Cycle with dry saturated vapour after compression 2. A free powerpoint ppt presentation displayed as a flash slide show on id. Vapour compression refrigeration or vapor compression 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. In practice, the working fluid of the lower cycle is at a higher.
So, a chiller is a machine that removes heat from a liquid via a vapour compression or absorption refrigeration cycle. Air refrigeration operates on a carnot cycle b reversed carnot cycle c rankine cycle d. The brayton refrigeration cycle is the reverse of the brayton power cycle introduced in sec. Difference between vapour compression and vapour absorption pdf. Const p heat addition saturated water enters the boiler and leaves it as. The selection of working fluid has a significant impact on the performance of the refrigeration cycles and as such it plays a. Vapourcompression refrigeration or vaporcompression refrigeration system vcrs, in which. Saturated vapor enters the compressor at 10c and saturated liquid leaves the condenser at 9 bar.
Pdf on mar 23, 2015, maqbool ur rehman and others published. Vapour compression cycle free download as powerpoint presentation. In the vapor absorption process, the compression process of the vapor compression cycle is replaced by an absorber, a generator and a pump. However, the absorption cycle uses different refrigerants and a different method of compression than the vapor compression cycle. However, for interested readers, closed cycle adsorption technology is briefly described below. What is vapour compression cycle engineering insider. Vapor compression refrigeration an overview sciencedirect. Basic refrigeration cycle and concepts, standard rating of refrigerating machines. Useful refrigeration and net work of the carnot cycle shown. From there the vapour refrigerant flows through a tube to the inlet of the compressor 1 to close the cycle. The principle of the system is to make use of two substances that can be separated when heated. Vapour compression cycle generally known as vcc is a refrigeration cycle. This is the part of the refrigeration system that is doing the actual cooling.
In gas cycles, heat rejection and refrigeration take place as the gas undergoes sensible cooling and heating. A typical vapor compression cycle system is a closed loop system and includes a compressor, a condenser, an expansion device and an evaporator. Vapor absorption refrigeration cycle or vapor absorption refrigeration system vars pdf. Vapor compression refrigeration system basic, working, parts of.
The refrigerant absorbs heat from one place and releases it to another place. Cycle with superheated vapour before compression 5. Since the vapor compression cycle is against the second law of thermodynamics, some work is necessary for the transfer to take place. A working fluid often called the refrigerant is pushed through the system and undergoes state changes from liquid to gas and back. A reversible, adiabatic isentropic compression of the refrigerant. Each of the four stages will now be revisited in detail, explaining the physical changes that occur in the refrigerant and the devices used to accomplish these changes. In other words, the vapour compression cycle is a process used to extract heat from a box or a room that underlies most refrigeration and air conditioning techniques. Cop of air refrigerator working on reversed carnot cycle with pv and ts diagram mechanism and working of vapour compression refrigeration system with pv and ts diagram equation of coefficient of performance cop of bell coleman cycle heat absorbed during cycle per kg of air q 41 cpt 1t 4. The vapor compression refrigeration cycle is nearly 200 years old, but it does not seem ready to leave the scene any time soon. It readily evaporates and condenses or changes alternatively between the vapor and liquid phase without leaving the refrigerating plant. In this cycle, the refrigerant is sealed condition in an airtight mechanism is compressed in a compressor which permits the transfer of heat energy.
Layout of the r22 vapour compression refrigeration system. The highpressure refrigerant flows through a condenserheat. Q1 the equivalent of latent heat of condensation etc, is lost from the. The work is supplied to the system from the surroundings. Vapour compression cycle definite guide with video. As there is no condensation and evaporation intended in this gas cycle, components corresponding to the condenser and evaporator in a vapour compression cycle are the hot and cold gastogas heat exchangers. Refrigerant r22 vapour enters a positive displacement compressor at a slightly. Vapour compression cycle refrigeration atmospheric. The vapor compression cycle is made possible because the refrigerant is a fluid that exhibits specific properties when it is placed under varying pressures and temperatures. Vapor compression refrigeration system basic, working, parts of system, advantages, and disadvantages introduction. Cop heat extracted at low tempreature work sup plied heat extracted at low temperature heat transfer during the. It is a compression process, whose aim is to raise the refrigerant pressure, as it flows from an evaporator. Vapour compression cycle energy management handbook sixth edition, chapter 8 refrigerator air conditioning plant heat pump refrigerator electricmotordriven.
Gandhinagar institute of technology subject applied thermal and hydraulic engineering2140907 branch electrical topic refrigeration vapour compression refrigeration system 2. In an ideal vaporcompression refrigeration cycle, the refrigerant enters the. Brayton refrigeration cycle the working fluids of vapor compression systems undergo liquidtovapor phase change. Intro refrigeration cycle, vapor compression randall manteufel. Before moving further on differences lets have an overview of both the vapour compression and vapour absorption refrigeration system. Refrigerant 4a is the working fluid in an ideal vapor compression refrigeration cycle that communicates thermally with a cold region at 10c. Natural gas plants, petroleum refineries, and petrochemical plan. Dec 17, 2017 vapour compression cycle is a cycle employed for obtaining low temperatures in refrigerators and air conditioners. Vapor compression cycle working diagram a refrigeration system can also be used as a heat pump, in which the useful output is the hightemperature heat rejected at the condenser. While some people have viewed this method as environmentally harmful and inefficient, the cycle is still applicable in the industrial sphere. The vapor compression refrigeration cycle, step by step araner. At the bottom of the articles you can download pdf. Aug 30, 2019 vapor compression refrigeration cycle.
