A compressor brings R-134a from 140kPa, -10 C to 1200 kPa, 50 C. It is water cooled with heat
loss estimated to 40kW and the shaft work input is measure to be 150 kW. What is the mass flow
rate through the compressor?
Professor gave us the answer of 3.45 kg/s. Not sure what tables to look up the information for the
coolant on. Any help is appreciated. Step by step please.
Solution
C.V compressor steady flow
Neglect kinetic & potential energy
Energy mHi + Q = mHe + W
m = (Q - W)/(He - Hi)
Q = -40, W = -150
To get, He & Hi use table given to you,

m = 110/(He - Hi)
(You didn't provide table, this will be some enthalpy table for water which will give you value
of enthalpy for given pressure & temperature)
value for hi ( 140kPa, -10 C) will be in between 390 to 410 & for he( 1200 kPa, 50 C) it will be
around (hi + 31).
put value of He & Hi you will get m.