Unit 24 Refrigeration System Expansion Devices Flashcard

Front

What is the function of an expansion device in a refrigeration system?

Back

The function of an expansion device is to produce a reduction in the pressure on the liquid refrigerant, regulate the flow of refrigerant into the evaporator, and lower the boiling point of the refrigerant far enough below the temperature of the load to achieve the needed heat transfer rate.

Front

Where is the TXV sensing bulb typically mounted?

Back

The TXV sensing bulb is mounted on the suction line between the evaporator and the compressor.

Front

True or False: An automatic expansion valve uses a thermal bulb to help control the amount of refrigerant being fed into the evaporator.

Back

False.

Front

What is the linear motion of the pin or valve port piston of the electronic step-motor expansion valve?

Back

Front

True or False: AXVs are usually found on smaller equipment with somewhat constant evaporator loads.

Back

True.

Front

What does TXV stand for in refrigeration systems?

Back

TXV stands for Thermal Expansion Valve.

Front

What is the primary purpose of a thermal expansion valve (TXV)?

Back

The primary purpose of a TXV is to regulate the flow of refrigerant into the evaporator based on the cooling load.

Front

What is the difference between a TXV and an automatic expansion valve (AXV)?

Back

A TXV adjusts the refrigerant flow based on the evaporator's cooling load, while an AXV maintains a constant pressure in the evaporator regardless of the load.

Front

What happens to the refrigerant pressure as it passes through an expansion device?

Back

The refrigerant pressure decreases as it passes through an expansion device.

Front

What is the role of the thermal bulb in a TXV?

Back

The thermal bulb senses the temperature of the refrigerant and helps control the flow of refrigerant into the evaporator.