Thermodynamics from Concepts to Applications Second Edition bY Shavit and Chaim Gutfinger

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Thermodynamics from Concepts to Applications Second Edition bY Shavit and Chaim Gutfinger

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Contents

Preface for Students ……………………………………………………………………………………………. xi
Preface for Instructors ………………………………………………………………………………………. xiii
Authors …………………………………………………………………………………………………………….. xv
1 Introduction ………………………………………………………………………………………………..1
1.1 Historical Background …………………………………………………………………………………..1
1.2 Applications of Thermodynamics ………………………………………………………………….3
2 Basic Concepts……………………………………………………………………………………………..5
2.1 Thermodynamic System ………………………………………………………………………………..6
2.2 Properties and States ……………………………………………………………………………………..7
2.2.1 Identical States …………………………………………………………………………………..7
2.2.2 Path ……………………………………………………………………………………………………7
2.2.3 Interaction …………………………………………………………………………………………7
2.2.4 Process ………………………………………………………………………………………………8
2.2.5 Cycle ………………………………………………………………………………………………….8
2.2.6 General Defi nition of Property ………………………………………………………….8
2.2.7 Derived Properties …………………………………………………………………………….9
2.2.8 Extensive and Intensive Properties ……………………………………………………9
2.2.9 Quantity of Matter …………………………………………………………………………….9
2.2.10 Specifi c Property …………………………………………………………………………….. 10
2.2.11 Density ……………………………………………………………………………………………. 10
2.3 Some Characteristics of Properties ……………………………………………………………… 11
2.4 Equilibrium …………………………………………………………………………………………………12
2.5 Stable Equilibrium ………………………………………………………………………………………. 13
2.5.1 Other Types of Equilibria ……………………………………………………………….. 14
2.6 Mutual Equilibrium ……………………………………………………………………………………. 15
2.7 Zeroth Law of Thermodynamics ………………………………………………………………… 15
Problems ………………………………………………………………………………………………………………. 16
3 Work, Energy, and Heat: First Law of Thermodynamics ……………………………. 21
3.1 Work in Mechanical Systems ………………………………………………………………………. 21
3.2 Work in Thermodynamic Systems ………………………………………………………………. 21
3.2.1 Example: Where Work Cannot Be Identifi ed ……………………………………23
3.3 Measure of Work …………………………………………………………………………………………. 24
3.4 Adiabatic Process ………………………………………………………………………………………… 24
3.5 Work in Nonadiabatic Processes ………………………………………………………………….25
3.6 Work at Moving Boundary …………………………………………………………………………..25
3.7 Work of Compressible System ……………………………………………………………………..26
3.8 Quasistatic Process and Quasistatic Work ……………………………………………………27
3.9 First Law of Thermodynamics……………………………………………………………………..29
3.10 Work, Heat, and Energy ………………………………………………………………………………. 31
3.11 Temperature ……………………………………………………………………………………………….. 32
3.12 Units and Dimensions …………………………………………………………………………………33
Problems ……………………………………………………………………………………………………………….35
4 Simple Systems ………………………………………………………………………………………….43
4.1 Independent and Dependent Properties ………………………………………………………43
4.2 State Principle ………………………………………………………………………………………………43
4.3 Simple Systems …………………………………………………………………………………………….44
4.4 Equations of State ………………………………………………………………………………………..45
4.5 Internal Energy ……………………………………………………………………………………………46
4.6 Basic Processes in Simple Systems ……………………………………………………………….48
4.6.1 Constant-Volume Process…………………………………………………………………48
4.6.2 Constant-Pressure Process ……………………………………………………………….50
4.7 Pure Substances …………………………………………………………………………………………..54
4.8 Intensive State ……………………………………………………………………………………………..54
4.9 Phases ………………………………………………………………………………………………………….54
4.10 Properties of Pure Substance ……………………………………………………………………….54
4.10.1 The T–p Diagram ……………………………………………………………………………..55
4.10.2 The p–v Diagram ……………………………………………………………………………..56
