Heat exchangers : selection, rating, and thermal design

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HEAT

EXCHANGERS

Selection, Rating, and

Thermal Design

Third Edition HEAT

EXCHANGERS

Selection, Rating, and Thermal Design

HEAT EXCHANGERS Kakaç • Liu • Pramuanjaroenkij

www.crcpress.com

Third

Edition

Third Edition

MECHANICAL ENGINEERING

Heat exchangers are essential in a wide range of engineering applications, including

power plants, automobiles, airplanes, process and chemical industries, and heating,

air conditioning and refrigeration systems. Revised and updated with new problem

sets and examples, Heat Exchangers: Selection, Rating, and Thermal Design, Third

Edition presents a systematic treatment of the various types of heat exchangers,

focusing on selection, thermal-hydraulic design, and rating.

Topics discussed include

• Classification of heat exchangers according to different criteria

• Basic design methods for sizing and rating of heat exchangers

• Single-phase forced convection correlations in channels

• Pressure drop and pumping power for heat exchangers and their

piping circuit

• Design solutions for heat exchangers subject to fouling

• Double-pipe heat exchanger design methods

• Correlations for the design of two-phase flow heat exchangers

• Thermal design methods and processes for shell-and-tube, compact,

and gasketed-plate heat exchangers

• Thermal design of condensers and evaporators

This third edition contains two new chapters. Micro/Nano Heat Transfer explores

the thermal design fundamentals for microscale heat exchangers and the

enhancement heat transfer for applications to heat exchanger design with

nanofluids. It also examines single-phase forced convection correlations as well

as flow friction factors for microchannel flows for heat transfer and pumping

power calculations. Polymer Heat Exchangers introduces an alternative design

option for applications hindered by the operating limitations of metallic

heat exchangers. The appendices provide the thermophysical properties of

various fluids.

Each chapter contains examples illustrating thermal design methods and procedures

and relevant nomenclature. End-of-chapter problems enable students to test their

assimilation of the material.

HEAT

EXCHANGERS

Selection, Rating, and

Thermal Design

Third Edition

This page intentionally left blank

HEAT

EXCHANGERS

Selection, Rating, and

Thermal Design

Third Edition

CRC Press is an imprint of the

Taylor & Francis Group, an informa business

Boca Raton London New York

CRC Press

Taylor & Francis Group

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© 2012 by Taylor & Francis Group, LLC

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Version Date: 20120110

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v

Contents

Preface................................................................................................................... xiii

1. Classification of Heat Exchangers...............................................................1

1.1 Introduction ...........................................................................................1

1.2 Recuperation and Regeneration..........................................................1

1.3 Transfer Processes.................................................................................6

1.4 Geometry of Construction...................................................................8

1.4.1 Tubular Heat Exchangers........................................................8

1.4.1.1 Double-Pipe Heat Exchangers................................8

1.4.1.2 Shell-and-Tube Heat Exchangers............................9

1.4.1.3 Spiral-Tube-Type Heat Exchangers ...................... 12

1.4.2 Plate Heat Exchangers...........................................................12

1.4.2.1 Gasketed Plate Heat Exchangers.......................... 12

1.4.2.2 Spiral Plate Heat Exchangers................................ 14

1.4.2.3 Lamella Heat Exchangers...................................... 15

1.4.3 Extended Surface Heat Exchangers..................................... 17

1.4.3.1 Plate-Fin Heat Exchanger...................................... 17

1.4.3.2 Tubular-Fin Heat Exchangers............................... 18

1.5 Heat Transfer Mechanisms................................................................23

1.6 Flow Arrangements ............................................................................ 24

1.7 Applications .........................................................................................25

1.8 Selection of Heat Exchangers ............................................................26

References .......................................................................................................30

