2nd Edition

Principles of Enhanced Heat Transfer

    818 Pages 448 B/W Illustrations
    by CRC Press

    This book is essential for anyone involved in the design of high-performance heat exchangers or heat devices, also known as "second generation heat transfer technology." Enhanced surfaces are geometrics with special shapes that promote much higher rates of heat transfer than smooth or plain surfaces. This revision presents the subject matter just beyond the introductory level and traces the advancement of heat transfer research in areas such as integral-fin and micro-fin tubes, complex plate-fin geometries, and micro-channels for single-phase and two-phase applications.

    CHAPTER 1: INTRODUCTION TO ENHANCED HEAT TRANSFER

    1.1 INTRODUCTION

    1.2 THE ENHANCEMENT TECHNIQUES
    Passive Techniques
    Active Techniques

    1.2.3 Technique vs. Mode

    1.3 PUBLISHED LITERATURE
    General Remarks
    U.S. Patent Literature
    Manufacturer's Information

    1.4 BENEFITS OF ENHANCEMENT

    1.5 COMMERCIAL APPLICATIONS OF ENHANCED SURFACES
    Heat (and Mass) Exchanger Types of Interest
    Illustrations of Enhanced Tubular Surfaces
    Enhanced Fin Geometries for Gases
    Plate Type Heat Exchangers
    Cooling Tower Packings
    Distillation and Column Packings
    Factors Affecting Commercial Development

    1.6 DEFINITION OF HEAT TRANSFER AREA

    1.7 POTENTIAL FOR ENHANCEMENT
    PEC Example 1.1
    PEC Example 1.2

    1.8 REFERENCES

    CHAPTER 2: HEAT TRANSFER FUNDAMENTALS

    2.l INTRODUCTION

    2.2 HEAT EXCHANGER DESIGN THEORY
    Thermal Analysis
    Heat Exchanger Design Methods
    Comparison of LMTD and NTU Design Methods

    2.3 FIN EFFICIENCY

    2.4 HEAT TRANSFER COEFFICIENTS AND FRICTION FACTORS
    Laminar Flow Over Flat Plate
    Laminar Flow in Ducts
    Turbulent Flow in Ducts
    Tube Banks (Single-Phase Flow)
    Film Condensation
    Nucleate Boiling

    2.5 CORRECTION FOR VARIATION OF FLUID PROPERTIES
    Effect of Changing Fluid Temperature
    Effect Local Property Variation

    2.6 REYNOLDS ANALOGY

    2.7 FOULING OF HEAT TRANSFER SURFACES

    2.8 CONCLUSIONS

    2.9 REFERENCES

    2.10 NOMENCLATURE


    CHAPTER 3: PERFORMANCE EVALUATION CRITERIA FOR SINGLE-PHASE FLOWS

    3.1 PERFORMANCE EVALUATION CRITERIA (PEC)

    3.2 PEC FOR HEAT EXCHANGERS

    3.3 PEC FOR SINGLE PHASE FLOW
    Objective Function and Constraints
    Algebraic Formulation of the PEC
    Simple Surface Performance Comparison
    Constant Flow Rate
    Fixed Flow Area

    3.4 THERMAL RESISTANCE ON BOTH SIDES

    3.5 RELATIONS FOR St AND f

    3.6 HEAT EXCHANGER EFFECTIVENESS

    3.7 EFFECT OF REDUCED EXCHANGER FLOW RATE

    3.8 FLOW NORMAL TO FINNED TUBE BANKS

    3.9 VARIANTS OF THE PEC

    3.10 COMMENTS ON OTHER PERFORMANCE INDICATORS
    Shah
    Soland et al.

    3.11 CONCLUSIONS

    3.12 REFERENCES

    3.13 NOMENCLATURE

    CHAPTER 4: PERFORMANCE EVALUATION CRITERIA FOR TWO-PHASE HEAT EXCHANGERS

    4.1 INTRODUCTION

    4.2 OPERATING CHARACTERISTICS OF TWO-PHASE HEAT EXCHANGERS

    4.3 ENHANCEMENT IN TWO-PHASE HEAT EXCHANGE SYSTEMS
    Work Consuming Systems
    Work Producing Systems
    Heat Actuated Systems

