EMERSON Process Management

1. Power Plant ApplicationsPower Plant Applications
Nigam SharmaNigam Sharma
Sr. Regional Manager, Asia PacificSr. Regional Manager, Asia Pacific

2. AgendaAgenda
 Power Plants Over View
 Main Components of a Power Plant
 Typical Controls Applications

3. Types of PlantsTypes of Plants
 Thermal Power Plants
 Coal Fired Utility
 Oil and Gas Fired Plants
 Bio-fuel Plants
 Gas Turbine Plants
 Gas and Oil Fired
 Simple Cycle Gas Turbine Plants
 Combined Cycle HRSG and Steam Turbine Plants (CCP)
 Cogeneration Plants (Industrial or District Heating)
 Oil & Gas Fired CCP
 Bio-Fuel CFB plants
 Nuclear Plants
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4. Thermal Plant OverviewThermal Plant Overview
1. Cooling Tower 2. Cooling Water Pump 3. 3-phase Transmission Line
4. Unit Transformer 5. 3-phase Electric Generator 6. Low Pressure Turbine
7. Boiler Feed Pump 8. Condensor 9. Intermediate Pressure Turbine
10. Steam governor valve 11. High Pressure Turbine 12. Deaerator
13. Feed Water Heater 14. Coal Conveyor 15. Coal Hopper
16. Pulverised Fuel Mill 17. Boiler Drum 18. Ash Hopper
19. Superheater 20. Forced Draught Fan 21. Reheater
22. Air Intake 23. Economiser 24. Air Preheater
25. Electrostatic Precipitator 26. Induced Draught Fan 27. Chimney Stack

5.  Boilers or Steam Generators
 Generate steam at desired rate, pressure and temperature by
burning fuel in its furnace.
 The boiler is that part of the steam generator where phase change
(or boiling) occurs from liquid (water) to vapour (steam), essentially
at constant pressure and temperature.
 Steam Turbine
 Steam turbine is a mechanical device that extracts thermal energy
from pressurized steam, and converts it into useful kinetic
(rotational) energy which rotates the steam turbine.
 Most steam turbines rotate at 3000 rpm or 3600 rpm.
 Electric Generator
 Electrical generator is a device that converts kinetic energy to
electrical energy, generally using electromagnetic induction.
 Electric Generators are rotated by Steam Turbines at 3000 rpm or
3600 rpm
Major ComponentsMajor Components

6. Bottom
Ash
System
Economizer
Hoppers
F D
FanGeneral
Water
Sump
BOTTOM
ASH
HOPPER
Settling
Pond
WATER
TREATMENT
Coal
Bunker
Conveyors
Pulverizers
Load
Gen.HP IP L P
Turbine
Econ-
omizer
Re-
Heat
Super
Heater
DRUM
Condenser
P A
Fan
ID
Fans
HP
FW
Htr
LP
FW
Htr
Ash
Transfer
Water
Clean-up
Precipitators
Stack
Gas
Scrubber
Emissions
Monitor
Flyash
Cond.
Pump
BFP
Deaerator
Cooling
Water
Feeder
Downcomers
Risers
Air Heater
Power Plant Process MapPower Plant Process Map
Water Vapor &
Scrubbed Gases

7. Basic Boiler TypesBasic Boiler Types
 Up to an operating pressure of around 190Kg Bar in the
evaporator part of the boiler, the cycle is Sub-Critical. In this case
a drum-type boiler is used because the steam needs to be
separated from water in the drum of the boiler before it is
superheated and led into the turbine.
 Above an operating pressure of 220Kg Bar in the evaporator part
of the Boiler, the cycle is Supercritical. The cycle medium is a
single phase fluid with homogeneous properties and there is no
need to separate steam from water in a drum. Drumless or Once-
through boilers are therefore used in supercritical cycles.
 Advanced Steel types must be used in Supercritical boilers for
components such as the boiler and the live steam and hot reheat
steam piping that are in direct contact with steam under elevated
conditions
 Sub-critical Boilers: Steam conditions up to 220Kg bas/ 540°C
are achieved
 Supercritical Boilers: Steam conditions up to 300 Kg
Bar/600°C/620°C are achieved using steels with 12 % chromium
content.

