Handbook of Thermal Engineering Kreith

\u201cFrontMatter.\u201d The CRC Handbook of Thermal Engineering. Ed. Frank Kreith Boca Raton: CRC Press LLC, 2000 Library of Congress Cataloging-in-Publication Data The CRC handbook of thermal engineering / edited by Frank Kreith. p. cm. -- (The mechanical engineering handbook series) Includes bibliographical references and index. ISBN 0-8493-9581-X (alk. paper) 1. Heat engineering Handbooks, manuals, etc. I. Kreith, Frank. II. Series. TJ260.C69 1999 621.402\u2014dc21 99-38340 CIP This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. A wide variety of references are listed. Reasonable ef forts have been made to publish reliable data and information, but the author and the publisher cannot assume responsibility for the v alidity of all materials or for the consequences of their use. Neither this book nor any part may be reproduced or transmitted in any form or by an y means, electronic or mechanical, including photocopying, micro\ufb01lming, and recording, or by any information storage or retrie val system, without prior permission in writing from the publisher . All rights reserved. Authorization to photocopy items for internal or personal use, or the personal or internal use of speci\ufb01c clients, may be granted by CRC Press LLC, provided that $.50 per page photocopied is paid directly to Copyright Clearance Center , 222 Rosewood Drive, Danvers, MA 01923 USA. The fee code for users of the Transactional Reporting Service is ISBN 0-8493-9581-X/00/$0.00+$.50. The fee is subject to change without notice. F or organizations that hav e been granted a photocopy license by the CCC, a separate system of payment has been arranged. The consent of CRC Press LLC does not extend to copying for general distrib ution, for promotion, for creating new works, or for resale. Speci\ufb01c permission must be obtained in writing from CRC Press LLC for such copying. Direct all inquiries to CRC Press LLC, 2000 Corporate Blvd., N.W ., Boca Raton, Florida 33431. T rademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identi\ufb01cation and explanation, without intent to infringe. © 2000 by CRC Press LLC No claim to original U.S. Government w orks International Standard Book Number 0-8493-9581-X Library of Congress Card Number 99-38340 Printed in the United States of America 1 2 3 4 5 6 7 8 9 0 Printed on acid-free paper Acknowledgment This book is dedicated to pr ofessionals in the \ufb01eld of thermal engineer ing. I want to expr ess my appreciation for the assistanc e rendered by members of the Editorial A dvisor y Board, as well as the lead authors of the var ious sections. I would also like t o acknowledge the assistance of the man y reviewers who provided constructiv e criticism on var ious parts of this handbook during its development. Their reviews were in the form of w ritten comments as w ell as telephone calls and e-mails. I cannot remember all the people who assist ed as reviewers, and rather than mention a few and lea ve out others, I am thanking them as a group . There ar e, of course, some special individuals w ithout whose dedication and assistance this book w ould not have been possible. The y include m y editorial assistant, Bev W eiler , and the editors at CR C \u2014 N orm Stanton, Bob St ern, and M agg ie M ogck. M y w ife, Marion, helped keep track of the \ufb01les and assisted with other important facets of this handbook. But the exist ence of the handbook and its high quality is clearly the work of the individual authors, and I want to expr ess my deep appreciation to eac h and ever y one of them for their contribution. I hope that the handbook will ser v e as a useful referenc e on all topics of inter est to thermal engineers in their professional liv es. B ut during the planning stages of the book, certain choices had to be made to limit its scope. I realize, however , that the \ufb01eld of thermal eng ineering is ever -changing and growing. I would, therefore, like to in v ite engineers who will use this book to give me their input on t opics that should