Single-stage cycle of a pure refrigerant or an azeotrope
Refrigerating machines theory - Mechanical compression machines. Single-stage cycles

The basic single-stage compression cycle and the ideal temperature profile of the refrigerant and the cold and hot heat transfer fluids in the exchangers of this system are shown in figure 1.

The simple, highly symmetrical single-stage compression machine comprises the following components.

The evaporator vaporizes the refrigerant, removing heat from the coolant, which cools from q_f1 to q_f2. The vapor leaving the evaporator is saturated. Evaporation takes place at the vaporization temperature q_F, corresponding to the evaporation pressure p_F. We have :