Pressure-enthalpy diagram (P-h) at various conditions

In vapor compression refrigeration cycle, the performance is changes as room or ambient conditions chage.

For a given condensing temperature (Tc),

• as Te increase, RE increase with W decrease, so COP increase
• as Te decrease, RE decrease, with W increase, so COP decrease

For a given evaporating temperature (Te),

• as Tc increase, RE decrease with W increase, so COP decrease
• as Tc decrease, RE increase, with W decrease, so COP increase

Where:

RE = Refrigerating effect or cooling capacity at evaporator

W = Work or power input to compressor

COP = Coefficient of performance = RE/W

Related notes:

Vapor compression refrigeration cycle key component

How the vapor compression refrigeration cycle work?

Pressure-enthalpy diagram for actual refrigeration system

Direct expansion or DX system