View and download powerpoint presentations on vapor compression refrigeration cycle ppt. The vapor compression refrigeration cycle is nearly 200 years old, but it does not seem ready to leave the scene any time soon. Cascade cycle is used where a very wide range of temperature between tl and th is. Vapour compression refrigeration system refrigeration vapour.
The main components there are four main components in a refrigeration system. The evaporator or low pressure, in the low side and the condenser, or high pressure. A refrigerator or heat pump that acts on the reversed carnot cycle is called a carnot refrigerator and carnot heat pump respectively. Of these, the reversed brayton cycle, which is also known as the gas refrigeration cycle. The operating principle of the refrigeration cycle was described mathematically by sadi carnot in 1824 as a heat engine. Vapor compression refrigeration cycle ppt xpowerpoint.
The vapor compression cycle explained is the most common type of system used in refrigeration. This video is an animation of how the refrigeration cycle. Ppt refrigeration basics 101 powerpoint presentation. 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. A simple and practical absorption system using ammonia as refrigerant and water as absorbent described in the previous articles is an example of singleeffect cycle system for vapour absorption refrigeration system. The gas flows through the compressor where its pressure and temperature becomes very high. The above figure shows the objectives of refrigerators and heat pumps.
By far the most common method of refrigeration is the vaporcompression refrigeration cycle a. A heat pump can be thought of as a heat engine which is operating in reverse. Remember refrigeration cycle diagram will always have the same basic components compressor, condenser, expansion device, evaporator, and refrigerant tube. Yeah, it seems complicated at first, but it will be easier to understand. The vapor compression refrigeration cycle is a common method for transferring heat from a low temperature to a high temperature. Jun 07, 2015 a fluid, known as a refrigerant, moves between four key stages in refrigeration cycle. The refrigeration cycle is a critical component of hvac systems and is governed by the principles of thermodynamics. Goals of lab to get acquainted with a vaporcompression refrigeration system to be able to use pressureenthalpy diagrams and.
The compressor the condensing coil the metering device the evaporator 3. One ton of refrigeration means amount of heat required to remove from one short ton of water at 00c to produce ice at 00c at 24 hours. The ideal vaporcompression cycle consists of four processes. To cool the refrigerant down it is passed through the expansion valve, this will reduce the pressure of the refrigerant by. Just as the vapors are used for cooling in the vapor compression cycle and vapor absorption cycle, the gas is used for cooling in gas refrigeration cycle. Thermodynamic system thermodynamic functions thermodynamic properties fundamental laws of. If an expander had been used the line from d to a would be a vertical line. Thermodynamics tutorial 5 heat pumps and refrigeration on completion of this tutorial you should be able to do the following. Compressor basic refrigeration cycle evaporator condenser receiver expansion device. Eric nelson basics refrigeration is the removal of heat from a material or space, so that it s temperature is lower than that of it s. Air is the most commonly used gas, also called as refrigerant in this case, in the gas refrigeration cycles. Refrigeration is used in many different residential, commercial, and industrial applications, ranging from food preservation to air conditioning to liquefaction of gases like oxygen and propane. Ph diagram representation of a dry refrigeration cycle.
In the process of being compressed the cool, gaseous refrigerant is turned to. Transfer heat from a cold space reservoir to a hot one. The five commercially available refrigeration cycles are. For an air conditioning system to operate with economy, the refrigerant must be used repeatedly. The refrigerant is a heat carrying medium which during their cycle in a refrigeration system absorbs heat from a low temp. Referring to the illustration below, beginning the cycle at the evaporator inlet 1, the lowpressure liquid expands, absorbs heat, and evaporates, changing to. Sep 23, 20 this is the beginning of the basic refrigeration cycle training. The vapour compression refrigeration cycle is classified as follows. The process is shown in a pressureenthalpy diagram. As refrigerant in the latent state or as vapor refrigerant in the process of changed state to liquid, this is the phase where it absorbs or rejects large quantities of heat. As it does so, it changes in pressure and temperature, this allows the fluid to absorb heat from one place and discharge it in another. Jun 25, 2003 mechanical refrigeration is accomplished by continuously circulating, evaporating, and condensing a fixed supply of refrigerant in a closed system. The bell coleman cycle also called as the joule or reverse brayton cycle is a refrigeration cycle where the working fluid is a gas that is compressed and expanded, but does not change phase. Ppt on vapor absorption refrigeration system ppt on vapor absorption refrigeration system.
