A heat engine receives heat from a source at 800 degree c an

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

solution :

W/Qh = (Th-Tc)/Th
(Qh - Qc)/Qh = (Th-Tc)/Th
(Qh-80)/Qh = (800-40)/(800+273)
Qh = 274.249

W = Qh - Qc = 194.249 kW