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Thermodynamics heat engine Question

  1. Aug 23, 2011 #1
    1. The problem statement, all variables and given/known data
    A 1500kW heat engine operates at 25% efficiency. The heat energy expelled at the low temperature is absorbed by a stream of water that enters the cooling coils at 20 degrees C. If 60L flows across the coils per second, determine the increase in temperature of the water.

    2. Relevant equations
    mCdeltaT = Q

    3. The attempt at a solution
    0.75*(1500Kj/s)(1000J/1kJ)(s/60L)(kgdegreesC/4186J) = 4.48
    The book says that it is 18 degrees C. The DA that I did cancels out correctly though.

  2. jcsd
  3. Aug 23, 2011 #2


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    Homework Helper

    You need to convert the 60L/s to mass flow rate in kg/s, you would need to find how many kg is in 1 L.
  4. Aug 23, 2011 #3
    It's water, so with a density of 1, the answer should still be what I got.
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