ACR-104 Unit 23 Compressors (CRF)

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

• will remain the same

• will increase

• will decrease

• cannot be determined

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

• subcooled from the condenser

• subcooled from the evaporator

• superheated from the condenser

• superheated from the evaporator

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

• cold

• warm

• very warm

• cool

The screw compressor is used primarily in _____.

• large commercial and industrial systems

• small commercial refrigeration units

• domestic refrigerators

• residential air conditioning

Rotary compressors are used primarily in _____.

• large industrial refrigeration and air conditioning systems

• small commercial refrigeration units

• residential and light commercial air-conditioning

• high volume residential refrigeration

The clearance volume of a compressor cylinder is the _____.

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

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

• volume by which the compressor is rated

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

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

• the amount of expanded vapor in the cylinder is greater

• it operates with less spring tension

• it will not allow liquid refrigerant in the cylinder

• it allows compressor design with less clearance

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

• damaged expansion valves

• damaged valves

• damaged piston rings

• damaged valves and damaged expansion valves

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