With the rapid development of the electronic industry, the upgrading speed of electronic products is accelerated. While technology brings convenience to human beings, it also brings more and more electronic waste, which seriously affects the ecological environment. By analyzing dismantling capacity of E-waste and the scale in Guangdong province from 2013 to 2020, this paper has studied the current situation and causes of E-waste disposal in Guangdong province, identify the risks in the process, and present some countermeasures such as government-led enterprises and consumers' participation in disposal, with a view to promoting the integration of production, research and development and the construction of recycling system, etc., and also provides some references for the treatment of E-waste in Guangdong province.

This article takes electronic products as the research object, and studies the management methods of full material disclosure in the field of electronic products through comparative analysis. The article first introduces the development of electronic products to e-waste and the definition of e-waste in the European Union and China. Aiming at the dual attributes of e-waste resources with high value and high environmental risks, it lists relevant laws and regulations on the environmental management of e-waste at home and abroad. Through the research on the management status, it's found that China's implementation of full material disclosure may have problems with multiple responsibilities, management procedures, and technology. Learning from the successful cases of Apple, Lenovo and other fields in the management of full material disclosure, finally put forward the views and suggestions on the management of full material disclosure of electronic products, hoping to provide certain reference for the policy formulation of the management department.

"The overall plan of ecological civilization system reform" puts forward that the important content of accelerating the construction of ecological civilization is "implementing the extended producer responsibility system". By studing reverse logistics related theories and analyzing the current situation of domestic waste household appliances recycling, it is found that although the domestic has built a formal recycling system, the recycling efficiency is low and there are some problems in the reverse logistics system. At present, the "Internet plus" mode is booming in various industries, providing a new way of thinking for improving the efficiency of recycling waste household appliances. Through the design of software system, improve the efficiency of online recycling, reduce the cost of online recycling, realize the rapid docking of online and offline, to provide an efficient management platform for the recycling and disposal of waste household appliances enterprises.

A pretreatment method for the extraction of decabromodiphenyl ether from electronic and electrical products by FOSS Soxtec 8000 automatic Soxhlet extractor has been established. The effects of extraction temperature and extraction time on the extraction efficiency were optimized and evaluated. The results showed that the optimal extraction temperature was 240℃ and the extraction time was 60 min, which was far lower than the traditional Soxhlet extraction time. The quality control samples and blank spiked samples were determined by this method for six times. The relative standard deviation of the determination results was 1.15% and the average recovery was up to 98.2% and 98.8% respectively, which showed excellent extraction efficiency and stability. After each analysis, about 80% toluene can be recovered, and there is no decabromodiphenyl ether detected in the recovered toluene, which can be reused and effectively reduce the use and emission of solvent.

To solve the problems of environmental pollution and resource waste caused by wasted mobile phones, the target disassembly of wasted mobile phones has been studied. Using a directed graph as a disassembly schematic diagram, and formulating a disassembly model, innovatively proposed to use a connection cell array to represent the connection relationship between parts. The ant colony algorithm is used to optimize the target disassembly sequence due to the different lengths. The profit generated per unit time is used as the optimization target, and the optimal or suboptimal disassembly sequence is obtained. Finally, a Huawei P7 mobile phone was used as an example to verify the feasibility of the disassembly model and the ant colony algorithm used in disassembly sequence planning.

The internal structure connection characteristics of used smart phones are the key to study the nondestructive disassembly of used smart phones. Through the dismantling experiments of multiple series of smartphones of three brands of Xiaomi, Huawei and iPhone, a systematic comparative analysis of the internal structure and connection characteristics of the mobile phones was carried out. The advantages and disadvantages and development trends of the structure and connection methods of the three brands of mobile phones were summarized. The structural problems existing in the current dismantling of smart phones and suggestions for improvement are discussed. The overall disassembly of the iPhone is far more difficult than Xiaomi, and Xiaomi is slightly difficult than Huawei. These disassembly experiments provide a powerful support for the trial-manufacture of disassembly equipment for used smartphones and the green design of new smartphones.

