Thermodynamics An Engineering Approach 8th Ed《热动力学工程方法学》英文版（整本书籍）

THERMODYNAMICSAN ENGINEERING APPROACHEIGHTH EDITIONcen98179_fm_i-xxvi.indd i 11/29/13 639 PMThis page intentionally left blankTHERMODYNAMICSAN ENGINEERING APPROACHEIGHTH EDITIONYUNUS A. ÇENGELUniversity of Nevada, RenoMICHAEL A. BOLESNorth Carolina State Universitycen98179_fm_i-xxvi.indd iii 11/29/13 639 PMTHERMODYNAMICS AN ENGINEERING APPROACH, EIGHTH EDITIONPublished 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 or by any means, or stored in a database or retri 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 4ISBN 978-0-07-339817-4MHID 0-07-339817-9Senior Vice President, Products some serve as page summaries.cen98179_fm_i-xxvi.indd xix 11/29/13 639 PMxxTHERMODYNAMICSLEARNING OBJECTIVES AND SUMMARIESEach chapter begins with an overview of the material to be covered and chapter-specific learning objectives. A summary is included at the end of each chapter, providing a quick review of basic concepts and important rela-tions, and pointing out the relevance of the material.NUMEROUS WORKED-OUT EXAMPLES WITH A SYSTEMATIC SOLUTIONS PROCEDUREEach chapter contains several worked-out examples that clarify the material and illustrate the use of the basic principles. An intuitive and systematic approach is used in the solution of the example problems, while maintaining an inal conversational style. The problem is first stated, and the objectives are identified. The assumptions are then stated, together with their justifications. The proper-ties needed to solve the problem are listed separately if appropriate. Numerical values are used together with their units to emphasize that numbers without units are meaningless, and that unit manipulations are as important as manipulating the numerical values with a calculator. The significance of the findings is dis-cussed following the solutions. This approach is also used consistently in the solutions presented in the instructor’s solutions manual.A WEALTH OF REAL-WORLD END-OF-CHAPTER PROBLEMSThe end-of-chapter problems are grouped under specific topics to make prob-lem selection easier for both instructors and students. Within each group of problems are Concept Questions, indicated by “C,” to check the students’ level of understanding of basic concepts. The problems under Review Prob-lems are more comprehensive in nature and are not directly tied to any specific section of a chapterin some cases they require review of material learned in previous chapters. Problems designated as Design and Essay are intended to encourage students to make engineering judgments, to conduct indepen-dent exploration of topics of interest, and to communicate their findings in a professional manner. Problems designated by an “E” are in English units, and SI users can ignore them. Problems with the are solved using EES, and complete solutions together with parametric studies are included on the textbook’s website. Problems with the are comprehensive in nature and are intended to be solved with a computer, possibly using the EES software. Several economics- and safety-related problems are incorporated throughout to promote cost and safety awareness among engineering students. Answers to selected problems are listed immediately following the problem for conve-nience to students. In addition, to prepare students for the Fundamentals of Engineering Exam that is becoming more important for the outcome-based ABET 2000 criteria and to facilitate multiple-choice tests, over 200 multiple-choice problems are included in the end-of-chapter problem sets. They are placed under the title Fundamentals of Engineering FE Exam Problems for easy recognition. These problems are intended to check the understanding of fundamentals and to help readers avoid common pitfalls.RELAXED SIGN CONVENTIONThe use of a al sign convention for heat and work is abandoned as it often becomes counterproductive. A physically meaningful and engag-ing approach is adopted for interactions instead of a mechanical approach. cen98179_fm_i-xxvi.indd xx 11/29/13 639 PMxxiPREFACESubscripts “in” and “out,” rather than the plus and minus signs, are used to indicate the directions of interactions.PHYSICALLY MEANINGFUL ULASThe physically meaningful s of the balance equations rather than u-las are used to foster deeper understanding and to avoid a cookbook approach. The mass, energy, entropy, and rgy balances for any system undergoing any process are expressed asMass balance min2 mout5 Dmsystem Energy balance Ein2 Eout5 DEsystem Net energy transfer Change in internal, kinetic,by heat, work, and mass potential, etc., energiesEntropy balance Sin2 Sout1 Sgen5 DSsystemNet entropy transfer Entropy Changeby heat and mass generation in entropyrgy balance Xin2 Xout2 Xdestroyed5 DXsystemNet rgy