YUNUS A.CENGEL MICHAEL A.BOLES THERMODYNAMICS An Engineering Approach Eighth Edition
Graw Education THERMODYNAMICS:AN ENGINEERING APPROACH.EIGHTH EDITION Published by McGraw-Hill Education,2 Penn Plaza,New York,NY 10121.Copyright 2015 by McGraw-Hill Education.All rights reserved.Printed in the United States of America.Previous editions 2011,2008,2006,and 2002.No part of this publication may be reproduced or distributed in any form or by any means,or stored in a database or retrieval system,without the prior written consent of McGraw-Hill Education,including.but not limited to,in any network or other electronic storage or transmission,or broadcast for distance learning. Some ancillaries,including electronic and print components,may not be available to customers outside the United States. This book is printed on acid-free paper. 1234567890D0WD0W10987654 ISBN978-0-07-339817-4 MHD0-07-339817-9 Senior Vice President,Products Markets:Kurt L.Strand Vice President,General Manager:Marty Lange Vice President,Content Production Technology Services:Kimberly Meriwether David Global Publisher:Raghothaman Srinivasan Executive Editor:Bill Stenguist Developmental Editor:Lorraine K.Buczek Marketing Manager:Heather Wagner Director.Content Production:Terri Schiesl Content Project Manager:Jolynn Kilburg Buyer:Jennifer Pickel Cover Designer:Studio Montage,St.Louis,MO. Cover Photo:Photo provided by Alstom.2007 Bryon Paul McCartney www.photoworks312.com all rights reserved. Compositor:RPK Editorial Services,Inc. Typeface:10.5/12 Times LT Std Roman Printer:R.R.Donnelley About the Cover:A fully bladed GT26 gas turbine rotor at Alstom's rotor factory in Birr,Switzerland. All credits appearing on page or at the end of the book are considered to be an extension of the copyright page. Library of Congress Cataloging-in-Publication Data on File The Internet addresses listed in the text were accurate at the time of publication.The inclusion of a website does not indicate an endorsement by the authors or McGraw-Hill Education,and McGraw-Hill Education does not guarantee the accuracy of the information presented at these sites. www.mhhe.com
THERMODYNAMICS: AN ENGINEERING APPROACH, EIGHTH EDITION Published by McGraw-Hill Education, 2 Penn Plaza, New York, NY 10121. Copyright © 2015 by McGraw-Hill Education. All rights reserved. Printed in the United States of America. Previous editions © 2011, 2008, 2006, and 2002. No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written consent of McGraw-Hill Education, including, but not limited to, in any network or other electronic storage or transmission, or broadcast for distance learning. Some ancillaries, including electronic and print components, may not be available to customers outside the United States. This book is printed on acid-free paper. 1 2 3 4 5 6 7 8 9 0 DOW/DOW 1 0 9 8 7 6 5 4 ISBN 978-0-07-339817-4 MHID 0-07-339817-9 Senior Vice President, Products & Markets: Kurt L. Strand Vice President, General Manager: Marty Lange Vice President, Content Production & Technology Services: Kimberly Meriwether David Global Publisher: Raghothaman Srinivasan Executive Editor: Bill Stenquist Developmental Editor: Lorraine K. Buczek Marketing Manager: Heather Wagner Director, Content Production: Terri Schiesl Content Project Manager: Jolynn Kilburg Buyer: Jennifer Pickel Cover Designer: Studio Montage, St. Louis, MO. Cover Photo: Photo provided by Alstom. © 2007 Bryon Paul McCartney | www.photoworks312.com | all rights reserved. Compositor: RPK Editorial Services, Inc. Typeface: 10.5/12 Times LT Std Roman Printer: R. R. Donnelley About the Cover: A fully bladed GT26 gas turbine rotor at Alstom’s rotor factory in Birr, Switzerland. All credits appearing on page or at the end of the book are considered to be an extension of the copyright page. Library of Congress Cataloging-in-Publication Data on File The Internet addresses listed in the text were accurate at the time of publication. The inclusion of a website does not indicate an endorsement by the authors or McGraw-Hill Education, and McGraw-Hill Education does not guarantee the accuracy of the information presented at these sites. www.mhhe.com cen98179_fm_i-xxvi.indd iv 11/29/13 6:39 PM