Green manufacturing is an important guarantee for the sustainable development of society, and green materials are an indispensable part of green manufacturing. Aiming at the uncertainty and subjectivity of material selection for electric home appliances, a hybrid green material comprehensive selection method called PGT(a hybrid PIV contain GPMBWM and TFMN) is proposed, which includes green evaluation and green-based material selection. PGT includes the method of Proximity Index Value for material selection and the calculation of the weight of the evaluation criteria based on the Goal Programming Model for Best Worse Method, and the use of trapezoidal fuzzy majority to replace the description of qualitative attributes in the construction of the multi-criterion decision-making problem model. Subsequently, the PGT method is applied to the selection of the inner material of rice cookers. The application includes three stages. First, materials are initially evaluated and selected according to the selection criteria of the inner materials, then the green performance of the selected inner materials is evaluated, and finally the liner materials are re-evaluated and re-selected combining the greenness evaluation results. The results showed that the green properties of stainless steel materials is the best.

For the axial fan and motor system of the commercial unit under high speed, abnormal noise were tested and analyzed, the frequency characteristics of the abnormal noise were initially determined; combined with the experimental and simulation analysis method, the structure and the flow field characteristics of the axial fan were analyzed, the main reason of the abnormal noise and it related improvement points were determined; based on these improved points of the flow field, we have completed the related CFD analysis and given the corresponding flow noise improvement methods, which is viewed from the ODS of the axial fan and the interference between the cavity of the flow field and the tip; according to the improved schemes, the improved axial fan and the related experimental verification were completed, the abnormal noise has been significantly improved.

Refrigerator refrigerant noise, as the unique noise of the refrigeration system, is one of the important noise concerns in the user's daily use. By introducing an acoustic camera and establishing an analysis system combining noise and vibration based on acoustic positioning tests, a rapid and accurate analysis is achieved. Refrigerator refrigerant noise positioning test, and the correlation between refrigerant noise and pipeline vibration is clarified through the test data and related mechanism analysis. The refrigerator refrigerant noise is optimized by reducing the capillary tube vibration method, and the theoretical analysis is verified by the experimental verification. It has a good effect and provides a design basis for the optimization of refrigerant noise in the subsequent refrigerator development process.

The mechanism of generating pool boiling noise was analyzed in this paper, it was determined that bubble burst noise was the main noise source of pool boiling noise, by studying the relationship between bubble evolution process and noise. The relationship between the contact angle of the bottom wall and the bubble radius was determined by the force analysis of the bubble from the perspective of bubble dynamics. That was, the bubble radius increased with the increase of the contact angle. The bubble detachment behavior was simulated numerically by VOF method, and the influence of contact angle on bubble size and detachment time was studied. It was found that the maximum sound power decreased with the increase of the contact angle. It was proved that the bubble size could be controlled by adjusting the contact angle and the noise could be suppressed.

The volute tongue of air conditioner is the area with the largest temperature change and the largest temperature difference in a short time when the air conditioner is turned on for heating. When the tongue is heated and expanded, the buckle and other assembly parts will produce deformation displacement, and the parts will produce vibration and sound at the moment of deformation release. In order to solve this problem, the high damping high impact polystyrene (HIPS) material is used to test the noise and vibration amplitude spectrum. The results show that the HIPS material with high damping and low dimensional change rate can greatly reduce the number of abnormal noises and the size of sound caused by thermal expansion.

After the refrigerator closed, due to the door opening of the refrigerator, the inflow of hot air and the decrease of indoor temperature are caused. Negative pressure will be formed in the chamber. As the core part of balancing the pressure inside the box, the drain pipe absorbs air to balance the air pressure inside and outside the box. If there exists water in the evaporating dish, it will generate water absorption noise. By studying the changes of indoor pressure and temperature, the influencing factors of water absorption noise were analyzed. Propose a drainage structure that can balance the negative pressure in the chamber and eliminate water absorption noise. At the same time, reduce the hot and humid air from the drain pipe into the room, improve the power consumption and temperature storage performance.