4.11 Tables of Thermodynamic Properties …………………………………………………………..58
4.11.1 Structure of the Steam Tables …………………………………………………………..58
4.11.2 Using Steam Tables ………………………………………………………………………….59
4.11.3 Interpolation ……………………………………………………………………………………60
4.11.4 Engineering Equation Solver Software …………………………………………….64
4.12 First Law of Thermodynamics for Simple Systems ………………………………………65
4.12.1 Methodology for Solving Problems …………………………………………………65
4.13 Summary of Equations for Simple Systems ………………………………………………….69
Problems ………………………………………………………………………………………………………………. 70
5 Ideal Gas ……………………………………………………………………………………………………83
5.1 Defi nition of an Ideal Gas …………………………………………………………………………….83
5.2 Internal Energy and Enthalpy of an Ideal Gas ……………………………………………..85
5.3 Ideal Gas with Constant Specifi c Heat …………………………………………………………86
5.4 Quasistatic Processes in an Ideal Gas …………………………………………………………..88
5.5 Polytropic Process ………………………………………………………………………………………..90
5.6 Applications of First Law to Ideal Gas Systems ……………………………………………92
5.7 Summary of Equations for an Ideal Gas ………………………………………………………95
Problems ……………………………………………………………………………………………………………….96
6 Control Volume ……………………………………………………………………………………….. 107
6.1 Transition from System to Control Volume ……………………………………………….. 107
6.2 Conservation of Mass for a Control Volume ……………………………………………… 109
6.3 First Law of Thermodynamics for a Control Volume ………………………………… 110
6.4 Steady State Processes ……………………………………………………………………………….. 112
6.4.1 Nozzles and Diffusers …………………………………………………………………… 114
6.4.2 Throttling Devices ………………………………………………………………………… 115
6.4.3 Turbines, Compressors, and Pumps ………………………………………………. 117
6.4.4 Heat Exchangers ……………………………………………………………………………. 118
6.5 Unsteady State Processes in Control Volumes …………………………………………… 120
6.6 One-Port Control Volumes ………………………………………………………………………… 120
6.6.1 Charging a Vessel………………………………………………………………………….. 121
6.6.2 Discharging a Vessel …………………………………………………………………….. 124
6.7 Summary of Equations for a Control Volume ……………………………………………… 126
Problems …………………………………………………………………………………………………………….. 127
7 Heat Engines and Second Law of Thermodynamics ………………………………… 141
7.1 Heat Engines …………………………………………………………………………………………….. 141
7.2 Effi ciency of Heat Engines…………………………………………………………………………. 143
7.3 Second Law of Thermodynamics ………………………………………………………………. 146
7.4 Reversibility ………………………………………………………………………………………………. 147
7.5 Internally Reversible Process …………………………………………………………………….. 150
7.6 Carnot Cycle ……………………………………………………………………………………………… 151
7.7 Effi ciency and the Reversible Engine ………………………………………………………… 152
7.8 Thermodynamic Temperature Scale ………………………………………………………….. 153
7.9 Summary of Equations for Heat Engines and Second Law ……………………….. 156
Problems …………………………………………………………………………………………………………….. 157
8 Entropy ……………………………………………………………………………………………………. 163
8.1 Clausius Inequality …………………………………………………………………………………… 163
8.2 Entropy ……………………………………………………………………………………………………… 165
8.3 Entropy Change for Any Process ………………………………………………………………. 166
8.4 Principle of Increase of Entropy ………………………………………………………………… 167
8.5 Calculating Entropy Change in an Irreversible Process …………………………….. 168
8.6 Entropy Equations …………………………………………………………………………………….. 170
8.7 Using Entropy Data from Tables ……………………………………………………………….. 171
8.8 Entropy Change of an Ideal Gas ………………………………………………………………… 172
8.9 Entropy Change of an Incompressible Substance ………………………………………. 175
8.10 Entropy Diagrams …………………………………………………………………………………….. 176
8.11 Second Law Analysis of Control Volumes …………………………………………………. 180
Problems …………………………………………………………………………………………………………….. 181
9 Applications of Second Law of Thermodynamics ……………………………………. 199
