Contents Preface Nomenclature 1 Classification of Heat Exchangers

1.1 Introduction 1.2 Classification According to Transfer Processes

1.2.1 Indirect-Contact Heat Exchangers 1.2.2 Direct-Contact Heat Exchangers Classification According to Number of Fluids Classification According to Surface Compactness 1.4.1 Gas-to-Fluid Exchangers 1.4.2 Liquid-to-Liquid and Phase-Change Exchangers Classification According to Construction Features 1.5.1 Tubular Heat Exchangers 1.5.2 Plate-Type Heat Exchangers 1.5.3 Extended Surface Heat Exchangers 1.5.4 Regenerators Classification According to Flow Arrangements 1.6.1 Single-Pass Exchangers 1.6.2 Multipass Exchangers Classification According to Heat Transfer Mechanisms Summary References Review Questions

1.3 1.4

1.5

1.6

1.7

2 Overview of Heat Exchanger Design Methodology 2.1 Heat Exchanger Design Methodology

2.1.1 Process and Design Specifications 2.1.2 Thermal and Hydraulic Design 2.1.3 Mechanical Design 2.1.4 2.1.5 Trade-off Factors 2.1.6 Optimum Design 2.1.7 Other Considerations

Manufacturing Considerations and Cost Estimates

xv xix

1 1 3 3 7 8 8

11 12 12 13 22 36 47 56 57 64 73 73 73 74 78 78 79 83 87 90 92 93 93

v i CONTENTS

2.2 Interactions Among Design Considerations Summary References Review Questions Problems

3 Basic Thermal Design Theory for Recuperators 3.1 3.2

Formal Analogy between Thermal and Electrical Entities Heat Exchanger Variables and Thermal Circuit 3.2.1 Assumptions for Heat Transfer Analysis 3.2.2 Problem Formulation 3.2.3 Basic Definitions 3.2.4 Thermal Circuit and U A

3.3 The E-NTU Method 3.3.1 Heat Exchanger Effectiveness E

3.3.2 3.3.3 Effectiveness - Number of Transfer Unit Relationships 3.4.1 Single-Pass Exchangers

3.5.1 Temperature Effectiveness P 3.5.2 Number of Transfer Units, NTU 3.5.3 Heat Capacity Rate Ratio R 3.5.4 General P-NTU Functional Relationship

3.6 P-NTU Relationships 3.6.1 Parallel Counterflow Exchanger, Shell Fluid Mixed, 1-2

TEMA E Shell 3.6.2 Multipass Exchangers The Mean Temperature Difference Method 3.7.1 Log-Mean Temperature Difference, LMTD 3.7.2 F Factors for Various Flow Arrangements 3.8.1 Counterflow Exchanger 3.8.2 Parallelflow Exchanger 3.8.3 Other Basic Flow Arrangements 3.8.4 Heat Exchanger Arrays and Multipassing Comparison of the E-NTU, P-NTU, and MTD Methods 3.9.1 3.9.2 The E-NTU Method 3.9.3 The P-NTU Method 3.9.4 The MTD Method

3.10 The $-P and PI - P 2 Methods 3.10.1 The +-P Method 3.10.2 The PI - P2 Method

Heat Capacity Rate Ratio C* Number of Transfer Units NTU

3.4

3.5 The P-NTU Method

3.7

Log-Mean Temperature Difference Correction Factor F 3.8

3.9 Solutions to the Sizing and Rating Problems

93 94 94 95 95 97 98

100 100 102 104 107 114 114 118 119 121 122 139 140 140 141 141 142

142 164 186 186 187 190 190 191 192 20 1 207 207 208 209 209 210 210 21 1

CONTENTS ni

3.1 1 Solution Methods for Determining Exchanger Effectiveness 3.1 1.1 Exact Analytical Methods 3.1 1.2 Approximate Methods 3.1 1.3 Numerical Methods 3.1 1.4 Matrix Formalism 3.1 1.5 Chain Rule Methodology 3.1 1.6 Flow-Reversal Symmetry 3.1 1.7 Rules for the Determination of Exchanger Effectiveness

with One Fluid Mixed 3.12 Heat Exchanger Design Problems

Summary References Review Questions Problems

4 Additional Considerations for Thermal Design of Recuperators 4.1 Longitudinal Wall Heat Conduction Effects

4.1.1 4.1.2 Single-Pass Counterflow Exchanger 4.1.3 Single-Pass Parallelflow Exchanger 4.1.4 Single-Pass Unmixed-Unmixed Crossflow Exchanger 4.1.5 Other Single-Pass Exchangers 4.1.6 Multipass Exchangers Nonuniform Overall Heat Transfer Coefficients 4.2.1 Temperature Effect 4.2.2 Length Effect 4.2.3 Combined Effect Additional Considerations for Extended Surface Exchangers 4.3.1 Thin Fin Analysis 4.3.2 Fin Efficiency 4.3.3 Fin Effectiveness 4.3.4 Extended Surface Efficiency Additional Considerations for Shell-and-Tube Exchangers 4.4.1 4.4.2 4.4.3 Finite Number of Baffles Summary References Review Questions Problems

