top of page

The Ricketts Foundat Group

Public·23 members
Cody Singh
Cody Singh

Principles of Refrigeration by Roy J. Dossat: The Best Book on Refrigeration for Students and Professionals


Principles of Refrigeration by Roy J. Dossat: A Comprehensive Guide




If you are interested in learning about the theory and practice of refrigeration, you may want to check out the book Principles of Refrigeration by Roy J. Dossat. This book is considered one of the classic texts on refrigeration, covering the fundamental concepts, systems, components, design, control, and operation of refrigeration processes. In this article, we will give you an overview of the book's contents, features, and benefits, and show you how you can download a PDF version of it for free.




principles of refrigeration roy j dossat pdf download



Introduction




What is refrigeration and why is it important?




Refrigeration is the process of removing heat from a substance or a space to lower its temperature below that of its surroundings. Refrigeration is used for various purposes, such as preserving food, cooling buildings, producing ice, liquefying gases, freezing biological materials, and enhancing industrial processes. Refrigeration is essential for modern life, as it improves health, comfort, safety, and productivity.


Who is Roy J. Dossat and what is his contribution to refrigeration?




Roy J. Dossat was a professor of mechanical engineering at Purdue University and a renowned expert on refrigeration. He authored several books and papers on refrigeration topics, such as thermodynamics, heat transfer, psychrometrics, compressors, evaporators, condensers, expansion devices, piping, controls, load calculations, system design, operation, and maintenance. He also served as a consultant for various refrigeration companies and organizations. He was awarded the F. Paul Anderson Medal by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) for his outstanding contributions to the field.


What are the main features and benefits of his book?




His book Principles of Refrigeration was first published in 1961 and has been revised several times since then. It is widely used as a textbook for undergraduate and graduate courses on refrigeration engineering, as well as a reference book for professionals and practitioners. The book has the following features and benefits:



  • It covers the basic principles of refrigeration as well as the practical aspects of refrigeration systems and components.



  • It explains the concepts in a clear and concise manner, using diagrams, tables, charts, examples, problems, and solutions.



  • It provides a comprehensive and up-to-date treatment of refrigeration topics, such as refrigerants, refrigeration cycles, refrigeration systems, refrigeration components, refrigeration load calculations, refrigeration system design, refrigeration control, and refrigeration operation and maintenance.



  • It reflects the latest standards, codes, and regulations related to refrigeration, such as ASHRAE, ANSI, UL, and EPA.



  • It is suitable for both beginners and advanced learners, as it covers the fundamentals as well as the advanced topics of refrigeration.



Chapter 1: Basic Concepts of Refrigeration




The refrigeration cycle and its components




The refrigeration cycle is the process of transferring heat from a low-temperature region to a high-temperature region using a working fluid called a refrigerant. The refrigeration cycle consists of four main components: a compressor, a condenser, an expansion device, and an evaporator. The compressor raises the pressure and temperature of the refrigerant vapor. The condenser rejects the heat from the refrigerant vapor to a cooling medium and converts it to a liquid. The expansion device lowers the pressure and temperature of the refrigerant liquid. The evaporator absorbs the heat from a cooling medium and converts the refrigerant liquid to a vapor. The cycle repeats itself until the desired cooling effect is achieved.


The properties of refrigerants and their classification




A refrigerant is a substance that can undergo phase changes between liquid and vapor at low temperatures and pressures. A refrigerant should have desirable properties, such as high latent heat of vaporization, low specific volume, low viscosity, high thermal conductivity, high critical temperature and pressure, low freezing point, low toxicity, low flammability, low environmental impact, and low cost. Refrigerants are classified into different groups based on their chemical composition, such as halocarbons (CFCs, HCFCs, HFCs), hydrocarbons (propane, butane), inorganic compounds (ammonia, carbon dioxide), and natural substances (water, air).


