Engineering Heat Transfer (eBook)

Preface 5
Contents 7
Notation 10
Superscripts 11
1 Introduction to Heat Transfer 13
1.1 General Considerations 13
1.2 Modes of Heat Transfer 13
1.2.1 Conduction 14
1.2.2 Convection 14
1.2.3 Radiation 14
1.3 Laws of Heat Transfer 15
1.3.1 Conduction 15
1.3.2 Convection 16
1.3.3 Radiation 17
1.4 Overall Heat Transfer Coefficient 17
2 Steady Conduction 24
2.1 Introduction 24
2.2 Conduction through a Plane Wall 24
2.3 Conduction through a Plane Multiwall 11
2.4 Conduction through a Cylindrical Wall 11
2.5 Conduction through a Cylindrical Multiwall 32
2.6 Conduction through a Spherical Wall 34
2.7 Conduction through Liquids and Gases 35
3 Transient Conduction 39
3.1 Introduction 39
3.2 General Law of Thermal Conduction 40
3.3 Surface Temperature Variation in Infinite Thickness Walls 44
3.4 Surface Temperature Variation in Finite Thickness Walls 48
3.5 Immersed Plane Wall in Fluid at Different Temperature 53
3.6 Transient Conduction in Tubes 56
3.7 Fouriers Number 58
4 Dimensional Analysis 59
4.1 Introduction 59
4.2 Three Methods to Find Dimensionless Groups 61
4.2.1 Algebraic Method 61
4.2.2 Use of Differential Equations 63
4.2.3 Geometric, Kinematical and Dynamical Similitude 68
4.3 Theory of Models 70
5 Convection 72
5.1 Types of Motion 72
5.2 Physical Characteristics of Fluids 73
5.2.1 Water 74
5.2.1.1 Density 74
5.2.1.2 Specific Heat 74
5.2.1.3 Thermal Conductivity 74
5.2.1.4 Dynamic Viscosity 75
5.2.1.5 Prandtl's Number 75
5.2.2 Air 75
5.2.2.1 Density 75
5.2.2.2 Isobaric Specific Heat 76
5.2.2.3 Thermal Conductivity 76
5.2.2.4 Dynamic Viscosity 76
5.2.2.5 Prandtl's Number 77
5.2.3 Flue Gas 77
5.2.3.1 Density 77
5.2.3.2 Isobaric Specific Heat 78
5.2.3.3 Thermal Conductivity 79
5.2.3.4 Dynamic Viscosity 80
5.2.3.5 Prandtl's Number 80
5.3 Natural Convection 80
5.3.1 Plane Vertical Wall and Vertical Tubes 83
5.3.2 Horizontal Cylinders 85
5.3.3 Horizontal Plane Plates 88
5.3.4 Interspace Between two Plane Walls 89
5.4 Forced Convection Inside the Tubes 90
5.4.1 Water 93
5.4.2 Superheated Steam 97
5.4.3 Mineral Oils 101
5.4.4 Air 102
5.4.5 Different Kinds of Gas 104
5.5 Heat Transfer in the Initial Section 106
5.6 Special Instances 110
5.6.1 Annular Interspace 111
5.6.2 Plane Wall 112
5.7 Laminar Motion in the Tubes 114
5.8 Forced Convection Outside a Tube Bank 116
5.8.1 Introduction 116
5.8.2 Air 122
5.8.3 Various Types of Gas and Superheated Steam 122
5.9 Comparison Between In-Line and Staggered Arrangement 124
5.10 Heat Transfer to a Single Tube 126
5.11 Heat Transfer to Finned Tubes 128
5.12 Boiling Liquids 136
5.12.1 Boiling Liquids Outside the Tubes 136
5.12.2 Boiling Liquids Inside the Tubes 141
5.13 Condensing Vapors 144
6 Radiation 148
6.1 Introduction 148
6.2 The Laws of Radiation 149
6.2.1 Planck's Law 149
6.2.2 Wien's Law 151
6.2.3 Stefan-Boltzmann's Law 152
6.2.4 Kirchhoff's Law 154
6.2.5 Lambert-- Law -- Black Bodies Arranged in any Which Way 155
6.3 Plane Surfaces Facing Each Other 159
6.4 Body Completely Contained in Another Body 163
6.5 Solar Radiation 164
6.6 Flame Radiation 166
6.7 Flame Radiation and Convection 182
6.8 Radiation of CO 2 and Steam 189
7 Heat Exchangers and Tube Banks 199
7.1 Introduction 199
7.2 Mean Logarithmic Temperature Difference 200
7.3 Mean Specific Heat 204
7.3.1 Water and Superheated Steam 205
7.3.2 Air and Other Gases 205
7.4 Design Calculation 206
7.5 The Mean Difference in Temperature in Reality 207
7.5.1 Fluids with Cross Flow 209
7.5.2 Heat Exchangers 210
7.5.3 Coils 213
7.5.4 Tube Bank with Various Passages of the External Fluid 214
7.6 Verification Calculation 216
7.6.1 General Considerations 217
7.6.2 Fluids in Parallel Flow or in Counter flow 217
7.6.3 Factor in Real Cases 226
7.6.3.1 Fluids with Cross Flow 227
7.6.3.2 Heat Exchanger 228
7.6.3.3 Coils 229
7.6.3.4 Tube Bank with Various Passages of the External Fluid 230
8 Pressure Drops 232
8.1 Introduction 232
8.2 Distributed Pressure Drops 232
8.2.1 Turbulent Motion 232
8.2.2 Laminar Motion 246
8.3 Concentrated Pressure Drops 249
8.4 Pressure Drops through Tube Banks 256
8.5 Pressure Drop in Finned Tubes 259
A Thermal Characteristics of Materials 263
B Corrective Factors for the Design Computation in Real Cases 280
8.1 (D) Tube Bank with Several Passages of the External Fluid (Figs. 7.9 and 7.10) 299
C Corrective Factors for the Verification Computation in Real Cases 304
Bibliography 326
Index 329