9.1 Work in Expansion and Compression Processes ……………………………………….. 201
9.2 Effectiveness of Adiabatic Processes ………………………………………………………….206
9.3 Work and Heat in Isothermal Processes …………………………………………………….208
9.4 Effectiveness of Heat Exchangers ………………………………………………………………. 211
9.5 Test for the Impossibility of a Process ……………………………………………………….. 214
9.6 Summary of Equations ……………………………………………………………………………… 216
Problems …………………………………………………………………………………………………………….. 218
10 Availability, Exergy, and Irreversibility ………………………………………………….. 237
10.1 Available Work ………………………………………………………………………………………….. 237
10.2 Useful Work ………………………………………………………………………………………………. 241
10.3 Irreversibility ……………………………………………………………………………………………..242
10.4 Availability ………………………………………………………………………………………………..244
10.5 Control Volume Analysis: Exergy ……………………………………………………………… 248
Problems ……………………………………………………………………………………………………………..256
11 Power and Refrigeration Cycles ………………………………………………………………. 271
11.1 Rankine Cycle ……………………………………………………………………………………………272
11.2 Rankine Cycle Modifi cations …………………………………………………………………….. 276
11.2.1 Reheat Cycle ………………………………………………………………………………….. 276
11.2.2 Regenerative Cycle ………………………………………………………………………… 276
11.3 Brayton Cycle …………………………………………………………………………………………….. 281
11.3.1 Jet Engines ……………………………………………………………………………………..286
11.3.2 Regenerative Brayton Cycle ……………………………………………………………288
11.4 Cycles for Internal Combustion Engines …………………………………………………..290
11.5 Otto Cycle ………………………………………………………………………………………………… 291
11.6 Diesel Cycle ……………………………………………………………………………………………… 293
11.7 Dual Cycle ……………………………………………………………………………………………….. 294
11.8 Refrigeration Cycles …………………………………………………………………………………. 295
11.9 Basic Refrigeration Cycle ………………………………………………………………………….. 295
11.10 Internal Heat Exchanger ……………………………………………………………………………299
11.11 Refrigeration with Two-Stage Compression ………………………………………………304
11.12 Exergy Analysis ………………………………………………………………………………………..305
11.13 Summary of Equations …………………………………………………………………………….. 312
Problems …………………………………………………………………………………………………………….. 312
12 Ideal Gas Mixtures and Humid Air …………………………………………………………. 337
12.1 Basic Defi nitions for Gaseous Mixtures ……………………………………………………. 337
12.2 Equation of State for a Mixture of Ideal Gases …………………………………………..338
12.2.1 Dalton’s Model …………………………………………………………………………….339
12.2.2 Amagat’s Model …………………………………………………………………………..340
12.3 Properties of Mixtures of Ideal Gases ……………………………………………………….341
12.4 Gaseous Mixtures Involving a Condensable Component ………………………….344
12.5 Moist Air …………………………………………………………………………………………………..345
12.6 First Law for Moist Air ……………………………………………………………………………..346
12.7 Adiabatic Saturation …………………………………………………………………………………347
12.8 Wet-Bulb Temperature ………………………………………………………………………………349
12.9 Psychrometric Chart …………………………………………………………………………………349
12.10 Processes in Moist Air ……………………………………………………………………………… 351
12.10.1 Heating ………………………………………………………………………………………. 351
12.10.2 Cooling and Dehumidifi cation …………………………………………………… 351
12.10.3 Wetting Moist Air ……………………………………………………………………….353
12.10.4 Mixing of Moist Air Streams ……………………………………………………….355
12.11 Cooling Towers …………………………………………………………………………………………356
12.12 Exergy Analysis ………………………………………………………………………………………..358
12.13 Summary of Equations ……………………………………………………………………………..359
Problems …………………………………………………………………………………………………………….. 362
13 Thermodynamic Relations ………………………………………………………………………. 373
13.1 Some Mathematical Relations ………………………………………………………………….. 373
13.2 Maxwell Relations ……………………………………………………………………………………. 375
13.3 Clapeyron Equation …………………………………………………………………………………. 378
13.4 Specifi c Heats ……………………………………………………………………………………………380
