Classical
Thermodynamics
Russell and Adebiyi
(An Overview)
Classical
Thermodynamics
This book was written to serve as an undergraduate textbook in classi-
cal thermodynamics for engineering students. The text is for students
who have had basic calculus (including differentiation and integration),
physics, and the fundamentals of chemistry. The text is designed for a
two-semester course sequence, or for an introductory one-semester course.
Our purposes in writing this book are (1) to explain fundamental
concepts and principles of thermodynamics explicitly and to provide begin-
ning undergraduate students with adequate information for a reasonable
understanding of thermodynamics,(2) to provide a more comprehensive treat-
ment of the second law of thermodynamics than is found in most beginning
texts and to base this treatment on the most recent research in the field,
and (3) to provide software that aids in a physical understanding of the
problems while minimizing nonproductive time spent by students in working
problems.
The pedagogy for the text is based on approximately 20 years of
experience by each of the authors in teaching thermodynamics to a wide
variety of students. Important terms and concepts are introduced early
(many in Chapter 1), and then fully explained and illustrated later at
the appropriate time. These terms and concepts are then used where app-
licable throughout the remainder of the text in order to reinforce the
learning process. As a result of this approach the text provides more
in-depth treatment of many difficult concepts, such as exergy, than most
other texts. A systematic approach to problem solving is also outlined in
Chapter 1 and used throughout the text.
Organization
The book is organized into 15 chapters, the first nine of which cover
the fundamentals of thermodynamics, while the remaining six chapters
present applications that are common in engineering. The foundation for
the entire text is laid in the first two chapters. An overview of thermo-
dynamics is given in Chapter 1 where the importance of thermodynamics and
its relationship to our use of energy resources are discussed. Chapters 1
and 2 also provide overview of the concepts of thermodynamics. Concepts
are an essential part of any science, and in the case of thermodynamics,
experience has shown that this is an area where students have difficulty.
Several examples, drawn from everyday experiences, are used to help
students achieve a good understanding of the concepts and also gain an
early appreciation of the relevance of thermodynamics to the everyday
needs of society. Special emphasis is given throughout the text to phys-
ical systems and physical understandings. Fundamental laws and principles
are explained with explicit statements, sometimes repeated in different
forms, and illustrated with familiar systems in order to assist students
in understanding the important principles and concepts. Particular atten-
tion is given throughout the text to the definition of system boundaries
and to the interactions across these boundaries.
Chapters 3 and 4 deal with the properties of a class of substances
known as pure substances. Properties of common substances are provided
both in tabular form and on computer disk for use with the text. Four
computer programs (for IBM or an IBM- compatible PC) were developed to
accompany this text and are contained on the ThermoPropsTM--
Thermodynamics Properties Data Finder disk found at the back of this
textbook. The four programs include STEAM (for the properties of ice,
water, and steam), R22 (for refrigerant-22 properties), GAS (for ideal
gases CO2, CO, O2, N2, H2O, H2, air, and CH4 encountered in combustion
processes), and PSY (for moist air,water, and steam properties needed in
the analysis of air conditioning processes). Graphical and tabular outputs
are provided by the programs, and the graphical outputs are designed
specifically to increase the student's understanding of the system.
Problems at the end of the chapter that are more easily solved using the
computer programs are identified with a disk symbol next to each problem.
These computer programs are not intended to displace the need for students
to be able to read tables of properties. In later chapters, however,
students are encouraged to use ThermoProps, especially whenever several
property values are to be determined, so that the focus can be placed on
application of thermodynamic principles to the solution of a problem.
