Chapter 115- Compression Refridgeration Systems Flashcards Preview

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Flashcards in Chapter 115- Compression Refridgeration Systems Deck (15):
1

Refrigeration may be broadly defined as

A controlled process of cooling or removing heat from a substance and then maintaining the temperature of that substance below that of the surrounding temperatures

2

Closed cycle refrigeration systems may be divided into two classes according to the method used to raise the pressure of the refrigerant after it leaves the compressor

The compression system
The adsorption system

3

Most modern refrigeration systems use the principle of absorbing heat by the rapid evaporation or boiling of a working medium. This process is called

Mechanical refrigeration

4

A simple closed cycle compression refrigeration system is composed of five principle parts which are called

Evaporator
Compressor
Condenser
Liquid refrigerant control or regulating valve
Liquid receiver

5

What is latent heat

Energy required to move a substance from solid to liquid, liquid to gas etc

6

What is sensible heat

Heat that changes the temperature of a substance

7

What cools the refrigerant in a refrigator

As the compressor increases the pressure the working fluid changes from a vapour to a liquid. When the liquid enters the low pressure area energy is required for it to transf back to a vapour. The working fluid takes energy from its surroundings in order to to move from a liquid to a vapour state thus cooling its surroundings

8

The heat added to the refrigerant is _________ to the heat removed from the refrigerant

Equal

9

In the low pressure side the temperature is

Low

10

In the high pressure side the refrigerant is

High tempurature

11

A direct system is

One in which the evaporator is in direct contact with the space being refrigerated

12

An indirect refrigeration system is one that

Is one that contains a separate working fluid, such as salt water, that is cooled and then transported to the area being cooled.

13

The first consideration when picking a working fluid for a refrigeration unit is

The temperature required for the medium to be cooled

14

A general rule regarding the working fluid of a refrigeration system

The evaporation temperature should be between 5 and 10 degrees Celsius lower than that of the cooled medium

15

A a general rule when dealing with the condensing temperature with the vapour state of your working fluid

It should be approximately 15-20 degrees Celsius when a water cooled condenser is used