Abstract:The development trend of refrigerator towards thin foam layer and large volume has aggravated the problem of poor foam filling.It is an effective way to optimize the density distribution by regulating the foam flow with the diversion structure.However,it is difficult to directly observe the foaming process,resulting in the determination of the scheme relying on repeated tests,which is inefficient and costly.The simulation method can be used to design the scheme in the product design stage,improve the R&D efficiency and reduce the test cost.Firstly,a foaming simulation model of a box with upper and lower structure was built under the condition of diversion,and the error between the measured and simulated average density in each area of the box was less than 5％.Furthermore,the simulation and optimization of the diversion structure are carried out.Finally,through experimental verification,the foam density range of the optimized scheme was reduced by 10％,and the foam density uniformity was significantly improved.

Abstract:To systematically evaluate the influence of key parameters of the multi-ion module in the floor-standing air conditioner on the negative ion release characteristics and particulate matter purification efficiency,conduct multi-dimensional optimization research on the structure,performance,hardware design,and user interaction of the emitter quantity,probe spacing,grounding method,and dual air duct structure.The results show that when the module is configured with 6 groups of negative ion emitters and each group of emitters is connected in parallel with 3 carbon brushes,the particulate matter removal rate reaches the highest;when the carbon brush spacing is controlled within the range of 15 mm to 20 mm,the negative ion number concentration reaches a peak;grounding the plastic shell through a wire can effectively suppress charge accumulation and increase the negative ion escape rate.Under the synergistic effect of the dual air duct flow field,the theoretical coverage area of the negative ion concentration is approximately 45 m2.After testing by a third-party authoritative institution,the PM2 5 removal rate of the multi-ion module within 2 hours is greater than 99％.The research results provide a quantitative basis for the engineering design of high-efficiency air purification air conditioners with negative ion modules.

Abstract:Amid escalating market competition in the air conditioning industry,the optimization of tube-fin heat exchanger design,a critical component in mobile air conditioning systems,has emerged as a central area of research within the sector.Based on numerical simulations,introduces a novel design approach for condenser fins.Through systematic testing of individual heat exchangers and comprehensive validation using full-scale machine experiments,it is demonstrated that,compared to the original design,the implementation of the new fin configuration leads to a 3.5％to 4.2％reduction in the heat exchange capacity of individual components.However,the overall system performance degradation remains significantly lower than that of individual units,with the measured SACC decreasing by only 0.14％and CEER declining by approximately 1.2％.Additionally,the material cost of a single heat exchanger can be reduced by 8.4％.These findings offer the industry a strategic reference for achieving notable cost reductions through minimal performance trade-offs.

Abstract:This paper studies the energy consumption of a 300L chest freezer with a bottom-mounted evaporator in accordance with the test method specified in EN 62552-2020,and analyzes the impact of defrost power of aluminum tube heater and defrost cycle on the overall energy consumption and defrost incremental energy consumption of the freezer.The results show that under the same conditions,when the total power of the aluminum tube heater is the same,the configuration with a power per unit length of 25 W/m reduces the overall energy consumption by 0.68％～1.02％compared with the configuration of 23 W/m.Under identical configurations,with the shortest defrost cycle fixed at 12 hours,the longest defrost cycles of 48 hours reduce overall unit energy consumption by 2.61％～2.95％compared to a 24 hours cycle.Meanwhile,the longest defrost cycles of 72 hours and 96 hours increase energy consumption by 0.11％～0.72％and 0.02％～0.57％respectively compared to a 48-hour cycle.When selecting the longest defrost cycle,the 48hours option offers the best cost-effectiveness.

Abstract:Traditional heat pump air conditioners experience frequent frosting and defrosting in low-temperature environments,leading to a significant decline in continuous heating performance,which restricts the promotion and application of heat pump air conditioners.In response to these issues,conducts theoretical analysis and experimental verification on the impact of system parameters such as compressor frequency,electronic expansion valve opening,and exhaust temperature during low-temperature heating operation,as well as the changes in heat exchanger tube temperature on heating performance and frosting/defrosting conditions.The results show that improving low-temperature heating performance requires a comprehensive consideration of the effects of compressor operating frequency,electronic expansion valve opening,and heat exchanger tube temperature;it is possible to appropriately increase the evaporating pressure and temperature of the air conditioning system to weaken the impact of outdoor heat exchanger frosting and defrosting on low-temperature heating performance;during the operation phase before entering defrosting,it should be avoided to continuously reduce the opening of the electronic expansion valve,which would decrease the circulation flow of the air conditioning system and thus accelerate the rapid decline of the system's low-temperature heating performance.

