GF83.40-P-2005CA Automatic Air Conditioning Refrigerant Circuit, Function

GF83.40-P-2005CA Automatic Air Conditioning Refrigerant Circuit, Function
MODEL 207.3/ 4





1 Capacitor
2 Fluid reservoir
3 Expansion valve
4 Evaporator
A9 AC compressor
B10/6 Evaporator temperature sensor
B12 Refrigerant pressure sensor
A High pressure, gaseous
B High pressure, liquid
C Low pressure, liquid
D Low pressure, gaseous

Function requirements, general
^ Engine running
^ Automatic air conditioning switched on

Automatic air conditioning refrigerant circuit, general
The cooling output is controlled by the automatic air conditioning control and operating unit (N22/7).
The automatic air conditioning refrigerant circuit mainly consists of the following components:
- AC compressor
- Capacitor
- Fluid reservoir
- Expansion valve
- Evaporator
- Hoses and pipelines
The individual components of the refrigerant circuit are interconnected through hoses and pipelines and form a closed system.
The automatic air conditioning refrigerant circuit function consists of the following functional components:
^ Function sequence for high-pressure side
^ Function sequence for low-pressure side
The separation points for this are the valve plate at the refrigerant compressor and the injection valve at the expansion valve.

Function sequence for high-pressure side
The refrigerant compressor driven by the engine draws in the cold gaseous refrigerant from the evaporator, compresses it, whereby it is heated, and delivers it to the condenser. The compressed hot refrigerant is cooled in the condenser by the outside air flowing past. On reaching the dew point dependent on the pressure, the refrigerant condenses and changes in terms of its physical state from gaseous to fluid.
The completely liquefied refrigerant then flows into the fluid reservoir (drier).
While it is flowing through the fluid reservoir, moisture is removed from the refrigerant and it is cleansed of any chemical and mechanical impurities in order to protect the subsequent components. The cleaned refrigerant then flows to the expansion valve. The liquid refrigerant, which is under high pressure, is injected into the evaporator.
The refrigerant pressure is recorded by the refrigerant pressure sensor

Function sequence for low-pressure side
The liquid refrigerant decompresses in the evaporator and changes again in terms of its physical state from fluid to gaseous.
The evaporation heat required for the evaporation is removed from the air flowing past at the evaporator fins, cooling it down in the process. The refrigerant, which is completely gaseous once more, is drawn in again and compressed by the refrigerant compressor.
As of 1.12.09 in model 207.3 and in model 207.4, a coaxial heat exchanger is installed. This increases the output and efficiency of the refrigerant circuit.
To prevent the evaporator from icing up, if the temperature drops below a specific value at the evaporator, the refrigerant compressor is switched off by the control and operating unit.
The evaporator temperature is recorded by the evaporator temperature sensor.