Abstract:At present,air-cooled refrigerators have a relatively large market share,but their refrigeration evaporators rely on electric heating for defrosting,which has problems such as high power consumption,high freezing temperature rise,and poor preservation.Therefore,new heat pump defrosting systems for single system and dual system frost free refrigerators were proposed separately.The heat pump converts less electricity into increased defrosting heat.Through system simulation theory analysis and whole machine experimental research,it was finally verified through experiments that the heat pump defrosting scheme has significant advantages over electric heating defrosting.Among them,the energy consumption of refrigerator heat pump defrosting can be improved by more than 80％,and the temperature rise in the freezing room can be reduced by more than 50％.The heat pump defrosting solution provides a new technological route for the energy efficiency upgrade of future refrigerators and the research and development of ultra efficient refrigerators.

Abstract:After 48 hours of continuous operation in a high-temperature and high-humidity environment,the air conditioner indoor unit generates a significant amount of condensation water inside the human sensing module,posing risks such as circuit board short circuits and even fire hazards.To address this issue,a moisture condition analysis was conducted for the indoor unit,and a moisture-proof method for the human sensing module was proposed.Firstly,fluid simulation analysis of the air duct structure was performed to determine the causes of condensation water and the locations prone to its formation.Subsequently,a moisture-proof method for the human sensing module was proposed,involving the optimization of the lens structure,the application of UV adhesive to improve sealing,and the addition of insulation cotton to reduce thermal conduction.Finally,validation was carried out through moisture condition testing.Results show that the proposed moisture-proof method effectively resolves the issue of condensation water formation inside the human sensing module.

Abstract:The performance of the suction and discharge processes in a refrigerator reciprocating compressor is largely determined by the movement pattern of the valve plate.Traditional analytical methods generally assume uniform flow at the suction port.However,during the suction process,the geometry of the suction valve plate results in varying instantaneous flow patterns at the valve port.Different flow patterns lead to significant differences in suction losses,thereby affecting compressor performance.By applying the fluid-structure interaction(FSI)model validated through experimental studies,the influence of the suction valve assembly structure on valve plate movement and fluid performance during the compressor's suction process was investigated.The results demonstrate that optimizing the design of the suction port and valve plate shape can effectively increase suction volume,reduce flow losses,and minimize backflow caused by delayed closure.Performance test results show significant improvements compared to the original design.The two optimized suction structure schemes achieve high-frequency cooling capacity increases of 9.9％and 8.5％,respectively,and low-frequency COP improvements of 2.2％and 3.1％over the conventional solution.

Abstract:In terms of theory,the contact between the microchannel flat tube and the water tank is surface contact,the traditional copper tube outer-coil contact area with the out wall of the tank is line contact,it is obvious that the contact area of the microchannel is larger,which is beneficial to the heat exchange between the water and the water tank,and also enhances the energy efficiency.At present,in the market of heat pump water heaters,it is concluded that most manufacturers are using microchannel enamel outer-coil water tank,and most are high energy-efficient products,only a few manufacturers are using copper outer-coil water tank.By testing and comparing the copper tube outer-coil water tank and the microchannel enamel outer-coil water tank,it is concluded that the microchannel enamel outer-coil water tank is better than the copper tube outer-coil water tank in terms of energy efficiency and heating capacity,and reduces a certain amount of refrigerant charge.It helps to improve the heating capacity and the energy efficiency,so that finally improve the production of hot water effectively.

Abstract:With the rapid popularization and promotion of smart homes and smart cars,most users have felt the convenient experience brought by smart life and travel,and they often encounter the problem that smart homes and smart car cockpits cannot be interconnected,resulting in poor user experience.Aiming at the current problems of data islands,interaction fragmentation,and weak task collaboration"between smart home and smart cockpit systems,proposes a cross-domain agent interaction technology based on MCP protocol and large model.This technology takes the automotive smart cockpit(vehicle agent)and the smart home smart home brain screen(home agent)as the core interaction nodes,relies on the MCP protocol to realize cross-system device control and state synchronization,and combines the context understanding,task splitting and continuation capabilities of the large model to build a cross-domain interaction system of scene linkage-task collaboration-service customization".Judging from the laboratory data,the cross-domain instruction response delay of this technology is ≤ 500 ms,the task continuation success rate reaches 94.3％,and the user scenario demand satisfaction rate has increased to 96.5％,which is 3.8 times higher than the interaction between the traditional smart home and the smart cockpit two independent systems,significantly breaking the interaction barriers between smart homes and smart cockpits,and realizing the ultimate experience of users' smart life+smart travel intelligent interaction and non-inductive collaboration.