Quotes on Ethics Without ethics,everything happens as if we were all five billion passengers on a big machinery and nobody is driving the machinery.And it's going faster and faster,but we don't know where. -Jacques Cousteau Because you're able to do it and because you have the right to do it doesn't mean it's right to do it. -Laura Schlessinger A man without ethics is a wild beast loosed upon this world. -Manly Hall The concern for man and his destiny must always be the chief interest of all technical effort.Never forget it among your diagrams and equations. -Albert Einstein Cowardice asks the question,'Is it safe?'Expediency asks the question,'Is it politic?'Vanity asks the question,'Is it popular?'But,conscience asks the question,'Is it right?'And there comes a time when one must take a posi- tion that is neither safe,nor politic,nor popular but one must take it because one's conscience tells one that it is right. -Martin Luther King,Jr To educate a man in mind and not in morals is to educate a menace to society. -Theodore Roosevelt Politics which revolves around benefit is savagery. -Said Nursi The true test of civilization is,not the census,nor the size of the cities,nor the crops,but the kind of man that the country turns out. -Ralph W.Emerson The measure of a man's character is what he would do if he knew he never would be found out. -Thomas B.Macaulay
Quotes on Ethics Without ethics, everything happens as if we were all five billion passengers on a big machinery and nobody is driving the machinery. And it’s going faster and faster, but we don’t know where. —Jacques Cousteau Because you’re able to do it and because you have the right to do it doesn’t mean it’s right to do it. —Laura Schlessinger A man without ethics is a wild beast loosed upon this world. —Manly Hall The concern for man and his destiny must always be the chief interest of all technical effort. Never forget it among your diagrams and equations. —Albert Einstein Cowardice asks the question, ‘Is it safe?’ Expediency asks the question, ‘Is it politic?’ Vanity asks the question, ‘Is it popular?’ But, conscience asks the question, ‘Is it right?’ And there comes a time when one must take a position that is neither safe, nor politic, nor popular but one must take it because one’s conscience tells one that it is right. —Martin Luther King, Jr To educate a man in mind and not in morals is to educate a menace to society. —Theodore Roosevelt Politics which revolves around benefit is savagery. —Said Nursi The true test of civilization is, not the census, nor the size of the cities, nor the crops, but the kind of man that the country turns out. —Ralph W. Emerson The measure of a man’s character is what he would do if he knew he never would be found out. —Thomas B. Macaulay cen98179_fm_i-xxvi.indd v 11/29/13 6:39 PM
ABOUT THE AUTHORS Yunus A.Cengel is Professor Emeritus of Mechanical Engineering at the University of Nevada,Reno.He received his B.S.in mechanical engineering from Istanbul Technical University and his M.S.and Ph.D.in mechanical engineering from North Carolina State University.His areas of interest are renewable energy, energy efficiency,energy policies,heat transfer enhancement,and engineering edu- cation.He served as the director of the Industrial Assessment Center (IAC)at the University of Nevada,Reno,from 1996 to 2000.He has led teams of engineering students to numerous manufacturing facilities in Northern Nevada and California to perform industrial assessments,and has prepared energy conservation,waste mini- mization,and productivity enhancement reports for them.He has also served as an advisor for various government organizations and corporations. Dr.Cengel is also the author or coauthor of the widely adopted textbooks Heat and Mass Transfer:Fundamentals and Applications(5th ed.,2015),Fluid Mechanics:Fundamentals and Applications (3rd ed.,2014),Fundamentals of Thermal-Fluid Sciences (4th ed.,2012),Introduction to Thermodynamics and Heat Transfer(2nd ed.,2008),and Differential Equations for Engineers and Scientists(Ist ed.,2013),all published by McGraw-Hill.Some of his textbooks have been translated into Chinese,Japanese,Korean,Thai,Spanish,Portuguese, Turkish,Italian,Greek,and French. Dr.Cengel is the recipient of several outstanding teacher awards,and he has received the ASEE Meriam/Wiley Distinguished Author Award for excellence in authorship in 1992 and again in 2000.Dr.Cengel is a registered Professional Engi- neer in the State of Nevada,and is a member of the American Society of Mechanical Engineers (ASME)and the