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. Different types of main components such as compressors, evaporators and condensers, as well. There are primarily four types of compressors used in the airconditioning industry. Th movement cooling by the removal of heat the movement of heat from a place where it is notot a ted to a.
If an expander had been used the line from d to a would be a vertical line. 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. A refrigeration carnot type cycle based on isothermal compression and two reversible expansions is proposed. Pdf analysis of refrigeration cycle performance with an ejector. The main components there are four main components in a refrigeration system.
Refrigeration cycle it is a well known fact that heat flows in the direction of decreasing temperature, i. Refrigeration deals with cooling of bodies or fluids to temperatures lower than those of surroundings. The illustration above is a consumers understanding of refrigeration. In a refrigeration cycle, the flow of refrigerant is controlled by a compressor b condense. 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. In reefer ships, the temperature of the perishable or temperature sensitive cargo such as food, chemical, or liquefied gas, is controlled by the refrigeration. Ppt refrigeration basics 101 powerpoint presentation. Refrigeration is a process that removes heat from a space, substance, or system to lower andor maintain its temperature below the ambient temperature. Your customers may not need to go beyond this simple understanding of refrigeration. However, they may expect you to have a much greater indepth understanding of refrigeration to help them solve their cooling needs. The traditional reciprocating compressor has been used in the industry for decades. Cascade cycle is used where a very wide range of temperature between tl and th is.
Now in liquid form at high pressure, the refrigerant cools down as it flows into the coils inside the. 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. This is a refrigeration cycle diagram of regular central air conditioner units. Study 72 terms basic refrigeration questions flashcards. 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. 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 free powerpoint ppt presentation displayed as a flash slide show on id. 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. The absorption refrigeration cycle is an alternative that absorbs the refrigerant in a liquid solution rather than evaporating it.
The refrigeration cycles can also be represented in a ph diagram. Selecting the right refrigerant there are several types of refrigerants such as cfcs, ammonia, hydrocarbons. During the compression cycle, the refrigerant passes through four major. An absorption refrigerator is a refrigerator that uses a heat source e. The refrigeration cycle tells us if there is air in the central air conditioner units, what to repair after troubleshooting. Some basic refrigeration cycles are discussed here through different diagrams. Pdf a conventional refrigeration cycle uses expansion device between the condenser and the evaporator which has losses. Materials as printouts and additionally also as pdf files.
Principles of refrigeration pdf boilersinfo refrigeration cycle evaporator condenser receiver expansion device. Its function is to provide a heat transfer surface through which heat can pass from the refrigerated space into the vaporizing refrigerant. Multiple choice questions with answers on refrigeration and. Gas refrigeration cycles include the reversed brayton cycle and the hampsonlinde cycle. Refrigeration cycles the vapor compression refrigeration cycle is a common method for transferring heat from a low temperature to a high temperature. Although ideal, this cycle is close to a realistic one which could be designed with.
All air conditioner units must have the five basic components to work. A thermodynamic refrigeration cycle removes heat from a lowtemperature object refrigeration and rejects it at a higher temperature. There are various types of compressors used in the refrigeration and air conditioning machines, these are. The compressors are one of the most important parts of the refrigeration cycle. May 15, 2018 the most widely used refrigeration cycle method is mechanical compression. Applications of refrigeration and air conditioning. Hazards during the repair and maintenance of refrigeration. Oct 12, 2012 this video is an animation of how the refrigeration cycle works, with each components function. The copper refrigerant tube a tube that connects these air conditioner parts well be discussing the ac cycle from splitcentral air. Refrigeration system an overview sciencedirect topics. Just a short video explaining the basics of how most refrigeration systems operate. So refrigeration cycle should be known to understand the refrigeration system.
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. This book has been written especially for use in programs where a full curriculum in refrigeration is offered. When the hot gas in the coils meets the cooler air temperature of the kitchen, it becomes a liquid. While ammonia is a relatively toxic substance, it is not a cumulative poison. 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. Air conditioning clinic refrigeration cycle one of the. Wet refrigeration cycle the expander has been substituted by a throttling valve. This cyclic process requires that work be input so that. The purpose of a refrigerator is the removal of heat, called the cooling load, from a lowtemperature medium. Oct 19, 2019 the refrigeration plants on merchant vessels play a vital part in carrying refrigerated cargo and provisions for the crew on board. Zubair latif comsats institute of information technology, lahore 2.
The resulting refrigerant vapor returns to the compressor inlet at point 1 to complete the thermodynamic cycle. The cannot coefficient of performance of cycle will be a 0. The refrigeration plants on merchant vessels play a vital part in carrying refrigerated cargo and provisions for the crew on board. Refrigeration systems operate on a series of consecutive thermodynamic processes that form a cycle that returns the working substance to the same state. Two principle types of refrigeration plants found in industrial use are. Request pdf simulation studies of refrigeration cycles. A refrigeration cycle, b vapour cycle, p1 pressure in the evaporator. The challenge in refrigeration and air conditioning is to remove heat from a low temperature source and dump it at a higher temperature sink. Jul 03, 2017 refrigeration deals with cooling of bodies or fluids to temperatures lower than those of surroundings.