Abstract:Aiming at the problems of significant differences in user operation habits and insufficient energy-saving awareness in heat pump heating systems,it proposes a Model Predictive Control(MPC)strategy for heat pumps based on a data-driven hybrid model.By analyzing the operational data of 210 users in northern China,user behaviors were categorized into three types:non-adjusting,less-adjusting,and frequent-adjusting,revealing that 60％of users exhibit operational inertia or a lack of knowledge.On this basis,a hybrid model combining a 4R3C building thermal resistance-capacitance model with a BP neural network for heat output prediction was constructed.Parameters were identified using a genetic algorithm,and automatic optimal adjustment of water temperature was achieved through MPC.Experimental results show that this strategy can achieve energy savings of 6.5％to 15.7％while maintaining indoor comfort,verifying its effectiveness and feasibility in practical applications.

Abstract:For a specific outdoor unit model experiencing abnormal noise at the 6th harmonic frequency during heating operation,subjective evaluation indicated failure.Through quasi-steady-state compressor frequency sweep testing,along with modal and modal strain energy analysis of the compressor piping system,it was determined that the 6th harmonic exceedance was caused by structural resonance of the liquid receiver.An optimized solution involving reinforcement of the liquid receiver welded bracket was proposed to enhance connection stiffness and natural frequency.Experimental testing demonstrated that the optimized solution achieved a 19 dB reduction in peak noise level at the 6th harmonic compared to the original design.The abnormal noise was eliminated,and subjective evaluation results were favorable.

Abstract:To address the noise issue caused by resonance excitation of the natural frequency in accumulator structures,investigates the influencing factors of natural frequency in accumulator structures.Based on single-degree-of-freedom system theoretical analysis,the natural frequency is primarily determined by the structural"stiffness"and"mass".A finite element numerical simulation model was established with less than 5％error between theoretical calculations and experimental measurements.Characteristic dimension sensitivity analysis reveals that bracket feature dimensions primarily affect the upper natural frequency:increasing bracket thickness,width and height enhances bracket stiffness and raises the upper natural frequency,with sensitivity ranking:bracket thickness＞bracket width＞bracket height.Bend and cylinder wall thickness dimensions mainly influence the lower natural frequency:increasing bend wall thickness,reducing bend length and thinning cylinder wall thickness improve bend stiffness and reduce cylinder mass,thereby increasing the lower natural frequency,with sensitivity ranking:bend wall thickness＞bend length＞cylinder wall thickness.In a practical case study with largely finalized product structure,thickening the bend wall thickness—a minimal structural modification—effectively adjusted the natural frequency and resolved the accumulator noise issue.

Abstract:Modern micro wave ovens,in addition to basic micro wave heating,integrate multiple cooking functions such as steaming,boiling,baking and air frying,aiming to provide users with a more convenient and diverse cooking experience.During the operation of a microwave system,the magnetron generates a large amount of heat by converting electrical energy into magnetic energy.In addition,the internal electronic components(such as amplifiers)consume electrical energy and convert it into thermal energy when working.Excessively high temperatures may lead to a decline in equipment performance or even damage.Therefore,effective heat dissipation is crucial for ensuring the normal operation of microwave equipment and has become one of the important demands in the industry.To this end,by leveraging artificial intelligence solutions,an innovative intelligent control dual-power enhanced heat dissipation technology was designed.The heat dissipation system was optimized from a single air duct to a dual air duct,and a digital model of microwave working condition temperature rise was established.CAE simulation calculations were carried out to continuously verify and optimize,achieving a dynamic balance among the energy input to the microwave oven,the food absorption capacity,and the heat dissipated from the residual heat,effectively improving the working condition temperature rise.The temperature has been reduced from the original 78.49 ℃ to 68.50 ℃,improving the quality of cooked food and increasing the cooking efficiency by 21.9％.This ensures that the temperature during the combined cooking operation of the microwave oven is controlled within a reasonable range,thereby extending its service life and ensuring usage safety.

Abstract:Although there are already products on the market using R290,there is room to improve its annual performance factor(APF).Optimizes the heat exchange system of a 1.5-horsepower R32 household wall mounted air conditioner using R290 refrigerant as substitute to improve its energy efficiency through simulation and experimentation.Firstly,the optimal refrigerant filling amount was tested.The results showed that the system had the best performance when the filling amount was 300 g,with APF of the system reaching 4.812,and the filling amount met the maximum filling amount requirements of the specifications.Secondly,through testing,it was found that when replacing R32 with R290 refrigerant,there were two aspects that need special attention due to different characteristics of the refrigerants:(1)R290 refrigerant had higher requirements for the distribution effect of the distributor,and the problem of uneven distribution in the heat exchanger could be greatly improved by optimizing the distributors of internal and external unit;(2)R290 refrigerant was sensitive to pressure drop.By eliminating the subcooling section and replacing the connecting pipe,the system pressure drop could be effectively reduced.The APF of the prototype increased by 5.84％after optimization,reaching first level of the energy efficiency of national standard.