    4.4 PEC FOR TWO-PHASE HEAT EXCHANGE SYSTEMS

    4.5 PEC CALCULATION METHOD
    PEC Example 4.1
    PEC Example 4.2

    4.6 CONCLUSIONS

    4.7 REFERENCES

    4.8 NOMENCLATURE

    CHAPTER 5: PLATE-AND-FIN EXTENDED SURFACES

    5.1 INTRODUCTION

    5.2 OFFSET-STRIP FIN
    5.2.1 Enhancement Principle
    5.2.2 PEC Example 5.1
    5.2.3 Analytically Based Models for j and f vs. Re
    5.2.4 Transition from Laminar to Turbulent Region
    5.2.5 Correlations for j and f vs. Re
    5.2.6 Use of OSF with Liquids
    5.2.7 Effect of Percent Fin Offset
    5.2.7 Effect of Burred Edges

    5.3 LOUVER FIN
    5.3.1 Heat Transfer and Friction Correlations
    5.3.2 Flow Structure in the Louver Fin Array
    5.3.3 Analytical Model for Heat Transfer and Friction
    5.3.4 PEC Example 5.2

    5.4 CONVEX LOUVER FIN

    5. 5 WAVY FIN

    5.6 3-DIMENSIONAL CORRUGATED FINS

    5.7 PERFORATED FIN

    5.8 PIN FINS AND WIRE MESH

    5.9 VORTEX GENERATORS
    5.9.1 Types of Vortex Generators
    5.9.2 Vortex Generators on a Plate-Fin Surface

    5.10 METAL FOAM FIN

    5.11 PLAIN FIN
    PEC Example 5.3

    5.12 ENTRANCE LENGTH EFFECTS

    5.13 PACKINGS FOR GAS-GAS REGENERATORS

    5. 14 NUMERICAL SIMULATION
    5.14.1 Offset-strip fins
    5.14.2 Louver Fins
    5. 14.3 Wavy Channels
    5.14.4 Chevron Plates
    5.14.5 Summary

    5.15 CONCLUSIONS

    5.16 REFERENCES

    5.13 NOMENCLATURE

    CHAPTER 6: EXTENDED SURFACES OUTSIDE TUBES

    6.1 INTRODUCTION

    6.2 THE GEOMETRIC PARAMETERS AND THE REYNOLDS NUMBER
    Dimensionless Variables
    Definition of Reynolds Number
    Definition of the Friction Factor
    Sources of Data

    6.3 PLAIN PLATE-FINS ON ROUND TUBES
    Effect of Fin Spacing
    Correlations for Staggered Tube Geometries
    Correlations for Inline Tube Geometries

    6.4 PLAIN INDIVIDUALLY FINNED TUBES
    Circular Fins with Staggered Tubes
    Low Integral-Fin Tubes

    6.5 ENHANCED PLATE FIN GEOMETRIES WITH ROUND TUBES
    Wavy Fin
    Offset Strip Fins
    Convex Louver Fins
    Louvered Fin
    Perforated Fins
    Mesh Fins
    Vortex Generators

    6.6 ENHANCED CIRCULAR FIN GEOMETRIES
    Illustrations of Enhanced Fin Geometries
    Spine or Segmented Fins
    Wire Loop Fins

    6.7 OVAL AND FLAT TUBE GEOMETRIES
    Oval vs. Circular Individually Finned Tubes
    Flat Extruded Aluminum Tubes with Internal Membranes
    Plate-and-Fin Automotive Radiators
    Vortex Generators on Flat or Oval Fin-Tube Geometry

    6.8 ROW EFFECTS - STAGGERED AND INLINE LAYOUTS

    6.9 HEAT TRANSFER COEFFICIENT DISTRIBUTION (PLAIN FINS)
    Experimental Methods
    Plate Fin and Tube Measurements
    Circular Fin and Tube Measurements

    6.10 PERFORMANCE COMPARISON OF DIFFERENT GEOMETRIES
    Geometries Compared
    Analysis Method
    Calculated Results

    6. 11 PROGRESS ON NUMERICAL SIMULATION

    6.12 RECENT PATENTS ON ADVANCED FIN GEOMETRIES

    6.13 HYDROPHILIC COATINGS

    6.14 CONCLUSIONS

    6.15 REFERENCES

    6.16 NOMENCLATURE

    CHAPTER 7: INSERT DEVICES FOR SINGLE PHASE FLOW

    7.1 INTRODUCTION

    7.2 TWISTED TAPE INSERT
    Laminar Flow
    Predictive Methods for Laminar Flow
    Turbulent Flow
    PEC Example 7.1
    Twisted Tapes in Annuli
    Twisted Tapes in Rough Tubes