transfer rgy Changeby heat, work, and mass destruction in rgyThese relations reinforce the fundamental principles that during an actual process mass and energy are conserved, entropy is generated, and rgy is destroyed. Students are encouraged to use these s of balances in early chapters after they specify the system, and to simplify them for the particular problem. A more relaxed approach is used in later chapters as students gain mastery.A CHOICE OF SI ALONE OR SI/ENGLISH UNITSIn recognition of the fact that English units are still widely used in some industries, both SI and English units are used in this text, with an emphasis on SI. The material in this text can be covered using combined SI/English units or SI units alone, depending on the preference of the instructor. The property tables and charts in the appendices are presented in both units, except the ones that involve dimensionless quantities. Problems, tables, and charts in English units are designated by “E” after the number for easy recognition, and they can be ignored by SI users.TOPICS OF SPECIAL INTERESTMost chapters contain a section called “Topic of Special Interest” where interesting aspects of thermodynamics are discussed. Examples include Ther-modynamic Aspects of Biological Systems in Chapter 4, Household Refrigera-tors in Chapter 6, Second-Law Aspects of Daily Life in Chapter 8, and Saving Fuel and Money by Driving Sensibly in Chapter 9. The topics selected for these sections provide intriguing extensions to thermodynamics, but they can be ignored if desired without a loss in continuity.cen98179_fm_i-xxvi.indd xxi 11/29/13 639 PMxxiiTHERMODYNAMICSGLOSSARY OF THERMODYNAMIC TERMSThroughout the chapters, when an important key term or concept is intro-duced and defined, it appears in boldface type. Fundamental thermo dynamic terms and concepts also appear in a glossary located on our accompanying website www.mhhe.com/cengel. This unique glossary helps to reinforce key terminology and is an excellent learning and review tool for students as they move forward in their study of thermodynamics. In addition, students can test their knowledge of these fundamental terms by using the flash cards and other interactive resources.CONVERSION FACTORSFrequently used conversion factors and physical constants are listed on the inner cover pages of the text for easy reference.SUPPLEMENTSThe following supplements are available to users of the book.ENGINEERING EQUATION SOLVER EESDeveloped by Sanford Klein and William Beckman from the University of WisconsinMadison, this software combines equation-solving capability and engineering property data. EES can do optimization, parametric analysis, and linear and nonlinear regression, and provides publication-quality plot-ting capabilities. Thermodynamics and transport properties for air, water, and many other fluids are built in, and EES allows the user to enter property data or functional relationships.EES is a powerful equation solver with built-in functions and property tables for thermodynamic and transport properties as well as automatic unit checking capability. It requires less time than a calculator for data entry and allows more time for thinking critically about modeling and solving engineer-ing problems. Look for the EES icons in the homework problems sections of the text.The Limited Academic Version of EES is available for departmental license upon adoption of the Eighth Edition of Thermodynamics An Engineering Approach meaning that the text is required for students in the course. You may load this software onto your institution’s computer system, for use by students and faculty related to the course, as long as the arrangement between McGraw-Hill Education and F-Chart is in effect. There are minimum order requirements stipulated by F-Chart to qualify.PROPERTIES TABLE BOOKLETISBN 0-07-762477-7This booklet provides students with an easy reference to the most important property tables and charts, many of which are found at the back of the text-book in both the SI and English units.COSMOSMcGraw-Hill’s COSMOS Complete Online Solutions Manual Organization System allows instructors to streamline the creation of assignments, quizzes, and tests by using problems and solutions from the textbook, as well as their own custom material. COSMOS is now available online at http//cosmos.mhhe.com/cen98179_fm_i-xxvi.indd xxii 11/29/13 639 PMxxiiiPREFACEACKNOWLEDGMENTSThe authors would like to acknowledge with appreciation the numerous and valuable comments, suggestions, constructive criticisms, and praise from the following uators and reviewersEdward AndersonTexas Tech UniversityJohn BiddleCal Poly Pomona UniversityGianfranco DiGiuseppeKettering UniversityShoeleh Di JulioCalifornia State University-NorthridgeAfshin GhajarOklahoma State