The cannot coefficient of performance of cycle will be a 0. The compressors are one of the most important parts of the refrigeration cycle. Rev pages chapter 9 refrigerants, refrigeration cycles, and. Firstlesson on how the basic refrigeration cycle works the refrigeration cycle explains to us what is happening to the ac freon in each of the four components within the air conditioner units. Sunlight goes source to an through a window absorbent surface without heating the space in through a window without heating the glass but heats the the space in s rface in the room between. Also covered in this chapter are the methods used for installing, maintaining, and repairing refrigeration equipment, including domestic refrigerators and freezers. The refrigeration cycle explained in plain english. The challenge in refrigeration and air conditioning is to remove heat from a low temperature source and dump it at a higher temperature sink.
In a refrigeration cycle, the flow of refrigerant is controlled by a compressor b condense. May 15, 2018 the most widely used refrigeration cycle method is mechanical compression. The trane air conditioning clinic series is one means of knowledge sharing. So refrigeration cycle should be known to understand the refrigeration system.
Main parts of vapor compression refrigeration cycles. The absorption refrigeration cycle is an alternative that absorbs the refrigerant in a liquid solution rather than evaporating it. Study 72 terms basic refrigeration questions flashcards. Compressor types this period is devoted to the discussion of the different types of compressors. The compressor does work on the refrigeration system consumes energy. Energy in the form of heat is removed from a lowtemperature reservoir and transferred to a hightemperature reservoir. Bahrami ensc 461 s 11 refrigeration cycle 6 cascade refrigeration cycle systems that have 2 or more refrigeration cycles operating in series.
In other words, refrigeration is artificial humanmade cooling. Pdf a conventional refrigeration cycle uses expansion device between the condenser and the evaporator which has losses. 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. However, first lets understand air conditioning theory, the basic principle, types of heat, how heat transfers and i will show you how the basic refrigeration cycle diagram works. Thermodynamic heat pump cycles or refrigeration cycles are the conceptual and mathematical models for heat pumps and refrigerators. It has applications in both air conditioning and commercial and industrial refrigeration. A heat pump is a mechanical system that allows for the transference of heat from one location the source at a lower temperature to another location the sink or heat sink at a higher temperature. Request pdf simulation studies of refrigeration cycles. Your customers may not need to go beyond this simple understanding of refrigeration. 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.
The operating principle of the refrigeration cycle was described mathematically by sadi carnot in 1824 as a heat engine. The refrigeration cycles can also be represented in a ph diagram. Pdf analysis of refrigeration cycle performance with an ejector. Refrigeration systems operate on a series of consecutive thermodynamic processes that form a cycle that returns the working substance to the same state. Refrigeration is the process of heat removal from a low temperature sink and added to a high temperature reservoir to. Cops for the three types of co2 refrigeration cycles correspond to a. Refrigeration is a process of cooling or remove heat to lower the temperature of a space, or items to be stored in the space, to a temperature below the temperature of the surrounding area. The absorption refrigeration cycle is the subject of a separate clinic. However, they may expect you to have a much greater indepth understanding of refrigeration to help them solve their cooling needs. The most common types of refrigeration systems use the reverserankine vaporcompression refrigeration cycle, although absorption heat pumps are used in a minority of applications. There are various types of compressors used in the refrigeration and air conditioning machines, these are.
A heat pump can be thought of as a heat engine which is operating in reverse. All air conditioner units must have the five basic components to work. There are primarily four types of compressors used in the airconditioning industry. Two different pressures exist in the refrigeration cycle. As a result, it can be used in different industries such as building, refrigeration, mining, metallurgy, etc. The compressor compresses the refrigerant, which flows to the condenser, where it gets cooled. As the name suggests, these types of systems transfer heat by mechanically compressing refrigerant into a lowpressure, cold liquid and expanding it into a highpressure, hot gas. Oct 12, 2012 this video is an animation of how the refrigeration cycle works, with each components function. Refrigeration cycle it is a well known fact that heat flows in the direction of decreasing temperature, i. 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. Multiple choice questions with answers on refrigeration and.
Refrigeration and air conditioning objective questions and answers pdf. Principles of refrigeration pdf boilersinfo refrigeration cycle evaporator condenser receiver expansion device. Th movement cooling by the removal of heat the movement of heat from a place where it is notot a ted to a. 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. 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. The above figure shows the objectives of refrigerators and heat pumps. In reefer ships, the temperature of the perishable or temperature sensitive cargo such as food, chemical, or liquefied gas, is controlled by the refrigeration plant of the ship. Air conditioning clinic refrigeration cycle one of the. Now in liquid form at high pressure, the refrigerant cools down as it flows into the coils inside the. The refrigeration plants on merchant vessels play a vital part in carrying refrigerated cargo and provisions for the crew on board. The two main types of hazardous refrigerants used in vessel. A refrigeration carnot type cycle based on isothermal compression and two reversible expansions is proposed. Compression refrigeration cycles in general take advantage of the idea that highly compressed fluids at one temperature will tend to. Two principle types of refrigeration plants found in industrial use are.
