Section 3 - Service and Repair
REFRIGERATION SYSTEMS
Normal Vapor/Compression Cycle Refrigeration
•Refrigerant is pumped from the compressor to the condenser as a high pressure, high temperature vapor.
•As the refrigerant cools in the high pressure condenser, the vapor condenses to liquid. During this phase change, a great amount of heat is rejected with the help of the condenser fan.
•The liquid then flows to the dryer where is strained and filtered.
•From the dryer, the refrigerant flows through the capillary tube which meters the liquid refrigerant to the evaporator.
The pressure of the refrigerant is reduced to the evaporating, or low side, pressure.
•The reduction of pressure on the liquid refrigerant causes it to boil, or vaporize, until it reaches saturation temperature. As the low temperature refrigerant passes through the evaporator coil, it continues to absorb a lot of heat, causing the boiling action to continue until the refrigerant is completely vaporized. It is during this phase change that most heat is absorbed (the cooling takes place) in the refrigerator.
•The refrigerant vapor leaving the evaporator travels through the suction line to the compressor inlet. The compressor takes the low pressure vapor and compresses it, increasing both pressure and temperature. The hot high pressure gas is pumped out the discharge line and into the condenser. The cycle then repeats.
COMPRESSOR |
CONDENSER |
DRYER |
EVAPORATOR |
CAPILLARY TUBE |
Figure 1. Normal Vapor/Compression Cycle Refrigeration System |