatically stop rotating instead of being forced to drive, which effectively prevents the damage of the auxiliary washing device when it is subjected to large torque, and also effectively protects the clothes from being damaged by the forced washing torque. The technology can improve the washing ratio of the drum washing machine, and can wash clothes by cold water washing, at the same time, the flexible drive has overload protection function.

In order to study the effect of gas power and its distribution on cooking performance, shrimp was selected as the object of study, and sensory, cooking time, cooking weight loss and gas consumption were used as evaluation index. Results showed that: the sensory, cooking time, cooking weight loss and gas consumption between inner ring cooking and outer ring cooking at 5.7 kW have no significant difference (P>0.1); the sensory, cooking time, cooking weight loss and gas consumption of outer ring cooking at 6.2 kW are better than that of inner ring cooking at 6.2 kW; for inner ring cooking and outer ring cooking, the larger the gas power, the better sensory, the shorter cooking time, the less cooking weight loss; the gas consumption of outer ring cooking at different power has no significant difference (P>0.1); the gas consumption become larger when the gas power of inner ring cooking increases. And conducts such conclusion: based on current experimental condition, the cooking performance between inner ring cooking and outer ring cooking at 5.7 kW has no significant difference; the cooking performance at 6.2 kW is better than that of 5.7 kW; the larger the total gas power, the better cooking performance.

The key influencing factors on the heating recovery speed and hot water volume of two combined electric water heaters have been analyzed through research and experimental verification of different connection schemes. By optimizing the connection method and control program, the heating rate and effective heating time of the two electric water heaters can be increased, providing users with more hot water and improving their bathing comfort.

With the rapid development of the Internet of Things (IoT) and the smart home market, cross-ecosystem interaction has emerged as an urgent issue to be addressed in home appliance products. The devices and ecosystems in the smart home market are fragmented, and various barriers exist between ecosystems, hindering interconnectivity and interoperability. Users face numerous challenges in building a whole-house smart system and the need to download different ecological apps for devices of different brands leads to a poor user experience. To address this, the Matter protocol was introduced. A cross-ecosystem interactive air conditioner based on the Matter protocol was designed. Through interpreting the protocol, sorting out the certification process, developing hardware and software, and testing and verifying Matter's functions and performance. The final experiment shows that the Matter protocol holds significant advantages in cross-ecosystem interactions. The designed Matter protocol-based air conditioner truly realizes interconnectivity and communication between ecosystems, greatly improving the user experience, and providing an efficient and stable solution for the smart home industry. This research provides valuable references for further improvement and popularization of smart home product designs based on the Matter protocol, with minor text modifications.

The application of intelligent air conditioning is inseparable from high-performance human target detection algorithm, so it is necessary to improve the detection accuracy and positioning accuracy of infrared human target. First, YOLOv5 is improved, and SIOU loss function and CA attention mechanism are introduced respectively to improve the detection ability of the model. Secondly, according to the scene requirements of household air conditioning and the characteristics of infrared images, a set of targeted data enhancement method is designed to further optimize the training effect of the model. Finally, the improved model is applied to the actual scene recognition of the air conditioning prototype. The results show that the improved YOLOv5 model is superior to the traditional methods in human target detection accuracy and positioning accuracy, and has certain practical value.

There are a wide range of smart home products, with rich application scenarios and great imagination, which can bring consumers a beautiful life experience. However, affected by factors such as technology and business model, the interconnection problem of smart home restricts the development of the industry. At present, smart home interconnection is basically based on the two technologies of self-built ecology of head enterprises and cross-brand cloud interconnection. In particular, cross-brand cloud interconnection requires the integration of two or more user account systems. This "centralized" technical architecture solution brings difficulties to brand operation and poor user experience. The essence of smart home interconnection is still to cooperate with each other to complete a certain task in a smart life scenario. Conducting research on broadcast subscription technology, physical model, and technical application, etc., to achieve a minimalist solution for "decentralization" and interconnection between things, and provides a smart home local self-collaboration model based on broadcast subscription technology for local self-collaboration of smart homes, which realizes self-collaboration between smart homes in a minimalist way and improves user experience.

With the rapid popularization and development of the AIGC large AI model, unprecedented opportunities and challenges are brought to the field of smart home appliances, especially the washing machine industry. Focuse on the field of smart home appliances. It addresses many user experience issues encountered in the use of smart washing machines, such as increasing functions that leave users unsure about which mode is better to choose; intelligent voice interaction that only works with fixed phrases and commands, cannot handle an extra word, can't recognize accents, and doesn't understand colloquial expressions; device malfunction alarms make it difficult for users to identify the cause and can only wait for engineers to come, and other "pseudo-intelligent" problems. Therefore, takes full advantage of the AIGC large model in the household appliance vertical domain, and actively explores breakthrough paths to enhance the intelligent interactive experience of washing machines. The ultimate goal is to make the intelligent interaction experience of the washing machine better and smarter.

The air conditioning outlet grille is mainly used to protect the safety of users and cannot have a significant impact on the performance of the air conditioning. However, under heating conditions, the grid ribs will expand due to heat, causing the ribs to bend and deform, seriously affecting the appearance of the air conditioner, and also creating safety hazards. In response to this issue, a mathematical model of the grid under heating conditions was established, and the stability of the grid was analyzed. At the same time, various solutions to deformation problems were compared and analyzed, and the optimal solution was finally given. A universal formula for designing the grid was proposed. To verify the feasibility of the scheme, hand board experiments were conducted, and noise and air output were tested and compared. The results showed that the scheme is not only economical, but also can effectively solve the problem of grid deformation without affecting the performance of noise and air volume.

The solidification effect of UV 3 anti-glue in LED light was studied. By establishing a complete set of analytical verification methods, including the analysis of the solidification degree, the coating density the solidification energy research, the corrosion resistance can analyze, the electrical performance analysis, the analysis of the difference between the single band (365 nm) optical initiator and multi-band light initiator in the LED and mercury lamp light source. The application of led light solidification innovation technology is used in the field of electrical control protection, and the performance of the electrical control parts of electrical appliances can be improved effectively by experiment, and the failure rate of the electrical control parts is improved.

Aiming at the insulation tank components in the gas-electric hybrid gas water heater, a collaborative method of numerical simulation and experimental verification was used to study the influence of the volume design of the soaking tank on the start-up constant temperature and secondary start-up constant temperature performance. It was analyzed that in the first start-up scenario, the small volume soaking tank had a larger overshoot temperature and a faster heating rate. In the secondary startup scenario, the small volume soaking tank has a higher overshoot temperature, which takes longer to reach the constant temperature, providing a reference basis for the design of the soaking tank in gas water heater.

Vapor-liquid two phase flow is widely used in heat exchanger. Through the analysis of the heat transfer process and flow pattern of refrigerant in the tube, it is found that during the condensation process, the heat transfer coefficient in the tube is the highest when the liquid droplet is just generated, while during the evaporation process, the heat transfer coefficient in the annular flow is the highest. In order to achieve rapid liquid removal during the condensation process, a vapor-liquid separation technology that enhances heat transfer by thinning the liquid film has been proposed, which has attracted extensive research and application in recent years. Innovatively proposes a honeycomb vapor-liquid separation structure which can be applied to finned tube heat exchangers, simulation software is used to study the vapor-liquid separation process mechanism of the honeycomb separation structure. At the same time, the empirical formulas in Coildesigner are used to verify its accuracy and reliability, and the parameters of the honeycomb vapor-liquid separation structure are ultimately determined, which can achieve vapor-liquid separation efficiency of over 89%. At the same time, a finned tube heat exchanger equipped with a honeycomb gas-liquid separation structure can achieve a pressure drop loss reduction of 8.08% and a heat transfer increase of 6.22% compared to traditional finned tube heat exchangers.

