Aiming at the characteristics of wide frequency range and variable use environment of household inverter air conditioners, several commonly used frequency control techniques are studied. Simultaneously, a simulation system is constructed to simulate and compare the control effects under different deviations. The simulation results show that the fuzzy-PID control has advantages in response speed, overshoot, stability, control accuracy, and has broad application prospects in inverter air conditioner frequency control.

In order to protect the memory files and objects, special requirements are put forward for the temperature, atmospheric humidity and air cleanliness of the internal environment. The idea of independent control of temperature and atmospheric humidity and remote control technology are using to build a multi-source thermostatic cycle system with temperature and atmospheric humidity cascade adjustment. The collected parameters such as temperature, humidity and air dust content are converted into wireless network signals through the wireless network converter. It is then transmitted to the central control system. Finally, the scientific management and energy consumption optimization of the environment of archival repository are realized. The energy saving rate of the core technology of environmental monitoring and adjustment system of archival repository is up to 20%. The related technology can also be applied to agricultural dryer, thermostatic swimming pool, tall building air-conditioning system and refrigeration equipment performance research and test laboratory.

As the growing development arising in rural-to-urban shift, the application of refrigeration equipment is getting more and more widely. And the electric control of refrigeration equipment is becoming under the industry spotlight. On the base of that, this essay concerns on the control manner in refrigeration equipment, discusses elaborately energy-saving method used in electric control of refrigeration equipment. I hope it will take some enlightenment for relevant specialists.

The traditional washing machine uses mechanical switch to control the imbalance of dehydration. The cost of this technical scheme is low, but the uncertainty of dehydration trajectory is prone to failure. In this paper, an acceleration sensor is proposed to detect the vibration amount of dehydration. According to the vibration amount, the dehydration mode and the maximum speed of dehydration are selected to ensure the safety and stability of the dehydration process.

This paper provides a way to feedback the position of the air deflector through the hardware detection circuit, correct the sweep angle by the program software, and realize the closed-loop control of the sweep angle. When the wind deflector is out of the set angle due to the accidental touch, the program can be passed. Control automatically corrects the sweep angle to enhance the comfort of the mobile unit.

This paper discussed some topics of the high frequency start of the compressor, based on the variable frequency air conditioner which uses high frequency startup compressor. with the Simulink simulation analysis and actual test results, to optimize the PID parameters and determine the compressor high frequency starting drive control parameters. With the test verification and analysis, the frequency adaptive control factors after the compressor high frequency start are given, and the characteristics of the cooling medium flow demand in this stage are pointed out, and the expansion control scheme of the expansion valve is determined. This paper summarizes the reasonable and reliable design scheme of the compressor high frequency starting. It can ensure the long-term operation of the unit while achieving the effect of fast cooling and heating of the air conditioner.

Reverse cycle defrost mode for defrosting by heating transformation for the cooling mode, when the compressor stop, four-way valve reversing, frost during the evaporator absorbs a lot of calories to defrost, cause indoor temperature fluctuation and the temperature drop is larger, less comfortable experience. Also exist in the process of defrosting larger compression, low evaporation temperature, frequent compressor start cause oil level lower reliability problems. This paper presents a new intelligent frost model that hot gas defrosting, defrosting period remains heating mode. Electronic expansion valve fully open, in order to realize the system within the throttling element "slight throttling", the effect of using the compressor discharge of high temperature gaseous refrigerant in the evaporator to condenser defrosting. Without any increase in production costs, on the basis of realization of defrost during continuous heating, improve heating comfort and reliability.

