Basic on Refrigeration & Air Conditioning

Refrigeration System

The mechanism used for lowering or producing low temp. in a body or a space, whose temp. is already below the temp. of its surrounding, is called the refrigeration system.
Here the heat is being generally pumped from low level to the higher one & is rejected at high temp.

Refrigeration

The term refrigeration may be defined as the process of removing heat from a substance under controlled conditions.
It also includes the process of reducing heat & maintaining the temp. of a body below the general temp. of its surroundings.
In other words the refrigeration means a continued extraction of heat from a body whose temp is already below the temp. of its surroundings.

Major Applications

Food processing ,preservation & distribution.
Chemical & process industries.
Special applications such as cold treatment of metals , medical , construction etc.Comfort air conditioning.
Refrigerating system
Refrigerated system
Refrigerant – working fluid

The equipment used to maintain a lower temperature inside the system than its surroundings is known as refrigerating system & the working fluid used inside the system is known as refrigerant.

TYPES OF REFRIGERATORS

Air refrigerator
Vapour refrigerator

Unit of refrigerating capacity

The rate of heat absorbed from a body to be cooled is called refrigerating effect.
Refrigerating effect: It is the amount of heat energy removed per unit time from the space to be cooled by the refrigeration process. It is expressed in kw or kJ/s. It is also called capacity of a refrigerator.
The main unit of refrigeration is tones of refrigeration (TR).
It is the rate at which the heat is removed from one U.S tone of water at 0 d.c to ice at 0 d.c in 24 hrs.
The rate of heat absorbed by the system from the body to be cooled, equivalent to the latent heat of fusion on 1ton of ice from and at 0 d.c in 24 hours is called one ton refrigeration.
One ton of refrigeration is the rate of heat absorbed by the system from the body to be cooled ,equivalent to the latent heat of fusion of one ton of ice, from and at zero degree Celsius in 24 hours.In general 1 ton refrigeration is equivalent to 3.5167 kJ of heat removal per second.

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