In a refrigerator using R134a, evaporation takes place at 0.14 MPa, and the resulting vapour enters the compressor at -10 C .The vapour is then…

In a refrigerator using R134a, evaporation takes place at 0.14 MPa, and the resulting vapour enters the compressor at -10. The vapour is then compressed to 1.2MPa, and the temperature of the vapour leaving the compressor is 80.

i. Sketch the two processes on sketches of the T-S and P-h diagrams

ii. What state is the refrigerant when it enters the compressor?

iii. Calculate the isentropic efficiency of the compressor, stating all your assumptions clearly.