Refrigeration may be defined as a process of removing heat from a substance and pumping it to the surroundings. Refrigeration and air conditioning systems onboard ships vapour compression systems moving heat from a lower temperature to higher temperature requires work to be done, according to second law of thermodynamics and this work can be done in many ways in different systems. The required refrigeration capacity of a vapour compression refrigeration system with r22 as refrigerant is 100 kw at 30oc evaporator temperature. A compressor which compresses the vaporous working fluid. Alka bani agrawal et al 8 worked on ecofriendly refrigerant as a substitute for cfc chlorofluorocarbon. First, evaporation is simply the process of vaporization these two terms are essentially synonymous. Refrigerant r22 vapour enters a positive displacement compressor at a slightly superheated state 1 and is then compressed to state. Subcooling in refrigeration implies cooling the refrigerant in liquid state, at uniform pressure, to a temperature that is less than the saturation. The low temperature, low pressure vapour at state b is compressed by the compressor.
The temperature at which a fluid boils or condenses is known as. Various modifications since the start of the new century has reflected the tremendous change in the coefficient of performance vapour compression refrigeration systems. Most of the domestic refrigerators work on the following refrigeration system a vapour compression b vapour absorption c carnot cycle d electrolux refrigerator e dual cycle. Refrigeration and air conditioning pdf book agrimoon. Vapour compression refrigeration is the primary method to provide mechanical cooling. A performance comparison of vapour compression refrigeration system using eco friendly refrigerants of low global warming potential a. Performance analysis of vapour compression and vapour. The schematic diagram of the arrangement is shown in fig. Refrigerants for vapour compression refrigeration systems. Vaporcompression refrigeration is a refrigeration system that uses a circulating liquid refrigerant to absorb and remove heat from a space that needs cooling. Heat rejection from the lower cycle to the upper cycle takes place in an. Ts and ph diagrams for an ideal vaporcompression refrigeration cycle.
Initially the system was singlestage with a single compressor compressing the refrigerant vapour from evaporator to. Refrigeration onboard ships marine engineering study. The above figure shows the objectives of refrigerators and heat pumps. Vapour compression systems have mainly four elements in the refrigeration system i. The standard vapour compression refrigeration system section 10.
Refrigeration cycles the vapor compression refrigeration cycle is a common method for transferring heat from a low temperature to a high temperature. This course is an overview of vaporcompression refrigeration cycle, principles of heat generation, transfer and rejection. 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, step by step. Pdf exergy analysis of vapour compression refrigeration. Schematic of a vapour compression refrigeration cycle is shown in fig. For 30 years, topics such as air refrigeration cycles and systems, vapour compression refrigeration systems simple and compound, refrigerants incl. The primary difference is in the manner in which heat is utilized. This is an important advantage as against the conventional vapour251compression system which operates on high grade energy. The saturated vapor at state 1 is superheated to state 2. A vapour compression refrigeration system comprises of four components. Pdf vapour compression refrigeration system generating. Refrigeration and air conditioning systems onboard ships. Download pdf lectures on vapour absorption refrigeration system.
The vapor compression refrigeration cycle is nearly 200 years old, but it does not seem ready to leave the scene any time soon. System description the layout of the system is shown in figure 1. Compressors, psychrometry and applications of refrigeration and air conditioning have been included and updated for students to conceptualise the subject in a complete manner. At point 1, let t 1, p 1 and s 1 be the temperature, pressure and entropy of the vapour refrigerant. In a vapour compression refrigeration system, the compressor plays a key role on the power consumption and its overall performance is a result of electrical, mechanical and thermodynamic efficiencies. Vapour absorption system vapour absorption system is an attractive method for utilizing low grade energy directly for cooling. Refrigeration is the extraction of heat, or the transmission of heat by mechanical methods, from one location to another. In any refrigeration process, heat is transferred from one region to another with the aid of an external agent. The absorption was the predecessor of the vapour compression system in 19th century and aqua ammonia system enjoyed wide applications in domestic refrigerators and large industrial installations in the chemical and process. The general rule for rating refrigeration systems excepting for c02 system. Vapour compression cycle definite guide with video. It is also used in domestic and commercial refrigerators, largescale warehouses for. College of engineering and technology, pollachi 642002, india.
