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What refrigerant(s) must be recovered before opening a system or disposing of a system?

User Aeubanks
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Final answer:

In a refrigeration cycle with a coefficient of performance (K_R) of 3.0, a refrigerator removing 200 J of work will extract 600 J from the cold reservoir and discard 800 J to the hot reservoir. Recovering refrigerants such as HCFCs and HFCs before system disposal is crucial for environmental protection.

Step-by-step explanation:

The question pertains to the refrigeration cycle and the coefficient of performance (KR) of a refrigerator. In a refrigeration cycle, a refrigerator must remove heat from its cold reservoir and expel heat to its hot reservoir while requiring work to operate.

For a refrigerator with a coefficient of performance of 3.0 that requires 200 J of work per cycle, the amount of heat removed from the cold reservoir (Qc) can be calculated.

  1. Calculate the heat removed (Qc): The coefficient of performance (KR) is given by KR = Qc / W, where W is the work done.
  2. Substitute the known values: With KR = 3.0 and W = 200 J, Qc = KR × W = 3.0 × 200 J = 600 J. So, 600 J of heat is removed from the cold reservoir per cycle.
  3. Calculate the heat discarded (Qh): We know that Qh = Qc + W. Thus, Qh = 600 J + 200 J = 800 J. This means 800 J of heat is discarded to the hot reservoir per cycle.

The refrigerants that need to be recovered before opening or disposing of a system include substances such as hydrochlorofluorocarbons (HCFCs) like HCFC-22, HCFC-123, and HCFC-124, as well as hydrofluorocarbons (HFCs) like HFC-134a. These are important to prevent environmental damage as some refrigerants deplete the ozone layer or contribute to global warming.

User Bushwacka
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