Objective 6,7,8& 9

What is the purpose of compressors in the refrigeration process?

• To change low-pressure saturated vapor into higher pressure, higher temperature super-heated vapor

• To remove moisture from the refrigerant

• To cool the refrigerant before it enters the compressor

• To increase the volume of the refrigerant

How does a screw compressor work?

• By using two intertwined screw rotors to compress the refrigerant

• By using a reciprocating motion to compress the refrigerant

• By using a piston to compress the refrigerant

• By using a centrifugal force to compress the refrigerant

What is the function of the slide valve in a screw compressor?

• To limit the compression ratio and provide compressor capacity control

• To regulate the temperature of the refrigerant

• To increase the speed of the compressor

• To control the flow of oil in the compressor

What type of lubrication system is used in smaller compressors?

• Splash lubrication system

• No lubrication system

• Pump lubrication system

• Combination of splash and pump feed

What is the purpose of an oil failure control (OFC) device?

• To regulate the temperature of the refrigerant

• To increase the speed of the compressor

• To interrupt the motor compressor control circuit when there is inadequate lubrication

• To control the flow of oil in the compressor

How does a reciprocating compressor operate?

• By using a scroll mechanism to compress the refrigerant

• By using a piston that moves up and down inside the cylinder

• By using a centrifugal force to compress the refrigerant

• By using two intertwined screw rotors to compress the refrigerant

What is the purpose of capacity control in a compression refrigeration system?

• To match the capacity of the compressor with the heat load requirement

• To cool the refrigerant before it enters the compressor

• To remove moisture from the refrigerant

• To increase the volume of the refrigerant

What are the two types of capacity control used with screw compressors?

• Pump lubrication system and splash lubrication system

• Piston and scroll mechanism

• Centrifugal force and reciprocating motion

• Slide valve and variable speed

How does a splash oil feed system work?

• It uses a scroll mechanism to compress the refrigerant

• It uses the motion of the crankshaft and connecting rods to splash crankcase oil inside the compressor casing

• It uses a reciprocating motion to compress the refrigerant

• It uses a centrifugal force to compress the refrigerant

What is the function of the male rotor in a screw compressor?

• To be the driving force rotor attached to the motor

• To compress the refrigerant between the lobes of the rotors

• To regulate the temperature of the refrigerant

• To control the flow of oil in the compressor