American Society for Engineering Education(ASEE). Michael A.Boles is Associate Professor of Mechanical and Aerospace Engi- neering at North Carolina State University,where he earned his Ph.D.in mechani- cal engineering and is an Alumni Distinguished Professor.Dr.Boles has received numerous awards and citations for excellence as an engineering educator.He is a past recipient of the SAE Ralph R.Teetor Education Award and has been twice elected to the NCSU Academy of Outstanding Teachers.The NCSU ASME student section has consistently recognized him as the outstanding teacher of the year and the faculty member having the most impact on mechanical engineering students. Dr.Boles specializes in heat transfer and has been involved in the ana- lytical and numerical solution of phase change and drying of porous media. He is a member of the American Society of Mechanical Engineers (ASME) the American Society for Engineering Education (ASEE),and Sigma Xi Dr.Boles received the ASEE Meriam/Wiley Distinguished Author Award in 1992 for excellence in authorship
Yunus A. Çengel is Professor Emeritus of Mechanical Engineering at the University of Nevada, Reno. He received his B.S. in mechanical engineering from Istanbul Technical University and his M.S. and Ph.D. in mechanical engineering from North Carolina State University. His areas of interest are renewable energy, energy efficiency, energy policies, heat transfer enhancement, and engineering education. He served as the director of the Industrial Assessment Center (IAC) at the University of Nevada, Reno, from 1996 to 2000. He has led teams of engineering students to numerous manufacturing facilities in Northern Nevada and California to perform industrial assessments, and has prepared energy conservation, waste minimization, and productivity enhancement reports for them. He has also served as an advisor for various government organizations and corporations. Dr. Çengel is also the author or coauthor of the widely adopted textbooks Heat and Mass Transfer: Fundamentals and Applications (5th ed., 2015), Fluid Mechanics:Fundamentals and Applications (3rd ed., 2014), Fundamentals of Thermal-Fluid Sciences (4th ed., 2012), Introduction to Thermodynamics and Heat Transfer (2nd ed., 2008), and Differential Equations for Engineers and Scientists (1st ed., 2013), all published by McGraw-Hill. Some of his textbooks have been translated into Chinese, Japanese, Korean, Thai, Spanish, Portuguese, Turkish, Italian, Greek, and French. Dr. Çengel is the recipient of several outstanding teacher awards, and he has received the ASEE Meriam/Wiley Distinguished Author Award for excellence in authorship in 1992 and again in 2000. Dr. Çengel is a registered Professional Engineer in the State of Nevada, and is a member of the American Society of Mechanical Engineers (ASME) and the American Society for Engineering Education (ASEE). Michael A. Boles is Associate Professor of Mechanical and Aerospace Engineering at North Carolina State University, where he earned his Ph.D. in mechanical engineering and is an Alumni Distinguished Professor. Dr. Boles has received numerous awards and citations for excellence as an engineering educator. He is a past recipient of the SAE Ralph R. Teetor Edu cation Award and has been twice elected to the NCSU Academy of Outstanding Teachers. The NCSU ASME student section has consistently recognized him as the outstanding teacher of the year and the faculty member having the most impact on mechanical engineering students. Dr. Boles specializes in heat transfer and has been involved in the analytical and numerical solution of phase change and drying of porous media. He is a member of the American Society of Mechanical Engineers (ASME), the American Society for Engineering Education (ASEE), and Sigma Xi. Dr. Boles received the ASEE Meriam/Wiley Distinguished Author Award in 1992 for excellence in authorship. About the Authors cen98179_fm_i-xxvi.indd vi 11/29/13 6:39 PM
BRIEF CONTENTS CHAPTER ONE INTRODUCTION AND BASIC CONCEPTS 1 CHAPTER TWO ENERGY,ENERGY TRANSFER,AND GENERAL ENERGY ANALYSIS 51 CHAPTER THREE PROPERTIES OF PURE SUBSTANCES 111 CHAPTER FOUR ENERGY ANALYSIS OF CLOSED SYSTEMS 163 CHAPTER FIVE MASS AND ENERGY ANALYSIS OF CONTROL VOLUMES 213 CHAPTER SIX THE SECOND LAW OF THERMODYNAMICS 275 CHAPTER SEVEN ENTROPY 329 CHAPTER EIGHT EXERGY 421 CHAPTER NINE GAS POWER CYCLES 485 CHAPTER TEN VAPOR AND COMBINED POWER CYCLES 553 CHAPTER ELEVEN REFRIGERATION CYCLES 607 CHAPTER TWELVE THERMODYNAMIC PROPERTY RELATIONS 655 CHAPTER THIRTEEN GAS MIXTURES 687 CHAPTER FOURTEEN GAS-VAPOR MIXTURES AND AIR-CONDITIONING 725 CHAPTER FIFTEEN CHEMICAL REACTIONS 759 CHAPTER SIXTEEN CHEMICAL AND PHASE EQUILIBRIUM 805 CHAPTER SEVENTEEN COMPRESSIBLE FLOW 839 CHAPTER EIGHTEEN (WEB CHAPTER) RENEWABLE ENERGY
