[D2L] 104C Refrigeration Control Circuits

Question 1

What type of defrost do small, medium temperature refrigeration systems typically use?

Answer 1

off-cycle defrost

Question 2

Which temperature is more prominent(현저한) to oil return problems?

Answer 2

low temperature

Question 3

What is the most important factor with regards to piping design in low temperature applications?

1) piping velocity
2) compressor oil return
3) looks neat and tidy

Answer 3

compressor oil return

Question 4

When is an OFC(Oil Failure Control) used?

Answer 4

when a reciprocating compressor has a oil pump

Question 5

A crankcase heater helps reduce refrigerant migration and oil frothing on start up

Answer 5

True

Question 6

How is compressor short cycling reduced?

1) Pump-out system
2) compressor capacity control
3) Delay on break controls
4) all of the above

Answer 6

All of the above

Question 7

A CPR valve is a method of reducing compressor overloading by limiting the Max Suction pressure to the compressor.

Answer 7

True

Question 8

What does reducing superheat, and compressor head cooling accomplish?

1) reduce discharge temperature
2) reduce compression ratios
3) reduce discharge pressure
4) all of the above

Answer 8

All of the above