Vapor compression refrigeration system basic, working. 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. 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. Multiple choice questions with answers on refrigeration. Compressor types this period is devoted to the discussion of the different types of compressors. Refrigeration onboard ships marine engineering study.
Heat pump and refrigeration cycles can be classified as vapor compression, vapor absorption, gas cycle, or stirling cycle types. It has applications in both air conditioning and commercial and. 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. 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. 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. It raises the pressure, temperature and enthalpy of the refrigerant by compressing the saturated gas, in an isentropic process, to a superheated. The trane air conditioning clinic series is one means of knowledge sharing. A heat pump can be thought of as a heat engine which is operating in reverse. Basic refrigeration cycle nina sri maulani 121624023 tptu 2012 2. Industrial refrigeration and cooling invest northern ireland. The transfer of heat by passing from a source to an example. The two main types of hazardous refrigerants used in vessel.
Perform various cycle calculations for different types of refrigerants section. Two different pressures exist in the refrigeration cycle. 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. The refrigeration cycle explained in plain english. In other words, refrigeration is artificial humanmade cooling.
The absorption refrigeration cycle is the subject of a separate clinic. Multiple choice questions with answers on refrigeration and airconditioning set 07 practice test. Refrigeration is the process of heat removal from a low temperature sink and added to a high temperature reservoir to. Refrigeration cycle tutorial university of oklahoma. Multiple choice questions on refrigeration and air. The operating principle of the refrigeration cycle was described mathematically by sadi carnot in 1824 as a heat engine. Rev pages chapter 9 refrigerants, refrigeration cycles, and. The compressor does work on the refrigeration system consumes energy. A chiller is a machine that removes heat from a liquid via a vaporcompression or absorption refrigeration cycle. The four types of refrigeration systems you need to know. Ph diagram representation of a dry refrigeration cycle. The most common types of refrigeration systems use the reverserankine vaporcompression refrigeration cycle, although absorption heat pumps are used in a minority of applications.
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. Which of the following is not a desirable property of a. 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. The system uses two coolants, the first of which performs evaporative cooling and is then absorbed into the second. This involves absorption of heat at a lower temperature and rejection to higher temperature of the surroundings. As a result, it can be used in different industries such as building, refrigeration, mining, metallurgy, etc. There are two basic types of absorption refrigeration cycle the lithium bromide. It tells us how much refrigerant the evaporator absorbs, the refrigerant properties in the compressor, and how much refrigerant the condenser rejects. Refrigeration and air conditioning objective questions and answers pdf. Thermodynamic heat pump cycles or refrigeration cycles are the conceptual and mathematical models for heat pumps and refrigerators. The compressor constricts the refrigerant vapor, raising its pressure, and pushes it into the coils on the outside of the refrigerator. Ppt refrigeration basics 101 powerpoint presentation free. This video is an animation of how the refrigeration cycle works, with each components function.
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. Refrigeration fundamentals heatcraft worldwide refrigeration. 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. The copper refrigerant tube a tube that connects these air conditioner parts well be discussing the ac cycle from splitcentral air conditioner units perspective. As a result, it can be used in different industries such as building, refrigeration. 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 vapor compression refrigeration cycle is a common method for transferring heat from a low temperature to a high temperature. An ejectorexpansion refrigeration cycle using nitrous oxide.
Bahrami ensc 461 s 11 refrigeration cycle 6 cascade refrigeration cycle systems that have 2 or more refrigeration cycles operating in series. 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. This video is an animation of how the refrigeration cycle. Refrigeration cycle is the basis of all refrigeration systems. Also covered in this chapter are the methods used for installing, maintaining, and repairing refrigeration equipment, including domestic refrigerators and freezers. It is lighter than air and has a sharp, pungent odor that serves as a warning of its presence. It has applications in both air conditioning and commercial and industrial refrigeration. Energy in the form of heat is removed from a lowtemperature reservoir and transferred to a hightemperature reservoir. Refrigeration basics and lng university of oklahoma. The most widely used refrigeration cycle method is mechanical compression. Cops for the three types of co2 refrigeration cycles correspond to a. The compressor compresses the refrigerant, which flows to the condenser, where it gets cooled. Hvac and refrigeration system bureau of energy efficiency 73 figure 4.
364 1325 828 1062 598 191 205 1261 798 1593 930 299 869 594 835 72 543 725 988 342 1176 808 325 283 2 49 1014 649 1404 797 897 696 934 1269 316 171 226 1494 51 1038 42 236 189 180 687 26 1005