PPA manufacturer introduces the principle and method of temperature control of automobile manual air conditioner

1. Composition of automobile air conditioner

Automobile air conditioners are generally composed of compressors, electrically controlled clutches, condensers, evaporators, expansion valves, liquid storage dryers, pipelines, condensing fans, vacuum solenoid valves, idlers and control systems.

The vast majority of cars, vans and minibuses use non independent air conditioners - air conditioning systems that operate directly from the car's engine. The compressor of the non independent air conditioner is driven by the main engine and controlled by the electromagnetic clutch. The utility model has the advantages of simple structure, convenient installation and arrangement, and low noise. The power consumption of main engine is 10% - 15%, which directly affects the acceleration performance and climbing ability of the vehicle. At the same time, its cooling capacity is affected by the vehicle speed.

2. Features of automobile air conditioning system

(1) The air conditioning device vibrates greatly during operation

It has been mentioned that the car air conditioning device is a mobile car air conditioning device. Because the road is uneven and the car bumps and vibrates greatly during driving, flexible refrigerant pipes should be used for connecting pipes in the device.

(2) The condenser is close to the radiator of the engine, so its condensation temperature is often very high, so its operating conditions are worse than other air conditioning devices.

(3) The compressor of the automobile air conditioning system is directly driven by the engine. When the compressor does not work, the compressor can be disconnected from the engine through an electronic clutch. When the sensor installed at the air outlet of the evaporator senses that the air temperature is not low enough, it will close the magnetic clutch of the compressor through the circuit.

In this way, the compressor runs with the engine to achieve refrigeration. When the air outlet temperature is lower than the set temperature, it controls the magnetic clutch to cut off, so that the compressor does not work.

When the car is idling, opening the air conditioner for cooling will obviously increase the idling speed, and the fuel consumption will also increase by 0.3-0.8L/H. The increase in fuel consumption is directly related to the ambient temperature. When the ambient temperature is high, the pressure of refrigerant expansion is high, and the consumption of the engine driven air conditioner will increase accordingly, and the fuel consumption will decrease correspondingly when the ambient temperature is low

The automobile air conditioning compressors are basically of constant frequency type, without power regulation. As long as the air conditioner is turned on, the fuel consumption is fixed, which has nothing to do with the air conditioning temperature. The higher the temperature regulation is, the higher the air outlet temperature will increase accordingly. The reason is that the hot water part of the air conditioning system is turned on, and hot air is sent in while cooling to neutralize the cold air to obtain the desired comfortable temperature

Principle of heating system: the heating of automobile air conditioner has nothing to do with the compressor. The heat source for heating is not obtained by the air conditioner itself, but is provided by the radiator tank of the automobile. There is basically no energy consumption, and it is completed by using the waste heat of the automobile (However, in winter, in order to increase the water temperature and fuel injection, the fuel consumption will also increase. But only in the initial stage of starting, when the engine runs normally, the heat dissipation of the engine will be used for heating.)

Dehumidification: The process of air conditioning refrigeration is the process of dehumidification, and the process of opening the air conditioner to remove fog is a dehumidification process