Exchangers with C* = 0

4.2

4.3

4.4 Shell Fluid Bypassing and Leakage Unequal Heat Transfer Area in Individual Exchanger Passes

5 Thermal Design Theory for Regenerators 5.1 Heat Transfer Analysis

5.1.1 5.1.2 5.1.3 Governing Equations

Assumptions for Regenerator Heat Transfer Analysis Definitions and Description of Important Parameters

212 213 213 213 214 214 215

216 216 219 219 220 227 232 232 236 236 239 239 239 239 244 248 249 25 1 258 259 272 288 289 29 1 29 1 296 297 298 298 299 302 308 308 308 310 312

viii CONTENTS

5.2 The E-NTU, Method 5.2.1 Dimensionless Groups 5.2.2 5.2.3 Convection Conductance Ratio @A)* 5.2.4 5.2.5

Influence of Core Rotation and Valve Switching Frequency

c-NTU, Results for a Counterflow Regenerator E-NTU, Results for a Parallelflow Regenerator

5.3 The A-Il Method 5.3.1 Comparison of the E-NTU, and A-Il Methods 5.3.2 Solutions for a Counterflow Regenerator 5.3.3 Solution for a Parallelflow Regenerator

Influence of Longitudinal Wall Heat Conduction Influence of Transverse Wall Heat Conduction 5.5.1 Simplified Theory Influence of Pressure and Carryover Leakages 5.6.1

Influence of Matrix Material, Size, and Arrangement Summary References Review Questions Problems

5.4 5.5

5.6 Modeling of Pressure and Carryover Leakages for a Rotary Regenerator

5.7

6 Heat Exchanger Pressure Drop Analysis 6.1

6.2

6.3 6.4

6.5 6.6

6.1

Introduction 6.1.1 Importance of Pressure Drop 6.1.2 Fluid Pumping Devices 6.1.3 6.1.4 Extended Surface Heat Exchanger Pressure Drop 6.2.1 Plate-Fin Heat Exchangers 6.2.2 Tube-Fin Heat Exchangers Regenerator Pressure Drop Tubular Heat Exchanger Pressure Drop 6.4.1 Tube Banks 6.4.2 Shell-and-Tube Exchangers Plate Heat Exchanger Pressure Drop Pressure Drop Associated with Fluid Distribution Elements 6.6.1 Pipe Losses 6.6.2 6.6.3 Bend Losses Pressure Drop Presentation 6.7.1 6.7.2

Major Contributions to the Heat Exchanger Pressure Drop Assumptions for Pressure Drop Analysis

Sudden Expansion and Contraction Losses

Nondimensional Presentation of Pressure Drop Data Dimensional Presentation of Pressure Drop Data

316 316 320 320 32 1 326

337 34 1 344 345 348 355 355 360

360 366 37 1 372 373 376 378 378 318 380 380 38 1 381 382 391 392 393 393 393 397 399 399 399 403 412 413 414

CONTENTS

6.8 Pressure Drop Dependence on Geometry and Fluid Properties Summary References Review Questions Problems

7 Surface Basic Heat Transfer and Flow Friction Characteristics 7.1

7.2

7.3

7.4

7.5

7.6

7.7

7.8

Basic Concepts 7.1.1 Boundary Layers 7.1.2 Types of Flows 7.1.3 Free and Forced Convection 7.1.4 Basic Definitions Dimensionless Groups 7.2.1 Fluid Flow 7.2.2 Heat Transfer 7.2.3 Dimensionless Surface Characteristics as a Function of the

Reynolds Number Experimental Techniques for Determining Surface Characteristics 7.3.1 Steady-State Kays and London Technique 7.3.2 Wilson Plot Technique 7.3.3 Transient Test Techniques 7.3.4 Friction Factor Determination Analytical and Semiempirical Heat Transfer and Friction Factor Correlations for Simple Geometries 7.4.1 Fully Developed Flows 7.4.2 Hydrodynamically Developing Flows 7.4.3 Thermally Developing Flows 7.4.4 Simultaneously Developing Flows 7.4.5 Extended Reynolds Analogy 7.4.6 Limitations o f j vs. Re Plot Experimental Heat Transfer and Friction Factor Correlations for Complex Geometries 7.5.1 Tube Bundles 7.5.2 Plate Heat Exchanger Surfaces 7.5.3 Plate-Fin Extended Surfaces 7.5.4 Tube-Fin Extended Surfaces 7.5.5 Regenerator Surfaces Influence of Temperature-Dependent Fluid Properties 7.6.1

