Tunnel Fire Dynamics (eBook)

Preface 5
Acknowledgement 7
Contents 8
Chapter-1 15
Introduction 15
1.1 Introduction 15
1.2 Characteristics of Tunnel Fires 16
1.3 Mitigation Systems in Tunnels 20
1.4 Incidents in Tunnel 23
1.4.1 Fires in Road Tunnels 23
1.4.2 Fires in Rail Tunnels 31
1.4.3 Fires in Metro Tunnels 33
1.5 Summary 34
References 34
Chpater-2 36
Fuel and Ventilation Controlled Fires 36
2.1 Introduction 36
2.2 Fire Development in Building Fires 36
2.3 Fire Development in Tunnel Fires 38
2.4 Fuel or Ventilation Control in a Compartment Fire 42
2.5 Fuel or Ventilation Control in a Tunnel with Longitudinal Flow 46
2.5.1 Fuel Control 47
2.5.2 Ventilation Control 48
2.5.3 Determination of Combustion Mode 48
2.6 Effects of Vitiation on the Combustion Process 53
2.7 Summary 54
References 55
Chapter-3 57
Tunnel Fire Tests 57
3.1 Introduction 57
3.2 Overview of Large-Scale Tunnel Experiments 58
3.3 Large-Scale Tunnel Fire Tests 64
3.3.1 Ofenegg 1965 64
3.3.2 Glasgow 1970 67
3.3.3 The West Meon Tests in Early 1970s 68
3.3.4 Zwenberg 1975 68
3.3.5 P.W.R.I 1980 73
3.3.6 TUB-VTT Tests 1986 76
3.3.7 EUREKA EU499 Tests 1990–1992 77
3.3.8 Memorial Tunnel Tests 1993–1995 80
3.3.9 Shimizu No. 3 2001 83
3.3.10 2nd Benelux Tests 2002 84
3.3.11 Runehamar 2003 88
3.3.12 METRO Tests 2011 90
3.3.13 Carleton University Laboratory Train Tests 2011 92
3.3.14 Singapore Tests 2011 93
3.3.15 Runehamar Test 2013 93
3.4 Model Scale Fire Tests 93
3.4.1 The TNO Tests 94
3.4.2 Automatic Water Spray System Tests 94
3.4.3 Longitudinal Ventilation Tests 94
3.4.4 Point Extraction Ventilation Tests 95
3.4.5 Tunnel Cross-Section Tests 95
3.5 Summary 95
References 96
Chapter-4 100
Heat Release Rates in Tunnels 100
4.1 Introduction 100
4.2 Measured HRR in Different Vehicles 101
4.2.1 Road Vehicles 101
4.2.1.1 Passenger Cars 104
4.2.1.2 Buses 107
4.2.1.3 Heavy Goods Vehicles 110
4.2.1.4 Tanker Fires 115
4.2.1.5 Pool Fires (Liquid) 116
4.2.1.6 Construction Vehicles 120
4.2.1.7 Rubber Tyres 121
4.2.2 Railway Rolling Stock 123
4.3 Parameters Influencing the HRR 123
4.3.1 Heat Feedback 123
4.3.2 Effects of Tunnel Geometry 128
4.3.3 Effects of Ventilation on Peak HRR 128
4.3.4 Fuel-Controlled Fires 130
4.3.5 Ventilation-Controlled Fires 132
4.4 HRR per Exposed Fuel Surface Area 134
4.4.1 Liquids 136
4.4.2 Solid Materials 137
4.4.3 Vehicle Fires 138
4.5 Summary 140
References 141
Chapter-5 146
Fire Growth Rates in Tunnels 146
5.1 Introduction 146
5.2 Theory of Fire Growth Rate 149
5.2.1 Opposed Flow Spread (Upstream) 150
5.2.2 Wind-Aided Spread (Downstream) 151
5.2.3 Relationship Between FGR and Flame Spread Rate 152
5.2.4 Fuels Consisting of Several Parts 153
5.3 Correlations for Fire Growth Rate 154
5.3.1 Comparison with Model Scale Tests 155
5.3.2 Comparison with Full Scale Tests 156
5.4 The Effects of Windbreaks on Fire Growth Rates 158
5.5 Summary 160
References 161
Chapter-6 163
Design Fire Curves 163
6.1 Introduction 163
6.2 Design Fire Methods 165
6.2.1 Constant Values for Design Fires 165
