Compressor

Gas from the evaporator in the point 2 now enters the compressor and changes in conditions of high temperatures and pressure superheated gas. He leaves the compressor at point 3. The compressor has changed refrigerant pressure from 83.4 PSIA (69 PSIG + 14.7 psi) 277.7 PSIA (263 PSIG + 14.7 psi). Along with this change of pressure is changing the saturation temperature from 40F to 120F. superheated gas currently about 165F. Thus, it contains about 45F overheating (165F - 120F = 45F).

Enthalpy of the refrigerant increased by approximately 110 Btu/lb at the compressor inlet (paragraph 2) of 125 Btu/lb at the outlet of the compressor (point 3). The heat was added because the compressor worked on the gas to increase its pressure. This additional heat is called the heat of compression. In this example, it is about 15 Btu/lb (125 Btu/lb -110 BTU/pound), or about 22% of the additional heat, for that absorbed in the evaporator.

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