Influence of Superimposed Free Convection 7.7.1 Horizontal Circular Tubes 7.7.2 Vertical Circular Tubes Influence of Superimposed Radiation 7.8.1 Liquids as Participating Media

Correction Schemes for Temperature-Dependent Fluid Properties

ix

418 419 420 420 422 425 426 426 429 438 439 44 1 443 446

449 450 45 1 460 467 47 1

473 475 499 502 507 508 510

51 1 512 514 515 519 523 529

530 532 533 535 537 538

x CONTENTS

7.8.2 Gases as Participating Media Summary References Review Questions Problems

8 Heat Exchanger Surface Geometrical Characteristics 8.1 Tubular Heat Exchangers

8.1.1 Inline Arrangement 8.1.2 Staggered Arrangement

538 542 544 548 553 563 563 563 566

8.2 Tube-Fin Heat Exchangers 569 8.2.1 Circular Fins on Circular Tubes 569 8.2.2 Plain Flat Fins on Circular Tubes 572 8.2.3 General Geometric Relationships for Tube-Fin Exchangers 574

8.3 Plate-Fin Heat Exchangers 574 8.3.1 Offset Strip Fin Exchanger 5 74 8.3.2 Corrugated Louver Fin Exchanger 580 8.3.3 General Geometric Relationships for Plate-Fin Surfaces 584

8.4 Regenerators with Continuous Cylindrical Passages 8.4.1 Triangular Passage Regenerator Shell-and-Tube Exchangers with Segmental Baffles 8.5.1 Tube Count 8.5.2 8.5.3

Summary References Review Questions

8.5

Window and Crossflow Section Geometry Bypass and Leakage Flow Areas

8.6 Gasketed Plate Heat Exchangers

585 585 587 587 589 592 597 598 598 599

9 Heat Exchanger Design Procedures 60 1 9.1 Fluid Mean Temperatures

9.1.1 9.1.2 9.1.3 Multipass Heat Exchangers

9.2 Plate-Fin Heat Exchangers 9.2.1 Rating Problem 9.2.2 Sizing Problem

9.3 Tube-Fin Heat Exchangers 9.3.1 Surface Geometries 9.3.2 Heat Transfer Calculations 9.3.3 Pressure Drop Calculations 9.3.4 Core Mass Velocity Equation

9.4.1 Limiting Cases for the Design 9.4.2 Uniqueness of a PHE for Rating and Sizing

Heat Exchangers with C* = 0 Counterflow and Crossflow Heat Exchangers

9.4 Plate Heat Exchangers

60 1 603 604 604 605 605 617 63 1 63 1 63 1 632 632 632 633 635

C 0 N T E N T S

9.4.3 Rating a PHE 9.4.4 Sizing a PHE

9.5.1 9.5.2 Rating Procedure 9.5.3 Approximate Design Method 9.5.4

9.5 Shell-and-Tube Heat Exchangers Heat Transfer and Pressure Drop Calculations

More Rigorous Thermal Design Method 9.6 Heat Exchanger Optimization

Summary References Review Questions Problems

10 Selection of Heat Exchangers and Their Components 10.1 Selection Criteria Based on Operating Parameters

10.1.1 Operating Pressures and Temperatures 10.1.2 cost 10.1.3 Fouling and Cleanability 10.1.4 Fluid Leakage and Contamination 10.1.5 Fluids and Material Compatibility 10.1.6 Fluid Type

10.2 General Selection Guidelines for Major Exchanger Types 10.2.1 Shell-and-Tube Exchangers 10.2.2 Plate Heat Exchangers 10.2.3 Extended-Surface Exchangers 10.2.4 Regenerator Surfaces

10.3 Some Quantitative Considerations 10.3.1 Screening Methods 10.3.2 Performance Evaluation Criteria 10.3.3 Evaluation Criteria Based on the Second Law of

Thermodynamics 10.3.4 Selection Criterion Based on Cost Evaluation Summary References Review Questions Problems

11 Thermodynamic Modeling and Analysis 1 1.1 Introduction

1 1.1.1 Heat Exchanger as a Part of a System 1 1.1.2 Heat Exchanger as a Component

11.2 Modeling a Heat Exchanger Based on the First Law of Thermodynamics 1 1.2.1 Temperature Distributions in Counterflow and Parallelflow

