Abstract:In order to improve the energy efficiency of the rotary two-stage compressor,the two-stage compression chamber uses structural mesh to divide the compression chamber,calls FORTRAN in CFX to control the radial movement of the nodes of the compression chamber,and simulates the primary and two-stage compression processes.Subsequently,experiments verify that the simulation model is accurate,providing theoretical support for energy efficiency improvement.Based on the validated model,three types of intermediate chambers are proposed,and hybrid configurations,the intermediate chamber is arranged inside the compressor,outside the compressor,and the hybrid structure of the two.The result analysis shows that the structure of the intermediate chamber determines the first stage exhaust pressure,second stage suction pressure,and pressure pulsation.The intermediate chamber is arranged inside the compressor,with low first stage exhaust pressure and large pressure pulsation,low power consumption,and optimal energy efficiency,providing support for subsequent energy efficiency improvement.

Abstract:To study the possibility of the microchannel heat exchanger(MHX)replacing the fin-tube heat exchanger(FHX)in heat pump air conditioning systems,a simulation analysis of the composite fins used in the MHX is conducted,and the effects of the louver angle and wave height on the flow and heat transfer was studied.The results show that when the air velocity is below 2.3 m·s-1,a louver angle of 28° is optimal.A wave height of 1.0 mm is superior to 0.8 mm and 0.6 mm.Subsequently,the system defrosting performance of the outdoor unit using vertical-fined MHX and FHX is tested.The defrosting process is divided into the start-up,melting,and drainage stage.The total defrosting time of the MHX is 276 s,which is 45 s(19.5%)longer than that of the FHX.The duration of melting stage is 1.58 times that of the FHX,but the duration of the drainage stage does not increase significantly.

Abstract:Addresses the technical bottlenecks in the traditional hot sleeve assembly process for air conditioner compressor rotors,such as uneven heating temperatures,excessive energy consumption,and the risk of workpiece thermal deformation.It innovatively proposes a cold sleeve assembly process.Through a combination of theoretical analysis and experimental verification,the research found that under existing dimensional tolerances,a press-fit force of 17.1 kN would cause the radial deformation of the crankshaft secondary shaft to exceed the design allowable limit(radial deformation≤2 μm).After optimizing process parameters and employing a lubricant surface treatment technology,the mean press-fit force was successfully reduced by 3.41 kN while maintaining the force stability to meet the requirement of≥3 MPa.Comparative test data demonstrated that implementing the cold sleeve process increased the compressor COP value by 0.4%and significantly improved the process capability index(Cpk)for assembly height dimensions from 1.09 to 2.92.The results confirm that the cold sleeve assembly process offers significant technical advantages in assembly accuracy control,energy savings,and product reliability enhancement,providing an innovative solution for the efficient and precision manufacturing of compressors.

Abstract:To address the issue of uneven refrigerator door heights,a novel adjustable hinge model has been developed,enabling height adjustment to maintain door alignment.The study focuses on the overall design concept of the adjustable hinge,control of key risk points,and solutions to problems encountered during experiments.Simulation analysis and experiments were conducted from both the whole machine and individual component perspectives,verifying the reliability and practicality of the adjustable hinge,which surpasses conventional hinges.Regarding the risk of thread loosening in the adjustable hinge,theoretical calculations and experiments demonstrated that adding a fastening set screw eliminates the risk of loosening under actual working conditions.In response to issues such as salt spray corrosion and motion interference observed during experiments,the structure of the adjustment shaft was optimized,and materials were carefully selected.The optimal thread tolerance and grade were chosen based on practical operation convenience and reliability.Through the presented analysis and research,it has been demonstrated that the adjustable hinge not only retains all functionalities of conventional hinges,but also incorporates an adjustment capability,representing a technologically upgraded hinge model.This innovation provides a novel solution for effectively addressing refrigerator door misalignment issues,offering both theoretical guidance and practical methodology for appliance manufacturing optimization.