Chapter 5 gives a more detailed treatment of work and heat
following the introduction provided in Chapters 1 and 2. This expanded
treatment is important to considerations of the first and second laws of
thermodynamics. The two laws are often regarded as the pillars of thermo-
dynamics: the first speaks of energy and its conservation (quantity),
while the second law deals with the quality aspect of energy. The first
law of thermodynamics is discussed in Chapter 6. The exposition of the
first law of thermodynamics essentially follows the classical tradition
of Poincare and Planck. Starting with a formal statement of the first
law of thermodynamics in terms of net heat and net work in a cyclic
process, corollaries are established including the important deduction
that the thermodynamic concept of energy derives solely from the first
law of thermodynamics. Applications of the first law of thermodynamics
to nonflow processes (for closed systems) and flow processes (for open
systems or control volumes) are explained, and several examples are
provided from everyday experiences to demonstrate the importance of the
first law analysis to the carrying out of an energy balance whenever a
system (closed or open) interacts with its environment.
The second law of thermodynamics occupies a central place in
thermodynamics and accordingly is treated in a comprehensive manner
consistent with the most recent research in the field. Formal statements
of the law are presented and discussed in Chapter 7, followed by a syste-
matic development of the corollaries of the law. Chapter 8 is devoted
entirely to consideration of entropy, which is to the second law what
energy is to the first law. (Energy and entropy are both derived proper-
ties in the sense that their existence can only be inferred as corolla-
ries of the respective laws.) The treatment of the second law in Chapter 8
includes the use of the entropy concept for the evaluation of processes
and for the determination of "waste" or "energy degradation" taking
place in real processes. In Chapter 9, another second law concept, exergy
(or availability ) is introduced along with a development of procedures for
utilizing the concept in performance evaluation of systems (open or closed).
The term exergy has been used in preference to availability to conform
with the international trend.
It should be noted that several applications of thermodynamics in
the other sciences are often limited to a first law analysis. However,
questions relating to efficiency and evaluation of performance, or the
direction of physical and chemical processes, for example, require a
second law analysis. There is much contemporary concern about "conserva-
tion" and making the available energy resources last longer by using
more efficient energy systems. This reality is part of the reason for the
prominent place accorded the second law of thermodynamics in this text.
After the detailed exposition given to the law in Chapters 7 to 9, the
various applications to systems in Chapter 10 to 15 provide ample demonst-
ration of how to carry out a complete thermodynamic analysis based on both
the first and second laws of thermodynamics. Second law analyses are
illustrated for a broad range of applications, including vapor and gas
cycles (Chapter 10), refrigeration cycles (Chapter 11), psychrometrics
(Chapter 13), combustion processes (Chapter 14), and chemical equilibria
(Chapter 15). The optimum thermodynamic cycle is discussed, and an expla-
nation is given to differentiate optimum cycles from ideal cycles.
The fact that the Carnot cycle is not the optimum cycle for a real heat
power plant that receives heat from combustion gases is demonstrated and
explained.
Pedagogy
Several special pedagogical features are included in the text. A list
of key concepts at the beginning of each chapter introduces the, material,
while a chapter-end summary of key concepts and ideas provides a handy
reference for review. Review questions at the end of each chapter re-
inforce key concepts and allow students to test their comprehension of
material just learned. Significant terms are boldfaced or italicized for
emphasis.
Worked examples, followed by exercises, appear throughout the text,
so students have models to guide them through new material. The section
exercises, which include answers, give students more opportunities to
check their progress and build on acquired knowledge as they move through
each section and chapter. The problems at the end of each chapter are
graded according to three levels of difficulty (low, average, and high),
motivating students to challenge their abilities as they progress through
the problem sets. Open-ended design problems appear after each problem set
in the applications chapters, 10 through 15. Students, given a realistic
engineering situation, are asked either to redesign the system to meet
specified goals or are asked to analyze the system's capabilities through
a series of questions. Also integrated throughout, are problems related
to safety. A total of 1050 problems and exercises are provided in the text.
Answers to selected end-of-chapter problems are given at the back of the
book.
Problems, examples, and data are given for both the Système
International d'Unites (SI) and the United States Customary System of
units (USCS), but the unit systems are not mixed in a specific problem.
Although it is apparent that the United States and all other major indust-
rialized countries are moving to SI, the change is not yet complete and it
is appropriate for students to develop the capability to deal with both
systems. However, if an instructor wishes, he or she can generally use
strictly one system or the other throughout.
