Calculating Heat Exhaust from a Heat Engine

[flower76]

I'm not sure if I'm interpreting this question correctly

A heat engine operated between 40C and 380C. Being a real engine, it efficiency is only 60% of that theoretically possible for a Carnot engine at these temperatures. If it absorbs heat at a rate of 60kW at what rate does it exhaust heat?

So should I be finding the ideal (Carnot engine) and then taking 60% of that?

ideal = 1-Tl/Th = 1- (313K/653K) = 0.52

so then I figured it runs at 60% of ideal so e should be 0.312

Is this right or is e just 60% ??

 

[Cyrus]

You are almost there. You did not answer what the question asked of you, it said what rate does it exhaust heat, not the efficiency.

 

[flower76]

If e is 0.312

then 0.312 = (Qh-Ql)/Qh
0.312 = (60 kJ/s - Ql)/60 kj/s

Ql = 41.3 kj/s So it exhausts at a rate of 41.3 kj/s

Does this look right?

 

[Cyrus]

seems reasonable.