Liquid kerosene with a specific heat of 2.0 kJ/kg.°C enters an adiabatic piping system at 18° at a rate of 3 kg/s. If the water temperature rises by 0.4°C during flow due to friction, the rate of entropy generation in the pipe is
A)132 W/K
B)44 W/K
C)8.2 W/K
D)2.7 W/K
E)89 W/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. 
Cp=2000 "J/kg.K"
m=3 "kg/s"
T1=18 "C"
T2=18.4 "C"
S_gen=m*Cp*ln((T2+273)/(T1+273)) "W/K"
"Some Wrong Solutions with Common Mistakes:"
W1_Sgen=m*Cp*ln(T2/T1) "Using deg. C"
W2_Sgen=Cp*ln(T2/T1) "Not using mass flow rate with deg. C"
W3_Sgen=Cp*ln((T2+273)/(T1+273)) "Not using mass flow rate with deg. K"

Liquid Kerosene with a Specific Heat of 2