    7.3 SEGMENTED TWISTED TAPE INSERT

    7.4 DISPLACED ENHANCEMENT DEVICES
    Turbulent Flow
    Laminar Flow
    PEC Example 7.2

    7.5 WIRE COIL INSERTS
    Laminar Flow
    Turbulent Flow

    7.6 EXTENDED SURFACE INSERT

    7.7 TANGENTIAL INJECTION DEVICES

    7.8 CONCLUSIONS

    7.9 REFERENCES

    7.10 NOMENCLATURE

    CHAPTER 8: INTERNALLY FINNED TUBES AND ANNULI

    8.1 INTRODUCTION

    8.2 INTERNALLY FINNED TUBES
    Laminar Flow
    Turbulent Flow
    PEC Example 1

    8.3 SPIRALLY FLUTED TUBES
    The General Atomics Spirally Fluted Tube
    Spirally Indented Tube

    8.4 ADVANCED INTERNAL FIN GEOMETRIES

    8.5 FINNED ANNULI

    8.6 CONCLUSIONS

    8.7 REFERENCES

    8.8 NOMENCLATURE

    CHAPTER 9 INTEGRAL ROUGHNESS

    9.1 INTRODUCTION

    9.2 ROUGHNESS WITH LAMINAR FLOW

    9.3 HEAT-MOMENTUM TRANSFER ANALOGY CORRELATION
    Friction Similarity Law
    PEC Example 9.1
    Heat Transfer Similarity Law
    Smooth Surfaces
    Rough Surfaces

    9.4 TWO-DIMENSIONAL ROUGHNESS
    Transverse Rib Roughness
    Integral Helical-Rib Roughness
    Wire Coil Inserts
    Corrugated Tube Roughness
    PEC Example 9.2

    9.5 THREE-DIMENSIONAL ROUGHNESS

    9.6 PRACTICAL ROUGHNESS APPLICATIONS
    Tubes with Inside Roughness
    Rod Bundles and Annuli
    Rectangular Channels
    Outside Roughness for Cross Flow

    9.7 GENERAL PERFORMANCE CHARACTERISTICS
    St and f vs. Reynolds Number
    Other Correlating Methods
    Prandtl Number Dependence

    9.8 HEAT TRANSFER DESIGN METHODS
    Design Method 1
    Design Method 2

    9.9 PREFERRED ROUGHNESS TYPE AND SIZE
    Roughness Type
    PEC Example 9.3

    9.10 NUMERICAL SIMULATION
    Predictions for Transverse-Rib Roughness
    Effect of Rib Shape
    The Discrete-Element Predictive Model

    9.11 CONCLUSIONS

    9.12 REFERENCES

    9.12 NOMENCLATURE




    CHAPTER 10: FOULING ON ENHANCED SURFACES

    10.1 INTRODUCTION

    10.2 FOULING FUNDAMENTALS
    Particulate Fouling

    10.3 FOULING OF GASES ON FINNED SURFACES

    10.4 SHELL SIDE FOULING OF LIQUIDS
    Low Radial Fins
    Axial Fins and Ribs in Annulus
    Ribs in Rod Bundle

    10.5 FOULING OF LIQUIDS IN INTERNALLY FINNED TUBES

    10.6 LIQUID FOULING IN ROUGH TUBES
    Accelerated Fouling
    Long Term Fouling

    10.7 LIQUID FOULING IN PLATE-FIN GEOMETRY

    10.8 CORRELATIONS FOR FOULING IN ROUGH TUBES

    10.9 MODELING OF FOULING IN ENHANCED TUBES

    10.10 FOULING IN PLATE HEAT EXCHANGERS

    10.11 CONCLUSIONS

    10.12 REFERENCES

    10.13 NOMENCLATURE

    CHAPTER 11 POOL BOILING

    11.1 INTRODUCTION

    11.2 EARLY WORK ON ENHANCEMENT (1931-1962)

    11.3 SUPPORTING FUNDAMENTAL STUDIES

    11.4 TECHNIQUES EMPLOYED FOR ENHANCEMENT
    Abrasive Treatment
    Open Grooves
    Three-Dimensional Cavities
    Etched Surfaces
    Electroplating
    Pierced Three-dimensional Cover Sheets
    Attached Wire and Screen Promoters
    Nonwetting Coatings
    Oxide and Ceramic Coatings
    Porous Surfaces
    Structured Surfaces (Integral Roughness)
    Combination Structured and Porous Surfaces
    Composite Surfaces

