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. The comparison of vapor compression and gas compression refrigerating cycles based on following parameters. Interactive computer routines have been composed, in basic language, in order to permit the prediction of the performances of simple, multievaporator multistage compressor vapour compression refrigerators when employing refrigerant r11, r12, r22 or r502. Schematic of a vapour compression refrigeration cycle is shown in fig. A compressor which compresses the vaporous working fluid. This is a hypothetical example because chemical refrigerants have. Basic component of refrigerator refrigeration systems typically include a compressor, a condenser, an expansion valve, and an evaporator. Heat for the vapour absorption refrigeration system can be provided by waste heat. The objective of this study is to design and simulate a vapor compression refrigeration cycle for a microscale refrigerator. Vapour compression refrigeration cycle on ph diagram the ph diagram is frequently used in the analysis of vapour compression refrigeration cycle and usually consists of the four processes. This is achieved by using a substance called a refrigerant, which absorbs heat and hence boils or evaporates at a low pressure to form. Multistage compression refrigeration similar to a cascade system except the same fluid is used for both stages compression is done in two stages with a mixing chamber in between. Able to analyze the efficiency of refrigeration system.
Vapor compression system takes in high grade such as electrical or mechanical energy for its operation of compressor used in the cycle. In the gas cycle the gas like air is used as the refrigerant. Experimental mapping of the thermodynamic losses in vapor. The refrigerant as a mixture of liquid and vapour corresponding to state point 1 enters the compressor where isentropic compression takes place.
An internally, reversible, constant pressure heat rejection in which the working substance is desuperheated and then condensed to a saturated liquid at 3. Vapor compression refrigeration cycle engineering essay. Types of refrigeration systems mainly they are classified under two groups. Pdf experimental analysis of a vapour compression refrigeration. According to the requirement, vapour compression system is further modified for better performance and control. Finally, refrigerant22 r22 is a chemical used in many refrigeration systems.
The refrigerants hfc152a, hfc32, hc290, hc1270, hc600a and re170 were used as the working fluid for the comparison with the conventional refrigerant r4a. Vapourcompression refrigeration systems sciencedirect. After the development of the vapour compression cycle, the vapour absorption cycle lost much of. Basic vapour compression refrigeration cycle consists of four major thermal processes. This is the part of the refrigeration system that is doing the actual cooling. A reversible, adiabatic isentropic compression of the refrigerant.
What are the differences between the vapour compression. One of the common refrigeration systems in use today is the vapor compression cycle. The clearance volume losses a portion of cylinder volume for suction which reduces the compressor efficiency. It also includes the process of maintaining and reducing the temperature of a body below the general temperature of its surroundings. The vapour compression refrigerator employs the following cycle a rankine b carnot c reversed rankine d reversed carnot. Both a steadystate and a transient simulation will be considered. The equations of exergetic efficiency and exergy destruction for the main system components such as compressor, condenser expansion device. Albeit the methodology was originally developed for household refrigerators, it can be easily extended to any kind of vaporcompression refrigeration systems. Compressor, concentration, performance, temperature introduction the most commonly used method of cooling is with vapor compression cycles, because it. In any refrigeration process, heat is transferred from one region to another with the aid of an external agent.
Though the air is heated and cooled in the air conditioning unit it is the refrigeration cycle using r12 refrigerant as the working fluid which is the main focus of the experiment. According to the results of their experiments, the refrigerant r290r600a had a refrigerating capacity 28. Refrigerant4a enters the compressor of a refrigerator as superheated vapor at 0. It has been and is the most widely used method for airconditioning of large public buildings, offices. Power required for the refrigeration system we know that power required for the refrigeration system. Vapor compression refrigeration system basic, working. Vapour compression refrigeration systems as specified, vapour compression refrigeration systems are the most ordinarily utilized among all refrigeration systems. Highly compressed fluids tend to get colder when allowed to expand. The saturated vapour at state 1 is superheated to state 2. In this articles we discussed about difference between vapour compression and vapour absorption refrigeration system and pdf is available.