6.2.2 Time Dependent Methods for Design Fires 168
6.3 Exponential Design Fire Curve Method with Superposition 172
6.3.1 Determination of Design Fire Scenarios 173
6.3.2 Maximum Heat Release Rate 174
6.3.3 Time to Maximum Heat Release Rate 176
6.3.4 Energy Content 177
6.3.5 Reconstruction of a Large Scale Test 177
6.3.6 Design Fire for a Tram Carriage 178
6.3.7 Design Fire for a Road Vehicle 180
6.4 New Concept for Design Curves 181
6.4.1 Theoretical Aspects 182
6.4.2 Calculation 183
6.5 Summary 185
References 186
Chapter-7 188
Combustion Products from Fires 188
7.1 Introduction 188
7.2 Combustion and Fire Chemistry 189
7.3 Yields 192
7.4 Emissions from Fires in Vehicles and Tunnels 195
7.5 Effect of Ventilation Condition 202
7.6 Summary 212
References 213
Chapter-8 216
Gas Temperatures 216
8.1 Introduction 216
8.2 Interaction of Ventilation Flow with Fire Plume 218
8.3 Maximum Ceiling Gas Temperature 220
8.3.1 Fire Plume Mass Flow Rate in a Ventilated Flow 220
8.3.2 Maximum Ceiling Gas Temperature in a Small Fire 222
8.3.3 Maximum Ceiling Gas Temperature in a Large Fire 223
8.4 Position of Maximum Ceiling Gas Temperature 228
8.5 Ceiling Gas Temperature Distribution 231
8.6 One-Dimensional Simple Model 236
8.7 Summary 238
References 239
Chapter-9 241
Flame Length 241
9.1 Introduction 241
9.2 Overview of Flame Length in Open and Enclosure Fires 242
9.3 Overview of Flame Length in Tunnel Fires 244
9.4 Flame Lengths in Tunnel Fires 245
9.4.1 Transition Between Low and High Ventilation Rate 245
9.4.2 Model of Flame Length in Tunnel Fires 247
9.4.3 Flame Length with High Ventilation Rate 249
9.4.4 Flame Length Under Low Ventilation Rate 251
9.5 Summary 254
References 255
Chapter-10 257
Heat Flux and Thermal Resistance 257
10.1 Introduction 257
10.2 Convective Heat Transfer 258
10.2.1 Boundary Layer 259
10.2.2 Reynolds–Colburn Analogy 260
10.2.3 Forced Convection 262
10.2.4 Natural Convection 264
10.2.5 Gas Properties 264
10.3 Radiative Heat Transfer 265
10.3.1 Simplification in Engineering Application 266
10.3.2 View Factor 266
10.3.3 Radiation Among Multiple Surfaces 267
10.3.4 Absorbing, Emitting and Scattering Gas 268
10.4 Heat Conduction 271
10.4.1 Thermally Thin Materials 272
10.4.2 Thermally Thick Materials 273
10.4.2.1 First Boundary Condition 274
10.4.2.2 Second Boundary Condition 275
10.4.2.3 Third Boundary Condition 275
10.4.2.4 Fourth Boundary Condition 275
10.4.2.5 Complicated Boundary 276
10.5 Thermal Resistance 277
10.6 Heat Flux Measurement 278
10.7 Calculation of Heat Fluxes in Tunnel Fires 279
10.7.1 Exposed Tunnel Ceiling and Walls at Upper Layer 280
10.7.2 Heat Flux in Lower Layer 281
10.7.2.1 Horizontal and Vertical Object Surfaces 281
10.7.2.2 Inclined Target Surfaces 285
10.7.2.3 Radiation from Vertical Flames in Large Tunnel Fires 287
10.7.2.4 Verification of the Heat Flux Models in the Lower Layer 289
10.7.3 Flame Radiation in Small Tunnel Fires 291
10.8 Summary 296
References 297
Chapter-11 299
Fire Spread 299
11.1 Introduction 299
