Chapter - 113,114,115

Question 1

What is the saturation temperature of water and what is the atmospheric temperature?

Answer 1

100*C

101.325 kPa

Question 2

In a closed vessel, the boiling point of water and the condensing point of its vapour can be raised by…

Answer 2

Increasing the pressure in the vessel, and also lowered by decreasing the pressure

Question 3

Definition of: Sensible heat

Answer 3

The heat removed from the substance

Question 4

Definition of: Latent heat

Answer 4

The heat absorbed by the refrigerant

Question 5

What is 1 degree Celsius equal to in Fahrenheit?

Answer 5

1.8 degrees Fahrenheit

Question 6

Definition of: Capacity of a Refrigeration System

Answer 6

Capacity of any Refrigeration system is the rate at which it will remove heat from the refrigerated medium.

Question 7

Which system of measurement is Fahrenheit, Tons, Btu, and pounds (lbs)?

Which system of measurement is Celsius, Joules, Kilojoules, Kilowatts, Tonnes, and Kilograms?

Answer 7

• Imperial

- Metric

Question 8

A metric tonne of refrigeration is approximately _____ greater than an imperial ton of refrigeration.

• 30%
• 15%
• 85%
• 10%

Answer 8

10%

Question 9

The rate at which a system will remove heat from the refrigerated medium is defined as

Answer 9

Net Refrigeration Effect

Question 10

Definition of: Coefficient of Performance (COP)

Answer 10

Is the ratio of heat absorbed from the refrigerated medium by the evaporator to the amount of energy used to drive the compressor.

Question 11

Definition of: Compression Ratio

Answer 11

Is the clearance volume plus the piston displacement divided by the clearance volume.

Question 12

Name and describe the groups of refrigerants

Answer 12

Groups A1, A2, A3 are non-toxic but flammable

Groups B1, B2, are highly-toxic but nonflammable

Group B3 is highly-toxic and highly flammable

Question 13

Thermodynamic properties of refrigerants are…

Answer 13

The properties that directly affect the movement of heat

Question 14

EXAM QUESTION

The saturation temperature (boiling temperature) of a liquid in a closed vessel can be raised or lowered by…

Answer 14

Raising or lowering the pressure in the closed vessel

Question 15

Define miscibility

Answer 15

The ability of a refrigerant to be dissolved

Question 16

What is leakage tendency

Answer 16

The bigger the mass, the harder it is to escape small openings

Question 17

EXAM QUESTION

What are two reasons moisture she be avoided?

Answer 17

1- it will cause ice to form between the expansion valves

2- may cause acid formation resulting in corrosion

Question 18

What are the five parts of a closed type refrigerator?

Answer 18

Expansion valve 
Evaporator
Compressor
Condenser
Receiver

Question 19

EXAM QUESTION

What is another term for a direct refrigeration system?

Answer 19

Direct expansion systems

Question 20

What is the Difference between a direct system and an indirect system?

Answer 20

The evaporator in a direct system is inside the refrigerated area

Question 21

What is the role of an economizer?

Answer 21

It controls the amount of refrigerant flowing from the condenser to the evaporator

Question 22

What are the two parts of an economizer?

Answer 22

Upper and lower

Question 23

What refrigeration unit uses an economizer?

Answer 23

Centrifugal unit

Question 24

What are the three types of compressors

Answer 24

Reciprocating
Rotary
Centrifugal

Question 25

Explain a reciprocating compressor

Answer 25

It is very similar to a piston, which has two strokes, a suction and discharge stroke

Question 26

What are the two types of suction and discharge valves

Answer 26

Flexible reed and none flexible