Research on cooperative control strategy of temperature and humidity for domestic air conditionersAbstract:Accurate control of indoor temperature and humidity is essential to enhance human comfort.Aiming at the problem that it is difficult to maintain the temperature and humidity of household inverter air conditioners,proposes a cooperative control strategy for temperature and humidity.On the basis of the original indoor temperature PID control compressor frequency,superimpose the PI control increment of indoor humidity and increase the weight of dehumidification;the speed of the internal fan adopts incremental PID control and adaptively adjusts the control coefficients according to the indoor temperature difference to realize the stepless adjustment of speed to control the indoor temperature and humidity.By building the air conditioning sensible latent heat neural network model and room load model simulation verification,and experimental testing on the whole machine.The results show that,compared with the traditional temperature control only strategy,this cooperative control method can effectively suppress humidity rebound while maintaining the set temperature accuracy,stably control the indoor humidity in the comfort zone(40%~60%),and significantly improve the comfort regulation effect of the air conditioner.
Experimental study on the performance of air conditioners with 5 mm copper tube condensers operating in a wide temperature rangeAbstract:Through comparative experimental research on the performance of three flow path schemes of 5 mm copper tube double-row condensers,namely five-in-five-out,six-in-six-out,and eight-in-eight-out,in the air conditioner as a whole,the results show that the six-in-six-out flow path scheme of the 5 mm copper tube double-row condenser has the best performance in terms of capacity and energy efficiency when operating in a wide temperature range of outdoor ambient temperature from 35 ℃ to 60 ℃.The high pressure of the entire system is the lowest,the difference between high and low pressure is the smallest,and the operation reliability of the entire system is the best.The variance of the outlet temperature of each flow path of the condenser under different working conditions is the smallest,and the flow is the most uniform.Therefore,this scheme is the best flow path among the three flow path schemes.Through comparative experiments and tests with the prototype solution,it was found that the 5 mm copper tube double-row condenser solution can completely replace the 7 mm copper tube double-row condenser solution of the prototype.At the same time,this solution can be extended to multiple models for product development and use,which can reduce the overall machine cost by about 6%and decrease the refrigerant usage of the entire machine by up to 26%.While ensuring product quality,It can also achieve cost reduction and carbon emission reduction,contributing to the country's dual carbon strategic goals.
Simulation optimization and experimental research on parameters of air conditioning fan shroud bladesAbstract:With the continuous improvement of energy efficiency standards for household air conditioners,the traditional fan cover has been difficult to meet the energy-saving requirements.To study the parameters of the circular fan cover blades used in the outdoor units of 10-horsepower high-volume air conditioners,fluid simulation and experimental verification were conducted on the three-dimensional modeling of the fan cover.The influence of the radial spacing and twist angle of the fan cover ribs on the ventilation volume of the fan cover was analyzed.The results show that the model optimization method based on CFX three-dimensional numerical simulation can effectively optimize the structural parameters of the fan cover.After optimization,the ventilation volume of the fan cover increased by 5.2%at the same fan speed,which is of great significance for reducing the flow loss in the air conditioner duct and improving the energy efficiency of the air conditioner.
Research on cooking of stove based on weighing sensorAbstract:Addresses the limitations of smart gas stoves that rely on temperature sensor to identify boiling states,as well as the uncontrollable cooking outcomes caused by gas pressure fluctuations during smart recipe applications.An intelligent control solution based on weighing sensor is proposed.By monitoring cookware mass changes in real-time,boiling states are precisely identified.A regression model correlating evaporation rate with burner power and gas pressure is established.For soup-boiling/braising scenarios,evaporation patterns are investigated separately.Dynamic adjustment of burner power based on evaporation rates achieves precise control over the final volume of broth in cooked dishes.Utilizing weighing sensor signal values to achieve intelligent boiling recognition and dynamic burner power adjustment for gas stoves,enabling smart and precise cooking while enhancing user experience.
