Chapter 117- Heat Exchangers For Refridgeration Systems Flashcards

1
Q

Define medium

A

The medium is another term for the substance your working with, a cooling medium could be a refrigerant, or the medium Being cooled would be air

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2
Q

Two types of heat exchangers

A

Dry or direct

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3
Q

Advantage of a dry evaporator over a flooded evaporator

A

Size

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4
Q

What’s the advantage of a plate heat exchanger

A

Increased surface area

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5
Q

Three types of condesors

A

Air cooled
Water cooled
Evaporative

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6
Q

Condenser is used to remove three types of heat

A

Heat of compression
Sensible heat
Latent heat

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7
Q

Three types of water cooled condenser

A

Double tube
Shell and coil
Shell and tube

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8
Q

Evaporative condensers use both _______ and____ to provide cooling

A

Air and water

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9
Q

Name two types of operating classification of refrigeration units

A

Dry or direct expansion evaporator units

Flooded evaporator

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10
Q

Define a dry evaporator

A

A dry evaporator only has a small amount of refrigerant at any given time. The amount admitted equals the amount that leaves the evaporator

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11
Q

Define a flooded evaporator

A

A flooded evaporator is completely filled with refrigerant at any given time

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12
Q

Advantage of a flooded evaporator

A

High rate of heat transfer

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13
Q

Disadvantage of a flooded evaporator

A

Requires more refrigerant

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14
Q

Four different types of evaporator a

A

Bare tube
Plate surface
Finned tube
Shell and tube

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15
Q

Different name for a finned tube evaporator

A

Blast coil

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16
Q

Three different types of condensers

A

Air cooled
Water cooled
Evaporative

17
Q

What must be done to a large air cooled condenser

A

Must be taken outside in order to provide proper heat transfer

18
Q

Three types of water cooled condensers

A

Double tube
Shell and coil
Shell and tube

19
Q

Define a double tube condenser

A

A small tube contained concentrically within a larger tube

20
Q

Shell and coil condenser Define it

A

The shell and coil condenser consists of a horizontal or vertical steel shel which contains a coiled tube, either bare or finned through which cooling water circulates. Hot vapour enters the top, transfers its heat to the cooling medium and then collects in the bottom of the shell as a liquid

21
Q

She’ll and tube condenser define it

A

Same idea as the shell and coil, but with straight tubes and water boxes at either end

22
Q

Evaporative condensers define it

A

Use both air and water to provide cooling in order to condense the refrigerant vapour

23
Q

The main benefit of a evaporating condenser

A

A saving of 80- 90 percent in water consumption may be achieved ideal fr area where water is in high demand

24
Q

What protects a condenser from freezing during cold month while not operational

A

Louvers in the air vents close to prevent air movement

25
Q

Defective condenser operation may result from

A

Dirty cooling water

26
Q

Why must a condenser be vented periodically

A

To remove non condensable gasses

27
Q

If cooling war contains scale forming salts

A

They may build up on your tubes lowering efficiency

28
Q

What type of evaporator only contains a small amount of liquid at any given time

A

Dry or expansion

29
Q

What type of evaporator can be easily cleaned and Eurostar manually without interrupting the cooling process

A

Plate surface

30
Q

Which type of condenser uses the least amount of cooling water

A

Evaporative condenser

31
Q

What is the purpose of the condenser

A

To remove heat from the refrigerant

32
Q

Two disadvantages of a flooded evaporator

A

Requires more refrigerant

Requires more space

33
Q

What types of actuated controls control a start stop compressor 3

A

Temperature
Humidity
Pressure