Fault Tree Question Answering (FTQA) is a form of intelligent question-answering system built upon the fundamentals of fault tree analysis, where enhancing efficiency and accuracy are key challenges. To address this, a novel method based on large model decision-making has been proposed. By transforming the fault tree into a Directed Acyclic Graph (DAG) and integrating deep learning and natural language processing technologies, this method utilizes large decision-making models to develop an intelligent question-answering system. This system is capable of effectively understanding and responding to various questions related to fault trees, thereby solving multiple critical technical challenges. Experiments conducted on various types and sizes of fault tree models have validated the significant advantage of this system in terms of the accuracy of responses. Research findings demonstrate that the fault tree question-answering method based on large model decision-making not only holds significant theoretical implications but also exhibits substantial practical value in application. This introduces an innovative approach and tool for intelligent fault tree question-answearing, laying a solid foundation for future research and development.

Performance improvement is always a key breakthrough direction for dishwasher research and development, and it is also one of the main demands of users. Firstly, based on the spray washing technology of dishwashers and the rapid heating characteristics of steam, it is introduced that a steam generator module is added to the dishwasher and the washing concept of dishwasher steam-water mixing washing is proposed. Secondly, the temperature rise data of different test points at inner chamber during different time periods is obtained through prototype test and integrated with the washing characteristics of dishwasher, then it develops a steam using way to improve the washing and drying effect for dinnerware, and also conducts relevant verification experiments. Finally, the applications of steam-water mixing washing technology in other areas such as rapid washing and drying are discussed. Aim to improve the dishwasher performance by combining traditional spray washing and steam washing, the steam-water mixing washing technology is proposed, providing the ideas of the application of this technology in dishwashers.

The heat pump system used in a dryer has the characteristics of miniaturization, closed-loop circulation, operation in high humidity environments, and transient performance. To address the shortcomings of current heat pump dryers, a systematic analysis of the R290 heat pump system used in dryers was conducted from both theoretical and experimental perspectives, focusing on the thermodynamic characteristics of the refrigerant side, the circulation characteristics and energy distribution of the humid air side, and the overall energy loss of the dryer. The theoretical analysis obtained the relationship between the heat entering the drum and the total heat released by the condenser in a closed-loop system. The experimental results showed that the R290 heat pump system had a high dryness at the inlet of the evaporator, which reduced the heat transfer efficiency of the evaporator and increased the resistance along the way. The heat released by the condenser could not all enter the drum. Effective means to increase the heat entering the drum include reducing the amount of re-evaporated water and increasing the relative humidity of the air leaving the drum. The entire dryer had a heat loss of approximately 20%, and an effective way to further improve energy efficiency would be to strengthen the seal of the drum to reduce leakage.

Vitamin D helps the body to absorb calcium sources, D₂ and D₃ have the same effect, which D₂ is mainly from plant foods. Ergosterol, the precursor of vitamin D₂, is more common in mushrooms. Through the study of ultraviolet light wavelength, light work time, light distance, temperature and humidity of the light environment in the refrigerator with low temperature, and the effect of vitamin D₂ on different mushrooms was studied. The results showed that: UVC(270-280 nm), the light time is 2 hours, the light distance is 15 cm, the refrigeration is 4℃, the humidity is 50-60%, the fresh mushroom vitamin D₂ efficiency is greater than 5155%; And because Pleurotus pulmonarius is small, and the light area with ultraviolet is large, so it has a better improvement effect. The above conclusions provide technical parameters for the design of mushroom nutrition improvement scheme in low temperature environment.

As a typical giga cycle fatigue application, valve system has been applied for various compressors and improving the reliability of valves is the key to meet higher frequency and miniaturization in the future. Based on the custom-made impact fatigue testing machine, the fatigue lifes of different valves were tested. It is verified that improving the processing quality, bettering the performance fit between valve plates and flapper valves, and optimizing the microstructure of valve materials are effective methods to enhance the fatigue life of valves. Which are contribute to provide more ideas for the production and processing, structural design, and material selection of compressor valves.

In addition to improving accuracy, the compressor model used in refrigeration system simulation also requires as few experimental samples as possible for model correction. Based on experimental test data, different models are compared. And the compressor model with the smallest experimental data requirement is selected from the models with relatively good accuracy. The results show that for mass flow rate, the reciprocal of the polytropic index is used to correct the pressure ratio term, and the pressure loss of the suction process is considered for characterisation; for input power, high and low pressure and high and low pressure cross terms are used for characterisation, which can meet the requirements of high accuracy and small data requirement at the same time. Only 5 sets of experimental data are required to accurately fit the undetermined coefficients in the compressor model, and the average errors of the model prediction of mass flow rate and input power are within 1.5% and 2%, respectively.

The noise level of electrical products directly affects the user experience and quality of life. The proficiency testing plan for the noise test of electrical products aims to examine the accuracy of the testing technicians' understanding of the current noise testing methods, as well as the noise testing ability of the participants. Through the analysis of the test results, it helps to discover the common technical problems in the test, provide reference information for the further development and improvement of the standards and testing technologies, and at the same time promote the participants to improve the detection level to ensure that the noise of electrical products meets the relevant standard requirements.

The electrification and DC of residential buildings is an important support for the realization of renewable energy consumption in residential buildings, as well as a breakthrough point in building green ecological civilization construction and economic and social development.At present, there is no mature product or experience of DC energy storage type at home and abroad. The household energy management system also needs technological breakthroughs urgently. In view of the above problems, a set of household energy monitoring and management platform based on Photovoltaic Energy Storage Direct Current Flexibility（PEDF） technology has been researched and designed to verify the authenticity and accuracy of power saving in the energy management system.The designed energy management system improves the user experience and provides an efficient and stable energy management solution for the smart home industry.The research provides valuable reference for further improving and promoting the design of DC residential products.

The water circulation air conditioning system using R290 as the working fluid effectively solves the safety problem of R290 air conditioning by using plate heat exchangers to deliver the cooling capacity indoors without the working fluid entering the house. This article establishes an ε - NTU model of the system to simulate and analyze the influence of indoor heat exchanger air volume and water circulation on system performance. The results show that the heat capacity flow rate of circulating water is equal to that of air, which can improve the temperature efficiency of the heat exchanger in most cases. A control method that can accurately control the pump flow rate by only measuring the system temperature is also proposed, which can serve as a basis for optimizing the design of water circulation air conditioning systems.

With the development of artificial intelligence technology, the air conditioning industry has developed a smart air conditioning management system with air conditioning as the main environmental regulation device, expanding the perception range to multimodal modes of people, machines, and environment. From the perspective of human factors, the human body is naturally equipped with a thermal regulation system, which using the human body thermal regulation system to achieve a thermal neutral state, the human body feels warm and comfortable. The human thermal regulation system is also affected by environmental factors. How to dynamically adapt the smart air duct system of air conditioning to the human thermal regulation system is an important research direction for improving human thermal comfort. Therefore, studying the mechanism of human thermal regulation system, analyzing the key factors of human thermal neutral state regulation, and applying it in smart air management system, enables dynamic adaptation of human thermal regulation system and air conditioning smart air management system, realizes systematic regulation of human body, air conditioning, and environment, improves human comfort in indoor environment regulated by air conditioning, and thus enhances human health level.

Under the guidance of the two major themes of “intelligence and health”, consumer demand is becoming more and more personalized and diversified, integrated stove through the multi-functional integrated design, integrated gas stove, steam box, oven and other functions, can achieve a variety of cooking methods, bringing great convenience to the kitchen life. At the same time, there are also technical problems such as unclean oil smoke, increased door temperature, and loud noise. Through innovative intelligent motor technology design, multi-dimensional high-precision sensors are used to build a digital precision motor control logic model. Through CAE analysis, the test and improvement results show that the integrated stove smoke machine can ensure the effective air volume is quickly cleaned, the average efficiency of oil smoke purification is more than 96.3%, and the temperature rise of the door body does not exceed 42.8 ℃. And effective energy saving and noise reduction and improve cooking efficiency. The research and application of the intelligent motor technology in the integrated stove effectively solves the user's pain points in the cooking process and improves the life satisfaction of the smart kitchen.

The efficiency of the air supply motor used in the air conditioning supply system is one of the main factors affecting the air conditioning supply efficiency. Currently, traditional induction motors and permanent magnet synchronous motors are commonly used for air supply motors, such as single-phase AC asynchronous motors, three-phase AC asynchronous motors, brushless DC motors and so on. From the perspective of the development of motor technology, there is still a lot of room for improvement in the topology of these motors. Therefore, the application of air supply motors with better topology and electromagnetic characteristics is an important way to improve the efficiency of the air supply system. Based on the design of the air conditioning supply system, in response to the problems of large motor shaft power, large volume, and large turbulence at the top of the fan inlet faced by large-diameter fans with air conditioning heat transfer requirements, a supply motor scheme using axial flux motors is first proposed, resulting in a smaller and more efficient motor topology structure; Secondly, by introducing the imported turbulent mass into the fast and intelligent full three-dimensional fan blade design method, an efficient rectifying fan blade is designed. Compared with traditional fans, the new type of fan has improved the overall air supply efficiency by 11%, providing new ideas for the design of subsequent air conditioning supply systems.

The main function of the filter element is to filter and purify water. There are many kinds of filter elements on the market, and the material quality and filtering effectiveness are uneven. In order to screen the high-quality filter element and ensure the quality of water in the family, the RFID filter anti-counterfeiting technology is designed and researched in the water purifier. Through this technology, the data interaction between the control system of the water purifier and the electronic tags embedded in the filter element has been achieved and the accuracy of information such as the code, production date, and specifications of electronic tags has been verified. According to the service life of the filter element, the opening time of the pump and the valve, the water flow and other data, the control logic of the water purifier is optimized to meet the high-quality water needs of users. Finally, the application of RFID technology in the Internet of Things is introduced.

The high frequency power electronic converter is used to drive the fan motor and compressor in household variable frequency air conditioner system. It is of great significance to study the conducted electromagnetic interference mechanism of household variable frequency air conditioners and explore effective suppression strategies for improving the electromagnetic compatibility of air conditioners. Focusing on the conducted electromagnetic interference of the electronic control system of household variable frequency air conditioning, a precise time-domain simulation model of variable frequency drive circuit was established. Through the experimental verification of working conditions, the EMI conduction path of the variable frequency air conditioner system was revealed, and feasible suppression strategies were proposed based on the time-domain simulation model, in order to provide scientific basis and technical reference for the electromagnetic compatibility design of variable frequency air conditioner.

Compared with conventional microchannel heat exchangers, insert-plate microchannel heat exchangers have better drainage performance and can improve the problem of condensation and defrosting water retention in conventional microchannel heat exchangers used as evaporators. In order to study the feasibility of applying insert-plate microchannel heat exchangers to window-type air conditioning evaporators, a selection study was conducted on insert-plate microchannel heat exchangers, and the overall system design and performance comparison testing were completed. Research has found that using suitable aluminum insert-plate microchannel heat exchangers instead of copper tube finned heat exchangers for window-type air conditioner evaporators can achieve lightweight design while maintaining the same cooling capacity and energy efficiency ratio of the product. At the same time, it can reduce the refrigerant filling amount and improving the safety of using environmentally friendly combustible refrigerants.