8. Supercritical Once Through Power PlantSupercritical Once Through Power Plant
 Power Generation Cycle Efficiency primarily depends on the
temperature difference across steam turbine.
 Higher boiler outlet temperature results in higher difference.
 Higher steam temperatures is also linked to increased pressures
to keep the steam volume within manageable limits.
 At pressures in excess of 220Kg bar, the fluid is termed
supercritical.
 The increased pressure also increases cycle efficiency and,
although this increase is a second-order effect compared with the
effect of temperature, but it can still make an important
contribution to increasing overall plant efficiency.
 “SupercriticalSupercritical" is a thermodynamic expression describing the
state of a substance where there is no clear distinction between
the liquid and the gaseous phase (i.e. they are a homogenous
fluid). Water reaches this state at a pressure above around 220
Kg Bar.

9. Supercritical Once Through Power PlantSupercritical Once Through Power Plant
 Supercritical coal fired power plants have higher efficiencies
of almost 45%
 Supercritical Power plants have lower emissions than sub-
critical plants at any given power output.

10. Various Boiler TypesVarious Boiler Types

11. HP
FW
HTR
LP
FW
HTR
HP L PSecondary
Super
Heater
Power Plant ProcessPower Plant Process
MapMap
Once-Thru Boiler
BFP
Water Vapor &
Scrubbed Gases
Load
Gen.
Turbine
Econ-
omizer
Re-
Heat
Condenser
ID
Fan
Precipitators
Stack
Gas
Scrubber
Emissions
Monitor
Flyash
Deaerator
Cooling
Water
Bottom
Ash
System
Economizer
Hoppers
F D
Fan
Settling
Pond
Ash
Transfer
Water
Clean-up
Cond.
Pump
General
Water
Sump
Coal
Bunker
Conveyors
Pulverizers
P A
Fan
Feeder
Primary
Super
Heater
IP
Air Heater
BOTTOM
ASH
HOPPER

12. Circulating Fluidized Bed BoilersCirculating Fluidized Bed Boilers
 A bed of sand, ash and fuel particles
is fluidized by the combustion air,
which is blown into the bed through
the bottom.
 Due to high air/flue gas velocity the
fuel is carried over in the combustion
gases.
 The solid material is then separated in
a cyclone and recycled to the lower
section of the bed.
 CFB combustion process is ideally
suited to burning
 low-quality fuels,
 fuels with a high moisture content
 'waste-type' fuels.
 All coals, lignite, petroleum coke,
biomass, waste coal, refuse-derived
fuels, agricultural and pulping waste,
and municipal solid waste

14. Typical Large Steam TurbineTypical Large Steam Turbine
 Steam turbine is a mechanical device that extracts thermal energy from
pressurized steam, and converts it into useful kinetic (rotational)
energy by expansion.
 The expansion takes place through a series of fixed blades (nozzles)
and moving blades.
 The moving blades rotate on the turbine rotor and the fixed blades are
concentrically arranged within the circular turbine casing which is
substantially designed to withstand the steam pressure.
 Most steam turbines rotate at 3000 rpm or 3600 rpm.

15. Basic Steam TurbinesBasic Steam Turbines
 The Turbine designs for a Supercritical plant are similar to the
sub-critical except that special materials required for the casings
and walls for withstanding high Temperatures and pressures in
Supercritical Steam Turbines.
 High Pressure (HP) Turbine: In order to cater for the higher
steam parameters in supercritical cycles, materials with an
elevated chromium content which yield higher material strength
are selected.
 Intermediate Pressure (IP) Turbine Section: In supercritical
cycles there is a trend to increase the temperature of the reheat
steam that enters the IP turbine section in order to raise the
cycle efficiency. As long as the reheat temperature is kept at
560 DEGC there is not much difference in the IP section of Sub
critical and Super Critical plants.
 Low Pressure (LP) Turbine Section: The LP turbine sections
in supercritical plants are not different from those in subcritical
plants.

16. Combined Cycle PlantsCombined Cycle Plants
 Term Combined Cycle is used to describe process that uses
combination of more than one thermodynamic cycles.
 Combined Cycle Power Plant (CCPP) means a combination of
gas turbine generator (Brayton cycle) with turbine exhaust
waste heat boiler and steam turbine generator (Rankine cycle)
for the production of electric power.
 CCPP Common Combinations
 One CT and One Steam Turbine (1 on 1)
 Two CTs and One Steam Turbine (2 on 1)
 X CTs and Y STs (X on Y)
 CTs always paired with a HRSG
 2 on 1 common - all generators work out to be comparable size

17. Simple Cycle Combustion (Gas) TurbineSimple Cycle Combustion (Gas) Turbine
Thermal Efficiency = 35-40%
35-40% Electricity
Generator
3% Aux. Power + Losses
Air
100% Fuel
Combuster
Stack
57-62%
Compressor Turbine

