DieselShip's Online Content Library

Q6. A vapour compression refrigeration cycle operates between evaporation and condensation temperatures -15ºC and 35ºC respectively.

The refrigerant enters the compressor as a dry saturated vapour and the expansion valve as saturated liquid. Compression is regarded as isentropic.

Two refrigerants R134a and Ammonia are to be considered.

(a) Sketch the cycle on p-h and T-s diagrams.

(b) Determine EACH of the following:

(i) The specific work and compressor discharge temperature when using R134a

(ii) The specific work and compressor discharge temperature when using Ammonia

(iii) Which system requires the least work for the same cooling load.