The three types of Cu-P based brazing alloys with macrosegregation, fusion impurities or imperfect microstructures were prepared by controlling processing parameters, to research the influence of microstructure defects of on the characters of solders and welding quality, research influence of microstructure defects of Cu-P based brazing alloys to characters and enrich the assessment methods of material factors affecting welding quality. Optical microscope (OM), different scanning calorimetry (DSC), microhardness tests were used to study the influence of different defect levels on properties of brazing filler metals. The liquidus temperature and the crystallization temperature range of samples reduce with the reduction of defect level under the same defect type. The microhardness of copper-rich location is lower than normal location in macrosegregation samples of extrusion condition. The size of the microstructure has no effect on the porosity, but slag inclusion and segregation cause the bigger porosity, and the porosity decreases with the decrease of the defect degree of the solder sample.

The damping rubber made by chlorinated butyl rubber has a high damping coefficient in the range of -40℃~60℃, and the damping foot pad prepared by it has a good damping effect, especially in the low frequency range between 10 Hz~70 Hz, the maximum amplitude of the compressor piping can be reduced by 63% compared with the existing EPDM foot pad.

In this paper, the preparation of an easy-to clean coating and its application on glass shelf and glass panel on a refrigerator is investigated. Taking the easy-to-clean effect of the glass surface and the appearance of the coating surface as the evaluation criteria, the curing effect with different coating methods, conditions and different curing temperatures on the easy-to-clean coating was explored. The results show that the super-hydrophobic coating has the feasibility of application, especially a broad prospect in appliances, such as refrigerators.

The influence of the residual stress with different molding process parameters in polycarbonate (PC) component was researched, a model of household air-conditioning panel was choosed as the object of the study, the Moldflow software simulation as the analysis platform. The result shows that in the normal injection parameter range, higher mold temperature, lower holding pressure, and annealing treatment help reduce the residual stress of PC injection molded parts.

A UV varnish suitable for coating on thermoplastic silver powder primers was prepared by using polyurethane acrylic acid with six functions and two functions as prepolymers, dipentaerythritol hexaacrylate (DPHA) and tricyclodecane dimethanol diacrylate (DCPDA) as photosensitive monomers, and 1-hydroxycyclohexyl phenyl ketone (184) as photoinitiator, and the effects of the ratio of DPHA to DCPDA on the hardness, adhesion, water resistance, gloss, high and low temperature impact properties of UV varnish were had studied. The results showed that the ratio of DPHA/DCPDA had a great influence on UV varnish performance. With the increase of DPHA/DCPDA ratio, the hardness of UV varnish increased from HB to 2H, the adhesion decreased from grade 0 to grade 2, and the gloss decreased from 109 GU to 93 GU. When DPHA /DCPDA ratio was 1∶3, the adhesion, water resistance and high and low temperature impact performance of UV varnish reached the best.

The properties of different kinds of polyurethane-typed conformal coating products were studied. The basic performances, they were at the same level, such as the similar flame retardancy and electrical insulation under normal conditions, so it is unable to determine the best applicable situation. Thus, a series of environmental experiments were carried out, such as neutral salt spray test, thermal shock test and constant temperature and humidity test. During the environmental test, the electrical performance and change in appearance of different periods were recorded and analyzed. Through the analysis of the comprehensive performances of the products, the best applicable environments and regions are optimally selected.

The forked three-way stamping parts are commonly components used in the air collector pipe of the air conditioning unit. They mainly function is shunt, combined flow and filtration in the pipeline system. Filtering net is added in the internal three-way, fixed through positioning concave rings where the impurities can be filtered. The traditional stamping mould structure has its limitations, the failure of the pipeline parts is analyzed through experimental data, there is a phenomenon of stress concentration due to the irregular surface shape. To design the mould as an elliptical rotating shell body, changing its structure can effectively reduce the stress concentration. Starting from the processing technology of stamping parts, analyze the failure form of the fork tee parts, optimize the original structure of the tee stamping parts, increase the stamping distance value, and increase the wall thickness to improve the strength of the stress point. Through the above optimization and verification with the finite element simulation and experiment, it can be concluded that the modified stamping parts have a longer life and can withstand greater stress.

Axial-flow blade of outdoor air conditioner is a moving part, which is in high or low temperature environment for a long time. It is required that the blade should be with high stretched strength, high bending strength, good heat resistance, and low linear expansion coefficient, so as to ensure the stability of the air conditioner. Glass fiber reinforced AS materials are widely used in industry, but glass fiber reinforced AS is brittle, its performance and the improvement space of rubber toughening is limited, and it is easy to cause blade fracture in assembly production and transshipment of the air conditioner. Demonstrated the feasibility of using composite reinforced PP instead of glass fiber reinforced AS material in small diameter and low pressure Axial-flow blades from the aspects of material mechanical properties, monomer type test, natural frequency, air volume, noise, vibration and long-term operation reliability. The results show that the composite reinforced PP is used instead of AS-GF20 in the Axial-flow blade with the specification of φ320×118. The weight of the blade fell by 14.2%, about 41 grams per blade. The performance and reliability of the blade achieve quality requirements of bulk-production.

Spiral design of scroll compressor plays an important role in compressor performance and reliability. In order to study the advantages of algebraic spirals, the meaning of algebraic spirals and wall thickness can be easily understood through geometric derivation and principle introduction. Through the theoretical calculation and experimental comparison of the algebraic spiral scroll product and the circular involute scroll product, it is concluded that the algebraic spiral has some obvious advantages. Algebraic spiral is a variable wall thickness structure that enhances the reliability by changing the vortex strength. Under certain conditions of inspiratory volume, compressor performance can be improved.