    11.5 SINGLE-TUBE POOL BOILING TESTS OF ENHANCED SURFACES

    11.6 THEORETICAL FUNDAMENTALS
    Liquid Superheat
    Effect of Cavity Shape and Contact Angle on Superheat
    Entrapment of Vapor in Cavities
    Effect of Dissolved Gases
    Nucleation at a Surface Cavity
    Bubble Departure Diameter
    Bubble Dynamics

    11.7 BOILING HYSTERESIS AND ORIENTATION EFFECTS
    Hysteresis Effects
    Size and Orientation Effects

    11.8 BOILING MECHANISM ON ENHANCED SURFACES
    Basic Principles Employed
    Visualization of Boiling in Subsurface Tunnels
    Boiling Mechanism in Subsurface Tunnels
    Chien and Webb Parametric Boiling Studies

    11.9 PREDICTIVE METHODS FOR STRUCTURED SURFACES
    Empirical Correlations
    Nakayama et al. [1980b]
    Chien and Webb Model
    Ramaswamy et al. Model [2003]
    Jiang et al. Model [2001]
    Other Models
    Evaluation of Models

    11.10 BOILING MECHANISM ON POROUS SURFACES
    O'Neill et al. Thin Film Concept
    Kovalev et al. [1990] Concept

    11.11 PREDICTIVE METHODS FOR POROUS SURFACES
    O'Neill et al. [1972] Model
    Kovalov et al. [1990] Model
    Nishikawa et al. [1983] Correlation
    Zhang and Zhang [1992] Correlation

    11.12 CRITICAL HEAT FLUX

    11.13 ENHANCEMENT OF THIN FILM EVAPORATION

    11.14 CONCLUSIONS

    11.15 REFERENCES

    11.16 NOMENCLATURE

    CHAPTER 12: VAPOR SPACE CONDENSATION

    12.1 INTRODUCTION
    Condensation Fundamentals
    Basic Approaches to Enhanced Film Condensation

    12.2 DROPWISE CONDENSATION

    12.3 SURVEY OF ENHANCEMENT METHODS
    Coated Surfaces
    Roughness
    Horizontal Integral-Fin Tubes
    Corrugated Tubes
    Surface Tension Drainage
    Vertical Fluted Tubes
    Electric Fields

    12.4 SURFACE TENSION DRAINED CONDENSATION
    Fundamentals
    Adamek's Generalized Analysis
    Practical Fin Profiles
    Prediction for Trapezoidal Fin Shapes

    12.5 HORIZONTAL INTEGRAL-FIN TUBE
    The Beatty and Katz Model
    Precise Surface Tension Drained Models
    Approximate Surface Tension Drained Models
    Comparison of Theory and Experiment

    12.6 HORIZONTAL TUBE BANKS
    Condensate Inundation without Vapor Shear
    Condensate Drainage Pattern
    Prediction of the Condensation Coefficient

    12.7 CONCLUSIONS

    12.8 REFERENCES

    12.9 NOMENCLATURE

    APPENDIX A: THE KEDZIERSKI AND WEBB [1990] FIN PROFILE SHAPES

    APPENDIX B: FIN EFFICIENCY IN THE FLOODED REGION

    CHAPTER 13 CONVECTIVE VAPORIZATION

    13.1 INTRODUCTION

    13.2 FUNDAMENTALS
    Flow Patterns
    Convective Vaporization in Tubes
    Two-Phase Pressure Drop
    Effect of Flow Orientation on Flow Pattern
    Convective Vaporization in Tube Bundles
    Critical Heat Flux