Brief Contents chapter one INTRODUCTION AND BASIC CONCEPTS 1 chapter two ENERGY, ENERGY TRANSFER, AND GENERAL ENERGY ANALYSIS 51 chapter three PROPERTIES OF PURE SUBSTANCES 111 chapter four ENERGY ANALYSIS OF CLOSED SYSTEMS 163 chapter five MASS AND ENERGY ANALYSIS OF CONTROL VOLUMES 213 chapter six THE SECOND LAW OF THERMODYNAMICS 275 chapter seven ENTROPY 329 chapter eight EXERGY 421 chapter nine GAS POWER CYCLES 485 chapter ten VAPOR AND COMBINED POWER CYCLES 553 chapter eleven REFRIGERATION CYCLES 607 chapter twelve THERMODYNAMIC PROPERTY RELATIONS 655 chapter thirteen GAS MIXTURES 687 chapter fourteen GAS–VAPOR MIXTURES AND AIR-CONDITIONING 725 chapter fifteen CHEMICAL REACTIONS 759 chapter sixteen CHEMICAL AND PHASE EQUILIBRIUM 805 chapter seventeen COMPRESSIBLE FLOW 839 chapter eighteen (web chapter) RENEWABLE ENERGY cen98179_fm_i-xxvi.indd vii 11/29/13 6:39 PM
viii THERMODYNAMICS APPENDIX 1 PROPERTY TABLES AND CHARTS (SI UNITS)897 APPENDIX 2 PROPERTY TABLES AND CHARTS (ENGLISH UNITS)947
viii THERMODYNAMICS appendix 1 PROPERTY TABLES AND CHARTS (SI UNITS) 897 appendix 2 PROPERTY TABLES AND CHARTS (ENGLISH UNITS) 947 cen98179_fm_i-xxvi.indd viii 11/29/13 6:39 PM
CONTENTS Preface xvii Engineering Equation Solver(EES)37 A Remark on Significant Digits 39 Summary 40 CHAPTER ONE References and Suggested Readings 41 Problems 41 INTRODUCTION AND BASIC CONCEPTS 1 CHAPTER TWO 1-1 Thermodynamics and Energy 2 Application Areas of Thermodynamics 3 ENERGY,ENERGY TRANSFER,AND GENERAL 1-2 Importance of Dimensions and Units 3 ENERGY ANALYSIS 51 Some SI and English Units 6 Dimensional Homogeneity 8 2-1 Introduction 52 Unity Conversion Ratios 9 2-2 Forms of Energy 53 1-3 Systems and Control Volumes 10 Some Physical Insight to Intemal Energy 55 1-4 Properties of a System 12 More on Nuclear Energy 56 Mechanical Energy 58 Continuum 12 2-3 Energy Transfer by Heat 60 1-5 Density and Specific Gravity 13 Historical Background on Heat 61 1-6 State and Equilibrium 14 2-4 Energy Transfer by Work 62 The State Postulate 15 Electrical Work 65 1-7 Processes and Cycles 15 2-5 Mechanical Forms of Work 66 The Steady-Flow Process 16 Shaft Work 66 1-8 Temperature and the Zeroth Law Spring Work 67 of Thermodynamics 17 Work Done on Elastic Solid Bars 67 Work Associated with the Stretching of a Liquid Film 68 Temperature Scales 18 Work Done to Raise or to Accelerate a Body 68 The International Temperature Scale of 1990 Nonmechanical Forms of Work 70 (1TS-90)20 1-9 Pressure 22 2-6 The First Law of Thermodynamics 70 Energy Balance 72 Variation of Pressure with Depth 24 Energy Change of a System,AEystem 72 1-10 Pressure Measurement Devices 27 Mechanisms of Energy Transfer,En and Eout 73 The Barometer 27 2-7 Energy Conversion Efficiencies 78 The Manometer 30 Efficiencies of Mechanical and Electrical Devices 82 Other Pressure Measurement Devices 33 2-8 1-11 Problem-Solving Technique 34 Energy and Environment 85 Ozone and Smog 86 Step 1:Problem Statement 34 Acid Rain 87 Step 2:Schematic 35 The Greenhouse Effect: Step 3:Assumptions and Approximations 35 Global Warming and Climate Change 88 Step 4:Physical Laws 35 Step 5:Properties 35 Topic of Special Interest:Mechanisms of Heat Step 6:Calculations 35 Transfer 91 Step 7:Reasoning,Verification,and Discussion 35 Summary 96 Engineering Software Packages 36 References and Suggested Readings 97 Problems 97
