Internal leakage is a typical failure mode for cut-off valves. It is necessary to evaluate the seal reliability under various stress conditions. There are several types of sealing pairs for cut-off valves. One of them is conical type, which is line contact initially and becomes surface contact while the material endures deformation with contact pressure when the valve is closed for the first time. The contact pressure of the sealing pair may drop or even the contact surfaces separate when the valve is loaded with excessive external force, leading to internal leakage. In this study, a cut-off valve of air conditioners is taken as example. Techniques are adopted to promote convergence such as meshing control, Arbitrary Lagrangian-Eulerian (ALE) adaptive meshing, and adding a little damping to the sealing pair. The sealing status is judged according to contact status and contact pressure distribution. The reason of internal leakage is analyzed according to the plastic strain distribution of the valve seat and its structure is strengthened.

The inner barrel of the drum washing machine depends on the two deep groove ball bearings support on the outer barrel, and the inner barrel is driven by the motor. During the washing stage, the inner barrel rotating at a low speed, the load from the low was brought to a higher position, and then at a certain angle was thrown out of the beat, to remove the stain; in the spin stage, the inner barrel rotates at a high speed, load and water separation under the action of centrifugal force. As the core component of the transmission, the bearing has been in a rotating state throughout the whole process of washing. In this paper, the service life of the bearing is calculated through the force analysis of the related components, which provides the basis for the selection of bearing.

Compressor is the main noise source of the refrigerator, because of the long wave and high energy, the low-mid-frequency noise is difficult to attenuate through the traditional sound insulation materials, It has become the bottleneck to limit the noise breakthrough of refrigerators. Different from traditional materials,acoustic metamaterials based on locally resonant principle,it is very suitable for low frequency noise reduction. Firstly, determined by the experiment,the noise around 600Hz is the radiated noise of the compressor,then, COMSOL was used to build the acoustic finite element model of the acoustic metamaterial. Finally, noise and performance experiments were carried out to assesse the effectiveness of these noise reduction methods. The experimental results show that the noise of the refrigerator is reduced by 3.6dB, and the sound quality of the refrigerator is improved obviously.

Electric heating tube has been in the complex cold and hot circulation environment for a long time, and it is easy to appear scaling and corrosion. In this paper, the mechanism of scaling and pitting corrosion of electric heating tube was analyzed through comparison of scale formation, corrosion resistance and other tests. The results show that the surface of the enamel electric heating tube has low surface energy, which makes the scale loose and not easy to adhere. When the enamel layer is in contact with the medium, a silicon oxide protective film is formed, which effectively prevents pitting and stress corrosion of the stainless steel tube body.

The influence of the distance that the iron core moves outward and stiffness coefficient of spring on the outlet pressure of the moving magnet gas ratio control valve, and the distance that the nut moves outward and stiffness coefficient of spring on the outlet pressure of the moving iron core gas ratio control valve was studied. The results showed, the outlet pressure of moving magnet gas ratio control valve under the low load working state increases obviously with the distance the core moves outward, but the outlet pressure under the high load working state has almost no influence. The outlet pressure of moving iron core gas ratio control valve under low load and high load working state decreases with the distance that the nut moves outward, and the variation is consistent. When the outlet pressure of the gas ratio control valve under the low load working state keeps the same, the outlet pressure of moving magnet gas ratio control valve under the high load working state decreases with the stiffness coefficient of spring, the outlet pressure of the moving iron core gas ratio control valve under the high load working state remains when the stiffness coefficient of spring increases.

The recycled high impact polystyrene (HIPS) was added into the injection grade new HIPS, and the properties of mixed HIPS were studied. The tensile strength, elongation at break and izod impact strength of mixed HIPS decreases with the increase of recycled HIPS ratios. The tensile strength, elongation at break and izod impact strength of mixed materials can be more than 85%, 85% and 75% of the new HIPS, respectively. The influence of recycled HIPS on the bending strength was not obvious, and the thermal deformation temperature of mixed HIPS is basically the same as that of the new material.