In view of the problem that laboratory measurements cannot fully reflect the real performance of air conditioners, the dynamic performance measurement of air conditioners based on virtual buildings has become a research hotspot. Virtual building features are a key part of the dynamic performance evaluation of air conditioners. This paper firstly analyzes the three methods of obtaining the capability of air conditioners, including enthalpy difference room measurement, on-site operation performance measurement, and laboratory dynamic measurement, and points out that laboratory dynamic measurement based on virtual building is the only way to evaluate the performance of air conditioners. Through simulation and model analysis, the load characteristics of the room under different operating characteristics were determined, and the linear relationship between temperature and load combined with the selection coefficient was proposed to describe the virtual building load. The recommended values of the selection coefficients for the cooling and heating conditions of air conditioners in hot summer and cold winter are 1.33 and 1.50, respectively.

The washing machine cabinet is the key core component. In the process of high-speed dehydration, the box is excited and vibrates, and in order to avoid resonance, a certain margin needs to be reserved for the first-order natural frequency of the box. During the transportation of the washing machine, the box is an appearance part, and if it is obviously dropped and deformed, it will seriously affect the user experience. In this paper, the finite element model of the box and the packaging of the whole machine is established, the static and modal analysis of the box is carried out, and the drop simulation analysis of the whole machine is carried out. The deformation distribution map of the box was obtained, and the structure was optimized, and the performance was significantly improved. This paper can provide theoretical guidance for the design of core components of washing machines.

With the improvement of living standards, consumers' demand for air conditioning comfort and functionality is becoming more and more intense, air conditioning that integrates air purification, odor regulation, sterilization, mosquito repellent and other functions will also become the first choice of the public. By analyzing the installation position and the base material of the existing air conditioner, combining with the test to verify its impact on the user experience and the indoor unit of the air conditioner, the current implementation mode based on the installation position and base material selection in the air conditioner industry is optimized. The purpose of this study is to provide scientific basis and practical guidance for the research and development of air conditioner aromatherapy system and related fields.

The spray system, as the core system of a dishwasher, is a direct reflection to the cleaning performance of the dishwasher. In response to the problem of the decrease in rotational speed of the rocker satellite spray arm during long-term test, there analyzes the force situation and different material effects of the rocker satellite spray arm during the motion, and then proposes a technical improvement based on the original structure design of the rocker satellite spray arm. With adding PTFE gaskets inside the satellite spray arm, the friction at the axis positions of the rocker satellite spray arm is reduced, ensuring the motion stability during long-term test and thus verifying the reliability of the rocker satellite spray arm. Finally it provides the theoretical reference and useful methods for developing the design of rocker satellite spray.

This paper explores the effects of air curtain jet velocity and smoke collecting plate angle on the smoking effect using numerical simulation methods based on an actual kitchen model of the range hood. By analyzing the streamline distribution of smoke, the attraction and traction force of the range hood on smoke are discussed. Moreover, the influence of air curtain jet velocity and smoke collecting plate angle on smoking effect was revealed through statistical analysis of smoking capture efficiency. We found that increasing the air curtain jet velocity can improve the smoking effect of the inland range hood. When the air curtain jet velocity is 8 m/s, the smoking capture efficiency is increased by 60% compared to no air curtain of range hood. In particular, bending the smoke collecting plate of air curtain can enhance the smoking effect, because the Coanda effect and flow separation the escape of smoke is suppressed. When the curvature is 70 °, the smoking capture efficiency is increased by 30% compared to the l smoke collecting plate without bending. Our investigation provides theoretical basis and engineering guidance for the application of air curtain technology in range hoods.

The main differences between the new edition and the previous one of QB/T 1876-2023 “Household and similar hair care appliances “are discussed. Introduce and explain important technical requirements and test methods for air volume and negative ion performance of hair dryers, uniformity of tension of electric hair straighteners, durability of buttons. Assist industry professionals in learning and gaining a deeper understanding of standards.

Ball pressure test is one of the important methods for testing the heat resistance performance of non-metallic materials. In order to ensure the safety of heat and flame resistance of non-metallic materials in use, it is necessary to conduct ball pressure test detection on the materials. In the test, finding the ultimate temperature of the sample often requires multiple repeated tests, which increases the time and complexity of the test. Therefore, selecting an appropriate starting temperature is crucial. Differential scanning calorimetry experiments are accurate, fast, and have a short cycle. In order to quickly and accurately select the appropriate starting temperature, the correlation between ball pressure test and differential scanning calorimetry test was studied. Select commonly used non-metallic materials: PC, ABS, PC/ABS, PP, PA6, PA6/66, PA66, and conduct ball pressure tests and differential scanning calorimetry experiments respectively. Through experimental research, it is found that DSC can be used for pre testing of ball pressure tests to reduce the workload of ball pressure tests and improve testing accuracy, providing theoretical guidance for improving the efficiency of ball pressure tests.

Kitchen fumes, as one of the three major sources of air pollution worldwide, pose a serious threat to human health. In order to the problem of fume filtration and purification, there is an urgent need to find a range hood with an ultra-high purification rate. By experimentally testing and comparing range hood with the new dynamic centrifugal interception device and other cooking fume exhaust devices with similar products on the market, it has been proven that the product with dynamic centrifugal interception device has better oil separation and filtration effects for fume particles with a diameter of less than PM₁₀. This not only improves the quality the cooking environment but also greatly reduces the impact on the external air environment, which is bound to lead the industry's new development momentum and provide strong support for green environmental, and sustainable development.

After 8 hours of random vibration testing, the bottom of the motor bracket of a certain model of air conditioning outdoor unit cracked at the bend. To investigate the cause of the cracking, the fixing position of the motor bracket and base was analyzed, and the impact of the fixing position on the stress amplitude of the motor bracket bend was obtained through theoretical calculations. Through finite element simulation analysis, multiple simulation scenarios were tested to solve the cracking problem of the motor bracket, providing ideas for the structural design of the motor bracket.

The rise of large AI models is rapidly reshaping the smart home sector. However, these systems often struggle with scattered knowledge, scene adaptability, and personalized services. To overcome these hurdles, this paper presents a smart home scenario self-generation technique based on a knowledge tower cluster. We design a layered appliance ontology and integrate large models using a synergistic optimization approach rooted in the tower cluster's knowledge graph, bolstering model reliability and generalization in smart homes. By capturing multi-dimensional inputs from users, devices, environments, and spaces, we create precise user profiles and autonomous scene organizers with graph neural networks and transfer learning. This enhances task adaptability and self-learning, enabling proactive, customized user experiences. Testing reveals that our approach achieves a scenario generation accuracy of over 95%.

The research on intelligentization of home appliances is advancing continuously, and there are many technical deficiencies in the current research and application practice of intelligent control systems that affect the user experience. This study proposes the research of intelligent home appliance control system based on Large Language Model (LLM) to address the shortcomings of intelligent voice interaction control. The content focuses on the training method and parameter tuning of the vertical application of the Large Language Model in the field of home appliances, and the construction of the intelligent home appliance interaction system based on the Large Model is synchronized. Speech Emotion Recognition (SER) and Text to Speech (TTS) are innovatively introduced to construct a whole set of intelligent human-computer interaction system for anthropomorphic applications. The application of this human-computer interaction system can further enhance the interaction and control capability of home appliances, closer to the natural interaction of human beings, shorten the distance between machines and human beings, and significantly improve the user's experience of using the equipment.

The refrigerator compressor generates significant vibrations during operation, and the internal exhaust pipe is one of the main paths through which the vibrations are transmitted outward. The compressor matched with a certain box has a low-frequency noise problem. After experimental analysis, it was confirmed that the first-order resonance of the internal exhaust pipe caused an increase in compressor vibration, resulting in abnormal noise. In response to the low-frequency noise problem of the compressor, the internal exhaust pipe structure was optimized through simulation. Experimental verification showed that the new internal exhaust pipe reduced the vibration and noise of the compressor by 0.09 m/s2 and 0.56dB, respectively, while maintaining the first-order mode unchanged. At the same time, it reduced the peak sound pressure level of the box's fundamental frequency by 10.2dB and the sound power level by 1.5dB.

The laboratoty earthing system is the basic element of laboratory design, which effectively guarantees the tester safety and the accuracy of data. Elaborate on the requirements and functions of the laboratory earthing system, and provides suggestions and technical support for the design, construction and rebuilding of the laboratory earthing system through the analysis and comparison of two earthing system. Finally, it was concluded that an independent earthing system could reduce the interfering signal in the circuit.

Based on MFOP reliability index for gas water heater computer board has carried on the simulation and experimental research of reliability design, through to the water heater burning gas computer board can be based on MFOP reliability index for gas water heater computer board has carried on the simulation and experimental research of reliability design, through the investigation about the present situation of water heater burning gas computer board reliability index analysis, formulate the MFOP reliability experimental study scheme for computer board of gas water heater. Based on the reliability experimental study, different acceleration experimental models were selected for different reliability acceleration experiments, and various acceleration test data under different stresses were obtained. Weibull distribution was used to fit the life distribution under various stresses, and distribution parameters were determined, and relevant parameters were fitted according to the acceleration model. Finally, the multi-failure mode life assessment based on competitive failure model is realized, which provides theoretical guidance for the reliability design of computer board of gas water heater.

By using the CFD numerical simulation method, based on the Euler-Eulerian two-phase flow model, the mathematical model of gas-liquid two-phase flow in the liquid distributor is developed to study the effects of different dryness, mass flow rate and placement methods on the volume fraction distribution, flow rate and distribution performance of gas-liquid two-phase refrigerant in the liquid distributor were analyzed. The results show that when the liquid distributor is placed vertically, the dryness and the mass flow rate have little effect on the distribution performance of the liquid distributor. The dryness and the placement have a greater effect on the gas-liquid two-phase flow of the refrigerant in the liquid distributor. The performance of the liquid distributor placed vertically is better than that of the inclined liquid distributor.

In order to explore the relationship between stew process and soup quality in steaming oven, selected ginseng chicken soup to explore stew process of ginseng chicken soup by analyzing the heating rate, sensory evaluation and ginsenoside content. The results showed that the appropriate combination of baking tube and steam can improve the sensory quality of the soup and be beneficial to the dissolution and retention of ginsenosides in the soup by comparing 4 kinds of stew process in steaming oven. In process D (stewed at 220 ℃ for 30 min, then turned at 150 ℃ for 30 min, roasted and steamed), ginseng chicken soup has obvious umami, rich and mellow, and ginsenoside Re and Rg1 contents in the soup reach 15.01 mg/L, which is a steaming oven stewing process with good nutrition retention and good sense of stewing soup.

Aiming at the problem that it is difficult for existing environmental appliances to improve human sleep environment in real time and personalized, a new technology for detecting human sleep signs based on ultra-wideband radar was proposed. The technology uses ultra-wideband radar to capture physiological signals during sleep. The classification model is constructed by deep neural network to realize real-time and accurate recognition of sleep stages. Further, according to the sleep staging results, the system automatically executes the corresponding environmental control logic to optimize the sleep environment. In the verification stage, a set of air conditioning automatic control system was established. Through the effect test, the accuracy of the system in detecting sleep stages and the actual operation performance of the functional logic were verified, which proved that the system has certain potential to improve sleep.

