The three heating methods used by the air conditioning heater of new energy vehicles can be divided into wind heating, water heating and heat pump according to the heating medium and heating method.
1. Air heating mode (heating element is resistance wire or PTC) : electric heating components are arranged in the air outlet channel of air conditioning, and air directly flows through the heating components to be heated and blown into the car cabin.
2. Water heating (the heating element is PTC or thick film heating) : the heating element is arranged in the liquid flow passage of the component, and the heat is brought to the heat exchanger in the outlet passage by circulating the heating liquid, and the air is heated directly through the heat exchanger and then blown into the cabin of the car.
3 heat pump mode: although the energy efficiency ratio is the highest, but in some areas when the ambient temperature is low in winter, heating can not guarantee the normal use of vehicles, so it has not been applied in domestic passenger cars.
The wind heating mode has the characteristics of simple system and easy layout. Due to the high temperature of the air heat exchange interface, the heating comfort of the occupants is not strong. In addition, the electric heating parts into the cabin of the passenger car, there is a big security risk.
Water heating method can effectively improve occupant heating comfort, electric heating components in the front cabin, higher safety and reliability, but the component manufacturing technology is difficult. From the perspective of safety, water heating is the mainstream of the future development of new energy vehicles.
Classification and characteristics of new energy vehicle water heater: from the heating elements used, water heater can be divided into PTC and HIC two technical routes, and both types of products have mature applications in listed new energy vehicle models. PTC water heating heater to Germany Eberge as the representative, HIC thick film heating to Germany Weibast as the representative.
HIC thick film water heating heater because of its simple structure, less heat exchange interface, so that it has the characteristics of high heat exchange efficiency, small volume, light weight, has the advantages of stable resistance, power no attenuation, low heat capacity and thermal resistance, its good controllability and no starting current impact electrical performance than PTC heating advantages. The reason why the heat transfer efficiency of HIC thick film heater is higher than that of PTC heater can be explained by the second law of thermodynamics (principle of entropy increase). Because the entropy of an isolated system never decreases automatically, but increases in an irreversible process. In the heat transfer environment of water heating heater, the heat transfer process conforms to the irreversible process described in the second theorem of thermodynamics, so the heat transfer efficiency mainly depends on the heat transfer temperature difference between high and low temperature in the heat transfer process. When the fluid temperature is heated to the operating temperature (60-90℃), the operating temperature of the core heating element of the PTC heater is about 250℃, while the operating temperature of the core heating element of the HIC thick film heater is about 200℃. Therefore, the HIC thick film has lower exchange temperature difference than PTC, so it has higher heating (heat transfer) efficiency (that is, less entropy increase).
The main characteristics of thick film products:
1. Fast temperature rise (80~150℃/s);
2. High thermal efficiency (≥97%);
3. Long service life (≥10000 hours);
4. High power density (40-100 w/cm²), small size;
5. Multiple insulation and safety protection.
Xinxiang Jeda company is the design, production and sales of thick film heating suppliers, can be customized according to customer requirements of any size and parameters of the product, welcome to consult ~~~~