Package
The following supplements are provided free to adopters.
Instructor's Manual with Solutions and Transparency Masters. Complete
solutions to all end-of-chapter problems are provided. In addition,
there are 100 transparency masters of selected figures enlarged from
the text.
ThermoPropsTM --Thermodynamics Properties Data Finder. On disk for IBM-
compatible PCs, this software is enclosed with every copy of the text.
The four programs presented include STEAM (for the properties of ice,
water, and steam), R22 (for refrigerant-22 proper- ties), GAS (for ideal
gases CO2, CO, O2, N2, H2O, H2, air, and CH4 encountered in combustion
processes), and PSY (for moist air, water, and steam properties needed
in the analysis of air conditioning processes). On-screen graphs and
tables offer easy-to-read results, allowing students to concentrate more
on problem solving than on time- consuming data searches.
Acknowledgments We wish to acknowledge the following individuals who assisted in various stages of the review process of the text:
Charles W. Bouchillon, Mississippi State University
C. T. Carley, Mississippi State University
Alan J. Chapman, Rice University
Kenneth D. Kihm, Texas A&M University
Alan A. Komhauser, Virginia Polytechnic Institute and State University
Robert J. Krane, University of Tennessee, Knoxville
Blaine 1. Leidy, University of Pittsburgh
D. C. Look, Jr., University of Missouri-Rolla
John J. McGrath, Michigan State University
Ronald S. Mullisen, California Polytechnic State University, San Luis Obispo
Lar Roe, Virginia Polytechnic Institute and State University
George Tsatsaronis, Tennessee Technological University
Thomas W. Weber, State University of New York at Buffalo
William J. Wepfer, Georgia Institute of Technology
William M. Worek, University of Illinois at Chicago
CONTENTS
CHAPTER 1 Introduction 1
1.1 Introduction 1
1.2 Basic Concepts and Thermodynamic Modeling 5
1.3 Fundamental Laws of Thermodynamics 17
1.4 Typical Thermodynamic Systems and Processes 22
1.5 Relationship of Thermodynamics to Energy Needs 29
1.6 Systematic Procedure for Solving Thermodynamic Problems 35
1.7 Summary 36
References 37
Questions 38
Problems 39
CHAPTER 2 Thermodynamic Quantities and Units 44
2.1 Introduction 44
2.2 Thermodynamic Properties 45
2.3 Work and Heat Interactions 50
2.4 Dimensions and Units 57
2.5 Summary 71
References 71
Questions 72
Problems 73
CHAPTER 3 Properties of a Pure Substance 80
3.1 Introduction 80
3.2 Specification of the Thermodynamic State of Systems 81
3.3 Pure Substances and the Two-Property Rule 84
3.4 pvT Relationships for Pure Substances 88
3.5 Tables of Thermodynamic Properties 100
3.5.1 Superheated Vapor Region 101
3.5.2 Saturated Liquid - Vapor and the Wet Vapor Region 104
3.5.3 Compressed or Subcooled Liquid Region 108
3.5.4 Saturated Solid - Vapor Mixture Region 112
3.5.5 Compressed Solid Region 113
3.6 Systematic Procedure for Reading Property Tables 115
3.7 Computer Routines for Thermodynamic Properties 116
3.8 Summary 117
References 118
Questions 118
Problems 119
CHAPTER 4 Ideal Gas and Real Gas 125
4.1 Definition of Ideal Gas 125
4.2 Comparison of Ideal Gas with Real Gas 128
4.3 Internal Energy and Enthalpy of Ideal Gas 131
4.4 Specific Heats of Ideal Gas 131
4.5 Ideal Gas Tables and Computer Routines 136
