The secret of pure electric car air conditioner_Yangzhou Jumbo Win Automotive Industry Co.,Ltd.

For pure electric vehicle air conditioners, the power source comes from the electric motor, replacing the traditional belt drive. The motor is generally assembled with the compressor and is coaxially driven to form a fully enclosed structure. When the direct current of the battery pack is supplied to the air conditioner compressor driving motor through the inverter, the air conditioner motor drives the compressor to rotate, thereby forming a refrigeration cycle and generating a cooling effect. The compressor speed is changed by adjusting the motor speed to achieve flexible control of the air conditioner compressor displacement and cooling capacity.

Advantages: simple structure, high reliability and low failure rate. In the choice of compressor type, the pure electric vehicle uses a scroll compressor. Compared with other types (such as swash plate type, crank link type, vane type compressors), the scroll type has small vibration, low noise, long service life, light weight, high rotation speed, high efficiency, small size and so on. The advantages are more in line with the air conditioning requirements of electric vehicles.

Scroll compressor

The scroll compressor is mainly composed of a fixed scroll and an orbiting scroll of the same linear shape, and two mutually engaged scrolls. They are 180° offset from each other (ie, the phase angles differ by 180°). The fixed scroll is fixed on the frame, and the movable scroll is directly driven by the motor, but cannot rotate, and can only revolve around the fixed scroll with a small radius of revolution.

When the driving motor rotates to drive the orbiting scroll to revolve, the refrigerant gas is sucked into the peripheral portion of the fixed scroll through the filter element. As the driving shaft rotates, the movable scroll moves in a trajectory in the fixed scroll, so that the moving and fixed scrolls The six chambers are gradually reduced from the outward to the inner volume, and the refrigerant gas is gradually compressed in the six crescent-shaped compression chamber composed of the movable and fixed scrolls, and finally the compressed air is compressed from the center hole of the fixing plate through the valve plate. The gas is continuously discharged.

During the whole working process of the compressor, all the working chambers are gradually reduced from the outside to the inside and are in different compression conditions, thereby ensuring continuous inhalation, compression and exhaust of the scroll compressor. Although the scroll compressor discharges the refrigerant at a small amount each time, the discharge amount is 27 to 30 cubic centimeters, but since the movable scroll can be rotated up to 9000 to 13000 r/min, its total displacement is sufficient. Large, can meet the needs of vehicle air conditioning refrigeration, of course, the power consumption of the compressor is also large, up to 4 ~ 7KW.

A complete pure electric vehicle air conditioning system mainly includes: compressor, evaporator, condenser, heater core, water tank, intercooler, oil cooler, HVAC pipeline assembly, HVAC housing expansion valve, control unit And other components. Because the refrigeration principle is the same as that of the fuel car air conditioner, we will not repeat them here. Today, just look at the special features of it - the warm air supply of pure electric cars!

There are three types of heaters: heat pump type, PTC electric heater type, residual heat + auxiliary PTC type. Due to space limitations, we only explain the PTC electric heater.

The PTC is a direct-heating resistor material that generates heat when energized and can be used to heat the air conditioner. If there are 8 PTC heating elements inside the electric vehicle air conditioner, the high-voltage power supply of the battery is supplied by the air-conditioning driver to each component, and the power can reach 300-600W for heating the cold air or the cooling liquid. In order to improve the efficiency of the heating device, the current heating takes water as the medium, and the water is heated and sent to the radiator of the air conditioning duct, and then blown into the cabin or the windshield by the fan to increase the temperature inside the cabin and Remove the frost from the windshield.

The temperature and resistance characteristics of the TC component. When the component is energized, its resistance will gradually decrease with increasing temperature, that is, its heat generation at normal temperature is low. When the temperature exceeds the "Curie temperature", the resistance value increases stepwise as the temperature increases. The temperature of the blown gas can reach up to 85 °C, which can fully meet the requirements of air conditioning heating. When the temperature is higher than 85 °C, the PTC resistance becomes extremely large, and the actual performance is automatically stopped.