12. ACR-104 UNIT 23 END OF UNIT TEST

If the compression ratio of a system with a reciprocating compressor decreases, the amount of refrigerant pumped by the compressor ____.

• will increase

• will decrease

• will remain the same

• cannot be determined

Most of the heat energy in the suction vapor entering the compressor is ____.

• subcooled from the condenser

• superheated from the condenser

• superheated from the evaporator

• subcooled from the evaporator

The temperature of the compressed gas leaving the compressor can best be described as ____.

• cold

• cool

• warm

• very warm

The screw compressor is used primarily in ____.

• large commercial and industrial systems

• residential air conditioning

• small commercial refrigeration units

• domestic refrigerators

Rotary compressors are used primarily in ____.

• large industrial refrigeration and air conditioning systems

• residential and light commercial air-conditioning

• small commercial refrigeration units

• high volume residential refrigeration

The clearance volume of a compressor cylinder is the ____.

• amount of refrigerant vapor the compressor cylinder will hold during each stroke

• volume by which the compressor is rated

• volume of the space between the bottom of the valve plate and the top of the piston at the top of the stroke

• total volume of the cylinder when the piston is at the bottom dead-center

The discus valve design is more efficient than a flapper valve design because _____.

• it allows a compressor design with less clearance volume

• it operates with less spring tension

• the amount of expanded vapor in the cylinder is greater

• it will not allow liquid refrigerant in the cylinder

Liquid entering the compression chamber of a reciprocating compressor can lead to _____.

• damaged valves

• damaged piston rings

• damaged expansion valves

• Both a and b.

Rotary compressors have pistons that rotate inside the cylinders.

• True

• False

The rotary screw compressor uses an open motor instead of the hermetic design.

• True

• False