The high-speed operation of a rolling rotor compressor with a high-thickness motor has a significant impact on the pump structure. To improve its reliability by adopting a double-support structure, in order to study the factors affecting the reliability of the double-support structure and make the structure mass-producible, simulation methods such as shaft system lubrication and fluid as well as experiments are used to confirm the relevant laws of the sliding split-type double-support structure on the reliability of high-thickness and high-speed compressors, and corresponding improvement measures are proposed. The results show that by enlarging the motor bearing clearance, miniaturizing the double-support structure, adding a shaft sleeve to the motor bearing, and optimizing the internal flow field, the reliable operation and implementability of high-speed and high-thickness compressors can be satisfied.

The air-conditioning industry consumes about 20 per cent of the total electricity consumed by residential buildings in the country; one of the ways in which the air-conditioning industry has addressed the growing demand for heating in the winter is to add electrically assisted heaters to indoor units. However, the efficiency of converting electrical energy into heat is much lower than the energy efficiency of air conditioners in heating mode. Prolonged use of electrically assisted heating can have an impact on air conditioning energy consumption and energy efficiency. In order to study the specific impact of energy consumption and energy efficiency of air conditioners using electric auxiliary heating in typical residential buildings, a certain model of 2HP air conditioner model was selected for multi-operating condition measurement, and the predicted curve of air conditioner performance for the whole year was obtained through data analysis, and a model was established for a certain residential house type, and the predicted power consumption of the living room in the whole year of the use of electric auxiliary heating in the 2HP air conditioner and the unused electric auxiliary heating was calculated through the simulation of the outdoor meteorological conditions in Nanjing, as well as the impact on the energy efficiency of the air conditioners. The results show that a typical residential building in Nanjing consumes an additional 44 kW·h of electricity in the living room with 2HP air-conditioning with electric auxiliary heat, which reduces the seasonal energy efficiency (HSPF) by 12.87% during the heating season, and reduces the annual energy efficiency (APF) by 5.61%.

Deep learning, particularly convolutional neural networks (CNN), has garnered significant attention in the field of building energy systems. In the context of fault diagnosis for air handling units (AHU), the effectiveness and applicability of CNN's diagnostic performance require further validation. Additionally, the lack of interpretability in CNN fault diagnosis models hinders their broader application in practical engineering. To address these issues, utilized the publicly available ASHRAE RP-1312 AHU fault data to develop a fault diagnosis model based on CNN, and employed the layer-wise relevance propagation (LRP) method to interpret the CNN model. The results demonstrated that the CNN-based diagnostic model exhibits good applicability, with an average diagnostic accuracy of 99.94%. The LRP method provides strong interpretability for the CNN model, and identifies the diagnosis mechanism of the model in the decision-making process. Finally, an in-depth analysis was conducted on the impact of model parameters such as the number of convolutional layers, learning rate and β parameter on the interpretation results.

To study the effect of suction refrigerant quality on R32 rotary compressor performance, the calorimeter method with the function of suction refrigerant quality was used to study the performance of compressor by changing the suction refrigerant quality and analyzing theoretical refrigeration cycle. The results showed that: under the condition of superheating, the suction state had little effect on the compressor's volumetric efficiency and isentropic efficiency. Under the condition of two-phase, the compressor's volumetric efficiency and isentropic efficiency decreased with decreasing suction refrigerant quality. Compared to refrigerant superheating suction, the decay ratios of volumetric efficiency and isentropic efficiency were 3.3%, 8.0%, and 8.3%, 14.8%, for suction refrigerant quality ratios of 0.94, 0.88. The actual compressor discharge temperature had a linear correlation with the suction refrigerant quality. Under the condition of two-phase, the mass flow rate is affected by suction density and volumetric efficiency. The capacity and EER had a maximum value at a suction refrigerant quality ratio of 1. Under the condition of two-phase, the attenuation of volumetric efficiency and isentropic efficiency changes the trend of EER curve.

Air-source heat pumps typically use two defrosting methods during winter heating operation: reverse cycle defrosting and hot gas defrosting. Compared to reverse cycle defrosting, hot gas defrosting has the problem of longer defrosting time leading to poor thermal comfort in the room. Through theoretical analysis and experimental verification, the impact of the cold surface temperature of the outdoor heat exchanger on frosting and defrosting was studied. The results showed that the heat loss during the hot gas defrosting process is significantly higher than that of reverse cycle defrosting. At the same time, to evaluate the changes in frosting duration and defrosting duration more reasonably, an evaluation index for room temperature changes during the defrosting period was introduced. Using reverse cycle defrosting as a control, experiments verified the changes in frosting duration, defrosting duration, and room thermal comfort under different defrosting strategies. The results showed that under the same experimental conditions, by optimizing the hot gas defrosting strategy, the heating run time can be shortened by 2.5% to 14.9%, and the defrosting time can be reduced by 10.8% to 21.1%; the room temperature drop during the defrosting period can be reduced by 0.36 ℃ to 0.9 ℃, and compared to reverse cycle defrosting, the room temperature drop can be reduced by 1.76 ℃ to 1.88 ℃.

An experimental study was conducted to investigate the reasons for the fluctuation in the cooling capacity of a certain 36000 Btu/h capacity home air conditioner, which was determined to be non-compliant based on the inspection results during the mass production quality control. Six optimization schemes were proposed and experimentally studied from the perspectives of the evaporator, condenser, and compressor to address the reasons for the fluctuation in the cooling capacity of the air conditioner. The results show that the overheating situation of the prototype evaporator flow path is consistent with the wind speed distribution on the evaporator surface. Optimizing the evaporator flow path from 9 inlets and 9 outlets to 10 inlets and 10 outlets has a good effect on the fluctuation of the whole machine performance. At the same time, replacing a certain brand's 26.5-liter compressor based on this scheme can significantly improve the fluctuation of the whole machine's performance, with an increase in capacity of up to 4.7% and an increase in energy efficiency of up to 7.1%. This study provides an effective solution for the capacity fluctuation of the whole machine, and provides relevant guidance for the peers to encounter similar problems in the future.

A comparative study was conducted on the energy-saving effect of a certain AQR-TZ42k refrigerator under different capillary flow conditions. The experimental study found that: using 12 L/min, 7 L/min, 5 L/min capillary flow were tested, when the capillary flow is 5 L/min, the minimum power consumption in the stable section of the whole machine is 0.70 kW·h/24 h, with the increase of the flow, the power consumption increased by 3%, 14% respectively. Dual capillary time sharing control, the capillary flow rates of 5 L/min (low load) +5 L/min (high load), 7 L/min (low load) +7 L/min (high load), 12 L/min (low load) +12 L/min (high load) were used for the test, respectively. When the combination of 5 L/min (low load) +5 L/min (high load) is adopted, the power consumption of the whole machine (including the defrosting section) is the lowest 0.80 kW·h/24 h, and the power consumption increases by 6% and 19% with the increase of flow. The experimental result proves that the energy saving effect of the refrigerator is improved by controlling the capillary flow rate by time sharing.

By providing simplified computational strategies, this study achieves the concurrent topological optimization of the entire range hood system and its application research, and validates the reliability of the optimized configuration through experimental testing. The optimization results show significant configuration characteristics in the flow channels on both sides of the centrifugal fan inlet; compared to the original flow channel, the low-speed vortex area in the topological configuration channel is further away from the fan inlet, reducing the inlet blockage and enhancing aerodynamic performance. Experimental data indicate that the topologically optimized channel mainly affects aerodynamic performance under high flow conditions, with an increase of 0.65 m³/min at 400 W air volume and an improvement of 0.93% in maximum total pressure efficiency. Noise spectrum analysis shows that the topological configuration channel can reduce the sound pressure in the high-frequency range dominated by aerodynamic noise, resulting in a reduction of 1.14 dB(A) in the overall working noise of the system. In summary, the topological configuration obtained through the adjoint topological optimization method and simplified computational strategies has a certain degree of reliability, providing an effective reference for the performance optimization of the entire range hood system.

During the dehydration process of the washing machine, the vibration of the drum is a key factor affecting the normal operation of the drum washing machine. Measuring the transient displacement of the drum has always been a hot and challenging research topic. Compared to displacement measurement, acceleration measurement is more straightforward. Analyzes the data obtained from spatial acceleration sensor testing. In response to the influence of DC components and noise signals in the data, the fast Fourier algorithm is used to filter and integrate in the frequency domain to obtain the required drum displacement parameters, which are then calibrated with the displacement curve obtained from the laser sensor. Experimental results have shown that the displacement curve obtained by using the frequency domain integration processing method approximates the actual displacement curve with high data accuracy. It can monitor the vibration of the washing machine drum through changes in displacement, and effectively control the vibration of the washing machine.

The design of the inner bracket of an electric water heater has a great influence on the load-bearing capacity of the electric water heater. In order to study its influence on the load-bearing performance of the electric water heater and summarize the design method, the strength simulation and experimental research of the inner bracket of the electric water heater were carried out. Through experimental research, the influence law of different materials and structures of the inner bracket on the load-bearing performance of the electric water heater was obtained. Based on experimental research, the influence law of different materials, lengths, thicknesses, widths, heights, and related angle changes on the load-bearing capacity of the electric water heater was obtained through finite element simulation analysis for different material and structural designs, providing theoretical guidance for the subsequent design of the inner bracket of the electric water heater.

In response to the issue that building grilles affect the high-temperature refrigeration performance of air conditioners, this paper first uses CFD numerical simulation method to calculate the air flow loss caused by grilles, and analyzes the flow field distribution of outdoor units of air conditioners inside and outside the grilles. In addition, experiments and numerical simulations were conducted to investigate the improvement of high-temperature refrigeration performance by installing the outdoor unit, adjusting the outlet angle, and adding a guide coil. Research has shown that after installing building grilles, the air outlet grille pass rate of outdoor units is 16.68%. To increase the air output, try to place the outdoor unit tightly against the grille during installation, reduce the distance on the front side, and increase the distance on the left side if the distance and installation permit. It is recommended that this position be greater than 170 mm. Concentrated air output can improve the grid air output rate, reduce the air output angle from 45 ° to 0 °, and increase the grid air output by 76.20%. The installation of air guide rings on the grille has improved the performance of the air conditioner inside the grille. The grille pass rate can reach about 50%, the cooling energy efficiency can be improved by 4.53%, the cooling capacity can be increased by 73.08%, and the cooling capacity can reach 90.82% without the grille.

The motor bracket of the air conditioner outdoor unit is subject to a variety of excitation by the motor and fan, and is one of the important components in the structure of the whole machine. However, at present, there is less research on the vibration and noise failure form and mechanism generated by its excitation in the industry, and thus there is no clear and specific requirement on the design of vibration and noise of the motor bracket, which results in low design efficiency and potential market quality risk. We first analyze the modal simulation and working deformation test of the motor bracket to investigate the actual vibration form of the motor bracket; then we use the frequency sweeping test method to study the contribution of vibration noise of the motor bracket caused by various types of excitation, and its impact on the vibration noise of the whole machine. It is found that under the current structural form, only the fundamental frequency vibration excitation caused by fan dynamic balancing has a greater impact on the vibration noise of the whole machine, while other excitations have a smaller impact.

Softener usage is growing these days since textile care concept spread widely in the marketing. However, the effect on textile based on softener is difficult to evaluate for consumers. Focus on the textile properties of antistatic, softness and fragrance remaining to analyze the influence of different softener amount. According to the analysis, evaluation methodology of softener usage can be provided, which will be helpful for the process design of automatic dosing washing machine product.