The traditional axial flow fan for outdoor air conditioning units uses reinforced AS materials, which have the disadvantages of high density, high cost, and brittle and easily damaged materials. Takes the axial flow fan of outdoor units as the research object, and verifies the feasibility of lightweight and high stiffness PP material on the outdoor unit of air conditioning from the aspects of material mechanical properties, fan monomer performance, outdoor unit noise, air volume, etc. The results show that using lightweight and high stiffness PP material instead of reinforced AS material can reduce the weight of the axial flow fan by about 9.8%, and the performance indicators of the fan monomer and the entire machine meet the requirements of mass production.

The reasonable arrangement and addition of the annular suction plate on the range hood can improve the smoking effect. In order to study its impact on the internal and external flow fields, adding a annular suction plate to the air inlet of a range hood, the range hood is analyzed and optimized using CFD method for different annular suction plate sizes, different plate air inlet gap. Comparison between results of the calculation and experiment shows that the simulation model is credible. By comparing and analyzing the simulated 9 sets of data, it can be found that the annular suction plate has an influence on the internal flow of the fan, which has an influence on the fan flow rate, and has an influence on the fan efficiency, and also affects the flow state around the plate. Therefore, according to the flow field and the effect of the range hood, the suitable size range of the annular suction plate for the range hood can be determined.

Under limited installation space conditions, reducing the height of the casing is a convenient strategy to reduce the volume of the compressor, but reducing the height of the casing will worsen the OCR and pressure pulsation. To solve the problem, a CFD multiphase flow simulation model was used to simulate OCR and pressure pulsation. Analyzed the reasons for the deterioration of OCR and pressure pulsation, proposed to reduce OCR by increasing the wind resistance cover and reducing the initial oil level height, and completed simulation and experimental review. The reliability of the established CFD simulation method has been verified, and the research can provide theoretical and practical guidance for reducing compressor oil discharge rate and improving pressure pulsation.

After adding different proportions of n-butane (HC-R600) to the mixed component foaming system of cyclopentane (CP) and HFC-245fa, the performance changes of rigid polyurethane foams prepared in a mold and the variation laws of thermal conductivity (k-factor) and compressive strength under two different aging conditions with different aging time were studied. Then compare the above variations of k-factor with the changes under the natural aging in a refrigerator. The research showed that the fluidity was improved and the k-factor increased with the increasing contents of blowing agent R600, while the compressive strength remained stable. During different aging processes, the results of k-factor were similar, and the changes in compressive strength were inconsistent, but there were acceleration relationship between them. The changes in k-factor of the refrigerator were significantly less than the changes in mold foams within the same aging time under different aging conditions.

Due to the asymmetric structure of air gap of the single-phase permanent magnet brushless DC motor, coupled with the inevitable deviation of the concentricity processing between the rotor and shaft, it will bring rich harmonic content to the air gap magnetic density and radial electromagnetic force. Aiming at the problem of 11~20-fold frequency noise in the single-phase external rotor refrigerator fan, first derives the radial electromagnetic force of the permanent magnet motor in the uneccentric and eccentric state, and points out the radial electromagnetic force order and frequency under eccentric state. Secondly, it analyzes the influence of gradual air gap on the air gap flux density of the motor, and the influence of different surface magnetic curves on the air gap flux density and back EMF harmonic content, and the influence of different surface magnetization schemes on the radial electromagnetic force under the moving eccentric state is analyzed. The simulation results show that reasonable adjustment of the magnetization method and weakening the peak magnetic peak can effectively reduce the amplitude of the radial electromagnetic force. Finally, it is verified through experiments that the flat-top wavetable magnetic scheme can significantly improve the noise problem. The research results provide a reference for the design of the outer-rotor permanent magnet motor.

The acoustic performance of air conditioning insulation cotton has great significance to improve the sound quality of air conditioners. Its acoustic performance is mainly characterized by acoustic absorption coefficient and acoustic insulation quantity. Impedance tube based method is used to study the sound absorption and insulation performance of air conditioning sound insulation cotton material, to explore the relationship between its sound absorption and insulation performance and material configuration parameters, as a guide for the design of air conditioning equipment or selection of sound insulation cotton.

In order to solve the problem of high-frequency sharp noise during low-frequency operation of the compressor of air conditioning under heat-pump condition. Firstly, by identifying the vibration source, determine the mechanism of high-frequency sharp sound generation; Secondly, by modulating the carrier frequency, the improvement of sharp noise is achieved. Research has shown that sharp high-frequency noise is caused by the excitation of the compressor and fan by the carrier frequency, and the carrier frequency spectrum exhibits a significant octave relationship. For the compressor carrier frequency (5 kHz) and fan carrier frequency (15 kHz), the second harmonic of the compressor carrier frequency and the fundamental frequency of the fan carrier frequency have a significant contribution to sharp noise. Increasing the carrier frequency or modulating the compressor carrier frequency and fan carrier frequency in a staggered manner can effectively reduce sharp high-frequency sounds. The results of the research can provide a reference for suppressing high-frequency noise in motors.

The noise problem of the double bypass fans is analyzed in depth, and the source of the noise is diagnosed by modal analysis theory, it is found that the third mode resonance of the motor mounting plate causes the fan abnormal sound, the optimized design of the fan mounting plate structure is carried out by combining with modal simulation analysis. Finally, the optimized fan system is tested, which shows that the vibration noise of the optimized double bypass fans is eliminated, and the sound quality of the cascade fan is greatly improved. The method of noise source diagnosis and noise elimination based on modal theory can provide some guidance for the noise problems of the same type of products.

After the fresh air conditioner is installed, when the air conditioner is shut down, when the outdoor wind speed is higher than 6 m/s, there may be a loud noise in the indoor air conditioner, which affects the normal rest of the user. In order to improve the comfort of the air conditioner and enhance user satisfaction, through the analysis of the sealing structure and noise excitation source of the whole fresh air system, it is found that when there is a strong wind outside, the wind will pour into the fresh air pipe, and the wind will impact the inner wall of the fresh air pipe in the process of high velocity to produce noise, and the sound will be transported through the fresh air pipe into the cavity inside the fresh air module of the air conditioner. Thus producing backflow noise on the indoor side. In order to optimize the noise scheme of fresh air backfilling, it is proposed to design a circular muffler hole on the fresh air pipe, and the noise reduction effect is obvious.

The metal shell of the variable frequency outdoor unit is the main noise radiation source of the outdoor unit at certain frequencies under the excitation of the compressor. Using a half power band method, the damping of the original sheet metal structure and the sheet metal structure with added damping layer was compared. The damping was increased from 0.43% to 2.60%, and the sheet metal structure with added damping layer was applied to the outdoor unit casing. The peak noise was reduced by 12.8 dB(A), significantly improving the noise quality of the outdoor unit.

Consumers demand for textiles such as electric blankets has gradually shifted from visual requirements such as beautiful colors and novel styles to comfort and hommization. The demand for comfort of electric blankets is becoming increasingly high. Contact comfort is the main way to evaluate the comfort of textiles such as electric blankets, and objective testing of the tactile comfort of electric blankets is particularly important. Review The methods of evaluating the contact comfort of textiles in the industry are reviewed from the aspects of heat transfer characteristics, bending and torsion characteristics, surface friction characteristics, and compression characteristics. Due to the wide variety of textiles and the complexity and difficulty in quantifying the evaluation of tactile comfort, the evaluation of tactile comfort of electric blankets is a field that requires continuous research.

In order to launch new air conditioners that better meet user needs, user demand elements were explored through household interviews, questionnaire surveys, and other methods. Priority ranking was conducted on user demand elements, and it was found that users expect improvement in areas such as quietness, intelligence, comfort, and service. Priority needs to be given to reducing the noise during the operation of the fresh air function, improving the level of intelligent detection and interaction, and improving the level of professional installation services. By conducting user research to explore user needs, it can improve user satisfaction, enhance product market competitiveness, and provide strategic support for the subsequent development of fresh air conditioning.

Because some needle flame test devices adopt the method of extinguishing the flame at the moment when the flame application time reaches, this method is affected by the electromagnetic valve, which has a serious impact on the test results. In this paper, the causes of the impact are analyzed, the concept of ignition time is put forward, and a sample that can identify the sub-species risk is put forward. The laboratory can use the characteristics of this sample to identify the needle flame test devices with such risks, so as to avoid the testing risks.