Abstract:With the acceleration of urbanization,high-rise housing has become the mainstream form of living,and the diffusion of kitchen soot particles poses a serious threat to indoor air quality and residents' health.The physicochemical properties,diffusion mechanism and health risk assessment methods of cooking fume particles in high-rise residential kitchens are systematically reviewed,and the pollutant propagation law in the special environment of high-rise buildings is analyzed,and the optimization path and future trend of ventilation control technology are prospected.The results show that the thermal plume effect of soot particles(pm2 5/ufps)is dominant,and the chimney effect aggravates the cross household transmission in high-rise residential buildings;The design of air supplement system and the optimization of smoke exhaust duct structure are the key to control pollutant concentration;In the future,it is necessary to integrate intelligent monitoring,green materials and interdisciplinary research to build a healthy and safe kitchen environment.

Abstract:Addressing the discrepancies between the requirements for components in household appliance whole-product standards and the specific standards for components themselves,aims to systematically analyze these differences and provide clear compliance guidance for home appliance manufacturers.Using a comparative analysis approach,the research first outlines the requirements for key components in the latest whole-product standards,such as GB/T 4706.1-2024,and highlights the concerns of relevant stakeholders in the industry chain.It also summarizes the updates and revisions of current standards for major components.Subsequently,an in-depth comparative analysis was conducted to examine the alignment between whole-product standards and component standards in terms of specific requirements,categorizing them into two types:"covered by certification standards"and"not covered by certification standards."Finds that for most component products,their standards can adequately cover the requirements of whole-product standards.However,for certain components such as switches and relays,there are unresolved differences in key indicators like durability testing and test conditions,necessitating supplementary tests.Provides a theoretical foundation and practical guidance for enhancing standardization and compliance within the home appliance industry chain.

Abstract:Recently,the World Health Organization has proposed for the first time in its vaccine refrigerator series standards the requirement for an Vaccine Cold Chain Equipment Monitoring System(EMS),with the aim of achieving standardization and interoperability of vaccine cold chain equipment data collection to support national EPI programs.The EMS monitoring system requirements proposed by WHO indicate that WHO's control of the vaccine cold chain will adopt intelligent means towards data electronification,remote monitoring,and system integration.The WHO standards are not only applied in WHO projects,but also highly recognized in some countries and regions in Africa and Southeast Asia.They are one of the standards that are widely used in the export of vaccine refrigerators in China.This standard upgrade involves the upgrading of product hardware and software,which has a significant impact on enterprises.In order to facilitate relevant personnel to quickly familiarize themselves with and understand the standards,the WHO vaccine refrigerator EMS requirements were analyzed through literature analysis and standard interpretation methods.The WHO vaccine cold chain related standards and requirements required to achieve EMS requirements were sorted and summarized using comparative analysis methods.Examples were given to illustrate their verification methods,experimental equipment requirements,and issues to be noted in the experiments,providing reference for vaccine refrigerator enterprises to complete product development and pass verification smoothly.We also hope to provide reference for China to achieve full chain supervision of vaccine cold chain and improve the vaccine cold chain standard system for long-term development through the research of WHO vaccine cold chain series standards.

Abstract:In order to further reduce the working noise of the range hood and improve the user experience,based on the response surface optimization technology,through the parametric modeling of the impeller,three key parameters are determined as the key optimization objects according to the previous test data.taking the range hood's working noise,anechoic chamber noise,maximum static pressure and stir-frying air volume as targets,multi-parameter and multi-objective test optimization is carried out.The analytical relationship between the parameters and the target is determined through 13 groups of test schemes,and the impeller parameters are given when the working noise,the noise of the anechoic chamber is the lowest,the maximum static pressure and the air volume of stir-frying are maximum.This method can find the global optimal solution of the problem in a given range.

Abstract:The study aims to address the complexity of program settings in current smart washing machines.Based on user experience,a simplified interaction model is constructed by analyzing questionnaire surveys and user behavior data to identify key factors affecting operational efficiency.Proposals include optimizing interface hierarchy,applying scenario-based recognition technology,and implementing multi-channel feedback mechanisms.Prototype testing verifies the optimization effects,showing a significant reduction in user operation time and a notable improvement in satisfaction.The research results provide theoretical support and practical guidance for human-computer interaction design in smart home appliances.

Abstract:An analysis of the reasons for speed vibration in the low-speed range of a single-cylinder compressor system in a variable-frequency air conditioning system,caused by the non-constant load during the compressor's operating cycle,is conducted.Based on the estimation of the motor rotor position,an effective method for automatically estimating the current load condition is proposed.According to the estimated load,automatic torque current feedforward compensation is performed.A simple load torque observer is designed using an output feedback method.This observer is a simplified design of the traditional second-order Luenberger observer,featuring fast convergence and small phase delay,making it easy to implement on embedded platforms.Since the observer itself belongs to the category of adaptive control,the use of the load torque observer can avoid the frequent parameter tuning caused by open-loop compensation.Simulation and experimental verification show that this method can significantly reduce speed fluctuations at low speeds of the compressor,validating its effectiveness.

