Helium undergoes a Stirling refrigeration cycle, which is a reverse Stirling power cycle. At the beginning of

Question:

Helium undergoes a Stirling refrigeration cycle, which is a reverse Stirling power cycle. At the beginning of isothermal compression helium is at 100 kPa, 275 K. The compression ratio is 4 and during isothermal expansion the temperature is 150 K. Determine per kg of helium, (a) the net work per cycle, (b) the heat transfer during isothermal expansion, and (c) the COP.