Refrigerant R-134a enters the compressor of a refrigeration machine at 140 kPa pressure and -10 °...

Refrigerant R-134a enters the compressor of a refrigeration machine at 140 kPa pressure and -10 ° C temperature and exits at 1 MPa pressure. The volumetric flow of the refrigerant entering the compressor is 0.23 m3 / minute. The refrigerant enters the throttling valve at 0.95 MPa pressure and 30 ° C, exiting the evaporator as saturated steam at -18 ° C. The adiabatic efficiency of the compressor is 78%. Show the cycle in the T-s diagram. In addition,

a) the power required to start the compressor,
b) Heat drawn from the cooled medium per unit time, COP_SM =?

c) Calculate between the evaporator and the compressor, how much the pressure of the refrigerant drops and how much the heat gain is.

Expert Solution

samet mamat answered 1 year ago

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