CRST Refrigeration Systems & Components

Question 1

What is the main function of the compressor in a refrigeration system?

Accepted Answer

Compress refrigerant vapor

Answer

The compressor is the 'heart' of a refrigeration system, responsible for increasing the pressure and temperature of the refrigerant vapor. This compression is crucial because it allows the refrigerant to then release its absorbed heat in the condenser. Without compression, the refrigerant wouldn't be able to effectively circulate and transfer heat, thus preventing cooling.

Question 2

What component removes heat from the refrigerant?

Accepted Answer

Evaporator

Answer

The evaporator is the component where the refrigerant absorbs heat from the space or substance being cooled. As the low-pressure liquid refrigerant enters the evaporator, it boils and changes into a vapor, drawing heat from its surroundings in the process. This heat absorption is the primary mechanism for cooling in a refrigeration system.

Question 3

What is the role of the condenser in a refrigeration system?

Accepted Answer

Reject heat and condense

Answer

The condenser's primary role is to reject the heat absorbed by the refrigerant from the cooled space to the ambient environment. In the condenser, the high-pressure, high-temperature refrigerant vapor cools down and changes back into a liquid state, releasing its latent heat. This condensation is essential for the refrigerant to be ready to absorb more heat in the evaporator.

Question 4

How does the expansion valve function?

Accepted Answer

Regulate flow and reduce pressure

Answer

The expansion valve, also known as a metering device, regulates the flow of liquid refrigerant into the evaporator. It also causes a significant pressure drop, which lowers the refrigerant's boiling point. This pressure reduction is critical for the refrigerant to readily absorb heat and evaporate in the evaporator, initiating the cooling cycle.

Question 5

Why is refrigerant important in a system?

Accepted Answer

Absorb and release heat

Answer

Refrigerant is the working fluid in a refrigeration system, vital for its ability to absorb heat at low temperatures and pressures, and then release that heat at higher temperatures and pressures. This phase change property (liquid to vapor and back) allows it to efficiently transfer thermal energy from one location to another. Without refrigerant, the system cannot achieve cooling.

(CRST) Certified Refrigeration Service Technician Practice Test

(CRST) Certified Refrigeration Service Technician Practice Test

CRST Refrigeration Systems & Components