This article studies and analyzes the reasons for the low energy efficiency and inability to meet customers' personalized intelligent health function needs of a certain category of wall mounted small multi unit air conditioning products. In response to the adverse effects of low energy efficiency products and wall mounted multi unit air conditioning products without personalized intelligent health functions on enterprise sales, targeted analysis of the reasons and special measures are carried out to solve them. Optimization solutions for improving cooling capacity, increasing energy efficiency ratio, and personalized intelligent control of small multi unit air conditioners are proposed. After the completion and implementation of the solutions, good technical and economic benefits have been achieved.

In recent years, with the development of economy and the improvement of people's requirements for quality of life, the demand for fresh air conditioning in the market has increased. However, due to the high manufacturing cost of fresh air module, it is difficult to promote the use of fresh air. In order to reduce the production cost of the fresh air module, this paper proposes a design scheme of the fresh air module. By optimizing the structural parts of the fresh air module, only a single inlet hood and volute are used to realize the fresh air function. The theoretical analysis and experimental verification are carried out to reduce the noise and air volume generated by the parts. The verification results show that the scheme can effectively reduce the production and manufacturing cost of fresh air, and maintain the fresh air volume and noise.

To improve the energy efficiency of air conditioners in the industry, focuses on the heat exchanger (evaporator and condenser), using the existing 5 mm heat exchanger to conduct theoretical and experimental comparisons from three aspects: fin type, fin quantity, and tube spacing, under the condition of consistent end plate spacing and air conditioner housing. The best heat transfer efficiency and cost-effective heat exchanger are selected to achieve energy efficiency improvement while ensuring the cost-effectiveness of the air conditioner.

The energy efficiency of air conditioning units is the threshold for products in various countries, which directly determines product quality and is also a requirement for promoting energy-saving and dual carbon initiatives. From the technical point of view of improving the energy efficiency of the air conditioning system, a high energy efficiency product is designed from the perspective of box size and system component matching. Taking the 60K rooftop machine as an example, by selecting multiple system components and conducting multiple rounds of matching and coupling, the optimal combination of box size, wind field, and heat exchanger is ultimately achieved to determine the best design solution.

Focusing on lightweight and vibration reduction optimization design in air conditioning systems, this paper explores how to integrate these two key technologies in the structural design of air duct fan plates through theoretical analysis, simulation, and experimental verification. After testing and comparison, it was verified that the fan plate designed through topography optimization not only improved its stiffness performance, but also achieved a weight reduction of 16.7%. This method provides a reference for research and application in the field of air conditioning.

The cross flow duct fan is limited by the form constraints of suspended ceiling installation, and there are significant differences between product design and actual use conditions. In addition, the cross flow fan itself has the flow field characteristics of eccentric vortex instability, which is affected by upstream guide components such as suspended ceiling air intake grilles, resulting in a decrease in fan duct performance and noise deterioration. Therefore, it is necessary to conduct research on the performance impact of cross flow duct fans under different intake conditions. In order to study the impact of intake conditions on the performance of the cross flow duct fan, summarize design optimization methods, and conduct experimental testing and simulation mechanism research on the free intake and lower intake conditions of the cross flow duct fan. Under the condition of lower air intake, a dual guide arc flow channel scheme is adopted, and different parameter combinations of dual guide arc flow channels are designed to optimize the optimal point of multi parameter combination, improve flow distribution, increase air volume, improve flow efficiency, optimize the aerodynamic noise performance of the fan duct, and provide theoretical guidance for the design and development of subsequent cross flow duct fans.

The promotion of heat pumps is of significant importance for global carbon peak and carbon neutrality goals. Reliable operation across a wide temperature range is both a market demand and an industry challenge. Among the key factors affecting the reliability of heat pump systems under ultra-low temperature conditions is the compressor oil return issue. Experimentally analyzes the cold-start dynamic characteristics of compressors under ultra-low temperature conditions. It was found that during cold start, the compressor experiences a period of oil starvation under a ramp-up frequency control strategy. The study quantitatively investigates the effects of compressor operating frequency and system standby time before cold start on oil starvation time. The results indicate that as the frequency increases, the oil starvation time exhibits a trend of rapid initial decrease, followed by a slight rebound, and then continued decrease. Conversely, as standby time increases, the compressor oil starvation time shows a gradual reduction. These findings provide guidance for the design and use of heat pumps, particularly in ultra-low temperature environments.

In the design of outdoor finned tube heat exchangers, the traditional approach is to incorporate subcooling pipes at the bottom to suppress frosting. However, this method has certain limitations because the refrigerant temperature inside the subcooling pipes is usually higher than the ambient temperature, which not only leads to the waste of heat exchanger area but also increases additional design costs. To address this issue, researchers have designed a heat exchanger process without subcooling pipes, and by introducing superheated refrigerant into the bottom of the heat exchanger, they have achieved the dual purpose of full flow path heat transfer and frost suppression. Experimental research analysis indicates that the performance of heat exchangers using the subcooling pipe-free scheme has been enhanced. Specifically, compared to conventional heat exchangers, the heating duration of this design's unit is extended by about 15%, the heating capacity is increased by about 8.2%, the heating energy efficiency is improved by about 5.4%. These improvements contribute to the development of more efficient and comfortable air conditioners in the heating-oriented field.

In order to improve the performance of air conditioning, the material selection of the expansion tube in the two units is mostly copper, with the rapid development of air conditioners and the continuous rise of international copper prices, the heat exchangers used in the refrigeration and air conditioning industry are gradually developing in the direction of high energy efficiency, small volume and low cost. The use of smaller pipe diameter copper pipe or directly reduce the number of copper pipe can meet the above needs. Taking the 2 P ceiling machine as the research object, the evaporator uses D5 copper tube, and the upwind heat exchange area and the constant number of copper tubes are controlled to be unchanged. The temperature difference at the outlet of each branch is controlled within 3 ℃ by adjusting the evaporator shunt capillary tube and adjusting the shunt, and the APF before adjustment is 3.37. After adjustment by two ways, the APF is 3.57 and 3.6, respectively, with an increase of 5.9% and 6.8%, through the final result comparison, it can be concluded that the flow path uniformity has a great impact on the overall performance and energy efficiency of the ceiling machine.

The load of air conditioners has the characteristics of large quantity, high proportion, energy storage capacity, and corresponding service life to peak electricity consumption periods. The study of air conditioner load has been applied in the dispatch of China's power system, improving the flexibility of the power system and having great potential for overall regulation. Air conditioner load modeling is the foundation of air conditioning system design, operation, and optimization. With the development of technology, models will become more integrated and intelligent. As a flexible resource on the user side, air conditioners play an important role in the power system, helping to improve the regulation capability and operational efficiency of the power system. In the future, air conditioner load modeling will be integrated with multiple disciplines to promote the development of innovative technologies and provide more intelligent solutions for smart buildings.

When the air conditioner of the unit continues to operate in high temperature and high humidity environment, it is easy to trigger the shutdown of high pressure protection frequently, which will affect the comfort of users. In order to solve this problem, through the experimental study of air enthalpy method, the variation law of high pressure with different indoor dry and wet bulb temperatures and outdoor ambient temperature during refrigeration of unit air conditioning system is summarized. On the basis of experimental research, aiming at the pain point of this air-conditioning industry, this paper puts forward some solutions, such as setting the phase current parameters of the air-conditioning compressor, correcting the air-conditioning target frequency through the relative humidity value detected by the indoor unit humidity sensor, and controlling the outdoor unit coil sensor and defrosting sensor separately, so as to provide reference for the subsequent air-conditioning comfort and reliability design.

Mechanical ventilation could effectively manipulate the air quantity and quality that enter the room, while building air tightness is the key factor affecting its ventilation performance. This study utilized carbon dioxide as a tracer gas and investigated the removal effect of unidirectional and bidirectional ventilation systems on indoor CO₂ under different building air tightness conditions. The experimental results shou that room air tightness directly determines its ventilation effect for unidirectional ventilation system. Under a certain room air tightness, there is an optimal design ventilation volume, below which increasing the air volume has a greater impact on improving the ventilation effect. When the air volume is higher than this, the ventilation effect is less improved by continuing to increase the air volume. For bidirectional ventilation system, the ventilation effect mainly depends on the coupling of air tightness with input-outlet air volume parameters. By optimizing the air volume parameters, the same air exchange effect could be achieved in rooms with different air tightness. To sum up, the influence of building air tightness on the performance of different mechanical ventilation systems is studied, which provides theoretical guidance for the design and optimization of mechanical ventilation systems.

Photovoltaic air conditioners can solve functional problems in special power consumption scenarios, such as communication equipment rooms in remote areas, isolated island lighthouses, etc. It can also save electricity costs for household users. By simplifying the design, the expensive special photovoltaic converters and batteries of traditional photovoltaic air conditioners are removed, and the manufacturing cost of photovoltaic air conditioners is effectively reduced. The controller actively adjusts the bus voltage to realise the adaptive distribution of photovoltaic-mains functions, and the maximum power point tracking algorithm is built into the controller, which improves the power generation efficiency of photovoltaic panels. It takes into account the manufacturing cost and use cost of photovoltaic air conditioner, and realises the function of flexible switching between photovoltaic air conditioner mains power and photovoltaic power supply.

Primarily investigates the metabolic characteristics of fruits and vegetables under alternating electric fields, providing a preliminary assessment of the preservation mechanisms of these fields. This research aims to offer a foundation for future applications in refrigerator environments. Evaluates the actual effects of the electric field by analyzing its impact on the sensory qualities of fruits and vegetables, ethylene release metabolism, and respiratory intensity metabolism under refrigerator conditions. Test results indicate that under low electric field conditions (30 V~100 V), the metabolism of fruits and vegetables, as well as ethylene synthesis metabolism, are inhibited. These conditions are favorable for the long-term storage of food materials. Conversely, under relatively higher electric field conditions (500 V~1000 V), the metabolic intensity and ethylene synthesis volume of the food materials increase, which is beneficial for the ripening of immature, climacteric fruits and vegetables.

The outlet temperature is a key factor in the comfort of air conditioning during heating. When the outlet temperature is low, the human body feels cold air blowing, which seriously affects the user's experience. In order to solve the discomfort problem caused by the low heating air temperature of the air conditioner, without changing the system configuration and increasing costs, the heating control function logic is optimized to achieve an increase in the outlet air temperature. The same prototype was used in the same laboratory to compare the heating capacity and air outlet temperature of the optimized logic before and after optimization. The results showed that the average air outlet temperature increased by 1.1 ℃ to 2.9 ℃, effectively improving the comfort of air conditioning heating.

High-efficiency air conditioning products have been the mainstream of market competition. However, with the maturity of technology and the trend of product standardization, especially for the relatively simple structure of household air conditioning indoor units, it is difficult to achieve the rapid improvement of capacity and energy efficiency. Therefore, optimizes the air duct, increases the cross-flow fan, breaks the existing product structure fortress, improves the air volume of the air conditioning indoor unit, and optimizes the evaporator pipeline design to achieve the energy-saving goal. The experimental results show that the newly developed air-conditioning model is in line with the current market energy-saving trend, and its air volume can be increased by up to 204 m³/h, and the single-point energy efficiency of the medium and high frequency test points is significantly improved, which is increased by about 4%, but the load of the low-frequency test points is increased, and the single-point energy efficiency is reduced by up to 1.34, so that the seasonal energy efficiency is comparable to that of the original model.