be included in the next edition. I would also like to in vite readers and users of the handbook to send me any c orrections, er ro rs, or omissions they disco ver , in order that these can be c orrected in the next printing. Frank Kr eith Boulder , Colorado fkreith@aol.c om © 2000 by CRC Press LLC Introduction Industrial resear ch today is c onducted in a changing, hectic, and highly competitiv e global environment. U ntil about 25 years ago , the R&D c onducted in the U .S. and the technologies based upon it wer e internationally dominant. But in the last 20 y ears, stro ng g lobal co mpetition has emerged and the pace at which high technology products are intr oduced has increased. Consequently , the lif etime of a new technology has shortened and the economic bene\ufb01ts of being \ufb01rst in the marketplace hav e forced an emphasis on short-term goals for industrial de v elopment. T o be suc cessful in the international market- place, corporations must hav e access to the lat est developments and most recent e xper imental data as rapidly as possible. In addition to the incr eased pace of industrial R&D , man y American companies ha ve manufacturing facilities, as well as product development acti vities in other countries. F ur thermore, the restructuring of many c ompanies has led to an ex cessiv e burden of debt and to curtailment of in-house industrial research. All of these develo pments make it imperative for industry to hav e access to the lat est information in a con venient form as rapidly as possible. The goal of this handbook is to pro v ide this type of up-to-date information for engineers invol ved in the \ufb01eld of thermal engineering . This handbook is not designed to co mpete with tr aditional handbooks of heat tr ansfer that stress fundamental principles, analy tical approac hes to thermal problems, and elegant solutions of traditional problems in the thermal scienc es. The goal of this handbook is to provide information on speci\ufb01c topics of current inter est in a con venient form that is accessible t o the average engineer in industry . The handbook contains in the \ufb01rst thr ee chapters suf\ufb01cient background information t o refresh the reader's memor y of the basic principles necessar y to understand speci\ufb01c applications. The bulk of the book, howev er , is dev oted to applications in thermal design and analysis for technologies of cur rent int erest, as well as to c omputer solutions of heat tr ansfer and thermal engineering problems. The applications treat ed in the book have been select ed on the basis of their current relevance t o the development of new products in diverse \ufb01elds suc h as food processing, energ y conservation, bioengi- neering, desalination, measurement techniq ues in \ufb02uid \ufb02ow and heat transfer , and other speci\ufb01c topics. Each application section stands on its o w n, but referenc e is made to the basic introductory material as necessary . The introductory material is presented in such a manner that it can be r eferred to and used by several authors of application sections. F or the con venience of the reader , each author has been requested t o use the same nomenclature in or der to help the reader in the transition from material in some of the basic chapt ers to the application chapters. But wherev er necessar y , authors ha ve de\ufb01ned special symbols in their chapters. A special feature of this handbook is an introduction to the use of the Second Law rather than the First Law of Thermodynamics in analysis, optimization, and ec onomics. This appr oach has been widely used in Eur ope and A sia for many years, but has not yet penetrated engineering education and usage in the U .S. The Second Law appr oach will be found par ticularly helpful in analyzing and o ptimizing thermal systems for the generation and/or conservation of energy . © 2000 by CRC Press LLC The material for this handbook has been peer reviewed and carefully pr oofread. H owev er , in a project of this magnitude with authors from vary ing backgrounds and