The pressure-enthalpy diagram and its applications




A pressure-enthalpy diagram is a graphical representation of the thermodynamic properties of a refrigerant at different pressures and enthalpies. Enthalpy is a measure of the total energy of a substance. A pressure-enthalpy diagram shows the phase boundaries between liquid and vapor states, the saturation curves for constant temperature and constant pressure, the critical point where liquid and vapor coexist at the highest temperature and pressure, and the ideal and actual refrigeration cycles. A pressure-enthalpy diagram can be used to analyze the performance of a refrigeration system, such as the coefficient of performance (COP), the heat transfer rates, the power consumption, the mass flow rate, and the quality of the refrigerant.


Chapter 2: Refrigeration Systems and Components




The types of refrigeration systems and their advantages and disadvantages




Refrigeration systems can be classified into different types based on their working principle, such as vapor compression systems, vapor absorption systems, gas cycle systems, steam jet systems, thermoelectric systems, magnetic systems, etc. Each type of system has its own advantages and disadvantages in terms of efficiency, reliability, complexity, cost, environmental impact, etc. For example:



  • Vapor compression systems are the most common type of refrigeration systems. They use mechanical work to compress and circulate a refrigerant through a closed loop. They have high COPs, low operating costs, wide range of applications, but they also require electricity, have moving parts that can wear out, and use synthetic refrigerants that can harm the ozone layer or contribute to global warming.



  • Vapor absorption systems use thermal energy to drive a solution of a refrigerant and an absorbent through a closed loop. They have low COPs, high initial costs, limited applications, but they also use natural or low-GWP refrigerants, have no moving parts that can break down, and can utilize waste heat or solar energy as heat sources.



The components of refrigeration systems and their functions




Refrigeration systems consist of various components that perform specific functions in the cycle. Some of the common components are:



  • A compressor is a device that increases the pressure and temperature of the refrigerant vapor by reducing its volume. It provides the driving force for the cycle.



  • A condenser is a heat exchanger that transfers heat from the high-pressure refrigerant vapor to a lower-temperature cooling medium (such as air or water) and converts it to a liquid.



between the high-pressure and low-pressure sides of the system.


  • An evaporator is a heat exchanger that transfers heat from a lower-temperature cooling medium (such as air or water) to the low-pressure refrigerant liquid and converts it to a vapor.



  • A refrigerant is a fluid that circulates through the system and undergoes phase changes between liquid and vapor. It absorbs heat from the cooling medium in the evaporator and rejects heat to the cooling medium in the condenser.



  • An absorbent is a fluid that dissolves the refrigerant in a vapor absorption system. It increases the concentration of the refrigerant in the solution and lowers its vapor pressure.



  • A generator is a device that supplies heat to the solution of refrigerant and absorbent in a vapor absorption system. It separates the refrigerant from the absorbent by boiling it off.



  • A condenser-absorber is a device that combines the functions of a condenser and an absorber in a vapor absorption system. It cools and liquefies the refrigerant vapor from the generator and absorbs it into the absorbent solution.



  • An evaporator-generator is a device that combines the functions of an evaporator and a generator in a vapor absorption system. It evaporates the refrigerant liquid from the condenser-absorber and generates refrigerant vapor by heating it with a secondary fluid.



Chapter 3: Refrigeration Load Calculations and System Design




The factors affecting refrigeration load and how to estimate it




The refrigeration load is the amount of heat that must be removed from a space or a substance to maintain its desired temperature. The refrigeration load depends on various factors, such as:



  • The size, shape, orientation, insulation, and infiltration of the space or the substance.



  • The temperature difference between the inside and outside of the space or the substance.



  • The heat sources and sinks inside or outside the space or the substance, such as people, lights, appliances, windows, doors, etc.



  • The time variation of the heat sources and sinks, such as daily, weekly, seasonal, etc.



  • The safety factor to account for uncertainties and contingencies.



The refrigeration load can be estimated by using various methods, such as:



  • The heat balance method, which equates the heat gain and heat loss of the space or the substance.



  • The cooling load temperature difference (CLTD) method, which uses tabulated values of CLTD for different types of spaces or substances.



  • The transfer function method (TFM), which uses mathematical models of heat transfer for different types of spaces or substances.



  • The computer simulation method, which uses software programs to simulate the thermal behavior of spaces or substances.