Preface xvii chapter one INTRODUCTION AND BASIC CONCEPTS 1 1–1 Thermodynamics and Energy 2 Application Areas of Thermodynamics 3 1–2 Importance of Dimensions and Units 3 Some SI and English Units 6 Dimensional Homogeneity 8 Unity Conversion Ratios 9 1–3 Systems and Control Volumes 10 1–4 Properties of a System 12 Continuum 12 1–5 Density and Specific Gravity 13 1–6 State and Equilibrium 14 The State Postulate 15 1–7 Processes and Cycles 15 The Steady-Flow Process 16 1–8 Temperature and the Zeroth Law of Thermodynamics 17 Temperature Scales 18 The International Temperature Scale of 1990 (ITS-90) 20 1–9 Pressure 22 Variation of Pressure with Depth 24 1–10 Pressure Measurement Devices 27 The Barometer 27 The Manometer 30 Other Pressure Measurement Devices 33 1–11 Problem-Solving Technique 34 Step 1: Problem Statement 34 Step 2: Schematic 35 Step 3: Assumptions and Approximations 35 Step 4: Physical Laws 35 Step 5: Properties 35 Step 6: Calculations 35 Step 7: Reasoning, Verification, and Discussion 35 Engineering Software Packages 36 Engineering Equation Solver (EES) 37 A Remark on Significant Digits 39 Summary 40 References and Suggested Readings 41 Problems 41 chapter two ENERGY, ENERGY TRANSFER, AND GENERAL ENERGY ANALYSIS 51 2–1 Introduction 52 2–2 Forms of Energy 53 Some Physical Insight to Internal Energy 55 More on Nuclear Energy 56 Mechanical Energy 58 2–3 Energy Transfer by Heat 60 Historical Background on Heat 61 2–4 Energy Transfer by Work 62 Electrical Work 65 2–5 Mechanical Forms of Work 66 Shaft Work 66 Spring Work 67 Work Done on Elastic Solid Bars 67 Work Associated with the Stretching of a Liquid Film 68 Work Done to Raise or to Accelerate a Body 68 Nonmechanical Forms of Work 70 2–6 The First Law of Thermodynamics 70 Energy Balance 72 Energy Change of a System, DEsystem 72 Mechanisms of Energy Transfer, Ein and Eout 73 2–7 Energy Conversion Efficiencies 78 Efficiencies of Mechanical and Electrical Devices 82 2–8 Energy and Environment 85 Ozone and Smog 86 Acid Rain 87 The Greenhouse Effect: Global Warming and Climate Change 88 Topic of Special Interest: Mechanisms of Heat Transfer 91 Summary 96 References and Suggested Readings 97 Problems 97 Contents cen98179_fm_i-xxvi.indd ix 11/29/13 6:39 PM
THERMODYNAMICS CHAPTER THREE 4-2 Energy Balance for Closed Systems 169 PROPERTIES OF PURE SUBSTANCES 111 4-3 Specific Heats 174 4-4 Internal Energy,Enthalpy,and Specific Heats 3-1 Pure Substance 112 of Ideal Gases 176 3-2 Phases of a Pure Substance 112 Specific Heat Relations of Ideal Gases 178 45 3-3 Phase-Change Processes Internal Energy,Enthalpy,and Specific Heats of of Pure Substances 113 Solids and Liquids 183 Internal Energy Changes 184 Compressed Liquid and Saturated Liquid 114 Enthalpy Changes 184 Saturated Vapor and Superheated Vapor 114 Saturation Temperature and Saturation Pressure 115 Topic of Special Interest:Thermodynamic Aspects of Some Consequences of Tsat and Pe Dependence 116 Biological Systems 187 3-4 Property Diagrams for Phase-Change Summary 195 References and Suggested Readings 195 Processes 118 Problems 196 1 The T-v Diagram 118 2 The P-v Diagram 120 Extending the Diagrams to Include the Solid Phase 120 3 The P-T Diagram 122 CHAPTER FIVE The P-v-TSurface 123 3-5 Property Tables 124 MASS AND ENERGY ANALYSIS OF CONTROL Enthalpy-A Combination Property 124 VOLUMES 213 1a Saturated Liquid and Saturated Vapor States 125 5-1 Conservation of Mass 214 1b Saturated Liquid-Vapor Mixture 127 Mass and Volume Flow Rates 214 2 Superheated Vapor 130 3 Compressed Liquid 131 Conservation of Mass Principle 216 Reference State and Reference Values 132 Mass Balance for Steady-Flow Processes 218 3-6 The Ideal-Gas Equation of State 134 Special Case:Incompressible Flow 219 Is Water Vapor an Ideal Gas?137 5-2 Flow Work and the Energy of a Flowing 3-7 Compressibility Factor-A Measure of Fluid 221 Deviation from Ideal-Gas Behavior 138 Total Energy of a Flowing Fluid 222 3-8 Energy Transport by Mass 223 Other Equations of State 141 van der Waals Equation of State 142 5-3 Energy Analysis of Steady-Flow Beattie-Bridgeman Equation of State 142 Systems 225 Benedict-Webb-Rubin Equation of State 143 5-4 Some Steady-Flow Engineering Virial Equation of State 144 Devices 228 Topic of Special Interest:Vapor Pressure and Phase 1 Nozzles and Diffusers 229 Equilibrium 146 2 Turbines and Compressors 232 Summary 150 3 Throttling Valves 234 References and Suggested Readings 151 4a Mixing Chambers 236 Problems 151 4b Heat Exchangers 238 5 Pipe and Duct Flow 240 5-5 Energy Analysis of Unsteady-Flow CHAPTER FOUR Processes 242 ENERGY ANALYSIS OF CLOSED SYSTEMS 163 Topic of Special Interest:General Energy Equation 247 Summary 251 4-1 Moving Boundary Work 164 References and Suggested Readings 252 Polytropic Process 168 Problems 252