differ ent countries, it is una voidable that errors and/or omissions occur . As the edit or , I w ould, ther efore, lik e to in v ite the pr ofessional engineers who use this book to giv e me their feedback on topics that should be included in the next edition. I would also greatly appr eciate it if an y readers who \ufb01nd an error would c ontact me by e-mail in order for the manuscript to be c or rect ed in the next printing. Since CR C Press expects to updat e the book frequently , both in hard copy and o n CD-ROM, errors will be corrected and to pics of interest will be added promptly . Frank Kr eith fkreith@aol.c om Boulder , CO © 2000 by CRC Press LLC Nomenclature Symbol Quantity U nit Dimensions (MLtT) SI English a V elocit y of sound m/s ft/s L t \u20131 a Ac celeration m/s 2 ft/s 2 L t \u20132 A Area: A c , cr oss-sectional area; m 2 ft 2 L 2 A p , pr ojected area of a body normal to the direction of \ufb02ow; A q , ar ea through which rate of heat \ufb02ow is q; A g , surfac e area; A o , outside surfac e area; A i , inside surfac e area; A f , \ufb01n surfac e area b Breadth or width m ft L c Speci\ufb01c heat; c p , speci\ufb01c heat at c onstant pressure; c v , speci\ufb01c heat at c onstant volume J/kg K Btu/lb m °R L 2 t \u20132 T \u20131 C Constant or Coef\ufb01cient; C D , t otal drag coef\ufb01cient; C f , skin friction c oef\ufb01cient; C fx , local value of C f at distance x, from leading edge; \u2014 C f , a verage value of C f none none \u2014 C Thermal capacity J/K Btu/°F M L 2 t \u20132 T \u20131 · C Hourly heat capacity rate; · C c , hourly heat capacity rate of colder \ufb02uid in a heat exc hanger ; · C h , hourly heat capacity of hotter \ufb02uid; C*, ratio of heat capacity rates in heat exc hangers W/K Btu/hr°F M L 2 t \u20131 T \u20131 D Diameter , D H , h ydraulic diameter; D o , outside diameter; D i , inside diamet er mf t L e Base of natural or Napierian logarithm none none \u2014 e T otal energy per unit mass J/kg Btu/lb m L 2 t \u20132 \u2014 E T otal energ y J Btu M L 2 t \u20132 E Emissive po wer of a r adiating body; E b , emissi ve power of a blackbody W/m 2 Btu/hr·ft 2 M t \u20132 E \u03bb Monoc hromatic emissive po wer per micron at wav elength \u03bb W/m µm Btu/hr·ft 2 micron M t \u20132 L \u20131 f Darcy friction factor for \ufb02ow thr ough a pipe or duct none none \u2014 f \u2032 Friction coef\ufb01cient for \ufb02ow o ver banks of tubes none none \u2014 FF o r c e ; F B , buo yant force N lb M L t \u20132 F T T emperature factor none none \u2014 F 1-2 Geometric shape factor for radiation from one blackbody to another none none \u2014 g A cceleration due to gravity m/s 2 ft/s 2 L t \u20132 g c Dimensional con version factor 1.0 kg·m/N·s 2 32.2 ft·lb m /lb·s 2 G Mass velocity or \ufb02ow rate per unit area kg/s·m 2 lb m /hr·ft 2 M L \u20132 t \u20131 G Irr adiation incident on unit surface in unit time W/m 2 Btu/hr·ft 2 M L \u20132 t \u20131 h Enthalpy per unit mass J/kg Btu/lb m L 2 t \u20132 © 2000 by CRC Press LLC Symbol Quantity U nit Dimensions (MLtT) SI English h Local heat transfer coef\ufb01cient; \u2013 h, a verage heat transfer coef\ufb01cient \u2013 h = \u2013 h c + \u2013 h r ; h b , heat transfer coef\ufb01cient of a boiling liquid; h c , local con vection heat transfer coef\ufb01cient; \u2013 h c , a verage heat transfer coef\ufb01cient; \u2013 h r , a verage heat transfer coef\ufb01cient for radiation W/m 2 ·K Btu/hr·ft 2 ·°F M t \u20133 T \u20131 h fg Latent heat of condensation or evaporation J/kg Btu/lb m L 2 t \u20132 H Head, elevation of hy draulic g rade line m ft L i Ang le between sun direction and surfac e normal rad deg \u2014 I Moment of inertia m 4 ft 4 L 4 I Intensity of r adiation W/sr Btu/hr unit solid angle M L 2 t \u20133 I \u03bb Intensity per unit wav elength W/sr·µm Btu/hr·sr micron M L t \u20133 J Radiosity W/m 2 Btu/hr·ft 2 M L \u20132 t \u20131 k Ther mal co nductivit y; k s , thermal c onductivit y of a solid; k f , thermal c onductivit y of a \ufb02uid; k g , thermal conductivity of a gas W/m·K Btu/hr·ft°F M L \u20132 t \u20131 T \u20131 K Thermal conductance; k k , thermal c onductance for conduction heat transfer; k c , thermal con vection conductanc e; K r , thermal conduction for radiation heat transfer W/K Btu/hr·ft°F M t \u20131 T \u20131 K Bulk modulus of elasticity P a lb/ft 2 M L \u20131 t \u20132 log Logarithm to the base 10 none none \u2014 ln Logarithm to the base e none none \u2014 l Length, general or characteristic length of a body m ft L L Lift N lb M L t \u20132 L f Latent heat of solidi\ufb01cation J/kg Btu/lb m L 2 t \u20132 · m Mass \ufb02ow rat e kg/s lb m /s M t \u20131 m Mass kg lb m M M Molecular weight gm/gm mole lb m /lb mole \u2014 · M Momentum per unit time N lb MLt \u20132 n Manning roughness factor none none \u2014 n Number of moles none none \u2014 NPSH Net positi ve suction head m ft L N Number in general; number of tubes, etc. none none \u2014 p Static pressure; p c , critical pressur e; p A , partial pressure of component A N/m 2 psi or lb/ft 2 o r at m M L \u20131 t \u20132 P W etted perimeter or height of weir m ft L q Discharge per unit width m 2 /s ft 2 /s L 2 t \u20131 q Rate of heat \ufb02ow ; q k , rate of heat \ufb02ow by conduction; q r , rate of heat \ufb02ow by radiation; q c , rate of heat \ufb02ow by con vection; q b , rate of heat \ufb02ow by n ucleate boiling W Btu/hr M L 2 t \u20133 q \ue002 Rate of heat genera tion per unit v olume W/m 3 Btu/hr·ft 3 M L \u20131 t \u20133 q \u2033 Rate of heat generation per unit area (heat \ufb02ux) W/m 2 Btu/hr·ft 2 M t \u20133 Q Quantit y of heat J Btu M L 2 t \u20133 r Radius; r H , h ydraulic radius; r i , inner radius; r o , outer radius mf t L R Ther mal resistanc e; R c , thermal r esistance to con vection heat transfer; R k , thermal r esistance to conduction heat transfer; R f , t o radiation heat transfer K/W hr°F/Btu L T M \u20131 © 2000 by CRC Press LLC Symbol Quantity U nit Dimensions (MLtT) SI English R e Electrical resistance ohm ohm \u2014 R P erfect gas constant 8.314 J/K·kg mole 1545 ft·lb f /lb·mole°F L 2 t \u20132 T \u20131 s Entropy per unit mass J/kg·K ft·lb/lb m ·°R L 2 t \u20132 T \u20131 S Entropy J/K ft·lb/°R ML 2 t \u20132 T \u20131 S L Distance between ce nterlines of tubes in adjacent longitudinal rows mf t L S T Distance between ce nterlines of tubes in adjacent transverse rows mf t L t Time s hr or s t TT e m p e r a t u r e ; T b , t emperature of bulk of \ufb02uid; T f , mean \ufb01lm temperature; T s , surfac e temperature, T o , t emperature of \ufb02uid far remo ved from heat source or sink; T m , mean bulk t emperature of \ufb02uid \ufb02owing in a duct; T M , t emperature of saturated vapor; T sl , t emperature of a saturated liquid; T fr , fr eezing temperature; T t , liquid temperature; T as , adiabatic wall t emperature K or °C °F or R T u Internal energy per unit mass J/kg Btu/lb m L 2 t \u20132 u V elocity in x direction; u \u2032 , instantaneous \ufb02uctuating x component of velocity ; \u2013 u, a verage velocity m/s ft/s or ft/hr L t \u20131 u* Shear stress velocity m/s ft/s Lt \u20131 U Internal energy J Btu ML 2 t \u20132 U Overall heat transfer coef\ufb01cient W/m 2 K Btu/hr·ft 2 °F M t \u20133 T \u20131 U \u221e Free-str eam velocity m/s ft/s L t \u20131 v Speci\ufb01c v olume m 3 /kg ft 3 /lb m L 3 M \u20131 v V elocity in y direction; v \u2032 , instantaneous \ufb02uctuating y component of velocity m/s ft/s or ft/hr L t \u20131 V V olume m 3 ft 3 L 3 · V V olumet ric \ufb02ow rate m 3 /s ft 3 /s L 3 t \u20131 W s Shaft work m·N ft·lb ML 2 t \u20132 · W Rate of work output or power W Btu/hr M L 2 t \u20133 x Coordinate or distanc e from the leading edge; x c , critical distance from the leading edge where \ufb02ow becomes turbulent mf t L x Quality percent perc ent none y Coordinate or distance from a solid boundary measured in direction normal to surfac e mf t L z Coordinate m ft L Z Ratio of hourly heat capacity rates in heat exc hangers none none \u2014 Greek S ymbols \u03b1 Absorptivity for radiation, \u03b1 \u03bb , monochromatic absorptivity at wavelength \u03bb none none \u2014 \u03b1 