Abstract:To address the issue of frequency oscillation in variable-speed air conditioners caused by elevated discharge temperatures under high ambient and high compression ratio conditions,a compressor frequency control framework is developed.The framework introduces a dynamic discharge temperature threshold and target frequency mapping based on risk levels,integrates rate limiting and anti-windup compensation in the speed regulation loop,and establishes a coordinated control and parameter tuning procedure that balances discharge temperature regulation with actuator rate and amplitude constraints.Experimental results show that,compared with conventional fixed-threshold logic,the proposed method reduces the frequency oscillation amplitude from±10 Hz to±2 Hz～±4 Hz,significantly shortens protection activation and recovery times,and mitigates fluctuations in airflow and room temperature while improving overall energy efficiency.Without any hardware modification,the proposed framework effectively enhances system stability and operational efficiency.

Abstract:Investigating the temperature distribution patterns and electrothermal conduction mechanisms of magnetic components during operation holds significant theoretical and practical value for optimizing device design and enhancing system reliability.Focus on the temperature rise of magnetic components in household variable-frequency air conditioning electric control systems.Based on the electrical characteristics of magnetic elements and their loss mechanisms,establish a multi-physics coupled simulation model integrating electrical,magnetic,loss,and thermal fields to systematically analyze the electrothermal coupling process from electrical parameters to temperature distribution.Furthermore,numerical simulations and analysis are conducted to examine the temperature rise characteristics and distribution patterns of PFC inductors.The results demonstrate that coupling the electrothermal process through component loss calculations can effectively predict the thermal behavior of magnetic devices,providing a reliable theoretical foundation and technical support for design optimization and addressing excessive temperature rise issues.This approach establishes a technical basis for board-level electrothermal co-design in thermal management,thereby reducing development costs.

Abstract:At present,the transparent interior parts of refrigerators are mostly injection-molded with GPPS,and the cracking of these parts during transportation and use has become a major economic loss in the refrigerator industry.Focused on exploring the possibility of using PET material,which had better anti-cracking ability,to replace GPPS in the production of transparent interior parts for refrigerators.By comparing the key properties of PET and GPPS,the superior anti-cracking performance of PET was highlighted.Furthermore,the SWOT analysis matrix was used to demonstrate the potential opportunities and challenges of applying PET material in refrigerator transparent interior parts.Practical examples were provided to illustrate the issues and precautions to be aware of when designing and producing PET transparent interior parts for refrigerators.Finally,based on the market feedback of a certain refrigerator model that had switched to PET material,the quality improvement and economic benefits brought by using PET material were summarized.

Abstract:People's demands for a higher quality of life are increasing in the post-epidemic age,and they are becoming increasingly conscious of the comfort of indoor air.The health and comfort features of household air conditioners have gained significant attention in recent times,making them popular choices for air conditioning.Conventional air conditioners frequently have a mechanical air supply,cool directly with cold air rushing in,a heating head is hot while the feet are cold,and poor human comfort.The double-walled multi-spout air deflector is a new type of air guide plate that this paper proposes.It is designed using the multi-jet nozzle jet principle and diffuser principle as its foundation.To optimize the splash type interference soft wind deflector,different air guide plate porosity,soft air ring porosity,air outlet shape,and soft air ring spacing were used in the organization of the airflow numerical simulation using Fluent software.Through a comparative analysis of wind speed distribution,end face air volume,turbulence intensity,and other parameters,the best air comfort soft wind ring guide plate program was evaluated.Finally,the air comfort test was conducted to confirm the soft wind effect of the soft wind ring guide plate.According to the findings,the splash type interference soft wind deflector can effectively reduce wind speed in the area of human activity,realizing the effect of soft wind,and enhancing user experience.It can also lessen the sense of blowing while maintaining the air conditioner's cold volume and wind volume without affecting the air conditioner's normal cooling and heating of the air supply range.

Abstract:With the improvement of living standards,more and more users have purchased steam ovens that bring a lot of convenience and culinary pleasure.At the same time,while people are enjoying delicious food,steam oven also bring about some pain points such as the grilled meat becoming tough,burnt and the oil stains being hard to clean.To this end,by applying the optimization theory and building a digital technology model,the method of finding the optimal solution under given conditions is explored.The intelligent optimization control technology for steam ovens is innovated.Through precise algorithms,multiple factors such as temperature,humidity,and heating time during the cooking process are intelligently controlled for cooking verification and iterative optimization.Realize the iterative upgrade of cooking methods such as"dual control of temperature and humidity for fresh steaming,self-controlled maturity,and high-temperature self-cleaning of oil stains",achieving the best cooking effect of deliciousness and texture.Effectively address the pain points of meat texture being tough and fat being difficult to clean for users,and enhance the level of user experience reputation.

