#1
Which of the following refrigerants has a low global warming potential (GWP)?
R-290
ExplanationR-290 has a low global warming potential.
#2
What is the purpose of a compressor in a commercial refrigeration rack system?
To pump refrigerant through the system
ExplanationThe compressor's role is to circulate refrigerant.
#3
What is the function of an evaporator in a refrigeration rack system?
To absorb heat from the refrigerated space
ExplanationEvaporator absorbs heat from the space.
#4
Which type of refrigeration system is commonly used in large supermarkets and grocery stores?
Direct expansion system
ExplanationDirect expansion systems are common in supermarkets.
#5
What is the primary refrigerant used in most supermarket refrigeration systems?
R-404A
ExplanationR-404A is the primary refrigerant in supermarkets.
#6
Which component of a refrigeration rack system is responsible for controlling the flow of refrigerant into the evaporator?
Expansion valve
ExplanationExpansion valve controls refrigerant flow.
#7
Which component of a refrigeration rack system is responsible for condensing the refrigerant from a high-pressure vapor to a high-pressure liquid?
Condenser
ExplanationThe condenser converts high-pressure vapor to liquid.
#8
What does the term 'floating head pressure' refer to in a refrigeration rack system?
A method of adjusting the head pressure based on ambient conditions
ExplanationFloating head pressure adjusts based on ambient conditions.
#9
What is the purpose of an accumulator in a refrigeration rack system?
To store excess refrigerant during low load conditions
ExplanationAccumulator stores excess refrigerant.
#10
Which of the following is a common method for defrosting evaporator coils in a commercial refrigeration rack system?
Hot gas defrost
ExplanationHot gas defrost is commonly used.
#11
What is the purpose of a crankcase heater in a refrigeration rack system?
To heat the compressor oil and prevent it from solidifying
ExplanationCrankcase heater prevents oil solidification.
#12
What does the term 'hot gas bypass' refer to in a refrigeration system?
A technique for regulating the compressor capacity
ExplanationHot gas bypass regulates compressor capacity.
#13
In a cascade refrigeration system, what is the primary purpose of the secondary refrigeration loop?
To provide cooling to a lower temperature range
ExplanationSecondary loop cools to lower temperature range.
#14
What is the purpose of a receiver in a refrigeration rack system?
To store excess refrigerant during low load conditions
ExplanationReceiver stores excess refrigerant.
#15
Which of the following is a common issue associated with commercial refrigeration rack systems during low ambient temperature conditions?
High head pressure
ExplanationLow ambient temps can cause high head pressure.
#16
What is the purpose of an oil separator in a refrigeration rack system?
To remove oil from the refrigerant
ExplanationOil separator removes oil from refrigerant.
#17
What is the purpose of a desuperheater in a refrigeration rack system?
To cool the refrigerant vapor before it enters the condenser
ExplanationDesuperheater cools refrigerant vapor before condenser.