On the basis of comprehensive analysis of heat pipe technology and inverter and VRF technology, A new heat pipe air condition system is proposed, The prototype experiment is carried out, the results shows: The new heat pipe air condition system directly conveys refrigerant into data room, which resolves the risk of water entering the data room, solves the problem of low efficiency of multiple heat transfer, improves the evaporation temperature of the system and expands the utilization time of free cooling; The new heat pipe air condition system can switch different operation modes according to outdoor temperature and indoor load,it has simple structure and high reliability; The new heat pipe air condition system makes full use of free cooling source, takes advantage of high COP and low cost of liquid heat pipe, The AEER is much higher than that of conventional Crac; The new heat pipe air condition system overcomes the shortage of low COP of magnetic suspension compressor, solves the problems of low pressure ratio energy regulation and non-uniformity of multi-terminal liquid separation, compensates insufficient pressure head at low pressure ratio, with the application of regional energy saving means such as air cooling, water cooling and evaporative cooling, it provides a new thinking and direction for cooling large data centers all year round.

Environmental protection alternative refrigerant has been widely promoted, at the same time, the operating environment of the air conditioner is getting worse under some special working conditions ,the demand of air conditioner which can operate efficiently under high temperature condition is increasing day by day. Three alternative refrigerants R410A, R32 and R290 are compared in high temperature physical properties, and in the same configuration of split room air conditioner refrigeration system, R410A, R32 and R290 are respectively charged to test the high temperature refrigeration capacity above 60℃ in the air-enthalpy test room. The results show that R290 is superior to R32 and R410A in capacity and energy efficiency at high temperature, the exhaust temperature is low and the system is reliable. It has a good application prospect in the middle and high temperature area.

The effect of electric field on the fresh-keeping effect of reheating dishes in refrigerators was studied, and the optimal field distribution area of reheating dishes was explored. The experimental results show that the electric field environment of the refrigerator has a significant effect on the changes of microorganisms, respiratory intensity and color during the storage of the sirloin. In general, the second layer of the electric field refrigerator fresh-keeping layer (S2, about 40cm away from the electric field preservation power supply, the electric field intensity distribution range is about 50-300v/m), the sample has the best fresh-keeping effect, and is more suitable for inhibiting the microorganisms of the reheating dishes.

The effect of electric field on the fresh-keeping effect of refrigerator fruits and vegetables was studied, and the optimal field distribution area of fruit and vegetable preservation was explored. The experimental results show that the electric field environment of the refrigerator has a significant effect on the storage loss, respiratory intensity and color change during the storage of rapeseed and tomatoes. In general, the second layer of the electric field refrigerator fresh-keeping layer (S2, about 40cm away from the electric field preservation power supply, the electric field intensity distribution range is about 50~300v/m), the sample has the best fresh-keeping effect, and is more suitable for storing fruits and vegetables in a short period of time.

Heat dissipation has become a bottleneck problem in the design of air conditioning motherboards and unreasonable heat dissipation causes the motherboard to burn out. At present, the design of the radiator is mainly based on experience and actual measurement, the key influence parameters of the radiator are insufficiently understood, and the design is blind. Takes an inverter air conditioner as the research object, and uses Ansys-Icepak to establish the heat dissipation simulation method. Through the actual measurement, the influence of the heat sink substrate thickness, fin height, fin spacing and other key parameters on the heat dissipation effect is deeply studied. The results show that the simulation analysis method is consistent with the measured trend, which can guide the design and improve the design efficiency. Fin spacing and substrate thickness should not be too large or too small, due to cost and space constraints, the fin length cannot be too long. When the fin pitch is 4~6mm, the substrate thickness is 5~7mm, and the fin length is 50~70mm, it is an optimal heat sink.

Based on the analysis of the mechanism of abnormal noise caused by thermal expansion, cooling and contraction, two practical and effective modification schemes are obtained: (1) Optimizing the local structure of the base, middle frame and left and right sweeper blades to change the contact mode from surface-to-surface contact to line-to-surface contact, and reducing the contact area by 98% compared with an old shell; (2) Optimizing the bottom, the process of pressing the seat parts and exerting pressure by hand, the base will not be separated from the base foam before the base foam is damaged, and the qualified rate is 100%. Through the above two rectification schemes, the qualified rate of hot expansion and cold contraction products is 100% and the complaint after sale is effectively avoided.

Finite Element Method (FEM) is used to calculate the modal of the air-conditionpipe, and modal testingis carried out to verify the accuracy of the simulation .The strain of the pipeline is also gained,and identify the dangerous modal by analysing the relationship between the modal and the strain.This provide some reference for the optimize design of the pipeline.

Iintroduces the proposal in detail from three aspects: the specific requirements of the proposal, the differences between the proposal and the current standards, and the analysis of the current situation of the industry. The writer hopes that through the introduction, the relevant personnel in the refrigerators industry can understand the trends of international standards as early as possible and can respond to the changes of international standards in time.

As a kind of heating source, air source heat pump has the characteristics of high efficiency and energy saving, and is widely used in the national “coal to electricity” project. By comparing and analyzing different heating sources, and comparing different types of household heating terminals, combined with the characteristics of air source heat pump operation, this paper recommends the solution of using air source heat pump + hot water tank + floor radiant heating + domestic hot water + cold tank + fan coil air conditioning. It has certain reference value for the selection of product mix for household and similar purposes.

The effect of cooling time of evaporation source between layers and the performance of LED chip in vacuum evaporation process using Cr/Ti/Al structure as metal P electrode in red light conventional forward structure of LED chip is introduced. The cooling time of different evaporating plating sources between Cr/Ti and Ti/Al shows that for single-layer Cr/Ti or double-layer Cr/Ti and Ti/Al, the cooling time of evaporating plating sources can be shortened to a certain time, which can effectively reduce the voltage of LED chips in the production process, but has little effect on the brightness, indicating the interlayer boundary. Surface resistance is affected to some extent by the source cooling time.