Shovel tooth technology is a kind of shovel chip machine to cut a whole piece of aluminum or copper into a standard spacing, a certain thickness of products New material processing technology, can be applied in the radiator field. Uses Coil Designer to make simulation comparison, and analyzes the heat dissipation effect of shovel tooth radiator and microchannel radiator under the same conditions. The results show that compared with the microchannel radiator, the heat dissipation effect is better, the surface temperature distribution is more uniform, and there is no obvious dust attachment on the surface, which provides the test data and reference basis for the selection of the main engine heat exchanger.

In order to solve the problem of insufficient anchoring force of current expansion bolts, different types of expansion bolts on the market were referred to, and anchoring force tests were conducted on different walls. After analyzing the test results, it was found that there were deficiencies in the current expansion tube, and improvements were made accordingly. Added guide holes and maze shaped openings to enhance its guiding performance. Select the appropriate specification for wooden screws based on test results and the required torque value for tightening.

As a frequently used appliance in the kitchen, the stability of the range hood installation is particularly crucial. By studying the cracking problem of the fan frame hook hole discovered in the trial feedback of new products, exploring the root causes of defects in the manufacturing process, taking the hook hole of the fan frame in the key component of the range hood as the research object, designing different hook hole structures to affect the installation efficiency of the electrical appliance, analyzing four typical types of fan frame hook hole structures in the market, and simulating and comparing the differences between the four structures in the maximum stress value and maximum stress concentration area. Using an electronic universal material testing machine, the ultimate bearing capacity of hook holes with different structures is tested to obtain their load-bearing limit values and deformation forms of the hook holes. The results show that considering the optimal strength and the most uniform stress distribution, the deformation degree of the upper installation contact position of the hook hole in structure C and D schemes is relatively light. The addition of reinforcement technology at the installation contact position of the hook hole improves the strength of the hook hole.

During the operation of the air-conditioning deflector, the motor gears continuously mesh and are subjected to alternating loads. It can easily cause fatigue fracture and affect the movement of the air-conditioning fan panel, which affects the air supply function and overall reliability of the air-conditioning system. Therefore, conducting research on the strength and fatigue life analysis of the motor gears has important engineering significance. Based on the finite element method, the strength and fatigue life of the motor gear of the air-conditioning fan plate were analyzed. Firstly, a simplified finite element model of the motor gear set was established to obtain the gear strength. Furthermore, through Abaqus and Fe-safe joint simulation, the Wöhler curve of the gear material was fitted, and the fatigue life of the gear was predicted, which met the requirements under nominal torque. Finally, the reasons for fatigue fracture of gears under extreme conditions were discussed, providing reference for the structural reliability design of motion mechanisms and the selection of motor performance.

The thermal expansion valve is still widely used in the commercial air conditioning field due to its advantages of automatic flow regulation, easy installation and maintenance. It is crucial to make the best use of its key role. This article studies the influence of adjusting the thermal expansion valve of the air conditioning unit on system performance and other parameters during refrigeration operation. It is found that there is an optimal static superheat of -1.5 K during the matching test between the thermal expansion valve and the whole machine, which maximizes the performance of the system. At this time, the superheat degree at the outlet of the evaporator is 3.7 ℃, the low pressure of the system is 0.81 ℃, and the outlet air temperature reaches a minimum of 14.2 ℃, achieving good user comfort, the highest energy efficiency, and achieving the goal of energy conservation and emission reduction.

Surge is the main item in the electromagnetic compatibility test of refrigerator, and it is easy to fail the test, one of the important reasons is that the insulation of the compressor motor is insufficient and the inverter circuit board is damaged. If the compressor motor insulation is broken down, there will be a large surge current through the inverter circuit components and the components will be damaged. In this paper, it is analyzed that the surge test level is 4 kV, and the resonant amplification of the common mode inductance and Y capacitance of EMI filter circuit and the distributed capacitance of compressor let the voltage between the winding and the casing of the compressor reaches above 5.5 kV. The electrical gap between the winding of the motor in the compressor and the seat spring (connected with the iron core and the casing) is small, and the gap is easy to break down. After the breakdown, a large surge current will break the IGBT of the inverter circuit, burn the inverter board, and the surge test of the refrigerator cannot pass.

This article introduces the structure of household refrigeration compressor motor, and classifies the typical phenomena of motor burnout. Aiming at the phenomenon of motor burnout in household refrigeration compressor, through the method of establishing motor model and external circuit coupling, the distribution of winding temperature under overload, short circuit between windings, short circuit between windings is analyzed experimentally, and the root cause of motor winding burnout is found out. It is convenient to put forward improvement scheme for motor burnout fault of refrigeration compressor in later period.

Study aims to explore the influence of the variation of the inlet size of the DC fan in water heaters on the performance of the fan. Through a combination of experimental tests and numerical simulations, the performance parameters such as the flow rate, pressure, efficiency, and noise of the fan under different inlet sizes were analyzed. The research results show that the reasonable adjustment of the inlet size can significantly optimize the performance of the fan, providing important theoretical basis and practical guidance for the efficient operation and low-noise design of water heaters.

China is a copper importing country with scarce copper resources, high dependence on foreign countries, and insufficient pricing power, while aluminum resources are abundant, making it a major exporter of aluminum. Copper prices continue to remain high and are on the rise, putting increasing cost pressure on air conditioning companies, and the demand for “aluminum replacing copper” is becoming increasingly urgent. In order to study the feasibility of aluminum tube evaporators in household split machines, based on experimental research, an analysis and evaluation were conducted from three aspects: performance, reliability, and manufacturability. Through experiments, it was found that in terms of performance, under the same pipe diameter, the performance of aluminum tube evaporators is about 1.5% lower than that of copper tube evaporators; In terms of reliability, optimizing the design of copper aluminum solder joints in the flow path and selecting stainless steel materials can meet the requirements of pipe pulling, electrical safety, and corrosion resistance; In terms of manufacturability, although the automatic welding rate has decreased, the overall number of welding points is not large, which has a small impact on actual production. At the same time, welding problems can be solved through integrated end plate design or replacement of stainless steel material.

Air conditioning cabinet panel by the floor and decorative board by adhesive bonding, as the cabinet in recent years appearance decorative board material change and appearance structure of beautiful design, the strength of adhesive volume ratio requirement is higher and higher, and the production process is gradually turning to automation, high efficiency, low cost and low pollution, the original VHB double-sided adhesive paper can not meet the demand of the existing process. In order to find the strength of VHB double-sided adhesive material, and innovate the existing production process, through the study of the existing PUR bonding mechanism, bonding process and related performance test results, and compared with the performance of VHB adhesive paper and related process, proved that the PUR hot melt adhesive process instead of VHB adhesive paper in the air conditioning cabinet panel bonding process can improve product performance and increase efficiency.

The research and development of the flame retardant modification of thermoplastic polymer materials are reviewed. The combustion process and the flame retardancy mechanism of thermoplastic polymer materials are introduced. The current research status and modification methods of flame retardants were reviewed. The present research status and modification methods of flame retardants were summarized. The mechanism of gas phase and condensed phase were the way to achieve flame retardant effect of modified polymer materials. Halogen-based, phosphate-based and expansive flame retardants are common flame retardant modifiers. Due to the advantages of simple process and easy operation, the preparation of flame retardant polymers by blending method were widely used at present. However, the poor compatibility between flame retardants and substrates, low mechanical properties of materials, and easy precipitation of flame retardants were the main problems limiting the development of this method. Compared with the blending process, the co-polymerization flame retardant modification process was more complex. However, excellent flame retardant effect can be achieved on the basis of low amount of flame retardant, which is an important advantage of this method. In addition, materials prepared by copolymerization can obtained more durable flame retardant properties, which is an important direction of current research. Considering the factors of material preparation process, production cost and application scenario, thermoplastic flame retardant polymers of kitchen appliances will gradually develop in the future towards halogen-free environmental protection, aging resistance, long flame retardant life and low-cost preparation.

Home appliances face various transportation issues, especially accidental drops and impacts, which can lead to functional loss or weakening, as well as cosmetic damage. To avoid such problems, the traditional and conventional design approach is to conduct physical verification in a laboratory. The rectification experiment usually requires multiple rounds of verification, and this method has a long experimental cycle and high development costs. Home appliances encounter a range of transportation challenges, particularly unintentional falls and impacts that may result in loss of functionality or structural integrity, along with aesthetic damage. To mitigate these issues, the conventional design methodology typically involves physical testing conducted in a lab setting. This rectification process often necessitates several verification rounds, leading to extended experimental timelines and elevated development expenses.

Based on the combination of theoretical analysis and simulation, optimizes the foam structure of an air conditioner pendant. Firstly, according to the theoretical calculation, the theoretical calculation values of foam thickness and contact area are given; Secondly, the load on the foam at the typical moment is extracted by means of drop simulation; Then, with the stress as the constraint condition and the energy absorption of foam as the optimization goal, the optimal optimal material distribution of the original foam structure are analyzed by using the topology optimization method. Finally, by combining the topology results and drop simulation results, the final packaging design scheme is obtained. The scheme was verified to be qualified by the protection test, and the amount of packaging material was reduced by 7% compared with that before optimization, realizing the lightweight design of packaging foam under the condition of ensuring the structural strength.

In order to realize the automatic assembly of automatic feeding, the snap-action thermostats are planned to adopt the feeding method of vibrating plate vibration. In order to study the influence of vibration on the performance of the snap-action thermostats and verify the reliability of the snap-action thermostats affected by vibration, the vibration-related experimental research and analysis of the snap-action thermostats were carried out. Through experimental research, the influence of different reset methods and different materials on the vibration of the snap-action thermostats were obtained. On the basis of experimental research, the test data were statistically analyzed by MiniTAB software for the snap-action thermostats with different operating temperatures, such as variance and time series, and the intuitive operating temperature change trend was obtained. Through the physical analysis and structural analysis of the snap-action thermostats, it is obtained that the displacement of the ceramic rod and the bimetal sheet and the material of the thermostats have a great influence on the temperature drift of the thermostats, which provides theoretical guidance and reference for the subsequent use of vibration feeding of the snap-action thermostats.

To clarify the changing trend of compressor performance after the removal of the accumulator in the twin cylinder large rotor compressor, the original accumulator of the compressor was replaced with an F-type suction pipe for performance testing. Through experiments, it was found that the high-frequency performance deteriorated significantly when the F-type suction pipe replaced the original liquid reservoir. Therefore, focuses on studying the impact of the F-type suction pipe on the high-frequency performance of the compressor. Uses CFD simulation technology to discover that the main reason for the deterioration of high-frequency performance after replacing the reservoir with an F-type suction pipe is that the F-type suction pipe does not have the phenomenon of suction acceleration inside the original reservoir, and there is a phenomenon of gas reflux inside the pipe. At the same time, it was found that the diameter and length of the F-type suction pipe cannot alleviate the attenuation of high-frequency capability, but the purpose of alleviating high-frequency capability attenuation can be achieved by using a tapered pipe form to increase the suction flow rate or reduce the loss along the inside of the pipe.