13.5 Energy and Enthalpy Variations at Constant Temperature ……………………….382
13.6 Joule–Thomson Coeffi cient ……………………………………………………………………….383
13.7 Volume Change Coeffi cients ……………………………………………………………………..384
13.8 Summary of Equations …………………………………………………………………………….386
Problems ……………………………………………………………………………………………………………..387
14 Equations of State and Generalized Charts ……………………………………………… 393
14.1 van der Waals Equation ……………………………………………………………………………. 393
14.2 Dieterici Equation …………………………………………………………………………………….. 397
14.3 Empirical Equations of State …………………………………………………………………….. 398
14.4 Virial Form of Equation of State ………………………………………………………………..399
14.5 Thermodynamic Data from Equations of State …………………………………………399
14.6 Rule of Corresponding States ……………………………………………………………………404
14.7 Generalized Compressibility Chart …………………………………………………………..406
14.8 Generalized Enthalpy Chart ……………………………………………………………………..407
14.9 Generalized Entropy Chart ………………………………………………………………………. 410
14.10 Fugacity ……………………………………………………………………………………………………. 415
14.11 Summary of Equations …………………………………………………………………………….. 418
Problems ……………………………………………………………………………………………………………..420
15 Multicomponent Systems ………………………………………………………………………… 429
15.1 Intensive State …………………………………………………………………………………………..429
15.2 Phase ………………………………………………………………………………………………………..429
15.3 Components of a Phase …………………………………………………………………………….430
15.4 Partial Properties ………………………………………………………………………………………433
15.5 Gibbs Equation ………………………………………………………………………………………….437
15.6 Gibbs–Duhem Equation ……………………………………………………………………………440
15.7 Fugacity of a Component in a Solution ……………………………………………………..444
15.8 Standard State and Activity ………………………………………………………………………445
15.9 Fugacity Relations …………………………………………………………………………………….446
15.10 Partial and Specifi c Properties for Binary Phase ……………………………………….447
15.11 Mixing ………………………………………………………………………………………………………449
15.12 Summary of Equations …………………………………………………………………………….. 451
Problems ……………………………………………………………………………………………………………..454
16 Equilibrium …………………………………………………………………………………………….. 459
16.1 Maximum Entropy Criterion …………………………………………………………………….459
16.2 Minimum Energy Criterion ……………………………………………………………………… 461
16.3 Minimum Gibbs Free Energy …………………………………………………………………… 462
16.4 Chemical Potential …………………………………………………………………………………… 462
16.5 Gibbs Phase Rule ………………………………………………………………………………………464
16.6 Phase Equilibrium of Pure Substance ……………………………………………………….465
16.7 Equilibrium between Vapor Bubble and Liquid Phase …………………………….. 467
16.8 Equilibrium of Multicomponent Phases ……………………………………………………469
16.9 Summary of Equations ……………………………………………………………………………..469
Problems …………………………………………………………………………………………………………….. 470
17 Ideal Solutions ………………………………………………………………………………………… 473
17.1 Mixing Volume ………………………………………………………………………………………… 473
17.2 Enthalpy of Mixing …………………………………………………………………………………..475
17.3 Entropy of Mixing …………………………………………………………………………………….475
17.4 Binary Mixtures ……………………………………………………………………………………….. 476
17.5 Ideal Gas Mixtures …………………………………………………………………………………… 481
17.6 Phase Equilibrium in Multicomponent Mixtures ……………………………………..482
17.7 Equilibrium between Pure and Multicomponent Phase ……………………………487
17.8 Effect of Solute Concentration on Boiling Point …………………………………………489
17.9 Effect of Pressure on Solubility ………………………………………………………………… 491
17.10 Effect of Temperature on Solubility ………………………………………………………….. 492
17.11 Osmosis ……………………………………………………………………………………………………. 493
17.12 Exergy Analysis ……………………………………………………………………………………….. 495
Problems …………………………………………………………………………………………………………….. 496
18 Nonideal Solutions …………………………………………………………………………………..503
18.1 Henry’s Law ……………………………………………………………………………………………..503
