In response to the current problem of high closed water temperature and poor user experience in instantaneous heating aluminum casting heating elements, a CFD model was established to study different performance parameters such as heating speed, closed water temperature rise, flow rate inside the bypass tube, and heating temperature field of the heating element under 2 mm, 3 mm, and 4 mm bypass tube diameters and 1 and 3 bend tube structures. The results of the study show that adding a bypass premix device to the heating element can effectively reduce the temperature rise of the heating element and improve the user's bathing experience. However, adding a bypass premix device will increase the surface temperature of the heating element and increase the heating speed of the heating element. In addition, it was found that reducing the diameter of the bypass pipe has a more significant impact on the flow rate changes inside the pipe than changing the structure of the bypass bend.

At present, the outdoor unit of air conditioning is usually installed in the equipment room of office buildings or high-rise pits, which is close to the user. Excessive operating noise has a direct impact on the user's work and life, and will also cause user complaints and increase the company's operation and maintenance costs. The high aeroacoustics wind noise of the whole machine is one of the main reasons for the high noise of air conditioning operation.Constructs an improved fan-duct coupling method for drag reduction and noise suppression including shape optimization of middle baffle and drag reduction of outlet grills and so on based on the combination of test and simulation, aiming to solve the currently existing problems such as high aerodynamic drag and hyper aerodynamic noises. According to the sample’s air volume and noise experiments reports, the aerodynamic drag and noise of the as-designed machine sample was reduced by 5 Pa and 1.4 dB(A) under the same test conditions, respectively. The optimization analysis results have a certain guiding effect on the efficiency improvement and noise reduction design of the fan duct in the air conditioner outdoor unit.

Because the lower basket is as the frequently used component for dishwasher users, it is necessary to enhance the users' operating experience when pushing and pulling the lower basket in dishwashers. Based on the analysis of the current single-sided force situation, a wheel frame roller structure with the double-sided force situation is proposed. By comparing the difference of force analysis between the conventional roller structure and the wheel frame roller structure, and combining the simulation analysis results of basket components with two different roller structures, the effects of the two structures to control deformation were obtained, and the improvement to the theoretical service life of baskets with using the wheel frame roller structure can be preliminarily evaluated. Furthermore, the multidimensional evaluations were proceeded for the moving smoothness of rollers and the push-pull smoothness of lower baskets, especially considering the different load states in the baskets. Through the push-pull test results of two roller structures and the users experience test, the improvement effect by using the wheel frame roller structure is verified. At the same time, the reliability of the wheel frame roller structure was also verified through the push-pull test. In summary, there provides theoretical reference and practical feasible methods for optimizing the push-pull experience of dishwasher baskets.

Due to the energy-saving trend of inverter air conditioners, the speed of compressors is getting lower and lower. At low speeds, sliding vane sounds are prone to occur, which seriously affects their performance and comfort. To explore the root cause of the sliding vane sound, this paper analyzes the second-order motion and lubrication characteristics of the sliding vane and establishes a sliding vane friction dynamics model for the roller compressor. The generation mechanism and influencing factors of the sliding vane sound are theoretically analyzed and experimentally verified. The results show that the low-frequency sliding vane sound is caused by the large friction force, which makes the gas force at the back of the vane insufficient to maintain the contact between the vane tip and the roller, and it usually occurs during the exhaust stage under low pressure difference conditions. The main influencing factors are the eccentricity, friction coefficient, and vane length. Finally, the friction force is reduced by adopting the offset double vertical groove and reducing the surface roughness. The experimental test shows no abnormal noise like "dada", and the low-frequency sliding vane sound is significantly suppressed, verifying the correctness of the model and providing a reference for the performance and noise design of the compressor at low speeds.

