Refrigerant R-134a enters the compressor of a refrigerationmachine at 140 kPa pressure and -10 ° C temperature and exits at 1MPa pressure. The volumetric flow of the refrigerant entering thecompressor is 0.23 m3 / minute. The refrigerant enters thethrottling valve at 0.95 MPa pressure and 30 ° C, exiting theevaporator as saturated steam at -18 ° C. The adiabatic efficiencyof the compressor is 78%. Show the cycle in the T-s diagram. Inaddition,
a) the power required to start the compressor,
b) Heat drawn from the cooled medium per unit time,COPSM =?
c) Calculate between the evaporator and the compressor, how muchthe pressure of the refrigerant drops and how much the heat gainis.