x THERMODYNAMICS chapter three PROPERTIES OF PURE SUBSTANCES 111 3–1 Pure Substance 112 3–2 Phases of a Pure Substance 112 3–3 Phase-Change Processes of Pure Substances 113 Compressed Liquid and Saturated Liquid 114 Saturated Vapor and Superheated Vapor 114 Saturation Temperature and Saturation Pressure 115 Some Consequences of Tsat and Psat Dependence 116 3–4 Property Diagrams for Phase-Change Processes 118 1 The T-v Diagram 118 2 The P-v Diagram 120 Extending the Diagrams to Include the Solid Phase 120 3 The P-T Diagram 122 The P-v-T Surface 123 3–5 Property Tables 124 Enthalpy—A Combination Property 124 1a Saturated Liquid and Saturated Vapor States 125 1b Saturated Liquid–Vapor Mixture 127 2 Superheated Vapor 130 3 Compressed Liquid 131 Reference State and Reference Values 132 3–6 The Ideal-Gas Equation of State 134 Is Water Vapor an Ideal Gas? 137 3–7 Compressibility Factor—A Measure of Deviation from Ideal-Gas Behavior 138 3–8 Other Equations of State 141 van der Waals Equation of State 142 Beattie-Bridgeman Equation of State 142 Benedict-Webb-Rubin Equation of State 143 Virial Equation of State 144 Topic of Special Interest: Vapor Pressure and Phase Equilibrium 146 Summary 150 References and Suggested Readings 151 Problems 151 chapter four ENERGY ANALYSIS OF CLOSED SYSTEMS 163 4–1 Moving Boundary Work 164 Polytropic Process 168 4–2 Energy Balance for Closed Systems 169 4–3 Specific Heats 174 4–4 Internal Energy, Enthalpy, and Specific Heats of Ideal Gases 176 Specific Heat Relations of Ideal Gases 178 4–5 Internal Energy, Enthalpy, and Specific Heats of Solids and Liquids 183 Internal Energy Changes 184 Enthalpy Changes 184 Topic of Special Interest: Thermodynamic Aspects of Biological Systems 187 Summary 195 References and Suggested Readings 195 Problems 196 chapter five MASS AND ENERGY ANALYSIS OF CONTROL VOLUMES 213 5–1 Conservation of Mass 214 Mass and Volume Flow Rates 214 Conservation of Mass Principle 216 Mass Balance for Steady-Flow Processes 218 Special Case: Incompressible Flow 219 5–2 Flow Work and the Energy of a Flowing Fluid 221 Total Energy of a Flowing Fluid 222 Energy Transport by Mass 223 5–3 Energy Analysis of Steady-Flow Systems 225 5–4 Some Steady-Flow Engineering Devices 228 1 Nozzles and Diffusers 229 2 Turbines and Compressors 232 3 Throttling Valves 234 4a Mixing Chambers 236 4b Heat Exchangers 238 5 Pipe and Duct Flow 240 5–5 Energy Analysis of Unsteady-Flow Processes 242 Topic of Special Interest: General Energy Equation 247 Summary 251 References and Suggested Readings 252 Problems 252 cen98179_fm_i-xxvi.indd x 11/29/13 6:39 PM
xi CONTENTS CHAPTER SIX 7-4 Isentropic Processes 340 THE SECOND LAW OF THERMODYNAMICS 275 7-5 Property Diagrams Involving Entropy 342 7-6 What Is Entropy?343 6-1 Introduction to the Second Law 276 Entropy and Entropy Generation in Daily Life 346 6-2 Thermal Energy Reservoirs 277 7-7 The Tds Relations 347 6-3 Heat Engines 278 7-8 Entropy Change of Liquids and Solids 349 Thermal Efficiency 279 7-9 The Entropy Change of Ideal Gases 352 Can We Save Qou?281 Constant Specific Heats (Approximate Analysis)353 The Second Law of Thermodynamics: Variable Specific Heats (Exact Analysis)353 Kelvin-Planck Statement 283 Isentropic Processes of Ideal Gases 355 6-4 Refrigerators and Heat Pumps 283 Constant Specific Heats(Approximate Analysis)355 Coefficient of Performance 284 Variable Specific Heats(Exact Analysis)356 Heat Pumps 285 Relative Pressure and Relative Specific Volume 356 Performance of Refrigerators,Air-Conditioners, 7-10 Reversible Steady-Flow Work 359 and Heat Pumps 286 Proof that Steady-Flow Devices Deliver The Second Law of Thermodynamics: the Most and Consume the Least Work Clausius Statement 288 When the Process is Reversible 362 Equivalence of the Two Statements 289 6-5 Perpetual-Motion Machines 290 7-11 Minimizing the Compressor Work 363 Multistage Compression with Intercooling 364 6-6 Reversible and Irreversible Processes 292 7-12 Isentropic Efficiencies of Steady-Flow Irreversibilities 293 Internally and Externally Reversible Processes 294 Devices 367 6-7 The Carnot Cycle 295 Isentropic Efficiency of Turbines 367 Isentropic Efficiencies of Compressors and Pumps 369 The Reversed Carnot Cycle 297 Isentropic Efficiency of Nozzles 371 6-8 The Carnot Principles 297 7-13 Entropy Balance 373 6-9 The Thermodynamic Temperature Scale 299 Entropy Change of a System,ASsytem 374 Mechanisms of Entropy Transfer,Sin and Sout 374 6-10 The Carnot Heat Engine 301 1 Heat Transfer 374 The Quality of Energy 302 2 Mass Flow 375 Quantity versus Quality in Daily Life 303 Entropy Generation,Sgen 376 Closed