Base on the characteristic of N.A. unitary air conditioner with non-bleed TXV as throttle valve, raised a fast restart solution for rotary compressor as well as the test validation. Firstly tested and analyzed the pressure change curve after the system is turned off, and then considered the application demand, proposed the technical solution by adding solenoid valve to rotary compressor. Thirdly, designed a new three-way valve by added a resetting spring on one side of the valve core. Lastly, accomplished the validation test of this solution on the unitary system which using a rotary compressor. According to the test result, the resetting design works well and the solution not only has good pressure maintaining function of HEX but also can achieve pressure balance within 3 min which lets compressor properly start up.

At present, storage-type electric water heaters have a large quantity in urban households in our country. Maintenance, component life, and corrosion resistance of the inner tank and heater will affect the service life of the water heater. Corrosion of the inner tank may cause water leakage, electric leakage, and explosion. Such problems endanger the personal and property safety of users. Compares the application of anti-corrosion measures such as heating tube anti-corrosion, magnesium rod anode and electronic anode in water storage electric water heaters, regard electronic anode as future development direction.

With the improvement of people's living standards, users are highly concerned about bathing "healthy water quality" and "noise". At the same time, with the gradual maturity of drinking water treatment technologies such as impurity removal, sterilization, and disinfection, gas water heater companies have launched various selling points of health water heater products, but there are currently no corresponding standards to regulate their health performance in China. Although users know the importance of bathing water, there is no unified standard and quantifiable grade index to help them judge and purchase. Therefore, it is very necessary to establish a reasonable health performance evaluation method and classification standard to regulate the health water heater products on the market. By comprehensively combing, summarizing and categorizing various health technologies in the gas water heater industry, a number of health function indicators have been formulated, and the health functions of water heaters have been divided into 3 levels according to the user's health demand level, technical realization difficulty and investment cost. At the same time, according to the achievement of health function indicators, the health performance of Domestic Gas Instantaneous Water Heater and Gas-fired Heating Hot Water Combi-Boilers is objectively evaluated by dividing the health performance levels. On the one hand, it can ensure the health of users in bathing, and on the other hand, it can guide the development direction of health technology in the industry, which is conducive to the upgrading of products.

Taking 150 W motor as an example, the magnetization principle, magnetization direction, magnetization energy parameter selection, magnetization compensation and magnetization positioning deviation angle are analyzed respectively. Combined with Ansoft simulation, the effects of different magnetization methods, temperature relationship between magnetic steel and rotor outer surface and magnetization positioning deviation angle on air gap flux density and air gap flux are studied. Research shows that improper magnetization direction or insufficient magnetization energy will lead to poor magnetization quality, which will affect the air gap flux, flux density, harmonic content and demagnetization current of the motor, resulting in the motor can not meet the design requirements. Therefore, for different motors, we should choose a reasonable way of magnetization, and improve the quality of magnetization process, in order to make the magnetic steel play the best performance.

The composite films of W/Diamond like carbon (DLC) were prepared on the surface of high speed steel HAP40 by magnetron sputtering. A 5 μm thick composite films (W layer: 1.7 μm; W_XC_Y layer: 0.3 μm; DLC layer: 3 μm) was obtained by adjusting the process parameters. The structure, cross-sectional morphology and friction and wear properties of W/DLC composite films are mainly studied. The results show that the existence of W and W_XC_Y composite layer is benefit to reduce the growth stress of DLC layer and improve its interface bonding. The main wear form of W/DLC composite films is sliding wear which does not adhere aluminum powder, but it would absorb oxygen atom from the air or lubricating oil. There are a lot of hydrogen saturated σ-dangling bonds in W/DLC composite films, which passivates the surface of the composite film and leads to low friction coefficient.

Helium detection is a relatively mature leak detection technology, with ultra-high detection accuracy, and is widely used in the evaporator and condenser of the air conditioning industry. However, limited by helium resources, a low-cost hydrogen-nitrogen mixed gas leak detection technology that can replace helium detection has been applied in a small range in the refrigeration industry. By comparing their respective economic values, describes the overview of the existing hydrogen and nitrogen leak detection equipment, theoretically analyze the relationship between the leakage rates of the two gases, and make leaking test in the vacuum box, integrated analysis the feasibility application, the result is hydrogen and nitrogen detection is feasible in the vacuum box.

