In fact, the refrigeration principle of automobile air conditioner is the same as that of household air conditioner. Both are based on the principle that the rapid volume expansion of R12 or R134a will absorb a lot of heat energy. The structure of automobile air conditioner is similar to that of household split air conditioner. Its compressor is often installed on the engine and driven by belt (or directly driven). The condenser is installed in front of the radiator of the automobile, while the evaporator is in the car. When working, the low-pressure gaseous refrigerant from the evaporator flows through the compressor and turns into high-pressure and high-temperature gas, After cooling through the condenser radiator tube, it becomes high-pressure and low-temperature liquid, then goes through the desiccator for dehumidification and buffering, then flows to the expansion valve at a relatively stable pressure and flow, and finally flows to the evaporator through throttling and depressurization. The refrigerant evaporates at low pressure and absorbs a lot of heat.
The air in the car continuously flows through the evaporator, so the temperature in the car is reduced. After flowing through the evaporator, the liquid refrigerant turns into low pressure gas again and is sucked into the compressor again for the next cycle. In the whole system, the expansion valve is the mechanism to control the refrigerant into the evaporator, too much refrigerant into the evaporator is not easy to evaporate, and too little cold air will not be enough, so the expansion valve is the regulation center. The compressor is the heart of the system and the power source of the system circulation.
Although the principle of the air conditioning system of automobile air conditioning is the same as other air conditioning systems, automobile air conditioning is a mobile vehicle air conditioning device. Compared with the fixed air conditioning system, it has worse dynamic and rotational conditions. With the chatter of automobile driving, the refrigerant of the air conditioning system is easier to leak than the fixed air conditioning system, and the repair and maintenance of the air conditioning system is also more frequent than the fixed air conditioning system, When the air conditioning system inhales fresh air, it often sucks dust, blocks the filter screen and evaporator, and releases the refrigerant into the atmosphere during the cleaning process. It causes the depletion of the ozone layer and destroys the environment.