Systems 377 6-11 The Carnot Refrigerator and Heat Pump 304 Control Volumes 378 Topic of Special Interest:Household Refrigerators 307 Entropy Generation Associated Summary 311 with a Heat Transfer Process 385 References and Suggested Readings 312 Topic of Special Interest:Reducing the Cost of Problems 312 Compressed Air 386 Summary 395 References and Suggested Readings 396 CHAPTER SEVEN Problems 397 ENTROPY 329 CHAPTER EIGHT 7-1 Entropy 330 EXERGY 421 A Special Case:Internally Reversible Isothermal Heat Transfer Processes 333 8-1 Exergy:Work Potential of Energy 422 7-2 The Increase of Entropy Principle 334 Exergy(Work Potential)Associated Some Remarks about Entropy 336 with Kinetic and Potential Energy 423 7-3 Entropy Change of Pure Substances 337 8-2 Reversible Work and Irreversibility 425
CONTENTS xi chapter six THE SECOND LAW OF THERMODYNAMICS 275 6–1 Introduction to the Second Law 276 6–2 Thermal Energy Reservoirs 277 6–3 Heat Engines 278 Thermal Efficiency 279 Can We Save Qout? 281 The Second Law of Thermodynamics: Kelvin–Planck Statement 283 6–4 Refrigerators and Heat Pumps 283 Coefficient of Performance 284 Heat Pumps 285 Performance of Refrigerators, Air-Conditioners, and Heat Pumps 286 The Second Law of Thermodynamics: Clausius Statement 288 Equivalence of the Two Statements 289 6–5 Perpetual-Motion Machines 290 6–6 Reversible and Irreversible Processes 292 Irreversibilities 293 Internally and Externally Reversible Processes 294 6–7 The Carnot Cycle 295 The Reversed Carnot Cycle 297 6–8 The Carnot Principles 297 6–9 The Thermodynamic Temperature Scale 299 6–10 The Carnot Heat Engine 301 The Quality of Energy 302 Quantity versus Quality in Daily Life 303 6–11 The Carnot Refrigerator and Heat Pump 304 Topic of Special Interest: Household Refrigerators 307 Summary 311 References and Suggested Readings 312 Problems 312 chapter seven ENTROPY 329 7–1 Entropy 330 A Special Case: Internally Reversible Isothermal Heat Transfer Processes 333 7–2 The Increase of Entropy Principle 334 Some Remarks about Entropy 336 7–3 Entropy Change of Pure Substances 337 7–4 Isentropic Processes 340 7–5 Property Diagrams Involving Entropy 342 7–6 What Is Entropy? 343 Entropy and Entropy Generation in Daily Life 346 7–7 The T ds Relations 347 7–8 Entropy Change of Liquids and Solids 349 7–9 The Entropy Change of Ideal Gases 352 Constant Specific Heats (Approximate Analysis) 353 Variable Specific Heats (Exact Analysis) 353 Isentropic Processes of Ideal Gases 355 Constant Specific Heats (Approximate Analysis) 355 Variable Specific Heats (Exact Analysis) 356 Relative Pressure and Relative Specific Volume 356 7–10 Reversible Steady-Flow Work 359 Proof that Steady-Flow Devices Deliver the Most and Consume the Least Work When the Process is Reversible 362 7–11 Minimizing the Compressor Work 363 Multistage Compression with Intercooling 364 7–12 Isentropic Efficiencies of Steady-Flow Devices 367 Isentropic Efficiency of Turbines 367 Isentropic Efficiencies of Compressors and Pumps 369 Isentropic Efficiency of Nozzles 371 7–13 Entropy Balance 373 Entropy Change of a System, DSsystem 374 Mechanisms of Entropy Transfer, Sin and Sout 374 1 Heat Transfer 374 2 Mass Flow 375 Entropy Generation, Sgen 376 Closed Systems 377 Control Volumes 378 Entropy Generation Associated with a Heat Transfer Process 385 Topic of Special Interest: Reducing the Cost of Compressed Air 386 Summary 395 References and Suggested Readings 396 Problems 397 chapter eight EXERGY 421 8–1 Exergy: Work Potential of Energy 422 Exergy (Work Potential) Associated with Kinetic and Potential Energy 423 8–2 Reversible Work and Irreversibility 425 cen98179_fm_i-xxvi.indd xi 11/29/13 6:39 PM
xii THERMODYNAMICS 8-3 Second-Law Efficiency 430 9-9 The Brayton Cycle with Regeneration 513 8-4 Exergy Change of a System 433 9-10 The Brayton Cycle with Intercooling,Reheating, Exergy of a Fixed Mass:Nonflow (or Closed System) and Regeneration 516 Exergy 433 Exergy of a Flow Stream:Flow (or Stream) 9-11 Ideal Jet-Propulsion Cycles 520 Exergy 436 Modifications to Turbojet Engines 524 8-5 Exergy Transfer by Heat,Work, 9-12 Second-Law Analysis of Gas Power And Mass 438 Cycles 526 Exergy by Heat Transfer,Q 439 Topic of Special Interest:Saving Fuel and Money by Driving Exergy Transfer by Work,W 440 Sensibly 530 Exergy Transfer by Mass,m 440 Summary 536 8-6 The Decrease of Exergy Principle and Exergy References