Abstract:The top-outlet wind air conditioner outdoor unit electric control box as the research object,and conducts verification on its thermal and waterproof performance.During the repeated trial and error process of the original electric control structure,the paper analyzes and summarizes the disadvantages of the original electric control design in terms of heat dissipation and waterproofing.By conducting a retrospective analysis based on the overall electric control layout,a new electric control scheme is proposed,and the revised scheme is retested.The scheme has successfully solved the original thermal and waterproof problems of the top-outlet wind air conditioner,and the revised scheme has certain referencevalue for the subsequent design of top-outlet wind type products.

Abstract:The issue of increased noise in refrigerators caused by compressor vibration.Through sweep frequency testing and modal analysis,the vibration characteristics of the compressor-refrigerator coupled system were investigated.The results indicate that the vibration of the compressor in three directions varies with rotational speed,which is closely related to the modal properties of the vibration isolation system composed of the compressor and rubber pads.Vibration amplitude increases significantly when excitation frequencies approach the system's modal frequencies.In the integrated refrigerator environment,the modal frequencies of the vibration isolation system decrease to varying degrees due to the stiffness of the chassis,leading to a corresponding reduction in resonance speeds.The study demonstrates that effective noise control requires comprehensive consideration of the combined stiffness of the rubber pads and the chassis.Optimizing the parameters of the rubber pads can effectively suppress vibration and prevent excessive noise.These findings provide valuable guidance for the matching design of variable-frequency compressors and refrigerator systems.

Abstract:As a core influencing factor of air volume and noise for the indoor unit of duct air conditioners,the centrifugal fan is such that the former is a key indicator for measuring the performance of duct air conditioners,and the latter is directly related to the user experience.Taking a certain type of duct air conditioner as the research object,systematically explores the matching mechanism between the height of the centrifugal fan for duct air conditioners and the size of the air inlet under the condition of a fixed air inlet size through simulation and experimental verification of multiple groups of different fan height parameters,so as to extract the optimization rules for the fan height applicable to engineering design.The study shows that when simply aiming at maximizing the air volume,there is a theoretical optimal proportional relationship between the fan height and the air inlet size;however,when considering the noise control requirements simultaneously,it is necessary to suppress the generation of large-scale eddies in the casing through structural optimization,and at this time,the optimal matching parameters will be redefined based on the aerodynamic-noise coupling characteristics.

Abstract:To address the issue of indoor unit operating noise affecting user comfort,structural optimization was employed to reduce surging noise at the air outlet.Based on an extreme dimensional analysis of the fan and base housing assembly,it was discovered that the gap between the rear fan surface and the left end of the base housing was too large,which could easily lead to surging noise at the air outlet.The following structural optimization schemes were proposed:firstly,applying adhesive to the left air duct end surface of the base housing,and secondly,adding ribs to the right end surface of the base housing.Experimental results show that this scheme allows the rear fan surface to exceed the interior left end surface of the base housing air duct,creating a more uniform airflow channel on the left side and effectively reducing surging noise at the air outlet.

Abstract:With the growing user base of washing machines,personalized home appliances are also increasing.To enhance space utilization and aesthetic appeal,designers innovatively installed clothing care devices in countertop form,meaning the washing machine is mounted on kitchen counters or in confined spaces.This design not only saves space but also integrates seamlessly with the kitchen or balcony environment,improving overall aesthetics.However,due to the limited installation space for clothing care devices,the requirements for displacement caused by eccentricity are higher.When the device experiences significant displacement due to eccentricity,it may collide with surrounding objects or even fall off the countertop,increasing operational safety risks.Therefore,anti-fall technology is proposed for small washing machines.By analyzing the relationship between acceleration squared data and displacement,the risk of machine movement is predicted in advance,achieving a detection rate of over 94％.This method is reliable and enhances user experience.

