Refrigerant r22 vapour enters a positive displacement compressor at a slightly. The equations of exergetic efficiency and exergy destruction for the main system components such as compressor, condenser expansion device, liquidvapour heat exchanger and evaporator are developed. Refrigeration and air conditioning systems onboard ships vapour. There are many type of refrigeration system one of them is vapour absoption refrigeration system.
The refrigerant is let into and measured by a flow control device, and eventually released to the compressor. Vaporcompression refrigeration, in which the refrigerant undergoes. A computerized simulation of a simple singlestage vapourcompression refrigeration system has been made. Changes in mvr process chemistry, feed, throughput, seasonal, etc.
Performance evaluation of vapour compression refrigeration. Refrigeration and air conditioning pdf book agrimoon. 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. Vaporcompression evaporation is the evaporation method by which a blower, compressor or jet ejector is used to compress, and thus, increase the pressure of the vapor produced. During condensation, this thermal energy has to be dissipated again. It is a compression process, whose aim is to raise the refrigerant pressure, as it flows from an evaporator. Commonly used refrigerants for vapour compression chillers are chlorinated fluorocarbons cfcs, also called freons. Refrigerant r22 vapour enters a positive displacement compressor at a slightly superheated state 1 and is then compressed to state 2. Performance evaluation of vapour compression refrigeration system with three layer zig zag shaped evaporator. Tevs sensing bulb is placed near to the compressor suction where vapour is present in the supreheated form inside the l. In an ideal vapor compression refrigeration cycle, the refrigerant enters the compressor as a saturated vapor and is cooled to.
Vapour compression refrigeration system free download as powerpoint presentation. The vapor compression refrigeration cycle has four components. The refrigerant, while passing through the condenser, gives up its latent heat to the surrounding. Basics of vapour compression refrigeration system vcrs by mona yadav duration. On the condenser side, refrigeration system is used as a heat pump for heating applications such as process heating, drying etc. The vapor compression refrigeration cycle, step by step. The steadystate simulation uses the accurate property correlations developed by cleland. Fundamentals of mechanical refrigeration systems course content. Vapor absorption refrigeration cycle or vapor absorption refrigeration system vars pdf. Compressor 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 high pressure and temperature. This refrigeration system is different from compression refrigeration system. Vapor injection in scroll compressors purdue epubs.
The vapour produced is compressed by a mechanical compressor at 50 per cent efficiency and then returned to the calandria of the evaporator. The principle of the system is to make use of two substances that can be separated when heated. Compressor is said to the heart of the vapour compression system compresses the vapour refrigerant from the. Selection of a refrigerant for a vapour compression system depends on which among the following. Layout of the r22 vapourcompression refrigeration system. Vapor injection has also been employed with screw compressors, with an increase in both capacity and system cop. In compression refrigeration system we used a compressor which is run by electricity but absorption refrigeration system always runs by using a heat source. Vapour compression cycle free download as powerpoint presentation. Selection of a refrigerant for a vapour compression system.
The system is quiet in operation due to less number of moving parts. From the above expression, it can be seen that specific work input reduces as specific volume, v 1. Vapor compressor technologies products and services howden. These recommendations give a starting point for designing and building heat pump systems. The vapor compression refrigeration cycle involves four components. 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. Vapor compression refrigeration system basic, working, parts of system introduction. 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.
In the vapour absorption system, an absorber, a pump, a generator and a pressurereducing valve replace the compressor. The simplest explanation of this system is a heat engine working in reverse, technically referred to. Pdf in vapour compression refrigeration system, it generates fresh drinking water and also extracts water from humid ambient air by using. Vapour compression is a distillation process, where evaporation of sea or brackish water is obtained by the application of heat delivered by compressed vapour. The sub cooling increases refrigerating capacity whereas there is no change in compressor work. Working and mathematical analysis of above systems. This case study demonstrates the modeling of a vapour compression refrigeration system using r22 as refrigerant. And the libr being a salt has a recrystallization zone when it becomes solid and hence imposes flow. Pdf design and construction of a vapour compression. This is a pdf on the basic vapour compression cycle. Design of two stage vapour compression refrigeration. The vapor compression refrigeration cycle, step by step araner. Remaining cycle processes remain unchanged as shown. Refrigeration and air conditioning systems onboard ships.
Vapour compression refrigera tion system, refrigerant, ozone depletion, global warming, cfc. The vapour is drawn in the compressor cylinder at the condition of 1. Technology and applications gea engineering for a better. It is also used in domestic and commercial refrigerators, largescale warehouses for. Vapourcompression refrigeration or vaporcompression refrigeration system vcrs, in which.
