Vapour Compression Refrigeration System Ppt Download For Mac
Vapour Compression Refrigeration System Ppt Download For Mac Free
- View and Download PowerPoint Presentations on VAPOR COMPRESSION REFRIGERATION CYCLE PPT. Find PowerPoint Presentations and Slides using the power of XPowerPoint.com, find free presentations about VAPOR COMPRESSION REFRIGERATION CYCLE PPT. Miniature Vapor Compression Refrigeration System for Active. Are higher than what can be handled.
- Vapor-compression refrigeration, in which the refrigerant undergoes phase changes, is one of the many refrigeration cycles and is the most widely used method for air-conditioning of buildings and automobiles.
RA1 MkII - Vapour-Compression Refrigeration Unit - Free download as PDF File (.pdf). Refrigeration system Vapour-compression type Refrigerant R134a Compressor. Kesehatan-gigi-dan-mulut1.pptCargado por NITA.
REFRIGERATION: REFRIGERATION The term ‘ refrigeration’may be defined as the process of removing heat from a substance under controlled condition. In other words the refrigeration means a continued extraction of heat from a body whose temperature is already below the temperature of its surrounding. UNITS OF REFRIGERATION- The practical unit of refrigertion is expressed in terms of “ tonne of refrigeration.
REFRIGERANT- Refrigerant is a heat carrying medium in the refrigeration system,which absorb heat from the low temp system and discard heat so absorb to a higher temperature system. In the vapour absorption refrigeration system we use ammonia as the refrigernt. PowerPoint Presentation: In this system the low pressure amonia vapour leaving the evaporator enters the absorber where it is absorbed by the cold water in the absorber. The water has ability to absorb very large quantities of of ammonia vapour and the solution thus is formed,is known as aqua-ammonia. The absorption of ammonia vapour in water lowers the pressure in the absorber which in turns draws more ammonia vapour from the evaporator and thus rises the the temperature of solution. Some form of cooling arrengement ( usually water cooling)is employed in the absorber to remove the heat of the solution evolved here. This is necessary in order to increase the absorbing capacity of water because higher temperature water absorbs less ammonia vapour.
PowerPoint Presentation: The strong solution thus formed in the absober is pumped to the generator by the liquid pump. The strong solution of ammonia in the generator is heated by some external source such as gas or steam. During the heating process the ammonia vapour isdriven off the solution at high pressure leaving behind the hot weak ammonia in the generator. This weak ammonia solution flows back to the absorber at low pressure after passing through the pressure reducing valve. The high pressure ammonia vapour from the generator is condensed in the condenser to ahigh pressure liquid ammonia which passedto the expansion valve trough the receiver to the evaporator. PRACTICAL VAPOUR ABSORPTION SYSTM: PRACTICAL VAPOUR ABSORPTION SYSTM Itmainly consists of three parts ANALYSER RECTIFIER HEAT EXCHANGER ANALYSER-When ammonia is vapourised in the generator some water is also vapourised,and flow into the condenser along with ammonia.
If these unwanted particle are not removed before entering into the condenser,they will enter into the expansion valve where they freeze and choke the pipe line,so in order to remove the unwanted particle flowing in the condeser the analyser is used. PowerPoint Presentation: This type of refrigerator is also called a three fluid absorption system. It is called three fluid absorption system because it uses 3 fluids such as ammonia,hydrogen and water. Here in this refrigeration system the movable part that is the pump is not used,there fore it produces less noise and less wear and tear property. In the generator,the ammonia vapour is formed due to heating of strong ammonia solution.
This formed ammonia vapour is passed through separator,analyser,rectifier to remove the water particles and water vapour is carried out by ammonia. PowerPoint Presentation: The dehydrated ammonia vapour is passed to the main- condenser,where 90% vapour is condensed here and the remaining 10% is further condensed in the helping-condenser. This condensed high pressure ammonia liquid is passed to the evaporator of section A and B and it is evaporated in the presence of hydrogen atmoshpere. The mixture of ammonia vapour and hydrogen is passed to the absorver through the gas heat exchanger,the hot hydrogen coming from absorver is cooled by cold mixture of hydrogen and ammonia coming from evaporator. Comparision between absorption system and compression system: Comparision between absorption system and compression system ABSORPTION SYSTEM- 1-Use low grade energy like heat there fore,may be worked on exhaust system from I.C engine etc. 2-Moving part are only in the pump,which is small element of the system,Hence the operation is smooth. 3-The system can work on lower evaporator pressure also without affecting the cop.
4-No effect of reducing the load on performance. COMPRESSION SYSTEM- 1-Use high grade energy mechanical work.
2-Moving parts are in the compressor there fore more wear,tear and noise is produced. 3-The cop decreases considerably with decrease in evaporator pressure. 4-Performance is adversely affected at partial load. COP OF AN IDEAL VAPOUR ABSORPTON REFRIGERATION SYSTEM-: COP OF AN IDEAL VAPOUR ABSORPTON REFRIGERATION SYSTEM- C.O.P=Heat absorbed in evaporator/(work done by pump+heat supplied in generator) According to first law of thermodynamics Qc= Qg+Qe Qc=The heat is discharged to the atmoshpere or cooling water from the condenser and absorber. Qg =heat is given to the refrigerant in the generator. Qe =heat is absorbed by the refigerant in the evaporator.
Tg =temperature at which heat( Qg ) is given to the generator. Tc =Temperature at which heat (Qc) is discharged to atmoshpere Te=Temperature at which heat ( Qe ) is absorved in the evaporator. Advantage: advantage As there is no moving part in the entire system,the operation is essentially quite and subjected to a very little wear. The load variations does not effect the performance of a vapour absorption system.
Absorption system may be designed to use any readily available source of thermal energy such as process steam,hot exhaust from furnaces and solar energy,there fore they can be used in places where electric power is hard to obtain or is very expensive. Here pump is used for pumping refrigerant absorbant solution,which consume less power. Maintance cost is low as because of absence of moving part.