4.6 Principle of Corresponding States and Compressibility Charts 136
4.7 Real Gas Equations of State 139
4.7.1 Van der Waals Equation 140
4.7.2 Beattie - Bridgeman Equation 141
4.7.3 Redlich - Kwong Equation 143
4.7.4 Virial Form of the Equation of State 145
4.8 Summary 147
References 148
Questions 148
Problems 149
CHAPTER 5 Processes, Work, and Heat 154
5.1 Introduction 154
5.2 Processes 155
5.3 Work 158
5.3.1 Definitions of Work 158
5.3.2 Mechanical Displacement Work 164
5.3.3 Mechanical Shaft Work 178
5.3.4 Electrical Work 180
5.3.5 Other Types of Work 182
5.4 Heat 182
5.4.1 Definition of Heat 183
5.4.2 Heat from a Phenomenological Perspective 184
5.4.3 Comparison of Heat with Work 189
5.5 Summary 190
References 190
Questions 191
Problems 193
CHAPTER 6 The First Law of Thermodynamics 199
6.1 Introduction 199
6.2 Producing a Heating Effect by Doing Work 199
6.3 First Law of Thermodynamics for a Closed System 201
6.4 Examples of First Law Applied to a Closed System 207
6.5 First Law of Thermodynamics for a Control Volume (Open System) 217
6.6 Examples of First Law Applied to a Control Volume 224
6.7 Summary 236
References 237
Questions 237
Problems 239
CHAPTER 7 The Second law of Thermodynamics 249
7.1 Introduction 249
7.2 Reservoirs, Heat Engines, and Refrigerators 251
7.3 Statements of the Second Law 256
7.4 Perpetual Motion Machines 259
7.5 Reversibility and Irreversibility 259
7.6 Carnot Cycle 261
7.7 Some Corollaries of the Second Law 264
7.7.1 Carnot Cycle Engines Operating Between Two Reservoirs 264
7.7.2 Corollary Concerning Thermodynamic Temperature Scale 265
7.7.3 Efficiency of Carnot Devices 268
7.7.4 Inequality of Clausius 269
7.8 Summary 274
References 275
Questions 275
Problems 277
CHAPTER 8 Entropy 283
8.1 Introduction 283
8.2 Entropy as a Property 284
8.3 Entropy and the Third Law of Thermodynamics 286
8.4 The Combined First and Second Law 286
8.5 Entropy Change of a Pure Substance 288
8.6 Isentropic Process 293
8.7 Carnot Cycle T-S Diagram 304
8.8 The Principle of Increase in Entropy for a Closed System 308
8.9 The Principle of Increase in Entropy fora Control Volume 314
8.10 Efficiency of Devices 328
8.11 Summary 333
References 333
Questions 333
Problems 334
CHAPTER 9 Thermodynamic Availability 343
9.1 Introduction 343
9.2 Exergy in Nonflow Processes 351
9.2.1 Expressions for the Exergy of a Closed System 351
9.2.2 Equivalence Between Mechanical Energy Forms and Exergy 363
9.2.3 Flow of Exergy (XQ) Associated with Heat Flow (Q) 366
9.2.4 Exergy Consumption and Entropy Generation 376
9.3 Exergy in Steady-Flow Processes 380
9.3.1 Expressions for Energy in Steady-Flow Processes 380
9.3.2 Energy Dissipation and Entropy Generation 388
9.3.3 Alternative Expressions for the Energy Flow Rate Associated
with a Flow of Mass 389
9.4 Exergy Flow and Optimum Thermodynamic Cycles 392
9.5 Summary 397
References 398
Questions 399
Problems 400
CHAPTER 10 Thermodynamics of Heat Engine Cycles 407
10.1 Introduction 407
10.2 Thermodynamic Modeling of Heat Engines 410
10.2.1 Ideal Heat Engine Cycles 410
10.2.2 Performance Criteria for Heat Engines 413
10.2.3 Procedure for Heat Engine Cycle Analysis 420
10.3 Vapor Power Cycles 421
10.3.1 Thermodynamic Analysis of the Basic Rankine Cycle 422
10.3.2 Modifications to the Basic Rankine Cycle 432
10.4 Gas (Turbine) Power Cycles 448
