Journal of Appliance Science & Technology was founded in 1981, sofar has gone through a journey of 40 years. In the past 40 years, "Journal of Appliance Science & Technology" based on science and technology actively serving the technological innovation and technological progress of the home appliance industry, promoting the construction of industry standardization persistently, and striving to speak out for the industry's innovative scientific and technological achievements. In the past 40 years, "Journal of Appliance Science & Technology" has been based on quality, has strengthened the standardization and standardization of journal, introduced modern publishing methods, strictly prevented academic misconduct, and improved communication capabilities in multiple dimensions. In the past 40 years, "Journal of Appliance Science & Technology" has been proud of its team, relying on the editorial committee and council to run the journal, continuously expanding the team of domestic and foreign experts, and improving the technical level of the editors. The initial mind such as a rock, and the mission is on the shoulder. "Journal of Appliance Science & Technology" will continue to record and disseminate technological progress of industry as its own responsibility, and work hard towards the goal of boosting the innovation and development of the home appliance industry.

We introduce some concepts for designing robotic vacuum cleaners. Some main algorithms for environment modeling and path planning are introduced. Each algorithm is described in details. A case study is given. An information-gain based path planning algorithm for robotic vacuum cleaners is proposed which considers sensor uncertainties. The proposed method reduces the entropy and maximize the likelihood of cleaning the entire room.

Defrosting of air-cooled refrigerator evaporator is heated by heating wire to melt the ice on the evaporator into water, which is discharged to the evaporating dish for evaporation. After defrosting, in order to make the refrigerator room warm quickly, the compressor and fan usually run at the highest speed. The sound of compressor and fan running at high speed is much louder than that of normal operation. This kind of sound is easy to be perceived by the user at night when the user is resting, which directly affects the user's sleep. Therefore, it is necessary to adjust the time of high speed of compressor and fan to avoid the rest period of users. First of all, the user's rest period is intelligently identified, and then the silence mode is entered. Through the control logic of the main control board, the rotation speed of the compressor and fan and the time of high frequency operation are adjusted, so as to achieve the purpose of refrigerator night silence.

The excellent performance in high efficiency and energy saving of refrigerator system is grounded on a well-designed heat exchanger. Based on the application background of heat exchanger in refrigerators, the most promising technology of refrigerator heat exchangers were investigated, including microchannel heat transfer, PCM, rotary heat transfer, grooved tube and far-infrared coating. Besides, as for the current issues of heat transfer enhancement, defrosting control and test-bench construction, this review summaries some latest research methods and solutions.

With consumers concerning about the sound quality of a refrigerator, the refrigerator compression sound quality, one of the main noise sources is more and more taken seriously by the compressor manufacturer. In this paper, a refrigerator compressor is chosen as the research object, the sound quality analysis method is used, and the customer's most concerned sound "buzz" and "shrill" is subjectively evaluation and objectively tested. And the relationship is established between the subjective and objective results. The research has shown that certain subjective feeling can be characterized through objective acoustic quality index, this result lays foundation for the rapid assessment and improve of the sound quality in the future.

Household appliances have become an indispensable living product in more and more families. At the same time, people are paying more and more attention to the health problems caused by the growth of bacteria during the use of appliances. Therefore, the antibacterial effect of household appliances has become one of the indicators of public judgment. Because of its low cost and good antibacterial effect, nanomaterials can be used as one of the ways to solve this problem. Analyzes and studies three kinds of nanomaterials which have been preliminarily applied in home appliance industry with low cost, no additional harsh conditions and good antibacterial effect, and points out that the development of more excellent nanomaterials is the hot spot in the current antibacterial industry.

Evaluate the fresh-keeping effect of hypobaric storage on aquatic products. Five aquatic products of tuna, sturgeon, sea cucumber, lobster and abalone were used to evaluate the changes in weight loss under reduced pressure storage conditions (set pressure at 80 kPa) and normal storage conditions. Then selected tuna to evaluate its texture, chromatic aberration, colonies number, TVB-N, electron microscope and light microscope. Under hypobaric storage, the weight loss rate of the five aquatic products is relatively low. Among them, the increase in the rate of inhibiting sea cucumber weight loss is the most significant. The hypobaric storage for 7 days is 7 times lower than that of ordinary refrigerator storage. It has better preservation effect on tuna. The hypobaric storage can delay the growth of the colonies number and TVB-N value, and extend the preservation period of 4 days. The same results of electron microscopy and light microscopy can extend the preservation period of 2 days. Prove that hypobaric storage can have a better preservation effect on aquatic products.

