In this article, we briefly describe the application of PTC heaters for electric vehicles. As a professional manufacturer of PTC heaters and air-energy auxiliary heaters, Yixing Xingchen Electric Heater Co., Ltd. will try our best to organize and publish various related knowledge. Sincerely at your service.
Electric vehicles have a long history, and their existence time is no shorter than that of internal combustion engine vehicles. Early electric vehicles were restricted by storage batteries and other factors, so the air conditioning system was designed to not consume electrical energy during use. One method is to provide heating for the vehicle interior while charging the battery. This method is only suitable for short-distance driving. That is, at the beginning of the operation of the electric vehicle, a comfortable temperature can be maintained in the interior of the vehicle. As the operating time increases, the performance of the air-conditioning system drops rapidly. Another method is to use an independent small fuel device to increase the ambient temperature in the electric vehicle compartment. Although this method can better meet the heating requirements of the vehicle compartment, the combustion products will still pollute the environment. With the continuous advancement of science and technology, there are more and more indoor heating methods for electric vehicles, such as the use of PTC heaters, air-conditioned seats, heat pump air-conditioning systems and other methods. 1. Use PTC heaters for heating PTC generally refers to semiconductor materials or components with a large positive temperature coefficient, and usually refers to a positive temperature coefficient thermistor. When the temperature of the PTC thermistor exceeds the Curie temperature, its resistance value will increase sharply, so that the power of the heater becomes very small. At present, when the ambient temperature is low, most electric vehicles use heaters made of PTC thermistors to increase the ambient temperature in the vehicle interior. When the heater made of PTC thermistor is used to heat the interior of an electric vehicle, although it has the advantages of constant temperature heating, no open flame, fast temperature rise, low cost, long service life, green environmental protection, and no need for control systems, it does not The housing of the heater assembly needs to be modified, but the energy consumption is high. When the vehicle interior needs to meet the requirements of relevant regulations such as defrosting and heating, the PTC needs to reach a power of more than 3kW. This will not only have a greater impact on the battery, but also produce peculiar smells, posing safety hazards. Since the PTC heater is a heating device that directly converts electrical energy into heat, its maximum energy efficiency ratio is only 1. For electric vehicles, PTC heaters are not an ideal heating solution. 2. Using the residual heat of the motor coolant, and at the same time assisting the PTC heater to heat the electric car. During the driving process, the driving motor needs to be cooled. Therefore, the heating method similar to the traditional internal combustion engine car can be used, that is, the residual heat of the motor coolant can be used to increase The ambient temperature in the vehicle compartment. When the residual heat of the coolant cannot meet the heating requirements of the vehicle interior, PTC heaters are used for heating at this time. It can be seen that when using this method to heat the interior of an electric vehicle, when the PTC heater is not working, almost no electricity is consumed, but some pipes, valves, heaters and other components need to be added, and at the same time, it is necessary to The control system was redesigned. 3. Air-conditioned seats are used for heating. When direct current passes through a closed circuit composed of different conductors, in addition to generating irreversible Joule heat, there will also be heat absorption or heat release at the joints of different conductors. This phenomenon is called Peltier effect. The thermoelectric air-conditioning system made according to the Peltier effect can realize heating or cooling of a specific area by controlling the current. If the thermoelectric air-conditioning system is arranged inside the seat through a certain method, it constitutes an air-conditioned seat system. 4. Heat pump air conditioning system for heating Heat pump is an energy-saving device that uses a small amount of high-grade energy to make heat flow from a low-temperature heat source to a high-temperature heat source. The same set of equipment can achieve cooling and heating functions. If the heat pump air-conditioning system is used to increase the indoor temperature of an electric vehicle, it can meet the heating requirements with less energy. The heat pump air-conditioning system suitable for the indoor environment adjustment of electric vehicles can be directly modified on the air-conditioning system of the original vehicle. When the heat pump air conditioning system is working in the cooling mode, the high temperature and high pressure superheated working fluid discharged from the compressor first enters the outdoor heat exchanger (condenser in the cooling mode) through the four-way reversing valve, and the working fluid is in the condenser The carried heat is dissipated to the environment outside the car and becomes a supercooled liquid with medium temperature and high pressure. Then the working fluid flows through the throttling mechanism, becomes a low-temperature and low-pressure gas-liquid mixture, and then enters the vehicle interior heat exchanger (the evaporator in the cooling mode). The working fluid evaporates and absorbs heat in the evaporator to become a low-temperature and low-pressure gaseous state, thereby bringing the heat in the vehicle interior to the heat pump air conditioning system. At the same time, it also reduces the ambient temperature in the vehicle interior and realizes the cooling function. Finally, under the suction of the compressor, the working fluid returns to the compressor through the four-way reversing valve. Under the action of the compressor, it becomes a high-temperature and high-pressure gaseous working medium to complete a cycle. When the heat pump air conditioning system is working in heating mode, under the suction and compression of the compressor, the low-temperature and low-pressure gaseous working fluid in the outdoor heat exchanger (evaporator in heating mode) is commutated by four-way The valve enters the compressor, and the superheated gas that becomes high temperature and high pressure after compression enters the heat exchanger (condenser in heating mode) through the other passage of the four-way reversing valve. The working fluid transfers the heat carried in the condenser to the vehicle interior, thereby increasing the ambient temperature in the vehicle interior. At the same time, the working fluid becomes a medium-temperature and high-pressure supercooled liquid. After the working fluid discharged from the condenser passes through the throttling mechanism, its temperature and pressure are further reduced, and become a low-temperature and low-pressure gas-liquid mixed state, and then enter the evaporator to evaporate and absorb heat, thereby bringing the heat in the environment into the heat pump air conditioning system . From the law of conservation of energy, the heat pump air conditioning system working under the heating model, the heat obtained in the vehicle interior is the sum of the heat energy absorbed by the working fluid from the vehicle exterior and the power consumption of the compressor, so the energy efficiency of the system is relatively high. By comparing the heating methods of electric vehicles in winter, it can be seen that the use of heat pump air conditioning systems to increase the temperature of the vehicle interior has obvious advantages. This is mainly because the heat pump air-conditioning system has a high energy efficiency ratio. It can meet the heating/cooling requirements with relatively little electric energy under the same cooling/heating load in the car interior, and a set of equipment can realize the dual functions of cooling and heating. . In addition, the heat pump air-conditioning system can be modified on the basis of the original air-conditioning system, with fewer changes to the entire vehicle.
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The company is a high-tech enterprise specializing in the research, development and production of PTC ceramic materials and PTC heater components, with an annual production capacity of 1.5 million sets. With a dedicated and professional attitude, we have been continuously researching in the field of PTC materials for many years, and have successively developed products that meet the needs of the market. We continue to improve technology and facilities, and now we have formed a complete PTC heater production line with sufficient testing capabilities. In recent years, we have been committed to promoting the application of PTC products in air conditioners and electric heating appliances. Through reasonable selection of materials, we designed PTC heaters with surface insulation and low thermal resistance radiating strips. Ensure the electrical performance of the product and improve the reliability of safe operation. Products are also widely used in train air conditioning heating, wind turbine cabin heating, air curtain heating, medical system heating, mosquito repellent heating, and water heating.
In addition, the company also processes special-shaped sheet metal parts and cuts and folds various sheets. It specializes in processing and manufacturing various precision chassis, cabinets and other sheet metal products. Now it has large-scale laser cutting machines, CNC shears, and folding machines. , Punches and automatic welding machines and other processing equipment.