This paper introduces in detail the circuit principle, data sampling and processing methods and implementation steps of air-conditioning delay protection technology, the process of establishing and calculating table-looking data, and the methods of improving timing accuracy. It overcomes the key technology that the indoor unit cannot get the power-off time when the outdoor unit power-off time exceeds the given value, so that when the outdoor unit power-off time exceeds the given value, it immediately provides 220V AC for the outdoor unit and starts the work of the air conditioner; when the outdoor unit power-off time is lower than the given value, it only needs to wait for a certain time. After subtracting the time value of power off from the given value, the power supply is provided for the outdoor unit, which can make the outdoor unit run normally as soon as possible and shorten the possible waiting time for power supply. It not only protects the pressure balance of the system, but also plays the role of rapid refrigeration and heating.

Adjust the defrosting process of Frost-Free Refrigerator from continuous heating of the heating tube to intermittent heating through the program control, so that the residual temperature of the heating tube can be effectively utilized to control the temperature of the evaporator silos so as to completely remove the frosting in the evaporator. In addition, this can reduce the potential safety hazards caused by the excessive temperature in the evaporator silos and meanwhile save energy and reduce consumption.

In the water temperature constant temperature control of gas water heaters, there is output temperature fluctuation or overshoot, and the control is not ideal. This paper proposes a composite controller based on reality: expert PID controller. Through the theoretical analysis and mathematical modeling of the gas water heater, the first-order inertial system with hysteresis is obtained. Expert intelligent control is a kind of control algorithm combining practical control experience and theory. By extracting the characteristics of control objects, learning and reasoning, etc., a better control algorithm is obtained, which is combined with PID to obtain a composite control. The composite controller can eliminate or weaken the hysteresis to achieve a fast and stable temperature. The control algorithm and the control object model are simulated in Python, which saves the time for experimenting on the real machine and speeds up the tuning of the algorithm.

This paper analyses the structure, control method and key points of safety structure design of bare-element instantaneous water heater, and puts forward the corresponding safety structure measures according to the requirements of Standard GB 4706.11-2008 (Household and similar electrical appliances-Safety-Particular requirements for instantaneous water heaters) and "Technical resolution document on CCC certification requirements for bare-element water Heaters" (Document 2012-TC04-3).

With the continuous development of electric water heater, personalized customization has gradually become the mainstream. In terms of appearance, more and more users are beginning to pursue differentiated shapes and colors. As a result, the electric water heater industry has also set off a change from the appearance of a single "big white bucket" produced by cold board powder to an iterative upgrade of colorful board products. The use of color plates with higher color differences as the material for making the shell of the water heater will give the water heater a more distinctive personalized difference. Under such demands, thin-walled panel welding has become an urgent problem.

With the increasingly tense situation of energy and environment, the use of new energy sources such as renewable energy is becoming more and more important. Solar energy is most widely used for its rich and clean features. This paper combines solar energy with a traditional heat pump system to explore the performance of solar heat pump water heaters at low temperatures. Research shows that the solar heat pump system can improve and expand the low temperature application range of the pure heat pump system, and the stronger the solar radiation, the better the system performance; the low temperature defrosting method should adopt naturalized frost to avoid the high energy consumption and easy of the forced defrosting the disadvantage of liquid hammer and reduced system performance.

The problem of internal fouling of washing machine has been concerned by the majority of users, but the current treatment methods of fouling are not satisfactory. This paper analyzes the formation mechanism of fouling in washing machines and compares the existing methods of washing machines to treat fouling. It is proposed that tap water should be sprayed into the interlayer of the washing barrel at a specific time during the last dehydration process of the washing machine to wash and remove the rinsing water attached to the barrel wall. By removing the source of pollution, the fouling of the machine is prevented, and the laundry barrel is kept clean. It provides a new way to solve the scaling problem of automatic washing machine.

The scale problem is an important issue related to the safety of electric water heater. In this paper, the mechanism of the water scale of the electric water heater was analyzed. At the same time, four solutions from different angles of prevention, slowing-down, monitoring and removal, to reduce or eliminate the problem of the scale of the electric water heater were also introduced.

