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Homework Help: An Air Conditioner: Refrigerator or Heat Pump?

  1. Nov 28, 2006 #1
    Air conditioners operate on the same principle as refrigerators. Consider an air conditioner that has 7.00 kg of refrigerant flowing through its circuit each cycle. The refrigerant enters the evaporator coils in phase equilibrium, with 54.0% of its mass as liquid and the rest as vapor. It flows through the evaporator at a constant pressure and when it reaches the compressor 95% of its mass is vapor. In each cycle, how much heat Q_c is absorbed by the refrigerant while it is in the evaporator? The heat of vaporization of the refrigerant is 1.50×105 kg/J

    All right I don't know what to do
    I know I have to find the percentage of refrigerant transformed to vapor which is 49%
    Now I have to calculate the heat needed to transform this amount of refrigerant to vapor. But I don't know how, I just need the absic equation please help.
  2. jcsd
  3. Nov 28, 2006 #2


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    Find the mass of the liquid that gets converted to to vapor using the percentages. Check the units on the heat of vaporization. Did you type that correctly?
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