Industrial Refrigeration Part A and B

Question 1

Heat always moves from a _____ temperature area to a ______ temperature area.

Answer 1

Heat always moves from a (Higher) temperature area to a (Lower) temperature area.

Higher to lower

Question 2

What heat type can be measure with a thermometer?

Answer 2

Sensible heat

Question 3

What is latent heat?

Answer 3

Latent heat is added or removed to change the state of the material.

Question 4

What the ____ increases, the boiling point increases too.

Answer 4

When the pressure increases, the boiling point increases too.

Question 5

NOTE
The low pressure side starts from the outlet of the metering device and continues as the refrigerant flows to the inlet of the compressor. The high-pressure side starts from the outlet of the compressor and continues as the refrigerant flows to the inlet of the metering device.

Whenever the compressor operates, these two pressures are established and maintained. As the two pressures are maintained, a low boiling temperature and high condensing temperature also maintained

Answer 5

.

Question 6

What is super heating?

Answer 6

The addition of heat to a vapour, which elevated the temperature higher then the boiling point.

Question 7

What is the function of the evaporator?

Answer 7

The refrigerant within the evaporator tubes absorb the heat from the refrigerated space.

The evaporator is considered the “cooling” component

Question 8

What is the purpose of the compressor in a refrigeration system?

Answer 8

The compressor maintains a low pressure in the evaporator and simultaneously maintains a high pressure in the condenser. It also keeps the circulation of the refrigerant going.

Question 9

What is the purpose of the condenser?

Answer 9

The condenser is located outside of the refrigerated space to reject heat from the circuit.

Question 10

What is the purpose of the metering device in a refrigeration system?

Answer 10

The Metering device throttles and regulates the flow of refrigerant and maintains the pressure difference between the evaporator and the condenser.

Question 11

Does the metering device receive liquid or vapour on its inlet?

Answer 11

It receives liquid, no vapour should ever enter the metering device.

Question 12

When liquid enters the metering device and flashes what are the percentages of liquid/vapour on the outlet?

Answer 12

Typically 75% liquid and 25% vapour.

Question 13

What are the three styles of compressors that can be used in the refrigeration process?

Answer 13

1. Hermetic reciprocating (un-serviceable)
2. Semi-Hermetic reciprocating (serviceable)
3. Open

Question 14

Is the boiling point high or low in the evaporator? And is the temperature cold, warm or hot?

Answer 14

The boiling point is low and the temperature is cold.

Question 15

What is a TXV

Answer 15

Thermal expansion valve

Question 16

What is the name of the pipe that connects the condenser to the high pressure receiver?

Answer 16

condensate drain line

Question 17

Which Part of a vapour compression refrigeration system will contain both high-pressure liquid and gas?

Answer 17

Condenser

Question 18

Why must the pressure of refrigerant be raised by the compressor?

Answer 18

To increase its boiling/ condensing temperature

Question 19

Heat energy moves within a liquid by?

Answer 19

Convection

Question 20

The temperature of the refrigerant is highest after the?

Answer 20

Compressor

Question 21

What refrigerant is used in a lithium bromide refrigeration system?

Answer 21

Water

Question 22

What are the 3 categories of insulating materials used to control thermal energy

(including temperature ranges)

Answer 22

-Cryogenic insulation
Below -101C
(-150F)

-Thermal insulation
-101C to +815C
(-150F to +1500F)

-Refractory insulation
Above +815C
(+1500F)