A totally reversible heat engine operates between a source a

A totally reversible heat engine operates between a source at 527C and a sink at 7C. At what rate must heat be supplied to this engine, in kJ/h, for it to produce 4 kW of power?

Solution

>> Reversible heat Engine

>> T1 = Source Temperature = 527 C = 800 K

>> T2 = Sink Temperature= 7 C = 280 K

>> Power Produced, W = 4 kW

>> Let Heat Supplied to Heat Engine from source = Q1 = ?

As, Efficiency = Work Done/Heat Input in heat engine = W/Q1

As, Reversible heat engines are Carnot Engines.

So, Efficiency = 1 - T2/T1

=> W/Q1 = 1 - T2/T1

=> 4/Q1 = 1 - 280/800

Simplifying,

Q1 = Heat Supplied to Engine = 6.154 kW .......ANSWER........