What is Vapor Compression Refrigeration System
A vapour compression refrigeration system uses a refrigerant sealed in an airtight and leak proof mechanism. The refrigerant is circulated through the system and it undergoes a no of changes in its state while passing through various components of the system. Each such change in the state of vapour is called a process. The process of repetition of a similar order of operation is called a cycle.
The compression cycle is given this name because it is the compression of the refrigerant by the compressor which permits transfer of heat energy. The refrigerant absorbs that from one place and release it to another place. In other words the compressor is used to put the heat laden refrigerant vapour in such a condition that it may dispute the heat it absorbed at low pressure from the refrigerated space, to an easily available cooling medium.
VAPOR COMPRESSION REFRIGERATION CYCLE:
Most of the modern refrigerators work on this cycle. In its simplest form there are four fundamental operations require to complete one cycle.
· Compression: The low pressure vapor in dry state is drawn from the evaporator during the suction stroke of the compressor. During compression stroke the pressure and temperature increase until vapor temperature is greater than the temperature of condenser cooling medium.
· Condensation: When the high pressure refrigerant vapor enters the condenser heat flows from condenser to cooling medium thus allowing the vaporized refrigerant to return to liquid state.
· Expansion: After condenser the liquid refrigerant is stored in the liquid receiver until needed. From the receiver it passes through an expansion valve where the pressure is reduced sufficiently to allow the vaporization of liquid a low temperature of about -10C.
· Vaporization: The low pressure refrigerant vapour after expansion in the expansion valve enters the evaporator or refrigerated space where a considerable amount of heat is absorbed by it and refrigeration is furnished.