T/CNLIC 0070-2022 ‘Household refrigerator-Test method and evaluation requirements for vacuum preservation’ has been issued and implementation on December 30, 2022 by China National Light Industry Council, clarifying the evaluation requirements and test methods for vacuum preservation technology of household refrigerators. Providing an interpretation from four aspects: the background of standard development, the basic situation of formulation, the main content of the standard, and technical verification, which is conducive to the promotion and application of the standard, while providing ideas for the refrigerator related standards revision, promote the development of industry norms.

The cooling (heating) capacity and energy efficiency of air conditioning heat pump devices are the main indicators for evaluating their performance. In laboratory steady-state performance measurement, in order to reflect the improvement of partial load performance of air conditioning heat pumps, performance evaluation has gone through a process from "point" evaluation to seasonal performance evaluation, but its essence is the steady-state operating parameters under given heat source side and usage side conditions, as well as specified compressor and fan operating conditions. With the development of the control level of air conditioning and heat pump devices, in order to further improve the automatic control characteristics and quality control of air conditioning and heat pump devices, reviews the methods for measuring performance based on variable loads at home and abroad, including static compensation method (chamber induced load) and dynamic compensation method (virtual building load). Essentially, virtual air conditioning heat and humidity load is applied to the inside of the laboratory room, And it is required that the air conditioning and heat pump device use automatic control technology to adjust the indoor temperature to the set temperature based on the indoor load, in order to obtain the performance of the unit during this period. Aims to provide reference or basis for establishing a measurement scheme for simulating the actual operating performance of air conditioning heat pump devices in the laboratory.

The function of an air conditioner is to meet the user's comfort requirements for the indoor environment by adjusting the indoor temperature and humidity to meet the set standards. At present, there is a significant deviation in the temperature sensor detection value of the one to many air conditioners on the market, which leads to some indoor unit automatically turning off when the hot running temperature reaches the desired temperature. After the room temperature drops, the air conditioner cannot start, reducing user comfort. Conducts in-depth research on this issue, analyzes the reasons for environmental temperature detection deviation, proposes improvement measures for sensor installation position, and conducts experimental verification. The results indicate that the sensor located on the right side of the air conditioner far from the coil can reduce interference in temperature detection, and the air conditioner can start normally after the room temperature drops, improving user comfort.

Aimed at the problem of high temperature at the top of the refrigeration chamber in a two door air-cooled refrigerator with a hidden and hidden mechanical air door. By establishing a simulation of the overall flow field and temperature field, and analyzing the structural characteristics of the air duct and refrigerator, the reason for the high top temperature is determined, and an optimization plan is proposed for improvement. It is hoped that the problem can be improved through air duct optimization. Through multi-dimensional testing and verification, the optimization scheme has significantly improved the top temperature, providing a reference for future design optimization of such refrigerators.

Cross-flow fan is the core air supply component of cross-flow air conditioner, and its structural performance directly affects the reliability of the whole air conditioner. Therefore, it is necessary to study the strength and fatigue life analysis of cross-flow fan of cabinet machine. The finite element model of single-section cross-flow fans with different fan blade lengths were established, and the static strength of cross-flow fans were obtained by finite element analysis method. Based on this, Abaqus/Fe-safe software was applied, based on the S-N curve of materials and the Goodman average stress correction method was used to predict the fatigue life of cross-flow fans, and the influence of the blade length of cross-flow fans on the structural strength and fatigue life of the fan was summarized. It is known that the comprehensive performance is better when the single blade length is about 60 mm. At the same time, the fatigue life analysis method can save a lot of experimental time and cost of cross-flow fans, which provides an effective reference for engineering design.

The radiant heating system brings excellent thermal comfort but consumes much energy. How to ensure comfort while reducing the operating energy consumption has become an important issue. By building a simulation platform for home air conditioning radiation system, studies the comfort and energy consumption performance of different operation control strategies, and finds some rules. Firstly, a modular system simulation platform was built, and calibration and verification were carried out based on experiments. Based on the system simulation platform, the comfort and energy consumption characteristics of different control strategies were studied. Under intermittent operating conditions, the air conditioning and radiant floor double-on strategy can ensure better energy saving without reducing thermal comfort when people are at home, compared with the traditional constant water temperature control strategy. The typical daily energy saving is up to 35%. The longer the interval, the higher energy saving is observed. The energy saving rate may be affected by the outdoor working conditions when the unit is turned on. The results can be used to guide the control design and optimization of home air conditioning floor heating systems.

Heat pump air conditioners have a high popularity rate due to their ability to cool in summer and heat in winter, which puts forward higher requirements for the comfort of air conditioning. Frosting under rated heating conditions is a common occurrence in most air conditioners, and frequent frosting and defrosting under such conditions can easily cause customer complaints. By analyzing the frost formation mechanism of outdoor heat exchangers and combining experimental research, the problem of frost formation in outdoor heat exchangers under rated heating conditions is solved by adjusting the refrigerant flow rate of the system and the heat exchange air volume of the internal and external units.

Uses ANSYS and acoustic simulation software to simulate the flow and sound fields of the cylinder head components of a certain type of inverter compressor, optimize the cylinder head structure to reduce noise, and process samples for experimental testing. Research shows that the new cylinder head has a maximum decrease of 9.12% in dynamic pressure, 4.58% in flow rate, and 18.24% in turbulence intensity compared to the original cylinder head. There is no peak at the second channel position. The simulation of aerodynamic noise and the simulation of radiated sound field show varying degrees of decrease in sound pressure levels at various monitoring points in the full frequency band. Comparing the experimental noise tests of the compressor, it is found that the noise of the new cylinder head decreased significantly at full speed, with the maximum decrease being a 6.1% decrease at 3900 r/min. Through spectrum analysis, it is found that the sound pressure level in the 4000~5000 Hz frequency band decreased, resulting in a decrease in noise.

When the fresh air conditioner uses the exhaust ventilation function in a low temperature environment, it is easy to cause condensation icing and blockage in the exhaust duct, which affects the ventilation effect and service reliability. Therefore, it is of great significance to study the improvement and prevention of condensation icing in the exhaust duct. Based on the formation principle of condensation and icing in exhaust pipe, a set of operation prevention and control logic is proposed to predict the risk degree of condensation and icing through the calculation and comparative analysis of the temperature of exhaust pipe inner wall. Experimental verification shows that only a small amount of condensation and icing are produced in the exhaust duct during the outdoor -7℃ exhaust function test for 8 h, and the reliability is significantly improved.

The vibration reduction design of air conditioning compressor piping is an important part of the research and development process. Traditional suction pipeline design often achieves vibration reduction by adding bends around the compressor. In order to optimize the suction pipeline, a new type of suction pipeline was designed to be used with a pipeline vibration absorber, which can significantly reduce the difficulty of pipeline processing and material costs. And through HyperMesh finite element simulation combined with experiments, it has been proven that the vibration of the new pipeline is better than that of the traditional suction pipeline. After parameter optimization, the vibration absorber reduced the pipeline amplitude by 77.5% more than the shock absorber.

In response to the phenomenon of frost formation in the evaporator inside the air conditioner, a profound analysis is conducted on the causes of different faults, and three different solutions are proposed based on the characteristics of the refrigeration system and temperature control principles. Through experimental comparison and verification, simulate the operating conditions of air conditioning in actual environments, compare and analyze the improvement procedures for evaporator frost, and finally use the method of optimizing the operating parameters of the refrigeration system to optimize the problem of evaporator frost. This solution solves the problem of uneven distribution of refrigerant in the evaporator, causing the outlet temperature of the branch to be too low, leading to frost formation in the internal evaporator. It significantly improves the cooling effect and user experience of the air conditioner. Hope it can provide some reference for improving the frost formation problem of air conditioner evaporators in the future.

