What is the function of a car air conditioner's evaporator?

[LeDaniella]

The function of the evaporator is to evaporate the low-temperature refrigerant coming from the expansion valve under low pressure, converting it into vapor and absorbing heat from the cooled medium, thereby achieving the purpose of refrigeration. Daily maintenance for it is as follows: Regularly perform leak detection on the evaporator: When an ammonia evaporator leaks, there is a pungent odor, and frost does not form at the leak point. The leak can be checked using phenolphthalein test paper because ammonia is alkaline and turns the test paper red. Visually, the area where frost does not form on the evaporator is usually the leak point, or soapy water can be used to locate the leak. Regularly check the frost condition on the evaporator: When the frost layer is too thick, it should be removed promptly. Abnormal frost formation may be due to blockage, and the cause should be identified and addressed immediately. When the evaporator is out of service for a long time: The refrigerant should be transferred to the liquid receiver or condenser, keeping the evaporator's pressure at about 0.05MPa (gauge pressure). If it is an evaporator in a brine tank, it should also be rinsed with tap water, and the tank should be filled with tap water after rinsing.