2. Basic Design Methods of Heat Exchangers.............................................33

2.1 Introduction .........................................................................................33

2.2 Arrangement of Flow Paths in Heat Exchangers ...........................33

2.3 Basic Equations in Design..................................................................35

2.4 Overall Heat Transfer Coefficient..................................................... 37

2.5 LMTD Method for Heat Exchanger Analysis .................................43

2.5.1 Parallel- and Counterflow Heat Exchangers......................43

2.5.2 Multipass and Crossflow Heat Exchangers .......................47

2.6 The ε-NTU Method for Heat Exchanger Analysis .........................56

2.7 Heat Exchanger Design Calculation ................................................66

2.8 Variable Overall Heat Transfer Coefficient ..................................... 67

2.9 Heat Exchanger Design Methodology............................................. 70

Nomenclature.................................................................................................73

References .......................................................................................................78

vi Contents

3. Forced Convection Correlations for the Single-Phase Side of

Heat Exchangers............................................................................................ 81

3.1 Introduction ......................................................................................... 81

3.2 Laminar Forced Convection..............................................................84

3.2.1 Hydrodynamically Developed and Thermally

Developing Laminar Flow in Smooth Circular Ducts.......... 84

3.2.2 Simultaneously Developing Laminar Flow in

Smooth Ducts .........................................................................85

3.2.3 Laminar Flow through Concentric Annular

Smooth Ducts .........................................................................86

3.3 Effect of Variable Physical Properties ..............................................88

3.3.1 Laminar Flow of Liquids ......................................................90

3.3.2 Laminar Flow of Gases .........................................................92

3.4 Turbulent Forced Convection............................................................93

3.5 Turbulent Flow in Smooth Straight Noncircular Ducts ................99

3.6 Effect of Variable Physical Properties in Turbulent

Forced Convection ............................................................................ 103

3.6.1 Turbulent Liquid Flow in Ducts ........................................ 103

3.6.2 Turbulent Gas Flow in Ducts ............................................. 104

3.7 Summary of Forced Convection in Straight Ducts ...................... 107

3.8 Heat Transfer from Smooth-Tube Bundles .................................... 111

3.9 Heat Transfer in Helical Coils and Spirals .................................... 114

3.9.1 Nusselt Numbers of Helical Coils—Laminar Flow........ 116

3.9.2 Nusselt Numbers for Spiral Coils—Laminar Flow ........ 117

3.9.3 Nusselt Numbers for Helical Coils—Turbulent Flow..........117

3.10 Heat Transfer in Bends..................................................................... 118

3.10.1 Heat Transfer in 90° Bends ................................................. 118

3.10.2 Heat Transfer in 180° Bends ............................................... 119

Nomenclature............................................................................................... 120

References .....................................................................................................125

4. Heat Exchanger Pressure Drop and Pumping Power.......................... 129

4.1 Introduction ....................................................................................... 129

4.2 Tube-Side Pressure Drop ................................................................. 129

4.2.1 Circular Cross-Sectional Tubes.......................................... 129

4.2.2 Noncircular Cross-Sectional Ducts................................... 132

4.3 Pressure Drop in Tube Bundles in Crossflow............................... 135

4.4 Pressure Drop in Helical and Spiral Coils .................................... 137

4.4.1 Helical Coils—Laminar Flow ............................................ 138

4.4.2 Spiral Coils—Laminar Flow .............................................. 138

4.4.3 Helical Coils—Turbulent Flow........................................... 139

4.4.4 Spiral Coils—Turbulent Flow............................................. 139

4.5 Pressure Drop in Bends and Fittings ............................................. 140

4.5.1 Pressure Drop in Bends ...................................................... 140

4.5.2 Pressure Drop in Fittings.................................................... 142

Contents vii

4.6 Pressure Drop for Abrupt Contraction, Expansion, and

Momentum Change.......................................................................... 147

4.7 Heat Transfer and Pumping Power Relationship......................... 148

Nomenclature............................................................................................... 150

References ..................................................................................................... 155

5. Micro/Nano Heat Transfer........................................................................ 157

5.1 PART A—Heat Transfer for Gaseous and Liquid Flow in

Microchannels ................................................................................... 157