Abstract:Refrigerator odor is a key issue affecting user experience and food preservation.To address the inadequacy of traditional methods in real-world scenarios,aimed to empirically compare the actual efficacy,user experience,and safety of three deodorization technologies:compound bio-enzymes,activated carbon,and ozone generators.Seventy-five households were recruited and randomly assigned to three groups for a four-week field test.Data were collected via odor intensity scales,user satisfaction,and safety questionnaires.Results showed that the compound bio-enzyme group achieved an 81％reduction in odor score,the ozone generator group 72％,both significantly outperforming the activated carbon group(39％).The bio-enzyme group led comprehensively in satisfaction(4.5/5.0),perceived safety(4.8/5.0),and convenience(4.9/5.0).While the ozone generator was effective,it received lower ratings for safety and convenience(2.9/5.0).It is concluded that compound bio-enzymes offer a safe,efficient,and imperceptible solution for daily use,whereas ozone generators are more suitable for rapid emergency treatment,and activated carbon technology shows limited effectiveness.Provides direct user-experience-based evidence and selection criteria for optimizing deodorization functions in the home appliance industry.

Abstract:The reliability of electric heating was studied in accordance with the requirements of the UL 60335-2-40-2022"Safety of Household and Similar Appliances Special Requirements for Heat Pumps,Air Conditioners and Dehumidifiers"standard for rooftop electromechanical heating exported to North America.Based on the characteristics of the roof electromechanical heating structure,the theoretical analysis model of electric heating heat transfer is established,the coupling relationship between the surface temperature and wind speed of the electric heating wire is obtained,and the wind field distribution is determined by simulation,and the test results verify the reliability of the theoretical model and simulation,which provides theoretical basis and engineering guidance for the installation design of roof electromechanical heating.

Abstract:In view of the increasing demand for real-time monitoring of the closed state of the smart refrigerator door,and the traditional door magnetic or mechanical switch has some problems,such as complex assembly,easy failure of low-temperature condensation and high cost,etc.,a door ajar detection method based on refrigerator operation big data is proposed.This method does not need to add new hardware,but uses a big data platform to build an off-line abnormal database with compressor status bit,evaporator temperature,refrigeration temperature,freezing room temperature,defrosting cycle and other related multi-source operation data as inputs,which provides a low-cost and landing detection solution for intelligent operation and maintenance of refrigerators.

Abstract:With the increasing demand for energy conservation,environmental protection,comfort and health in society,the fixed operation mode of traditional air conditioning is no longer able to meet the personalized needs of users.Infrared human sensing technology provides an effective solution for the intelligent and energy-saving control of air conditioning by detecting the presence,location,movement,and quantity of indoor human bodies.Firstly,elaborates on the basic principles of infrared human sensing technology,and then studies the relationship between the installation position and detection range of infrared human sensing devices on air conditioners to determine the installation angle of infrared human sensing devices.Secondly,in order to verify the detection range and sensitivity of the human sensing device,an operation plan and detection plan for the infrared human sensing device were designed.Finally,through experimental verification,when the human sensing device is designed at a 40° angle between the middle position and the horizontal direction of the air conditioner,it can achieve effective range detection of 0.5 m to 5 m in front and back,and-50° to 50° left and right for people in different postures such as standing,sitting,and lying,ensuring the detection range and sensitivity of the air conditioner's infrared human sensing.