It is also used in domestic and commercial refrigerators, largescale warehouses for chilled or frozen storage of foods and meats. Vapour compression refrigeration system refrigeration heat. It also includes the process of maintaining and reducing the temperature of a body below the general temperature of its surroundings. Experimental analysis on vapour compression refrigeration vcr system with r4a tetra fluro ethane refrigerant. Exergy analysis of vapour compression refrigeration system article pdf available in international journal of applied engineering research 412. The vapour compression refrigeration system is an improved type of air refrigeration system using a liquid refrigerant as medium. Vapor compression refrigeration system basic, working, parts of system introduction. A simple vapour compression system of refrigeration consists of the equipment as follows. A vapour absorption system utilizes the lowgrade form of heat energy to produce cold. The binary mixture in the ration of 64% and 36% of r290 and r600a found to be a retrofit or drop in substitute of r12 for use in the vapour compression refrigeration trainer. A reversible, adiabatic isentropic compression of the refrigerant. A vapour compression refrigeration system is an improved type of air refrigeration system in which a suitable working substance, termed as refrigerant is used. Vapor compression refrigeration system basic, working.
The refrigeration capacity is 8 tr and the compression is. Recommended book for hvac engineers details and easy understanding refrigeration and air conditioning concepts are there in this. Basic refrigeration cycle and concepts, standard rating of refrigerating machines lesson 2. Vapour compression refrigeration system free download as powerpoint presentation. Joshi 1 department of mechanical engineering, walchand college of engineering, sangli 416415, maharashtra, india abstract refrigeration is the process of reducing and maintaining the temperature of a space or material below the. A textbook of refrigeration and air conditioning simple vapour. It condenses and evaporates at temperatures and pressures close to the atmospheric conditions. 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. The refrigerant used does not leave the system but is circulated throughout the system. Actual vapour power cycle in hindi lecture5 duration. Pdf vapour compression refrigeration system generating fresh. This vapour compression system mainly consists of a refrigerator compressor, a liquid compressor, a liquid receiver, a refrigerant control valve also called as an expansion valve and evaporator vapour absorption refrigeration system. Design of two stage vapour compression refrigeration system with water intercooler 1pravin d. Vapour compression refrigera tion system, refrigerant, ozone depletion, global warming, cfc.
Layout of the r22 vapourcompression refrigeration system. These are the evaporator, condenser, compressor and the. The vapor usually leaves the evaporator is superheated to prevent droplet of liquid within the compressor. Simple vapour compression refrigeration system with. One of the common refrigeration systems in use today is the vapor compression cycle. By araner posted 20180223 in refrigeration the vapor compression refrigeration cycle is nearly 200 years old, but it does not seem ready to leave the scene any time soon. Koshy mathews2 1 department of mechanical engineering, p. The vapor compression refrigeration cycle, step by step araner.
Consider a twostage cascade refrigeration system operating between the pressure limits of 0. The actual vapour compression cycle differs from the standard cycle due to the following reasons. Numerical simulation of vapour compression refrigeration. Vocabulary background in the thermodynamics and refrigeration literature, several words are used interchangeably that can cause confusion. The vapor compression refrigeration cycle involves four components. In vapour compression refrigeration cycle an exery analysis of vapour compression refrigeration system 2507 exergy analysis can be used to identify which. Pdf exergy analysis of vapour compression refrigeration system. All vapor compression systems consist of the following four basic components alongwith the interconnecting piping. Pdf textbook of refrigeration and airconditioning by r. The vapor compression refrigeration system is the most widely used refrigeration system today for air conditioning of large public buildings, private residences, hotels, hospitals, theaters, restaurants, and a host of other services. The low pressure and temperature vapour refrigerant from evaporator is drawn into the compressor through the inlet or suction valve a, where it is compressed to a. The purpose of a refrigerator is the removal of heat, called the cooling load, from a lowtemperature medium.
Both a steadystate and a transient simulation will be considered. This case study demonstrates the modeling of a vapour compression refrigeration system using r22 as refrigerant. Review of vapour absorption refrigeration and vapour. Refrigerant r22 vapour enters a positive displacement compressor at a slightly. Robertson, phillips, and the history of the screwdriver duration. The vapor compression refrigeration cycle is a common method for transferring heat from a low temperature to a high temperature. The most common refrigeration system in use today involves the input of work from a compressor and uses the vapor compression cycle. Hvac and refrigeration system bureau of energy efficiency 73 figure 4. Schematic of a basic vapor compression refrigeration system it can be seen that the condenser has to be capable of rejecting the combined heat inputs of the evaporator and the compressor. Multistage vapour compression refrigeration example1 two stage compression system with water intercooler uses r4a as shown in figure1. To improve the coefficient of performance cop, it is require decreasing the compressor work and increasing the refrigerating effect. This approach involves the operation of a vapor compression refrigeration cycle to induce heat to travel in a direction contrary to gross environmental. Before we discuss subcooling and super heating, it is essential to understand what refrigeration is. Subcooling and superheating in industrial refrigeration.
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