Question

The vapour compression refrigeration cycle is represented as shown in the figure below, with state $1$ being the exit of the evaporator. The coordinate system used in this figure is

• A. $p-h$
• B. $T-s$
• C. $p-s$
• D. $T-h$

Answer 1

The correct option is D $T-h$


Process:

1-2: Isentropic (Reversible adiabatic) compression

2-3: Constant pressure heat rejection

3-4. Throttling (Isenthalpic) expansion

4-1: Constant pressure heat absorption

As in VCRS process 3-4 is an adiabatic throttling process in which enthalpy remains constant $(h_3=h_4)$.

So, option (b) and (c) is ruled out. As process $2-3$ is reversible constant pressure process first desuperheated and then condensed, ending with saturated liquid.

Heat $Q_1$,is transferred out, so option (a) is ruled out so, we will be left with option (d) only.