    13.3 ENHANCEMENT TECHNIQUES IN TUBES
    Internal Fins
    Swirl Flow Devices
    Roughness
    Coated Surfaces
    Perforated Foil Inserts
    Porous Media
    Coiled Tubes and Return Bends

    13.4 THE MICROFIN TUBE
    Early Work on the Microfin Tube
    Recent Work on the Microfin Tube
    Special Microfin Geometries
    Microfin Vaporization Data

    13.5 MINI-CHANNELS

    13.6 CRITICAL HEAT FLUX (CHF)
    Twisted Tape
    Grooved Tubes
    Mesh Inserts

    13.7 PREDICTIVE METHODS FOR IN-TUBE FLOW
    High Internal Fins
    Microfins
    Twisted Tape Inserts
    Corrugated Tubes
    Porous Coatings

    13.8 TUBE BUNDLES
    Convective Effects in Tube Bundles
    Starting Hysteresis in Tube Bundles

    13.9 PLATE-FIN HEAT EXCHANGERS

    13.10 THIN FILM EVAPORATION
    Horizontal Tubes
    Vertical Tubes

    13.11 CONCLUSIONS

    13.12 REFERENCES

    CHAPTER 14: CONVECTIVE CONDENSATION

    14.1 INTRODUCTION

    14.2 FORCED CONDENSATION INSIDE TUBES
    Internally Finned Tubes
    Twisted-tape Inserts.
    Roughness

    Coiled Tubes and Return Bends








    14.3 MICROFIN TUBE
    Microfin Geometry Details
    Optimization of Internal Geometry
    Condensation Mechanism in Microfin Tubes
    Convective Condensation in Special Microfin Geometries

    14.4 FLAT TUBE AUTOMOTIVE CONDENSERS
    Condensation Data for Flat, Extruded Tubes
    Other Predictive Methods of Condensation in Flat Tubes

    14.5 PLATE-TYPE HEAT EXCHANGERS

    14.6 NON-CONDENSIBLE GASES

    14.7 PREDICTIVE METHODS FOR CIRCULAR TUBES
    High Internal Fins
    Wire Loop Internal Fins
    Twisted-tapes
    Roughness
    Microfins

    14.8 CONCLUSIONS

    14.8 REFERENCES

    14.9 NOMENCLATURE

    CHAPTER 15 ENHANCEMENT USING ELECTRIC FIELDS

    15.1 INTRODUCTION

    15.2 ELECTRODE DESIGN AND PLACEMENT

    15.3 SINGLE-PHASE FLUIDS
    15.3.1 Enhancement on Gas Flow
    15.3.2 Enhancement on Liquid Flow
    15.3.3 Numerical Studies

    15.4 CONDENSATION
    15.4.1 Fundamental Understanding
    15.4.2 Vapor Space Condensation
    15.4.3 In-tube Condensation
    15.4.4 Falling Film Evaporation
    15.4.5 Correlations

    15.5 BOILING
    15.5.1 Fundamental Understanding
    15.5.2 Pool Boiling
    15.5.3 Convective Vaporization
    15.5.4 Critical Heat Flux
    15.5.5 Correlations

    15.6 CONCLUSIONS

    15.7 REFERENCES

    15.8 NOMENCLATURE

    CHAPTER 16: SIMULTANEOUS HEAT AND MASS TRANSFER

    16.1 INTRODUCTION

    16.2 MASS TRANSFER RESISTANCE IN THE GAS PHASE
    Condensation with Noncondensible Gases
    Evaporation into Air
    Dehumidifying Finned-Tube Heat Exchangers
    Water Film Enhancement of Finned Tube Exchanger

    16.3 CONTROLLING RESISTANCE IN LIQUID PHASE

    16.4 SIGNIFICANT RESISTANCE IN BOTH PHASES

    16.5 CONCLUSIONS

    16.6 REFERENCES

    16.7 NOMENCLATURE

    CHAPTER 17 ADDITIVES FOR GASES AND LIQUIDS

    17.1 INTRODUCTION

    17.2 ADDITIVES FOR SINGLE-PHASE LIQUIDS
    Solid Particles
    PEC Example
    Gas Bubbles
    Suspensions in Dilute Polymer and Surfactant Solutions