5.1.1 Introduction of Heat Transfer in Microchannels ............ 157

5.1.2 Fundamentals of Gaseous Flow in Microchannels ........ 158

5.1.2.1 Knudsen Number................................................. 158

5.1.2.2 Velocity Slip........................................................... 160

5.1.2.3 Temperature Jump ............................................... 160

5.1.2.4 Brinkman Number............................................... 161

5.1.3 Engineering Applications for Gas Flow ........................... 163

5.1.3.1 Heat Transfer in Gas Flow .................................. 165

5.1.3.2 Friction Factor....................................................... 169

5.1.3.3 Laminar to Turbulent Transition Regime......... 173

5.1.4 Engineering Applications of Single-Phase Liquid

Flow in Microchannels ....................................................... 177

5.1.4.1 Nusselt Number and Friction Factor

Correlations for Single-Phase Liquid Flow ...... 179

5.1.4.2 Roughness Effect on Friction Factor.................. 185

5.2 PART B—Single-Phase Convective Heat Transfer with

Nanofluids.......................................................................................... 186

5.2.1 Introduction of Convective Heat Transfer with

Nanofluids ............................................................................ 186

5.2.1.1 Particle Materials and Base Fluids..................... 187

5.2.1.2 Particle Size and Shape........................................ 187

5.2.1.3 Nanofluid Preparation Methods ........................ 188

5.2.2 Thermal Conductivity of Nanofluids ............................... 188

5.2.2.1 Classical Models ................................................... 189

5.2.2.2 Brownian Motion of Nanoparticles................... 191

5.2.2.3 Clustering of Nanoparticles................................ 193

5.2.2.4 Liquid Layering around Nanoparticles ............ 196

5.2.3 Thermal Conductivity Experimental Studies of

Nanofluids ............................................................................203

5.2.4 Convective Heat Trasfer of Nanofluids............................. 207

5.2.5 Analysis of Convective Heat Transfer of Nanofluids ..... 212

5.2.5.1 Constant Wall Heat Flux Boundary Condition... 212

5.2.5.2 Constant Wall Temperature Boundary

Condition............................................................... 214

5.2.6 Experimental Correlations of Convective Heat

Transfer of Nanofluids ........................................................ 216

viii Contents

Nomenclature............................................................................................... 224

References .....................................................................................................228

6. Fouling of Heat Exchangers...................................................................... 237

6.1 Introduction ....................................................................................... 237

6.2 Basic Considerations......................................................................... 237

6.3 Effects of Fouling .............................................................................. 239

6.3.1 Effect of Fouling on Heat Transfer.................................... 240

6.3.2 Effect of Fouling on Pressure Drop................................... 241

6.3.3 Cost of Fouling..................................................................... 243

6.4 Aspects of Fouling ............................................................................244

6.4.1 Categories of Fouling ..........................................................244

6.4.1.1 Particulate Fouling...............................................244

6.4.1.2 Crystallization Fouling........................................ 245

6.4.1.3 Corrosion Fouling ................................................ 245

6.4.1.4 Biofouling .............................................................. 245

6.4.1.5 Chemical Reaction Fouling................................. 246

6.4.2 Fundamental Processes of Fouling ................................... 246

6.4.2.1 Initiation ................................................................ 246

6.4.2.2 Transport ............................................................... 246

6.4.2.3 Attachment............................................................ 247

6.4.2.4 Removal ................................................................. 247

6.4.2.5 Aging...................................................................... 248

6.4.3 Prediction of Fouling........................................................... 248

6.5 Design of Heat Exchangers Subject to Fouling.............................250

6.5.1 Fouling Resistance...............................................................250

6.5.2 Cleanliness Factor................................................................256

6.5.3 Percent over Surface ............................................................ 257

6.5.3.1 Cleanliness Factor................................................260

6.5.3.2 Percent over Surface.............................................260

6.6 Operations of Heat Exchangers Subject to Fouling ..................... 262

6.7 Techniques to Control Fouling........................................................264

6.7.1 Surface Cleaning Techniques.............................................264

6.7.1.1 Continuous Cleaning...........................................264

6.7.1.2 Periodic Cleaning.................................................264

6.7.2 Additives ...............................................................................265

6.7.2.1 Crystallization Fouling........................................265

6.7.2.2 Particulate Fouling...............................................266

6.7.2.3 Biological Fouling.................................................266

6.7.2.4 Corrosion Fouling ................................................266

Nomenclature...............................................................................................266