Heat balance and energy balance of each component of the system will make the perfect energy assessment of the whole system. Lot of heat can be removed lot of thermal energy to change liquid to vapour. These systems belong to the general class of vapor cycles, wherein the working refrigerant undergoes phase change at least during one process. This paper gives the overview of important modifications in vcrs were gifted to society. The four components of the refrigerator, namely, the condenser, evaporator, compressor and the capillary tube are designed separately. The vapour compression cycle which is used in vapour compression refrigeration system is nowadays used for all purpose refrigeration. If the pressure change is high enough, then the compressed gas will be hotter. System description the layout of the system is shown in figure 1. 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. Vapor compression cycle refrigeration is a process that uses the physics of phase change heat transfer and the unique properties of a refrigerant to transfer heat from a relatively cold source to a hot medium. Such systems are compound multistage systems, cascade systems and multi evaporator systems. Vapors compression refrigeration using heat energy. Design of two stage vapour compression refrigeration. How vaporcompression cooling works electronics cooling.
Vapor compression refrigeration system basic, working, parts of system, advantages, and disadvantages introduction. Vapour absorption refrigeration var in the early years of the twentieth century, the vapour absorption cycle using ammoniawater systems was popular and widely used. Vapor compression refrigeration is one of the many refrigeration cycles available for use. The conventional vapour compression refrigeration system consists of four major components namely compressor, condenser, expansion device and evaporator. Malwe refrigerator, which is so common and runs continuously everywhere. It is also used in domestic and commercial refrigerators, largescale warehouses for chilled or frozen storage of foods and meats. No measurable 970 btus are required to 250 212 100 boiling water sensible steam heat latent heat temperature change measurable tt change the water to steam. Vapour compression cycle consists of phase change from gas to liquid in condenser and the compressor pumps liquid phased refrigerant. Refrigeration may be defined as a process of removing heat from a substance and pumping it to the surroundings. Refrigeration fundamentals 2175 west park place blvd. In the vapour absorption system, an absorber, a pump, a generator and a pressurereducing valve replace the compressor.
Performance analysis of vapour compression refrigeration. Generally refrigeration systems can be classified in 3 main cycle systems which are vapor compression refrigeration system, vapor absorption refrigeration system. In this paper exergetic approach is used to analysis the performance of theoretical vapour compression refrigeration cycle using r404a, r407c and r410a. Performance estimation of vapour compression refrigeration system using real gas model article pdf available in iop conference series materials science and engineering 3901. Experimental analysis of a vapour compression refrigeration system by using nano refrigerant r290r600aal2o3. Sukamto et al 1 in his research report that the use of liquidsuction subcooler on cooling machine using the working fluid r22 can increase the coeffisients of performance cop to a variety of environmental temperature. The compression process increases the temperature of. Now we have a heat pump that employs vapor compression refrigeration cycle for cooling. It is used for all industrial purposes from a small domestic refrigerator to a big air conditioning plant. Difference between vapour compression and vapour absorption. Compression refrigeration cycles in general take advantage of the idea that highly compressed fluids at one temperature will tend to get colder when they are allowed to expand. Vapour compression units are the most widely used refrigeration systems. Making it more efficient as compression work per unit of mass flow is low. This case study demonstrates the modeling of a vapour compression refrigeration system using r22 as refrigerant.
Multiple choice questions with answers on refrigeration. Refrigeration cycle system modelling of the vapor compression experimental unit with the goal to predict the system performance of the cycle. The effects of the main parameters of performance analysis such as refrigerant type. 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. After the first expansion, a liquidvapor mix is present. 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. Layout of the r22 vapour compression refrigeration system. Exergy analysis of vapour compression refrigeration system. Cop in vapor compression refrigeration analysis physics. In the vapor compression refrigeration system, which is widely used, the external agent is a compressor. In vapor compression cycle liquids like freon and ammonia are used as the refrigerant. The compressor work requirement of vapor compression refrigeration system working with r4alpg 28. Page 4 of 4 theory of vapour compression refrigeration cycles carnot cycle this experiment uses a vapour compression refrigeration cycle which cools air down.
Layout of the r22 vapourcompression refrigeration system. In the open system the refrigerator is replaced by the actual space to be cooled with the air expanded to atmospheric pressure, circulated through the cold room and then compressed to the cooler pressure. As the name suggests, these systems have a place with the general class of vapour cycles, wherein the working liquid refrigerant experiences stage change at any rate amid one. For the love of physics walter lewin may 16, 2011 duration. If, hypothetically, an open container of liquid r22 were placed in the frozen display case, when exposed to atmospheric pressure, it would absorb heat and boil violently at 41.
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