At present, the technology maturity of air conditioning BLDC (Brushless Direct Current Motor) motors is relatively high, and there is serious homogenization in the industry. At the same time, customers have a demand for further cost reduction and miniaturization of motors has increased. Therefore, an external rotor topology motor is proposed and its optimization design is carried out based on Maxwell finite element simulation software. Firstly, from a performance perspective, a comparative analysis was conducted on different slot pole combinations; Then, with cost and performance as optimization objectives, optimization analysis was conducted on the aspect ratio of the motor, rotor yoke thickness, permanent magnet thickness, stator tooth width, yoke width, pole shoe thickness, and slot width, and optimization solutions were obtained; Finally, the optimization plan was validated through sample preparation. The results show that under the same output power, the optimized outer rotor scheme reduces electromagnetic costs by 19% and volume by 16% compared to the inner rotor scheme. At the same time, the measured data of the prototype is basically consistent with the simulation data, which verifies the accuracy of the simulation. Overall, for air conditioning BLDC motors, the outer rotor topology has lower cost and higher power density compared to existing inner rotor solutions.

Since the release of DeepSeek in January 2025, it has attracted the attention of domestic and foreign technology companies such as Amazon, Microsoft, Baidu, and Tencent, as well as leading home appliance companies like Haier, Midea, Hisense, and TCL, due to its strong reasoning ability, innovative technologies such as the Mixture of Experts (MoE) and gating mechanisms, and the reduction in computing power requirements and training costs. This has enabled ordinary people to enjoy the convenience brought by DeepSeek to their lives and work, laying the foundation for users to drive the intelligent home appliance agents based on the DeepSeek reasoning model, and providing a new solution to the problems of poor user experience and unsatisfactory market sales of smart home appliances. Therefore, studies the operation mechanism of DeepSeek and the architecture of intelligent home appliance agents, and explores the technical routes and applications of intelligent home appliance agents based on the DeepSeek reasoning model from aspects such as problem boundaries, knowledge base construction, and human-computer interaction interfaces. It is expected to accelerate the application of DeepSeek in the smart home appliance industry, enhance the satisfation of user experience, and provide a new idea for the intelligent transformation of the home appliance industry.

Although machine learning and artificial intelligence technologies have been applied to fault diagnosis in smart home appliances, they still face challenges such as data coupling between sensors, dynamic changes in data, and difficulty in obtaining fault data. To address the above issues, on intelligent famlt detection method for home appliances based on dual graph attention network and interval prediction is proposed. By simultaneously modeling the relationships between sensors and the dynamic patterns of data in time series, fault diagnosis can be performed through unsupervised learning, which does not require fault data for network training. This method achieved an accuracy of 92.3% in classifying normal and fault data on a real-world household air conditioning operation dataset. It maintained high accuracy even under noise interference, providing an effective and precise technical approach for enhancing fault diagnosis of smart home appliances. It is of great significance for promoting the development of smart home technology.

Dry cleaning and water washing have a good complementary effect in the washing and care of clothes. Dry cleaning technology has obvious care advantages over water cleaning, but due to the complex and large structure of traditional dry cleaning machines, the health hazards of dry cleaning agents are high, which limits the domestication of dry cleaning technology. An oily gel material was prepared combined with a household dryer to remove oily stains, which can release detergent and dissolve stains. The experiment shows that under the factors of the mechanical force of the dryer, temperature and other factors, the dry cleaning technology has a removal rate of over 90% for oily stains, a wool shrinkage rate of less than 1.0%, and a real silk color fastness of 4.3 in the cloth drier.

The stain removal on the surface of cellulose fiber fabric is an important index to evaluate the performance of washing equipment. Changes in stain removal processes and removal mechanisms as a theoretical basis for improving the cleaning performance of washing equipment, combining relevant research reports to discuss the factors affecting stain removal and the mechanisms of these factors. It summarizes the relevant theories of stain removal and the interrelationships between various factors, explaining the role of these theories in the decontamination process of cellulose fabric surfaces. Finally, scientifically and systematically suggested to use cellulose derivatives as surfactants, auxiliary agents, or finishing agents in the detergent formulation to promote the decontamination effect of cellulose surfaces.

