Software solutions, and contains three chapters, viz. A heat pump that operates on the ideal vapor compression. The actual cycle moved into the superheated vapour region of the graph much more than the actual cycle, meaning that more heat was rejected to the environment than expected. Chapter 105 the ph diagram is another convenient diagram often used to illustrate the refrigeration cycle. The design is to be based upon the ideal vapor compression refrigeration cycle, with four components. A refrigerator uses refrigerant4a as the working fluid and operates on an ideal vaporcompression refrigeration cycle between 0. Discuss temperatureentropy ts and pressureenthalpy ph property diagrams for vapor compression refrigeration system. The ts diagram for a vaporcompression refrigeration cycle is shown below. Expansion under throttling process, isenthalpic process process 4. Figure 15 refrigeration cycle on the ph diagram take the structure image of this refrigeration cycle from figure 15, it becomes the ph diagram for engineering calculation as shown in figure 16. The ts diagram for a vaporcompression refrigeration cycle is.
How can i design a vapor compression refrigeration cycle. Jsrae, japanese society for refrigerating and airconditioning. R1270, r32, r22, and r152a, in vapor compression refrigeration cycles and heat pumps was investigated. Chapter 10 refrigeration cycles 103 ideal and actual vapor compression cycles 104c yes. Schematic representation and ts diagram for ideal vapor compression cycle cengel, 2009. Chapter 10 refrigeration cycles 104 1011 an ideal vaporcompression refrigeration cycle with refrigerant4a as the working fluid is considered.
Constant pressure heat addition process ph diagram of ideal refrigeration cycle. The points which are required for engineering calculation are from h 1 to h 6 as shown in the figure 16. The above discussion is based on the ideal vapor compression refrigeration cycle which does not take into account real world items like frictional pressure drop in the system, slight internal irreversibility during the compression of the refrigerant vapor, or non ideal gas behavior if any. When you can draw a refrigeration cycle on a ph diagram, you can easily obtain the refrigerant characteristics through the diagram. With these assumptions the ideal vapor compression cycle.
The ideal refrigeration system is based on the concept of the reversible carnot cycle. A refrigerator uses refrigerant4a as the working fluid and. A comparison between refrigerants used in air conditioning. The above discussion is based on the ideal vaporcompression refrigeration cycle which does not take into account real world items like frictional pressure drop in the system, slight internal irreversibility during the compression of the refrigerant vapor, or nonideal gas behavior if any. This figure represents, schematically, the extraction of heat at rate from a cold body at temperature t c. Thermodynamics i learncheme educational resources for. Process 12 process 23 process 34 process 41 mech 337 thermodynamics class notes page. A common alternate unit is the ton of refrigeration which equals 200 btumin or about 211 kjmin. An ideal vapor compression refrigeration cycle ope. Under refrigeration cycles, following cycles are analyzed.
The ph and ts diagram for the simple vapor compression refrigeration cycle is shown in the figure for vapour entering the compressor is in dry saturation condition the dry and saturated vapour entering the compressor at point 1 that vapour compresses isentropic ally from point 1 to 2 which increases the pressure from evaporator pressure to condenser. The refrigeration effect for this cycle may be defined as the heat removed from the makeup gas in order to turn into a liquid at state 6. The refrigerant cycle was plotted on a ph diagram, showing the ideal and actual cycle along with irreversibilities. Refrigeration system an overview sciencedirect topics. Show the cycle on a ts diagram with respect to saturation lines. The rate of heat removal from the refrigerated space, the power input to the compressor, the rate of heat rejection. A heat pump that operates on the ideal vapor compression cy. Vaporcompression refrigeration cycle interactive simulation. Learn how to draw a cycle for ideal conditions on a ph chart. Mar 10, 2016 homework equations na the attempt at a solution i am trying to understand the above ph diagram for a vapour compression cycle, in some examples, point 1 is situated as above in the image i. A heat pump can be thought of as a heat engine which is operating in reverse. Simulations whose names are in blue will play in most browsers, but most were programmed in mathematica, and the cdf versions, which can be downloaded, are significantly faster and can be used offline with the wolfram cdf plugin. Download scientific diagram ideal vapour compression refrigeration cycle in ph. Vapour compression cycle understanding refrigeration.
Thermodynamics seventh edition covers the basic principles of thermodynamics while presenting a wealth of realworld engineering examples so students get a feel for how thermodynamics is applied in engineering practice. Jan 30, 2014 learn how to draw a cycle for ideal conditions on a ph chart. Vapour compression refrigeration cycle simulator operating parameters. The purpose of a refrigerator is the removal of heat, called the cooling load, from a lowtemperature medium. In an ideal cycle, the refrigerant vapor would enter the compressor as a saturated vaporno superheat. Refrigeration cycle for ideal conditions on a pressure. Property diagrams ts and ph for refrigeration 2 youtube. The process requires the expenditure of work w and the sum is discharged at a higher temperature t h. Refprop software was applied to capture the thermodynamic properties of. Show the cycle on a ts diagram with respect to the saturation lines. The design is to be based upon the ideal vaporcompression refrigeration cycle, with four components. A refrigerator uses refrigerant4a as the working fluid and operates on an ideal vapor compression refrigeration cycle between 0. With these assumptions, the ideal vapor compression cycle is as follows.
