Page 9 - Steam Turbines Design, Applications, and Rerating

viii Contents

Chapter 4. Rotors for Impulse Turbines 81
4.1 Long-Term Operating Experience 81
4.2 Pitch Diameter and Speed 82
4.3 Steam Temperature 83
4.4 Built-Up Construction 84
4.5 Solid Construction 89
4.6 Shaft Ends 90
4.7 Turbine Rotor Balance Methods 91
4.7.1 At-speed rotor balancing 92
4.8 Balance Tolerance 94

Chapter 5. Rotors for Reaction Turbines 95
5.1 Solid Rotors 95
5.2 Materials for Solid Rotors 99
5.3 Welded Rotor Design 100
5.4 Welded Rotor Materials 105

Chapter 6. Turbine Blade Design Overview 109
6.1 Blade Materials 111
6.2 Blade Root Attachments 111
6.3 Types of Airfoils and Blading Capabilities 113
6.4 Guide Blades for Reaction Turbines 114
6.5 Low-Pressure Final Stage Blading 120

Chapter 7. Turbine Auxiliaries 125
7.1 Lube Systems 125
7.2 Barring or Turning Gears 128
7.3 Trip-Throttle or Main Stop Valves 129
7.4 Overspeed Trip Devices 132
7.5 Gland Seal Systems 135
7.6 Lube Oil Purifiers 135
Chapter 8. Governors and Control Systems 137
8.1 General 137
8.2 Governor System Terminology 140
8.2.1 Speed regulation 140
8.2.2 Speed variation 141
8.2.3 Dead band 141
8.2.4 Stability 141
8.2.5 Speed rise 141
8.3 NEMA Classifications 143
8.4 Valves 144
8.4.1 Single-valve turbines 144
8.4.2 Multivalve turbines 145
8.5 PG Governors 145
8.6 Electronic Governors 148
8.7 Governor Systems 150
8.7.1 General 150
8.7.2 Extraction control 150