When the heating function of air conditioner is turned on, especially in low temperature and high humidity, the outdoor condenser of air conditioner is easy to frost by ice. The effect of defrosting, the noise and the impact of defrosting of the heating ability have a great impact on the user experience. Especially in the case of low temperature and high humidity in the south, frost formation is serious. It is difficult to remove and affects the heating ability, affecting the user's heating experience. Optimizes the defrosting control logic of air conditioner in low temperature and high humidity environment. Through the outdoor coil temperature and outdoor ambient temperature, the frosting degree is intelligently judged. The defrosting effect of air conditioner outdoor heat exchanger in low temperature and high humidity condition is improved. The system can make intelligent judgment and timely defrosting, improve the heating effect under the same working conditions, and realize the significant improvement of user experience in heating. The action of electronic expansion valve and four-way valve in defrosting is optimized, which reduces the noise of defrosting.

With the development of preservation technology, the preservation ability of refrigerators is constantly improved, which basically meets the needs of consumers for the preservation performance of refrigerators. However, due to the storage temperature (–18℃~–24℃) is difficult to achieve rapid cooling of food materials, the refrigerator freezing preservation ability still has large weakness. In order to improve the freezing preservation effect of the refrigerator, the freezing temperature of the test solution, the cooling plate and the air as the heat exchange medium were used as the evaluation indexes to judge the freezing preservation effect. The experimental results show that: at the temperature of –24℃, pure water was treated with 66% glycerol solution as heat transfer medium, obviously overcooling, and the overcooling degree reached 6.6℃; the formation time of the experimental package with 66% glycerol solution was shortened by nearly 59.3% and 106.3% compared with the samples in air and the cooling plate, respectively. Theoretical analysis of the larger supercooling degree and more rapid passage through the maximum ice crystal belt is conducive to food to produce more and smaller crystal core, and reduce the damage to food quality. Since the test package is an experimental auxiliary material that simulates the material properties of beef, the test results can reflect the actual storage effect of the food ingredients to a large extent.

Compressor liquid hammer fault is a key issue that restricts the application of hot gas bypass defrosting technology in household cold products. In order to study the impact of different compressor anti liquid hammer schemes on defrosting performance, two schemes were designed, namely the gas-liquid separation scheme with a liquid reservoir and the compressor self protection scheme, to verify the power consumption, defrosting speed, heat utilization rate, room temperature rise, and other aspects. Verification shows that the self protection design of the compressor has higher defrosting power, higher mass flow rate, and shorter defrosting time compared to the anti liquid hammer method of the reservoir, the defrosting section saves about 8% of power consumption, and the room temperature rebound presents disadvantages, the maximum temperature difference between single point and no-load is about 6℃.

Most of the indoor side of window air conditioners use centrifugal blades to supply air, and the air duct structure leads to the current noise of more than 60 dB. In order to improve the user experience, the new generation of silent window air conditioners mostly adopts cross-flow fan systems on the indoor side. In order to study the influence of the cross-flow fan system on the air volume and noise of the window air conditioner, in view of the problems of low air volume and high noise of the existing window air conditioner, the performance of the fan system is improved by studying the cross-flow fan system, so as to improve the air volume, reduce noise and improve the comfort of the window air conditioner. By optimizing the layout of the air duct inlet and outlet and the resistance of the runner, the size and blade shape of the through-flow blade are optimized to match the system of the whole machine to achieve the purpose of improving the air volume. The experimental results show that the reasonable air duct end layout and the change of the worm tongue to increase the diameter of the blade increase the air volume of the cabinet machine significantly.

With the upgrading of consumption, people gradually consider comfort as one of the important criteria for purchasing air conditioners. The cooling and heating effect is an important indicator for evaluating the comfort of air conditioning, when users evaluate comfort, temperature is the primary and intuitive feeling. The research optimizes the starting logic of the air conditioning compressor to improve the outlet temperature of heating and cooling, thereby enhancing the cooling and heating effect and comfort of household air conditioners. Mainly focuses on optimizing the outlet temperature in terms of compressor startup logic, that is, starting from the compressor startup time to achieve the optimization goal, thereby improving the cooling and heating effect and comfort of the air conditioner. By comparing the air outlet temperature, compressor startup time, and fan startup time of two different brands of household cabinets and the same cabinet before and after the change, it is confirmed that shortening the interval between compressor and fan startup can increase the air outlet temperature by 1℃~2℃. During this process, it is necessary to pay attention to whether the pressure during the start of the air conditioner exceeds the standard. At the same time, verify the start-up reliability of the air conditioner under different operating conditions.

After long-term operation in the dusty environment, the surface and gap of the bottom condenser fins are easy to accumulate dust, and the dust accumulation increases the air flow resistance and the heat transfer resistance of the condenser, which ultimately affects the operation performance of the refrigerator. The influence of dust accumulation of condenser on the operation performance of the refrigerator is studied through the test. The results show that the energy consumption of the refrigerator increases by about 3.6% after dust accumulation, the minimum temperature that can be maintained in the freezing chamber increases by 1℃ when the ambient temperature is 43℃, the temperature pulling speed does not change at 32℃. The refrigerator runs well after the bottom condenser is completely dust accumulation.

Conducting research on the fracture problem of parking air conditioning pipes, taking the pipes system as the research object, building a finite element simulation model, conducting modal analysis and unit frequency response analysis, loading the enterprise standard random vibration PSD power spectral density, conducting random vibration simulation analysis, and obtaining fatigue damage results of the piping system. The simulated fatigue fracture position of the original pipes is consistent with the random vibration test, verifying the accuracy of the simulation model. By changing the length of the rubber pipes on the suction pipe, the optimized fatigue life of the pipes was significantly improved, and the pipes did not break after random vibration testing. Provides guidance for fatigue analysis and optimization design of air conditioning pipes, shortens the project development cycle, and reduces design costs.

In order to more clearly clarify the development status of built-in refrigerators, meet the user's ultimate compression of residential space, and pay attention to the huge demand of users for refrigerator aesthetic upgrades. Through literature and patent industry reports and other data review, the mainstream design scheme and brand selling points of embedded refrigerators are analyzed, the current status of the industry and relevant industry standard requirements are summarized, and the popular research fields of embedded refrigerators are summarized. Aiming at the problems encountered by built-in refrigerators, such as low degree of embedding, door opening interference, and poor heat dissipation of refrigerators, some of the latest research methods and solutions are summarized. Provide more reference directions for the subsequent development and design research of the embedded refrigerator industry.

With the increasing popularity of air conditioning in daily life, the concept of healthy air conditioning is gradually gaining popularity. In ordinary air conditioning, there are inevitable problems such as bacteria, viruses, and dust accumulation on the evaporator surface during use. Based on this, air conditioning units with high-temperature sterilization and self-cleaning functions in the interior unit are increasingly favored by consumers. Proposing an optimal control scheme to further optimize the self-cleaning effect of self-cleaning air conditioning units by changing the setting values of relevant parameters during the operation of the self-cleaning function under rated and high humidity conditions. During this process, synchronously monitor parameters such as drainage at each stage of self-cleaning, system exhaust, and compare the optimization effects of different setting values on the self-cleaning function. This was then analyzed and demonstrated through experimental results.

The inverted air duct machine adopts the suction system scheme. The condensation problem inside the box has become the key problem in the air conditioning design. The causes and solutions of condensation problems in the air conditioning box were analyzed. Firstly, the main mechanism of condensation formation was determined by analyzing the location and phenomenon of condensation. The temperature field inside the chamber was tested in the experiment, and it was determined that there was a problem of uneven shunt in the design of heat exchanger, which led to uneven heat transfer and the presence of hot and humid air, which became the main factor leading to condensation. Then the CFD simulation technology was used to simulate the internal flow field, and it was confirmed that there was eddy current at the bottom of the volute, and the hot and humid gas converged at the bottom of the volute to form condensation. According to the flow field in the machine, the air guide plate is formulated to alleviate the temperature field stratification phenomenon caused by the uneven heat transfer under the influence of shunt and gravity. The feasibility of the scheme is further verified through experiments, and the problem of condensation inside the box is finally solved, and it is applied to the product.