UniversityHarry HardeeNew Mexico State UniversityKevin LyonsNorth Carolina State UniversityKevin MacfarlanJohn Brown UniversitySaeed ManafzadehUniversity of Illinois-ChicagoAlex MoutsoglouSouth Dakota State UniversityRishi RajThe City College of New YorkMaria SanchezCalifornia State University-FresnoKalyan SrinivasanMississippi State UniversityRobert StigerGonzaga UniversityTheir suggestions have greatly helped to improve the quality of this text. In particular we would like to express our gratitude to Mehmet Kanoglu of the University of Gaziantep, Turkey, for his valuable contributions, his critical review of the manuscript, and for his special attention to accuracy and detail.We also would like to thank our students, who provided plenty of feedback from students’ perspectives. Finally, we would like to express our apprecia-tion to our wives, Zehra Çengel and Sylvia Boles, and to our children for their continued patience, understanding, and support throughout the preparation of this text.Yunus A. ÇengelMichael A. Bolescen98179_fm_i-xxvi.indd xxiii 11/29/13 639 PMThis page intentionally left blankMCGRAW-HILL CONNECT®ENGINEERINGMcGraw-Hill Connect Engineering is a web-based assignment and assessment plat that gives students the means to better connect with their course-work, with their instructors, and with the important concepts that they will need to know for success now and in the future. With Connect Engineering, instructors can deliver assignments, quizzes, and tests easily online. Students can practice important skills at their own pace and on their own schedule.Connect Engineering for Thermodynamics An Engineering Approach, Eighth Edition is available via the text website at www.mhhe.com/cengelCOSMOSMcGraw-Hill’s COSMOS Complete Online Solutions Manual Organization System allows instructors to streamline the creation of assignments, quiz-zes, and tests by using problems and solutions from the textbook, as well as their own custom material. COSMOS is now available online at http//cosmos.mhhe.com/WWW.MHHE.COM/CENGELThis site offers resources for students and instructors.The following resources are available for students Glossary of Key Terms in ThermodynamicsBolded terms in the text are defined in this accessible glossary. Organized at the chapter level or available as one large file. Student Study GuideThis resource outlines the fundamental concepts of the text and is a helpful guide that allows students to focus on the most important concepts. The guide can also serve as a lecture outline for instructors. Learning ObjectivesThe chapter learning objectives are outlined here. Organized by chapter and tied to ABET objectives. Self-QuizzingStudents can test their knowledge using multiple-choice quizzing. These self-tests provide immediate feedback and are an excellent learning tool. FlashcardsInteractive flashcards test student understanding of the text terms and their definitions. The program also allows students to flag terms that require further understanding. Crossword PuzzlesAn interactive, timed puzzle that provides hints as well as a notes section. ErrataIf errors should be found in the text, they will be reported here. Online Resources for Students and Instructorscen98179_fm_i-xxvi.indd xxv 11/29/13 639 PMxxviTHERMODYNAMICSThe following resources are available for instructors under password protection Instructor TestbankAdditional problems prepared for instructors to assign to students. Solutions are given, and use of EES is recommended to verify accuracy. Correlation GuideNew users of this text will appreciate this resource. The guide provides a smooth transition for instructors not currently using the Çengel/Boles text. Image LibraryThe electronic version of the figures are supplied for easy integration into course presentations, exams, and assignments. Instructor’s GuideProvides instructors with helpful tools such as sample syllabi and exams, an ABET conversion guide, a thermodynamics glossary, and chapter objectives. ErrataIf errors should be found in the solutions manual, they will be reported here. Solutions ManualThe detailed solutions to all text homework problems are provided in PDF . EES Solutions ManualThe entire solutions manual is also available in EES. Any problem in the text can be modified and the solution of the modified problem can readily be obtained by copying and pasting the given EES solution on a blank EES screen and hitting the solve button. PP slidesPowerpoint presentation slides for all chapters in the text are available for use in lectures AppendicesThese are provided in PDF for ease of use.cen98179_fm_i-xxvi.indd xxvi 11/29/13 639 PM1INTRODUCTION AND BASIC CONCEPTSEvery science has a unique vocabulary associated with it, and thermo-dynamics is no exception. Precise definition of basic concepts