The vaporcompression cycle is a popular type of refrigeration cycles. Efficiency or cop the conventional way to express the effectiveness of refrigeration is coefficient of performance cop. Analysis a in an ideal vaporcompression refrigeration cycle, the compression process is isentropic, the refrigerant enters the compressor as a saturated vapor at the evaporator pressure, and leaves the condenser as saturated liquid at the condenser pressure. The most frequently used refrigeration cyclic is the vaporcompression refrigeration cycle. So in preliminary cycle calculations pressureenthalpy diagrams are particularly useful. Thermodynamic analysis of vapor absorption refrigeration. Ideal and actual vapour compression cycle, ideal and actual reversed brayton cycle or. This template uses r4a as the working fluid, but can be readily changed to another refrigerant. A heat pump operates on the ideal vapor compression refrigeration cycle with r4a as the working fluid between the pressure limits of 0. The vapor compression refrigeration cycle is nearly 200 years old, but it does not seem ready to leave the scene any time soon. P, t, h, and phase changes in a vapor compression refrigeration cycle 2. In an ideal evaporator, there is just enough heat transfer to convert all the.
Goals of lab to get acquainted with a vaporcompression refrigeration system. In other words a small amount of liquid circulating in a refrigerator can perform a large amount of cooling. The process of refrigeration can be easily described in ph diagram. Most of the differences between the ideal and the actual cycles are because of the irreversibilities in various components which are. A heat pump operates on the ideal vapor compressio. We want to design a vapor compression refrigeration cycle to absorb heat from a cool environment and reject it to a warm environment. An explanation of the ph diagram, practical refrigeration cycle, evaporation and condensation is in the the understanding refrigeration pages. Process 12 isentropic compression in low temperature compressor.
Ideal vapour compression refrigeration cycle in ph diagram. Determine a the rate of heat removal from the refrigerated space and power input to the compressor, b the rate of heat. Its even ok if the compressor feed is slightly superheated. You can get basic information about your vapor compression refrigeration cycle from the. The ideal vapour compression cycle consists of two constant pressure process and one constant enthalpy process. The cycle efficiency and operation characteristics of an absorption refrigeration system depend on the properties of refrigerant, absorbent andtheir mixtures. An explanation of the p h diagram, practical refrigeration cycle, evaporation and condensation is in the the understanding refrigeration pages. Ph diagram for a vapour compression cycle physics forums. The ideal cycle if the operating temperatures and pressures are known, the refrigeration system can be plotted on the ph diagram.
On the basis of this knowledge, our software for refrigeration equipment displays the respective log ph diagram in real time. Refrigeration effect an overview sciencedirect topics. Analyses was made on the ideal vapor compression refrigeration cycle and a second cycle which was created by adding subcool and superheat regions on the first one. Each stage operates on an ideal vapor compression refrigeration cycle with refrigerant4a as the working fluid. Dec 01, 2016 the refrigerant cycle was plotted on a p h diagram, showing the ideal and actual cycle along with irreversibilities. When you can draw a refrigeration cycle on a p h diagram, you can easily obtain the refrigerant characteristics through the diagram. The above figure shows the objectives of refrigerators and heat pumps. The operating principle of the refrigeration cycle was described mathematically by sadi carnot in 1824 as a heat engine.
This program permits the design, sizing, analysis and optimization of refrigeration cycles. Lets study about how to draw a refrigerant cycle in series, using the documents with courtesy of mr. Vaporcompression refrigeration cycle new 522018 the vaporcompression refrigeration cycle is analogous to the rankine cycle, but runs in the opposite direction counterclockwise on the ts diagram vs. Ph diagram of an ideal vaporcompression refrigeration cycle fig. The condenser and evaporator pressures are 1400 and 320 kpa, respectively. The performance of refrigeration plant is expressed as coefficient of performance cop which is defined as the ratio of refrigerating effect produced to the work of compression.
Ideal vaporcompression refrigeration cycle process description 12 isentropic compression 23 constant pressure heat rejection in the condenser 34 throttling in an expansion valve 41 constant pressure heat addition in the evaporator. Srikanta biswas, roll no11800712053 biplab khan, roll no11800767 somnath dey, roll no11800712051 sayan sarbajna, roll no11800712049 shovan ghosh, roll no11800712050 surovita santra, roll no 11800777 guided. H 1 h f based on temperature at d exit of condenser h 2 h g. This is the ratio of heat extraction to energy input. The vapor compression refrigeration cycle, step by step. Heat pump and refrigeration cycles can be classified as vapor compression, vapor absorption, gas cycle, or stirling cycle types. Calculate a the power input to the compressor, in kw. With these assumptions the ideal vapor compression cycle is. A basic system is composed of a condenser, an evaporator, a compressor and an expansion valve plus auxiliary and connection components. Explain vapour compression refrigeration cycle on ts and. Ph diagram thermodynamics hvac and refrigeration pe exam. Maximum efficiency of the vapour compression cycle it takes a lot of heat to evaporate liquid. Heat rejection from the lower cycle to the upper cycle takes place in an.