The methods of system design and optimization




the refrigeration system to meet the load requirements and the design criteria. The system design and optimization involves the following steps:



  • Selecting the type of refrigeration system and the refrigerant that best suit the application.



  • Selecting and sizing the components of the refrigeration system, such as the compressor, the condenser, the expansion device, and the evaporator.



  • Determining the operating conditions and parameters of the refrigeration system, such as the pressures, temperatures, mass flow rates, heat transfer rates, power consumption, etc.



  • Evaluating the performance and efficiency of the refrigeration system, such as the COP, the capacity, the heat rejection factor, the compression ratio, etc.



  • Optimizing the refrigeration system by adjusting the design variables and parameters to achieve the maximum COP, capacity, or minimum power consumption, cost, or environmental impact.



The examples of system design for different applications




To illustrate the process of system design and optimization, here are some examples of refrigeration systems for different applications:



  • A domestic refrigerator is a vapor compression system that uses R-134a as the refrigerant. It consists of a hermetic reciprocating compressor, a finned-tube air-cooled condenser, a capillary tube expansion device, and a plate-type evaporator. The design parameters are: cooling capacity = 0.5 kW; evaporator temperature = -10C; condenser temperature = 40C; compressor efficiency = 0.7; isentropic efficiency = 0.8. The performance and efficiency are: COP = 2.1; power consumption = 0.24 kW; heat rejection factor = 1.48; compression ratio = 6.5.



  • An ice-cream freezer is a vapor compression system that uses R-404A as the refrigerant. It consists of a semi-hermetic scroll compressor, a shell-and-tube water-cooled condenser, a thermostatic expansion valve (TEV), and a finned-tube air-cooled evaporator. The design parameters are: cooling capacity = 5 kW; evaporator temperature = -25C; condenser temperature = 35C; compressor efficiency = 0.8; isentropic efficiency = 0.85. The performance and efficiency are: COP = 2.8; power consumption = 1.79 kW; heat rejection factor = 1.36; compression ratio = 9.8.



  • A cold storage room is a vapor compression system that uses R-717 (ammonia) as the refrigerant. It consists of an open reciprocating compressor, a shell-and-coil water-cooled condenser, a float valve expansion device, and a coil-type evaporator. The design parameters are: cooling capacity = 50 kW; evaporator temperature = -5C; condenser temperature = 30C; compressor efficiency = 0.85; isentropic efficiency = 0.9. The performance and efficiency are: COP = 4.2; power consumption = 11.9 kW; heat rejection factor = 1.24; compression ratio = 4.7.



Chapter 4: Refrigeration Control and Operation




The principles of refrigeration control and its objectives




the operation of the refrigeration system and its components to achieve the desired cooling effect and to maintain the optimal performance and efficiency. The objectives of refrigeration control are:



  • To maintain the temperature and humidity of the cooling medium (such as air or water) within a specified range.



  • To prevent the overloading or underloading of the compressor and to avoid excessive pressure fluctuations.



  • To prevent the overheating or freezing of the refrigerant and to avoid liquid slugging or vapor locking.



  • To protect the refrigeration system and its components from damage or malfunction due to abnormal conditions, such as power failure, leakage, short circuit, etc.



The types of refrigeration control devices and their operation




Refrigeration control devices are the instruments or mechanisms that measure, monitor, adjust, or regulate the operation of the refrigeration system and its components. Some of the common types of refrigeration control devices are:



  • A thermostat is a device that senses the temperature of the cooling medium and controls the on-off cycle of the compressor or the refrigerant flow rate.



  • A pressure switch is a device that senses the pressure of the refrigerant and controls the on-off cycle of the compressor or the operation of other devices, such as fans, pumps, valves, etc.



  • A flow switch is a device that senses the flow rate of the refrigerant or the cooling medium and controls the operation of other devices, such as pumps, valves, etc.



  • A solenoid valve is a device that opens or closes an electrically operated valve to control the flow of refrigerant or cooling medium.



  • A TEV is a device that regulates the flow of refrigerant to the evaporator based on the superheat (the difference between the actual and saturation temperatures) of the refrigerant at the outlet of the evaporator.