18. Combined Cycle Power GenerationCombined Cycle Power Generation
Thermal Efficiency = 45-55%
35-40% Electricity
Generator
6% Aux. Power + Losses
Air
100% Fuel
Combuster
Stack
20%
Compressor Turbine
28%Steam Condenser
HRSG
Steam
Supplementary
Fuel (Optional)
Exhaust
Gas
Steam TurbineGenerator
12-15% Electricity
Lake

19. Typical Combined Cycle PlantTypical Combined Cycle Plant
Gas Supply Station
Gas Supply Gas Turbine Stack
Heat Recovery Steam Generator
HRSG Stack
Generator
Transformer
Transmission
Deaerator
Boiler Feed Pump
Cooling
Towers
Condensate
Extraction Pump
Generator
Transformer Transmission
Gas Turbine
IP LP Generator
Cooling Water
Switch Yard
Demineralization Plant
Raw Water
FW
FW
Switch Yard
Air Intake
Condenser
Bypass
Damper

20. Most Common Combined CycleMost Common Combined Cycle
– 2 on 1 Process– 2 on 1 Process
Air
Air
GT
GT
HRSG
HRSG
ST
Gen
Gen
Gen
Steam
Steam
Stack Gas
Stack Gas
Legend
GT – Gas Turbine Gen - Generator
ST – Steam Turbine HRSG – Heat Recovery Steam Generator

21. Common Cogeneration PlantsCommon Cogeneration Plants
 Cogeneration is the simultaneous production of power/electricity,
hot water, and/or steam from one fuel.
 Cogeneration plants can reach system efficiencies exceeding 80%
 Industrial Plants
 Multi utility plants; Electricity, Process Steam, Heating Steam, Hot
water, Chillers etc.
 District Heating Plants
 Extraction steam for residential heating
 Oil or Gas fired
 Combined Cycle Cogen
 Conventional Boilers Cogen
 Circulating Fluidized Bed Boilers
Low Calorific Value, high moisture, low Sulphur fuels
Bagasse, Rice husk, Rice Straw, Wood Chips etc

22. Industrial Co-GenerationIndustrial Co-Generation
Bagasse
Rice Husk
Rice Straw
Wood Chips
Etc.
Thermal Efficiency = 80%

23. District HeatingDistrict Heating
15%
Steam
Stack
Air
15% Electricity
Boiler Steam Turbine Generator
5% Aux. Power + Losses
Heat
Exchanger
55%
Steam
Condenser
10% Losses
Feedwater
Loop
Thermal Efficiency = 70%

24. Power Plants ControlsPower Plants Controls
CapabilityCapability

25. Typical Boiler Plant Control FunctionsTypical Boiler Plant Control Functions
 Fuel Management
 Fuel control
 Mill control
 Burner Safety & control
 Air Management
 Fans Control
 Steam temperature Management
 SH Steam Temp Control
 RH Steam Tem Control
 Feed Water Management
 Boiler Drum Level Control
 Deaerator Level Control
 Soot Blower Controls
 Emission Management

26. Typical Steam Turbine Control FunctionsTypical Steam Turbine Control Functions
 Speed loop Control
 MW loop Control
 Speed or MW demand and rate
selections
 Initial MW pickup
 1st stage pressure loop
 Load limiting
 Inlet pressure limiting
(adjustable)
 Fail safe turbine trip design
 Valve testing & Valve
calibration
 Individual valve curves
 Critical Overspeed detection &
protection
 Hotwell Level & Condensate
extraction Controls
 HP & LP Bypass Controls
 HP & LP Heater level Cascade
Controls
 Gland steam Press control
 Turbine Stress Calculations
 Turning Gear Controls
 Main Oil, Safety Oil Pumps Control
 Seal Oil Pumps
 Extraction controls

27. Typical CCPP Control FunctionsTypical CCPP Control Functions
 HRSG (Heat Recovery Steam Generator) Boiler Controls
 Un-fired HRSG
Bypass Damper Control
Feedwater - Drum Level Control
Live Steam Temperature Control
Turbine Bypass Control
Deaerator Level Control
Hotwell Level Control
Advanced Controls
 Fired HRSG (additional controls)
Fuel Controls
Air Control
Burner Management
Temperature Control
 Gas Turbine Controls
 In most cases GT controls are supplied by OEM