An active energy saving method for household air conditioners based on the L-M algorithm is proposed. By obtaining operating data of the air conditioner, the time required for the indoor temperature to reach the set temperature is predicted in real-time, combined with the cooling rate, the operating frequency of the compressor is controlled, and the operating curve is continuously optimized to achieve the goal of more energy saving and more comfortable use. The most energy-efficient operating path with reducing work on latent heat, and reducing damping, which is combined with PID control, the indoor temperature control is more stable and smoother to reach the set temperature to reduce the increase in useless energy consumption caused by temperature fluctuations. The test results show that the algorithm has an energy saving rate of nearly 25% in certain environments, and the energy saving effect is good.

Because the lack of air conditioning installation positions in general commercial kitchens and the special cooking environment in the kitchen, when residents use kitchen air conditioners, they generally encounter problems such as the lack of installation space for internal and external units, and the significant impact of kitchen oil fumes on the cooling effect and service life of kitchen air conditioners. Inorder to solving the above problems, an integrated kitchen air conditioning system and its application compressor were studied. The compressor used in this system adopts a horizontal compressor, and the system is designed flat based on the height of the two compressors and the compressor. The system is installed inside the kitchen ceiling during practical application, which effectively solves the installation problem. The system adopts external air intake to ensure that no oil fumes are inhaled during operation. The compressor is optimized for vibration and noise reduction, and the rubber pad is made of oil smoke resistant material. The overall system has low noise and vibration, and good reliability.

The traditional multi-split air conditioning system performs simultaneous temperature and humidity treatment on indoor air, reducing room temperature while dealing with a large amount of moisture load, resulting in poor comfort and high energy consumption. In order to balance fast comfort and energy-saving effects, a high sensible heat refrigeration control algorithm for multi-split air conditioning systems was designed. Through experiments, the performance of the unit and indoor environmental temperature under ordinary refrigeration mode and high sensible heat refrigeration mode were studied. The results showed that, under the condition of ensuring the refrigeration capacity of the unit, the high sensible heat refrigeration control has higher refrigeration energy efficiency than the ordinary refrigeration operation control, and can effectively increase the temperature of the cold air blown out, improving energy efficiency while enhancing user comfort.

Designed a self-cleaning flock collection module to address the issue of front-loading washing machines lacking a flock reduction function and user complaints caused by the manual disassembly and cleaning of traditional flock filters. A flock filter and baffle with an elastic structure were installed in the lifting ribs of the drum. After collecting flocks on the filter, the centrifugal force during the dehydration stage can be used to shake off the elastic baffle, allowing the flocks to be discharged from the collection module, achieving flock collection and self-cleaning. The research also verified the installation position and pore opening schemes on the drum through simulation, and the results showed that the optimized overall structure will not decrease the mechanical strength of the drum. Remarkable flock removal efficiency was achieved through condition optimization experiments (flock collection rate reached 75.80% and residue rate as low as 0.32%). The research fills the gap in the field of drum washing machines where there is no flock collection technology and provides a feasible way to enrich user experiences using front-loading washing machines.

With the continuous development of LED technology, deep ultraviolet LED has been mature in various industries, and the electronics industry is studying the application of 365 nm band LED light source to replace mercury lamp in UV-curable three-proof adhesive. Due to the need for large curing energy, and to meet the needs of fast production and miniaturization of structure, it is often necessary to choose large radiant flux lamp beads and high density lamp bead layout design. Therefore, when designing LED light sources, in order to ensure the stability of long-term work, it is necessary to consider the use of appropriate heat dissipation methods. Uses ANSYS simulation software to evaluate the heat dissipation mode of 365 nm LED light source, and realizes the long-term reliability operation of 365 nm LED light source by designing a water-cooled heat dissipation module.

Capacitive touch keys are widely used in display panel touch control system of household appliances for their advantages of high accuracy and durability. As the first step of human-computer interaction, the sensitivity and reliability evaluation of touch keys is very important. In order to study the influence of circuit board level structure on touch sensitivity and reliability, based on the principle of capacitive touch, the change of touch effect caused by the difference of metal medium in the top layer (only copper plating and tin plating on the copper surface) was discussed. Finally, through the verification and comparison of different media schemes, it is found that the copper plating scheme has better performance in data sensitivity and stability. Through 8 mm and 3 mm copper rod tests, the frequency of z-value>6 in copper plating scheme is about 65.2%, which is higher than that in copper tin plating scheme (28.8%). Through z -value analysis, it can guide the design and manufacture of touch keys.

In order to solve the problem of hail impact resistance of the RV air conditioner top cover, a finite element model of the RV air conditioner top cover and hail is established, and the finite element method for simulating hail impact is feasible and the results are reliable. By using LS-DYNA software, considering the impact of driving speed of the RV, the speed of hail, the mechanical properties of hail and the cover, and through simulation analysis, the response at different impact point positions is given. The maximum stress appeared in the impact point area, the maximum stress at the impact point at two impact positions and two vehicle speeds is 21.02 MPa, which is less than the yield strength, the RV air conditioner top cover is safe and meets the design requirements.

Due to the release of volatile organic compounds from refrigerator materials and the odor generated by food stored in refrigerators because of their own metabolism or microbial effects, reducing and eliminating odors has always been a research focus for various refrigerator manufacturers. By reviewed some odor removal functional materials currently reported, and classified them from physical, chemical, and antibacterial odor removal materials. It analyzes the odor removal mechanisms and application status of different odor removal materials. Provide reference and reference for the development and application of the refrigerator odor removal module in the future.

With the large application of patch resistance on the PCB board of home appliances, the adverse occurrence of patch resistance also increase. In the age of metal film pin resistance, the poor resistance is mainly manifested as burning, rust, larger resistance value, and one of the bad resistance phenomena of the patch is the smaller resistance value. Through the environmental reliability test of PCB board, induce the PCB failure, lock the patch resistance through electrical performance analysis, and then observe the resistance structure, analyze the patch resistance internal silver element migration in the electric temperature and humidity environment, resulting in the decrease of resistance value.

Inspired by microstructure characteristics of lotus leaves surfaces, the biomimetic hydrophobic Ni coating has been fabricated by brush plating technique. The effect of the plating voltage on the morphology and wettability were studied. The surface morphology, chemical composition, and wettability of the Ni coating were obtain by means of ultra-depth three-dimensional scanning system, scanning electronic microscope (SEM), energy-dispersive spectroscopy (EDS), and water contact angle measurement. The result indicated that the as-prepared Ni coating exhibit typical hierarchical structure, which is similar to the morphology of lotus leaf. The evolution of surface morphology on the as-prepared Ni coating depends strongly on the plating voltage. The combination of the porous morphology and hierarchical structures plays a crucial role in improving the hydrophobic property. In absence of surface chemical modification, the wettability property of the Ni coating was transformed from hydrophilicity to excellent hydrophobicity (water contact angle 146°). The work also illustrated the relationship between the wettability property and the surface morphology by Cassie-Baxier model, which indicate that the biomimetic structure which like lotus leaf endows the Ni coating an excellent wettability property.

In order to solve the corrosion resistance problem of air conditioning evaporators in special environments, by analyzing the physical characteristics and chemical composition of oxygen free copper (TU2) and high phosphorus copper (TP2), and compares the refrigeration and heating performance of oxygen free copper evaporators and high phosphorus copper evaporators by experimental study. The results indicate that the physical properties of oxygen free copper are similar to those of high phosphorus copper, and its processing and welding properties are the same. The oxygen content in oxygen free copper is low, and its corrosion resistance is high. In the performance test, the machine installed with oxygen free copper evaporator has higher capacity and energy efficiency than high phosphorus copper evaporator. Therefore, replacing high phosphorus copper with oxygen free copper not only improves the corrosion resistance of copper pipes, but also has good heat transfer performance, proving the feasibility of replacing high phosphorus copper with oxygen free copper.

Aiming at the defects of weld marks generated on the surface of a large-scale and complex-structured dark-colored matte plastic product during injection molding, mold flow software is utilized to optimize the number of mold gates and the arrangement mode to make the weld marks converge on a narrow plane and a non-dominant plane, the influence of weld marks on the appearance of the products was further studied in the aspects of mold structure and material flowability, and high quality products were successfully obtained. Provide reference for the application of spray free technology to large and complex structural injection molded parts.