This is accomplished by using a mechanical refrigeration process in which a refrigerant is used to alternately absorb heat from the space or object to be. Refrigeration system an overview sciencedirect topics. However, the material covered and the method of presentation are such that the text is also suitable for adult evening classes and for onthejob training and selfinstruction. Refrigeration cycles the vapor compression refrigeration cycle is a common method for transferring heat from a low temperature to a high temperature. It tells us how much refrigerant the evaporator absorbs, the refrigerant properties in the compressor, and how much refrigerant the condenser rejects. The copper refrigerant tube a tube that connects these air conditioner parts well be discussing the ac cycle from splitcentral air conditioner units perspective.
It raises the pressure, temperature and enthalpy of the refrigerant by compressing the saturated gas, in an isentropic process, to a superheated. Cascade cycle is used where a very wide range of temperature between tl and th is. Selecting the right refrigerant there are several types of refrigerants such as cfcs, ammonia, hydrocarbons. Gas refrigeration cycles include the reversed brayton cycle and the hampsonlinde cycle. Ppt refrigeration basics 101 powerpoint presentation free.
Refrigeration onboard ships marine engineering study. The copper refrigerant tube a tube that connects these air conditioner parts well be discussing the ac cycle from splitcentral air. 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. It has applications in both air conditioning and commercial and. It is lighter than air and has a sharp, pungent odor that serves as a warning of its presence. As a result, it can be used in different industries such as building, refrigeration.
When the hot gas in the coils meets the cooler air temperature of the kitchen, it becomes a liquid. The compressor the condensing coil the metering device the evaporator 3. This liquid can then be circulated through a heat exchanger to cool air or equipment as required. An absorption refrigerator is a refrigerator that uses a heat source e. There are two basic types of absorption refrigeration cycle the lithium bromide. This video is an animation of how the refrigeration cycle. Refrigeration basics and lng university of oklahoma. 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 place where it is unobjectionable. Ppt refrigeration basics 101 powerpoint presentation. The four types of refrigeration systems you need to know.
A chiller is a machine that removes heat from a liquid via a vaporcompression or absorption refrigeration cycle. Wet refrigeration cycle the expander has been substituted by a throttling valve. Its function is to provide a heat transfer surface through which heat can pass from the refrigerated space into the vaporizing refrigerant. 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.
During the compression cycle, the refrigerant passes through four major. The purpose of a refrigerator is the removal of heat, called the cooling load, from a lowtemperature medium. 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. The refrigeration cycle tells us if there is air in the central air conditioner units, what to repair after troubleshooting. An ejectorexpansion refrigeration cycle using nitrous oxide. This involves absorption of heat at a lower temperature and rejection to higher temperature of the surroundings. Hvac and refrigeration system bureau of energy efficiency 73 figure 4. Although ideal, this cycle is close to a realistic one which could be designed with. A free powerpoint ppt presentation displayed as a flash slide show on id.
Materials as printouts and additionally also as pdf files. Oct 19, 2019 the refrigeration plants on merchant vessels play a vital part in carrying refrigerated cargo and provisions for the crew on board. The traditional reciprocating compressor has been used in the industry for decades. The main components there are four main components in a refrigeration system. This cyclic process requires that work be input so that. Refrigeration fundamentals heatcraft worldwide refrigeration. This video is an animation of how the refrigeration cycle works, with each components function.
Basic refrigeration cycle nina sri maulani 121624023 tptu 2012 2. If an expander had been used the line from d to a would be a vertical line. Just a short video explaining the basics of how most refrigeration systems operate. This book has been written especially for use in programs where a full curriculum in refrigeration is offered. Perform various cycle calculations for different types of refrigerants section. Refrigeration cycle tutorial university of oklahoma. Refrigeration cycle is the basis of all refrigeration systems.
Applications of refrigeration and air conditioning. Hazards during the repair and maintenance of refrigeration. Zubair latif comsats institute of information technology, lahore 2. A thermodynamic refrigeration cycle removes heat from a lowtemperature object refrigeration and rejects it at a higher temperature. Industrial refrigeration and cooling invest northern ireland. Multiple choice questions on refrigeration and air. This is a refrigeration cycle diagram of regular central air conditioner units. Some basic refrigeration cycles are discussed here through different diagrams. A refrigeration cycle, b vapour cycle, p1 pressure in the evaporator. The illustration above is a consumers understanding of refrigeration. Refrigeration is a process that removes heat from a space, substance, or system to lower andor maintain its temperature below the ambient temperature. Hazards during the repair and maintenance of refrigeration systems on vessels the repair and maintenance of refrigeration systems can present hazards to both workers servicing these systems and those in the general area.
Which of the following is not a desirable property of a. In reefer ships, the temperature of the perishable or temperature sensitive cargo such as food, chemical, or liquefied gas, is controlled by the refrigeration. Ph diagram representation of a dry refrigeration cycle. Multiple choice questions with answers on refrigeration and airconditioning set 07 practice test. The system uses two coolants, the first of which performs evaporative cooling and is then absorbed into the second. While ammonia is a relatively toxic substance, it is not a cumulative poison. Different types of main components such as compressors, evaporators and condensers, as well. Jul 03, 2017 refrigeration deals with cooling of bodies or fluids to temperatures lower than those of surroundings. The vapor compression refrigeration cycle is a common method for transferring heat from a low temperature to a high temperature. Multiple choice questions with answers on refrigeration. Heat pump and refrigeration cycles can be classified as vapor compression, vapor absorption, gas cycle, or stirling cycle types. Vapor compression refrigeration system basic, working.
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