Both a steadystate and a transient simulation will be considered. Lesson 2 elementary vapour compression refrigeration cycle 912 lesson 3 representation of vapour compression refrigeration cycle on pv, t and ph diagrams, use of refrigerant properties tables and ph mollior charts. Vapour absorption refrigeration system with diagram. In this paper, the case study was extended to include an expanded search space, inclusion of utility streams and practical design criteria. Any components beyond these basic 4 are called accessories. It is a compression process, whose aim is to raise the refrigerant pressure, as it flows from an evaporator. Refrigeration cycle animation vapor compression cycle. Representation of vapour compression refrigeration. It has a smaller size for the given capacity of refrigeration.
Videos you watch may be added to the tvs watch history and. The main deviations between the theoretical and actual cycle are. The basic difference between vapour compression and vapour absorption cycles will thus be to replace the compressor of the vapour compression cycle by a set of equipment which fulfils the objective discussed above. It is also useful to understand working of vapour compression system, its performance and controls used. The compressor is a vapour compression pump which uses pistons or some other method to compress the refrigerant gas and send it. The points which are required for engineering calculation are from h 1 to h 6 as shown in the figure 16. Vapour absorption system vapour absorption system is an attractive method for utilizing low grade energy directly for cooling. The vapor compression refrigeration cycle, step by step araner.
The vapor compression refrigeration cycle involves four components. The compressor is driven by a heat engine with a thermal efficiency of 40%. Mechanical vapor compression refrigeration cycle has for basic parts 1 compressor 2 condenser 3 expansion device 4. The refrigeration cycle is a critical component of hvac systems and is governed by the principles of thermodynamics. The vapour absorption system uses heat energy, instead of mechanical energy as in vapour compression systems, in order to change the conditions of the refrigerant required for the operation of the refrigeration cycle. Introduction a vapor compression refrigeration system is an improved type of air. Vapour compression cycle is an improved type of air refrigeration cycle in which a suitable working substance, termed as refrigerant, is used. The vapor compression refrigeration cycle is a common method for transferring heat from a low temperature to a high temperature. A refrigeration cycle explained involves the cooling system process of refrigerators and air conditioners. Vapor compression refrigeration systems are used for a variety of coolingrefrigeration applications. Apr 05, 2016 this video is all about mechanical vapour compression refrigeration cycle. If playback doesnt begin shortly, try restarting your device.
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. A textbook of refrigeration and air conditioning simple vapour. The actual vapour compression cycle is different from the theoretical vapour compression cycle in many ways. The heat pump cycle uses an ideal cycle with an evaporator at 5oc and a condenser. Example problem simple vapor compression refrigeration. It also includes the process of maintaining and reducing the temperature of a body below the general temperature of its surroundings. Micro refrigerator, electronic cooling, micro evaporatorcondenser, microchannels, vapor compression refrigeration cycle. 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. The above figure shows the objectives of refrigerators and heat pumps.
Layout of the r22 vapourcompression refrigeration system. The steadystate simulation uses the accurate property correlations developed by. A compressor which compresses the vaporous working fluid and providing required mechanical energy, 9 6, to the system. In the vapour absorption system, an absorber, a pump, a generator and a pressurereducing valve replace the compressor. Components of vapour compression refrigeration cycle compressor the low pressure saturated vapour refrigerant from evaporator drawn into the compressor through suction valve. In this lesson, one will learn how to solve the problems on vapour compression cycle.
Refrigeration cycle animation vapor compression cycle explained. The design problem concerns the replacement of r4a refrigerant. The above figure shows simple vapour compression refrigeration system. Commonly, simple vapour compression refrigeration systems are used for comfort cooling and cold storage application. Adiabatic compression process continues beyond the point where the condensing temperature is reached. A simple vapour compression refrigeration system with simplest expansion device as capillary tube is used in numerous of small or medium refrigeration applications like domestic refrigerator, deep freezer, water cooler, room air conditioners, cooling cabinets and. Suggestions for further improvement of performance of heat pumps refrigeration cycles and their components are also made.