It is also used in domestic and commercial refrigerators, largescale warehouses for chilled or frozen storage of foods and meats. Design of two stage vapour compression refrigeration system with water intercooler 1pravin d. The schematic diagram of the arrangement is as shown in fig. A single stage vapour compression refrigeration system has one low side. In which range of temperature the application of brine plants are made. This paper provides a detailed exergy analysis for theoretical vapour compression refrigeration cycle using r404a, r407c and r410a. 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. Review of vapour absorption refrigeration and vapour. Vapour compression refrigeration system slideshare. Vapor compression refrigeration system basic, working, parts of. Thus, in a vapour compression system, we must have a compressor which.
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. 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. In the absorption system, the compressor is replaced by the combination of an absorber, a generator, and a pump. The vapor compression refrigeration cycle is a common method for transferring heat. Refrigeration systems are also rated in terms of tons of refrigeration. By using the vapour produced as heat ing steam in a second effect, the energy requirement of the overall system will nearly halve. The vapour compression refrigeration system is by far the most popular and widely used system in refrigeration and air conditioning bot for industrial and domestic applications. In the proposed system the compressor work is less than compressor work of existing system. Download pdf lectures on vapour absorption refrigeration system.
Comparison of compound compression with single compressor system. In a vapor compression refrigeration system a gas refrigerant is alternatively compressed and expanded and goes from the liquid to the vapor state. Vapour compression cycle refrigeration atmospheric. The purpose of this document is to provide the heating scroll compressor users first selection of components for their refrigerant circuit using vapour injection. Nevertheless, system performance and reliable operation have to be verified by the. Refrigeration cycle l vapour compression refrigeration cycle l mechanical refrigeration cycle l mrc. Vocabulary background in the thermodynamics and refrigeration literature, several words are used interchangeably that can cause confusion. Vapour compression refrigeration system refrigeration heat. Work is supplied to the compressor during the isentropic compression 12 of refrigerant vapour from evaporator pressure pe to condenser pressure pc, and work. This is the part of the refrigeration system that is doing the actual cooling.
Vapour compression cycle definite guide with video. The vapour compression cycle which is used in vapour compression refrigeration system is nowadays used for all purpose refrigeration. The effect of compressing water vapour is obtained by means of an electrically driven, mechanical centrifugal compressor. The system has more weak, tear and noise due to moving parts in the compressor. Oil separator is not required in refrigeration system if. Power is supplied to the compressor and heat is added to the system in the. The design and construction of a refrigerator as a test rig, in investigating the performance of liquefied petroleum gas lpg, which has zero ozone depleting potential and very low global warming potential, as working fluid in vapour compression. First, evaporation is simply the process of vaporization these two terms are essentially synonymous. The analysis of the compressor dis discharge variation of physical properties and performance parameters of ii. A textbook of refrigeration and air conditioning simple vapour. System description the layout of the system is shown in figure 1. 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 compression refrigeration system generating fresh water from humidity in the air conference paper pdf available january 2011 with 4,091 reads how we measure reads.
Distilled water is produced from sea water by evaporation in a singleeffect evaporator working on the vapour compression system. Since the pressure increase of the vapor also generates an increase in the condensation temperature, the same vapor can serve as the heating medium for its mother liquid or solution being concentrated, from which the. Course content a vapor absorption chiller machine vam is a machine that produces chilled water. What are the commonly used refrigerants for vapour compression chillers. Typical vapor compression systems can be represented as shown in figure 5. The most common refrigeration system in use today involves the input of work from a compressor and uses the vapor compression cycle. Since in a compression system the energy consumption is related to mass flow, head and. Numericals on multievaporation and compression systems module 6.
Pdf vapour compression refrigeration system generating fresh. Simple vapour compression refrigeration system with. The prime energy consumer is the vapor compressor, accounting for over 80% of the total energy requirements. Refrigerants for vapour compression refrigeration systems. Beeton and pham 2003, describe successful implementation of the vi in scroll refrigeration systems using r404a. The saline water is evaporated at subatmospheric pressure. It is used for all industrial purposes from a small domestic refrigerator to a big air conditioning plant. The most widely used refrigeration cycle is the vapor compression refrigeration cycle. In the vapor absorption process, the compression process of the vapor compression cycle is replaced by an absorber, a generator and a pump. In this system, the working substance is a refrigerant like nh 3, r11, r12. A refrigeration system is a combination of components and equipment connected in a sequential order to produce the refrigeration effect. Both a steadystate and a transient simulation will be considered. Pdf vapour compression refrigeration system generating.
371 295 424 531 1206 343 1560 415 1584 1522 1112 932 795 545 73 425 780 964 1037 432 697 1495 1038 160 1301 1186 148 1229 331 1473 782