Cycle with superheated vapor before compression, 5. Refrigeration cycle it is a well known fact that heat flows in the direction of decreasing temperature, i. Consider the real cycle taking place outside the two phase region using a compressor and an expander. Oct 12, 2012 this video is an animation of how the refrigeration cycle works, with each components function. Compression refrigeration cycle the vaporcompression refrigeration is the most widely used cycle for refrigerators, airconditioners, and heat pumps. In this video we look at how a refrigeration cycle works and use colour coding to see how the temperature and pressure changes throughout a. Heat pump and refrigeration cycles can be classified as vapor compression, vapor absorption, gas cycle, or stirling cycle types. Zubair latif comsats institute of information technology, lahore 2. Chapter 11 refrigeration cycles study guide in powerpoint to accompany thermodynamics.
The refrigeration cycle collects this heat by sending the refrigerant at a low temperature and pressure into the evaporator within that room. Hvac the refrigeration cycle hvac training for beginners. This rejection of heat from low level to higher level of temp. A refrigeration cycle explained involves the cooling system process of refrigerators and air conditioners. It is also used in domestic and commercial refrigerators, largescale warehouses for.
The vapor compression refrigeration cycle, step by step. In the following example, we will assume that the refrigerant being used is pure ammonia, which boils at 27 degrees f. Ppt refrigeration basics 101 powerpoint presentation free. Cycle with dry saturated vapour after compression, 2. The refrigerator in your kitchen uses a cycle that is similar to the one described in the previous section. This is what happens to keep the refrigerator cool. Liquids absorb heat when changed from liquid to gas. Article transcritical refrigeration systems with carbon dioxide co 2 danfoss as ra marketingmwa, july 2008 dkrci. The cooler refrigerant in the evaporator tubes, absorb the warm room air. The refrigeration cycle explained in plain english. Refrigeration cycle animation vapor compression cycle explained. Introduction a major application area of thermodynamics is refrigeration, which is the transfer of heat from a lower temperature region to a higher temperature one.
Bahrami ensc 461 s 11 refrigeration cycle 6 cascade refrigeration cycle systems that have 2 or more refrigeration cycles operating in series. Explains each step in a refrigeration cycle and the energy balance for each step. Two different pressures exist in the refrigeration cycle. A common alternate unit is the ton of refrigeration which equals 200 btumin or about 211 kjmin. At this stage in the refrigeration cycle, high pressure liquid refrigerant will flow down the liquid line, through a filter drier that is designed to prevent contaminants from flowing through the system, and on to the metering device. Vapor compression refrigeration system basic, working, parts of system introduction. Fundamentals of mechanical refrigeration systems course content introduction mechanical refrigeration is a thermodynamic process of removing heat from a lower temperature heat source or substance and transferring it to a higher temperature heat sink. The concepts of the refrigeration cycle is the same concept with a car air conditioner, your homes hvac and many other applications.
Mechanical refrigeration is accomplished by continuously circulating, evaporating, and condensing a. When 1 pound of ice melts, it absorbs 144 btu, as latent energy. Refrigeration cycle animation vapor compression cycle. Goals of lab to get acquainted with a vaporcompression refrigeration system to be able to use pressureenthalpy diagrams and tables to determine the c. So refrigeration cycle should be known to understand the refrigeration system. It is then throttled to the evaporator pressure and vaporizes as it absorbs heat from the refrigerated space. In the past, this was done by collecting ice in the winter and using its specific heat to cool as the ice melted. Basic refrigerator principle is reverse carnot cycle.
Air cycle refrigeration systems are employed for air conditioning the cockpit and cabin space of an airplane. Special university course for future engineers lecture notes. Vapor compression, absorption, gas cycle, steam jet and thermoelectric, of which the most popular is the vapor compression cycle. The compressor is widely considered the engine of the refrigeration cycle. In the first stage of this cycle process 12, the refrigerant absorbs heat. Ppt refrigeration free download as powerpoint presentation. 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.