Steaming is one of the commonly used and healthiest cooking methods. Compared with the atmospheric pressure steaming, high-pressure steaming has higher efficiency of heat and mass transfer. Took purple potatoes as a typical material to study the effect of high-pressure steaming(110 kPa) on cooking quality of purple potatoes, taking the atmospheric pressure steaming as control. The results showed that purple potatoes could reach the best mature state after steaming 25 minutes at atmospheric pressure or steaming 20 minutes at 110 kPa. On this condition, purple potatoes steamed at high-pressure had richer aroma, softer taste, and more uniform texture compared with those steamed at atmospheric pressure. Moreover, high-pressure steaming was conducive to the higher retention of anthocyanins, with an increasing retention rate of 76.12%. In summary, high-pressure steaming had the characteristics of faster cooking speed, better edible quality and higher nutrient retention, which could provide the practical basis for the product and function development of high-pressure steaming.

The effect of roasting coffee beans by steaming oven was verified through the research and comparative experiment. The results show that the best process parameters for roasting coffee beans in a steam oven are as follows: 100 g green coffee beans, three-stage roasting, fan speed 1500 r/min, 180 ℃/6 min; 200 ℃/12 min; 230 ℃/6 min. The coffee roasted under this cooking condition can achieve similar quality to the finished coffee sold on the market, and provide a new application scenario for the rotary roasting cage accessories, increase the value of the accessories, but also provide a simple solution for users to roast coffee beans at home, and provide a new roasting solution for the market.

To address customers’ feedback regarding the lack of crispiness in food cooked with air-frying function of the combi steam oven and the significant difference compared to deep-fried food, the air-frying function is improved to enhance its taste and nutritional performance. By studying the crispness of deep-fried French fries as the target crispness; researching the effects of different fan speeds, steam addition, and the crispness of different ingredients on the air-frying performance; additionally, researching the advantages of steam-added air-frying for meat in enhancing fat removal and meat tenderness. Ultimately, an air-frying function for combi steam ovens can be achieved that not only improves sensory quality but also has health benefits, bringing users a better taste and healthier cooking experience.

Typhoon weather poses challenges to the operation of inverter air conditioners. On one hand, before the air conditioner is turned on, the outdoor fan may be affected by the typhoon, causing it to rotate forward or backward, which could lead to fan startup failure. On the other hand, a sudden typhoon during operation can cause drastic changes in the load torque of the outdoor fan, potentially triggering a speed-control fault and shutdown. For the issue of the operation of the outdoor direct-current (DC) fan of an inverter air conditioner during typhoon weather, an initial speed detection method based on a flux observer is proposed, which allows the system to enter different startup modes according to different initial speeds. An innovative startup control method under initial reverse rotation conditions is developed to improve the success rate of DC fan startups. The speed loop controller is improved to enhance resistance to typhoon load disturbances. The effectiveness of the anti-typhoon control strategy is verified through experiment platform consisting of inverter air conditioner and typhoon simulator.

Noise is an important sensory indicator of refrigerator products and also a key concern for consumers. If the refrigerator has high noise or abnormal noise, it may cause consumer complaints. The evaluate of the noise during the pull down stage of a frost-free side-by-side refrigerator by monitoring and recording the noise test process throughout the entire period, combined with methods such as ear sensing and near-field microphone fixed-point monitoring. It is found that the refrigerator has problems such as high compressor noise, obvious resonance of connecting pipes, and abnormal noise during the damper opening stage during the pull down stage. Through the implementation of the compressor step-up speed control, the connection pipe wrapped with soft XPE foam, and the gap between the damper and the air duct foam increased, the peak noise of the pull down stage was reduced from 45 dB(A) to 37 dB(A), and a series of problems such as the resonance noise of the connection pipe and the abnormal noise of the damper opening were eliminated. The noise in the pull down stage of the whole machine has been significantly improved, and the user's experience has been greatly improved.

Thin range hoods adopt exist with dual outlets design, one of which is in poor working condition. In order to study the vibration of the machine under poor working condition, vibration tests were carried out on the original machine. The test results show that the wind volume of the whole machine increased, the vibration velocity value significantly increased, reaching a maximum of 9.32 mm/s. According to the structural characteristics of the machine and the pattern of vibration changes, the root cause of the problem was identified as insufficient rigidity of the motor mounting plane, which failed to block the disturbances from the impeller from being transmitted to the machine case, resulting in machine vibration. In view of this issue, the vibration problem of the whole machine was simplified as a rigidity design issue related to the presence of a large notched plane. Longitudinal stiffeners, circumferential stiffeners, and other combinations of stiffener designs were created. The effects of different stiffeners on rigidity were evaluated through static simulations, which showed that circumferential stiffeners improved rigidity more effectively than radial stiffeners. The optimal design was selected for experimental validation, demonstrating that the maximum vibration speed of the whole machine was reduced from 9.32 mm/s to 2.97 mm/s, significantly improving the machine's vibration problem.

