Refrigeration Systems Quiz

What happens if lithium bromide crystallizes in an absorption system?

• It enhances cooling performance

• It shuts down the system

• It increases heat absorption

• It turns into a refrigerant

In an absorption system, the generator’s primary role is to:

• Remove moisture from the refrigerant

• Separate the refrigerant from the absorbent

• Act as a storage for the refrigerant

• Heat the cooling water

Why are cascade refrigeration systems used in ultra-low temperature applications?

• They provide a high cooling capacity in a single-stage

• They use a combination of refrigerants to achieve extremely low temperatures

• They rely only on natural refrigerants

• They operate at higher pressures than other systems

What is the purpose of a cascade heat exchanger in a multi-stage system?

• To store refrigerant

• To transfer heat between refrigerant circuits

• To increase compression efficiency

• To remove contaminants from the refrigerant

A two-stage cascade system requires:

• Two separate refrigerant circuits

• A single compressor with a higher displacement

• A refrigerant mixture with a single boiling point

• A liquid injection cooling method

Which component in a cascade system ensures refrigerants do not mix between stages?

• Condenser

• Expansion valve

• Heat exchanger

• Oil separator

A transcritical cascade system uses CO 2 as:

• A primary refrigerant

• A secondary refrigerant

• A moisture control agent

• A lubricant for the compressor

You are troubleshooting an ultra-low refrigeration system, and the unit is not reaching the set temperature. The power supply is normal, and there are no leaks. What should you check next?

• Condenser coil cleanliness

• Refrigerant oil type

• Thermostatic expansion valve (TXV) calibration

• Check valve alignment

A customer reports that their absorption chiller is shutting down frequently. Upon inspection, you find crystallized lithium bromide. What should you do?

• Increase the pressure in the system

• Heat the absorber to break down crystals

• Replace the generator

• Flush the system with water

A cascade refrigeration system is running but showing a capacity drop. You suspect a plugged condenser tube. How should you proceed?

• Increase the refrigerant charge

• Perform an acid cleaning of the condenser

• Bypass the condenser and check system performance

• Increase system pressure