Refrigeration System

Question 1

Does refrigeration supply cold air or remove heat?

Answer 1

Refrigeration removes heat from a source

Question 2

Sensible Heat

Answer 2

Indicated Rise in temperature as heat is added

Question 3

Latent Heat

Answer 3

No indicated rise in temperature as heat is added

(Heat is being used for phase change)

Question 4

Radiation Heat Transfer

Answer 4

heat transfer via infared light and some visible lights

Question 5

Conduction Heat Transfer

Answer 5

Heat transfer from contact between adjacent molecules

Question 6

Convection Heat Transfer

Answer 6

Heat transfer from motion and mixing portions of a fluid

Question 7

Define a refrigerant ton

Answer 7

The amount of heat asorbed in melting one ton (2000) LBS of ice in 24 hours

Question 8

Characteristics of a refrigerant

Answer 8

• boils at low temperature
• could be toxic or flammable (most of these replaced with freon)
• could also cause ozone depletion

Question 9

How can pressure and temperature affect heat transfer

Answer 9

• Pressure increases then the amount of heat needed is more to raise temperature to a higher boiling point.

Question 10

Draw a refrigeration cycle

Answer 10

Compressor

Energy Addition

Heat Absorption Heat Rejection

Evaporator Condenser

Expansion valve or metering device

Question 11

Function of Heat Absorption

Answer 11

Heat transferred source to refrigerant turns it in to a vapor

Question 12

Function of Energy Addition

Answer 12

Compressor raises pressure and heat to be higher than the cooling medium

Question 13

Function of Heat Rejection

Answer 13

Heat is transfered via the condenser to a water system and taken away

Question 14

Function of Expansion

Answer 14

Expansion valve or metering device drops pressure and lowers boiling point of refrigeration to be able to remove heat from source

Question 15

Function of Evaporator

Answer 15

Transferrs heat from medium to be cooled to low pressure refrigerant

Question 16

Function of compressors

Answer 16

Adds energy to refrigerant to allow for heat transfer at the condenser

Question 17

Function of Condensers

Answer 17

Transfers heat from refrigerant to air or water cooling

Question 18

Function of Receivers

Answer 18

Stores refrigerant in higer capacity systems

Question 19

Function of Filter/ Drier

Answer 19

Removes particles and debris in systems

Question 20

Function of liquid line sight glass

Answer 20

Used to show bubbles which could indicate low refrigerant

Question 21

Function of expansion valves

Answer 21

Throttling device which lowers PSI and Temperature of refrigerant allowing it to remove more heat

Question 22

Are Refrigerants Flammable?

Answer 22

no

Question 23

Safety concerns with refrigerants Temperature/ Pressure

Answer 23

Could cause frostbite, heavier than air, line of fire if releasing a cap under pressure

Question 24

Safety Concerns for refrigerants “Toxic Fumes”

Answer 24

Some fumes are toxic and under extreme temperatures can become Hydrocloric and Hydroflouric Acid. Chill water x area

Question 25

Safety concerns “Environmental”

Answer 25

Detrimental to wildlife and people

Question 26

What is a BTU

Answer 26

The amount of heat required to raise 1 lb of water 1 degree