Abstract:An accurate measurement method based on thin wire thermocouple is proposed to solve the problem of lack of measurement method for freezing point temperature of test package in performance test of refrigeration appliances.By comparing the measurement results of platinum resistance and thermocouple,it is found that platinum resistance is easily disturbed by the environment because of its size,and the thin-wire thermocouple can significantly reduce the data deviation when it is arranged in the geometric center of the test package,which is more suitable for measuring the freezing point temperature.The method of determining the stable condition in the freezing process is clarified,and it is suggested that the stable condition of temperature fluctuation limit per unit time should be used to screen representative data,and the freezing point temperature should be obtained by calculating the average value.In addition,it is proposed to correct the measurement results based on the freezing point of pure water to eliminate the influence of equipment and environmental factors and ensure the comparability of cross-laboratory data.Experiments show that this method can effectively improve the accuracy of freezing point temperature of test packages,and provide technical support for standardization and reliability of refrigeration appliance testing.

Abstract:In VRF air conditioning system,efficient heat dissipation directly determines the overall performance and compactness of the machine.Compared with traditional finned heat exchangers,refrigerant radiators are increasingly becoming the preferred choice for electronic control modules,especially IPM cooling solutions,due to their excellent heat dissipation efficiency,stable heat dissipation performance,and low sensitivity to environmental temperature changes.To accurately quantify its performance,conducted an in-depth analysis of a refrigerant radiator applied to practical products through a combination of theoretical modeling and experimental testing,measured the overall thermal resistance of the refrigerant during cooling,revealed the distribution of its internal thermal resistance through measurement.Based on this data,propose three optimization schemes,which provide reference technical paths for the design of next-generation high-power density and high reliability multi split products.

Abstract:Indoor formaldehyde pollution poses a serious threat to health,urgently requiring efficient control.Air conditioning systems integrated with formaldehyde removal functions,leveraging their advantages of wide coverage and high frequency of use,serve as an ideal platform for the synergistic regulation of temperature,humidity,and air purification.This paper systematically reviews the sources and long-term release characteristics of indoor formaldehyde.The principles,effectiveness,and limitations of mainstream formaldehyde removal technologies integrated into air conditioners were critically examined.Moreover,the constraints on actual performance imposed by dynamic environmental parameters,complex pollution sources,system compatibility,and user requirements were analyzed.Finally,the key direction of aldehyde removal technology upgrading is prospected,which provides guidance for the research and development of the next generation of efficient and intelligent purification solutions.

Abstract:Under the"dual carbon"goals,systematically examines the current status,challenges,and countermeasures of low-carbon transformation in China's home appliance industry.Industry data from 2024 shows that the main business revenue of home appliances reached 1.95 trillion yuan,with production rebounding but carbon emissions remaining a prominent issue.Corporate carbon emissions exhibit a divergent trend:for instance,Haier Smart Home reduced its emissions by 23.86％in 2023,while TCL and Midea saw increases exceeding 50％.The industry faces challenges such as reliance on energy structure,insufficient technological innovation,and weak supply chain collaboration.Both domestic and international experiences indicate the need for policy guidance and technological innovation to drive transformation.Domestic research primarily focuses on technological innovation,environmental regulations,and industrial chain collaboration.Recommendations include:strengthening R&D in energy-saving and emission-reduction technologies,optimizing the energy structure,and striving to achieve zero growth in manufacturing sector carbon emissions by 2030;improving the carbon trading market by expanding coverage and enhancing carbon price effectiveness;enhancing talent cultivation,promoting technological transformation,and industrial upgrading;expanding green foreign trade to elevate value chain status.

Abstract:With the rapid development and deep integration of Internet of Things(IoT),artificial intelligence(AI),big data,and cloud computing technologies,smart homes are transitioning from single-product intelligence to a new stage of whole-scene intelligence.As the core hub of the smart kitchen and a key node in family health management,the value of smart refrigerators has far surpassed traditional refrigeration and preservation functions.Their core competitiveness is increasingly focused on the intelligence level of food management capabilities.However,the isolated development of food recognition technology alone does not support the vision of smart refrigerators as the"family health management hub."By systematically exploring the evolution of food management functions in smart refrigerators,this study analyzes the core development trends from technical,functional,and ecological dimensions,aiming to provide new directions and insights for the overall development of the smart refrigerator industry.