Formaldehyde has a negative impact on human health. In order to study the formaldehyde release content and release law in the refrigerator storage room, the formaldehyde content of the refrigerator storage room under different sealing time, different positions, and different working conditions was measured and analyzed by the phenol reagent method. The results show that the formaldehyde content in the storage room will gradually increase and reach saturation with the extension of the closed time of the refrigerator. In the saturated state, the content of formaldehyde in the refrigerator compartment is the highest, the freezing lower compartment is the second, and the freezing upper compartment is the lowest. Among them, the proportions of formaldehyde emission from box bladders, door seals, drawer panels and foams are relatively high. In addition, based on the human health threshold, a comprehensive analysis of the limit of formaldehyde in the refrigerator was carried out, and it was recommended that its content should be less than 0.1 mg/m³.

Steaming is a cooking method that utilizes high-temperature water vapor to heat ingredients. The changes of sensory qualities of ingredients, such as the color and texture, are the most significant characteristics before and after cooking, and also one of the most concerned qualities of researchers and developers of kitchen appliances. In order to figure out the influence of steaming on the sensory quality of ingredients and to promote the understanding of kitchen appliances technicians on the application of steam oven products, the factors, principles and characters of the changes of color and texture of different kinds of ingredients in the process of steaming were studied by summarizing domestic and foreign literatures. The review showed that the effects of steaming on the color and texture of vegetables, livestock and poultry meat and aquatic products showed characteristic differences among species, which provided a reference for the setting of steaming temperature and time in the steam oven.

Rigid polyurethane foams are typical thermal insulation materials widely used in different areas. The equivalent thermal conductivity of rigid polyurethane foams is closely related to the microstructures. Based on the SEM photographs of different rigid polyurethane foams, experimental tests and analysis results, the quantitative relationship between the thermal conductivity of rigid polyurethane foams and microscopic factors was studied by the Lattice Boltzmann numerical simulation method. Based on the results, an optimized scheme for the thermal insulation properties of rigid polyurethane foams was proposed.

The working lifetime and long-term stability of the electrochemical formaldehyde sensor greatly restrict its application in household appliances. Improving the working stability of internal core components is the key to solve the short working lifetime and poor resistance to harsh environment for the formaldehyde sensor. In this work, a formaldehyde sensor based on new electrolyte and anti-interference catalyst formulation is developed. The experimental scene test, anti-interference test, and life test of the formaldehyde sensor have been carried out. The results show that the designed and optimized new electrolyte and anti-interference catalyst formulation can effectively improve the long-term working stability and working lifetime of the sensor, and enhance the anti-interference capability of formaldehyde sensor against environmental gas pollutant sources. This work can play an important role in broadening the application of the electrochemical formaldehyde sensor in the household appliances.

Vibration could not only induce structural noise, but only determine the reliability of products. Particularly, abnormal vibration would influent UE. There is one T-shape range hood which is with serious vibration problem. The vibration of it is more than 150 micrometer which cannot meet the quality standard. This purpose of this research is to solve the vibration problem of this range hood by the method of modal analysis. Modal analysis can figure out the range hood parts which cause the abnormal vibration. Optimization would be done due to the Modal shapes and methods of solutions would be made. Verification of the final solutions will be implemented by combination of vibration frequency analysis and vibration tests.

Forced convection oven as a common baking tool, the uniformity of temperature field is an important index to measure its performance. Through the study of the uniformity of the temperature field of a dual fan convection oven, finds that: (1) Using Teflon blocks to simulate food, the variance of simulation is in good agreement with the experimental range, which can be used to reflect the temperature field uniformity of cavity; (2) Compared with the uniformity of temperature field of single fan cavity, the clockwise rotation of dual fans can increase about 30%; (3) In the dual fan cavity, left fan rotates clockwise and right fan rotates counterclockwise, the heating rate of the center of the cavity is increased by 17% compared with dual fans rotate clockwise. In addition, when left fan rotates clockwise and right fan rotates counterclockwise, the heat accumulation in the center area of the cavity can accelerate the cooking of large-volume food.

A real-time gesture control system based on still field is designed. The system includes four key modules: gesture detection sensor, MGC3130 controller chip, embedded Gest IC library and external electrode. The core MGC3130 controller is mainly composed of low-noise analog front-end, digital signal processing unit, communication interface and so on. It provides the ability to generate electric field transmitting signal, adjust receiving electrode analog signal, process data in digital form, and communicate with master control. The sensor of this system has one transmitting channel and five receiving channels with high sensitivity, which are used to detect the electric field distortion caused by capacitance change. The transmitting and receiving electric field electrodes are connected with the sending and receiving channels of the controller. The spatial distribution of the electrodes enables the chip to determine the center of gravity of the electric field distortion, track the user's gesture in the detection space, and complete the gesture recognition task. The recognition results are converted into the actual control commands of the air conditioner to realize the near-field gesture control function of the air conditioner.

