Refrigeration

Question 1

Gas plant refrigeration uses what type of refrigerant

Answer 1

Propane

Question 2

Industrial liquid over feed systems use what type of refrigerant

Answer 2

Ammonia

Question 3

Matter is made up of what three molecules

Answer 3

Gasses
Liquids
And solids

Question 4

Define radiation

Answer 4

Radiation is a vaccume a heat transfer by electro magnetic waves

Warm objects radiate more heat than colder ones with the overall effect that cold objects gain more heat by radiation than warm objects

Question 5

Convection is

Answer 5

Heat transfer by moving matter.

When heated a fluid decreases in density, and the warm fluid that is high density pushes the warm fluid upwards

Question 6

Define latent heat

Answer 6

It is added or removed heat that pulls the molecule apart (ie ice melting)

Question 7

At what point does water turn into steam

Answer 7

Once it reaches 100c (212f)

Question 8

What are the two types of heat

Answer 8

Latent heat

Sensible heat

Question 9

Define sensible heat

Answer 9

can be measured and is the measure of vibration rate of molecules

Question 10

Define energy

Answer 10

The capacity to do work and may consist as

potential

Or

Kinetic

Question 11

Potential energy means what

Answer 11

Means that it is at rest and capable of doing work

Question 12

What are the typo main types of energy conversion

Answer 12

Electrical converted to mechanical

Mechanical converted to heat

Question 13

A liquid does what as it boils

Answer 13

Obsorbs heat

Question 14

A vapour does what as it condensates

Answer 14

Releases heat

Question 15

The quality of heat required to completely vapourize one Kilo of liquid(at boiling temp is called

Answer 15

Latent heat of vaporization

Reverse the process and you have

Latent heat of condensation

Question 16

What temperature does propane boil at

Answer 16

-42*c under the pressure of one atmosphere

Question 17

What temperature does pure ammonia boil at

Answer 17

-33*c under the pressure of one atmosphere

Question 18

The low pressure side of a refrigeration cycle starts where

Answer 18

From the outlet of the metering device and continues as the refrigerant flows to the inlet of the compressor

Question 19

The high pressure side of a refrigeration cycle stats where

Answer 19

From the outlet of the compressor and continues as the refrigerant flows to the inlet of the metering device

Question 20

Circulating refrigerant has four major processes

They are. in this order

Answer 20

Condensation
expansion
evaporation
compression

Question 21

What is the main purpose of the compressor in the refrigeration system

Answer 21

The compressor circulates and maintains a low pressure in the evaporator

Simultaneously it maintains a high pressure in the condenser

Question 22

What is the most common compressor in refrigeration

Answer 22

Reciprocating compressor

Question 23

What is the main purpose of the condenser in the refrigeration system

Answer 23

Reject heat from the circuit

Question 24

What is the main purpose of the metering device in the refrigeration system

Answer 24

Throttles and regulates the flow of refrigerant, also maintains the pressure difference between evaporator and condenser

Question 25

Aside from oil what is another substance that compressors should never pump

Answer 25

Liquid refrigerant as it resists compression

Question 26

What two reciprocating compressors are generally used in refrigeration

Answer 26

Screw Centrifugal

Question 27

The temperature above the condensing or boiling temperature of the refrigerant is called

Answer 27

Supper heat

Question 27

What heat transfers by moving matter, separating one from the other hirer on too colder on the bottom

Answer 27

Convection

Question 28

What transfer is caused by physical contact

Answer 28

Conduction

Question 29

The greatest heat transfer in a refrigeration system occurs in the Evaporator Or Condenser

Answer 29

Evaporator takes in mor BTUs than condenser can give off

Question 30

Liquid overfeed at the evaporator results in a mixture of liquid and gaseous refrigerant leaving the evaporator. What is used to prevent the liquid from entering the compressor suction

Answer 30

A low pressure receiver Liquid settles on the bottom while compressor suction suck the vapour from the top

Question 31

What effect does lowering the boiling point have on a liquid

Answer 31

Lowers the boiling point

Question 32

Why is it important refrigerant has a low boiling point

Answer 32

Lower boiling point means it can reach a lower pressure

Question 34

in the flooded system, the brine tubes are immersed

Answer 34

liquid refrigerant

Question 35

what does liquid-feed mean?

