Innovative Heat Exchangers (eBook)

Preface 5
Contents 7
Contributors 9
1 Polymer Film Heat Exchangers 11
Abstract 11
1 Introduction 15
2 Materials and Physical Properties 18
3 Wetting Characteristics 27
4 Heat Transfer 39
5 Scaling and Fouling 45
6 Conclusions 57
Acknowledgements 58
References 58
2 Polymer Composite Heat Exchangers 63
Abstract 63
1 Introduction 66
2 Polymer-Based Heat Exchangers 68
2.1 Comparison of Polymers with Metals for Use in Heat Exchangers 69
2.2 Polymer Heat Exchangers 71
2.3 Thermally Conductive Polymer Composites and Their Applications 72
2.4 Fouling on Polymer Surfaces 75
3 High-Performance Polymer Composite Tubes for Heat Exchangers 81
3.1 Material Selection 81
3.1.1 Polymer Matrix Materials 81
3.1.2 Thermally Conductive Fillers 84
3.2 Advanced Extrusion Process and Particle Orientation 87
4 Material Properties of High-Performance Polymer Composite Tubes 89
4.1 Thermal Properties 89
4.1.1 Thermal Conductivity Measurement 89
4.1.2 Thermal Conductivity 90
4.1.3 Thermal Expansion 91
4.2 Mechanical Properties 92
4.3 Lifetime Behaviour 93
5 Chemical Resistance 95
6 Experimental Investigations 97
6.1 Heat Transfer in Falling Film Evaporation 97
6.2 Crystallization Fouling on Polymer Composite Tubes 102
6.2.1 Calcium Sulphate Fouling in a Stirred Vessel Test Rig 102
6.2.2 Mixed Salt Fouling in a Horizontal Tube Falling Film Evaporator 106
7 Design Aspects 111
7.1 Mounting of Polymer Composite Tubes in Tube Plates 111
7.2 Flow-Induced Tube Vibrations 114
7.2.1 Reverse Bending Cycle and Vibration Tests 114
7.2.2 Maximum Unsupported Tube Span 115
7.3 Tube Geometries 118
8 Potential Applications 119
9 Conclusions and Future Prospects 122
Acknowledgements 123
References 123
3 Innovative Design of Microstructured Plate-and-Frame Heat Exchangers 127
Abstract 127
1 Introduction 128
2 Measures to Increase Heat Transfer 129
3 The Effect of Axial Heat Transfer 139
4 Applications of Microchannel Heat Exchangers 141
References 143
4 Heat Transfer in Evaporation on Micro- and Macrostructured Tubes 145
Abstract 145
1 Introduction 147
2 Calculation Method for Heat Transfer for Practical Belongs 150
3 Surface Characterization of the Micro- and Macrostructure 159
4 Influence of the Microstructure on the Heat Transfer 165
5 Influence of the Macrostructure on Heat Transfer 169
6 Conclusion 174
References 175
5 Multi-stream Plate-and-Frame Heat Exchangers for Condensation and Evaporation 177
Abstract 177
1 The Multi-stream Concept 180
2 State of the Art 184
3 Single-Phase Flow and Flow Pattern 184
4 Pressure Drop and Heat Transfer of Two-Phase Flow in PHE 188
5 Entropy Production in Plate Heat Exchangers 193
References 196
6 Low-Finned Tubes for Condensation 198
Abstract 198
1 Basics on Condensation 201
2 Basics on Low-Finned Tubes 203
2.1 Definition of Surface Area 203
2.2 Fluid Dynamics and Flooding Angle 206
3 Single Tubes and Tube Bundles 208
4 Condensation of Pure Substances 211
4.1 Free Convection 213
4.2 Forced Convection 219
4.3 Special Cases: High Surface Tension 220
4.4 Theoretical Models 221
4.5 Summary 226
5 Condensation of Mixtures 227
5.1 Basics on the Condensation of Mixtures 228
5.2 Condensation on Low-Finned Tubes 230
5.3 Theoretical Models 235
5.4 Summary 237
References 238
7 Pillow-Plate Heat Exchangers: Fundamental Characteristics 241
Abstract 241
1 Introduction 243
1.1 Manufacturing and Operating Principle 243
1.2 Basic Design 245
1.3 General Application Areas 248
2 Geometry Characteristics 248
2.1 Heat Transfer Area 250
2.2 Cross-sectional Area 251
2.3 Characteristic Lengths 252
2.4 Welding Points 252
References 252
8 Single-Phase Flow and Condensation in Pillow-Plate Condensers 254
Abstract 254
1 Introduction 256
2 Applications in Condensation 256
3 Condenser Design 259
4 Cooling Stage 261
4.1 Heat Transfer 262
4.2 Fluid Dynamics 265