Based on experimental method, the draught rating of pioneer air conditioner with cross flow fan at normal mode and low-draught mode was gained in Comfort Simulation Room, and the experimental results showed multiple jets at low-draught mode helped to reduce draught rating. The paper then utilize numerical method to analyze the internal flow of pioneer air conditioner, indicating a secondary air pressure increase happened within the whole domain of air diffuser in the front of the air deflector, and the energy at the diffuser was recycled as a result. The energy was then re-released by multiple jets, leading to not only an increase in the uniformity and wideness of air supply, but also an decrease of maximum flow velocity, and the draught rating of the room decreased. In the end, the paper discussed the mechanism of condensation production at both sides of air outlet by numerical method, which was finally utilized to optimize the air outlet structure, giving a solution to condensation phenomenon within low-draught mode at both sides of air outlet.

For the top loading washing machine, the motion of mounting system is firstly simplified to two degrees of freedom model, based on the analysis of the kinematic relationship, the mathematical model with two degrees of freedom is then derived by using D′Alembert principle and Lagrange method respectively. The equation of motion is solved and the amplitude-frequency curves for two degrees of freedom are drawn. At last the influence of balancer and suspension location on the tub vibration is studied. It provides one simple and convenient method for dynamic properties analysis of the front loading washing machine.

Starts from the principle of aerodynamic noise generation of range hoods, introduces the main causes of aerodynamic noise and the main solutions. The article summarizes the main noise sources of range hoods in the development process of range hoods, and how to judge the noise sources by finite element method. Computer simulation to judge the noise problem can avoid many design defects in the early stage of product development, reducing the time cost and capital cost of repeated proofing and trial production. The content summarized in the article provides a reference method for the subsequent development of range hoods and the solution of noise problems, it also provides ideas for solving noise problems for range hood developers.

Low ambient temperature air source heat pump (water chilling) package is mainly used for heating in northern China and cold winter. It is the main product of clean heating policy issued by the state in recent years. The main differences between the new edition and the previous one of GB / T 25127-2020 "Low ambient temperature air source heat pump (water chilling) package" series of national standards are described. The new edition of the standards have modified and supplemented some contents concerned by the industry. The main change is that the comprehensive performance coefficient is adjusted from IPLV to APF.

With the rapid development of the electronics industry, the integration of electronic products is getting higher and higher, and ion pollution tests are increasingly appearing in the circuit board industry. However, for semi-finished boards after wave soldering, there is currently no complete control requirement for ion pollution in the industry. The researcher conducted experimental verification by optimizing the wave soldering process parameters and the placement time of semi-finished products, and used ion chromatography to test and evaluate. The experimental results showed that the material characteristics of wave soldering flux and the amount of flux sprayed on the printed circuit board surface The degree of contamination will have a great impact, and the spray process parameters are not a key factor. Provide direction for the subsequent reduction of the impact of ion cleanliness on printed circuit board assembly (PCBA).

With the increasing attention of the world to environmental problems, R22 refrigerant products in heat pump industry have been gradually reduced in use, and mainstream refrigerants such as R134a and R410A have been included in the scope of controlled substances. The use of lower GWP refrigerants has become an important support for the sustainable development of heat pump industry. Respectively analyze the application of low GWP refrigerants in three main subdivisions of heat pump industry, high temperature heat pump, ordinary heat pump and low temperature heating; and the possible refrigerant replacement situation in the medium and long term is proposed. At the same time, two typical refrigerants, R290 and CO₂, which are suitable for heat pump industry are discussed, and their future development trend is analyzed. The development of new heat pump products with low GWP refrigerants (including natural refrigerants) which are suitable for China's national conditions and have advantages in international competition will be the follow-up development direction of the industry.

Washing care labels of 294 sweaters from 16 brands was been investigated in physical and online shops. The following conclusions were drawn: (1) Fiber composition: cotton and acrylic fiber are most widely used in all kinds of sweaters. Men sweaters have a relatively high wool fiber percentage. Women sweaters use more chemical fiber such as acrylic fiber, which is easy to improve its color diversity and stability. Children's sweaters add acrylic fiber to increase its color diversity, and nylon is added to improve the friction resistance of sweater. The fiber of baby sweaters mainly is cotton, account for almost 80%. (2) Washing method: In general, 77% of sweaters need to be washed by hand, and a few of sweater can be washing by machine or dry-cleaning. Only 10% of sweaters can be bleached by oxygen, the sweaters of children and baby are nearly 100% non-bleaching. (3) Drying method: Only 2% of sweaters can be bleachable by tumble dryer, 98% of sweaters need to dry under natural conditions. Most adult sweater is recommended to be flattened drying or flattened drying in the shade, account for nearly 85%. For children's sweaters, the proportion of hanged drying and flattened drying are about equal. The baby sweaters are dried in three ways, including hanging, flattening, and dripping, separately accounting for 33.3%, 50% and 16.7%. (4) Ironing method: 82% of sweaters can be ironed at medium or low temperatures, but more than 50% of sweaters need to be ironed at low temperature.