The structure of the heat exchanger of the room air conditioner is becoming more and more compact. At the same time, the demand for the refrigeration capacity is increasing. It is very important to ensure that the air conditioner can give full play to its refrigeration capacity and operate reliably by analyzing the thermal properties of the refrigerant, reasonably adjusting and setting the parameters of the refrigeration system. Theoretically and experimentally analyzes the change of system operation characteristics with outdoor air volume when the room air conditioner in R32 refrigerant is at high frequency output. The change of air volume affects the change of system pressure and refrigerant flow. Excessive external air volume causes low evaporation temperature and overheating. Part of the area in the evaporator is superheated gas, the effective heat exchange area becomes smaller, and the refrigeration capacity of the system decreases. In the actual design and commissioning of the refrigeration system, it is necessary to adjust the temperature difference between the inlet and outlet of the indoor evaporator reasonably to achieve the optimal operation of the system.

In recent years, smart home products have gradually entered our daily life. The bathroom is an important part of the smart home, but there are few solutions on the market for smart bathroom systems. At the same time, meeting user needs is the key to a good experience. Based on the user needs of smart bathroom system design, mainly focuses on the investigation and analysis of the needs of different user groups, smart bathroom system architecture and scenario settings, to provide guidance for the follow-up smart bathroom system design.

In order to study the reason of IPM ESD failure and put forward the method to solve the ESD problem, the theoretical analysis and experimental verification of ESD loop are carried out. Because there is an ESD diode structure inside the driving IC, it will cause ESD voltage to be transmitted to the gate of IGBT through the ESD diode inside the driving IC when ESD is applied on one or two pins of IPM, resulting in IPM ESD failure.

Introduces the structure characteristics and working principle of a remote control automatic identification and reliability test equipment, which adopts the manipulator and servo drive system as the mechanical system and the CCD camera of ARTRAY company as the visual acquisition system. Overall system include the design of clamping test-bed, seat ring reliability test module, flip cover reliability test module, data recording module, calibration plate, template setting, shape matching, manipulator operation and other major hardware. The test software is compiled by computer language to realize the communication and control between PC and PLC. After analysis, comparison and practical application, the existing equipment has greatly improved the detection efficiency and the accuracy of the inspection results, the effective application of the equipment will promote the development of the intelligent toilet industry.

This work studies the power loss of full-SiC intelligent power module, hybrid-SiC intelligent power module and Si intelligent power module. The experimental results show that the energy loss of full-SiC module IPM-1 is the lowest; the power loss of full-Si module IPM-4 is the highest; the power loss of only replacing switch devices with SiC-MOS is lower than that of only replacing Si-FRD with SiC-SBD; the power loss relationship is IPM-1 (SiC-MOS+SiC-SBD) < IPM-2 (SiC-MOS+Si-FRD) < IPM-3 (Si-IGBT+SiC-SBD) < IPM-4 (Si-IGBT+Si-FRD). The power loss of SiC IPM decreases with the decrease of gate resistance and decreases with the increase of gate voltage of SiC-MOS. The power loss of SiC IPM can be further reduced by properly reducing the gate resistance and increasing the gate voltage. The power loss of full-SiC intelligent power module can be reduced up to 40%.

Starting from the basic concept and principle of electrical strength test, expounds the test object, tripping current, insulation resistance and test method, answers some common problems of electrical strength test, explains the easily misunderstood places, further makes clear the requirements of electrical strength test, clarifies the concept and principle of the test.

In order to improve the quality of enamel units enamel tank for storage water heaters, refer to the relevant enamel standards in Germany and Australia, and run a comparative method, compared with the original standard these contents of "standard name and scope of application, cathodic protection, adhesion requirements and test methods, hot water erosion resistance requirements and test methods, alkali resistance test methods, testing regulations" are introduced and analyzed in detail, emphasizing the "ratio of sacrifice anode quality to enamel area" and "changes of test methods and weightlessness requirements for hot water erosion resistance" the purpose is to arouse the great attention of water heaters companies, and to do all the preparations before the standard version change in advance in accordance with the analysis content.

Starting from the research on the energy efficiency testing technology of electric ovens, this paper discusses the difficulties of the energy efficiency testing of electric oven. Based on the IEC 60350-1:2016 standard, taking the traditional heating function as an example, it explores the calculation process of the standard power consumption and heating time in detail. The proportion of the main components of the load block Hipor is found out, which is helpful to promote the research of heating load . This paper summarizes the overall design, experimental scheme and subject setting of IEC standard for reference, and put forward suggestions for improving energy efficiency and standard system.

Tightness is an important link in the reliability research of refrigerating system, especially the application of flammable refrigerant in refrigerating products is gradually maturing, it is extremely urgent to examine and judge the tightness level from the perspective of safety. Thus, a series of test methods and requirements of ISO 14903-2017 on the tightness of refrigerating systems are introduced.

The lean manufacturing process review play an important position in the new product development process. In the product design stage, through of the lean manufacturing process review can reduce molds replacement, shorten the time of the new product introduction, improve the production efficiency and quality. Discusses the lean manufacturing process review of the air-conditioning, can provide the review experience for industry designers and process reviewers.

Introducing the definition and classification of electromagnetic radiation, and discussing the possible effects of electromagnetic radiation. The working principle of the induction cooker is briefly described, the test method of electromagnetic radiation of induction cooker is introduced emphatically, and the test results are analyzed by the examples of electromagnetic radiation test of induction cooker.

In order to study the cause of the failure of the electronic expansion valve coil under low temperature conditions, this study analyzed the relationship among injection molding process, winding structure, environmental condition and insulation wall thickness of electronic expansion valve coil. Thermal expansion and contraction cause the insulation layer to crack, and condensed water enters the tiny cracks of the coil, which reduces the insulation performance of the coil and causes the coil to fail.