Refrigeration cycle it is a well known fact that heat flows in the direction of decreasing temperature, i. This video is an animation of how the refrigeration cycle works, with each components function. However, they may expect you to have a much greater indepth understanding of refrigeration to help them solve their cooling needs. Vapor compression refrigeration system basic, working. When the hot gas in the coils meets the cooler air temperature of the kitchen, it becomes a liquid. Bahrami ensc 461 s 11 refrigeration cycle 6 cascade refrigeration cycle systems that have 2 or more refrigeration cycles operating in series. The most common types of refrigeration systems use the reverserankine vaporcompression refrigeration cycle, although absorption heat pumps are used in a minority of applications. The above figure shows the objectives of refrigerators and heat pumps. Ph diagram representation of a dry refrigeration cycle. This book has been written especially for use in programs where a full curriculum in refrigeration is offered. Which of the following is not a desirable property of a. 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. Request pdf simulation studies of refrigeration cycles. Its function is to provide a heat transfer surface through which heat can pass from the refrigerated space into the vaporizing refrigerant.
The compressor the condensing coil the metering device the evaporator 3. This involves absorption of heat at a lower temperature and rejection to higher temperature of the surroundings. Now in liquid form at high pressure, the refrigerant cools down as it flows into the coils inside the. 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. A chiller is a machine that removes heat from a liquid via a vaporcompression or absorption refrigeration cycle. It tells us how much refrigerant the evaporator absorbs, the refrigerant properties in the compressor, and how much refrigerant the condenser rejects.
Your customers may not need to go beyond this simple understanding of refrigeration. Refrigeration fundamentals heatcraft worldwide refrigeration. Cascade cycle is used where a very wide range of temperature between tl and th is. Heat pump and refrigeration cycles can be classified as vapor compression, vapor absorption, gas cycle, or stirling cycle types. Refrigeration onboard ships marine engineering study. It is lighter than air and has a sharp, pungent odor that serves as a warning of its presence. 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. The copper refrigerant tube a tube that connects these air conditioner parts well be discussing the ac cycle from splitcentral air conditioner units perspective. The transfer of heat by passing from a source to an example. There are primarily four types of compressors used in the airconditioning industry. Compressor types this period is devoted to the discussion of the different types of compressors. 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.
If an expander had been used the line from d to a would be a vertical line. Refrigeration cycle tutorial university of oklahoma. Pdf a conventional refrigeration cycle uses expansion device between the condenser and the evaporator which has losses. Jul 03, 2017 refrigeration deals with cooling of bodies or fluids to temperatures lower than those of surroundings. The four types of refrigeration systems you need to know. 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. A heat pump can be thought of as a heat engine which is operating in reverse. As a result, it can be used in different industries such as building, refrigeration. Zubair latif comsats institute of information technology, lahore 2. Th movement cooling by the removal of heat the movement of heat from a place where it is notot a ted to a. Multiple choice questions with answers on refrigeration. The challenge in refrigeration and air conditioning is to remove heat from a low temperature source and dump it at a higher temperature sink. There are various types of compressors used in the refrigeration and air conditioning machines, these are. Refrigeration deals with cooling of bodies or fluids to temperatures lower than those of surroundings.
Ppt refrigeration basics 101 powerpoint presentation. Multiple choice questions on refrigeration and air. The absorption refrigeration cycle is an alternative that absorbs the refrigerant in a liquid solution rather than evaporating it. Some basic refrigeration cycles are discussed here through different diagrams. The absorption refrigeration cycle is the subject of a separate clinic. 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. In other words, refrigeration is artificial humanmade cooling. This video is an animation of how the refrigeration cycle.
A free powerpoint ppt presentation displayed as a flash slide show on id. 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. All air conditioner units must have the five basic components to work. Refrigeration is a process that removes heat from a space, substance, or system to lower andor maintain its temperature below the ambient temperature. This cyclic process requires that work be input so that. An ejectorexpansion refrigeration cycle using nitrous oxide. Refrigeration and air conditioning objective questions and answers pdf. The refrigeration cycle explained in plain english. The compressor constricts the refrigerant vapor, raising its pressure, and pushes it into the coils on the outside of the refrigerator.
The refrigeration cycles can also be represented in a ph diagram. Refrigeration systems operate on a series of consecutive thermodynamic processes that form a cycle that returns the working substance to the same state. Principles of refrigeration pdf boilersinfo refrigeration cycle evaporator condenser receiver expansion device. A refrigeration carnot type cycle based on isothermal compression and two reversible expansions is proposed. It raises the pressure, temperature and enthalpy of the refrigerant by compressing the saturated gas, in an isentropic process, to a superheated. 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. Main parts of vapor compression refrigeration cycles. Compression refrigeration cycles in general take advantage of the idea that highly compressed fluids at one temperature will tend to. Just a short video explaining the basics of how most refrigeration systems operate. The main components there are four main components in a refrigeration system. 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. There are two basic types of absorption refrigeration cycle the lithium bromide.