and Suggested Readings 538 Problems 538 Destruction 441 Exergy Destruction 442 8-7 Exergy Balance:Closed Systems 443 CHAPTER TEN 8-8 Exergy Balance:Control Volumes 454 Exergy Balance for Steady-Flow Systems 455 VAPOR AND COMBINED POWER CYCLES 553 Reversible Work 456 Second-Law Efficiency of Steady-Flow 10-1 The Carnot Vapor Cycle 554 Devices 456 Topic of Special Interest:Second-Law 10-2 Rankine Cycle:The Ideal Cycle for Vapor Power Aspects of Daily Life 463 Cycles 555 Summary 467 Energy Analysis of the ldeal Rankine Cycle 555 References and Suggested Readings 468 Problems 468 10-3 Deviation of Actual Vapor Power Cycles from Idealized Ones 558 10-4 How Can We Increase the Efficiency of the CHAPTER NINE Rankine Cycle?561 Lowering the Condenser Pressure GAS POWER CYCLES 485 (Lowers T）561 Superheating the Steam to High Temperatures (Increases Thighave)562 9-1 Basic Considerations in the Analysis of Power Increasing the Boiler Pressure Cycles 486 (Increases Thghave)562 9-2 The Carnot Cycle and its Value in 10-5 The Ideal Reheat Rankine Cycle 565 Engineering 488 10-6 The Ideal Regenerative Rankine 9-3 Air-Standard Assumptions 490 Cycle 569 9-4 An Overview of Reciprocating Engines 490 Open Feedwater Heaters 569 Closed Feedwater Heaters 571 9-5 Otto Cycle:The Ideal Cycle for Spark-Ignition Engines 492 10-7 Second-Law Analysis of Vapor Power Cycles 577 9-6 Diesel Cycle:The Ideal Cycle for Compression-Ignition Engines 499 10-8 Cogeneration 579 9-7 Stirling and Ericsson Cycles 502 10-9 Combined Gas-Vapor Power Cycles 584 9-8 Brayton Cycle:The Ideal Cycle for Topic of Special Interest:Binary Vapor Gas-Turbine Engines 506 Cycles 587 Development of Gas Turbines 509 Summary 589 Deviation of Actual Gas-Turbine Cycles References and Suggested Readings 590 from Idealized Ones 512 Problems 590
xii THERMODYNAMICS 8–3 Second-Law Efficiency 430 8–4 Exergy Change of a System 433 Exergy of a Fixed Mass: Nonflow (or Closed System) Exergy 433 Exergy of a Flow Stream: Flow (or Stream) Exergy 436 8–5 Exergy Transfer by Heat, Work, And Mass 438 Exergy by Heat Transfer, Q 439 Exergy Transfer by Work, W 440 Exergy Transfer by Mass, m 440 8–6 The Decrease of Exergy Principle and Exergy Destruction 441 Exergy Destruction 442 8–7 Exergy Balance: Closed Systems 443 8–8 Exergy Balance: Control Volumes 454 Exergy Balance for Steady-Flow Systems 455 Reversible Work 456 Second-Law Efficiency of Steady-Flow Devices 456 Topic of Special Interest: Second-Law Aspects of Daily Life 463 Summary 467 References and Suggested Readings 468 Problems 468 chapter nine GAS POWER CYCLES 485 9–1 Basic Considerations in the Analysis of Power Cycles 486 9–2 The Carnot Cycle and its Value in Engineering 488 9–3 Air-Standard Assumptions 490 9–4 An Overview of Reciprocating Engines 490 9–5 Otto Cycle: The Ideal Cycle for Spark-Ignition Engines 492 9–6 Diesel Cycle: The Ideal Cycle for Compression-Ignition Engines 499 9–7 Stirling and Ericsson Cycles 502 9–8 Brayton Cycle: The Ideal Cycle for Gas-Turbine Engines 506 Development of Gas Turbines 509 Deviation of Actual Gas-Turbine Cycles from Idealized Ones 512 9–9 The Brayton Cycle with Regeneration 513 9–10 The Brayton Cycle with Intercooling, Reheating, and Regeneration 516 9–11 Ideal Jet-Propulsion Cycles 520 Modifications to Turbojet Engines 524 9–12 Second-Law Analysis of Gas Power Cycles 526 Topic of Special Interest: Saving Fuel and Money by Driving Sensibly 530 Summary 536 References and Suggested Readings 538 Problems 538 chapter ten VAPOR AND COMBINED POWER CYCLES 553 10–1 The Carnot Vapor Cycle 554 10–2 Rankine Cycle: The Ideal Cycle for Vapor Power Cycles 555 Energy Analysis of the Ideal Rankine Cycle 555 10–3 Deviation of Actual Vapor Power Cycles from Idealized Ones 558 10–4 How Can We Increase the Efficiency of the Rankine Cycle? 561 Lowering the Condenser Pressure (Lowers Tlow,avg) 561 Superheating the Steam to High Temperatures (Increases Thigh,avg) 562 Increasing the Boiler Pressure (Increases Thigh,avg) 562 10–5 The Ideal Reheat Rankine Cycle 565 10–6 The Ideal Regenerative Rankine Cycle 569 Open Feedwater Heaters 569 Closed Feedwater Heaters 571 10–7 Second-Law Analysis of Vapor Power Cycles 577 10–8 Cogeneration 579 10–9 Combined Gas–Vapor Power Cycles 584 Topic of Special Interest: Binary Vapor Cycles 587 Summary 589 References and Suggested Readings 590 Problems 590 cen98179_fm_i-xxvi.indd xii 11/29/13 6:39 PM