Abstract:As the construction industry undergoes digital transformation and smart home environments continue to evolve,the demand for automated layout solutions for home appliances and furniture has grown significantly.Introduces an interior layout optimization method that integrates prior knowledge with Particle Swarm Optimization(PSO)to enable efficient and intelligent spatial arrangement.Initially,major furniture and appliance objects are grouped based on spatial semantic rules,allowing a rule-driven system to generate a reasonable initial placement.A multi-objective cost function is then formulated,incorporating both object-to-object relationships and spatial constraints derived from floor plan structures.PSO is applied to iteratively optimize the layout across the entire space.By leveraging structural layout information and predefined item groupings,the method enhances both the accuracy of the initial arrangement and the convergence speed of the optimization process.The approach balances individual object placement with overall spatial harmony.Experimental results show that the generated layouts are both practical and esthetically comparable to manually designed configurations.This work exemplifies the application of artificial intelligence algorithms in the optimization of furniture and appliance layouts,and holds strong potential for deployment in smart home design systems.

Abstract:With the increasing popularity of wool fabrics,the problem of their complicated washing and care has gradually emerged.The wide application of household tumble dryers has provided a convenient solution for drying wool fabrics.However,consumers often find it difficult to accurately distinguish which dryers are truly suitable for wool fabrics and which ones may pose a risk of damaging the clothes.At present,the domestic standard system for the drying performance of wool fabrics is still not perfect.Only a few group standards are available for reference,and their testing methods mostly draw on the norms of the International Wool Secretariat(IWS).Therefore,select the testing method of the IWS for interpretation,aiming to provide clear R&D guidance for relevant manufacturing enterprises through in-depth analysis of this standard test method,assist in the development of wool-friendly dryers that better meet market demands,thereby enhancing user experience and promoting the overall development of the industry.

Abstract:To solve the problems of reduced energy efficiency and"defrosting without frost"caused by the traditional timed defrosting strategy in air conditioners,a synergistic control strategy based on precise frost point judgment and active frost suppression with variable frequency is proposed.This strategy establishes a mapping of ambient temperature-humidity to frosting status,using the frost point temperature as the core criterion to accurately determine the timing for defrosting.Concurrently,it actively raises the evaporation temperature by dynamically adjusting the compressor frequency during different stages of frost development to suppress frost nucleation and retard frost layer growth.Experimental results show that this synergistic strategy can effectively extend the continuous heating period by 36％under the-7℃/RH70％condition,and significantly improve the comprehensive winter energy efficiency by 6.7％under the-12℃/RH65％condition.This research provides an effective technical solution for enhancing the heating comfort and energy-saving performance of heat pump air conditioners in cold and humid environments.

Abstract:An experimental research was conducted on the changes in energy efficiency grades of typical commercial refrigeration appliances under the GB 26920-2024 standard,and the maximum allowable values of energy consumption and the variation range of energy efficiency grades were analyzed.The results show that,the GB 26920-2024 standard significantly raises the energy-saving requirements for vertical display freezer,horizontal display freezer and stainless steel refrigerators.Compared with the current standard GB 26920.2-2015,the maximum allowable values of energy consumption of vertical display freezer and stainless steel refrigerators decreased by 24％to 35％under the GB 26920-2024 standard,and the energy efficiency grades dropped by 2 to 3 grades.The maximum allowable values of energy consumption of horizontal display freezer decreased by 16％,and the energy efficiency grade dropped by 1 to 2 grades.The requirements for commercial ice makers under the GB 26920-2024 standard are relatively moderate.Ice makers with R290 refrigerant system can reach the energy efficiency grade 1 and with R404A refrigerant system can reach the energy efficiency grades 2 to 3.

Abstract:After the Kigali Amendment was passed in 2016,185 countries joined and officially came into effect.The bill requires Article 5 countries to freeze the baseline of HFCs from 2023 to 2025 and begin reducing HFCs from 2026.As R32 dominates the household air conditioning market,low GWP R290 and HFOs are the main choices for reducing HFC emissions.However,due to the harm of PFAS to the environment and human health,a global ban on PFAS is being pushed forward,including some HFOs refrigerants such as R1234yf/ze,R1233zd,etc.Therefore,to meet the dual demands of GWP and PFAS,R290 is currently one of the main choices for refrigerant substitution.R290 has natural advantages and disadvantages in the field of household air conditioning.Based on the physical differences between R290 and R32,proposes the main impact of R290 replacing R32 on the system and compressor,and designs a new R290 compressor for 1.5 HP AC under this guidance.

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.