Heat capacity is the change in heat content or enthalpy for one pound of material for one degree of temperature change. Refrigeration and air conditioning technology gunt hamburg. Refrigeration and air conditioning systems onboard ships vapour. Dossat principles of refrigeration john wiley 1961 acrobat 7 pdf 35. It covers residential equipment only, including window units, automobile units, and refrigerators. This book has been written especially for use in programs where a full curriculum in refrigeration is offered. Care and maintenance of tool, instruments and equipments.
The principal characteristics of each component are as follows. Describe the working principle of reciprocating compressors section 18. Hvac is an acronym for heating, ventilation, and air conditioning. Manual for refrigeration servicing introduction technicians. Sep 28, 2015 principle of refrigeration the refrigeration cycle is also known as vapour compression cycle. Example use the refrigerant4a tables 1 1 1 1 1 238. Pdf design of refrigeration system using refrigerant r4a for. Refrigerator working principle the working principle of a refrigerator and refrigeration, in general is very simple. As pressure decreases, the changeofstate temperature also decreases. Heat and refrigeration principles learning objective. When 1 pound of ice melts, it absorbs 144 btu, as latent energy. Downing technical consult, dupont company introduction refrigeration is the process of taking heat from someplace where it isnt wanted and disposing of it somewhere else.
When the ion exchange membrane electrode assembly mea is charged with a dc voltage, the gas refrigerant molecules on one side of the membrane are split into ions and electrons. For the first time, the book has been prepared with both the homeowner. A refrigeration system is a heat pump, just like a heater is a heat pump. If both refrigeration effect and work done by the compressor or the input power are taken in the same units tr or kcalhr or kw or btuhr, the ratio is. Introduction to trade, general safety precautions and first aids, history of refrigeration and air conditioning. It is based on the second law of thermodynamics that the heat can made. So, when installing a new system or working on an existing system, the actions taken should ideally lead to the system operating with. Screw chiller working principle pdf these principles are increasingly applied. The vapour used is cycled between liquid and gaseous phases. Basic principles most of us have some ideas concerning the purpose of refrigeration and what refrigeration does.
The pressuretemperature relationship is an important principle for refrigeration. The articles referenced here will give you a full and complete. When compiling the material for the booklet a deliberate. Title artculated, performancebased instruction objectives. Refrigeration basic principle refrigeration evaporators.
The system has a cool side and a warm side, and by pumping a fluid through the cool side it collects heat, and then pumps it to the warm side, where it expands, and gives up. Nature of heat heat is a form of energy contained to some extent in every substance on earth. Refrigeration basic principle named after two scientists, james prescott joule and william thompson. Hovercraft projectseminar report pdf and ppt download for. Guide for air conditioning, refrigeration, and heating. This principle is applied in the refrigeration system. There is no need to change the program or recompile, making it simple to. Technical data aquaforce 30xwp 30xwhp watercooled screw chiller. Air conditioning and refrigeration rex miller professor emeritus state university college at buffalo buffalo, new york mark r. The vane splits the space between the cylinder and the.
On completion of this course, students should be able to 1. The process where a gas or liquid change its temperature when it is forced through an expansion valve or capillary tube in an insulated system where no ambient heat transfer. The danfoss product range for the refrigeration and air. In this cycle, a circulating refrigerant enters a compressor as lowpressure vapor at or. Based reading and writing pdf files in java on the working principle, refrigeration systems can be. The standard vapor compression refrigeration system is a condenser, evaporator, throttling valve, and a compressor. Working principle, types and comparison with vapor compression system, saving potential. Office of education division of visual aids principles of refrigeration ava12779vnb1 the principles of refrigeration explained. Basics of air conditioning most people dont realize how their central air conditioner actually works.
Tubing or lines make the system complete so that the refrigerant will not leak out into the atmosphere. The refrigeration system requires some means of connecting the basic major components evaporator, compressor, condenser, and metering device just as roads connect communities. In order to have a better understanding if these systems, you need to know some of the principles behind hvac design. The principle of working of a hovercraft is to lift the craft by a cushion of air to propel it using propellers. But your air conditioner actually removes warm air and recirculates it as cool air. Miller professor, industrial technology the university of texas at tyler tyler, texas mcgrawhill new york chicago san francisco lisbon london madrid mexico city milan new delhi san juan seoul singapore sydney toronto. The information included on refrigeration components is general in nature and is intended only to give a brief. Mechanical refrigeration works by changing the the majority of heat is removed from the the majority of the works by removedchanging the absorbed heat is state of the refrigerant. The book is to maintaining and repairing all types of hvac cooling and refrigeration units. If, however, the applied pressure is raised to a higher value, then additional heat is required to vaporize the liquid. His basic principle that of compressing a gas, cooling it by sending it through radiating coils, and then expanding it to lower the temperature further is the one most often used in refrigerators today.
The idea of supporting the vehicle on a cushion of air developed from the idea to increase the speed of boat by feeding air beneath them. Definitions solenoid valves are found in many applications and are commonly used in refrigeration and air conditioning systems. 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 both a building system designed to keep the environment comfortable for building occupants and the industry that supports these systems. Solenoid valves play an important role within refrigeration and air conditioning systems, controlling the flow of refrigerants.