Analysis and research on the improvement of temperature rise in high-temperature cleaning performance of ovens based on digitalizationAbstract:After long-term grilling and cooking in the oven,the inner walls of the baking cavity often accumulate and settle a lot of grease and dirt,especially in the corners which are difficult to clean,becoming a pain point in the industry.Through the innovative design of high-temperature self-cleaning technology for the oven,the intelligent control program can rapidly heat the oven to an extremely high temperature of over 450℃ within 30 minutes,and then take about 90 minutes to incinerate or thematically crack the food residues,grease stains and other impurities inside.After cooling to room temperature,it only needs a simple wipe to shine like new and complete the cleaning.In view of the large amount of residual heat generated during the high-temperature cleaning process,an efficient thermal management system is needed to support temperature control under different modes,maintaining a dynamic balance between heat generation and heat dissipation,and avoiding excessive temperature rise under working conditions that could lead to the failure of control electronic components.This has become an urgent key technical problem to be solved.Through the analysis of the mechanism of the high-temperature self-cleaning function of the oven,a digital model of the temperature rise under the high-temperature self-cleaning condition of the oven was built.The key factors affecting the temperature rise and the technical parameters of the main components were carefully selected and optimized.Combined with CAE simulation analysis and experimental verification,the temperature rise in the space of the high-temperature self-cleaning box of the oven was reduced from 84.61 ℃ to 68.58 ℃.Ensure the safety and reliability of the electronic components of the control system and the entire machine,and effectively enhance the cleaning effect.
Study on aerodynamic noise characteristics of centrifugal fan based on non-uniform NURBS surface voluteAbstract:To reduce aerodynamic noise during the operation of centrifugal fans and improve the flow adaptability and acoustic performance of the volute structure,proposes a three-dimensional curved surface volute structure based on non-uniform NURBS parametric modeling.Using a traditional volute as a reference,CFD and FW-H acoustic analogy methods are employed to conduct integrated numerical simulations of the flow field and acoustic field.The results show that the curved volute structure,by creating a"high in the middle,low on both sides"tangential flow channel,significantly improves the flow path from the impeller outlet to the volute tongue region,making the main flow more stable,reducing flow separation,and decreasing the peak turbulent kinetic energy by over 30%.Based on this,the pressure distribution on the volute wall becomes more uniform,the amplitude of unsteady fluctuations decreases,and the sound source intensity is significantly reduced.Spectral analysis shows that the sound pressure amplitude in the main frequency band below 1000 Hz decreases by approximately 4.2 dB(A),with an average reduction in total sound pressure of 3.6 dB(A),demonstrating excellent broadband noise reduction capabilities.The research results validate the comprehensive advantages of the curved volute structure in terms of aerodynamic and acoustic performance,providing theoretical basis and structural design methods for the development of high-efficiency,low-noise centrifugal fans.
Theoretical analysis and experimental research on multi system heat pump defrosting of air-cooled frost free refrigeratorAbstract: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.
Numerical simulation-based analysis and study of moisture conditions in air conditioner human presence sensor boxesAbstract: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.
Investigation into the fluid performance of reciprocating compressors with different suction designsAbstract: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.
Application analysis of microchannel heat exchanger on enamel outer-coil heat pump water heaterAbstract: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.
The research and exploration of cross-domain agent interaction technology for smart home and smart cockpitAbstract: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.
Empirical research on the effect of compound biological enzymes in removing odors from refrigerators:sensory evaluation based on real user environmentsAbstract: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.
Research on the heating reliability of rooftop air conditionerAbstract: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.
Data-driven detection method of refrigerator door-ajar eventsAbstract: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.
Research and application of infrared human sensing technology in indoor air conditioning unitsAbstract: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.
A study on layout optimization algorithm for home appliances and furniture based on prior knowledge and PSOAbstract: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.
Interpretation of the test method for wool fabric drying performance of household tumble dryersAbstract: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.
Study on synergistic control strategy for air conditioners based on frost point judgment and active frost suppressionAbstract: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.
Experimental research on energy efficiency grade of light commercial refrigerating appliance under GB 26920-2024 StandardAbstract: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.
Development of R290 compressor for 1.5 HP air conditioningAbstract: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.