CARO Refrigeration Cycle Fundamentals 2

Question 1

Under normal operating conditions, in what state should refrigerant leave the evaporator?

Accepted Answer

Slightly superheated vapor

Answer

A small amount of superheat ensures all liquid has boiled off before the vapor reaches the compressor.

Question 2

What type of heat does refrigerant primarily absorb as it boils in the evaporator?

Accepted Answer

Latent heat of vaporization

Answer

Boiling is a change of state, so most of the heat absorbed is latent heat of vaporization.

Question 3

If the pressure in an evaporator is lowered, what happens to the refrigerant's saturation (boiling) temperature?

Accepted Answer

It drops

Answer

Saturation temperature is directly tied to pressure, so lower pressure means a lower boiling point.

Question 4

How is liquid subcooling at the condenser outlet calculated?

Accepted Answer

Saturated condensing temperature minus actual liquid line temperature

Answer

Subcooling is how far the liquid has been cooled below its saturation temperature at condensing pressure.

Question 5

Refrigerant leaving the compressor discharge is best described as what?

Accepted Answer

High-pressure, high-temperature superheated vapor

Answer

Compression raises both pressure and temperature, leaving the vapor well superheated.

CARO - Certified Assistant Refrigeration Operator Practice Test