Question

System dependent (passive) refrigerant recovery of small appliances: _______

1) Do not require an operation compressor.
2) Requires 80
3) Recovers refrigerant in a non-pressurized container.
4) All of the above.

Answer 1

The correct answer to the student's question about system dependent refrigerant recovery of small appliances is that these systems do not require an operational compressor.

System Dependent Refrigerant Recovery of Small Appliances

When it comes to the system dependent (passive) refrigerant recovery of small appliances, several characteristics define the process, including that it:

1. Does not require an operational compressor.
2. Recovers refrigerant in a non-pressurized container, which implies the recovery unit relies on the pressure of the appliance to move the refrigerant.

Therefore, the correct option for the student's question is 1) Do not require an operational compressor, as the other statements given do not accurately describe system dependent refrigerant recovery.

Options 2 and 3 are not related to system dependent recovery specifically and, thus, indicating 'All of the above' would be incorrect.

Option 2 mentioning 'Requires 80' appears to be incomplete and is not applicable without further context.

Understanding Refrigerators and Heat Pumps

Refrigerators and heat pumps operate on the principle of moving heat from one area to another.

For example, a refrigerator removes heat from its interior (cold reservoir) and expels it to the external environment (hot reservoir).

This process can be quantified using the coefficient of performance (COP), which indicates the effectiveness of the appliance in transferring heat relative to the work it consumes.

Hence, in the student's additional question:

• If a refrigerator has a COP of 3.0 and requires 200 J of work per cycle, it removes 600 J of heat per cycle from the cold reservoir (because COP is the ratio of heat removed from the cold reservoir over the work input).
• Therefore, it also discards 800 J of heat per cycle to the hot reservoir (the sum of the work done plus the heat removed).

Understanding these principles helps students grasp how energy is moved and utilized in refrigeration cycles, and the importance of maintaining optimal temperature differentials for cost-effective operation.