28. Typical Balance of Plant ControlsTypical Balance of Plant Controls
 Balance of Plant Controls (Miscellaneous Controls)
 Water Treatment Plant Controls
 Circulating Water System
 Raw Water system
 Turbine Cooling Oil Temperature Controls
 Generator Cooling Oil Temperature Controls
 Ash Handling System Controls
 Fuel Handling Systems
Fuel Skid Controls (CCPP)
Coal Handling System Controls
 Environmental Controls
Flue Gas De-Sulphurization Controls
Scrubber Controls
 Motor Controls
 Electrical Controls & Monitoring

29. Basic level:
 Single drive control with electrical protections, auto/manual modes
 Single loop control with protection of actuators, auto/manual modes
 Interlocks between the control loops and drives
Control of technological groups for Boiler and Turbine:
 Coordinated loops control (common setpoint, interactions)
 Cross interlock feedbacks and priorities
 Sequences
 Turbine start-up, roll-off, and other turbine coordinated controls
 Burner Management System
Coordinated Unit Control:
 LDC - Load Demand Computer - selection of boiler / turbine modes
 Unit remote control from Dispatch Center
 Main unit control sequences
 Run-backs & Run-ups
Concept of a Unit ControlConcept of a Unit Control

30. Binary Control
Drive Control Standards for:
 low voltage motors
 high voltage motors
 open/close valves or dampers
 electrical actuators
Sequential Control
Features of a sequence:
 consists of a sequence head and sequence steps
 sets time relations between performed steps
 allows start, stop and resume by operator
 incorporates emergency logic and procedures
 incorporates interaction logic and operator’s permissives
Concept of a Unit ControlConcept of a Unit Control

31. Modulating Control
 Control Structures:
 Basic level - single loop executing a direct control of actuator
 Cascade level calculating setpoint for basic level loop
 Coordinating level responsible for unit load and cross feedbacks
between parts of the unit
 Supervisory optimization structure, which calculates corrections for
other control loops, based on feed-forward and Smith prediction
philosophy
 Control Algorithms:
 Mathematical algorithms
 Universal PID type (PID, PIDFF)
 Dedicated for power applications: Smith predictor, drum level
correction, steam table, PID with variable parameters
 Value tracking for bumpless transfer during auto / manual switch
 Advanced algorithms
Concept of a Unit ControlConcept of a Unit Control

32. Coordinated Unit ControlsCoordinated Unit Controls

33. Coordinated Unit ControlsCoordinated Unit Controls
ADS
Interface
Unit
Master
Boiler
Master
Fuel
Master
Air
Steam
Temp Feedwater
Boiler Turbine
Turbine
Master
Mill 1 Mill n
ID
Fans
FD
Fans
Furnace Draft
S-heat
Spray
R-heat
Spray
BF-
Pump
Turbine
Valves
Load Demand

34. Front End
Front End SystemFront End System
ADS
Interface
Unit
Master
Boiler
Master
Fuel
Master
Air
Steam
Temp Feedwater
Boiler Turbine
Turbine
Master
Mill 1 Mill n
ID
Fans
FD
Fans
Furnace Draft
S-heat
Spray
R-heat
Spray
BF-
Pump
Turbine
Valves
Load Demand

35. ADS
Interface
Fuel
Master
Air
Steam
Temp
Feedwater
Boiler
Turbine
Front End
Mill 1 Mill n
ID
Fans
FD
Fans
Furnace Draft
S-heat
Spray
R-heat
Spray
BF-
Pump
Turbine
Valves
Load Demand
Load Demand Computer
(LDC)
Load Demand ComputerLoad Demand Computer

36.  Invented by Westinghouse for coordinated unit control
 Allows to control a unit in different modes of operation:
 Turbine Follow Mode: Turbine control with throttle pressure –
The turbine follows the boiler load, LDC tracks the actual unit load and
calculates setpoint for the boiler (MW loop is not in use)
 Boiler Follow Mode: Boiler control with live steam pressure –
The boiler adapts the steam generation to the consumption required by
the turbine, LDC tracks the actual unit load and calculates the setpoint
for turbine valve position (MW loop is not in use)
 Coordinated Control Mode:
Either turbine or boiler controls live steam pressure and boiler or turbine
respectively (MW loop is in use for turbine or boiler)
Load Demand ComputerLoad Demand Computer

