Air Conditioner: Refrigerator or Heat Pump?

AI Thread Summary
Air conditioners function similarly to refrigerators, utilizing refrigerants that change phases to absorb heat. In the given scenario, 7.00 kg of refrigerant enters the evaporator with 54% as liquid and 46% as vapor. The calculation for heat absorbed (Qc) initially misinterpreted the mass of vapor, leading to an incorrect total energy release. The correct approach requires calculating the energy needed to vaporize the remaining liquid, which is 49% of the total mass. Accurate calculations are essential for understanding the heat absorption process in air conditioning systems.
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Homework Statement


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 (Qc) is absorbed by the refrigerant while it is in the evaporator? The heat of vaporization of the refrigerant is 1.50×105 J/kg .


Homework Equations



Qc = Mv*Lv
Mv = Mass of vapor
Lv=heat of vaporization

The Attempt at a Solution



I calculated what is the mass of the vapor
M of liquid = 7 kg *54% = 3.78kg
M of vapor = 7 kg - 3.78kg = 3.22kg
then Qc = Mv*Lv
3.22 * 1.50*10(5) = 483000 J

Please.. help me..
thank you
 
Physics news on Phys.org
You have calculated the energy that would be released if all of the vapor condensed. What is wanted is the energy to vaporise an additional (54%-5%) of the total mass.
 

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