A heat engine receives heat from a source at 800°C and rejects the waste heat to a sink at 40°C. If heat is rejected from this engine at a rate of 80 kJ/s, the maximum power this heat engine can produce is

Question

Quizplus · Accepted Answer

Solved by EES Software. Solutions can be verified by copying-and-pasting the following lines on a blank EES screen. 
TH=800 "C"
TL=40 "C"
QL=80 "kW"
Eta=1-(TL+273)/(TH+273)
QH=QL/(1-Eta)
W_out=Eta*QH
"Some Wrong Solutions with Common Mistakes:"
Eta1=1-TL/TH
QH1=QL/(1-Eta1)
W1_Wout=QH1-QL "Using temperatures in C"
W2_Wout=QL "Setting work equal to heat output"
QL/QH3=TL/TH 
W3_W_out=QH3-QL "Using temperature ratio"

A Heat Engine Receives Heat from a Source at 800°C