Subcooling is a process of cooling the refrigerant in the vapour

SOLUTION

Vapour Compression Refrigeration System:

With Subcooling:

In the above figure

Process 1-2-3-4 is an ideal representation of the vapour compression cycle

Process 1-2-3’-4’ is the vapour compression cycle with subcooling

Now in the cycle following are the processes

1-2: compression process

2-3: condensation process

3-4: expansion process

4-1: evaporation process

Now in the cycle with subcooling, everything remains the same except the expansion process will become (3’-4’)

And 3-3’: subcooling process

Hence from the above-mentioned sequence, we can see that the subcooling process (3-3’) occurs before the expansion process (3’-4’)