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

GF83.40-P-2005CE Automatic Air Conditioning Refrigerant Circuit, Function
MODEL 204.0 /2 as of model year 2009 /YoM 08
MODEL 204.3
MODEL 204.9





1 Capacitor
2 Fluid reservoir
3 Expansion valve
4 Evaporator
A9 Refrigerant compressor (without code (B09) Refrigerant compressor with magnetic clutch)
A9/7 Refrigerant compressor with magnetic clutch (with code (B09) Refrigerant compressor with magnetic clutch)
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
^ Engine running
^ Air conditioning switched on

Automatic air conditioning refrigerant circuit, general
Control of the automatic air conditioning refrigerant circuit is performed by the automatic air conditioning control and operating unit (N22/7). The air in the vehicle interior is cooled depending on the setting on the control and operating unit or rear automatic air conditioning control unit (N22/4) (with code (581) comfort automatic air conditioning ) by the automatic air conditioning refrigerant circuit. The individual components are interconnected through lines and form a closed system.
The automatic air conditioning refrigerant circuit 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, 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 refrigerant flows from the condenser to the fluid reservoir (drier) via a line. While it is flowing through the fluid reservoir, moisture is removed from the refrigerant, vapor locks are separated and it is cleansed of any 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.

Function sequence for low-pressure side
The liquid refrigerant evaporates in the evaporator and changes its state again 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 and compressed by the refrigerant compressor. The cooled air is led to the vehicle interior via the blower motor (A32m1).
As of 1.12.09 a coaxial heat exchanger will be 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.