Thermal diffusivity = k/ \u03c1 cm 2 /s ft 2 /s L 2 t \u20131 \u03b2 T emperature coef\ufb01cient of volume e xpansion 1/K 1/R T \u20131 \u03b2 k T emperature coef\ufb01cient of thermal conducti v ity 1/K 1/R T \u20131 \u03b3 Speci\ufb01c heat ratio, c p /c v none none \u2014 \u0393 Circulation m 2 ft 2 L 2 t \u20131 © 2000 by CRC Press LLC Symbol Quantity U nit Dimensions (MLtT) SI English \u0393 Body force per unit mass N/kg lb/lb m L t \u20132 \u0393 c Mass rate of \ufb02ow of condensate per unit breadth = · m/ \u03c0 D for a vertical tube kg/s·m lb m /hr·ft M L \u20132 t \u20131 \u03b4 Boundary-layer thickness; \u03b4 h , hydr odynamic boundary-layer thickness; \u03b4 th , thermal boundary-layer thickness mf t L \u2206 Difference between values none none \u2014 \u03b5 Heat ex changer effectiveness none none \u2014 \ue003 Roughness height m ft L \ue003 Emissivity for radiation; \ue003 \u03bb , monochromatic emissivity at wavelength \u03bb ; \ue003 \u03c6 , emissivity in direction \u03c6 \ue003 H Thermal eddy diffusivity m 2 /s ft 2 /s L 2 t \u20131 \ue003 M Momentum edd y diffusivit y m 2 /s ft 2 /s L 2 t \u20131 \u03b6 Ratio of ther mal to h ydrodynamic boundary- layer thickness, \u03b4 h / \u03b4 th \u2014\u2014 \u2014 \u03b7 Ef\ufb01ciency; \u03b7 f , \ufb01n ef\ufb01ciency none none \u2014 \u03bb W av elength; \u03bb max , wav elength at which monochromatic emissi ve power E b \u03bb is a maximum µm micron L µ Absolute viscosity N·s/m 2 lb/ft·s M L \u20131 t \u20131 \u03bd Kinematic viscosity , µ/ \u03c1 m 2 /s ft 2 /s L 2 t \u20131 \u03bd f Frequency of radiation 1/s 1/s t \u20131 \u03a6 V elocit y potential m 2 /s ft 2 /s L 2 t \u20131 \u03c1 Mass density , 1/v; \u03c1 1 , density of liquid; \u03c1 v , density of vap or kg/m 3 lb m ft 3 M L \u20133 \u03c4 Shearing stress, \u03c4 s , shearing stress at surface; \u03c4 w , shear at wall of a tube or a duct N/m 2 lb/ft 2 M L \u20131 t \u20132 \u03c4 T ransmissivity for ra diation none none \u2014 \u03c3 Stefan-Boltzmann constant W/m 2 K 4 Btu/hr ft 2 R 4 M t \u20133 T \u20134 \u03c3 Surface t ension N/m lb/ft M t \u20132 \u03c6 Angl e rad r a d \u2014 \u03c8 Stokes \u2019 stream function m 3 /s ft 3 /s L 3 t \u20131 \u03c9 Angular velocity 1/s 1/s t \u20131 \u03c9 Solid angle sr steradian \u2014 Dimensionless Numbers Bi Biot number Ec Eckert number Eu E uler number Fo Fourier modulus Fr Froude number Gz Graetz number Gr Grahsof number Ja Jako b nu mb er Kn Knudsen number M Mach number Nu A verage Nusselt number; N u D , a verage diameter Nusselt n umber ; N u x , local N usselt number Pe Pe cl e t n um b e r © 2000 by CRC Press LLC Pr P randtl number Ra Rayleigh number Re R eynolds number ; R e x , local value of Re at a distance x from leading edge; Re D , diamet er Reynolds number; R e b , bubble R eynolds number \u0398 Boundary Fourier modulus or dimensionless time St Stanton n umber W e W eber number Miscellaneous a > b a great than b a a smaller than b \u221d Proportional sign \ue002 Appro ximately equal sign \u221e In\ufb01nity sign \u03a3 Summation sign Subscripts c = critical condition i = inlet f= \ufb01 n u = unit quantities w = wall or properties at wall temperature c.s. = control surfac e c.v . = control v olume o = stag nation or standard stat e condition; outlet or outside 1,2 = inlet and outlet, r espectively , of control volume Not e: Those sy mbols and subscripts that are not included in the abov e list are de\ufb01ned in the text.

Handbook of Thermal Engineering Kreith

Termodinâmica

UNIP

Termodinâmica

Continue navegando

Materiais relacionados

Perguntas relacionadas

What is the purpose of the text? a. To describe the potential of Montería, Colombia for the development of thermal districts. b. To explain the m...

What is the main role of the understanding of heat and thermodynamics in Electrical Engineering? A) To understand the history of the concept of hea...

What is the purpose of the article? The purpose of the article is to analyze an alternative for cooling companies in Montería, Colombia, using a t...

Outros materiais