18.2 Raoult’s Law ……………………………………………………………………………………………..504
18.3 Dilute Solutions ………………………………………………………………………………………..506
18.4 Binary Nonideal Solutions ………………………………………………………………………..506
18.5 Enthalpy of Mixing for Nonideal Binary Solutions …………………………………..508
18.6 Enthalpy Diagrams …………………………………………………………………………………..509
18.7 Absorption Refrigeration …………………………………………………………………………. 513
18.8 Summary of Equations …………………………………………………………………………….. 520
Problems …………………………………………………………………………………………………………….. 521
19 Chemical Reactions …………………………………………………………………………………. 525
19.1 Stoichiometry …………………………………………………………………………………………… 525
19.2 Fuel Combustion ……………………………………………………………………………………… 527
19.3 First Law for Chemical Reactions …………………………………………………………….. 529
19.3.1 Heating Value of Fuel ……………………………………………………………………536
19.4 Adiabatic Flame Temperature ………………………………………………………………….. 537
19.5 Enthalpy of Formation at Any Temperature …………………………………………….. 539
19.6 Free Energy of Formation at Any Temperature …………………………………………540
19.7 Chemical Equilibrium ……………………………………………………………………………… 541
19.8 Exergy Considerations ………………………………………………………………………………548
19.9 Summary of Equations …………………………………………………………………………….. 557
Problems ……………………………………………………………………………………………………………..560
Appendix ………………………………………………………………………………………………………… 575
Appendix A ………………………………………………………………………………………………………… 575
Appendix B …………………………………………………………………………………………………………. 612
Appendix C ………………………………………………………………………………………………………… 619
Answers to Selected Problems ………………………………………………………………………… 621
Bibliography ……………………………………………………………………………………………………. 637
Index ………………………………………………………………………………………………………………..643

Preface for Students

Thermodynamics is viewed by many students as a diffi cult subject. Although the mathematics
is rather simple, students fi nd the subject hard to understand. To improve comprehension,
the concepts encountered in thermodynamics should be clearly stated and
properly explained. We have, therefore, set out to write this book with the purpose of
presenting a text that is rigorous and accurate, yet relatively easy to grasp. We assume that
you have had at least one year of basic engineering education, including mathematics and
physics.
A student who completes a course based on this book should be able to think in clear
and correct thermodynamic terms, understand the basic principles of the subject, and gain
suffi cient knowledge to solve real engineering problems.
Some of the terms encountered in thermodynamics are also used in everyday life. Yet,
terms that may be used loosely in day-to-day language have a very specifi c meaning in
thermodynamics. Thermodynamics has historically developed around the concepts of
work, heat, energy, and temperature. In this book we defi ne each concept without ambiguity,
in a manner that is easy to understand.
Consider the following problem. An electric motor converts electrical energy into work
at an effi ciency of 95%, whereas an automobile engine converts fuel energy into work at an
effi ciency of less than 30%. Why is that so? Could the effi ciency be increased? If yes, what
is the highest effi ciency that the best engine could attain?
Now consider another problem. An air conditioner uses electricity to remove heat from
a cool room and transfer it to a warmer environment. Now if you turn around the air
conditioner, you could use it in the winter to remove heat from a colder environment and
transfer it into a warmer room. Such an arrangement is called a heat pump. Alternatively,
you could employ a simple resistance heater that uses electricity to heat the room directly.
What should you use and why? After studying thermodynamics, you will know the exact
answers to these and many other problems.