Take the structure image of this refrigeration cycle from figure 15, it becomes the ph diagram for engineering calculation as shown in figure 16. Analysis of a vaporcompression refrigeration cycle maplesoft. Cycle with superheated vapor before compression, and 5. Additionally, a pht chart with the refrigeration cycle will be plotted. Theoretical exergy analysis of hfo1234yf and hfo1234ze. The principle of the system is to make use of two substances that can be separated when heated. System description the layout of the system is shown in figure 1. Vapour compression cycle definite guide with video.
We want to design a vaporcompression refrigeration cycle to absorb heat from a cool environment and reject it to a warm environment. 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 system is fabricated such that students can observe and study ice formation process. Irreversibility within the evaporator, condenser and compressor are ignored no frictional pressure drops refrigerant flows at constant pressure through the two heat exchangers evaporator and condenser heat losses to the surroundings are ignored compression process is. Vapor absorption refrigeration cycle or vapor absorption refrigeration systemvars pdf. There are 4 main components in a mechanical refrigeration system. The compressor, condenser, throttle and evaporator are analyzed separately from each other.
Mar 19, 2020 refrigerant 4a is the working fluid in an ideal vaporcompression refrigeration cycle that communicates thermally with a cold region at 0c and a warm region at 26c. The purpose of a refrigerator is the removal of heat, called the cooling load, from a lowtemperature medium. The simple vapour compression refrigeration cycle is shown in fig. This video is all about mechanical vapour compression refrigeration cycle. Natural gas plants, petroleum refineries, and petrochemical plan. Review of vapour absorption refrigeration and vapour. This is the amount of heat required to turn a liquid into a gas. The simple vapour compression cycle is superimposed on the ph diagram in fig.
At the bottom of the articles you can download pdf. A refrigerant design problem for a vaporcompression refrigeration cycle was presented previously gani et al. Refrigeration may be defined as a process of removing heat from a substance and pumping it to the surroundings. Before moving further on differences lets have an overview of both the vapour compression and vapour absorption refrigeration system. Simple vapour compression refrigeration system with. Vapor compression refrigeration an overview sciencedirect.
Heat removed from the engine in the cooling system is recovered. Refrigeration and air conditioning pdf book agrimoon. Pdf simulation of a simple vapourcompression refrigeration. Cycle with under cooling or sub cooling of refrigerant, advantages of vapour compression system. Pdf a computerized simulation of a simple singlestage vapourcompression refrigeration system has been made. The refrigeration system were also used for providing cooling and humidification for summer comfort air conditioning 3. There are no appreciable pressure drops as the refrigerant flows through the condenser and evaporator. This is often measured at the liquids boiling point. Case1 the basics of refrigeration cycle ph diagram analysis. The highpressure refrigerant flows through a condenserheat exchanger before attaining the initial. A computerized simulation of a simple singlestage vapour compression refrigeration system has been made.
In this article we will discuss about simple vapour compression refrigeration system. Layout of the r22 vapour compression refrigeration system. In this cycle, the refrigerant is sealed condition in an airtight mechanism is compressed in a compressor which permits the transfer of heat energy. Vapor compression refrigeration system basic, working, parts of system, advantages, and disadvantages introduction. A second law analysis is performed at the end of the study. When simple vapour compression cycle is displayed on the temperatureentropy diagram fig. Vapour compression cycle generally known as vcc is a refrigeration cycle. Before we dive in, lets get an understanding of four key concepts. H 1 to h 2 is the adiabatic compression of the compressor for the simple refrigeration system. International journal for research in applied science. 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. In the vapor absorption process, the compression process of the vapor compression cycle is replaced by an absorber, a generator and a pump. 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. This paper deals about simple vapor compression system, its various components and about the coefficient of performance cop of vapor refrigeration system.
Smaller in size with a given capacity of refrigeration. A reversible, adiabatic isentropic compression of the refrigerant. A computerized simulation of a simple singlestage vapourcompression refrigeration system has been made. Vapour compression refrigeration cycle mcqs with answers q1. The scientists investigate more environmentally friendly refrigerants to resolve. This is an important advantage as against the conventional vapour251compression system which operates on high grade energy.
