Expansion Devices in Refrigeration

In the vapor compression refrigeration system, the purpose of the expansion devices

• Increasing the liquid refrigerant pressure

• Reducing the liquid refrigerant pressure

• regulating flow to the evaporator

• Both A and B

• Both B and C

The most type of expansion device used in domestic refrigeration systems is the

• Automatic expansion valve

• Thermostatic expansion valve

• Capillary tube

• Float valve

• All of these

For capillary tube in the refrigeration system the evaporator flooding condition occurs when the

• Evaporator pressure drops and the capillary tube feed more refrigerant

• Evaporator pressure rises and the capillary tube doesn’t feed more refrigerant

• Compressor discharge pressure decreased

• Both A and B

• Both B and C

One of the disadvantages of capillary tubes is that they are ............ to changing load conditions

• adjustable

• not adjustable

• adaptable

• Both A and B

• Both B and C

Starving of evaporator followed by reduction cooling capacity occurs when

• There is a refrigerant leakage in the system

• The expansion valve is located at a higher elevation compared to condenser

• The inlet to the expansion valve is in two-phase region

• All of these

• None of these

For capillary tube in the refrigeration system the evaporator starving condition occurs when the

• Evaporator pressure rises and the capillary tube doesn’t feed more refrigerant

• Evaporator pressure drops and the capillary tube feed more refrigerant

• Condenser pressure increased

• Both A and B

• Both B and C

The function of automatic expansion valve is

• The degree of superheat of the suction gas leaving the evaporator

• Increasing the evaporator pressure

• Maintaining a constant evaporator pressure.

• The temperature in the condenser

• All of these

The pressure in a capillary tube decreases due to

• frictional resistance offered by the tube wall

• heat transfer from the tube

• acceleration of refrigerant in the tube

• Both A and C

• Both B and C

Which one the following is fixed opening type expansion device

• Thermostatic expansion device

• Automatic expansion device

• Capillary tube

• Both A and B

• Both B and C

flooding in evaporator occurs when

• Compressor delivers less than the capillary tube can handle

• Suction pressure of compressor decreases

• Load decrease

• All of these

• None of these