37.  LDC is a software model of the process, which calculates
on-line all required control setpoints using “feed-forward”
 Operator sets the required load or MW demand
 LDC calculates the main setpoints separately for the boiler
and the turbine control structures
 The structure for boiler recalculates setpoints for loops
controlling air and fuel
 Tunable function generator algorithms calculate setpoints for
loops controlling the actuators
 LDC allows to keep unit in automatic control also during
runbacks or trips
Load Demand ComputerLoad Demand Computer

38.  Four Modes
 Coordinated
 Turbine Follow
 Boiler Follow
 Manual (separated)
 Bumpless transfer between all modes
 Interlocks prevent Unit Master from controlling unless either
Boiler or Turbine Master in Auto
 Rate limiting on ramped signals
Load Demand ComputerLoad Demand Computer

40.  Turbine Master (Fixed Pressure)
 regulates turbine to satisfy megawatt demand
 Recognizes boiler’s response capabilities
Turbine MasterTurbine Master

41.  Turbine Master (Variable or Sliding Pressure)
 Alternative to fixed pressure mode
 Throttle pressure varied with load while turbine valves
remain in fixed position
 Valves allowed to move on load changes for fast
response
 Throttle pressure allowed to vary to maintain proper
valve position
 Not suitable for all boilers
Turbine MasterTurbine Master

42.  Boiler Master
 Sets boiler firing rate
 Interlocked to lower control loops
 Dynamic control to improve responsiveness
 Runbacks and rundowns based on boiler capabilities
Boiler MasterBoiler Master

43. ADS
Interface
LDC
Boiler
Master
Fuel
Master
Air
Steam
Temp
Feedwater
Boiler Turbine
Turbine
Master
Mill 1 Mill n
ID
Fans
FD
Fans
Furnace
Draft
S-heat
Spray
R-heat
Spray
BF-
Pump
Turbine
Valves
Load Demand
Fuel MasterFuel Master

44. FuelFuel
MasterMaster
 Fuel Master
 Develops base control signal for coal mills
 Performs fuel/air cross limiting
 Incorporates a mill model to improve coal flow
measurement
 Uses boiler as calorimeter

45. FuelFuel
MasterMaster
 Mill Controls
 Regulates coal flow
 Regulates primary air flow
 Regulates coal/air temperature leaving mill
 Feeder overrides on high mill amps and/or mill differential
pressure
 Primary air flow takes priority over coal/air temp.
 Includes interlocks to air dampers for safety and interface
to BMS

46. ADS
Interface
LDC
Boiler
Master
Fuel
Master
Air
Steam
Temp
Feedwater
Boiler Turbine
Turbine
Master
Mill 1 Mill n
ID
Fans
FD
Fans
Furnace
Draft
S-heat
Spray
R-heat
Spray
BF-
Pump
Turbine
Valves
Load Demand

47. Air FlowAir Flow
ControlControl
 FD Fan Control
 Controls combustion air flow
 Firing rate sets air flow
requirement
 Includes damper interlocks
 Interlocked to ID fans for auto
mode
 Includes fuel/air cross limiting
(O2 trimming)

48. Air FlowAir Flow
ControlControl
 Furnace Draft Control
 Regulates ID fans to provide proper exhausting force for gas flow
through boiler
 Uses FD fan demand as feedforward
 Utilizes three furnace pressure transmitters (middle-of-three) for
control
 Fully meets NFPA requirements for:
Rapid closing of ID inlet dampers on MFT
Directional blocking on low furnace pressure
 Includes damper interlocks for starting/stopping

49. ADS
Interface
LDC
Boiler
Master
Fuel
Master
Air
Steam
Temp
Feedwater
Boiler Turbine
Turbine
Master
Mill 1 Mill n
ID
Fans
FD
Fans
Furnace
Draft
S-heat
Spray
R-heat
Spray
BF-
Pump
Turbine
Valves
Load Demand

50. FeedwaterFeedwater
ControlControl
 Feedwater Control
 Regulates feedwater flow and
controls drum level
 Two modes of operation
Single element for use
during startup
Three element for
normal operation
 Drum level signals are
density compensated

51. Drum levelDrum level
ControlControl

52. ADS
Interface
LDC
Boiler
Master
Fuel
Master
Air
Steam
Temp
Feedwater
Boiler Turbine
Turbine
Master
Mill 1 Mill n
ID
Fans
FD
Fans
Furnace
Draft
S-heat
Spray
R-heat
Spray
BF-
Pump
Turbine
Valves
Load Demand

53. SteamSteam
TemperatureTemperature
 Superheat Temperature Control
 Regulates main steam temperature
 Standard consists of two stage attemperation
 Includes integral windup protection
 Includes interlocks for spray and block valves

