Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Turn Out > Refridgeration > Flashcards

Refridgeration Flashcards

1
Q

The low side of a vapor compression cycle contains the?

A

Evaporator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the primary unit of heat used in the United States

A

BTU British thermal unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which direction does heat flow

A

From warm to cold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In which component does refrigerant release or exhaust heat

A

The condenser

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Besides temperature what other fundamental variable can be changed to alter the boiling point of a substance

A

Pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where is the atmospheric pressure greater Miami or Leadville

A

Miami

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Besides conduction and convention what is another method heat is transferred from one substance to another

A

Radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What causes atmospheric pressure

A

The pressure or mass of the atmosphere pushing down on the earths surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Refrigeration cycles move heat from one location to another using what type of heat

A

Latent heat transfer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

When a refrigeration system moves heat does it release more less or the same amount of heat that it absorbs

A

More

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which term refers to liquid refrigerant super heated or sub cooling

A

Sub cooling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Is the refrigeration cycle that operates in the water fountain the seam is that in a large chiller

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What best identifies the nature of refrigerant going in and out of the metering device

A

Liquid in gas liquid mix out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

In normal operation does liquid refrigerant return to the compressor in the refrigerating machine

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How many thousand BTU per hour generate a ton of cooling capacity

A

12,000 BTU per hour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What best identifies the nature of the refrigerant going in and out of the condenser

A

Gas in liquid out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Compressors add heat to the refrigerant in two ways what are they

A

Heat of compression and motor heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Gaseous refrigerant heated above its boiling point is said to be

A

Super heated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the word used to describe the state of matter of gas heated just a little above its boiling point

A

Superheated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

True or false most of the heat transferred by the refrigerant in a vapor compression cycle is a latent heat

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Sub cooling occurs in which of the four parts of the refrigeration cycle

A

Condenser

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which has more enthalpy a pound of water at 32° or a pound of ice at 32°

A

A pound of water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What unit is enthalpy expressed in

A

Btu/lb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the primary hazards when working around refrigerant in an enclosed area

A

Suffocation and displacement of oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Refrigerant recovery cylinders are equipped with which safety devices

A

Fusible plug and pressure relief valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What gas is used to purge refrigerant lines during brazing

A

Nitrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What direction is refrigerant piping sloped

A

It is slightly sloped down in the direction of refrigerant flow

28
Q

What piping configuration keeps oil or liquid refrigerant from running back down the discharge line in the office cycle

A

S or inverted trap

29
Q

What type of fitting is not acceptable for copper refrigerant lines

A

Compression fittings

30
Q

If the temperature of a full refrigerant recovery cylinder is increased what happens to the pressure inside the cylinder

A

The pressure will rise

31
Q

Scientists have identified CFC &HCFC refrigerants as agents of __________Depletion in the upper atmosphere

A

Ozone

32
Q

A condensing unit contains which two of the four main refrigeration components

A

Condenser and compressor

33
Q

How does a suction or discharge line P-trap assist with the flow of oil

A

It builds up a pool of oil which partially blocks the pipe reducing the effective size of the pipe and causing oil to entrain with the refrigerant

34
Q

In which state does oil Best mix with refrigerant

A

Liquid

35
Q

Are liquid line solenoid valves directional, that is does it matter which side you connect the liquid line from the condenser and which side points to the metering device

A

Yes

36
Q

Brazing rod comes in the 0% 5% 15% in some higher percentages like 40% what metal is referred by the percentages

A

Silver

37
Q

What brazing rod requires a special paste flux when making copper to steel joints

A

40%

38
Q

When a flame is exposed to refrigerant gas what is produced

A

Acids

39
Q

What two forces act on oil movement in refrigeration systems

A

Gravity and refrigerant velocity

40
Q

What is an undesirable side effects of an undersized pipe in refrigerant piping

A

Too high of a velocity

41
Q

What is an undesirable affect of an oversize pipe in refrigerant piping

A

Too low of velocity allowing refrigerant and oil to separate

42
Q

What device is installed to prevent refrigerant migration to the evaporator in the off cycle

A

Liquid line solenoid valve

43
Q

What weight of tubing is commonly used in refrigeration installations

A

Type L

44
Q

What is cleaned out of copper tubing labeled ARC/OXY or med gas that is left in regular tubing

A

Manufacturing oils and waxes

45
Q

What can help fit up larger copper refrigeration fittings

A

Paraffin wax or soap

46
Q

One practice that helps larger tubing fittings fit up is

A

File away the lip on the outside of the pipe left over from the tubing cutters

47
Q

What is the purpose of pressurizing ARC tubing with dry nitrogen for shipping and storage

A

To keep oxygen out preventing oxidation

48
Q

Removing banks of pistons from operation to achieve a reduction in compressor capacity is a feature of which type of compressor

A

Reciprocating

49
Q

True or false compressors with unloaders are typically set up to start fully loaded

A

False

50
Q

If the compressor is fully unloaded and compressor operation still results in suction gas pressure below desired levels what is accessory may be installed to address the situation

A

Hot gas bypass

51
Q

What is the order of the state of refrigerant as it passes through the condenser in normal operation

A

Gas to saturated vapor to sub cool the liquid

52
Q

What can cause higher compressor head pressure’s

A

Debris in bedded in condenser coil’s or build up of dust on condenser coil’s

53
Q

The amount of heat rejected in the condenser is greater than or less than the amount of heat absorbed in the evaporator

A

Greater than

54
Q

What flower arrangement results in the most efficient heat transfer three hydronic heat exchanger or coil

A

Counter flow

55
Q

Excessively high temperature difference between the entering and leaving water of a condenser could indicate

A

Restricted water flow

56
Q

What type of condenser is typically found on smaller equipment

A

Double pipe

57
Q

What type of water condenser is typically found on larger equipment

A

Shell and tube

58
Q

What measure is taken to reduce the buildup of scale in cooling tower water loops

A

Chemical additive

59
Q

If a chilled water source is used to remove heat from the water cooled condenser what device might be installed to keep head pressure steady

A

Water regulating valve

60
Q

A once through water cooled condenser refers to an application which

A

City water passes through the condenser and then down the drain

61
Q

To keep condenser water from getting too cold contemporary cooling towers typically use what for leaving water temperature control

A

A variable frequency drive on the fan motor to modulate fan speed

62
Q

What measurement is taken to keep cooling tower sumps from freezing in the winter

A

Heat trace or receiving tank on the inside of the building

63
Q

Water levels in the sump of a cooling tower or the evaporative condenser are typically controlled by what

A

A float valve

64
Q

What advantages do water cooled condenser’s have over air cooled condenser’s

A

Lower condensing temperatures and pressure on the refrigerant side making compressor is more efficient

65
Q

What are the advantages of air cooled condensers over cooling tower systems

A

No seasonal changes in operation are needed

66
Q

The main problem with the air cooled condensers in some areas of the country like ours is

A

Cottonwood debris that blows through the air gets sucked into them

Turn Out (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions