Embed Size (px)
DESCRIPTION
Refrigerator is one of the most important equipment of our daily life. let's see how it's works.
Citation preview
SEMINAR ON “VAPOUR COMPRESSION REFRIGERATION”
GUIDED BY:- PREPARED BY:-Mr. Devendra Bhandari Ujjwal Nautiyal B.Tech(ME) II sem 1014366(38)
Refrigeration
Vapour Compression Refrigeration
Refrigeration is a process of removal of heat from a substance at a temperature lower than the surrounding with the aid of external work.
In a refrigeration system, the rate at which the heat is absorbed in a cycle from the interior space to be cooled is called Refrigerating Effect.
Refrigeration
*Refrigerant
*In a refrigerator, a medium called Refrigerant continuously extracts the heat from the refrigerator which is to be kept cool at temperatures less than the atmosphere & finally rejects to it.
*Refrigerant acts as a heat exchange medium.
*e.g.- Ammonia, Freon, Methyl Chloride, Carbon dioxide, Isobutane.
Unit of Refrigeration & Ice making CapacityThe capacity of a refrigeration system is expressed
in tons of refrigeration which is the unit of refrigeration.
A ton of refrigeration is the quantity of heat absorbed in order to form one ton of ice in 24 hours when the initial temperature of water is 0°c.
1 Ton of Refrigeration = 210 kJ/min = 3.5kWIce making capacity is the capacity of the
refrigerating system to make ice beginning from water to solid.
S.I. unit of ice making capacity is kg/hr.
Coefficient of Performance
The coefficient of performance(briefly written as C.O.P.) is the ratio of desired effect to the work input.
Mathematically,
(C.O.P.)refrigerator = Desired effect = Q2____
Work Input Q1-Q2
T1=Tsurr
Source T1
T2<Tsurr
Sink T2
R Work Input,W=Q1-Q2
Heat Absorbed, Q2
Heat Rejected, Q1
Refrigerator is a reversed heat engine.It extracts Q2 amount of heat from sink & releases Q1 amount of heat to source.Input—Work(Q1-Q2)Output– Heat
Refrigerator
PARTS OF REFRIGERATOR
Parts of Refrigerator
Evaporator Compressor Condenser Expansion Valve
Types of Refrigeration System
Refrigeration System
Vapour Compression Refrigeration System
Vapour Absorption Refrigeration System
11
Type of Refrigeration
Vapour Compression Refrigeration
Ref ri gerat ion
Refrigeration cycle
Condenser
Evaporator
High Pressure
Side
Low Pressure
Side
CompressorExpansion Device
1 2
3
4
12
Type of Refrigeration
Vapour Compression Refrigeration
/Refr iger ation
Refrigeration cycle
Low pressure liquid refrigerant in evaporator absorbs heat and changes to a gas
Condenser
Evaporator
High Pressure
Side
Low Pressure
Side
CompressorExpansion Device
1 2
3
4
13
Type of Refrigeration
Vapour Compression Refrigeration
Ref ri gerat ion
Refrigeration cycle
The superheated vapour enters the compressor where its pressure is raised
Condenser
Evaporator
High Pressure
Side
Low Pressure
Side
CompressorExpansion Device
1 2
3
4
14
Type of Refrigeration
Vapour Compression Refrigeration
Ref ri gerat ion
Refrigeration cycle
The high pressure superheated gas is cooled in several stages in the condenser
Condenser
Evaporator
High Pressure
Side
Low Pressure
Side
CompressorExpansion Device
1 2
3
4
15
Type of Refrigeration
Vapour Compression Refrigeration
Ref ri gerat ion
Refrigeration cycle
Liquid passes through expansion device, which reduces its pressure and controls the flow into the evaporator
Condenser
Evaporator
High Pressure
Side
Low Pressure
Side
CompressorExpansion Device
1 2
3
4
Advantages Very mature technology. It has very less running cost. It has smaller size for the given capacity of refrigeration. It can be employed over a large range of temperatures. The C.O.P. is very high.
Disadvantages Many systems still use HCFC refrigerants, which
contribute to depletion of ozone layer. Initial cost is high. The prevention of leakage of refrigerant is the major
problem in vapour compression refrigeration.
16
Advantages & Disadvantages of Vapour compression refrigeration
17
Seminar on
“Vapour Compression Refrigeration”
THANK YOU
FOR YOUR ATTENTION