References ..................................................................................................... 270

7. Double-Pipe Heat Exchangers ................................................................. 273

7.1 Introduction ....................................................................................... 273

Contents ix

7.2 Thermal and Hydraulic Design of Inner Tube ............................. 276

7.3 Thermal and Hydraulic Analysis of Annulus .............................. 278

7.3.1 Hairpin Heat Exchanger with Bare Inner Tube .............. 278

7.3.2 Hairpin Heat Exchangers with Multitube Finned

Inner Tubes ...........................................................................283

7.4 Parallel–Series Arrangements of Hairpins ................................... 291

7.5 Total Pressure Drop.......................................................................... 294

7.6 Design and Operational Features................................................... 295

Nomenclature............................................................................................... 297

References .....................................................................................................304

8. Design Correlations for Condensers and Evaporators .......................307

8.1 Introduction .......................................................................................307

8.2 Condensation.....................................................................................307

8.3 Film Condensation on a Single Horizontal Tube .........................308

8.3.1 Laminar Film Condensation..............................................308

8.3.2 Forced Convection ...............................................................309

8.4 Film Condensation in Tube Bundles .............................................. 312

8.4.1 Effect of Condensate Inundation....................................... 313

8.4.2 Effect of Vapor Shear........................................................... 317

8.4.3 Combined Effects of Inundation and Vapor Shear......... 317

8.5 Condensation inside Tubes..............................................................322

8.5.1 Condensation inside Horizontal Tubes ............................ 322

8.5.2 Condensation inside Vertical Tubes.................................. 327

8.6 Flow Boiling....................................................................................... 329

8.6.1 Subcooled Boiling ................................................................ 329

8.6.2 Flow Pattern.......................................................................... 331

8.6.3 Flow Boiling Correlations...................................................334

Nomenclature...............................................................................................353

References .....................................................................................................356

9. Shell-and-Tube Heat Exchangers............................................................. 361

9.1 Introduction ....................................................................................... 361

9.2 Basic Components............................................................................. 361

9.2.1 Shell Types ............................................................................ 361

9.2.2 Tube Bundle Types...............................................................364

9.2.3 Tubes and Tube Passes ........................................................366

9.2.4 Tube Layout ..........................................................................368

9.2.5 Baffle Type and Geometry.................................................. 371

9.2.6 Allocation of Streams .......................................................... 376

9.3 Basic Design Procedure of a Heat Exchanger............................... 378

9.3.1 Preliminary Estimation of Unit Size.................................380

9.3.2 Rating of the Preliminary Design .....................................386

9.4 Shell-Side Heat Transfer and Pressure Drop ................................ 387

9.4.1 Shell-Side Heat Transfer Coefficient.................................. 387

x Contents

9.4.2 Shell-Side Pressure Drop ....................................................389

9.4.3 Tube-Side Pressure Drop ....................................................390

9.4.4 Bell–Delaware Method........................................................ 395

9.4.4.1 Shell-Side Heat Transfer Coefficient.................. 396

9.4.4.2 Shell-Side Pressure Drop ....................................407

Nomenclature............................................................................................... 419

References .....................................................................................................425

10. Compact Heat Exchangers ........................................................................427

10.1 Introduction .....................................................................................427

10.1.1 Heat Transfer Enhancement...........................................427

10.1.2 Plate-Fin Heat Exchangers.............................................. 431

10.1.3 Tube-Fin Heat Exchangers.............................................. 431

10.2 Heat Transfer and Pressure Drop.................................................433

10.2.1 Heat Transfer....................................................................433

10.2.2 Pressure Drop for Finned-Tube Exchangers ................441

10.2.3 Pressure Drop for Plate-Fin Exchangers ......................441

Nomenclature...............................................................................................446

References .....................................................................................................449