Abstract:As a critical structural component in wall-mounted air conditioner indoor units,the base traditionally utilizes high-impact polystyrene(HIPS)for its exceptional material properties.With advancements in material technology,novel plastic alternatives have emerged.A modified HIPS material is investigated,synthesized by blending recycled polystyrene(PS)waste from air conditioner casings with virgin HIPS through crushing,sorting,and melt extrusion processes,achieving significant improvements in resource circularity.To validate its performance,specimen testing evaluated strength fluctuations,while high-low temperature cycling tests assessed extreme environmental adaptability.Results indicate that the modified HIPS exhibits comparable or superior comprehensive properties to conventional materials,with minimal strength variations confirming stable performance.Post-cycling tests revealed no deformation or cracking,meeting stringent operational requirements.This innovation provides the home appliance industry with a high-performance material solution that synergizes resource efficiency and technical viability.

Abstract:The microbial contamination of the refrigerator freezer has a great impact on the health of users.In order to investigate the situation of salmonella contamination in commercial fresh eggs and the influence of cold storage on the contamination in refrigerator freezer,salmonella detection was carried out in commercial fresh eggs.The contaminated fresh eggs were put into the refrigerator freezer and a controlled experiment was designed to detect salmonella in the refrigerator freezer.The results showed that salmonella was present in the batch of fresh eggs,and the contaminated fresh eggs caused salmonella contamination in the refrigerator freezer.The main biochemical characteristics of Salmonella were analyzed.The research results a direction for the development and design of refrigerator,and provided reference for the application of antibacterial materials,sterilizing modules and related tools in refrigerator.At the same time,it also provides guidance for the daily use and maintenance of refrigerator in families.

Abstract:In response to the concept of energy conservation,emission reduction,and recycling resources under the dual carbon goals,and to promote the shift of society and households towards more environmentally friendly and economical lifestyles,household refrigerator cryogenic and fast freezing technology has garnered widespread attention in recent years.This technology enables rapid freezing at lower temperatures,better preserves food nutrients,and reduces food loss and waste.Summarizes and organizes the principles,evaluation metrics,and implementation methods of cryogenic and fast freezing technology.It also analyzes the future development directions of this technology for household refrigerators,providing a reference for subsequent research.

Abstract:This study investigated the effects of temperature fluctuations on the quality deterioration of frozen salmon,aiming to provide theoretical guidance for the optimization of household refrigeration temperature control systems.Salmon samples were stored under constant temperature and fluctuating temperature conditions for 0-40 days,and changes in sensory quality,color parameters(L*,a*,b*),total volatile basic nitrogen(TVB-N),total viable counts(TVC),and texture properties were systematically evaluated.Results revealed that temperature fluctuations significantly accelerated quality degradation.After 40 days,sensory scores of the fluctuating group decreased to approximately 14,with markedly higher L*,a*,and b*values,indicating pronounced surface drying and browning.TVB-N and TVC increased to 1.3-fold and 1.32-fold those of the constant group,respectively,reflecting severe tissue damage and enhanced microbial activity.Hardness and chewiness decreased by 49.5％and 51.9％,significantly exceeding reductions observed in the constant group.Mechanistic analysis suggested that repeated freeze-thaw cycles induced by temperature fluctuations promoted ice crystal recrystallization,protein denaturation,and lipid oxidation,leading to structural destruction and flavor deterioration.These findings underscore the importance of stable low-temperature control in frozen storage and provide scientific support for advancements in refrigeration technologies and cold-chain management.

Abstract:As a core and critical process in air conditioner manufacturing,the refrigerant charging process is widely applied in the air conditioning industry.However,the absence of corresponding entity modeling in digital simulation has hindered the effective simulation of air conditioner production lines.Utilizes the Flexsim simulation platform to conduct secondary development for modeling process equipment,production lines,kinematic mechanisms,and task allocation logic,thereby realizing full production functionality.By integrating virtual reality(VR)display technology,a dedicated simulation platform for the charging process of air conditioner production lines was developed.An immersive virtual scene and digital twin model were established,with animations implemented through Flexsim coding.By embedding production processes into the simulation system,a novel simulation paradigm featuring"virtual experience combined with simulation calculation"was created to pre-evaluate whether production line capacity meets design standards.This research lays a foundation for accurately predicting production capacity and optimizing simulation results in practical production planning and line transformation,thus expanding the application scope of digital simulation technology in the air conditioning manufacturing sector.