The negative pressure distribution and flow rate at the inlet of the range hood have an important influence on the air performance, It is also important for the effect of smoking. Design a movable adjustment plate in the air duct of the range hood, the adjustment plate can be deflected to different positions. Through the analysis of the working principle of the model prototype, air performance test data analysis, and flow field simulation analysis, to study the effect of the regulating plate in different positions on the air performance and the flow field of the suction outlet. The results show that: when the adjustment plate is in the center position, the negative pressure distribution and flow velocity at the suction port are approximately the same. When the adjustment plate deflects to one side, as the deflection distance increases at the same rotational speed, the negative pressure distribution area and flow velocity of the suction port on the deflection side gradually decrease, the negative pressure distribution area and flow velocity of the suction port on the other side gradually increase.

One of the core frequency conversion control components of the frequency conversion refrigerator-the frequency conversion controller system consumes 75%~95% of the electric energy of the entire refrigerator. How to reduce the loss of the refrigerator frequency conversion controller and improve the conversion efficiency has attracted more and more attention. Analyzes the basic hardware structure of the traditional frequency conversion controller and analyzes the loss of different circuit parts in the frequency converter. The focus is on the loss of the bridge rectifier, the H6 inverter full bridge and the control loop. The detailed analysis and examples are given, and the optimization design scheme is proposed simultaneously. Compared with the traditional frequency conversion controller, the hardware loss of the frequency conversion controller is further reduced and the overall efficiency of the motor and frequency conversion controller is improved.

Based on the function of the accumulator in the system, this paper studies the performance change trend of the traditional high-back pressure rotary compressor (Abbreviations: models with reservoirs) after canceling the accumulator (Abbreviations: models without reservoirs). It also analyzes the reasons for the changes based on system parameters, and provides a feasibility analysis for the subsequent system architecture without an accumulator. Firstly, through single-unit simulation, it was found that under the single-unit GX working condition (8 ℃ suction superheat), the COP of the system with and without accumulator was basically the same. The result of the single-unit test showed that the COP difference between the two was less than 0.4%, which was basically consistent with the simulation data. However, through air conditioning system testing and reproduction on a single-unit suction dryness test bench, it was found that directly replacing the compressor without changing the system configuration, the non-accumulator model has an increased liquid-carrying capacity during suction and a energy efficiency decline of about 5.2%. By adjusting the throttling components and refrigerant charge, the non-accumulator model's overall performance can be maintained without decline (energy efficiency difference <0.5%), and the liquid-carrying capacity of the two is basically the same. Finally, after adjusting the system configuration, the maximum exhaust temperature was determined, and it was found that the temperature did not exceed 115 ℃, which meets the specifications of the compressor manual.

The drum support, an important part of drum washing machine, play an important role in the whole stiffness of inner drum system. However, severe cracks of the drum support are found in test and real usage, which leads to great risk to the reliability of the products, as well as negative effect on user safety. FEA (Finite Element Analysis) simulation is used to evaluate the mechanical behavior of drum support when suffer from working load. Based on the strength distribution, the design of drum support is optimized to achieve lower stress level. Finally, the stress results of both new design and original design are compared to demonstrate the optimized one could result in much lower stress level and minimized strength failure possibility.

：The paper mainly introduces the first generation technology of full-pipe preheating、the second generation technology of ECO energy-saving preheating and the third generation technology of precise preheating for gas water heaters to implement preheating function. The advantages and disadvantages of the above techniques are also introduced

The popularity of smart kitchens in our country is gradually increasing. Currently, most smart appliances are still in the stage of single product intelligence, and the compatibility between different smart appliances is poor, and different brand products cannot be interconnected. This article provides an overview of the history and current situation of smart kitchens, and studies and compares the relevant research progress of smart kitchens at home and abroad from three aspects: technological function improvement, industry development trends, kitchen environment, and user behavior of different groups. It analyzes the characteristics of diverse control entrances, high-end intelligent product systems, and scattered single product intelligence in smart kitchens, including user experience upgrading, design beautification and integration, and ecological development The development trend of smart kitchens is discussed in terms of data security.

Explored the research progress of refrigerator preservation technology, including three categories of methods: physical preservation, chemical preservation, and biological preservation. This article introduces traditional refrigerator preservation techniques, including the advantages and disadvantages of direct cooling and air-cooled refrigerators, as well as preservation techniques based on precise temperature control, partitioned storage, and gas control. In terms of new refrigerator preservation technology, cutting-edge technologies such as electric and magnetic field preservation technology, light preservation technology, and plasma preservation technology have been widely applied. Propose that the intelligentization of refrigerators should focus on food preservation, optimize human-machine interaction experience with Internet of Things technology, and provide scientific storage suggestions. The future refrigerator preservation technology will develop towards diversification and intelligence to meet consumers' demand for high-quality and safe food.

The display panel is used as the host computer in the refrigerator control system, and its operating system stores the logic control program; the control panel is used as the slave computer, which is responsible for the load drive; the display panel and the main control panel need continuous communication, and the display panel drives the control panel to control the refrigerator by sending communication data, so the communication system is the key factor to ensure the reliability of data transmission and control. Through the design of the communication system of the refrigerator, the communication protocol including guide code, communication head code, state data, control command, check code and end level is defined, which makes the communication process accurate and convenient.

As a vegetable fermented product, kimchi contains a large number of volatile compounds, which can easily lead to a strong kimchi ordor in the refrigerator during storage, affecting the consumer experience. Study analyzes the volatile odor components of common kimchi and studies the synergistic effect of ozone and metal oxides on the taste purification of kimchi. Using a single system kimchi refrigerator as a carrier, a kimchi taste purification module is output to solve the problem of kimchi taste purification in the refrigeration compartment of kimchi refrigerators. The research results indicate that the synergistic effect of ozone and metal oxides has a significant deodorizing effect on the aroma of kimchi, and the deodorizing effect can meet the sensory requirements of consumers.

With technological advancements, intelligent question answering has become crucial across various domains, with answer precision being a critical metric for evaluating these systems. Enhancing precision necessitates enhancing the accuracy of question similarity matching and the ranking of recall results. Building on current text vectorization techniques, experimental research has demonstrated that employing elastic hybrid matching and threshold segmentation processing of recall results can boost the precision of domain-specific question answering. Analysis of the experimental data from private domain Q&A on home appliances, we distill high-precision strategies for domain-specific question answering, offering theoretical insights to guide future intelligent question-answering approaches.

With the entry of smart homes into thousands of households, intelligent control algorithms for home appliances are increasingly becoming a hot topic in academic research. An important research direction of intelligent control algorithms is the optimization of control parameters that vary in real-time with dynamic factors such as the environment. In response to this issue, this article combines research progress in related fields and proposes a real-time adaptive algorithm based on (real-time) human feedback reinforcement learning and multi-objective parameter optimization algorithms. The feasibility and effectiveness of the algorithm were verified on the experimental data of air conditioning, and it also points out an optimization direction for intelligent air conditioning control. The contribution of this algorithm lies in: 1) fitting prediction algorithm, which first generates a fitting model for environmental factors such as room type and air conditioning parameters based on cluster analysis, and then predicts changes in air conditioning status based on the current air conditioning status. 2) Feedback reinforcement learning algorithm, using air conditioning status changes and user intervention as feedback, combined with real-time state (environment), real-time optimization decision model. 3) multi-objective parameter optimization algorithm, which searches for the optimal solution of control parameters for user experience, air conditioning energy conservation, and other multi-objective objectives.

With the widespread adoption of smart homes, users have gradually become accustomed to controlling multiple devices or functions through a single command. Traditional single-intent recognition dialogue systems cannot parse these complex commands, resulting in a stiff interaction process and poor user experience. To address this issue, Proposes a multi-module cascade multi-intent parsing dialogue system. This system first uses an intent segmentation model to split the user's multi-intent request into single-intent requests; then, it extracts the single-intent categories through a two-level classification model, including coarse-grained intent classification and fine-grained intent classification; finally, the dialogue management module completes the domain and slot information based on preset rules. The system's performance was evaluated using data from six types of home appliances. The basic command accuracy rate for each module and the overall system reached 100%, and the generalized command accuracy rate exceeded 96%, meeting the needs of practical applications.

Kitchen safety is one of the most talked about topics. Now the residential area is more and more modern, there will be some such as residents going out, aging gas pipelines, the elderly forgetfulness and other reasons caused by the kitchen dangerous situation, Designed to fuse infrared temperature sensor and Wi-Fi/4G module and other multi-level detection of the kitchen safety early warning module, the program through the use of non-contact infrared temperature sensor, DMOS human body presence module to monitor the kitchen personnel micro-action and fire temperature, combined with APP or cloud platform online real-time monitoring, to judge whether the kitchen state is safe, If there is an abnormal state, it will make corresponding prompts and reduce the incidence of home fires by notifying the user.

In recent years, Speech interaction technology has seen unprecedented development and application. In the field of air conditioners, Speech interaction has brought great convenience to consumers, freeing their hands and eliminating the need for remote controls. However, Speech interaction has always faced two pain points and challenges. First, offline Speech interaction has a limited set of local command words, generally around 100 words, making it difficult to cover the various expressions of consumers, often giving them the experience of “unresponsive Speech commands.” Second, while online Speech commands have a large command library and rich functionality, they require an internet connection and are limited by network speed and long data transmission paths, often leading to a “slow response” experience for users. Based on this, a new Speech interaction technology Speech interaction experience—Offline Speech Free Talk is proposed, combining the fast response rate of offline interaction with the rich command library of online interaction.

With the increasing attention to food preservation and dietary health, diverse food management methods have been applied to refrigerators and freezers, managing the entry and exit of ingredients and linking them with people's healthy diets. Food ingredient management can be achieved through image recognition, RFID, OCR, NFC, and voice technology, but each method has certain technical limitations, leading to limited application and promotion in products. NFC technology has advantages such as low cost, high recognition rate, and easy production, making it easier to promote and apply. A food ingredient management system based on NFC technology includes hardware design principles and software design processes. By using NFC food clips to manage food entry and exit, shelf life, nutrition management, etc., it can improve user experience and is suitable for both household and commercial use, with broad application prospects.

With the popularization of artificial intelligence, especially the rapid application and promotion of AIGC technology, it is bound to have a significant impact on intelligent interactive experiences. For instance, the original smart home scenes were preset and configured by various manufacturers, and users could only passively use and accept fixed combinations of smart home scenes. Moreover, most users are unfamiliar with the configuration methods of smart appliances, which fails to meet their needs for personalized smart scene customization. Focusing on the intelligent home field, and considering the various experiential problems users encounter while using whole house smart scenes, this method provides a solution that combines AIGC large model technology to achieve self-arrangement of whole house smart scenes. This allows users to easily customize smart scenes by either speaking a command or dragging devices on a screen, making it convenient and fast. This effectively addresses the long-standing issues of users not knowing how to use the systems and stores being reluctant to promote them. The ultimate goal is to create a new engine for whole house smart scene interaction, so that users' smart scene experiences are unique and innovative, frequently updated and tailored to individual needs.