Outdoor sportswear needs to be functional and comfortable. It also has requirements for professional fabric type and style design. It needs to meet specific washing conditions, otherwise it will cause functional damage. Washing label is an important way for household appliances enterprises, detergent enterprises and consumers to understand the demand of caring outdoor sportswear, but the recognition and attention are insufficient by now. This paper investigated 432 durability labels of outdoor sportswear from 10 high proportion brands, and analyzed the information of caring labels such as fiber composition, washing, drying, bleaching and ironing. It was found that: (1) polyester, nylon and cotton are three most commonly used fibers in outdoor sportswear, and storm wear occupies an important position in the market; (2) the wash program of 76.2% of outdoor sportswear is ‘washed by machine, the highest temperature is 30℃, routine or moderate’ 97.9% of outdoor sportswear cannot be dry cleaned and 97% cannot be bleached; (3) 46.5% of outdoor sportswear can be dried in rotary drums; 28.3% can be natural air-dried and the approach is hanging or hanging in the shade; (4) 41.5% of outdoor sportswear cannot be ironed. The research results will help household appliances enterprises, detergent enterprises and consumers to fully understand the requirements of outdoor sportswear caring, design and use reasonable cleaning products.

The production of home appliances requires processing of sheet metal parts. Traditional spot welding and riveting, as non-detachable connection methods, have some limitations in terms of economy and technology. TOX connection technology, as an efficient and environmentally friendly connection method, is increasingly used in the connection of metal appearance parts in the home appliance industry. According to the structural characteristics of the sheet metal parts of the rear panel of the cabinet air conditioner, the specific implementation process of the TOX multipoint connection technology is explained, it has a positive effect on guiding the process of applying the TOX multipoint connection technology to the rear panel components of the cabinet air conditioner and improving the quality of sheet metal parts.

For the low-frequency noise in the washing mode, it is found that its peak value appears with the peak value of the working temperature fluctuation. The relationship between the fixed frequency and temperature of its parts is researched and analyzed, and the LMS software is used for modal and ODS tests, and then ANSYS 15.0. The simulation software found that the 100 Hz solid frequency mode diagram of the inner tank vibrated strongly and resonated with twice the power frequency. According to the analysis results, the specific structure was optimized and the noise at the resonance point of the dishwasher was reduced by 13 dB.

In order to solve the test data transmission problem in the home appliance testing room, the scheme of remote monitoring of home appliance test parameters is designed. In this design, the test data of the EUT is collected by the wireless module and reported to the cloud via the NB-IoT network. Users can monitor the test data and running status of EUT through the web interface anytime, anywhere. NB-IoT network has the characteristics of wide coverage, low power consumption, low cost, large connection, low data rate, etc., which is very suitable for laboratories with strong shielding, good sealing and inconvenient network routing. The application data processing service in the cloud is provided by Zen Cloud IoT Platform, an industrial public cloud service platform in the field of smart appliances. The designed scheme has been verified by actual application and can realize the function set previously.

The disassembly efficiency and accuracy of mobile phone screws directly affect the utilization degree and economic value of the subsequent disassembly and recycling of used mobile phones. In order to improve the efficiency and accuracy of screw disassembly, a device for automatic disassembly of used mobile phone screws is proposed. Aiming at the process of screw disassembly, the overall mechanical structure plan and control system plan of the disassembly equipment are designed. A three-axis rectangular coordinate robot is selected as the mechanical execution mechanism of the screw disassembly module. The electric installation fixture is designed and approved. The specifications were selected, the electric gripper was selected as the actuator of the mobile phone clamping module, the CCD camera and industrial light source were selected as the hardware components of the visual imaging system, and the entire disassembly equipment was built using the motion control card and IO expansion module Of the motion control system, the entire disassembly equipment has a high degree of automation, which can achieve an efficient and reliable disassembly effect.

The light artificial accelerated aging test method commonly used in the home appliance industry is utilized to carry out light aging research on the white ABS material which commonly used in air conditioner panel. On the one hand, the light aging resistance of the color masterbatch material and the modified material are compared; on the other hand, the severity of the commonly used light aging test method was compared. The results show that the light aging resistance of the modified material is better than that of the color masterbatch material. when Xenon-arc lamp aging (x), Fluorescent aging UVA (ZA) and Fluorescent lamp aging UVB (ZB) are used, the response degree of the experimental samples to light aging is as follows: UVB (ZB) test > UVA (ZA) test > xenon lamp (x) test.

Leakage current is one of the main indicators for assessing the safety performance of household appliances, and an important parameter for evaluating the insulation performance of household appliances. To measure the touch current of home appliances, we must first correctly understand and master the concept and measurement method of "touch current" in the home appliance standard. At the same time, we must also master the relevant basic standards, reference standards and IECEE OD guidance document requirements, and clarify the weighted touch current. Related requirements for test equipment. Discusses the touch current from several aspects such as standard requirements, test equipment, and test methods, analyze the trend of standard development.