The bare-element type instantaneous water heaters (hereinafter referred to as the bare wire water heater) is a product that is directly heated by being immersed in water without insulated electric components. Because of its small size, high thermal efficiency, non-fouling, and easy to use, its share in the domestic market is also increasing. The heating element of the bare wire water heater is in direct contact with water, and it is completely dependent on the resistance and ground of the water to provide protection. The article takes a single-phase class I standing bare wire water heater as an example to discuss the standard requirements and test methods for leakage current. Bare wire water heaters should be designed and manufactured in accordance with the relevant TC04 resolution requirements to ensure that the resistivity of water flowing through the water heater does not decrease to the product's explicit requirements when used under different water qualities. When the water supply resistivity decreases to the explicit requirements, the bare water heaters can provide appropriate measures (or devices) to prevent possible dangers caused by them.

With the improvement of economic environment, people's quality of life is gradually improving, and the use of air conditioning is becoming more and more popular. People pay more and more attention to the safety of air conditioning, especially the fire prevention of internal machines, which has always been a difficult and painful point in the air conditioning industry. The fireproof performance of the air conditioner is one of the important factors in electrical safety. Effective fire prevention structure plays a vital role in fire prevention performance. Analyzes the current situation of the existing fire protection structure of the air conditioner inner unit and proposes a new fire protection structure.

The safety structure of a water heater powered by both photovoltaic-supply and mains supply should consider the safety isolation between the photovoltaic-supply and the live parts of mains supply circuit when the photovoltaic-supply is safety extra-low voltage. Necessity and realizing method of linkage disconnection of double-circuit thermal cut-out of dual power supply water heater. Cautions in design of control circuit of dual power supply water heater. Dual power supply water heater’s working mode.

Failure analysis for a household electric kettle of some brand with frequent short circuit was carried out. The short circuit was caused by the water from the leaking spout during use. The area around spout was analyzed by macroscopic examination, scanning electron microscope and energy dispersive spectrometry. The results show that the non-uniform filling of silica gel in part leads to the infiltration by water and accelerates the ageing of silica gel. The different expansion and contraction in the non-uniform parts of silica gel due to multiple thermal cycles in use, which leads to the stress tearing the silica gel, and ultimately leads to the local leakage. Finally, according to the results of failure analysis, some improvement suggestions are put forward to ensure the safety of consumers.

Washing is the most familiar way of washing in our daily life. With the improvement of people's living standard, people are no longer satisfied with simply washing clothes, and saving water and green is becoming a new concept of laundry. The techniques of waterless and water-saving washing are reviewed, and the advantages and disadvantages of each washing technology are listed.

Systematically analyzes the related research on the optimization of dryer parameters and the change of fabric performance after drying. It is concluded that the temperature of the heating wire and the mode of operation of the drum affect the mechanical properties of the fabric; the power of the heating wire, the humidity at which the program is stopped, the mode of operation of the drum, the duration of the cold air blowing, and the application of the added steam all contribute to the appearance of the fabric. The stage control of heating wire power, drum speed and air inlet rate can improve drying efficiency and reduce energy consumption. Provide theoretical basis for product innovation of dryer equipment and provide users with more effective textile drying care methods.

Uncertainty is an important index to evaluate the reliability of measurement results and evaluate laboratory testing ability. It is necessary to use scientific and reliable method to analyze uncertainty. Monte Carlo method is a numerical method to realize the propagation of probability distribution. It is more widely used than GUM method. Monte Carlo method is used to evaluate the uncertainty of the total pressure efficiency of the range hood. The standard uncertainty and the inclusion interval are given, and the results are compared with the traditional GUM method.

Based on a study on the motion equation of 1D spring oscillator and the work characteristics of the check valve, it is concluded that the flutter of the spool of valve is the main reason for the check valve producing humming noise; According to the mechanism of the humming noise of the check valve, the optimization of spool inlet flow field, spool guiding structure and spring stiffness of the check valve are considered to be the main ways for designing low noise check valve; The low noise check valve is designed by the optimization of spool inlet flow field and spool guiding structure, some analysis and tests are performed and the new check valve noise improvement is verified. The test results show that the new check valve noise is improved by about 3dB on the whole unit, which is improved by 7dB at the key peak frequency band of 160Hz, and the sound quality of unit improved significantly.

Based on the cettol6σ tolerance simulation technology, the simulation analysis of the appearance difference between the two ends of the air deflector of a new household wall-mounted air conditioner is carried out. Based on the air-conditioning solid model, the assembly constraints are based on the actual structural design scheme, and the dimensional tolerance definition is based on the part processing principle. The cettol6σ software is based on the principle of random sampling assembly for analysis and calculation. Through the contribution and sensitivity ranking table, the key influencing factors are refined, and the rectification and optimization scheme is formulated and verified based on this, and finally the problem of the matching surface aberration at both ends of the air deflector of the new product is solved.

Household disinfection cabinet is widely used at present in the kitchen of home appliances, but disinfection cabinet in the use of the lower bowl basket height difference exists, lifting laborious problems. Based on ADAMS to improve the disinfection cabinet floor frame lifting mechanism for dynamic simulation and analysis. In the simulation, the lifting process of the bowl basket is analyzed by introducing the air spring model. The results show that the improved lifting mechanism based on the parallelogram lifting mechanism and the gas-spring assisted mechanism can save energy during the lifting process and verify the feasibility of the mechanism design.