5 Condensation Stage Heat Transfer 266
6 Pillow-Plate Condensers for the Future Applications 270
6.1 Additional Inserts 270
6.2 Surface Structuring 271
References 272
9 Pillow Plate Heat Exchangers as Falling Film Evaporator or Thermosiphon Reboiler 273
Abstract 273
1 Introduction 275
2 Pillow Plate Falling Film Evaporators 275
2.1 Design and Operating Principle 276
2.2 Minimum Wetting Rate and Average Film Thickness 277
2.3 Flow Pattern and Film Thickness Distribution 280
2.4 Heat Transfer 283
3 Pillow Plate Thermosiphon Reboilers 283
3.1 Experimental Test Rig for Pillow Plate Thermosiphon Reboiler 284
3.2 Operating Principle and Characteristics 285
3.2.1 Characteristic Temperature Profiles 286
3.2.2 Fluid dynamic Behavior 287
3.3 Heat Transfer Performance of Pillow Plate Thermosiphon Reboilers 290
3.3.1 Single-Component Evaporation 290
3.3.2 Mixture Evaporation 292
3.4 Thermal Modeling and Simulation 295
3.4.1 Extraction of Experimental Heat Transfer Coefficients 295
3.4.2 Estimation of Single-Phase Heat Transfer Coefficients 296
3.4.3 Estimation of Evaporation Heat Transfer Coefficients 297
4 Summary 298
References 299
10 hiTRAN® Thermal Systems in Tubular Heat Exchanger Design 301
Abstract 301
1 Introduction 303
2 hiTRAN® Thermal Systems in Single-Phase Pipe Flow 304
2.1 Hydrodynamics in Adiabatic Pipe Flow with hiTRAN 304
2.2 Heat Transfer Characteristics in Viscous Empty Tube Flow 306
2.2.1 Thermal Stratification 307
2.3 Enhanced Heat Transfer and Flow Distribution in hiTRAN® Flow 310
2.3.1 Elimination of Flow Stratification with hiTRAN 313
2.3.2 Improved Bundle Fluid Distribution 315
2.3.3 Summary of hiTRAN® Thermal Systems in Single-Phase Flow 315
2.4 Revamp in Single-Phase Applications 316
2.4.1 Modification of Pass Arrangement 316
2.4.2 Switch of Shell Arrangement 317
2.4.3 Part Installation of hiTRAN 318
2.5 Case Study 318
3 hiTRAN® Thermal Systems in Two-Phase Pipe Flow 320
3.1 hiTRAN® in Condensing Applications 320
3.1.1 Single-Component Condensation with hiTRAN 321
3.1.2 MultiComponent Condensation with hiTRAN 322
3.1.3 Condensation in Horizontal Tubes 324
3.1.4 Subcooling of Condensate 325
3.2 hiTRAN® in Boiling Applications 325
3.2.1 Shell and Tube Side Reboilers 327
3.2.2 Shell and Tube Vaporizers 329
3.2.3 Falling Film Evaporators 335
3.2.4 Summary of the Use of hiTRAN® Technology in Two-Phase Flow Applications 338
4 Fouling in Tubular Heat Exchangers Equipped with hiTRAN® Thermal Systems 339
4.1 Increased Wall Shear 339
4.2 Change in Tube Wall Temperatures 340
4.3 Residence Time at Elevated Temperatures 342
4.4 Waxing Fouling in Air Coolers 342
References 343
11 EMbaffle® Heat Exchange Technology 346
Abstract 346
1 Introduction 348
2 Principles of EMbaffle® Technology 350
3 The Advantage of EMbaffle® Technology 353
3.1 Vibrations in EMbaffle® 353
3.2 LMTD in EMbaffle® 356
3.3 EMbaffle® in Limited Pressure Drops Services 357
3.4 Fouling in EMbaffle® 358
4 Advanced EMbaffle® Designs 360
5 EMbaffle® Design Cases 362
5.1 Design Case-1: Overhead Gas Cooler 362
5.2 Design Case-2: Cycle Gas Cooler 364
References 365
12 Innovative Adsorbent Heat Exchangers: Design and Evaluation 367
Abstract 367
1 Introduction 369
2 Adsorbent Materials and Coatings 373
3 Heat Exchanger Design Criteria 376
3.1 COP-Based Pre-evaluation of Adsorbent Heat Exchanger Designs 379
3.2 Analyzing Heat and Mass Transfer Resistances 384
3.2.1 Resistance–Capacitance Model 384
3.2.2 Analysis of Resistances 385
3.2.3 Resistance Evaluation and Overall Resistance 387
3.2.4 Detailed Heat and Mass Transfer Analysis 389
3.3 Typical and Attractive Heat Exchanger Geometries 389
4 Improved Adsorbent Heat Exchangers—Examples 391
4.1 Finned-Tube Heat Exchanger with Granules 391
4.2 Fin-and-Tube Heat Exchanger with Binder-Based Coating 393
4.3 Fiber-and-Tube Heat Exchanger with Direct Crystallization 394
References 395