Air Conditioner: Refrigerator or Heat Pump?

In summary, an air conditioner operates on the same principle as a refrigerator and has 7.00 kg of refrigerant flowing through its circuit each cycle. The refrigerant enters the evaporator in phase equilibrium, with 54.0% of its mass as liquid and the rest as vapor. After flowing through the evaporator at a constant pressure, 95% of its mass is vapor when it reaches the compressor. To find the heat absorbed by the refrigerant in each cycle, we use the equation Qc = Mv * Lv where Mv is the mass of vapor and Lv is the heat of vaporization. By calculating the mass of vapor and using the given value for Lv, we find that the heat absorbed is 483000
  • #1
xinlan
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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
 
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  • #2
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.
 

1. What is the function of an air conditioner?

An air conditioner is a device that cools and dehumidifies the air in a room or building. It works by pulling in warm air from the room, passing it through a refrigerant-filled coil to cool it, and then blowing the cool air back into the room.

2. Is an air conditioner a refrigerator or a heat pump?

An air conditioner can function as both a refrigerator and a heat pump. In cooling mode, it works like a refrigerator, removing heat from the air and expelling it outside. In heating mode, the process is reversed, and heat is extracted from the outside air and transferred inside.

3. How does an air conditioner use refrigerant to cool the air?

An air conditioner uses a refrigerant, such as Freon, to transfer heat from the air inside to the air outside. The refrigerant is compressed, which causes it to turn into a high-pressure, high-temperature gas. As it passes through the condenser coils, the heat is released into the outside air, and the refrigerant turns back into a liquid. Then, the liquid refrigerant is passed through the evaporator coils, where it absorbs heat from the indoor air and turns back into a gas, cooling the air in the process.

4. How does an air conditioner regulate the temperature in a room?

An air conditioner has a thermostat that measures the temperature of the air in the room. When the desired temperature is reached, the thermostat signals the air conditioner to stop cooling. If the temperature rises above the set point, the air conditioner will turn back on to bring the temperature back down.

5. What is the difference between a window air conditioner and a central air conditioner?

A window air conditioner is a self-contained unit that is installed in a window and cools a single room. A central air conditioner, on the other hand, is a larger system that is connected to ductwork and cools an entire building. Central air conditioners are more efficient and can cool multiple rooms at once, but they are more expensive to install and require professional maintenance.

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