Mechanism and working of a vapour compression refrigeration. Isentropic compression water enters the pump as state 1 as saturated liquid and is compressed isentropically to the operating pressure of the boiler. The most widely used refrigeration cycle is the vaporcompression refrigeration cycle. First, evaporation is simply the process of vaporization these two terms are essentially synonymous. The vaporcompression refrigeration cycle the vaporcompression refrigeration cycle has four components. In a vapour cycle the working fluid undergoes phase. In this chapter, only open cycle solid desiccant cooling technology has been discussed. Much like in the vapor compression cycle, refrigerant in the absorption cycle flows through a condenser, expansion valve, and an evaporator. The working principle of a closed cycle solid desiccant based cooling system is similar to that of a vapor compression refrigeration system. Brief overview of vaporcompression refrigeration cycle, major components and heatwork transfers. It is also used in domestic and commercial refrigerators, largescale warehouses for. Because its function is to absorb heat into the refrigeration system from where you dont want it, the evaporator is placed in the area to be cooled.
It is then throttled to the evaporator pressure and vaporizes as it absorbs heat from the refrigerated. The vapor compression refrigeration cycle involves four components. Vapour compression cycle is an improved type of air refrigeration cycle in which a suitable working substance, termed as refrigerant, is used. Vapor compression refrigeration systems are used for a variety of coolingrefrigeration applications. Vapour compression systems have mainly four elements in the refrigeration system i. Representation of vapour compression refrigeration. The singlestage compression cycle discussed above is the simplest and the most commonly used cycle. In brayton refrigeration systems the working fluid remains a gas throughout.
Performance analysis of vapour compression refrigeration system with r404a, r407c and r410a jyoti soni 1 and r c gupta corresponding author. Ppt vapour compression cycle powerpoint presentation free. Refrigeration and air conditioning pdf book agrimoon. Domestic refrigerator working on vapour compression cycle uses the following type of expansion device a electrically operated throttling valve b manually operated valve c thermostatic valve d capillary tube e expansion valve. Cop of air refrigerator working on reversed carnot cycle with pv and ts diagram. Each stage operates on an ideal vapor compression refrigeration cycle with refrigerant r4a as working fluid. Refrigeration cycle l vapour compression refrigeration. Alternatively, a refrigeration system can be used for providing cooling in summer and heating in winter. The refrigerants generally used for this purpose are ammonia nh 3, carbon dioxide co 2 and sulphurdioxide so 2.
Today we will study the difference between vapour compression and vapour absorption refrigeration system in detail. The vapor compression refrigeration cycle, step by step. The vapor compression cycle in aircraft airconditioning systems. Refrigerants are working substances or heat carrying medium in refrigeration system, during a refrigeration cycle heat is absorbed from a low temperature system. System description the layout of the system is shown in figure 1. The saturated vapour at state 1 is superheated to state 2. Vocabulary background in the thermodynamics and refrigeration literature, several words are used interchangeably that can cause confusion. Both a steadystate and a transient simulation will be considered. Intro refrigeration cycle, vapor compression youtube. The vapor compression cycle circulates a fluid through a compressor, condenser, expansion valve, and evaporator, in order to absorb heat from a refrigerated space at a low temperature and give off heat at a higher temperature to the surroundings, thus keeping the refrigerated space cool. Vapor compression refrigeration system basic, working. However, under some circumstances it becomes advantageous to consider devices in which the compression of the vapour occurs in two or more stages, termed multistage systems.
The vapor compression refrigeration cycle is a common method for transferring heat. This is a pdf on the basic vapour compression cycle. Mar 26, 2007 vapor compression refrigeration cycle this refrigeration cycle is approximately a rankine cycle run in reverse. Absorption chillers utilize water as the refrigerant and hence rely on the strong affinity between the water and a lithium bromide solution to achieve a refrigeration effect. Layout of the r22 vapourcompression refrigeration system. Vaporcompression refrigeration, 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 latent heat of vaporization of the refrigerant is used to transfer large amounts of heat energy.
The rankine cycle is the ideal cycle for vapor power plants. An internally, reversible, constant pressure heat rejection in which the working substance is desuperheated and then condensed to a saturated liquid at 3. Refrigeration cycle l vapour compression refrigeration cycle. Heat rejection from the lower cycle to the upper cycle takes place in an adiabatic counterflow heat exchanger where both streams enter at about 0. Apr 02, 2016 vapour compression refrigeration system 1.
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