Sonntag, Borgnakke and van Wylen
7.44 A car engine burns 5 kg fuel (equivalent to addition of QH) at 1500 K and rejects energy to the radiator and the exhaust at an average temperature of 750 K. If the fuel provides 40 000 kJ/kg what is the maximum amount of work the engine can provide? Solution: A heat engine QH = m qfuel = 5 × 40000 = 200 000 kJ Assume a Carnot efficiency (maximum theoretical work) TL 750 η = 1 − T = 1 − 1500 = 0.5 H W = η QH = 100 000 kJ
Air intake filter Shaft power
Exhaust flow
Coolant flow
Fan Radiator Atm. air