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Refrigerant Circuit, Basic Function - GF83.40-P-1001A

Model all (CAR) 

Overview 

This document contains information on:

General 

In the refrigerant circuit, the pressures and the physical states of the refrigerant change. It absorbs heat and releases it again elsewhere. The refrigerant circuit is regulated via the climate control controller. The refrigerant circuit consists of a low-pressure side and a high-pressure side, which are separated, depending on equipment, by one or more valves and by the refrigerant compressor.

The refrigerant circuit can be filled with the synthetic refrigerants R134a or R1234yf.

Function requirements 

Function 

Refrigerant circuit 

The individual components of the refrigerant circuit are interconnected through hoses and pipelines and form a closed system. The refrigerant circuit essentially consists of the following components:

High-pressure side 

The refrigerant compressor draws in the gaseous refrigerant from the evaporator, compresses it and routes it into the condenser. The compressed, hot coolant is cooled there by the passing airstream or by the coolant depending on the equipment installed.

Due to the cooling, the gaseous refrigerant changes its physical state and liquefies. The liquid refrigerant then flows through the drier. The drier draws moisture from the refrigerant, separates out vapor locks and filters out mechanical impurities.

After the drier, the refrigerant reaches the expansion valve, where it sprays into the evaporator under high pressure.

Low-pressure side 

In the evaporator, the refrigerant decompresses and changes its physical state from liquid to gas. The refrigerant takes the heat it requires for evaporation from the passing airstream, which is cooled in the process. The refrigerant compressor draws in the now gaseous refrigerant and compresses it.

G15046611Courtesy of MERCEDES-BENZ USA

Refrigerant circuit (shown schematically on model 177) 

IMPORTANT The condenser is either water-cooled (electric vehicles) or air-cooled depending on the equipment installed in the vehicle. Thermal or electric expansion valves are installed depending on equipment.

IMPORTANT Model all (CAR)

with code 582 (Air conditioning, rear)

A second evaporator circuit is also present.

  Further basic function     
  Climate control, basic function   GF83.00-P-9901A 
  Expansion valve, basic function   GF83.40-P-2018A 
  Electric refrigerant compressor, basic function   GF83.55-P-2000A 
  Mechanical refrigerant compressor, basic function   GF83.55-P-2001A 
  Component descriptions     
  Low-temperature circuit switchover valve, component description Model 243 GF20.10-P-3002B
  High-voltage battery cooling shutoff valve, component description Model 243 GF20.10-P-3003B
  Heat exchanger temperature sensor, component description Model 243 GF83.57-P-2134B