In this paper, ABS, HIPS, ABS+PC, PP and PC as raw materials for injection molding were studied to explore the effect of storage ambient temperature on their properties, that is, the change of color difference, long-term storage at low temperature and the change of temperature from low temperature recovery to room temperature were studied respectively. Influence. The results showed that the above raw materials were stored at 30℃ and 40℃ for 168h, color difference valueΔΔE<0.5, and at 50℃ for 168h, except PC/ABS color difference valueΔΔE<0.5, the other materials color difference valueΔE>1.0. The tensile strength and bending strength of the above raw materials were increased and elongation at break under the storage condition of low temperature -20℃. However, the mechanical properties of the above-mentioned materials remained basically unchanged after the process from low temperature to room temperature.

Based on a large number of experimental data of different operating states of water storage electric water heater, the paper calculates the initial remaining available equivalent bath water and the increasing rate of equivalents bath water by using neural network method, and iteratively updates the remaining available equivalent bath water by calculating the online equivalent bath water consumption rate. The remaining bathing time can be estimated by the quotient of the difference between the equivalent bathing water volume and the equivalent bathing water consumption rate and the increase rate of the equivalent bathing water volume.

Using high voltage electrostatic can form space electric field in wine cooler. To promote the association of molecules, the hydrogen bond and weak chemical bond in new wine can be destroyed by electric field. The electric field can also active the molecules in wine, and provide energy for oxidation、polymerization and esterification reactions. It can reduce the irritability of wine and enhance the aroma of wine in a short time.

This paper mainly introduces the design of a constant voltage circuit based on the high-end drive of PMOS and its application in the control circuit of water purifier intake booster pump. The constant voltage circuit introduced in this paper mainly includes MCU control circuit, PMOS high-end drive circuit, rectifier filter circuit and feedback signal detection circuit. This circuit intelligently adjusts the pressure of the water booster pump, optimizes the proportion of the clean-waste water, improves the amount of water output, saves energy and saves water by collecting and analyzing the feedback signal data.

The heating element and temperature detection technology of the traditional kitchen appliance porridge ceramic electric cooker are improved, which can realize the rapid heating and accurate temperature detection of the ceramic porridge pot, shortens the time of cooking porridge and improves the taste of porridge.

The temperature rise test of water solenoid valve is an indis-pensable item in the safety inspection of electronic toilet products, with the continuous promotion of the electronic toilet products, the study of resistance method to measure the temperature rise of water solenoid valve has far-reaching influence. This article starts with the examination of actual products, and it introduces the test procedure and data processing.

To verify whether the polyurethane can be filled in the refrigerator door and observe the volume fraction of the polyurethane at all times, a mathematical model of the flowing filling of polyurethane is established, where with the knowledge of computational fluid dynamics, the writer uses the pre-processing software to divide the actual door model of the refrigerator into grids, and uses fluent software to carry out numerical simulation of polyurethane injection and analysis of pure flow field. The results show that with the filling, the volume fraction of polyurethane increases and the volume fraction of air is gradually replaced. When at 61s or so, the volume fraction of polyurethane reaches the maximum, and polyurethane fills the whole body cavity of the refrigerator door, when the filling process ends.

The effect of fin spacing on the heat transfer performance and pressure drop of fin and tube heat exchangers is studied in this paper. At present, the fin spacing of 5mm diameter is usually between 1.2mm and 1.3mm. The fin spacing can be reduced to 0.8mm to 1.0mm by means of compact design and machining. This paper mainly analyzes and compares the influence of fin pitch reduction on heat transfer capability and air pressure loss from theoretical analysis, three-dimensional modeling and fluent calculation. Under the same windward area and wind speed, with the decrease of fin spacing, the capacity increases gradually, but the pressure loss and power increase at the same time. It shows that the problem of air loss caused by fin infilling must be solved at the same time when the fin spacing decreases, effectively analyze the influence of contact thermal resistance. Otherwise, the heat transfer area can’t be fully utilized. This study can provide some references for fin design of heat exchangers.

Aiming at vibration problem on air-conditioner pipeline, it discussed the influence of pipeline modality by suction and exhaust pressure of the pipe on the air-conditioner. The result indicates that when considering the suction and discharge pressure, the natural frequencies of the pipeline with the same vibration characteristic increase correspondingly, that is pre-stress enhances stiffness of the pipeline; If the suction and discharge pressure of pipeline are not considered in pipeline modality analysis. it would miss some natural frequencies and misleading the pipeline improvement directions.