The low-temperature heating capacity test is a necessary practical test item in the energy efficiency evaluation of heat pump room air conditioners, and it has a crucial impact on determining the energy efficiency rating of the air conditioner. During the testing process, the outdoor unit of the air conditioner may experience transient operation due to frosting and defrosting, posing higher demands on the accuracy of test results. This study investigates three commonly used measures in the laboratory to determine the start and end state points of the defrosting process of the air conditioner: monitoring power value of the tested air conditioner, four-way valve action signals, and outlet static pressure. The study analyzes and compares the cycle period, heating capacity, power consumption, and energy efficiency ratio(EER)measured by different methods, to improve the operational rationality and reliability of the heating capacity test of air conditioners. Experimental findings reveal that compared to using four-way valve actuation signals for judgment, the use of operating power and outlet static pressure as criteria results in a negative deviation of-4.8% and a positive deviation of +3.8% in measured low-temperature heating capacity, respectively. These deviations subsequently impact the calculation of the annual performance factor(APF). Given that four-way valve actuation is intimately tied to the internal control strategies and real-time operating status of the air conditioner, while this method for defrosting process determination is more complex operationally than the other two, it offers greater advantages in enhancing the operational rationality and result reliability of the heating capacity test for air conditioners.

To reduce the power consumption of air conditioning when using fresh air function, a technical scheme using heat pump technology for heat recovery of exhaust air is proposed. A 3-horsepower air duct unit is selected as the research object. Using Midea's self-developed refrigeration system simulation software MCOOL under Nanjing city meteorological conditions, theoretical analysis is carried out on its energy-saving effect and economic indicators. The results show that compared with the basic air duct unit, for cooling and heating conditions, under the same capacity, exhaust heat recovery technology can reduce the compressor frequency by 3 Hz~15 Hz and 1 Hz~5 Hz respectively. The new technology can save 330.5 kW·h of electricity in the cooling season and 304.6 kW·h of electricity in the heating season, with an annual electricity savings of up to 635.1 kW·h, and the energy-saving effect is significant. The additional cost of the exhaust module is estimated, and the return on investment (ROI) is calculated to reach 83.2%, indicating a high economic value.

R1234yf and R1234ze(E) are new environmentally friendly refrigeration working substances in heat pump hot water systems, but they are still less applied in heat pump water heater with storage tank. Therefore, the operating characteristics of R1234yf and R1234ze (E) in a storage-type heat pump water heater system was investigated. The effects of R1234yf charge amount and operating ambient temperature on its operating characteristics were experimentally studied. For the heat pump water heater system established in this study, the optimal R1234yf charge amount is 1000 g, with heating capacity of 5170 W and a heating COP of 4.24. Within the allowable range of the heat pump, higher ambient temperature leads to greater heating capacity and higher heating COP. A comparative study on the differences in operating characteristics between R1234yf and R1234ze (E) showed that R1234ze (E) has lower operating exhaust pressure and temperature when used in the heat pump water heater system, and has good application potential in high water temperature conditions.

Taking the air enthalpy method as an example to measure the rated cooling capacity of room air conditioners, this paper analyzes the calculation formulas for the air moisture content, saturated water vapor partial pressure, specific heat, and other thermal properties on the indoor supply and return sides, as well as the measurement model for the rated cooling capacity. By analyzing the measurement model of customized cooling capacity, the input of uncertainty was determined, and the uncertainty of customized cooling capacity is evaluated using GUM method and adaptive MCM method, respectively. After comparison and verification, the results obtained by the two methods are basically consistent. The adaptive MCM method can greatly simplify the calculation of partial derivatives and sensitivity coefficients for various uncertainty components in the uncertainty assessment process of rated cooling capacity, while also ensuring the calculation accuracy of rated cooling capacity uncertainty.