Refrigeration and air conditioning systems onboard ships vapour compression systems moving heat from a lower temperature to higher temperature requires work to be done, according to second law of thermodynamics and this work can be done in many ways in different systems. When you pass a lowtemperature liquid close to objects that you want to cool, heat from those objects is transferred to the liquid, which. A vapor compression cycle is used in most freezers. For 30 years, topics such as air refrigeration cycles and systems, vapour. The refrigerant leaves the evaporator at 20oc and has a condenser pressure of 0. However, they may expect you to have a much greater indepth. Refrigeration can be analysed just at a conceptual system level as done here what purpose it must accomplish, how it can be done in principle, how it can be done in practice, or it can be analysed in more detail to include also the study of the components used in refrigeration equipment. The numerical figure is the same with either set of units. Working principle of electrochemical compression of nh 3 and co 2 fig. This process can be as simple as placing a dish of strawberries in a snowbank or as. Though their base function turning the refrigerant flow on and off is quite simple, this function is key to ensuring system performance. Feng, epa refrigerator analysis program user manual, version 1. The working principle of freezer snowballmachinery.
Refrigeration cycle in a vapor compression refrigeration system a gas refrigerant is alternatively compressed and expanded and goes from the liquid to the vapor state. This is the principle behind vapour compression systems. As a refrigerant, it is a manufactured product that conforms to strict purity specifications. Understand the basic principles of refrigeration and air conditioning, 2. Special university course for future engineers lecture notes. In this lesson, the basic working principle of absorption systems, the maximum cop of ideal absorption refrigeration systems, basics of properties of mixtures and simple absorption refrigeration systems will be discussed. Refrigerator working principle pdf plant but who wish to extend their knowledge on the basic principles of. Refrigeration and airconditioning is the subject which deals with the techniques to control the environments of the living and nonliving subjects and thus provide them comforts to enable them to perform better and have longer lives. Pdf textbook of refrigeration and air conditioning by r. Chillers are a key component of air conditioning systems for large buildings. The illustration above is a consumers understanding of refrigeration. Solenoid valves and their importance in refrigeration systems. This principle explains why you cant make good tea up a high mountain the water boils at only about 90c because of the lower pressure. The siunit for temperature kelvin k is an abso lute temperature because its reference point 0 k is the lowest temperature that it in theory would be able to.
Guide to hvac design, theory of operation, and primary. So, when installing a new system or working on an existing system, the actions taken. Explain the basics of heat theory and the basic principles of refrigeration. The system pressures are much higher than in conventional systems, and all. Refrigerant4a is the working fluid in an ideal compression refrigeration cycle. Discuss the performance aspects of ideal reciprocating compressors with and without clearance section 18. It is based on the second law of thermodynamics that the heat can made to flow from cold body to a hot body with the help of external source. The cycle operates at two pressures high and low, to produces a continuous cooling effect. Based on the working principle, refrigeration systems can be classified as vapour compression systems, vapour absorption. Principles of refrigeration, by r j dossat and t j horan, 2001. Welcome to the manual for refrigeration servicing technicians. Refrigeration system components emerson climate technologies. Air conditioning and refrigeration repair by roger a.
The suction line connects the evaporator or cooling coil to. Principle of refrigeration the refrigeration cycle is also known as vapour compression cycle. Refrigeration fundamentals 2175 west park place blvd. They think that an air conditioner functions by pumping cool air into their home. Download textbook of refrigeration and air conditioning by r. Materials as printouts and additionally also as pdf files. 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. Mar 22, 2017 a refrigeration system is a heat pump, just like a heater is a heat pump. In this cycle, a circulating refrigerant enters a compressor as lowpressure vapor at or slightly above the temperature of the freezer interior. Manual for refrigeration servicing technicians unep dtie. Basics of air conditioning bayonet plumbing, heating, and ac.
This procedure is called a throttling process or joulethomson. Find cop r and cop r, carnot for the same t max and t min, and the tons of refrigeration. Refrigeration and air conditioning systems onboard ships. Your customers may not need to go beyond this simple understanding of refrigeration. Nov 15, 2015 refrigerator working principle the working principle of a refrigerator and refrigeration, in general is very simple. Small capacity modular units of direct expansion type similar to domestic refrigerators. Transcritical refrigeration systems with carbon dioxide co.
Further understanding and observation of the working principle of refrigeration and parameters affecting the performance of the refrigeration system is also indispensable. Function, working, use, specifications of refrigeration tools, instruments and equipment. When a liquid evaporates it causes the surrounding area to cool. The compressors used in domestic refrigerators are. Article transcritical refrigeration systems with carbon dioxide co 2 danfoss as ra marketingmwa, july 2008 dkrci. The science behind refrigeration berg chilling systems inc. Vapor compression refrigeration cycle, refrigerants, coefficient of performance, capacity, factors affecting refrigeration and air conditioning system performance and savings opportunities. Refrigeration fundamentals heatcraft worldwide refrigeration. Pdf household refrigerators and freezers researchgate. May 21, 2007 the pressuretemperature relationship is an important principle for refrigeration. Funnel flaps working, construction and regulations funnel flaps in a ship refers to the movable closures or windows present in the aft. A solenoid valveis an electromechanical valve frequently used to control the flow of liquid or gas. Chapter 18 refrigeration plant and mine air conditioning systems malcolm j. In the past, this was done by collecting ice in the winter and using its specific heat to cool as the ice melted.
The basic working principle of a freezer is evaporation. The different types of cooling compressors rotaryvane compressor a rotaryvane compressor is also known as a rotary piston compressor because the function of the vane is similar to that of a piston shown in figure 3. Understanding how solenoid valves work increases the likelihood that. Khurmi a textbook of refrigeration and air conditioning is an aptly written textbooks for the students of mechanical engineering while also a mustread for anyone with an interest in the subject. Refrigeration manual when people should go to the books stores, search initiation by shop, shelf by shelf, it is truly problematic. Document resume ed 251 645 ce 040 232 author henderson, william edward, jr. Based on the working principle, refrigeration systems can be classified as vapour compression systems, vapour absorption systems, gas cycle systems etc. Refrigeration is the process of removing heat from an area or a substance and is usually done by an artificial means of lowering the temperature, such as the use of ice or mechanical refrigeration.