Apr 02, 2016 vapour compression refrigeration system 1. Twostage compression cycle with one evaporator and intercooling with flash gas 53. In this type of refrigerator, refrigerant undergoes phase changes. The steadystate simulation uses the accurate property correlations developed by cleland. Mechanism of simple vcrs assumptions for ideal vaporcompression cycle are. Vapour compression refrigeration cycle mcqs with answers. The saturated vapor at state 1 is superheated to state 2. Leakage of the refrigerant is the major problem in the simple vapour compression cycle. Refrigeration cycles the vapor compression refrigeration cycle is a common method for transferring heat from a low temperature to a high temperature.
In simple commercial refrigeration systems the compressor is normally. Twostage compression cycle with one evaporator and intercooler with water 51. A simple vapour compression cycle is shown by 12341 on ph chart of fig. Compressor basic refrigeration cycle evaporator condenser receiver expansion device. Depending upon the applications evaporating temperature varies from 50 c to 7 c bilal and syed, 2011. Basic refrigeration cycle and concepts, standard rating of refrigerating machines. Vapor compression refrigeration system basic, working, parts of.
Vapourcompression refrigeration or vaporcompression refrigeration system vcrs, in which. Sep 10, 2016 the refrigeration cycle is a critical component of hvac systems and is governed by the principles of thermodynamics. It is also used in domestic and commercial refrigerators, largescale warehouses for. It can be employed over a large range of temperatures. Ts and ph diagrams for an ideal vaporcompression refrigeration cycle. The evaporation process or vaporisation of refrigerant is a constant pressure process and therefore it is represented by a horizontal line. For a closed cycle of refrigeration employing the condensable refrigerant vapour, the following processes are required. From the first law of thermodynamics, coefficient of performance cop is the measure of performance of the cycle, which is defined as refrigeration effect desired effect produced per unit of work required. The vapor compression cycle explained is the most common type of system used in refrigeration and air conditioning.
Twostage compression cycle with one evaporator and intercoolerflash tank 55. The refrigerant absorbs heat from one place and releases it to another place. Vapor compression refrigeration system basic, working. Which device is used for the expansion of refrigerant in vapour compression refrigeration cycle. Here harshit solves some sample questions which will help one to recollect and remember all the topics and equations which were discussed in the previous lesson. The vapour compression cycle which is used in vapour compression refrigeration system is nowadays used for all purpose refrigeration. In the compression process the energy used to compress the vapour turns into heat and increases its temperature and. Similarly, two alternative designs for the evaporator are developed and simulated. Schematic of a vapour compression refrigeration cycle is shown in fig.
The design is to be based upon the ideal vaporcompression refrigeration cycle, with four components. In the compression process the energy used to compress the vapour turns into heat and increases its temperature and enthalpy, so that at the end of. Theoretical exergy analysis of hfo1234yf and hfo1234ze as. It is also used in domestic and commercial refrigerators, largescale. Difference between vapour compression and vapour absorption pdf. 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. Today we will study the difference between vapour compression and vapour absorption refrigeration system in detail. Compression cycle an overview sciencedirect topics. Simple vapour compression refrigeration system with diagram. First, evaporation is simply the process of vaporization these two terms are essentially synonymous. Vocabulary background in the thermodynamics and refrigeration literature, several words are used interchangeably that can cause confusion. Most of the modern refrigerators work on this cycle, in its simplest form, there are four fundamental operations required to complete one cycle. The simplest explanation of this system is a heat engine working in reverse, technically referred to as reverse carnot engine. A heat pump uses a vapour compression cycle with refrigerant 12.
Vapor compression refrigeration systems are used for a variety of cooling refrigeration applications. One of the common refrigeration systems in use today is the vapor compression cycle. Mechanism and working of a vapour compression refrigeration. This case study demonstrates the modeling of a vapour compression refrigeration system using r22 as refrigerant. Feb 10, 2017 mechanism of simple vcrs assumptions for ideal vapor compression cycle are. The vapor compression refrigeration cycle is nearly 200 years old, but it does not seem ready to leave the scene any time soon. It is used for all industrial purposes from a small domestic refrigerator to a big air conditioning plant. This amounts to 40% of the energy supplied in the fuel.
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