Refrigeration Cycle: Understanding qL/wc & qH

In summary: It is important to calculate both qH and qL accurately in order to determine the true efficiency of the system.
  • #1
aaronfue
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I'm trying to get a good understanding of the two images attached.

So when calculating the coefficient of performance, I will need to use qL/wc. This is something that I've read in my textbook. Now when I was working with another student on this he told me that the work of the compressor will change due to qH? I'm not sure what he's talking about, and I think he just copied someone's work. And I thought that qH was to be calculated from: qH = h2 - h1. Is this not correct?

Can someone help me understand what is going on here?
 

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  • #2
The coefficient of performance (COP) is a measure of the efficiency of a refrigeration system, and it is calculated by dividing the heat removed from the low-temperature side (qL) by the work input on the compressor side (wc). qH is the amount of heat added to the high-temperature side of the system, and it is calculated by subtracting the enthalpy of the low-temperature side (h1) from the enthalpy of the high-temperature side (h2). The work of the compressor will not change due to qH, but the COP of the system will change depending on the value of qH. If qH is too low, then the COP will be lower than expected.
 

What is the refrigeration cycle?

The refrigeration cycle is a thermodynamic process that involves the transfer of heat from a lower temperature region to a higher temperature region. It is used in refrigerators, air conditioners, and other cooling systems to maintain a cold temperature.

How does the refrigeration cycle work?

The refrigeration cycle works by using a refrigerant, which is a substance with a low boiling point, to absorb heat from the surrounding environment. The refrigerant is compressed, which increases its temperature and pressure, and then it is condensed into a liquid. The liquid is then expanded, which causes it to cool down, and it is passed through an evaporator where it absorbs heat and turns back into a gas. This gas is then compressed again, and the cycle repeats.

What is qL/wc and qH in the refrigeration cycle?

qL/wc and qH are two important parameters in the refrigeration cycle. qL/wc represents the heat absorbed by the refrigerant in the evaporator, while qH represents the heat rejected by the refrigerant in the condenser. These values are used to calculate the coefficient of performance (COP) of the refrigeration cycle, which measures the efficiency of the system.

How do qL/wc and qH affect the efficiency of the refrigeration cycle?

The lower the value of qL/wc and the higher the value of qH, the more efficient the refrigeration cycle is. This is because a lower qL/wc means that the refrigerant is absorbing more heat from the environment, and a higher qH means that more heat is being rejected from the refrigerant. This results in a higher COP, indicating a more efficient refrigeration cycle.

What are some common applications of the refrigeration cycle?

The refrigeration cycle is used in various applications, including refrigerators, air conditioners, heat pumps, and refrigeration units in industries such as food processing and chemical manufacturing. It is also used in transportation systems such as refrigerated trucks and trains to transport perishable goods. The refrigeration cycle is essential for maintaining cold temperatures and preserving food and other products.

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