Air conditioning device
The air conditioning system consists of the following main elements: compressor, condenser, evaporator and piping. The structure of the air conditioning system is shown in Figure 2-1.
Figure 2-1 - Arrangement of the air conditioning system: 1 - capacitor; 2 - pipeline connecting the compressor with the evaporator (long part); 3 - pipeline connecting the condenser to the evaporator; 4 - pipeline connecting the compressor with the evaporator (short part); 5 - thermostatic valve; 6 - evaporator; 7 - compressor; 8 - pipeline connecting the compressor with the condenser; 9 - pressure sensor
The general scheme of the circuit of the air conditioning and ventilation system is shown Here.
2.1. Compressor: 1 - a pulley with an electromagnetic clutch; 2 - output of the wires of the electromagnetic clutch; 3 – back cover; 4 - body; 5 - front cover
Piston type compressor. The compressor creates the pressure necessary for the operation of the air conditioning system and circulates the refrigerant. The compressor is mounted on the engine under the generator. Torque is transmitted to the compressor shaft from the crankshaft by a V-ribbed belt through an electromagnetic clutch.
2.2. Capacitor: A - receiver-drier
The condenser, through heat exchange with the surrounding air, cools the gaseous refrigerant at high temperature and under high pressure, condenses it into a liquid refrigerant. The condenser is mounted on the radiator frame in front of the cooling system radiator.
2.3. Evaporator
The evaporator cools and dehumidifies the air inside the car by exchanging heat with the refrigerant. The evaporator unit is installed in the heater housing in front of the heater core.
2.4. Receiver dryer
The receiver-drier is designed to accumulate refrigerant in a liquid state, to separate moisture and possible mechanical particles from it. The receiver-drier is mounted on the condenser. The receiver has a built-in filter-drier.
2.5. Pipelines
Pipelines connect the elements of the air conditioning unit to each other by means of flange connections.
2.6. expansion valve
To regulate the flow of refrigerant from the condenser to the evaporator, a thermostatic expansion valve is installed in front of the evaporator (TRV).
2.7. Pressure meter
Pressure meter (DD) installed in the pipeline connecting the compressor and condenser. DD gives a signal to the ECM to turn off / turn on the compressor when there is a deviation (raising or lowering) pressure from the working value.
2.8. Heating, air conditioning and ventilation control unit
The air conditioning system is controlled by the heating, air conditioning and ventilation control unit (BOO), located at the bottom of the center console of the instrument panel. The location and purpose of the VU controls is shown in Figure 2-2.
Figure 2-2 - Purpose of the controls of the heating, air conditioning and ventilation control unit: 1 - handle for controlling the direction of the air flow; 2 - button for turning on the air conditioner; 3 - recirculation control handle; 4 - handle for controlling the speed of the air flow; 5 - air flow temperature control knob
Attention. Work on the air conditioning system must only be carried out by suitably trained personnel.
When performing work, it is allowed to use standardized equipment and tools that are functionally similar to those specified in the manual, the use of which ensures the required performance, safety and quality of work.
When carrying out any type of work on the car related to the depressurization of the air conditioning system, completely unload the refrigerant and then load the system. Works on unloading, loading and detecting refrigerant leaks should be carried out in accordance with the operating instructions for the service equipment and the leak detector.
When the engine is not running, charge the refrigerant through the high pressure circuit. The mass of refrigerant charged into the system (R134a) is 475±35 g. If the system is not fully loaded with refrigerant, additional loading should be carried out with the engine running and the air conditioning system turned on through the low-pressure gaseous refrigerant circuit.
To prevent damage to filling equipment or personal injury, it is strictly forbidden to open the valves on the high pressure circuit (red service hose) when the air conditioning system is loaded with refrigerant. All work with refrigerant must be carried out with goggles with side protection.
When replacing the elements of the air conditioning system, it is not allowed to remove the technological plugs from the fittings until each of the elements is prepared for connection. Care must be taken when removing the process plugs from the fittings of the air conditioning units to avoid injury, as they are pressurized with nitrogen gas.
Attention. When replacing any of the elements of the air conditioning system (condenser, evaporator, etc.) be sure to replace the o-rings.
When carrying out welding work on a car in the immediate vicinity of the elements of the air conditioning system, perform a complete unloading of the refrigerant from the system.