11. Gasketed-Plate Heat Exchangers............................................................. 451

11.1 Introduction ..................................................................................... 451

11.2 Mechanical Features....................................................................... 451

11.2.1 Plate Pack and the Frame................................................453

11.2.2 Plate Types ........................................................................455

11.3 Operational Characteristics........................................................... 457

11.3.1 Main Advantages............................................................. 457

11.3.2 Performance Limits .........................................................459

11.4 Passes and Flow Arrangements....................................................460

11.5 Applications ..................................................................................... 461

11.5.1 Corrosion........................................................................... 462

11.5.2 Maintenance .....................................................................465

11.6 Heat Transfer and Pressure Drop Calculations..........................466

11.6.1 Heat Transfer Area ..........................................................466

11.6.2 Mean Flow Channel Gap................................................ 467

11.6.3 Channel Hydraulic Diameter.........................................468

11.6.4 Heat Transfer Coefficient................................................468

11.6.5 Channel Pressure Drop................................................... 474

11.6.6 Port Pressure Drop .......................................................... 474

11.6.7 Overall Heat Transfer Coefficient.................................. 475

11.6.8 Heat Transfer Surface Area ............................................ 475

11.6.9 Performance Analysis ..................................................... 476

11.7 Thermal Performance..................................................................... 481

Nomenclature...............................................................................................484

References .....................................................................................................488

Contents xi

12. Condensers and Evaporators.................................................................... 491

12.1 Introduction ..................................................................................... 491

12.2 Shell and Tube Condensers ........................................................... 492

12.2.1 Horizontal Shell-Side Condensers................................. 492

12.2.2 Vertical Shell-Side Condensers ...................................... 495

12.2.3 Vertical Tube-Side Condensers ...................................... 495

12.2.4 Horizontal in-Tube Condensers..................................... 497

12.3 Steam Turbine Exhaust Condensers.............................................500

12.4 Plate Condensers............................................................................. 501

12.5 Air-Cooled Condensers..................................................................502

12.6 Direct Contact Condensers............................................................503

12.7 Thermal Design of Shell-and-Tube Condensers .........................504

12.8 Design and Operational Considerations ..................................... 515

12.9 Condensers for Refrigeration and Air-Conditioning ................ 516

12.9.1 Water-Cooled Condensers.............................................. 518

12.9.2 Air-Cooled Condensers .................................................. 519

12.9.3 Evaporative Condensers ................................................. 519

12.10 Evaporators for Refrigeration and Air-Conditioning................ 522

12.10.1 Water-Cooling Evaporators (Chillers)........................... 522

12.10.2 Air-Cooling Evaporators (Air Coolers)......................... 523

12.11 Thermal Analysis............................................................................ 525

12.11.1 Shah Correlation .............................................................. 526

12.11.2 Kandlikar Correlation..................................................... 528

12.11.3 Güngör and Winterton Correlation............................... 529

12.12 Standards for Evaporators and Condensers................................ 531

Nomenclature...............................................................................................536

References .....................................................................................................540

13. Polymer Heat Exchangers .........................................................................543

13.1 Introduction ....................................................................................543

13.2 Polymer Matrix Composite Materials (PMC)..............................547

13.3 Nanocomposites .............................................................................. 551

13.4 Application of Polymers in Heat Exchangers ............................ 552

13.5 Polymer Compact Heat Exchangers .............................................563

13.6 Potential Applications for Polymer Film Compact

Heat Exchangers.............................................................................. 567

13.7 Thermal Design of Polymer Heat Exchangers............................ 570

References ..................................................................................................... 573

Appendix A.........................................................................................................577

Appendix B..........................................................................................................583

Index .....................................................................................................................607

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xiii

Preface

This third edition of Heat Exchangers: Selection, Rating, and Thermal Design has

retained the basic objectives and level of the second edition to present a sys￾tematic treatment of the selections, thermal–hydraulic designs, and ratings

of the various types of heat exchanging equipment. All the popular features

of the second edition are retained while new ones are added. In this edition,

modifications have been made throughout the book in response to users’

suggestions and input from students who heard lectures based on the sec￾ond edition of this book.

