Apr 18, 2014 vapour compression refrigeration system 1. The vaporcompression refrigeration is the most widely used cycle for refrigerators, air conditioners, and heat pumps. Vapour compression refrigeration system slideshare. Develop simplifying assumptions applicable to gas power. At the start of the transient simulation the boundary conditions are set such that the total mass of refrigerant in the system is kept constant. Heat must be made to flow from a body at low temp to the surroundings at higher temp. The working fluid is a refrigerant that suits the high and low temperature reservoirs temperatures. Which device is used for the expansion of refrigerant in vapour compression refrigeration cycle. Your household refrigerator, water cooler, deep freezer, airconditioner etc, all run on vapor compression cycle. Abstractrefrigeration is the process of removing heat from a closed body or space enclosed so that its temperature is first lowered and then maintained at a required level which is below the temperature of surroundings. Optimization criteria neera jain, student member, ieee, andrew g. Performance aspectsperformance aspects d l difi iand cycle. Schematic for ideal vaporcompression refrigeration cycle. This is the series of articles that describe what is refrigeration, and methods of refrigeration like ice refrigeration, dry ice refrigeration classified as noncyclic refrigeration processes.
In a vapour cycle the working fluid undergoes phase change and refrigeration effect is due to the vaporization of refrigerant liquid. Vapor compression refrigeration system basic, working. Pdf performance improvement of the vapour compression. View homework help chapter 11 vapor compression problems solutions. Th movement cooling by the removal of heat the movement of heat from a place where it is notot a ted to a wanted to a.
Gas turbine systems to compress the intake combustion air. Its function is to provide a heat transfer surface through which heat can pass from the refrigerated space into the vaporizing refrigerant. Performance improvement of the vapour compression refrigeration cycle by a two. The saturated vapour curve and the boiling point curve meet at the critical point k. Type of refrigerant, required refrigeration capacity, evaporator and condenser temperatures are known. The water leaves the evaporator as a saturated vapour at 10 c. Layout of the r22 vapourcompression refrigeration system.
In the vapor absorption process, the compression process of the vapor compression cycle is replaced by an absorber, a generator and a pump. Performance aspectsperformance aspects d l difi iand cycle modifications. Heat is a form of energy and is measured british in btus. Vapour compression refrigera tion system, refrigerant, ozone depletion, global warming, cfc. Vapor compression cooling for high performance applications. The effects of the main parameters of performance analysis are mass flow rate of refrigerant. It is also used in domestic and commercial refrigerators, largescale warehouses for chilled or frozen storage of foods and meats. Vocabulary background in the thermodynamics and refrigeration literature, several words are used interchangeably that can cause confusion. Refrigeration cycle is the basis of all refrigeration systems. Vapour compression refrigeration cycle simulator operating parameters.
Development of vapour compression refrigeration cycle a k bajpai 1 and vivek dwivedi 2 it will be possible only if heat is transferred from the low temperature region to a high temperature region. Compressor basic refrigeration cycle evaporator condenser receiver expansion device. The low temperature, low pressure vapor at state b is. Thermal unit a btu is the quantity of heat required to raise the temperature, of one pound of. Cycle with a regenerator internal heat exchanger 22. The main difficulties of the carnot cycle are overcome by complete condensation in the condenser and by superheating optional. The principle of the system is to make use of two substances that can be separated when heated. Vetriselvan abstract in this analysis, the performance of compression cycle is assessed theoretically with different refrigerants. Referring to figure2, the percentage decline in the evaporator temperature % tevap with liquidsuction subcooler cycle, use the formula, 100% t t t % ideal t ideal subx. The above figure shows the objectives of refrigerators and heat pumps. In this experiment, dichlorofluoroethane r141b was used as the refrigerant and the mass.
While some people have viewed this method as environmentally harmful and inefficient, the cycle is still applicable in the industrial sphere. One of the common refrigeration systems in use today is the vapor compression cycle. The purpose of a refrigerator is the removal of heat, called the cooling load, from a lowtemperature medium. Twostage transcritical compression cycle with two evaporators, separatorflash. Refrigeration cycle refrigeration is the transfer of heat from a lower temperature region to a higher temperature region refrigeration cycle is the vapor compression refrigeration cycle, where the refrigerant is vaporized and condenses alternately and is compressed in the vapor phase. Threestage compression cycle with one evaporator and intercoolerflash tanks 73. We want to design a vaporcompression refrigeration cycle to absorb heat from a cool environment and reject it to a warm environment. Pdf on mar 23, 2015, maqbool ur rehman and others published vapour compression cycle find, read and cite all the research you need on. A compressor which compresses the vaporous working fluid. A second law analysis is performed at the end of the study. The steam cycle is a practical one, it is the basis of virtually all steam power plants and hence electricity generation. We would like to show you a description here but the site wont allow us.
