In the Automotive OEM factory wiring harness engineers work friends, I believe inevitably going to find the cause of the malfunction problem of Automobile air-conditioning failure, mainly introduce today constitute the working principle of Automotive air-conditioning refrigeration and heating systems.
configuration and operation principle of a refrigeration system
, an Automobile air conditioning systems
FIG as air conditioning compressor, a condenser, reservoir (now Cars are basically integrally and condenser), an evaporator, air conditioning pipes, expansion valve. With the development of Automotive air-conditioning technology, Is now an evaporator, an expansion valve integrated in the air conditioner are substantially the HVAC, HVAC addition to these two integrated blower, heater and air-conditioning equipment systems various types of sensors and actuators.
Working adjusting the refrigeration system refrigerant gasification and liquefaction processes constantly to the compressor and an expansion valve for the community center, the whole refrigeration cycle can be divided for the high and low pressure two portions, the details may be learned by FIG. In the refrigerant cycle system can be divided into four working process Is as follows:
1 compression. Temperature low-pressure refrigerant gas after evaporation processing, through the compressor suction and compressed into high temperature high pressure gas, and then input to the condenser.
2. The condensation heat. Temperature high-pressure refrigerant gas enters the condenser, due to the reduction of pressure and temperature, the refrigerant gas Is condensed to a liquid and evolution of considerable heat to the outside atmosphere.
3. Throttling. Temperature and higher pressure refrigerant liquid through an expansion device after the larger volume, a sharp decline in pressure and temperature, a mIst (fine droplets) dIscharging the expansion valve. ThIs refrigerant Is a high-pressure line, a throttle valve of the expansion effect.
4 and evaporated. MIst-like liquid refrigerant enters the evaporator, and therefore much lower than the boiling point of the refrigerant within the evaporator temperature, it Is evaporated into gas refrigerant liquid. It absorbs surrounding heat in the evaporation process, and then temperature low-pressure refrigerant vapor and enters the compressor.
The above process cycle Is to proceed, the evaporator can be to reduce the circumferentialAir temperature surrounding object. At the same time, the cold air drawn into the blower vehicle, and the dIscharged hot air inside the vehicle, so that the interior temperature Is lowered, the cooling effect Is achieved.
Second, the air-conditioning heating system structure and working principle
Now the waste heat of the cooling liquid after the main Auto sufficiently by the cooling of the engine Is warming thIs way also commonly known as water-cooled. When a higher heating performance requirements, usually associated auxiliary PTC heater Is heated, and ultimately achieving a good effect of heating. The heating system for the air conditioning heat exchanger main components, mainly used for heating of the vehicle interior from the outside air or fresh air into the vehicle interior Is heated, heating to achieve the purpose of dehumidification.
As shown above, the engine cooling water to bypass the control valve out of the way of the cooling water into the heater core fan heater heat exchange, put cooling water heat refluxing outlet pipe through a heater to the engine; the same time, cool air sucked by the blower to a heater core Is heated, blown into the vehicle interior via a different outlet, for heating and windshield defrosting. By controlling the opening and closing of the cooling water flow amount and size of the control valve can be adjusted for the heat convection heater.