CARO Refrigeration System Components 2

Question 1

In an ammonia system, what is the primary function of the high-pressure receiver?

Accepted Answer

Store liquid refrigerant and absorb fluctuations in system charge

Answer

The high-pressure receiver stores condensed liquid and buffers charge changes as load varies.

Question 2

Which compressor type uses two meshing helical rotors to compress refrigerant vapor?

Accepted Answer

Rotary screw compressor

Answer

A rotary screw compressor traps and compresses gas between intermeshing male and female rotors.

Question 3

What device on a screw compressor is used to vary capacity by changing the effective length of the rotors?

Accepted Answer

Slide valve

Answer

The slide valve moves to recirculate gas back to suction, reducing the effective compression length and capacity.

Question 4

In an evaporative condenser, how is heat primarily rejected from the refrigerant?

Accepted Answer

By evaporation of water sprayed over the coil while air is drawn through

Answer

Evaporative condensers reject heat mainly through the latent heat of water evaporating off the coil surface.

Question 5

What is the purpose of an oil separator installed in the compressor discharge line?

Accepted Answer

Remove oil from discharge gas and return it to the compressor

Answer

The oil separator captures oil carried over in discharge gas so it does not foul condensers and evaporators.

CARO - Certified Assistant Refrigeration Operator Practice Test