OTA upgrade has become the basic function of smart appliances. The value of technological progress is to let OTA upgrade technology bring more benefits to manufacturers. The manufacturer manages the upgrade business through the OTA platform. In the production process of household appliances, the production system obtains the corresponding firmware program from the OTA platform according to the model of household appliances, and automatically completes the firmware writing and detection of household appliances. For the sold household appliances, users can upgrade them through mobile APP, device screen, voice interaction and other ways to realize the iteration of household appliance functions. The manufacturer's deployment of automatic OTA upgrades can quickly and widely solve potential problems with devices. The after-sales system can push upgrades to the problematic devices through the OTA platform based on user feedback, which can solve the problem in a timely and efficient manner. So, the application of OTA upgrade technology in household appliance production, user use stage and product after-sales service has important practical significance for manufacturers to improve production efficiency, iterate product functions, solve equipment problems and reduce after-sales costs.

With the enhancement of large-scale language model capabilities, how to handle long text understanding has become a key issue facing us. At present, there are strategies such as reducing the length of input or expanding the attention window size of models to alleviate the difficulty of understanding long texts. However, in specific knowledge domains, it is difficult to achieve the expected results of understanding long texts without fine-tuning using domain-specific data, which can easily lead to problems such as illusionary answers and missing key information. In order to address these issues, a model fine-tuning strategy that enhances the capture of contextual location information has been proposed, which uses efficient parameter fine-tuning to more accurately capture professional terms and concepts in the home appliance field, aggregating important details from long texts. Finally, by validating on the instruction manual dataset in the home appliance field, the fine-tuning method was evaluated using retrieval-enhanced generation technology for its ability to understand and generate long text content. This strategy improved accuracy by about 5% compared to baseline testing.

This project introduces generative artificial intelligence technology into smart home systems, enabling them to deeply understand language, life, and users, achieve more natural human-machine communication, more efficient intelligent control, and provide personalized scene customization based on user preferences. Intelligent control technology for a healthy living environment will study four typical life scenarios: intelligent sleep scenario, intelligent living scenario, intelligent bathing scene, and intelligent kitchen scenario. For each typical life scenario, the analysis of environmental factors and residents' physical and mental health factor indicators and their correlation, as well as the analysis of control strategies will be carried out in turn, combining the new generation of information technology such as the Internet of Things, cloud computing, mobile Internet, and big data. The smart home environment, smart bathing scene, and smart kitchen scenario will effectively combine home life such as intelligent control of home equipment, perception of home environment, perception of family health, perception of home security, information exchange, and consumer services, so as to achieve a low-carbon, healthy, intelligent, comfortable, and safe home lifestyle.

With the continuous development of 5G, Wi-Fi, and IoT technologies, networked air conditioners with only remote control and cloud-based scenario algorithms can no longer meet the user demand for a new generation of smart air conditioners. Sensing the home environment and the state of human activity in the space, so that the air conditioner to provide users with personalized control of the perception technology has become a current research hotspot. Driven by the integrated sensing technology, it is of great significance to synchronize the RF signal on the Wi-Fi module that meets the communication capability of the air conditioner to realize the sensing of space and human. In this study, a new module integrating Wi-Fi and radar is designed, which realizes accurate perception of the presence and distance of people in the room through signal processing, AI anti-interference algorithm and other technologies, and realizes intelligent function scenarios, such as wind avoiding blowing, no-wake interaction, proximity push, and unmanned energy-saving, through the results of the sensing. The air conditioner intelligent control technology based on the passive sensing of the integrated air conditioning through the perception of the environment, the human body and automatic decision-making, giving the air conditioner active service capabilities, significantly improving the user experience of the air conditioner.

Ordinary classroom lighting products and reading and table lamps for paper task are school supplies for children and adolescents, which play an important role in school classroom learning and home learning, so improving the visual lighting environment of schools and families is an effective measure for the prevention and control of myopia in children and adolescents. By expounding the current main quality and safety risks and market access policies of myopia prevention and control lighting products in children and adolescents, and analyzing the quality supervision and quality assurance measures of lighting products for myopia prevention and control in children and adolescents, practical countermeasures and suggestions are provided for improving the influence of conformity assessment of the performance of lighting products for myopia prevention and control in children and adolescents.

In order to optimize the stir-frying process of spinach, fixed-fire cooking mode, small fire to large fire cooking mode, large fire to small fire cooking mode were studied, the sensory, the cooking time, the retention ratio of Vitamin C were used as evaluation index. Results showed that: A4(8 level 2 min) cooking process had the least cooking time and the best sensory in fixed-fire cooking mode; B3(4 level 1.75 min turn to 6 level 1.25 min) cooking process had the best sensory in small fire to large fire cooking mode; C3(8 level 1 min turn to 2 level 3.25 min) cooking process had the best sensory in large fire to small fire cooking mode; among the best three kinds of cooking process, the sensory score had no significant difference(P>0.10) , the retention ratio of Vitamin C was C3(64.07%)>A4(63.05%)>B3(59.50%). Conclusion: the best nutritional stir-frying cooking process is C3, 8 level 1 min then turn to 2 level 3.25 min, considering the sensory, the cooking time, the retention ratio of Vitamin C.

Explored the impact of indoor environment on sleep quality, especially in hot environments where people commonly use devices such as air conditioning and fans to regulate indoor temperature, but the use of these devices increases energy consumption. Further exploration was conducted on the relationship between air flow and human thermal comfort, and it was pointed out that air flow can significantly enhance the process of heat loss in the human body, but the complexity of wind speed regulation strategies. In terms of research on thermal comfort during sleep in hot environments, sleep staging and sleep quality evaluation methods were analyzed, including multi-channel sleep monitoring systems (PSG), body movement recorders, and survey questionnaires. It is crucial to build a human physiological heat regulation model and a thermal sensation prediction and evaluation model specifically for sleep states, and to explore the possibility of using smart home appliances and smart homes to construct an intelligent sleep environment control system, in order to reduce energy consumption and improve the comfort of the living environment.

With the continuous upgrading of air conditioning usage demand, people's attention to the comfort and energy-saving performance of room air conditioners and other equipment is also increasing. Six key indicators for indoor thermal comfort evaluation are integrated: average thermal sensation index, thermal sensation voting, effective temperature, standard effective temperature, air distribution characteristic indicators, and thermal comfort voting model. These indicators are divided into two categories: subjective evaluation models for thermal comfort and objective evaluation models for thermal comfort. The objective evaluation model can be calculated through specific formulas, while the subjective evaluation model relies on people's voting results. However, neither of these models can currently be directly applied to the control of air conditioning systems. To address this issue, two approaches are summarized to solving it. The first approach is to simplify the objective evaluation model for thermal comfort, so that the air conditioning system can be effectively controlled based on the simplified model. The second approach is to use a subjective and objective evaluation model for thermal comfort to establish a machine learning model. This model will be driven by the data collected by sensors and the image data obtained by thermal imaging technology to achieve accurate control of the air conditioning system. Through these two methods, the comfort and energy-saving performance of the air conditioning system can be significantly improved, meeting people's pursuit of high-quality life.

With the popularization and application of air conditioning, the comfort of air conditioning is the most concerned issue for users. And sleep scenes are the most comfortable scenarios for users to experience. In the past, air conditioners were generally set with a fixed sleep curve for temperature adjustment in sleep scenarios. However, due to the inability to monitor user sleep information feedback, it was not possible to flexibly adjust the air conditioner to meet the needs of various different users. There are generally two methods for monitoring sleep: contact based and non-contact based. Contact based sleep monitoring devices can cause discomfort during sleep, and this article studies non-contact sleep monitoring methods. This article elaborates on the use of non-contact millimeter wave radar to detect human presence and sleep information, combined with the application scenarios of air conditioning, to achieve precise temperature control, intelligent fresh air, intelligent wind speed and other controls, creating a comfortable sleeping environment for users and improving their experience.

With the improvement of modern living standards, air-conditioning has become an indispensable electrical device in home and office environments. However, after a long period of operation of the air conditioner, a large amount of dust, bacteria and dirt will accumulate on the condenser, which not only affects the cooling efficiency and reliability of the components, but also have an adverse effect on indoor air quality. Therefore, the self-cleaning function of air-conditioner condenser is particularly important, For the effect of air-conditioning condenser self-cleaning using the method of comparative testing, after six working conditions test to determine the optimisation scheme to enhance the operating frequency of the outer unit frost stage, while the implementation of the inner tube overload limit frequency, the programme significantly improves the thickness of the outer unit frost, optimising the effect of self-cleaning.

This study designed an algorithm based on infrared temperature measurement technology to detect dry burning in integrated stoves and take appropriate actions. Experimental results validated the efficiency and reliability of this algorithm, demonstrating that it can accurately distinguish between normal cooking and dry burning under different pot materials and heat settings by setting temperature thresholds and temperature change rates. Compared to traditional methods, it significantly enhances detection accuracy and response speed, reducing the possibility of false alarms. This provides a safer and more convenient solution for dry-burning prevention in integrated stoves. In the future, integrating data from multiple sensors could further optimize detection accuracy, ensuring user safety and enhancing the user experience.

In the context of the big data era, the traditional home appliance industry is undergoing a historical transformation of interweaving and integrating new technologies and business needs. Through statistical analysis of a large amount of user refrigerator data, rules for extracting time temperature difference big data indicators and defrosting decision rules have been developed to indirectly identify the degree of evaporator frost, and initiate defrosting when refrigerator performance begins to deteriorate. With the help of big data technology, a time temperature difference big data intelligent defrosting system has been deployed on the big data platform. A standard temperature difference value has been established for each defrosting cycle of each refrigerator to make judgments and decisions. Through comparison before and after optimization, the defrosting cycle has been significantly extended after optimization, which brings multiple performance improvements to the refrigerator.

China's cabinet and electrical appliance market has gone through stages of supply shortage, supply-demand balance, and incentive competition, and the industry has gradually developed and matured. An overview of the development history of cabinets, kitchen appliances, and integrated kitchens both domestically and internationally; Analyzed the current situation and existing problems of the cabinet and electrical appliance industry, in the context of the country's strong promotion of integrated development in the home appliance industry; Proposed ways to enhance the synchronous development of cabinets and kitchen appliances from the aspects of design, function, installation, and after-sales service, and promote the integrated and coordinated development of cabinets and kitchen appliances; Looking ahead to the development trend of integrated cabinet and electrical appliances under the background of upgrading consumer consumption and differentiation of consumer groups.

As a household appliance in the product introduction stage, household kitchen air conditioner holds a promising market outlook; however, the exploration of user demands remains inadequate. To design products that better meet the needs of users, the author conducts innovative design research on household kitchen air conditioning by adopting the customer journey map and the TRIZ theory. Firstly, the customer journey map is drawn based on desk research, questionnaire surveys, and user interviews, and the user needs and opportunity points in the user journey map are analyzed using the peak-end law. Secondly, the problem is investigated by employing the Achshuler contradiction matrix of the TRIZ theory and other tools, and solutions are proposed. Finally, it innovatively designed the operation mode and voice control function of household kitchen air conditioners in various use scenarios, and created the easy-to-clean functional attribute. This provides design ideas and references for household kitchen air conditioning in the future.

Users are accustomed to switching off the heat pump unit during the day and switching on the heat pump unit at night during the transitional season when heating is required, and such usage habits make the study of the frequency control strategy of the heat pump switch-on phase particularly important. In order to study the difference between the room temperature rise effect and power consumption under different switch-on frequencies, found that under the same test conditions, by comparing the operating effect of the unit under the initial frequencies of 80 Hz and 68 Hz, the indoor temperature rise effect of the two schemes is comparable, but the power consumption of the 68 Hz operating frequency is reduced by 14% compared with that of 80 Hz in 1 h. Through the time-by-time data comparison, it was found that the water temperature grows too fast is the main reason for the high energy consumption of high-frequency start-up operation, which leads to the conclusion that the frequency control in the start-up phase needs to be correlated with the rate of water temperature growth. The results of this experiment can provide a reference for the optimisation of the start-up frequency control strategy of heat pump units.