    17.3 ADDITIVES FOR SINGLE-PHASE GASES
    Solid Additives
    Liquid Additives

    17.4 ADDITIVES FOR BOILING

    17.5 ADDITIVES FOR CONDENSATION

    17.6 CONCLUSIONS

    17.7 REFERENCES

    17.8 NOMENCLATURE

    CHAPTER 18 MICRO-CHANNELS

    18.1 INTRODUCTION

    18.2 FRICTION IN SINGLE MICRO-CHANNELS

    18.3 FRICTION IN A SINGLE CHANNEL VS. MULTI-CHANNELS

    18.4 SINGLE-PHASE HEAT TRANSFER IN MICRO-CHANNELS
    18.4.1 Single Channel Flow
    18.4.2 Heat Transfer in Multiple Micro-channels

    18.5 MANIFOLD SELECTION AND DESIGN
    18.5.1 Single-Phase Flow
    18.5.2 Two-Phase Flow

    18.6 NUMERICAL SIMULATION OF FLOW IN MANIFOLDS

    18.7 TWO-PHASE HEAT TRANSFER IN MICRO-CHANNELS

    18.8 CONCLUSIONS

    18.9 REFERENCES

    18.10 NOMENCLATURE

    CHAPTER 19 ELECTRONIC COOLING HEAT TRANSFER

    19.1 INTRODUCTION

    19.2 COMPONENT THERMAL RESISTANCES

    19.3 LIMITS ON DIRECT HEAT REMOVAL WITH AIR-COOLING (DirHR)
    19.3.1 PEC Example 19.1 Enhanced Fin Geometry Heat Sink
    Table 19.1 Performance Of Plain Fin And Offset Strip Fin Heat Sinks.

    19.4 2nd GENERATION IndHR DEVICES FOR HEAT REMOVAL AT HOT SOURCE
    19.4.1 Single-Phase Fluids
    19.4.2 Two-Phase Fluids
    19.4.3 Heat Pipe
    19.4.4 Nucleate Boiling
    19.4.5 Forced Convection
    19.4.6 Spray Cooling

    19.5 DISCUSSION OF ADVANCED HEAT REMOVAL CONCEPTS
    19.5.1 Jet Impingement/Spray Cooling Devices
    19.5.2 Single-Phase Micro-Channel Cooling
    19.5.3 Two-Phase Micro-Channel Cooling
    19.5.4 Enhanced Two-Phase Forced Convection Cooling

    19.6 REMOTE HEAT-EXCHANGERS FOR IndHR
    19.6.1 Air-Cooled Ambient Heat-Exchangers
    19.6.2 Condensing Surfaces
    19.6.3 Design for Multiple Heat Sources

    19.7 SYSTEM PERFORMANCE FOR THE IndHR SYSTEM

    19.8 CONCLUSIONS

    19.9 REFERENCES

    19.10 NOMENCLATURE

    PROBLEM SUPPLEMENT

    INDEX

    Biography

    Ralph L. Webb is a Professor Emeritus of Mechanical Engineering at the Pennsylvania State University. He received his Ph.D. from the University of Minnesota, and has published over 275 papers in the general area of heat transfer enhancement and has eight U.S. patents on enhanced heat transfer surfaces. He has performed research on enhanced heat transfer in boiling, condensation, fouling, air-cooled heat exchangers, electronic equipment cooling, forced convection for gases and liquids, wetting coatings to promote drainage of thin liquid films, and frost formation.
    Prof. Webb is the Founding Editor and Editor-in-Chief of the Journal of Enhanced Heat Transfer and is an editor of Heat Transfer Engineering journal. He is a recipient of the ASME Heat Transfer Memorial Award, the UK Refrigeration Institute Hall-Thermotank Gold Medal, and the AIChE Donald Q. Kern award. He is also a Fellow of ASME and ASHRAE and a Life Member of ASME.

    Nae-Hyun Kim is a Professor of Mechanical Engineering at the University of Incheon, Korea. He earned his Ph.D. at the Pennsylvania State University in 1989 under the supervision of Prof. Webb. Since then, he has been closely working with air-conditioning and refrigeration industries, where enhanced heat transfer technology has been successfully employed. Prof. Kim has published more than 30 international journal and conference papers related to boiling, condensation, fouling, and forced convection of liquids and gases. He is a member of ASME and ASHRAE.