11.2 Introduction to the Theory of Ignition 300
11.2.1 Solids 300
11.2.2 Liquids 307
11.2.2.1 Release of Liquids 309
11.2.2.2 Flame Spread over a Liquid Surface 310
11.2.2.3 The Effect of Macadam 313
11.3 Fire Spread in Tunnels 313
11.4 Modeling of Fire Spread 320
11.5 Summary 325
References 325
Chapter-12 328
Smoke Stratification 328
12.1 Introduction 328
12.2 Phenomenon of Smoke Stratification 329
12.3 Mechanism of Smoke Stratification 331
12.3.1 Entrainment 332
12.3.2 Smoke Layer Height 334
12.4 Simple Model of Smoke Stratification in Tunnels 335
12.5 Summary 338
References 339
Chapter-13 340
Tunnel Fire Ventilation 340
13.1 Introduction 340
13.2 Normal Ventilation 341
13.2.1 Longitudinal Ventilation 341
13.2.2 Transverse Ventilation 343
13.2.3 Semi-transverse Ventilation 344
13.3 Longitudinal Fire Ventilation 344
13.3.1 Critical Velocity 345
13.3.1.1 Critical Froude Model 346
13.3.1.2 Non-dimensional Model 348
13.3.1.3 Influence of Vehicle Obstruction 349
13.3.1.4 Influence of Heat Release Rate in Large Fires 351
13.3.1.5 Influence of Tunnel Width 352
13.3.1.6 Critical Flame Angle 353
13.3.1.7 Short Summary 353
13.3.2 Back-Layering Length 354
13.4 Smoke Extraction 356
13.4.1 Single Point Extraction Volume 358
13.4.2 Two Point Extraction 359
13.4.3 Short Summary 360
13.5 Cross-Passages 361
13.6 Rescue Station 364
13.6.1 Configuration and Function of Rescue Station 364
13.6.2 Smoke Control 367
13.6.3 Gas Temperature Beside the Door 368
13.6.4 Fireproof Door Height 369
13.7 A Simple Model of Longitudinal Flows 369
13.8 Summary 374
References 375
Chapter-14 377
Visibility 377
14.1 Introduction 377
14.2 Different Methods of Predicting Visibility 378
14.3 The Influence of Visibility on Egress 385
14.4 Summary 389
References 389
Chapter-15 391
Tenability 391
15.1 Introduction 391
15.2 Combustion Products Related to Toxicity 392
15.3 Toxicity 393
15.3.1 Asphyxiants 393
15.3.2 Irritants 394
15.4 Fractional Effective Dose, FED 395
15.5 Fractional Effective Dose for Incapacitation 398
15.6 Large-Scale Example of Fraction of an Incapacitation Dose 402
15.7 Irritant Gas Model 404
15.8 Acceptance Criteria 405
15.9 Summary 407
References 407
Chapter-16 409
Fire Suppression and Detection in Tunnels 409
16.1 Introduction 409
16.2 Basic Concepts of Fire Suppression Systems 413
16.2.1 Deluge Water Spray System 414
16.2.1.1 General Description 414
16.2.1.2 Specific Technical Information 415
16.2.2 Water Mist Systems 418
16.2.3 Foam Systems 419
16.2.4 Mode of Operation 420
16.3 Tunnel Fire Suppression Tests 421
16.3.1 Second Benelux 2000–2001 421
16.3.2 IF Tunnel, UPTUN 2002–2004 425
16.3.3 IF Tunnel, Marioff, 2004 425
16.3.4 VSH Hagerbach, Marioff, 2005 426
16.3.5 San Pedro de Anes tests, Marioff, 2006 426
16.3.6 SINTEF Runehamar Tunnel 2007 428
16.3.7 SOLIT 2008 and SOLIT2 2012 428
16.3.8 Singapore tests 2011–2012 429
16.3.9 SP Runehamar Tunnel Fire Suppression Tests 2013 430
16.3.10 A Short Discussion 430
16.4 Theory of Fire Suppression 431