The after-sales maintenance data is a critical material for learning the reliability performance of household appliances on user end. Calculating the market reliability at specific periods by using after-sale maintenance data and sales data, guidance can be generated to assist the improvement of after-sale service and product development. Influenced by numerous failure modes, delayed training and human error in judgment, after-sale hotline personnels or maintenance personnels may make mistakes in the recording of failure modes, and then affect the reliability analysis of each failure mode. This article introduces a methodology for estimating product reliability in market, this method based on after-sale repair data of air treatment system, uses text analysis technology such as jieba word-cut, TF-IDF and clustering to increase the accuracy of failure classification, and applies Reliability Block Diagram (RBD) to the reliability analysis of each failure mode, part, and system.

The National Standardization Administration issued a new mandatory standard GB 4343.1-2024 Electromagnetic compatibility requirements for household appliances, electric tools and similar apparatus Part 1: Emission on May 28, 2024. The new version has reorganized the entire text, adding specific testing requirements for vacuum cleaners and robots cleaner, methods and limits for conducting disturbance using current probes at auxiliary ports, clarifying technical requirements for measurements with built-in lighting equipment, and expanding the radiated measurement frequency range to 6 GHz. This standard is based on the actual situation in China and the characteristics of household appliances, modified to adopt the international standard CISPR 14-1:2020 to make the standard applicability, compliance, and timeliness. Further promote international trade and enhance the safety and electromagnetic compatibility of products.

In recent years, with the advantages of short cycle, simple test operation and flexibility compared with ability verification, measurement audit has been favored by laboratories. With the limitation of measurement audit project, many interdisciplinary laboratories put forward the need to add standards, which is becoming more and more obvious. How to judge whether the standard can be added is also our current important work. Taking the high and low temperature test of measurement audit project as an example, this paper summarizes the requirements for adding standards put forward by participating laboratories, and analyzes in detail whether adopting different standards has an impact on the results. I hope it will be helpful to the work of competency verification providers.

The heat pump technology is applied to the products of the water dispenser, and the heat and cold capacity of the heat exchanger are used to make water at a specific temperature, so as to improve the energy utilization rate and achieve the effect of energy saving and emission reduction. In this paper, a heat pump type water dispenser with heat production of 1026 W and COP of 2.02 is designed by combining water tank and heat exchanger, by which heating water temperature can reach 72 ℃. The economic benefits of the heat pump type water dispenser are analyzed, and the improvement scheme of the heat pump type water dispenser is provided, which provides theoretical and data support for replacing the electronic ice bladder and realizing large energy saving.

The global economic development and changes in the domestic economic situation have put forward new strategic requirements for China's standardization work. As an important component of the standardization system, standard samples have been widely used in fields such as quantity traceability, quality control, capability verification, and testing method confirmation. In the context of deepening standardization reform, promoting the improvement and high-quality development of standard samples should fully leverage the decisive role of the market, analyze the current development status of standard samples in China, and study the development strategies of standard samples. Comprehensively optimize the internal and external development environment of standard samples, and promote the improvement of the quality and competitiveness of standard samples.

In view of the measurement of power input of waste food processor, there are great differences between different testing institutions, which brings great confusion to production enterprises. Through the research on the test method of power input of waste food processor, the main factors affecting its power measurement value are analyzed and determined, and the technical specifications for assisting the power input test in the new national standard GB/T 4706.49—2024 are formulated, thus improving the consistency of the test, providing reference for other testing institutions to test power input, guiding the accuracy test of power input , and helping to promote the revision of international standards.

Heat transfer sound has been an unavoidable problem in the development of air conditioning, and the current common practice is to set up a simple expansion muffler in the pipeline of the outer unit to control it. However, due to the physical limitations of simple expansion muffler, it is impossible to achieve the effective unification of high noise reduction and small volume. In order to solve this contradiction, the finite element method was firstly applied to analyze the influence of relevant parameters on the muffling performance of partial perforated straight-through pipe mufflers, and it was found that the perforated section length, location and perforation rate had a significant influence on the muffling performance. These laws were then applied to optimize an air-conditioning muffler, achieving a 43.9% reduction in the volume of the muffler material without weakening or exceeding the original muffler's silencing performance. Finally, the heat transfer sound test of the whole machine shows that the optimized partial perforated straight-through pipe muffler is comparable to the original muffler in quiet wind gear, with an advantage in the low wind gear.

With the continuous reduction of air conditioning noise, sound quality issues have become a new important research direction for air conditioners. Through multiple comparative studies, Establishes a subjective sound quality evaluation method based on the reference scoring method, and the timeliness and accuracy of the evaluation results are higher. Through the sensitivity analysis of objective evaluation parameters of sound quality such as A-weighted sound level, loudness, sharpness, roughness, speech intelligibility, and prominence ratio, based on the multiple linear regression analysis method, an objective evaluation model of sound quality is established. The conformity between the objective evaluation model of sound quality and the subjective evaluation results of sound quality exceeds 90%.

The AC motor has the advantages of simple structure, high reliability and low cost, and is widely used in the range hood products. However, due to the inherent properties of the AC motor, many range hood products equipped with the AC motor appear 100 Hz and 200 Hz motor resonance “buzz”, which will seriously affect the customer experience and reduce product quality. Through the combination of dichotomy and spectrum analysis, rapid qualitative and quantitative analysis of the abnormal sound, through the combination of motor shock pad matching and sheet metal structure optimization, effectively eliminate the kitchen hood motor sound.

When a certain dehumidifier compressor is shut down, the stress in the suction pipe exceeds the enterprise standard limit. This article uses a combination of simulation and testing methods to study the mechanism of the high stress in the suction pipe during compressor shutdown. Transient simulation analysis is used to analyze the stress in the suction pipe during compressor shutdown. The maximum position of the simulation stress is basically consistent with the test, and the maximum error is controlled within 10%. The position of the pipeline damper is optimized, and the problem of excessive shutdown stress is solved, shortening the development cycle and improving design efficiency.

To enhance the NVH (Noise, Vibration, Harshness) performance of the range hood, reduce the radiated noise generated by the vibration of the main box sheet metal structure, rubber damping materials are pasted on the main box sheet metal structure of the range hood to achieve the effect of vibration reduction and noise reduction. At the same time, it also has a good effect on improving the sound quality characteristics of the range hood. Through the analysis of the vibration and noise test data of different rubber damping material schemes, rubber damping materials can play a role in reducing vibration and noise and improving sound quality. The effect is related to the pasting position, the material loss factor properties, and the thickness. Under various working conditions, the noise value is reduced by up to 0.51 decibels, the vibration amount is reduced by more than 65%, the loudness is reduced by up to 0.32 sones, and the sharpness value changes little overall. For reducing the mid-low frequency noise under the mid-low speed working conditions of the range hood, pasting rubber damping materials at the appropriate position of the range hood has a good effect.

By extracting the volume of the internal cavity of the compressor, the cavity modal frequency is calculated, which is used as the key muffler frequency band. The adjustment of the muffler is designed according to the basic muffler structure principle, and the detailed structure of the muffler is optimized by Virtual Lab simulation calculation. Finally, the optimization effect of target frequency noise is determined through the muffler transmission loss test device and compressor noise, so as to achieve the purpose of optimizing the amplitude of the key frequency band of the compressor.

The back pressure of the air duct of the public flue exhaust system is complex and changes greatly, and the traditional range hood cannot automatically match the optimal working mode. By designing an effective air system of the range hood to effectively solve the impact of the back pressure of the air duct on the effect of the range hood from three aspects: algorithm, sensor and air duct, and at the same time effectively reduce the noise during the use of the range hood.

A noise reduction material with both performance and cost is selected to improve the noise reduction performance of the whole machine without reducing the air performance. Compared with the existing noise reduction technologies in household appliance industry, the importance of noise reduction of range hood is expounded, and the noise reduction principle of the main noise sources and absorbing materials of range hood is analyzed. Ordinary felt and two-component cotton were selected as the research objects to test the sound absorption coefficient of the two materials and the noise reduction effect of the two materials on the whole machine. Through the test experiment, the two-component sound absorption cotton showed a good sound absorption effect. At the same time, adding a rubber layer on the surface of the two-component cotton could further improve the noise reduction effect. The research content is of great significance to promote the development of noise reduction of range hood.

The reliability of the main control board is very important to the normal operation of the air conditioning machine, and the reliability of the main control board is greatly tested by various vibration and shock excitation, so its anti-vibration ability should be fully verified when designing the main control board. The failure mechanism of the bridge pin breaking and falling off occurred in the sweep frequency experiment of the vibration table of the main control board is studied by combining CAE simulation analysis and experiment test. Then, an optimization scheme is proposed to isolate vibration transmission by adding screws. Finally, the effectiveness of the improved scheme is verified by simulation and experiment.

When the air conditioner is opened, due to the material characteristics of the parts, the effect of thermal expansion and cold contraction will occur, and the parts will change in length and volume, especially in the air conditioner outlet position, the temperature difference is relatively large. When the parts undergo thermal expansion and contraction, the size of the parts will change and produce a certain displacement, resulting in the abnormal noise of “clicking” in the air conditioner. Through the analysis of abnormal noise, in the cooling and heating of air conditioning, the force of parts after deformation is unbalanced, and the dynamic friction force between parts is larger than the static friction force when thermal expansion and cold contraction occur, resulting in sliding friction and sound. In order to optimize and improve the abnormal noise of this kind of air conditioning structure, improved the force between the parts by optimizing the structure, so that the force balance between the parts after installation of the whole machine was achieved, so as to reduce the static friction between the parts and improve the stick-slip friction, so as to optimize the abnormal noise of the structure generated by the air conditioning. The noise experience of the whole machine was remarkable, and the noise test was qualified.

The mechanism of refrigerant flow sound in commercial air conditioning was studied through a combination of experiments and simulations. It is found that there is a cavity resonance phenomenon between the electronic expansion valve B tube and the reducing joint in the cavity area. Based on the distribution characteristics of acoustic cavity modes, an improvement measure for the integration of reducing joints was proposed, which improved the key frequency band of refrigerant flow sound by more than 3 dB (A) and significantly improved the listening experience.

As important equipment for air conditioning, the noise control level of the air conditioning system is one of the key factors in evaluating its quality. Therefore, in-depth research on the noise problem of air conditioning systems is particularly important. The noise, airflow, and whistling sounds that occur during the cooling and heating process of heat pump heating mechanisms are focused on by this article. Through experimental analysis, the problem is identified and optimization solutions are proposed. The results indicate that the three-way variable diameter at the subcooled outlet and the structure of the electronic expansion valve is the main causes of airflow and whistling sounds; The main valve adopts a straight through type, and adjusting the diameter of the subcooled outlet main pipe to the same diameter as the three-way valve (diameter 7) can significantly reduce the occurrence of airflow and whistling sounds. This study has certain reference value for solving problems such as airflow noise and whistling sound in air conditioning systems, as well as optimizing noise reduction design in air conditioning systems.