s a sound foundation for the development of a science and prevents possible misunderstandings. We start this chapter with an overview of ther-modynamics and the unit systems, and continue with a discussion of some basic concepts such as system, state, state postulate, equilibrium, and pro-cess. We discuss intensive and extensive properties of a system and define density, specific gravity, and specific weight. We also discuss temperature and temperature scales with particular emphasis on the International Tem-perature Scale of 1990. We then present pressure, which is the normal force rted by a fluid per unit area and discuss absolute and gage pressures, the variation of pressure with depth, and pressure measurement devices, such as manometers and barometers. Careful study of these concepts is essential for a good understanding of the topics in the following chapters. Finally, we present an intuitive systematic problem-solving technique that can be used as a model in solving engineering problems.1OBJECTIVESThe objectives of Chapter 1 are to■ Identify the unique vocabulary associated with thermodynamics through the precise definition of basic concepts to a sound foundation for the development of the principles of thermody-namics.■ Review the metric SI and the English unit systems that will be used throughout the text.■ Explain the basic concepts of thermodynamics such as system, state, state postulate, equilibrium, process, and cycle.■ Discuss properties of a system and define density, specific gravity, and specific weight.■ Review concepts of temperature, temperature scales, pressure, and absolute and gage pressure.■ Introduce an intuitive systematic problem-solving technique.CHAPTERcen98179_ch01_001-050.indd 1 11/28/13 314 PM2INTRODUCTION AND BASIC CONCEPTS1–1 ■THERMODYNAMICS AND ENERGYThermodynamics can be defined as the science of energy. Although every-body has a feeling of what energy is, it is difficult to give a precise defini-tion for it. Energy can be viewed as the ability to cause changes.The name thermodynamics stems from the Greek words therme heat and dynamis power, which is most descriptive of the early efforts to convert heat into power. Today the same name is broadly interpreted to include all aspects of energy and energy transations including power generation, refrigeration, and relationships among the properties of matter.One of the most fundamental laws of nature is the conservation of energy principle. It simply states that during an interaction, energy can change from one to another but the total amount of energy remains constant. That is, energy cannot be created or destroyed. A rock falling off a cliff, for example, picks up speed as a result of its potential energy being converted to kinetic energy Fig. 1–1. The conservation of energy principle also s the back-bone of the diet industry A person who has a greater energy food than energy output rcise will gain weight store energy in the of fat, and a person who has a smaller energy than output will lose weight Fig. 1–2. The change in the energy content of a body or any other system is equal to the difference between the energy and the energy output, and the energy balance is expressed as Ein2 Eout5 DE.The first law of thermodynamics is simply an expression of the con-servation of energy principle, and it asserts that energy is a thermodynamic property. The second law of thermodynamics asserts that energy has quality as well as quantity, and actual processes occur in the direction of decreasing quality of energy. For example, a cup of hot coffee left on a table eventually cools, but a cup of cool coffee in the same room never gets hot by itself Fig. 1–3. The high-temperature energy of the coffee is degraded transed into a less useful at a lower temperature once it is trans-ferred to the surrounding air.Although the principles of thermodynamics have been in existence since the creation of the universe, thermodynamics did not emerge as a science until the construction of the first successful atmospheric steam engines in England by Thomas Savery in 1697 and Thomas Newcomen in 1712. These engines were very slow and inefficient, but they opened the way for the development of a new science.The first and second laws of thermodynamics emerged simultaneously in the 1850s, primarily out of the works of William Rankine, Rudolph Clausius, and Lord Kelvin erly William Thomson. The term thermodynamics was first used in a publication by Lord Kelvin in 1849. The first thermody-namics textbook was written in 1859 by William Rankine, a professor at the University of Glasgow.It is well-known that a substance consists of a large number of particles called molecules. The properties of the substance naturally depend on the behavior of these particles. For example, the pres