  • An automatic expansion valve (AEV) is a device that regulates the flow of refrigerant to the evaporator based on the pressure difference between the inlet and outlet of the evaporator.



the flow of refrigerant to the evaporator by its small diameter and length.


  • A float valve is a device that regulates the flow of refrigerant to the evaporator based on the liquid level in a reservoir or a separator.



The troubleshooting and maintenance of refrigeration systems




Troubleshooting is the process of identifying and correcting the problems or faults that occur in the refrigeration system and its components. Maintenance is the process of inspecting, cleaning, repairing, or replacing the refrigeration system and its components to prevent or reduce the occurrence of problems or faults. Troubleshooting and maintenance are essential for ensuring the safe, reliable, and efficient operation of the refrigeration system. Some of the common troubleshooting and maintenance procedures are:



  • Checking the electrical connections, fuses, switches, relays, etc. for any damage, loose wires, short circuits, etc.



  • Checking the refrigerant level, pressure, temperature, quality, leakage, etc. for any abnormality, deviation, contamination, etc.



  • Checking the compressor for any noise, vibration, overheating, oil level, etc.



  • Checking the condenser for any fouling, scaling, corrosion, blockage, etc.



  • Checking the expansion device for any clogging, sticking, hunting, etc.



  • Checking the evaporator for any frosting, icing, flooding, etc.



  • Checking the control devices for any malfunction, misadjustment, calibration error, etc.



  • Cleaning the heat transfer surfaces of the condenser and evaporator to remove any dirt, dust, oil, etc.



  • Lubricating the moving parts of the compressor and other devices to reduce friction and wear.



  • Replacing or repairing any damaged or worn-out parts of the refrigeration system and its components.



Conclusion




systems, components, design, control, and operation of refrigeration processes. It explains the concepts in a clear and concise manner, using diagrams, tables, charts, examples, problems, and solutions. It provides a comprehensive and up-to-date treatment of refrigeration topics, such as refrigerants, refrigeration cycles, refrigeration systems, refrigeration components, refrigeration load calculations, refrigeration system design, refrigeration control, and refrigeration operation and maintenance. It reflects the latest standards, codes, and regulations related to refrigeration, such as ASHRAE, ANSI, UL, and EPA. It is suitable for both beginners and advanced learners, as it covers the fundamentals as well as the advanced topics of refrigeration.


If you want to learn more about refrigeration engineering or to download a PDF version of this book for free, you can visit the following link: [1]. We hope you found this article helpful and informative. Thank you for reading!


FAQs




Here are some frequently asked questions about the book Principles of Refrigeration by Roy J. Dossat:



  • Who is the target audience of this book?



This book is intended for students, teachers, engineers, technicians, and anyone who is interested in learning about refrigeration engineering.


  • What are the prerequisites for reading this book?



This book assumes that the reader has a basic knowledge of physics, chemistry, mathematics, and engineering. However, it also provides a review of the relevant concepts in the appendices.


  • What are the main advantages of this book over other books on refrigeration?



This book has several advantages over other books on refrigeration, such as:


  • It covers both the theoretical and practical aspects of refrigeration engineering.



tables, charts, examples, problems, and solutions.


  • It provides a comprehensive and up-to-date treatment of refrigeration topics, such as refrigerants, refrigeration cycles, refrigeration systems, refrigeration components, refrigeration load calculations, refrigeration system design, refrigeration control, and refrigeration operation and maintenance.



  • It reflects the latest standards, codes, and regulations related to refrigeration, such as ASHRAE, ANSI, UL, and EPA.



  • It is suitable for both beginners and advanced learners, as it covers the fundamentals as well as the advanced topics of refrigeration.



How can I download a PDF v


About

Welcome to the group! You can connect with other members, ge...

Members

  • drickett110
  • hawaii pools
    hawaii pools
  • Anjali Kukade
    Anjali Kukade
  • Shivani Patil
    Shivani Patil
  • Ishita Pataliya
    Ishita Pataliya
Group Page: Groups_SingleGroup
bottom of page