Glass surface cracking during gas stove transportation has a poor impact on the user experience, which will directly lead to the user's return and replacement, and will also have an adverse impact on the reputation of the enterprise. In order to study the causes of the glass surface cracking and summarize the improvement methods, the location and occurrence conditions of the glass surface cracking during gas stove transportation were studied, and the packaging foam scheme of the gas stove was optimized based on simulation analysis. Through the transportation simulation test before and after optimization, it is proved that the optimized scheme has excellent protection effect. The results show that the impact resistance of the optimized foam bottom pad can be increased by 4 times compared with that before optimization, which has a reference value for the subsequent research on the improvements of the glass surface cracking problem during gas stove transportation.

Based on the bubble defects of transparent injection molding products, the analysis, simulation and verification were carried out in combination with specific products in combination with the types of defects, the causes of formation, the optimization direction, the optimization measures, and the improvement effect. From the four dimensions of product, material, mold and injection molding process, certain bubble defect improvement measures were obtained, and certain technical accumulation was carried out for the subsequent design and development of such products.

Mainly through a research on the corrosion resistance and processing technology of air conditioner outdoor chassis, which is made of galvanized aluminum magnesium steel plate, so that it provides enough theoretical support for its application on air conditioner outdoor chassis. The research results indicate that galvanized zinc aluminum magnesium stell plate is better at corrosion resistance and self-lubrication than normal stell plate. By riveting, it can be used directly for air conditioner outdoor chassis without spraying.

The pulsator washing machine drives the flow of water in the bucket through the forward and reverse action of the pulsator, forming a certain regular water flow. The structure of the pulsator has a great influence on the strength of the water flow, so how to design a pulsator structure with outstanding performance has become a major priority of the pulsator washing products. Taking the powerful pulsator as the research object, the working principle, washing system and parameter setting of the pulsator were introduced, and the limited modeling and water flow simulation analysis of the pulsator were carried out by using Realflow simulation software, so that a pulsator structure with the best characteristics was obtained. The CFD method of water flow simulation can greatly reduce the invalid design and shorten the design cycle, so as to provide references to the water flow design of the pulsator type washing machine.

To solve the existing problem of bearing fretting wear in transported motor with packaging, and to clarify the mechanism of fretting wear generation, conduct theoretical verification tests based on Hertz contact theory. The verification results show that the bearing fretting wear requires a certain normal load and relative sliding in the tangential direction. When she motor is placed in A way, the vibration response value of the packing paper pad has the greatest influence on the magnitude of the normal load. When the acceleration response amplitude of the packing paper pad is lower than (x-1.1)g, the normal load is not enough to cause the occurrence of micro-motion wear, and the acceleration response amplitude of the paper pad (x-1.1)g is the critical value of fretting wear. Motor shaft B way placement and motor shaft binding can suppress the normal load required for fretting wear and relative sliding in the tangential direction, respectively, thus suppressing the occurrence of fretting wear. Using the power spectral density curve of the actual transportation process as the simulation input, establish the random vibration simulation model of the actual transportation process.

In order to solve the pain points of high temperature rising of IGBT and bridge rectifier, and large size of heatsink in 3 HP RAC, this paper proposed totem pole PFC with hybrid IGBT IKZA50N65RH5 as switch for high frequency leg, and built its CCM mode simulation model with average current control algorithm by PLECS, then got the highest efficiency 97.924% on 3.3 kW totem pole PFC evaluation board, and the switching frequency of IGBT was 65 kHz. It is helpful to decrease temperature rising of IGBT, improve system reliability.

The fumes generated during the cooking process can cause kitchen air pollution, posing risks to our health. Enhancing the smoke-extraction efficiency of the range hood contributes to creating a healthy and safe cooking environment, as well as improving the overall cooking experience. The design of the air intake form for range hoods has an important impact on the smoke extraction efficiency of the range hood. By analyzing the shortcomings of existing air intake forms for a range hood model and proposes an induced-draft and speed-boosting air intake form that combines the principles of fluid continuity, Bernoulli's principle, and the meteorological principle of through-flow wind. Theoretical analysis shows that designing an induced-draft air intake near the smoke exhaust port of the range hood can change the oil fume path and improve the smoke extraction efficiency.

With the gradual development of e-commerce, retail self-service terminals (hereinafter referred to as self-service terminals) gradually appear in commercial application scenarios. However, the existing communication modules of self-service terminals have problems such as high cost, limited use occasions, low data security, etc. Their communication modes are mostly 4G or 5G networking modes, with high charges, large power consumption, and high comprehensive costs. Nowadays, NFC (Near Field Communication) mobile phones have been popularized, and networking communication methods such as "touch and touch" have become a low-cost and efficient way for equipment to transmit information. In view of the above situation, a data interaction scheme for retail self-service terminals based on NFC technology was developed, and explored a low-cost and high security IoT solution for retail self-service terminals.

Due to the pressure of market competition and other reasons, the air volume of the range hood is getting larger and larger, and the noise problem is becoming increasingly severe, and it is difficult to make breakthrough progress on the noise reduction effect through traditional technologies such as structural optimization. Under the background of the rapid development of intelligent technology, the use of intelligent monitoring perception and logical control, intelligent technology not only improves the convenience and comfort of the range hood, but actually has significant effect on in-depth noise reduction. Select the most intelligent function of the intelligent range hood, and deeply study and demonstrate the noise reduction effect under the intelligent function from the perspective of reducing the time proportion of the high noise area.

In response to the problem of temperature difference between start and stop of gas water heaters, analyzes the working principle and the mechanism of the temperature difference between start and stop, and proposes technical solutions for ignition reaction time, shutdown reaction time, inlet and outlet water flow rate, inlet and outlet water temperature difference, and adding buffered start and stop temperature difference components to reduce the impact of temperature fluctuations on start and stop. Combine theory with whole machine testing to complete the validation of multiple factors and single variables. The experimental results show that shortening the reaction time of ignition and shutdown, reducing the inlet and outlet water flow rate, and the temperature difference between inlet and outlet, equipped with bypass pipes and constant temperature chambers, can effectively reduce the fluctuation range of start stop temperature, reduce the discomfort of sudden cold and hot water temperature, and improve the user's bathing comfort experience.

In view of the current problems of discrete manufacturing enterprises, such as multiple product categories, unstable order scheduling, more work in process and poor team atmosphere, the paper creatively proposes the use of value stream, dynamic programming, and efficiency to study and solve the problem. Firstly, divide the product family and draw a current value stream map to analyze the current problems of insufficient production scheduling, poor efficiency atmosphere, and low production capacity and long working hours. Led by lean efficiency improvement and applying the principle of value mobility, propose the parallel improvement of overall value stream and process value stream, and summarize the three main routes of efficiency change: process line, creating efficiency league competition, category line, low efficiency model battle, and team line, teams cross order to achieve balanced production. At the same time, from the direction of dynamic staffing in slack and peak seasons, weekly full load production scheduling, etc., dynamic programming is used to obtain the optimal standard working hours, and multi-dimensional efficiency mode is improved to enable multi variety discrete manufacturing enterprises to improve efficiency, and finally achieve the goal of optimal operating costs. Field implementation shows that the three routes of efficiency based on value stream and dynamic programming play an important role in solving discrete problems, and provide an important basis for improving the efficiency of discrete manufacturing.

Currently, the relationship between VR/AR technology and smart home is still in a relatively fragmented state. Therefore, it is necessary to design scenario solutions for the deep integration of VR/AR technology and smart home. This scene is constructed through the deep integration of innovative VR/AR technology and smart home, including air environment simulation, cooking, and clothing storage scenarios, to solve the problem of VR/AR technology being disconnected from users' actual lives. Through the construction of the above innovative scenarios, VR/AR technology can be truly applied to users' home lives, enhancing the value of technology application and solving the pain points of users' lives. The research results can provide important reference and design methods for the application of VR/AR cutting-edge technologies in user home life.