The deformation of the refrigerator door has always been a hot topic in the research of various refrigerator manufacturers. The structure of the refrigerator door is diverse and complex. The deformation of the refrigerator is not effectively solved under the constraints of material selection and production cost. In view of the refrigerator door body and its key components, a structural optimization design method based on multi field strength analysis model is proposed in this paper. Firstly, based on the experiment and simulation data of the refrigerator door, the basic strategy of the door strength optimization is put forward. Secondly, the structure characteristics of the key parts - the door trim bar are analyzed. The frame stiffness model is constructed based on the section structure characteristics of the refrigerator door trim section. At the same time, the maximum bending section coefficient of the section of the door trim section is analyzed, and the section coefficient analysis model is constructed. Based on the model, the optimal size distribution of the door trim section is analyzed, so as to optimize the structure of the door trim and enhance the deformation resistance of the door trim. Finally, through a certain type of door model and simulation analysis, the feasibility and effectiveness of the proposed analytical model and optimization design method are verified.

As one of the key indexes to measure the energy efficiency of water heaters, thermal insulation performance directly affects the use and promotion of water heaters. With more and more high requirements for energy saving and environmental protection ideas, the thermal insulation performance of water heater tank is paid more and more attention to by production enterprises. Through experimental verification and theoretical analysis, this paper systematically studied the influence law of foaming raw material ratio and foaming layer density on the insulation performance of the water tank. The results showed that when the ratio of isocyanate and combined polyether polyol was 1.05:1, the foam layer density was 38~45Kg/m³, the insulation performance of the water tank was better, and the temperature drop of the water tank could be reduced.

This paper summarizes the research on heating power of defrosting heater in air-cooled refrigerators by Chinese scholars, and puts forward a theory that the input voltage of defrosting heater is stabilized to a certain constant value by setting a voltage stabilized power supply on the control board and chopping off the voltage waveform, thus realizing the constant power output of defrosting heater. Two prototypes were fabricated and the power voltage gradient was tested. The results show that the power fluctuation rate of the defrosting heater is stable in the range of ±5% of the target power, and the constant power output of the defrosting heater is realized.

Traditional reverse osmosis (RO) water purifiers generally consist of five step filter units, which have many series of filter elements, occupy space, different life and inconvenient replacement. In addition, filter bottles, water valves, pressure switches and other water-related components are basically connected through water pipes, with many leakage points, inconvenient production and maintenance, and high cost. The shortcomings of the traditional water purifier, it is necessary to introduce a new integrated design of filter element and waterway plate. Through the new integrated design of water purifier, the performance and reliability of water purifier are further improved, user feel is better, and product upgrade is promoted.

With the rapid development of science and technology, the speed of renewal and replacement of electrical and electronic products has also increased, resulting in a large amount of electrical and electronic waste, and bringing to resources waste and environmental pollution. However, under the current system of fund collection and piloting the Extended Producer Responsibility, there are still many problems in the recycling of electrical and electronic waste. By adopting the case analysis method, this paper separately analyzed two successful cases: one is the pilot of Extended Producer Responsibility in China, namely Changhong in Sichuan Province, and another is the Korea, a country who implemented the Extended Producer Responsibility. From these analyses, we want to explore the improvement of electrical waste recycle system of China based on Extended Producer Responsibility, and provide certain feasible suggestions.

In order to better evaluate the noise of food processer,the sound quality evaluation method was used to study and analyze the noise of different functions in the food processer. The results show that noise quality was influenced by the speed of motor, material of cup, base stability and working procedures. The research has a significant guiding for the acoustic design and noise quality improvement of food processer.

We mainly studies the influence of the heat transfer performance of the tooth profile of internal thread copper tube in heat exchanger ‘s refrigerant side. The spiral angle is usually in the range of 10°to 30°the effect of spiral angle on the performance of heat exchanger was studied by increasing the spiral angle of spiral angle and the lager number of gear tooth. The trend of increasing the helix angle and gear tooth to the heat exchanger performance was analyzed by monomer test and the whole machine performance test. It lays a good the oretical foundation for thes further development of efficient copper tube.