The non-contact recognition technology of fabric components provides the possibility to realize the intelligent laundering of clothing, which can also realize energy saving and water saving during the laundering of clothing. Near-infrared spectroscopy technology can accurately identify fabric components, realizing new applications in the field of intelligent laundering. By introducing the application of near-infrared spectroscopy technology in fabric component recognition, analyzes and summarizes the feasibility of this technology in clothing stain recognition, bacteria recognition and fabric dye recognition, and puts forward suggestions for current problems. Summarize the application prospects of near-infrared spectroscopy technology in the field of fabric intelligent laundering, and provide a reference for the combination of washing machine and near-infrared spectroscopy technology.

With the development of heating technology, traditional cooking appliances can't obtain high-quality cooking needs; Solid-state sources are used as energy generating devices in new-type RF cooking appliances. Especially the power chip will generate a lot of heat loss in the RF circuit during the operation of solid-state sources, if these heat losses can't be dissipated in time, it will affect the efficiency and reliability of the chip, and reduce the performance indicators of the solid-state source. This paper proposes a high-efficiency double-layer drainage heat dissipation solution, which adopts an unbalanced ratio upper and lower high-efficiency synchronous heat dissipation technology, local copper embedding, and a high-volume, low-noise streamlined air duct design, which reduces the temperature of the power chip substrate by 41°C, it aims to achieve a more efficient heat dissipation design.

The performance test standards of drinking water treatment plant between China and American are compared. The Chinese reference standards are GB/T 30307, GB/T 35937, GB/T 17218 and the sanitary code issued by the Ministry of Health, and the American reference standard is NSF/ANSI 42/53/61/600. Both of them belong to national standards. The national standard focuses on the preciseness and reproducibility of the test method. Considering the wide range of pollutants, the implementation index requirements are relatively strict. The American Standard simulates people's water habits in daily life, and the test methods fit the actual use, and the coverage of organic pollutants is very wide. By comparing and expounding the standards of the two countries from the aspects of structural performance, health safety and general performance requirements test. On this basis, the paper puts forward the reference points in the process of standard formulation of drinking water treatment plant in China.

Switching power supply has been widely used in many fields, and the high frequency characteristics of switching power supply lead to serious interference problems. If the relationship between single component and EMI can be made clear in design, and then EMI control of switching power supply can be achieved by parameter control, it will play a great role in the development and design of switching power supply. In this paper, the author takes EMI modeling and suppression method analysis of flyback switching power supply as the breakthrough point, analyzes the equivalent model of transformer, obtains the influence mechanism of transformer parasitic capacitance on disturbance voltage, proposes an EMI suppression method to compensate transformer parasitic capacitance by adding capacitance, and verifies the effectiveness of this method by experiments.

Smart household appliances system consists of three parts: control terminal, device side and cloud. The smart household appliance management unit runs between the device side and the cloud. Its functions include not only connecting all sub-devices which interface types include ZigBee, Wi-Fi, RS232, RS485, UART, etc, but also connectintg the cloud. The unit can establishing a long-term connection with the cloud which enables the sub-devices to register in the cloud, log in, reporting status data and getting commands from the client. The smart household appliance management unit integrates modules such as low-level device drivers, protocol analysis and cloud interaction, which not only realizes the data transmission between LAN and WAN, and the multi-protocol interoperation between sub-devices, but also implements the function of device management such as device registration, cancellation, login, logout, etc.

In order to promote the energy saving and emission reduction, this paper analyzes the current situation of cleaner production based on the main process flow and the important production and emission links in the production process of household electrical appliances industry in China. Based on the in-depth research of the main household electrical appliances enterprises, the paper develops the assessment indicator system of cleaner production, in order to encourage enterprises to actively carry out technological upgrading and transformation and pay more attention to the cleaner production, provides standard technical support for the effective implementation of cleaner production audit in household electrical appliances industry.

The group standard T/CAS 342-2020 was published and implemented, standby power, dehumidification time and dehumidification area and noise were introduced are added in the standard, especially the test items such as standby power, dehumidification time and the quantitative calculation of recommended dehumidification area are the first time in the dehumidifier standard. The different standby modes of the dehumidifiers were analyzed, the standby power test were also carried on the representative models and the test data were analyzed, so that the related personnel can understand the status of the standby power on dehumidifiers. Finally the key points that should be understood were given to facilitate the relevant personnel to understand the standard.