Included are 58 solved examples to demonstrate thermal–hydraulic

designs and ratings of heat exchangers; these examples have been exten￾sively revised in the third edition. A complete solutions manual is now also

available, which provides guidance for approaching the thermal design

problems of heat exchangers and for the design project topics suggested at

the end of each chapter.

Heat exchangers are vital in power producing plants, process and chemi￾cal industries, and in heating, ventilating, air-conditioning, refrigeration sys￾tems, and cooling of electronic systems. A large number of industries are

engaged in designing various types of heat exchange equipment. Courses

are offered at many colleges and universities on thermal design under vari￾ous titles.

There is extensive literature on this subject; however, the information

has been widely scattered. This book provides a systematic approach and

should be used as an up-to-date textbook based on scattered literature

for senior undergraduate and first-year graduate students in mechanical,

nuclear, aerospace, and chemical engineering programs who have taken

introductory courses in thermodynamics, heat transfer, and fluid mechan￾ics. This systematic approach is also essential for beginners who are inter￾ested in industrial applications of thermodynamics, heat transfer, and

fluid mechanics, and for the designers and the operators of heat exchange

equipment. This book focuses on the selections, thermohydraulic designs,

design processes, ratings, and operational problems of various types of heat

exchangers.

One of the main objectives of this textbook is to introduce thermal design

by describing various types of single- and two-phase flow heat exchangers,

detailing their specific fields of application, selection, and thermohydraulic

design and rating, and showing thermal design and rating processes with

worked examples and end-of-chapter problems including student design

projects.

xiv Preface

Much of this text is devoted to double-pipe, shell-and-tube, compact,

gasketed-plate heat exchanger types, condensers, and evaporators. Their

design processes are described and thermal–hydraulic design examples are

presented. Some other types, mainly specialized ones, are briefly described

without design examples. Thermal design factors and methods are common,

however, to all heat exchangers, regardless of their function.

This book begins in Chapter 1 with the classification of heat exchang￾ers according to different criteria. Chapter 2 provides the basic design

methods for sizing and rating heat exchangers. Chapter 3 is a review of

single-phase forced convection correlations in channels. A large number

of experimental and analytical correlations are available for the heat

transfer coefficient and flow friction factor for laminar and turbulent

flow through ducts. Thus, it is often a difficult and confusing task for

a student, and even a designer, to choose appropriate correlations. In

Chapter  3, recommended correlations for the single-phase side of heat

exchangers are given with worked examples. Chapter 4 discusses pres￾sure drop and pumping power for heat exchangers and their piping

circuit analysis. The thermal design fundamentals for microscale heat

exchangers and the enhancement heat transfer for the applications to

the heat exchanger design with nanofluids are provided in Chapter 5.

Also presented in Chapter 5 are single-phase forced convection correla￾tions and flow friction factors for microchannel flows for heat transfer

and pumping power calculations. One of the major unresolved problems

in heat exchanger equipment is fouling; the design of heat exchangers

subject to fouling is presented in Chapter 6. Double-pipe heat exchanger

design methods are presented in Chapter 7. The important design cor￾relations for the design of two-phase flow heat exchangers are given in

Chapter 8. The thermal design methods and processes for shell-and-tube,

compact, and gasketed-plate heat exchangers are presented in Chapters 9,

10, and 11 for single-phase duties, respectively. Chapter 10 deals with the

gasketed-plate heat exchangers, and has been revised with new correla￾tions to calculate heat transfer and friction coefficients for chevron-type

plates provided; solved examples in Chapter 10 and throughout the book

have been modified. With this arrangement, both advanced students and

beginners will achieve a better understanding of thermal design and will

be better prepared to specifically understand the thermal design of con￾densers and evaporators that is introduced in Chapter 12. An overview of

polymer heat exchangers is introduced in Chapter 13 as a new chapter; in

some applications, the operating limitations of metallic heat exchangers

have created the need to develop alternative designs using other materi￾als, such as polymers, which have the ability to resist fouling and corro￾sion. Besides, the use of polymers offers substantial reductions in weight,