The low-pressure vapor of the refrigerant in the refrigeration system is sucked by the compressor, compressed into high-pressure vapor, and discharged into the condenser, and the indoor air is continuously circulated to cool down.
Simply put, it is the same as the familiar principle of household air conditioning refrigeration. They are all based on the principle that the rapid expansion of the instantaneous volume released by R 12 or R 134a will absorb a lot of heat energy for refrigeration (at present, R 134a is mostly used in automobile air conditioners).
Automobile air conditioning is divided into four parts, namely condenser, evaporator, compressor and throttle expansion valve.
Understand the principle of air conditioning refrigeration and some main components, and then analyze the common fault points of air conditioning refrigeration at idle speed, but when driving.
1. The refrigerant in the air-conditioning system completely leaks, resulting in no refrigerant, so the air conditioner does not cool.
Solution: You can check some components in the air conditioning system, such as pipelines, air conditioning pumps, condensers, evaporation boxes, etc. Damage and cause refrigerant leakage. There is also an inspection method, which can add fluorescent agent at the same time as refrigerant. After the vehicle has been used for one week, check the air conditioning system with a special fluorescent lamp. If there is a leak, it will light up, indicating that this part is damaged.
2. The air-conditioning pump is damaged internally, such as the piston ring and clutch sucker inside the air-conditioning pump. As a result, the air conditioning pump cannot work and the refrigeration effect cannot be started. Generally, abnormal sound will appear when the air conditioning pump is damaged.
Solution: Check the air conditioning pump. If it is damaged, it needs to be replaced.
3. The condenser radiator in the air conditioning system is too dirty, which leads to the high pressure and temperature of the air conditioning system. In order to protect the air conditioning system, the air conditioning water pump stops working, so the air conditioner does not cool. When driving, the air conditioning system can be cooled by the vehicle speed, so the air conditioning system will be cooled when the vehicle is driving.
Solution: You can use a high-pressure water gun to clean the radiator of the lower condenser. After cleaning, blow dry with a high-pressure air gun.
Understand the wage principle of air conditioning heating. According to the types of heat sources, automobile heating systems are mainly divided into two types: one is to use engine coolant as the heat source (currently used by most vehicles), and the other is to use fuel as the heat source (used by a few middle and high-class vehicles). When the engine coolant temperature is high, the coolant flows through the heat exchanger in the heating system (generally referred to as the small heater tank), and the air sent by the blower exchanges heat with the engine coolant. After being heated, the air is sent into the car by the blower through various air outlets.
The heat source we know is the principle of heating by using the heat of coolant, so we should first check whether the coolant is enough. If there is a lack of coolant, the heating effect of the air conditioner will be poor.
You also need to check whether the cooling fan is working properly. If the cooling fan rotates frequently, the water temperature cannot rise, and the heating effect of the air conditioner will become worse.
The blockage or leakage of the warm air tank will also lead to poor heating effect or even no heating.
The above points are the most common fault points of poor air conditioning heating.
Therefore, it is necessary to change the coolant regularly. If the coolant is not replaced for a long time, it will lead to the deterioration of the coolant, the cooling effect will be reduced, the heater box will be blocked, and the heating effect of the air conditioner will be poor. The replacement cycle of coolant is generally about 2 years and 6 kilometers.