After decades of rapid development, the construction technology of air conditioner laboratory has become increasingly mature, but contractors often to save costs, and reduce the promotion and application of new energy-saving technology, which seriously hinder the development and promotion of new energy-saving technology, resulting in air conditioner laboratory energy consumption is still at the level of 10 years ago.To air conditioner laboratory development towards a higher level, through the analysis of industry air conditioner laboratory conditions, introduce the new energy-saving technology and the effect of air conditioner laboratory, discusses measures to promote energy-saving hierarchies, and put forward the balance of energy efficiency in the operation of the air conditioner laboratory and experimental efficiency concept, hope to promote the development of new energy-saving air conditioner laboratory technology, promote industry standards.

Based on the user's demand for a larger volume of refrigerator, reducing the insulation layer has become the most effective way to rapidly increase the volume. However, in the face of the attenuation of thermal insulation performance caused by the reduction of insulation layer, how to solve the condensation problem caused by the outward transfer of cold volume in the refrigerator room still needs to be studied. Based on the existing anti-condensation measures, a variety of pre-designed schemes were developed. With the help of simulation tool Icepak, each scheme was modeled, boundary condition setting, temperature field simulation, and feasible schemes were screened out; according to the simulation results of the targeted prototype for experimental verification, and then get an effective anti-condensation scheme; finally, these schemes are further compared to select the most appropriate scheme from the direction of manufacturing process, power consumption and so on. In this way, it can avoid the way of making prototype for all schemes at the beginning and then verifying them, shorten the verification cycle, and help the design side to determine the optimal scheme.

As a natural medium, R290 has become the trend choice in the refrigerant substitution process because of its excellent thermodynamic performance. Through the performance test of R290 compressor under different standard test conditions, it can be seen that the change of test conditions has obvious influence on the difference of compressor refrigeration capacity and COP. The performance distribution characteristics of 40 R290 compressors under the national standard were studied. Compared with R600a compressors, R290 compressor is also excellent in performance grade in performance grade.

Taking a rolling rotor compressor as the research object, based on the theory of lubricating oil viscous lubrication and the power loss of refrigerant leakage theoretical calculation and experimental verification data, using the correlation theory to carry out the correlation between the assembly gap matching and binning in the manufacturing process and the performance impact analyze, obtain the principal component contribution rate distribution and its load matrix It was found that the cumulative contribution rate of the first 1-4 main components reached 71.1%. The main factors affecting the leakage of the refrigerant are the mechanical drive precision and efficiency of the pump body assembly, the concentric accuracy and volume rate of the pump body, the plane accuracy and the frictional power consumption, and the impact on the refrigerant. The contribution of the cooling capacity loss caused by internal leakage is 33%, 21% and 17.1% respectively. And obtain the process key assembly parameters and control schemes of the key parts of the compressor pump body.

Focuses on a certain refrigerator to reduce the energy consumption of the refrigerator through the application of energy valve. The effects of different ambient temperatures, valve leakage, and delayed compressor opening time on the reduction of energy consumption are verified. In addition, the solenoid valve is closed before defrosting so that the remaining refrigerant in the evaporator is extracted to reduce defrosting energy consumption and optimize the energy efficiency of the whole machine. The results show that: 1. The range of pressure reduction on the high pressure side at different ambient temperatures is similar, and the improvement of energy consumption by the pressure holding valve is not much different; 2. The shorter the valve opening time is, the more beneficial the energy consumption; 3. The valve leakage decreases and increases The energy-saving effect of the pressure-maintaining valve; 4. When defrosting, the valve is closed and evacuated to reduce the amount of refrigerant in the evaporator and reduce the heat loss absorbed by the refrigerant, which can shorten the defrosting time by 0.5 min and improve the energy consumption by 0.4%. In summary, take Midea two-door BCD360 refrigerator as an example, add energy valve with a leakage of 0.004 L/min, and the control logic is set to close synchronously with the compressor, and the compressor is opened 2 minutes before starting, and the valve is closed before defrosting, After the compressor runs for 0.5 minutes, the heating wire works, and the power consumption is reduced by 0.0359 kW•h in 24 h, which is 4.15% improvement in energy consumption compared to the original machine.

Aiming at the back cover of the mobile phone connected by the back glue, the automatic and nondestructive disassembly of the back cover of the mobile phone is realized. The device uses HX711 to detect whether the electric gripper clamps the mobile phone, DS18B20 to detect the temperature, and TB6560AHQ to control the forward and reverse of the motor. During the process, LCD1602 displays the working status of disassembly with timing function and alarm device reminder. At the same time, the process of heating and dismantling is simulated by finite element method. In order to ensure the accuracy of temperature control system, variable parameter PID algorithm is adopted. Finally, through the analysis of the experiment, the efficient and reliable disassembling effect is obtained.