Page 11 - Steam Turbines Design, Applications, and Rerating

x Contents

12.3 Efficiency 220
12.4 Design 223
12.4.1 Rotor 223
12.4.2 Blading 224
12.5 Erosion 230
12.6 Axial Thrust 232
12.7 Maintenance 233
12.8 Design Features of Modern Reaction Turbines 233
12.9 Deposit Formation and Turbine Water Washing 235

Chapter 13. Transmission Elements for High-Speed Turbomachinery 243
13.1 Spur Gear Units 243
13.2 Epicyclic Gears 245
13.3 Clutches 246
13.4 Hydroviscous Drives 253
13.5 Hydrodynamic Converters and Geared Variable-Speed Turbo Couplings 257
13.5.1 Function of the multistage variable-speed drive 261
13.5.2 Design and operating details 261
13.5.3 Working oil and lube oil circuits 264
13.5.4 Lubricating system 264
13.5.5 Lubricant oil containment on gear and variable-speed units 265

Chapter 14. Shortcut Graphical Methods of Turbine Selection 267
14.1 Mollier Chart Instructions 267
14.2 Estimating Steam Rates 271
14.3 Quick Reference Information to Estimate Steam Rates of Multivalve,
Multistage Steam Turbines 303

Chapter 15. Elliott Shortcut Selection Method for Multivalve,
Multistage Steam Turbines 309
15.1 Approximate Steam Rates 309
15.2 Stage Performance Determination 313
15.3 Extraction Turbine Performance 320

Chapter 16. Rerates, Upgrades, and Modifications 329
16.1 Performance and Efficiency Upgrade 331
16.1.1 Brush seals and labyrinth seals 332
16.1.2 Wavy face dry seals 336
16.1.3 Buckets 348
16.2 Reliability Upgrade 352
16.2.1 Electronic controls 352
16.2.2 Monitoring systems 356
16.3 Life Extension 356
16.4 Modification and Reapplication 358
16.4.1 Casing 359
16.4.2 Flange sizing 360
16.4.3 Nozzle ring capacity 362
16.4.4 Steam path analysis 362