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. Pdf analysis of refrigeration cycle performance with an ejector. The illustration above is a consumers understanding of refrigeration. The purpose of a refrigerator is the removal of heat, called the cooling load, from a lowtemperature medium.
Also covered in this chapter are the methods used for installing, maintaining, and repairing refrigeration equipment, including domestic refrigerators and freezers. A thermodynamic refrigeration cycle removes heat from a lowtemperature object refrigeration and rejects it at a higher temperature. Applications of refrigeration and air conditioning. Oct 19, 2019 the refrigeration plants on merchant vessels play a vital part in carrying refrigerated cargo and provisions for the crew on board. 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. The compressor does work on the refrigeration system consumes energy. Multiple choice questions with answers on refrigeration and. A refrigeration cycle, b vapour cycle, p1 pressure in the evaporator.
Refrigeration basics and lng university of oklahoma. 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. Industrial refrigeration and cooling invest northern ireland. In reefer ships, the temperature of the perishable or temperature sensitive cargo such as food, chemical, or liquefied gas, is controlled by the refrigeration. The resulting refrigerant vapor returns to the compressor inlet at point 1 to complete the thermodynamic cycle. 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 refrigeration plants on merchant vessels play a vital part in carrying refrigerated cargo and provisions for the crew on board. The trane air conditioning clinic series is one means of knowledge sharing. Although ideal, this cycle is close to a realistic one which could be designed with. The system uses two coolants, the first of which performs evaporative cooling and is then absorbed into the second. The copper refrigerant tube a tube that connects these air conditioner parts well be discussing the ac cycle from splitcentral air. An absorption refrigerator is a refrigerator that uses a heat source e. Refrigeration system an overview sciencedirect topics. Hvac and refrigeration system bureau of energy efficiency 73 figure 4.
The compressor compresses the refrigerant, which flows to the condenser, where it gets cooled. Selecting the right refrigerant there are several types of refrigerants such as cfcs, ammonia, hydrocarbons. Perform various cycle calculations for different types of refrigerants section. 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. This is a refrigeration cycle diagram of regular central air conditioner units. It has applications in both air conditioning and commercial and industrial refrigeration. Refrigeration is the process of heat removal from a low temperature sink and added to a high temperature reservoir to. Rev pages chapter 9 refrigerants, refrigeration cycles, and. Materials as printouts and additionally also as pdf files. While ammonia is a relatively toxic substance, it is not a cumulative poison. Wet refrigeration cycle the expander has been substituted by a throttling valve.
Two different pressures exist in the refrigeration cycle. This liquid can then be circulated through a heat exchanger to cool air or equipment as required. The two main types of hazardous refrigerants used in vessel. During the compression cycle, the refrigerant passes through four major. Basic refrigeration cycle nina sri maulani 121624023 tptu 2012 2.
Air conditioning clinic refrigeration cycle one of the. The operating principle of the refrigeration cycle was described mathematically by sadi carnot in 1824 as a heat engine. The vapor compression refrigeration cycle is a common method for transferring heat from a low temperature to a high temperature. The cannot coefficient of performance of cycle will be a 0. The traditional reciprocating compressor has been used in the industry for decades. It has applications in both air conditioning and commercial and. Thermodynamic heat pump cycles or refrigeration cycles are the conceptual and mathematical models for heat pumps and refrigerators. Hazards during the repair and maintenance of refrigeration.
Ppt refrigeration basics 101 powerpoint presentation free. As a result, it can be used in different industries such as building, refrigeration, mining, metallurgy, etc. So refrigeration cycle should be known to understand the refrigeration system. In a refrigeration cycle, the flow of refrigerant is controlled by a compressor b condense. Multiple choice questions with answers on refrigeration and airconditioning set 07 practice test. May 15, 2018 the most widely used refrigeration cycle method is mechanical compression. Cops for the three types of co2 refrigeration cycles correspond to a. Different types of main components such as compressors, evaporators and condensers, as well. Refrigeration cycle is the basis of all refrigeration systems. 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. Two principle types of refrigeration plants found in industrial use are.
Energy in the form of heat is removed from a lowtemperature reservoir and transferred to a hightemperature reservoir. 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. Oct 12, 2012 this video is an animation of how the refrigeration cycle works, with each components function. 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 most widely used refrigeration cycle method is mechanical compression. The refrigeration cycle tells us if there is air in the central air conditioner units, what to repair after troubleshooting. Gas refrigeration cycles include the reversed brayton cycle and the hampsonlinde cycle.
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