Exchangers 1 1.2.2 True Meaning of the Heat Exchanger Effectiveness

xi

637 645 646 646 650 658 663 664 667 667 668 669 673 674 674 675 675 678 678 678 680 680 693 694 699 699 700 713

723 724 726 726 727 732 735 735 737 738

738

739 745

xii CONTENTS

1 1.2.3 Temperature Difference Distributions for Parallelflow and

1 1.2.4 Temperature Distributions in Crossflow Exchangers

11.3.1 Entropy Generation Caused by Finite Temperature Differences 11.3.2 Entropy Generation Associated with Fluid Mixing 11.3.3 Entropy Generation Caused by Fluid Friction

1 1.4 Thermodynamic Irreversibility and Temperature Cross Phenomena 1 1.4.1 Maximum Entropy Generation 1 1.4.2 External Temperature Cross and Fluid Mixing Analogy 11.4.3 Thermodynamic Analysis for 1-2 TEMA J Shell-and-Tube

11.5 A Heuristic Approach to an Assessment of Heat Exchanger Effectiveness

11.6 Energy, Exergy, and Cost Balances in the Analysis and Optimization of Heat Exchangers 1 1.6.1 Temperature-Enthalpy Rate Change Diagram 11.6.2 Analysis Based on an Energy Rate Balance 11.6.3 Analysis Based on Energy/Enthalpy and Cost Rate Balancing 1 1.6.4 Analysis Based on an Exergy Rate Balance 11.6.5 Thermodynamic Figure of Merit for Assessing Heat

Exchanger Performance 11.6.6 Accounting for the Costs of Exergy Losses in a Heat

Exchanger 11.7 Performance Evaluation Criteria Based on the Second Law of

Thermodynamics Summary References Review Questions Problems

Counterflow Exchangers

11.3 Irreversibilities in Heat Exchangers

Heat Exchanger

12 Flow Maldistribution and Header Design 12.1 Geometry-Induced Flow Maldistribution

12.1.1 Gross Flow Maldistribution 12.1.2 Passage-to-Passage Flow Maldistribution 12.1.3 Manifold-Induced Flow Maldistribution

12.2 Operating Condition-Induced Flow Maldistribution 12.2.1 Viscosity-Induced Flow Maldistribution

12.3 Mitigation of Flow Maldistribution 12.4 Header and Manifold Design

12.4.1 Oblique-Flow Headers 12.4.2 Normal-Flow Headers 12.4.3 Manifolds Summary References

748 749 755 756 759 762 763 763 765

766

77 1

775 776 779 783 786

787

79 1

796 800 80 1 802 804 809 809 810 82 1 834 837 837 844 845 848 852 852 853 853

CONTENTS x E

Review Questions Problems

13 Fouling and Corrosion 13.1 Fouling and its Effect on Exchanger Heat Transfer and Pressure Drop 13.2 Phenomenological Considerations of Fouling

13.2.1 Fouling Mechanisms 13.2.2 Single-Phase Liquid-Side Fouling 13.2.3 Single-Phase Gas-Side Fouling 13.2.4 Fouling in Compact Exchangers 13.2.5 Sequential Events in Fouling 13.2.6 Modeling of a Fouling Process

13.3.1 Fouling Resistance and Overall Heat Transfer Coefficient Calculation

13.3.2 Impact of Fouling on Exchanger Heat Transfer Performance 13.3.3 Empirical Data for Fouling Resistances

13.4 Prevention and Mitigation of Fouling 13.4.1 Prevention and Control of Liquid-Side Fouling 13.4.2 Prevention and Reduction of Gas-Side Fouling 13.4.3 Cleaning Strategies

13.5 Corrosion in Heat Exchangers 13.5.1 Corrosion Types 13.5.2 Corrosion Locations in Heat Exchangers 13.5.3 Corrosion Control Summary References Review Questions Problems

13.3 Fouling Resistance Design Approach

Appendix A: Thermophysical Properties Appendix B: E-NTU Relationships for Liquid-Coupled Exchangers Appendix C: Two-Phase Heat Transfer and Pressure Drop Correlations

C. 1 Two-Phase Pressure Drop Correlations C.2 Heat Transfer Correlations for Condensation C.3 Heat Transfer Correlations for Boiling

Appendix D: U and CuA Values for Various Heat Exchangers General References on or Related to Heat Exchangers Index

855 859 863 863 866 867 870 87 1 87 1 872 875 881

88 1 882 886 890 890 891 892 893 895 895 897 898 898 899 903 906 91 1 913 913 916 917 920 926 93 1