Prove that this cycle is less efficient than the carnot cycle. Gases give off heat when changed from gas to liquid. The evaporator the evaporator is where the heat is removed from your house, business or refrigeration box. Purpose of refrigeration examples and applications choice of coolant and refrigerants phase diagram of water and co 2 vapor compression refrigeration system pressureenthalpy diagram for refrigerants refrigerator, air conditioner, thermoelectric cooler, heat pump designation, choice, criteria for selection, and. Of these, the reversed brayton cycle, which is also known as the gas refrigeration cycle, is used to cool aircraft and.
You could know the entire thing by knowing the pressure and temperature of. Refrigerators, heat pumps, acs cycles commonly classified as. Irreversibility includes pressure drops in lines and heat exchangers, heat transfer. Components and working of the gas refrigeration cycle.
But before i get into this hvac training i want to go over the three ways that heat can be transferred, and yes there are only 3 ways that heat can be. Transcritical refrigeration systems with carbon dioxide co. Refrigeration vaporcompression cycle online training. Vapour absorption refrigeration system with diagram. The basic refrigeration cycle for beginners if you are interested in learning how a refrigeration system works, it is helpful to understand from the ph pressure enthalpy chart perspective. These components may be in difference shape, capacity and size, but it does the same thing. Refrigeration cycle refrigeration is the transfer of heat from a lower temperature region to a higher temperature region refrigeration cycle is the vaporcompression refrigeration cycle, where the refrigerant is vaporized and condenses alternately and is compressed in the vapor phase.
Larger is the irreversibility in a refrigeration cycle operating with a given refrigeration load between two fixed temperature levels, larger is the amount of work required to operate the cycle. The components of the gas refrigeration cycle are very similar to the vapor compression cycle. The refrigeration cycles can also be represented in a ph diagram. Refrigeration cycle tutorial university of oklahoma. The refrigeration system is designed so that the refrigerant will evaporate in the evaporator at a temperature thats about 10 to 15 below the temperature setting if its a refrigerator or freezer, and the temperature will drop to around 0 in the evaporator of an ice machine or ice cream machine. It raises the pressure, temperature and enthalpy of the refrigerant by compressing the saturated gas, in an isentropic process, to a superheated. Prove that the area of inside the cycle plus the shaded. The schematic sketch of doubleeffect system is shown in fig. In todays lesson on hvac training i will be covering the refrigeration cycle and the 4 main components that make the cycle work. The compressor does work on the refrigeration system consumes energy.
Refrigeration cycle is the basis of all refrigeration systems. Devices that produce refrigeration are called refrigerators, and the cycles on which they operate are called refrigeration cycles. When this happens, it is called a reversed carnot cycle. When the gas is throttled from very high pressure to low pressure in the throttling valve, its temperature reduces suddenly while its enthalpy remains constant. Vars is also belongs to class of vapor cycle is similar to the vcrs. Air refrigeration systems authorstream presentation. Cycle with undercooling or subcooling of refrigerant. Some basic refrigeration cycles are discussed here through different diagrams. However, in vcrs mechanical work is required as input so it is called work operated cycle and unlike vcrs the required input in vars is low grade thermal energy so, called heat. The vapor compression refrigeration cycle is virtually rankine cycle with the only difference that. While some people have viewed this method as environmentally harmful and inefficient, the cycle is still applicable in the industrial sphere.
Wet refrigeration cycle the expander has been substituted by a throttling valve. The change of temperature causes the refrigerant to flash or boil, and changes from a low pressure liquid to a low pressure cold vapor. Refrigeration basics and lng university of oklahoma. Refrigeration cycles the vapor compression refrigeration cycle is a common method for transferring heat from a low temperature to a high temperature. Find powerpoint presentations and slides using the power of, find free presentations research about vapor compression refrigeration cycle ppt. If we understand how the refrigeration cycle works, well understand how any air conditioner works. The refrigeration cycle tells us if there is air in the central air conditioner units, what to repair after troubleshooting the refrigeration system, if there is enough air conditioner freon, or if the ac filter is dirty. Basic refrigeration cycle nina sri maulani 121624023 tptu 2012 2. For a refrigeration cycle to work, it requires five main components. Learning outcomes demonstrate understanding of basic vaporcompression refrigeration and heat pump systems. This video is part of the heating and cooling series of training videos made to accompany my websites. The purpose of a refrigerator is the removal of heat, called the cooling load, from a lowtemperature medium. A free powerpoint ppt presentation displayed as a flash slide show on id. Power and refrigeration cycles another look ppt presentation summary.
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