2 Refrigeration Systems and Components Free Online FlashCards

What does a vapor-compression refrigeration system do?

It transfers heat from a cooler space to warmer surroundings by circulating refrigerant through a sealed loop.

What are the compressor’s main functions?

It draws low-pressure vapor from the evaporator, compresses it to a higher pressure, and circulates refrigerant through the system.

What happens to refrigerant in the condenser?

It rejects heat to the surrounding air or water as hot, high-pressure vapor condenses into high-pressure liquid.

What does the metering device do to refrigerant?

It restricts flow from the high-pressure side to the low-pressure side. The pressure drop makes some liquid flash into vapor, creating a cold liquid-vapor mixture.

What happens in the evaporator?

It absorbs heat from the cooled space, causing low-pressure refrigerant to boil from a cold liquid-vapor mixture into vapor.

How does refrigerant pressure affect its boiling and condensing temperatures?

Lower pressure lets refrigerant boil at a lower temperature, while higher pressure lets it condense at a higher temperature.

How does a thermostat help control cooling?

It detects the refrigerated space’s temperature and commonly starts or stops the compressor in response to cooling demand.

Why does compression heat the refrigerant?

Compression raises the refrigerant’s temperature, allowing it to release heat to warmer surroundings at the condenser.

Why does a refrigerator condenser feel warm?

It rejects both the heat absorbed in the evaporator and the energy added by the compressor, so it is normal for the condenser to feel warm.

How does a capillary tube regulate refrigerant flow?

It is a narrow, fixed-length tube that provides a fixed restriction and does not actively adjust its opening as operating conditions change.

What does a thermostatic expansion valve (TXV) adjust?

It varies refrigerant flow to help maintain appropriate superheat at the evaporator outlet.

Does the evaporator create cold?

It does not create cold; it absorbs heat from the cooled space and carries that heat away in the refrigerant.