Refrigerant Compressor is used to compress the vapour refrigerant from the evaporator. It works as the pump to control the refrigerant circulation. It raises the pressure so that the corresponding temperature is higher than the cooling medium. Compression process requires work to be done on it, the compressor must be driven by some mover.
- Suction Pressure: Pressure of the refrigerant at the inlet.
- Discharge pressure: Absolute Pressure of the refrigerant at the outlet.
- Compression Ration: Ratio of discharge pressure to the suction pressure. It is always greater than unity as discharge pressure is always greater than suction pressure.
- Swept Volume: It is the volume swept by the piston when it moves from one dead centre to another dead centre. It is denoted by Vp
Vp = π/4 x D ² x L
D = Diameter of the cylinder
L = Length of the stroke.
- Clearance Factor: It is the ratio of clearance volume to the swept volume. It is represented by C
C = Vc/Vp
- Compressor Capacity: The amount of refrigerant passing through the compressor in a unit time. It is equivalent to the suction volume.
- Volumetric Efficiency: It is the ratio of the suction volume to the swept volume.
η = Vs/Vp
Classification Refrigerant Compressor
1.According to the method of compression.
b) Rotatory Compressor
c) Centrifugal Compressor
2. According to the number of strokes
b) Double acting
3. According to the number of stages
a) Single Stage
b) Multi Stages
4. According to the method of drive employed
a) Direct Drive
b) Belt Drive
5. According to the location of prime movers