A compressor which compresses the vaporous working fluid and providing required mechanical energy, 9 6, to the system. Comparing the absorption refrigeration cycle with the more familiar vapor compression refrigeration cycle is often an easy way to introduce it. Chapter 10 refrigeration cycles ideal and actual vapor. The vapor refrigeration cycle consists of four stages of process. Chapter 10 refrigeration cycles 103 ideal and actual vaporcompression cycles 104c yes. Cop of a refrigeration cycle and its cooling capacity for specified heat exchange conditions. Vapour compression refrigeration cycle mcqs with answers q1. Vapour compression refrigeration cycle mcqs with answers. Refrigerants for vapour compression refrigeration systems. Show the schema of the vapor refrigeration system as in figure 1.
The system uses two coolants, the first of which performs evaporative cooling and is then absorbed into the second coolant. The vapor compression refrigeration cycle is nearly 200 years old, but it does not seem ready to leave the scene any time soon. Chapter 11 refrigeration cycles the reversed carnot cycle 111c because the compression process involves the compression of a liquidvapor mixture which requires a compressor that will handle two phases, and the expansion process involves the expansion of highmoisture content refrigerant. Vapor compression refrigeration is being adapted to cool computer and telecommunications equipment in a limited number of high performance applications. Layout of the r22 vapour compression refrigeration system. It is used for all industrial purposes from a small domestic refrigerator to a big air conditioning plant. Simulation analysis of compression refrigeration cycle. The vapor compression refrigeration cycle is a common method for transferring heat from a low temperature to a high temperature. The schematic diagram of the arrangement is as shown in fig. Water may instead be used as the absorbent and ammonia as the refrigerant. So refrigeration cycle should be known to understand the refrigeration system.
The vapor compression cycle is the mostly widely used method of refrigeration in the modern applications. Refrigeration and air conditioner equipment to move heat from one place to another in refrigerant cycles. Review of vapour absorption refrigeration and vapour. These systems consist of an evaporator, a condenser, a compressor and an expansion valve.
Week 6 vp refrigeration cycle me 354 tutorial page 2 of 2 question a large refrigeration plant is to be maintained at 15oc, and it requires refrigeration at a rate of 100 kw. System description the layout of the system is shown in figure 1. The log ph diagram shows the thermodynamic state vari ables in the respective. Compressor is said to the heart of the vapour compression system compresses the vapour refrigerant from the. Theoretical backgound vapour compression heat pumps are refrigeration systems whose operational cycle is based on the reversed rankine. The most frequently used refrigeration cycle is the vaporcompression refrigeration cyclein which the refrigerant is vaporized and condensed alternately and is compressed in the vapor phase. Modeling and investigation of refrigeration system. In a vapour cycle the working fluid undergoes phase. The cycle is called as vapor compression cycle, because the vapors of refrigerant are compressed in the compressor of the refrigerator system to develop the cooling effect.
The compression cycle is given this name because it is the compression of the refrigerant by the compressor which permits transfer. The main difference between the two systems is the way the refrigerant is changed from a gas back into a liquid so that the cycle can repeat. The refrigeration cycle is shown in figure below and can be broken down into. Generally refrigeration systems can be classified in 3 main cycle systems which are vapor compression refrigeration system, vapor absorption refrigeration system. Vapor absorption refrigeration cycle or vapor absorption refrigeration systemvars pdf. There are no appreciable pressure drops as the refrigerant flows through the condenser and evaporator. It also describes cyclic methods of refrigeration like vapor compression cycle, vapor absorption cycle etc. Commercial industry storing purified or manufactured gases in a small volume, high pressure cylinders for medical, welding and other. The design is to be based upon the ideal vaporcompression refrigeration cycle, with four components. Refrigeration cycles the vapor compression refrigeration cycle is a common method for transferring heat from a low temperature to a high temperature. The diffuser is designed with a profile that controls momentum change. Analysis of vapour compression refrigeration cycle tce.