Answer 35

low pressure refrigerant is stored in a tank where is can be pumped where it can be pumped through evaporators again without having to go through an entire compression cycle

Question 36

why is liquid overfeed system commonly used in industrial applications

Answer 36

It can have multiple evaporators for one system

Question 37

what insulation category does Cellular glass fall into

Answer 37

Cryogenic

Question 38

what insulation category does fiberglass, rock-wool, and Vermiculite fall into

Answer 38

Thermal

Question 39

what insulation category do bricks and Gunnite mixture fall into

Answer 39

Refaractory

Question 40

ammonia flooded systems require an oil separator because

Answer 40

the oil does not return to the compressor

Question 41

liquid levels in a liquid overfeed low pressure receiver is monitored/controlled by

Answer 41

float switch

Question 42

lithium bromide (absorption) refrigerant uses ___________energy to produce the refrigerant effect

Answer 42

Heat

Question 43

what is used as the refrigerant in the lithium bromide absorption system

Answer 43

water

Question 44

what shut down cycle must a chiller run through to prevent crystallization

Answer 44

dilution cycle

Question 45

in an abortion system the heat ex changer serves what vital function

Answer 45

heats diluted solution and cools the concentrated solution

Question 46

the metering device on a compression refrigeration system can be what three devices

Answer 46

capillary tube, fixed orifice, or a thermostatically controlled expansion valve.

Question 47

boiling temp of a liquid, and condensing temp of a vapour can be at the same temperature as long as

Answer 47

pressure exerted on the fluid is the same

Question 48

as refrigerant turns into a vapor it absorbs what kind of heat

Answer 48

latent heat of vaporization

Question 49

when refrigerant condenses into a liquid the vapor rejects what type of heat

Answer 49

latent heat of condensation

Question 50

1 BTU = The amount of heat required to

Answer 50

raise 1 LB of H2O 1*F

Question 51

The lower pressure side of a metering device =

Answer 51

95%liquid 5% gas

Question 52

if pressure on water was lowered water would boil at a higher or lower temperature

Answer 52

lower temperature

Question 53

condenser pressure is controlled by

Answer 53

condensing capacity

Question 54

what is a heat exchange that draws heat into the vapor compression cycle

Answer 54

the Evaporator draws heat into the vapor compression cycle

Question 55

systems are designed to minimize or illuminate pressure through the

Answer 55

evaporator

Question 56

what is the purpose of the liquid line dryer system

Answer 56

removes small dirt particles, moisture, and acid

Question 57

what two things must a refrigerant do in low pressure, low temperature

Answer 57

absorb heat, evaporate (boil),

Question 58

in a refrigeration system, pressure on the low side is controlled by

Answer 58

compressor capacity

Question 59

in a refrigeration system, pressure on the high side is controlled by

Answer 59

condenser capacity

Question 60

name a heat exchange used in vapor compression refrigeration systems

Answer 60

shell and tube

Question 61

in which component is thermal energy absorbed by the refrigerant

Answer 61

evaporator

Question 62

what is the name for heat energy that causes temperature change

Answer 62

sensible heat

Question 63

in which component is refrigerant de-super heated, condensed and sub-cooled?

Answer 63

conensor

Question 64

what effect does the compressor have on the boiling/condensing temperature of the refrigerant

Answer 64

raises the boiling point

Question 65

what is the refrigerant used in lithium bromide Chillers

Answer 65

water

Question 66

what effect does the pressure decrease have on the boiling point of a liquid

Answer 66

it Decreases

Question 67

what id the purpose of a compressor in a refrigeration system

Answer 67

create low pressure in the evaporator, high pressure in the confessor

Question 68

why must pressure be raised before sending refrigerant to the condenser

Answer 68

to raise the condensing point so gas can become liquid

Question 69

what happens to refrigerant in the evaporator

Answer 69

heat energy is absorbed and it changes into a gas

Question 70

what is an auto purge used for

Answer 70

to vent non condescension gas from a refrigeration system

Question 71

what is a liquid overfeed system

Answer 71

an excess of liquid is supplied to the evaporator

Question 72

what type of condenser uses air flow and water evaporation

Answer 72

evaporator

Question 73

what is a hermetically sealed compressor

Answer 73

its a non serviceable vessel that holds the compressor, compressor driver, oil and refrigerant, and requires no shaft seal for compressor

Question 74

what is the upside to liquid over feed

Answer 74

they can use multiple evaporators for multiple different temperature applications