Advantages: Cooling the air /Comfort/safety Dry air Clean air
Components of air condition
1. 2. 3. 4. 5. 6. 7.
Compressor Condenser and Fan Pressure control switch Reciever / Drier Expansion valve Evaporator Heat exchanger
8.
Blower
Physical and technical law of air conditioning
What is cooling?
Cooling is the transport of heat energy from a place we don`t want to have to a place where it is no problem
Possibilitys:
Latent heat of evaporation-----------------------------------Latent heat of condensation
Cold air inside 10°C for example 35°C ice
0°C
0°C
liquid
Warm ambient air 35°C for example
-30°C
Boiling temperature and pressure of water
Boiling temperature of water in °C
presure in bar (absolut
151 100 68 12,7 6,7
5 1 0,3 0,015 0,010
Condensation of water
vapor Air
100°C Water Water
Refrigerant R 134
pressure in bar boiling temperature in °C
0
-26,5
1
-9
2
+2
3
+11
4
+18
5
+25
6
+31
Evaporation
+ 10°C
- 9°C
16 bar
7 bar R 1 bar
A + 27°C R134a - 9°C + 27°C
B
- 20°C vapor
40°C Still liquid
Ice cold
liquid
vapour liquid cold - warm vapour
vapour
Ice cold
hot
liquid
warm
Refrigerant and Ozon Stratosphare 15 – 60 km
Refrigerant and green house effect
Green house potential
Cars
3 up to 16 hp
Busses
up to 50 hp
Cutaway of typical swash plate piston compressor (double side working Pistons)
1. 2. 3. Shaft Swash plate Double piston
4.
5.
Valve plates
Magnetic clutch
Cutaway of typical swash plate piston compressor (single side working Pistons)
Variable displacement compressor Control Valve
bellows Chamber pressure
High pressure
low pressure
1) control valve 2) regulation pressure 3) sliding shaft
4) spring 5) throttle bore
Rotary vane compressor
Scroll type compressor
Refrigerant oil
Compressor
Condenser
Drier
Evaporator
Hoses Drier Hose 15 ccm/ml
5 ccm/ml/m
40 ccm/ml 40 ccm/ml
Refrigerant oil wich is taken from the system during discharging must be filled into the system after vacuum.
Evaporator Condenser
also when system components are replaced we have to fill oil into the system
Accident 50 ccm/ml suddenly discharged
Electro-magnetic clutch
1 Fixing screw 2 Disk 3 Front plate 4 Rotor assembly
Condenser
Problems:
•Dirty •Leaking •Corrosion •Fan vapor insects / flies stones inside / outside out of order liquid
Reciever / Drier
Funktion / Purpose
•To act as drier for the refrigerant •To act as filter for the refrigerant •To act as reservoir for the refrigerant •Change gas bubbles to liquid
•Damper for refrigerant vibrations
•Contains the sight glass
Important:
Drier has to be changed, when the sytem has been open or leaking for more then 5 minutes Drier should be changed every two years
Switch off pressure: About 2.0 bar (in HP) About 1.0 bar (in LP) Not enough refigerant inside system About 30 bar Always installed in HP Pressure in sytem to high
1. 2.
HP switch LP switch
3.
Switch on the second stage of condenser fan at about 18 bar
Electrical circuit with double pressure switch
Line 15 Main switch HP/LP switch Termostat
Magnetic clutch
Pressure switch check
Pressure sensor
Always installed in HP side
Signal to ECU Never install a bridge
Pressure about 2.0 bar Plus supply from ECU
PWM Signal Microprocessor
Periode
Puls wide
Pressure about 30 bar
Periode
Voltage Signalvoltage Siliciumresistor
Puls wide
Electrical circuit
Typical electrical circuit for air conditioning system without electronical control