Mathematical model of a vapour absorption refrigeration unit the absorbentrefrigerant part need not necessarily be lithium bromide and water. Some basic refrigeration cycles are discussed here through different diagrams. The standard vapor compression refrigeration system is a condenser, evaporator, throttling valve, and a compressor. Properties of applicable operating fluids are presented and r245fa is selected. Simulation analysis of compression refrigeration cycle with. The different stages in the refrigeration cycle are undergone in these physical systems. This case study demonstrates the modeling of a vapour compression refrigeration system using r22 as refrigerant. Besides using ecofriendly refrigerants, thrust has been given upon devising methods to increase the efficiency of the refrigeration cyclesystem, which will. Improved vapour compression refrigeration cycles purdue epubs. A vapor compression refrigeration system uses a refrigerant sealed in an airtight and leak proof mechanism. First, evaporation is simply the process of vaporization these two terms are essentially synonymous.
Modeling and investigation of refrigeration system performance with twophase fluid injection in a scroll compressor rui gu marquette university recommended citation gu, rui, modeling and investigation of refrigeration system performance with twophase fluid injection in a scroll compressor 2016. Refrigeration cycle unit air conditioning unit principle operation of refrigerator what is a refrigerating machine. Lecture16 simple vapour compression refrigeration system a vapour compression refrigeration system is an improved type of air refrigeration system in which a suitable working substance, termed as refrigerant is used. Main parts of vapor compression refrigeration cycles. Thermodynamicsbased optimization and control of vapor. Simulation analysis of compression refrigeration cycle with different refrigerants p. Refrigeration systems refer to the different physical components that make up the total refrigeration unit. A device which will either coolmaintain a body at a temperature below the surroundings. The resulting refrigerant vapor returns to the compressor inlet at point 1 to complete the thermodynamic cycle. Such systems tend to be more complex primarily due to the volatility of the absorbent which requires the use. Dec 01, 2016 page 5 of practical vapour compression refrigeration cycle in practice the reverse carnot cycle is adjusted to the vapour compression refrigeration cycle shown below in figure 3. Both a steadystate and a transient simulation will be considered. The vapour compression cycle which is used in vapour compression refrigeration system is nowadays used for all purpose refrigeration.
Vapor compression refrigeration cycle engineering essay. An absorption refrigerator changes the gas back into a liquid using a method that needs only heat, and has no moving parts other than the fluids. Highlights a design procedure is presented for an ejection refrigeration system. Vapourcompression refrigeration or vaporcompression refrigeration system vcrs, in which the refrigerant undergoes phase changes, is one of the many refrigeration cycles and is the most widely used method for airconditioning of buildings and automobiles. During the process cycle, the pressure change occurs which is used to govern the working refrigerant to consume or remove the heat energy. Similarly, two alternative designs for the evaporator are developed and simulated. Obviously it is not possible in the natural manner because heat flows from high. An absorption refrigerator is a refrigerator that uses a heat source e.
Thermodynamicsbased optimization and control of vaporcompression cycle operation. Performance analysis of vapour compression refrigeration system with r404a, r407c and r410a jyoti soni 1 and r c gupta corresponding author. Page 5 of practical vapour compression refrigeration cycle in practice the reverse carnot cycle is adjusted to the vapour compression refrigeration cycle shown below in figure 3. In the transient case the temperature at node 9 is reduced from 30. A textbook of refrigeration and air conditioning simple vapour.
Superheating and sub cooling process will influence the cooling capacity and compressor work. Vapour compression refrigeration or vaporcompression refrigeration system vcrs, in which the refrigerant undergoes phase changes, is one of the many refrigeration cycles and is the most widely used method for airconditioning of buildings and automobiles. The vapor compression refrigeration cycle, step by step. Flownex network of the vapour compression refrigeration system. Schematic of a vapour compression refrigeration cycle is shown in fig. There are many types in refrigeration cycle the vapour compression cycle is taken for the. Experimental analysis on vapour compression refrigeration vcr system with r4a tetra fluro ethane refrigerant was done and their results were recorded. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext.
In gas cycles, heat rejection and refrigeration take place as the gas undergoes sensible cooling and heating. The refrigeration lab was conducted to gain a better understanding of the vaporcompression refrigeration cycle and to compare the ideal cycle with a real cycle. Micro refrigerator, electronic cooling, micro evaporatorcondenser, microchannels, vapor compression refrigeration cycle. Simple vapour compression system the schematic diagram of the arrangement is as shown in fig. Vapor compression can lift large heat loads and can heat sink at below ambient temperatures. Consider the internallyreversible refrigeration cycle shown in figure i which is designed to provide a specified cooling capacity q to a flowing stream which enters at temperature tl and flowrate rht.