Refrigerant-134a enters an adiabatic compressor as saturated vapor at 0.18 MPa at a rate of 1.6 kg/s, and exits at 1 MPa and 60°C. The rate of entropy generation in the turbine is
A)0 kW/K
B)0.47 kW/K
C)3.34 kW/K
D)1.26 kW/K
E)14.1 kW/K "

Question

Quizplus · Accepted Answer

Solved by EES Software. Solutions can be verified by copying-and-pasting the following lines on a blank EES screen. 
P1=180 "kPa"
x1=1
m=1.6 "kg/s"
P2=200 "kPa"
T2=300 "C"
s1=ENTROPY(R134a,x=x1,P=P1)
s2=ENTROPY(R134a,T=T2,P=P2)
S_gen=m*(s2-s1) "kW/K"
"Some Wrong Solutions with Common Mistakes:"
W1_Sgen=0 "Assuming isentropic expansion"

Refrigerant-134a Enters an Adiabatic Compressor as Saturated Vapor at 0