It consists of evaporator, compressor, condenser and thermal expansion valve figure 1. Mar 14, 2016 the cycle that results is called the ideal vapor compression refrigeration cycle, and it is shown schematically and on a ts diagram in fig. Refrigeration cycle for ideal conditions on a pressure enthalpy chart. Refrigeration cycle is the basis of all refrigeration systems. If you have any doubt then feel free to ask in the comment box. Vapor compression refrigeration cycle new 522018 the vapor compression refrigeration cycle is analogous to the rankine cycle, but runs in the opposite direction counterclockwise on the ts diagram vs. Refrigeration cycles the vapor compression refrigeration cycle is a common method for transferring heat from a low temperature to a high temperature.
This case is also to evaluate various cycles such as with penalties, economizing for a single stage compression refrigeration systems which are based on the same ct, et and tr as the following. Saturated vapor enters the compressor at 2 bar, and saturated liquid exists the condenser at 8 bar. Ch 10, lesson b, page 2 the ideal vaporcompression refrigeration cycle. Changes to operating parameters can be read directly in the diagram and allow a valuable insight into the formation of the thermodynamic states, which otherwise can only be appreciated statically. Performance analysis of vapour compression refrigeration system with r404a, r407c and r410a jyoti soni 1 and r c gupta corresponding author. This is because the latter cycle involves an irreversible process for which the process path is not known. An ideal vapor compression refrigeration cycle operates at a steady state with refrigerant 4a as the working fluid. Mechanical refrigeration processes, of which the vapor compression cycle is an example, belong to the general class of reversed heat engine cycles, figure 1. Refrigeration cycles, air compressors and thermodynamic relations. Some basic refrigeration cycles are discussed here through different diagrams. Natural gas plants, petroleum refineries, and petrochemical plan. Exergy analysis of vapour compression refrigeration system.
So refrigeration cycle should be known to understand the refrigeration system. A thermodynamic refrigeration cycle removes heat from a lowtemperature object refrigeration and rejects it at a higher temperature. This is one reason why the vapour compression cycle is widely. Analysis a in an ideal vapor compression refrigeration cycle, the compression process is isentropic, the refrigerant enters the compressor as a saturated vapor at the evaporator pressure, and leaves the condenser as saturated liquid at the condenser pressure. A heat pump that operates on the ideal vapor compression cycle with refrigerant4a is used to heat a house. Efficiency or cop the conventional way to express the effectiveness of refrigeration is coefficient of performance. Most simulations are also available at wolfram demonstration project. Actual vapourcompression cycle two main differences with ideal cycle. Homework equations na the attempt at a solution i am trying to understand the above ph diagram for a vapour compression cycle, in some examples, point 1 is situated as above in the image i. Your feedback and comments is important to me in developing.
Exergy analysis of vapour compression refrigeration system using r 4a. Oct 22, 2016 how to solve vapour compression refrigeration cycle based problem. The program includes the option to optimize refrigerant circuitry in the heat. Rac hindi l 03 vapour compression refrigeration cycle.
The quiz simulations follow a stepbystep procedure that requires user input. Cengel and boles 1998 the vapor compression refrigeration system is the most common refrigerationsystem that is being used nowadays. Please provide feedback on this module by selecting like or dislike. We want to design a vaporcompression refrigeration cycle to absorb heat from a cool environment and reject it to a warm environment. Chapter 10 refrigeration cycles ideal and actual vapor. This is one reason why the vapour compression cycle is widely used. Case1 the basics of refrigeration cycle ph diagram analysis. The cycle that results is called the ideal vapor compression refrigeration cycle, and it is shown schematically and on a ts diagram in fig. While some people have viewed this method as environmentally harmful and inefficient, the cycle is still applicable in the industrial sphere.
The easiest way to improve the quality of the feed to the compressor is to make sure that the evaporator completely vaporizes the working fluid. An ideal refrigeration cycle looks much like a reversed carnot heat engine or. The vaporcompression refrigeration cycle is the most widely used cycle for refrigerators, airconditioning systems, and heat pumps. Four processes of the ideal vapor compression refrigeration cycle the ideal vaporcompression refrigeration cycle process description 12 isentropic compression 23 constant pressure heat rejection. Consider a twostage cascade refrigeration system operating between the pressure limits of 0.
1579 992 1390 604 135 543 1200 1562 141 1196 1238 181 674 249 272 497 1337 157 1148 1419 73 726 259 1178 803 701 1046 306 819 248 1514 376 1392 250 930 1230 1124 414 896 1150 697 420 266