10.4.1 Simple Gas Turbine 449
10.4.2 Modifications to the Basic Gas Turbine Cycle 464
10.5 Reciprocating Internal Combustion Engines 467
10.5.1 Principle of Operation 467
10.5.2 Air Standard Otto and Diesel Cycles 471
10.6 Optimum Power Cycles 492
10.7 Summary 504
References 505
Questions 506
Problems 506
CHAPTER 11 Refrigeration Cycles 521
11.1 Introduction 521
11.2 Principles of Refrigeration 521
11.2.1 Evaporative Cooling Principle 522
11.2.2 Gas Refrigeration Cycles 525
11.2.3 Thermoelectric Refrigeration 527
11.3 Thermodynamic Evaluation of Refrigeration Cycles 527
11.3.1 Performance Criteria 527
11.3.2 Thermodynamic Modeling of Refrigeration and Heating Systems 529
11.4 Vapor Compression Cycles 535
11.5 Absorption Refrigeration Cycles 545
11.6 Air Standard Gas Refrigeration Cycle 546
11.7 Second Law Considerations 549
11.8 Summary 552
References 553
Questions 554
Problems 555
CHAPTER 12 Thermodynamic Property Relationships 564
12.1 Introduction 564
12.2 Mathematical Considerations 565
12.3 Maxwell Relations 568
12.4 Specific Heat (at constant p, constant v) 570
12.5 Enthalpy, Internal Energy, and Entropy 573
12.6 Clapeyron Equation 576
12.7 Physical Coefficients 578
12.8 Development of Property Tables from Experimental Data
for Real Substances 580
12.9 Generalized Charts for Real Gases 583
12.9.1 Chart for Enthalpy 584
12.9.2 Chart for Entropy 586
12.10 Summary 588
References 588
Questions 589
Problems 589
CHAPTER 13 Nonreactive Ideal Gas Mixtures 593
13.1 Introduction 593
13.2 Additive Laws for Ideal gas Mixtures 598
13.2.1 pVT Relationship for Ideal Gas Mixtures 598
13.2.2 Gibbs-Dalton Law for Ideal Gas Mixtures 604
13.3 Air-Vapor Mixtures 616
13.3.1 Humidity Parameters 616
13.3.2 Psychrometric Chart 627
13.3.3 Thermodynamics of Psychrometric Processes 632
13.3.4 Computer Code PSY for the Analysis of Psychrometric Processes 641
13.4 Summary 646
References 647
Questions 647
Problems 648
CHAPTER 14 Combustion 655
14.1 Introduction 655
14.2 Conservation of Mass and Atomic Species 657
14.3 Stoichiometry of Reactions 659
14.4 Actual Combustion Processes 668
14.5 Thermodynamic Analysis of Combustion Processes 672
14.6 First Law Analysis of Combustion Processes 675
14.6.1 Enthalpy of Formation 675
14.6.2 Enthalpy of Chemical Substances 678
14.6.3 Enthalpy of Reaction and Heating Values 680
14.6.4 Application of the First Law to Flow Processes 684
14.6.5 Adiabatic Flame Temperature 691
14.7 Second Law Analysis 694
14.7.1 Entropy Change for Reacting Systems 695
14.7.2 Exergy Analysis For Reacting Systems 699
14.8 Summary 707
References 708
Questions 709
Problems 709
CHAPTER 15 Chemical Equilibrium 718
15.1 Introduction 718
15.2 Equilibrium Criteria 718
15.3 Equilibrium and the Chemical Potential 723
15.4 Reaction Equilibrium 725
15.5 Equilibrium Constant 728
15.6 Equilibrium Compositions 731
15.7 Maximizing Exergy Delivery from Chemical Reactions 744
15.8 Summary 748
References 749
Questions 749
Problems 749
APPENDIX A Property Tables and Constants in SI Units A1
APPENDIX B Property Tables and Constants in USCS Units A57
APPENDIX C Generalized Charts and Psychrometric Charts A129
APPENDIX D Computer Codes for the Thermodynamic Properties of Common
Substances Encountered in Engineering Applications A139
Answers to Selected Problems A153
Index I1