Nowadays, people pay more and more attention to the health of the home environment. The health function design of household appliances has become an important element in product design. How to improve the health performance of materials has become an important consideration for product designers. Plastic, as the material with the most proportion and the most contact with food in refrigerators, can enhance the antibacterial function of plastic parts and enhance the health competitiveness of products. By analyzing the characteristics of antibacterial agents, combining with the current molding technology of refrigerator plastic parts, the selection and molding technology of plastic antibacterial agents are optimized, the application of antibacterial plastics as health material in refrigerator was introduced.

Modern kitchen life changes with each passing day, the traditional kitchen has long been unable to meet people's various needs. With the popularization of "integration", "intelligence" and "scene", "integrated smart kitchen" has become the focus of kitchen life and kitchen industry reform. Chinese cooking is keen on frying, and a large amount of lampblack will be produced in the process. As the air is sucked into the air duct to cool and condense, the lampblack will adhere to particles of dust and accumulate, resulting in reduced efficiency and attenuation of smoke exhaust performance of the range hood. Aiming at the pain points of oil fume purification, the pure core full dynamic centrifugal oil fume pre-purification device is innovatively designed through CAE simulation technology, which makes the two phases of oil and gas pre-separation, protects the wind wheel and air duct from oil dirt accumulation and pollution, and achieves long-term stable pumping and purification effect, and the measured purification efficiency can reach more than 94%. The separation of liquid grease can be effectively recovered and recycled. The application of the intelligent control integrated system purification technology in the integrated stove can effectively reduce the impact of the integrated stove oil fume on the kitchen environment and health, and promote the development of the integrated kitchen appliance industry purification technology.

With the continuous development of cloud computing technology, cloud native has become an emerging application development and delivery model. Due to its high scalability, flexibility and agility, cloud-native applications are gaining more and more attention in today's software development field. Combined with the domestic mainstream technology environment (Java dominates enterprise-level applications), the road to cloud native is not easy. In the field of cloud computing, the cost of adopting Java is higher than some of its competitors. In this context, GraalVM, which has great potential in cloud-native application performance optimization, has attracted much attention. In order to give full play to the advantages of the cloud-native architecture and provide users with fast and convenient services, compare and analyze traditional Java and native Java applications based on GraalVM from the dimensions of resource occupation and startup speed, so as to help architects or developers in technology selection and improvement guidance on user experience.

The development of voice recognition technology in the smart home appliance industry is becoming more and more mature, and the corresponding detection technology standards are gradually unified and standardized, but due to the difference of test corpus, the test results between different products can still only be used for their own vertical comparison and be short of horizontal comparability, which greatly hinders the development of industry technology. Studies the feasibility and preliminary composition of corpus standardization from three aspects: sentence pattern, function and intelligence level, and provides new methods and ideas for improving the speech recognition testing technology of intelligent home appliances.

By different sources of meat and seafood to separate, purify and identify microorganisms in the low temperature frozen stages of the refrigerator, determine the types of microorganisms in meat and seafood ingredients, and study the sterilization and sterilization effect of ozone, ultraviolet and plasma to refrigerators frozen food. The results show that ultraviolet rays have fast sterilization effect on bacteria and yeast bacteria and high efficiency, that is, the sterilization effect of half an hour reaches more than 99%; while plasma and ozone have a fast sterilization effect on molds and high efficiency, the sterilization effect of 0.5 h has achieved 100%.

At present, the penetration rate of smart home appliances in daily life is increasing. While bringing convenience to people, their security is also increasingly concerned. Starting from the security status quo of smart home appliances, combs the security standards related to smart home appliances at home and abroad, analyzes the security requirements of smart home appliances, takes typical application scenario as an example, puts forward the basic process of security threat analysis, and expounds the construction idea of threat model in detail. It aims to further strengthen the safety research and development level of smart home appliances in China and promote the development of the industry with higher quality.

Hybrid application development based on mobile H5 containers is one of the primary approaches for app development in the current internet landscape. In order to design a hybrid development solution suitable for smart home appliance apps, an in-depth investigation and experimentation of the core technologies and interaction efficiency between Web and native interaction were conducted. This study establishes a methodology for unit testing plugins and devises a mechanism to monitor abnormal operations in H5 business logic and report them. Additionally, an offline packaging strategy was devised to enhance page loading speeds. Ultimately, a hybrid development system tailored for smart home appliance apps was formulated. This system utilizes H5 development for device control pages, resulting in enhanced stability and user experience.

With the breakthrough development of artificial intelligence (AI) technology represented by large language models, AIGC (AI-Generated Content) technology has attracted the attention of the whole society. Through literature review and analysis, the potential applications and challenges of AIGC technology in the home appliance industry were explored, including the traditional AI techniques, such as voice control and facial recognition, as well as new fields such as recipe recommendation, sentiment analysis, speech recognition, and intelligent home assistants. Research has shown that traditional artificial intelligence technology has been successfully applied in the field of household appliances, achieving intelligence and personalization. New directions such as recipe recommendations and smart home assistants are expected to provide a better user experience and more diverse functions. However, AIGC technology still faces challenges such as data volume, computational requirements, biases, security and so on. Addressing these challenges will promote the development of AIGC technology in the home appliance industry, providing smarter, personalized, and convenient home experiences.

Under the smart Internet of Things, huge number of smart devices are connected to the home network, so efficient connection and binding technologies are required. Traditional device network binding requires users to directly operate the device to complete security authentication to ensure user-triggered network configuration operations. However, in the actual application scenario of the user, this kind of process either has a relatively high learning cost for the user, or the user cannot directly operate or it is difficult to operate. The integration of BLE technology and Wi-Fi technology is based on a secure binding scheme based on distance confirmation. BLE technology can realize low-power and short-distance pairing, and Wi-Fi provides high-speed network. Through the cooperation of the BLE broadcast of the device and the Wi-Fi module, mechanisms such as distance authentication, automatic network configuration, and binding can be realized, and batch fast connection and binding of devices can be realized. Compared with traditional schemes, the scheme lowers the threshold for users while ensuring security and privacy, and improves the popularity and use of smart devices in ordinary users' homes.

Presents a layered design scheme of embedded software for air conditioning. According to the characteristics of air conditioning software and the design idea of state machine, this software is divided into task scheduling layer, function logic layer, component driver layer and hardware configuration layer. The rule is: the upper layer can only call the function of its lower layer, and the lower layer can’t call the function of its upper layer. Data is transmitted between the layers by the interface. When one layer needs to be modified, the logic of the other layers is not affected as long as the interface is unchanged.

As an essential component of the indoor environment, the bedroom sleep air conditioning system needs to meet functional requirements while also possessing aesthetic value in its appearance. Delves into the application of "aesthetics and functionality" in the design of bedroom sleep air conditioning systems, offering new perspectives and methods for air conditioning design. Through comprehensive analysis and verified examples, it provides practical guidance for designers and researchers. It explores how innovative design approaches can be employed to create products that are both visually appealing and functional, catering to the evolving needs of users.

With the continuous development of technology, the HMI (Human-Machine Interface) methods are also evolving. In order to enhance user interaction and operational convenience with air conditioners, especially to address the issue of controlling wall-mounted or ceiling air conditioners when the remote control is not available, the implementation of millimeter-wave radar gesture recognition technology on air conditioners has been designed and tested. The accuracy of air conditioner gesture control, as determined through experimental testing, reached 89%, indicating that the application of millimeter wave radar gesture control on air conditioners is feasible and meaningful.

Smart homes are rapidly entering people's lives, but the mainstream smart home scenes in the market are similar. The new scenes developed by various enterprises have not completely solved the pain points of users. On the contrary, some complicated operations will increase the cognitive burden of users and bring new problems to users. Paying attention to user experience is particularly important in smart home scenes. Therefore, by discussing the relationship between user experience and home appliances, we can understand the importance of user experience evaluation for smart scenes, and discuss the process of user experience evaluation for home smart scenes. Based on literature research and years of testing experience, perfects the research process of smart home user experience, and divides it into research process and research process. The research process is aimed at demand research and planning stage, and the research process can be applied to planning, development and marketing stage.