Taking one of steam-oven of our company as the research object, taking French fries as the typical frying materials, the research on the improvement of air-frying rate and quality of steam-oven was carried out. By optimization of the product, there was no need to pre-heat or turn-over, and the frying rate was increased by 40%, juicing rate was improved by 12%, and the coloring uniformity of the French fries was significantly improved, which achieved the same effect of the air-fryer. Through further optimization of the cooking mode of air frying, besides high frying rate and good coloring uniformity, the peroxide value of the French fries was significantly reduced by 30% which meant healthier for family. It provided solutions for making delicious, fast and healthy food for the function of air-frying in steam-oven.

Magnetic bearings are often used in high-speed occasions. The limit speed of traditional ball bearings is low, which becomes the key factor restricting its reliability as a backup bearing. Taking the single-decker hybrid ceramic ball bearing as the object, the dynamic process of the high-speed rotor dropping to the backup bearing after the loss of power of the magnetic bearing is analyzed, and the change law of the bearing speed is obtained; then, the speed distribution of the double-decker bearing is studied compared with the single-decker bearing, and the speed improvement is analyzed. Through the performance analysis of the double-decker bearing, it provides a reference for the design of high reliability backup bearing for magnetic bearing system.

Previous studies have indicated that long-term preservation of fruits and vegetables could be achieved by reducing the oxygen content in the environment to effectively inhibit their respiration. Therefore, the researchers of household appliances have been committed to the development of new technologies to reduce the oxygen content in the refrigerator box, prolonging the shelf-life of fruits and vegetables. These technologies include oxygen rich membrane (oxygen-removal), pressure swing adsorption (nitrogen filling), pressure swing adsorption (oxygen-removal), vacuum (oxygen-removal), etc. It is expected to provide reference for the design of refrigerator oxygen control through systematically analyzing the principles, implementation methods and effects of the above technologies, and comparing their advantages and disadvantages at the same time.

To study the preservation effect of oxygen tensions in refrigerators on fruit and vegetable preservation, six kinds of fruits and vegetables (strawberry, blueberry, kiwi berry, spinach, lettuce, cucumber) were stored for twenty days in A1 refrigerator (21% O₂, RH 90%), A2 refrigerator (18% O₂, RH 88%) and A3 refrigerator (15% O₂, RH 86%). The weight loss rate, hardness, soluble solids, vitamin C and polyphenol contents were determined to evaluate the preservation effect of refrigerators. The results showed that the preservation effect of low oxygen (15%, 18% O₂) refrigerator was better than that of high oxygen (21% O₂) refrigerator on these kinds of fruits and vegetables. Lower oxygen tension in the fresh-keeping refrigerator room had better preservation effect on hardness, soluble solids, vitamin C and polyphenol contents of fruits and vegetables, and also significantly slowed down the loss of nutrients in fruits and vegetables. However, the relative humidity of low oxygen refrigerator was low, which resulted in serious water loss in fruits and vegetables with large specific surface area; therefore, humidity would be controlled in the storage of these kinds fruits and vegetables.

At present, most voice air-conditioning products share the same wake-up word wake-up device. Therefore, when multiple voice air-conditioners are wake-up at the same time, there will be a "echo" phenomenon. In order to solve this phenomenon, proposes the key technology research and air-conditioning application of nearby voice wake-up. The front-end voice adaptive noise reduction algorithm is used to solve the indoor environment noise and the internal reverberation of the air conditioner. Then, the master node (master node) and slave node (sub node) are selected by LAN voice distributed networking. Finally, according to the energy value of the sound source or the distance between the sound source and the voice air conditioner, the arbitration decision is made by the master, finally, the air conditioner close to the user's most suitable distance is awakened.

At present, the evaporator used in the air-cooled refrigerator is mainly tube-fin type, in addition to the existing oblique row, inline tube-fin evaporator, in recent years, new tube-fin evaporators have been developed, dilatation, small tube diameter, spiral tube, etc. Analyze the characteristics and advantages of various types of fin-and-tube evaporators through systematic comparison in terms of process, cost, performance (monomer simulation, monomer heat exchange test and whole machine test single unit) and reliability, so as to provide suggestions for the subsequent application of fin-and-tube evaporators in refrigerators.