Modern Energetics
Chapter 2


Turbine Plant Systems

 

Table of contents

1  Governing systems

  1.1  Introduction

  1.2  Governor characteristics

    1.2.1  Simple scheme — boiler on pressure control

    1.2.2  Turbine master load controller with boiler on pressure control

    1.2.3  Boiler master load controller

  1.3  Subsidiary functions

    1.3.1  Acceleration feedback

    1.3.2  Unloading gear

    1.3.3  Governor speed reference

    1.3.4  Closed-loop control of turbine electrical load

    1.3.5  Overspeed testing

    1.3.6  On-load testing

    1.3.7  Automatic run-up and loading systems

  1.4  Electronic governing part 1 ...2 ...3 ...4 ...5 ...6 ...7 ...8

    1.4.1  Digital processing

  1.5  Governor valve relays part 1 ...2 ...3 ...4

    1.5.1  Governor valve relay and control unit Type 1

    1.5.2  Governor valve relay and control unit Type 2

    1.5.3  Governor valve relay and control unit Type 3

    1.5.4  Reheater relief valves

  1.6  Hydraulic fluid system part 1 ...2 ...3

    1.6.1  Filtration

  1.7  Boiler feed pump turbine governors

 

2  Steam chests, valves and loop pipes

  2.1  Steam chest arrangements and construction

  2.2  Steam chest materials

  2.3  Cover seals

  2.4  Steam strainers

  2.5  Stop valves

  2.6  Governor valves

  2.7  Loop pipework

  2.8  Crossover pipework

 

3  Turbine protective devices

  3.1  Possible hazards

  3.2  Protection scheme

  3.3  Electrically-signalled trips

  3.4  Overspeed trip

  3.5  Mechanically-operated trips

  3.6  Operator tripping facilities

 

4  Turbine instrumentation

  4.1  Classification of instrumentation

    4.1.1  Supervisory instrumentation

    4.1.2  Efficiency instrumentation

    4.1.3  Auxiliary system instrumentation

    4.1.4  Condition monitoring instrumentation

    4.1.5  Instrumentation associated with protection and control equipment

    4.1.6  Instrumentation to provide post-incident records

 

5  Turbine foundations

  5.1  Tuning

  5.2  Concrete foundations

  5.3  Steel foundations

  5.4  Spring foundations

  5.5  Sub-foundation

 

6  Lubrication systems

  6.1  Lubrication requirements and typical arrangements

  6.2  Oil pumps

    6.2.1  Main lubricating oil pump

    6.2.2  Turbine-driven oil booster pump

    6.2.3  AC and DC motor-driven auxiliary oil pumps

    6.2.4  Jacking-oil pumps and priming pumps

    6.2.5  Other pumps

  6.3  Oil tanks

  6.4  Piping

  6.5  Oil coolers

  6.6  Oil strainers and filters

  6.7  Oil purifiers and coalescers

    6.7.1  Centrifugal separation systems

    6.7.2  Static oil purifiers/coalescers

  6.8  Oils and greases

    6.8.1  Oils

    6.8.2  Greases

  6.9  Jacking oil systems

  6.10  Greasing systems

 

7  Gland sealing system

  7.1  Function and system layout

    7.1.1  Labyrinth glands

    7.1.2  System layout

  7.2  Temperature and pressure control

    7.2.1  Temperature control

    7.2.2  Pressure control

  7.3  Gland steam condenser

 

8  Flange heating system

  8.1  Function and system layout

  8.2  Control

 

9  LP exhaust spray cooling system

  9.1  Function and system layout

  9.2  Control

 

10  Drains systems

  10.1  Function and system layout

    10.1.1  Start-up drains

    10.1.2  Continuous drains

  10.2  Control

 

11  By-pass systems

  11.1  Configuration

    11.1.1  Pressure control valves

    11.1.2  Isolating valves

    11.1.3  Dump tube

  11.2  By-pass systems for nuclear plant

  11.3  By-pass systems for fossil-fired plant

  11.4  Problems with by-pass systems

    11.4.1  Noise

    11.4.2  Water ingress

    11.4.3  Thermal shock

    11.4.4  Leakage flows

 

12  Operational flexibility

  12.1  Typical operational regimes

    12.1.1  Base load

    12.1.2  Two-shifting

    12.1.3  Load cycling

  12.2  Influence on machine design

    12.2.1  Turbine cylinders

    12.2.2  Turbine rotors

    12.2.3  Stress monitors

  12.3  Forced-air cooling

    12.3.1  Cooling of turbine

    12.3.2  Cooling system

 

13  Wet steam turbine plant

  13.1  Influence of steam on components part 1 ...2 ...3

  13.2  Water extraction devices

  13.3  Erosion protection

  13.4  Moisture separator reheaters (MSRs)

    13.4.1  Separators part 1 ...2 ...3 ...4

    13.4.2  Steam-to-steam reheaters part 1 ...2 ...3 ...4 ...5 ...6 ...7

  13.5  Steam supply and drains systems

    13.5.1  First-stage reheat

    13.5.2  Second-stage reheat

    13.5.3  Performance monitoring

    13.5.4  System drains

    13.5.5  Separator drains

    13.5.6  Reheater drains

 

14  References