Using several different brands of air fryers and beef patty as cooking materials, the difference and characteristics of cooking performance of different brands of air fryers were studied by using total texture testing method combined with statistical analysis. The results show that there are significant differences in hardness, chewability and elasticity of beef patties cooked by different brands of air fryers with the same volume and power. It shows that different brands of air fryers have different cooking effects under the same volume and power. It is feasible to reflect the cooking performance of air fryer by hardness, chewability and elasticity of beef patties. At the same time, the cooking effect of the beef patties cooked by the air fryer is different in different positions, it can be reflected by the difference in hardness, chewability and elasticity of the beef patties at different positions.

In view of the increasing demand of users for air conditioners, they pay more attention to the comfort and health of air conditioners, and pay more attention to whether the indoor room air environment is good. There are many air conditioners with self-cleaning function on the market. Aims to evaluate the cleaning effect of each self-cleaning function, user experience and other aspects to help improve and modify the self-cleaning function. By simulating the user's environmental do comparison test method, the operation logic of the self-cleaning mode, the state of the air conditioner during self-cleaning, and abnormal sounds were recorded for analysis and comparison, and it was concluded that the four sets of air conditioner realized the self-cleaning function by cooling operation and condensing firstly, then cooling operation and frosting, and then blow air or heating operation to defrost to dry evaporator. The sound of ice cracking will appear in the frost and defrost process of the four sets of machines, similar to "crackling" sound, and the user experience is not good. The frost forming process is the key to the abnormal sound, and further research needs to be conducted through comprehensive evaluation to improve the self-cleaning function and the use experience of the air conditioner.

Nowadays, the home appliance industry has entered a mature stage of industrial development, and the social population is becoming saturated. It is crucial for the home appliance industry to effectively promote the upgrading and replacement of the industry, better meet the diverse needs of different consumer groups for home appliance functions, and obtain new consumption growth points. The policy stimulus of replacing old with new in the home appliance industry is in line with the needs of industrial development and is also a driving force for promoting sustainable development of the industry. Therefore, home appliance enterprises need to seize policy opportunities, take precautions, accurately grasp the industrial environment faced by the home appliance industry, identify market demand, and improve transaction mechanisms. For the government, it is necessary to build a governance mechanism with multiple entities, guided by market demand, and optimize and innovate policies.

The GB/T 17713—2022 standard for range hood products is about to be implemented. The new version of the standard has undergone significant revisions in terms of scope of application, air performance requirements and test methods, noise, etc., adding technical requirements and test methods for working air volume, working noise, appearance sharp edges, etc. This standard is modified based on the actual use of range hoods in China and with reference to relevant international standards, ensuring its foresight, scientificity, and openness. It is the basic standard for the safety and performance evaluation of range hoods and other cooking smoke exhaust devices in China.

By analyzing the regional distribution, annual application trends, applicants, and technical content of IH rice cooker patents from 1987 to present, this study evaluates and predicts China's position in the global IH rice cooker industry and the development direction of technology, providing reference for relevant innovation entities to formulate patent layout strategies. China has replaced Japan as the research and development center of IH rice cookers, at present, the IH rice cooker technology is in the mature stage of technology, and the refined control of each heating stage will be the focus of future research and development. Intelligent, energy-saving, noise reduction, and IH rice cookers specifically designed for special populations may also become research hotspots.

The high temperature, humidity, condensed water, and microwaves inside the cavity of the micro steaming and baking integrated machine can all affect the measurement of steam humidity. By continuously researching methods and instruments for measuring air and steam humidity, a large number of methods and instruments for measuring steam humidity has been developed. Reviews the research progress of measurement methods and equipment for steam humidity, providing reference for the measurement of steam humidity in micro steam baking integrated machines.

Air pollution has become the biggest threat to people's health. The development of human economy has not only caused global warming, but also exacerbated air pollution and reduced indoor air quality in residential areas. The air quality of residential buildings is jointly affected by indoor pollutants, outdoor pollutants, and people's daily activities. Cooking activities, smoking, interior decoration, etc. can all affect the indoor air quality of residential buildings. Long term exposure to over standard environment will endanger human health, increase the incidence rate of various respiratory system, digestive system and other diseases, and even cause cancer. People should pay attention to the quality of indoor air, understand the sources of common pollutants and their impact on human health, and study effective and feasible improvement measures.

To investigate the energy efficiency improvement methods of stationary storage type electric water heaters for the Indian market, analyze the Indian energy efficiency standards, establish a CFD fluid-solid coupled heat transfer simulation analysis method for electric water heaters, and validate the reliability of the simulation method based on experimental results. The quantitative results showed that the impact of foam material thickness and thermal conductivity on energy consumption and proposed optimized solutions to enhance energy efficiency rating of Indian electric water heaters. The increase of the insulation thickness by 5 mm and 10 mm can effectively reduce the standing loss per 24 h by 0.057 kW·h/24 h/45°C and 0.078 kW·h/24 h/45°C, respectively. When the insulation layer is 30 mm thick, the thermal conductivity of the foam material decreases by 0.003 W/(m·K), and the standing loss per 24 h decreases by 0.035 kW·h/24 h/45°C.

To determine the test method of microorganisms in the blender after cooking. The total microbial count and standard bacteria artificial contamination method were used to evaluate the cleanliness and bacterial eliminating rate in the blender, and the pretreatment method of the test method was optimized. The results showed that the total microbial count reached 10⁷ CFU in 72 h after cooking, and the top rim and lid of the blender were the two most serious places for microbial to grow. The influence of standard bacteria artificial contamination method on the test results of bacterial eliminating rate was compared between soymilk making method and non-soymilk making method. The soymilk making method had a low bacterial eliminating rate, however, its parallelism was good and the data stability was higher. The optimized bacterial eliminating rate method can better reflect the cleanliness of blender in real life scenes.

Temperature rise test is an important safety parameter in the general inspection items of electrical products, and its accuracy is crucial to the quality and performance of products. Many standards do not describe the measurement methods of temperature rise in enough detail, resulting in deviations in the experiment that affect the results. In the ability test to measure the surface temperature rise of electrical products by thermocouple method, it was found that the measurement data in our laboratory was low. We need to find out the reasons affecting the accuracy of the temperature rise data and correct them. Through the use of quality control samples, several fixed materials of the thermocouple and the test environment were compared and analyzed. It was found that the low temperature rise data was due to the poor contact between the thermocouple and the measured surface and the air convection caused by the air conditioning in the measurement environment. Satisfactory results were obtained by using high-temperature tape and controlling air convection in the test environment. The conclusion of this study is conducive to the control and optimization of temperature rise measurement capability.

Due to the strict testing requirements for air conditioners exported to the EU, the seasonal energy efficiency testing method of frequency conversion splitters exported to the EU is discussed and analyzed. Through S-A analysis and testing method, it can be concluded that the seasonal energy efficiency affected by each working condition of refrigeration is C>B>D>A, and that the seasonal energy efficiency affected by each working condition of heating average temperature zone is B>C>A>D>E. Standby power and reaching temperature shutdown power have great influence on the seasonal energy efficiency of refrigeration, and the smaller the control power can be realized through electronic control function. The research results will provide readers with a complete set of European Union seasonal energy efficiency testing methods and a complete debugging idea for product development, so that the performance of air conditioners can be fully utilized and the minimum configuration and optimal energy efficiency of air conditioners can be achieved.

According to the requirements and methods of “Guide to the evaluation and expression of uncertainty in measurement” (CNAS–CL01–G003), and “Guide for evaluation of uncertainty in chemical analysis for measuring uncertainty” (CNAS–GL006), analyses the uncertainty of iodine content testing in drinking water by ICP-MS, and evaluated all the components of measuring uncertainty, in order to find out the influent factors and provide scientificbasis for the evaluation. The results show that when the content of arsenic in drinking water is (8.9±0.9) μg/L(k=2). From the analyzing process, we know that standard curve fitting and the testing instrument are the most important components to uncertainty component.