RSES Refrigeration Fundamentals & System Components 5

Question 1

The refrigerating effect of a system is defined as:

Accepted Answer

Heat absorbed per pound of refrigerant in the evaporator

Answer

Refrigerating effect (RE) = h_evaporator_out - h_evaporator_in, representing the heat absorbed by the refrigerant per unit mass in the evaporator.

Question 2

Which component in a refrigeration system is responsible for changing high-pressure liquid refrigerant to a low-pressure liquid/vapor mixture?

Accepted Answer

Metering device (expansion valve or orifice)

Answer

The metering device (TXV, fixed orifice, or capillary tube) creates a pressure drop that flashes some liquid to vapor, lowering refrigerant temperature.

Question 3

When checking system superheat at the evaporator outlet, a technician finds it is much higher than the TXV setpoint. The most likely cause is:

Accepted Answer

TXV restricted or underfeeding the evaporator

Answer

A restricted or underfeeding TXV allows less refrigerant into the evaporator, causing the refrigerant to become highly superheated before leaving the coil.

Question 4

In a two-stage refrigeration system, the economizer (intercooler) is used to:

Accepted Answer

Cool the discharge gas from the low-stage compressor and subcool liquid before the low-side expansion device

Answer

The intercooler cools the low-stage discharge gas (reducing high-stage work) and subcools liquid refrigerant, improving overall system efficiency.

Question 5

The purpose of a liquid line solenoid valve in a refrigeration system is to:

Accepted Answer

Stop refrigerant flow to the evaporator when the system is off or on demand

Answer

A liquid line solenoid valve is an electrically operated on/off valve that stops refrigerant flow to prevent evaporator flooding or pump-down the system.

(RSES) Refrigeration Service Engineers Society Certification Practice Test

(RSES) Refrigeration Service Engineers Society Certification Practice Test

RSES Refrigeration Fundamentals & System Components 5