The specific gravity of any substance is the ratio of weight of a given volume of the substance to the weight of the same volume of a given substance. The term tons of refrigeration is also used to refer to the cooling load on a room or building. A comprehensive applicationsoriented treatment of the mechanical refrigeration cycle and associated equipment. May 21, 2007 the term tons of refrigeration is also used to refer to the cooling load on a room or building. Their worksites may be very hot or cold because the heating and cooling systems they must repair may not be working properly and because. This text provides a detailed, applicationsoriented treatment of the mechanical refrigeration cycle, associated equipment, component design, and system operation. Office of education division of visual aids principles of refrigeration ava12779vnb1 the principles of refrigeration explained. A refrigeration system is a heat pump, just like a heater is a heat pump. Publication date 1961 topics refrigeration and refrigerating machinery. Feb 15, 2009 the book is principles of refrigeration by roy dossat. The refrigeration system requires some means of connecting the basic major components evaporator, compressor, condenser, and metering device just as roads connect communities. Superheating refrigeration cycle of twostage compound. The danfoss product range for the refrigeration and air.
Well designed packing house facilities that conform to the principles of good manufacturing. This is essential to be successful in the hvac industry. Refrigeration is the branch of science that deals with the process of reducing and maintaining the temperature of a space or material below the temperature of the surroundings. Dossat principles of refrigeration john wiley 1961 acrobat 7 pdf 35. An overview of the fundamental principles of physics and thermodynamicsincludes an introduction to psychometrics. Refrigeration fundamentals heatcraft worldwide refrigeration. Principles of refrigeration is considered an essential resource for engineers world wide, but few people know anything of the author himself.
It is intended to cover only the fundamentals of refrigeration theory and practice. Uploaded by associateangeladugas on september 6, 2012. It teaches students how processes can be broken down into fundamental principles so that they can develop analytical skills, correctly analyze and troubleshoot systems, and embark. Refrigeration basic principle named after two scientists, james prescott joule and william thompson. At a lower temperature, molecular motion slows down and the growth of bacteria that causes food spoilage also retards. Dossat remained a member of this new, combined society. Vcr uses mechanical energy as the driving force for refrigeration, while var uses thermal energy as the driving force for refrigeration. A tone of refrigeration is expressed in designed as the rate of heat removed from the surroundings equivalent to the heat required for melting one tone of ice in one day 20140304 3 faculty of pharmacy, omer almukhtar university, tobruk, libya. In order to properly identify and control hazards in an ammonia refrigeration system, it is necessary to understand how a refrigeration system operates. When 1 pound of ice melts, it absorbs 144 btu, as latent energy. Practically speaking, substance 1 is a refrigerant, with ammonia being the most commonly used in industrial refrigeration systems. Price new from used from hardcover, international edition, january 28, 1981 please retry.
Dossat presented the fundamentals of refrigeration theory, components and systems to students who were preparing to enter an occupation rich with opportunities. Gosney, 1982, cambridge university press edition, in english. The science behind refrigeration berg chilling systems inc. The suction line connects the evaporator or cooling coil to. The basic principles are those of thermodynamics, and these principles as. Refrigeration the process of cooling or maintaining temperature in a space or object by removing heat pressure a force per unit area applied directly to a surface temperature the measurement of the intensity of heat energy in an object sensible heat heat energy that causes a change in temperature. Refrigeration systems and applications, second edition. 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.
Good practice in the design, management and operation of a fresh. Paul reed the elements everything in, on, or around the earth, sun, moon and stars, including our bodies themselves, is made up of one or more of 92 basic elements. One ton of refrigeration is the amount of latent heat absorbed when one ton of ice at 32f melts to water at 32f during 24 hours. Metering device we will now take a closer look at the individual components of the system. Heat capacity is the change in heat content or enthalpy for one pound of material for one degree of temperature change. Principles of refrigeration 5th edition by roy j dossat. Tubing or lines make the system complete so that the refrigerant will not leak out into the atmosphere. Open library is an initiative of the internet archive, a 501c3 nonprofit, building a digital library of internet sites and other cultural artifacts in digital form.
Pdf dossatprinciples of refrigeration paola ramirez. Density and specific gravity of some common substances. 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. Horan and a great selection of related books, art and collectibles available now at. Refrigeration basic principle refrigeration evaporators. Sep 28, 2015 capacity of refrigeration is expressed in tone. Principles of refrigeration 1982 edition open library. This procedure is called a throttling process or joulethomson. Principles of refrigeration, by r j dossat and t j horan, 2001. Dossats text in high esteem is illustrated by the following two figures which are simply scans of pages in two different books. In frostfree models, a separate thermostat with a timer controls the defrosting cycle. Principles of refrigeration roy j dossat, phi,free ebook. Pdf refrigeration and air conditioning third edition johana c.