Based on the existing refrigeration system of household inverter air conditioning, this paper proposes to use refrigerant totake away the heat generated by outdoor electrical control when the whole machine is running in high temperature environment in summer, so as to reduce the temperature of outdoor electrical control module and improve the reliability of electronic control operation, and to run higher frequency at the same temperature of refrigeration environment, so as to improve the refrigeration in high temperature environment in summer. Effectiveness, improve user satisfaction. In practical application, the effect of refrigerant cooling scheme on high temperature refrigeration effect of inverter air conditioning and the temperature of outdoor electrical control module are analyzed and compared, which provides new research ideas and directions for inverter air conditioning products.

This paper aims at the dehumidifier water full protection mechanism reliability Design, application 6sigma technology analysis, from the DMADV five stages(Define, Measure, Analyze, Design and Verify) analysis, re-design, re-verify to solve the problem of empty tank alarm, and ensure our dehumidifier products water full protection mechanism modular design reliability.

This paper based on the standards proposes a performance test device for water-source heat pump that meets on-site measurements. It can automatically collect and process test data, then generate test reports. The analysis results of performance comparison test show that the device has stable performance and high reliability. The device with compact structure is easy to operate, light and portable, so it can greatly improve the test efficiency.

The actual state of the commercial circulating heat pump hot water heater during the initial startup to heating process has a certain impact on the performance index of the hot water heater. However, the performance standard GB/T 21362-2008 "heat pump hot water heater for commercial or industrial use and similar purposes" does not clearly specify the requirements of the product startup test state. There are certain differences in the methods used by different institutions in the test and research process, and how this difference affects the product performance evaluation. In this paper, different initial heating temperatures are selected through the experimental method to make the commercial circulating heat pump hot water heater work under different initial conditions, and then study the trend of its influence on the performance of commercial circulating heat pump hot water heater, and discuss the possible applications for testing.

At this stage, with the improvement of the economic environment, people's life quality has gradually improved, so the use of air conditioners has become more and more popular. However, safety are particularly important, especially the outdoor unit against the rain, which has always been a difficult and painful point in the industry. The waterproof performance of the air conditioner is one of the important factors in electrical safety. An effective waterproof structure plays a vital role. This paper analyzes the shortcomings of the existing waterproof structure of air conditioners and proposes a new waterproof structure.

In order to analyze the influence of domestic tumble laundering on denim fabric, three common fabrics were selected as the research objects in this paper. The effects of different washing times on the air permeability, stiffness, color fastness to friction, tear strength and tensile properties of denim fabrics are discussed. It can provide guidance on washing care of denim garment for consumers. The results show that, washing has little effect on the physical properties of denim fabric on the whole, so consumers can wash normally. The effect on the appearance and comfort of the fabric is more obvious, which is mainly reflected in two aspects: easy fading and poor air permeability. The air permeability of 10 times of washing is worse than that of 20 times of washing. With the increase of washing times, the physical properties of the denim fabric with spandex added have a greater change, so it is suggested to wash less for this kind of apparel.

This article mainly studies the effect of different steam temperature and steam flow rate on the structure of steamed bread. Tests have shown that steam temperature, steam volume and steaming time all have a great influence on the quality of steamed bread. With the increase of steam volume, the uniformity of steamed bread structure development is improved, but with the increase of steam temperature, steamed bread taste is improved. The range is not large, although the superheated steam has little effect on the taste of steamed bread, the effect of overheating and high temperature steamed starch is good and the sweetness of steamed bread is improved.

This paper briefly describes the existing washing and maintenance problems of the washing machine and the defects of the existing technology, finds out the user's needs and the development direction of the industry, and proposes the technology of waterless washing between the inner and outer barrels to achieve healthy care, mainly introduces the waterless washing technology between the inner and outer barrels. The principle and the innovation of the key sealing technology in the realization process solve the problem of health care that can not be achieved by the existing washing machine, effectively avoid the secondary pollution in the washing process of the clothes, and meet the needs of the user's health care.