The refrigeration principle of an air conditioner
The electric air conditioning compressor extracts the gaseous refrigerant from the evaporator and then presses it into the condenser in the form of a high-pressure gaseous state. When the high-pressure gaseous refrigerant passes through the condenser, the heat is released and turned into a liquid state, and the refrigerant flows through the expansion valve and enters the evaporation box in the form of mist under the action of throttling, and the refrigerant absorbs a large amount of heat in the evaporation tank and evaporates rapidly, turns into a gaseous form of low temperature and low pressure, and is pumped away by the air-conditioning compressor again, and so on. At the same time, the cooled air near the evaporation tank is blown into the carriage through the blower to achieve the purpose of cooling the compartment.
The air conditioner controller is the core component of the whole air conditioning system, and the air conditioning driver receives the information from the air conditioning controller to control the air conditioning compressor and PTC heater.
The air conditioning controller receives information from various sensors and the air conditioning control switch, and after computing and processing, it sends commands to the air conditioning driver and other actuators to adjust the temperature in the vehicle.
The maintenance process of the air conditioning system of new energy electric vehicles is roughly the same as that of traditional fuel vehicles, taking the JAC IEV5 model as an example. When the air conditioning system fails, follow the following process for maintenance.
Air conditioning and refrigeration system maintenance process
1) System pressure measurement: The equilibrium pressure is 0 when the air conditioner is not turned on6MPa, if the line pressure is too high or too low, the compressor will not work, if the pressure is normal, proceed to the next check.
2) Check the high-voltage power supply of the air conditioner, check whether the refrigeration circuit breaker in the high-voltage junction box is fused, and replace the new circuit breaker directly if the circuit breaker is normal, it means that the high-voltage power supply of the air conditioner is normal, and the next step of inspection is required.
3) Check the AC switchWhen the AC switch is pressed, check whether the air conditioner controller receives the start-stop signal of the air conditioner control panel, and use a multimeter to detect the white wire terminal voltage of the 6pin connector of the air conditioner controller, which is 12V when AC is not pressed, and becomes 0V after AC is pressed. If there is no start-stop signal, perform the 4th step check, if there is a start-stop signal, then the 5th step check.
4) Check whether the buttons of the air conditioner panel are normal, whether the power supply and tie iron of the panel are normal, whether the pressure switch and related wiring harness are normal, and whether the temperature sensor of the evaporation tank and related wiring harness are normal.
5) Check the air conditioner compressor to check whether the compressor is damaged, you can use the multimeter resistance gear to measure whether any two phases of the compressor 3pin pin can be turned on, if there is no conduction, it means that the compressor is damaged and needs to be replaced.
6) If all parts are judged to be normal, it means that the air conditioner controller is faulty. The controller assembly needs to be replaced.