Jul 19, 2001 principles of refrigeration has been one of the foundation textbooks in the refrigeration field since roy dossat wrote the first edition in 1961. A refrigerator thermostat has only one function controlling the refrigerators cooling system by turning it on or off to ensure that the temperature inside the fridge stays in the correct range of 33 to 40 degrees fahrenheit. Without understanding the basic principles, one is likely to be confused, slow to respond, or even incorrect when identifying unsafe conditions. Hvacr technicians work mostly in homes, schools, hospitals, office buildings, or factories. Refrigeration is a process wherein the pressure of substance 1 is manipulated in order to control the temperature of substance 1 for the purpose of lowering the temperature of substance 2. Guide for air conditioning, refrigeration, and heating. Document resume ed 251 645 ce 040 232 author henderson, william edward, jr. 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. It teaches students how processes can be broken down into fundamental principles so that they can develop analytical skills, correctly analyze and troubleshoot systems, and embark upon successful careers as technicians. Mar 19, 2020 a refrigerator thermostat has only one function controlling the refrigerators cooling system by turning it on or off to ensure that the temperature inside the fridge stays in the correct range of 33 to 40 degrees fahrenheit.
Welcome to the manual for refrigeration servicing technicians. Internet archive bookreader principles of refrigeration. The test rig is designed for the study of vapour compression refrigeration cycle. Thermodynamics and design principles of refrigeration systems.
For both students and professionals, this book presents the science behind the operation of refrigeration systems as a method for building solid analytical skills, which will set the studenttechnician apart when it comes to understanding and troubleshooting. Principles of refrigeration is a classic book done by roy j dossat published by phi is one of the primary reference book for the course be10102 introduction to mechanical engineering sciences for kerala technologicaltechnical university ktu. Title artculated, performancebased instruction objectives. One ton of refrigeration equals 12,000 btu per hour btuh. It is the principal element in coal, wood, paper, cloth, natural gas, gasoline. Where solids or liquids are concerned water is used as a basis for specific gravity calculations, and air or hydrogen is used as a standard for gases. Heating, air conditioning, and refrigeration mechanics and installers work on heating, ventilation, cooling, and refrigeration systems work environment. On completion of this course, students should be able to 1. Principles of refrigeration has been one of the foundation textbooks in the refrigeration field since roy dossat wrote the first edition in 1961.
Nature of heat heat is a form of energy contained to some extent in every substance on earth. Heating, air conditioning, and refrigeration mechanics and. Jul 19, 2001 principles of refrigeration provides comprehensive coverage of refrigeration theory, components, and systems analysis and design. 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. Refrigeration heat transfer devices such as air cooled condensers and evaporators are often made out of copper pipes with aluminum fins and further enhanced with fans to force air through the fins.
Pdf performance analysis and development of a refrigeration. The numerical figure is the same with either set of units. Principles of refrigeration by dossat and a great selection of related books, art and collectibles available now at. If the very cold material is slightly warmed by adding a little heat, the molecules begin to move somewhat, and the motion of the molecules becomes greater the warmer the material becomes. Refrigeration fundamentals 2175 west park place blvd. Dossat joined asre in 1955, a few years before its merger with ashve formed ashrae. Manual for refrigeration servicing introduction technicians. Dossat is the author of principles of refrigeration 4. The set up demonstrates the basic principal of a refrigeration cycle. This course will provide the sales person, technician or engineer with a strong foundation and a thorough understanding of the refrigeration circuit, the heart of the hvac system. Principles of refrigeration provides comprehensive coverage of refrigeration theory, components, and systems analysis and design. It started with his desire to know more after doing refrigerator repair work with two brothers who worked out of their garage in the mid 1940s. Principles of refrigeration, by r j dossat and t j horan, reading architectural drawings pdf 2001. This cycle seems to combine with many actions, particularly catalytic destructive.
Pdf in this study, a refrigeration cycle was simulated with different refrigerants in a petrochemical plant in iran. In the past, this was done by collecting ice in the winter and using its specific heat to cool as the ice melted. The ebook pdf for that is not easily available also however after a tremendous search we fou. This process can be as simple as placing a dish of strawberries in a snowbank or as. Principles of refrigeration 5th edition by dossat, roy j. The resulting principles of refrigeration, first published in 1961, is currently in its 5th edition and still going strong.
For both students and professionals, this book presents the science behind the operation of refrigeration systems as a method for building solid analytical skills, which will set the studenttechnician apart when it comes to understanding and troubleshooting system. Refrigeration vcr and vapour absorption refrigeration var. Provides students with material that is essential to an understanding of mechanical refrigeration. This manual is designed to fill a need which exists for a concise, elementary text to aid servicemen, salesman, students, and others interested in refrigeration. Dossats career is both interesting and inspirational. 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. This book provides a detailed, applicationsoriented tre.