16.4.1 Extinguishment Mechanism 431
16.4.1.1 Surface Cooling 431
16.4.1.2 Gas-Phase Cooling 432
16.4.1.3 Dilution Effects and Heat Capacity 432
16.4.1.4 Radiation Attenuation 433
16.4.1.5 Kinetic and Other Factors 433
16.4.2 Critical Conditions for Extinction 433
16.4.2.1 Condensed Phase Extinction 433
16.4.2.2 Gas Phase Extinction 435
16.4.3 Fire Suppression 437
16.4.3.1 Suppression of Gas and Pool Fires 437
16.4.3.2 Suppression of Solid Fuel Fires 438
16.4.4 A Short Discussion 442
16.5 Tunnel Fire Detection 442
16.5.1 Types of Fire Detection 442
16.5.2 Summary of Fire Detection Tests in Tunnels 444
16.5.2.1 Second Benelux tunnel fire detection tests—2000/2001 444
16.5.2.2 Runehamar Tunnel Fire Detection Tests—2007 444
16.5.2.3 Viger Tunnel Fire Detection Tests—2007 446
16.5.3 A Short Discussion 446
16.6 Summary 447
References 447
Chapter-17 450
CFD Modeling of Tunnel Fires 450
17.1 Introduction 450
17.2 CFD Basics 451
17.2.1 Controlling Equations 451
17.2.2 Equation of state 453
17.2.3 Turbulence 454
17.2.3.1 Averaged Navier–Stokes models 454
17.2.3.2 Large Eddy Simulation (LES) 458
17.2.3.3 Direct Numerical Simulation 460
17.2.4 Discretization Methods 460
17.2.4.1 Temporal Discretization 461
17.2.4.2 Spatial Discretization 462
17.2.5 Solution Algorithms 463
17.3 Sub-Models Related to Tunnel Fires 463
17.3.1 Gas Phase Combustion 463
17.3.2 Condensed Phase Pyrolysis 465
17.3.2.1 Solid Phase 466
17.3.2.2 Liquid Phase 466
17.3.3 Fire Suppression 466
17.3.4 Wall Function 468
17.3.5 Heat Transfer 469
17.3.5.1 Convective Heat Transfer 469
17.3.5.2 Radiation Heat Transfer 469
17.3.5.3 Heat Conduction 471
17.4 Recommendations for CFD Users 472
17.4.1 Computation Domain and Boundary Conditions 472
17.4.2 Fire Source 472
17.4.3 Grid Size 473
17.4.4 Verification of Modeling 474
17.5 Limitations of CFD Modeling 474
17.6 Summary 475
References 476
Chapter-18 478
Scaling Technique 478
18.1 Introduction 478
18.2 Methods of Obtaining Scaling Correlations 480
18.3 Classification of Scaling Techniques 480
18.3.1 Froude Scaling 480
18.3.2 Pressure Scaling 480
18.3.3 Analog Scaling (Cold Gas, Saltwater) 481
18.4 General Froude Scaling 482
18.5 Scaling of Heat Fluxes 485
18.5.1 Scaling of Convective Heat Transfer 485
18.5.2 Scaling of Radiative Heat Transfer 487
18.5.3 Scaling of Heat Conduction 490
18.5.3.1 Thermally Thick Materials 490
18.5.3.2 Thermally Thin Materials 492
18.5.4 Scaling of Heat Balance in an Enclosure 493
18.5.4.1 Heat Loss by Convection Through Vents 493
18.5.4.2 Heat Loss by Conduction into the Walls 494
18.5.4.3 Heat Loss by Radiation Through the Vents 495
18.5.4.4 Global Heat Balance in an Enclosure Fire 496
18.6 Scaling of Water Sprays 496
18.6.1 Single Droplet 496
18.6.2 Water Sprays 498
18.6.3 Radiation Absorbed by Water Sprays 500
18.6.4 Droplet Diameter 501
18.6.5 Surface Cooling 501
18.6.6 Automatic Sprinkler 502
18.7 Scaling of Combustible Materials 503
18.8 An Example of Scaling Application in Fire Safety Engineering 504
18.9 Summary 507
References 507