54. SteamSteam
TemperatureTemperature
 Reheat Temperature Control
 Regulates reheat steam temperature thru the use of sprays &
burner tilting arrangement
 System tracks until spray valve open
 Interlocks for both spray and block valves included

55. Furnace 2 nd
S.H.
PID
PID
PID
PID
X
Firing Rate
Boiler
Master
Desired Spray
(20%)
WW Outlet
Temp
LDC
Out
Econo
mizer
Fuel/Air
4th
S.H.
3rd
S.H.
PID
FW Flow
Control
FW/FR
ratio
DMC
Algorithm
SUM
RH
Tilts/Damper
Setpoints
2nd
, 3rd
and 4th
SH
1st
S.H.
APC Steam Temperature ControlAPC Steam Temperature Control
SchemeScheme

56.  A Safety System
 Permits safe start-up, operation, and shutdown of the boiler
 Supervises Fuel insertion/withdrawal from boiler conforming to
established safety standards
 Monitors and controls igniters and burners
 Separate Flame Scanners used to detect igniter and main flames
 Three type of flame scanners
 Ultraviolet, typically used for natural gas and light oils
 Infrared, typically used for medium to heavy oils and pulverized coal
 All Fuels, typically used with gas igniters & coal as main fuel
 Other Field Devices
 Safety shut-off valves
 Pressure, temperature, flow & valve position limit switches
 Blowers to cool scanners or provide combustion air for igniters
Burner Management SystemBurner Management System
DefinitionDefinition

57.  Critical safety signals are wired as redundant I/O for maximum boiler
safety.
 An automatic start sequence ensures correct completion of boiler air
purge and satisfies safety permissives before fuel firing, preventing
operator error.
 Continued monitoring of boiler conditions actuates a safety shutdown trip
if unsafe conditions develop.
 Operator maintains control capabilities from the operator console or
burner front digital logic stations.
 First-out indications are provided for identification of the cause of boiler
trip
 Automatic Boiler Purge Prior to Restart
 Flame Detection, Monitoring & protection
 Master Fuel Trip
 Burner/Mill Start-Up and Shutdown
 Sequences
 Safety Interlocking
 Alarming of Abnormal Conditions
Burner Management SystemBurner Management System

58.  6 to 8 Pulverizers (Mills) needed in each boiler to supply
Pulverized coal to the burners
 One mill normally supplies pulverized coal to one burner
level. Additional mills supply each additional burner level
on a one-for-one basis.
 There are between four and eight burners per level. This
depends upon the type of furnace, e.g. wall fired,
tangential, split furnace, etc.
 With dual fuel firing, there will also be oil guns /gas nozzles
on one or more burner levels. There will be four to eight
guns / nozzles per level.
Mills, Burners and LevelsMills, Burners and Levels

59. Burner ArrangementsBurner Arrangements
Wall-Fired Tangential Corner-Fired
Slag
Crushed Coal
Air Secondary
Furnace
Primary Furnace
Cyclone
(B&W Exclusive)

60. Burner ArrangementsBurner Arrangements
Multiple
Elevations
To other
burners
this elevation
Drive
Motor
Pulvorizer
or ‘Mill’
Feeder
Coal
Bunker
Air in
Boiler
One of six;
one per burner
elevation

61. The Burner "Front"The Burner "Front"
Startup Sequence
(Light-off by burner pairs)
- Purge air-10 Minutes
- Purge air Off
- Open Dampers
- Ignition Spark ON
- Ignition Valve OPEN
- Prove Igniter ON
- Main Fuel ON
- Prove Main Flame ON
- All Ignition OFF on
Combustion Control
Fuel
Ignition
Transformer
Igniter
Damper
Damper
Purge
Air
Main Burner
Ignition
Flame
Main
Flame
Ignition
Flame
Det.
Main
Flame
Det
Cooling
Air
Wind
Box

62.  Enhanced safety and availability
 Greater operational flexibility
 Significant auxiliary fuel savings
 Continuous safety monitoring
 Consistent start-up and operation
 Full integration of all facets of the firing system
 Integrated Air damper controls
 Improved plant availability
 Reduced maintenance costs
 Prevention of boiler explosion
 NFPA 8502 code compliance
 Expandable solutions
Ovation BMS FeaturesOvation BMS Features

63. Turbine
Master
Boiler
Master
Feedwater Combustion
Fuel
Valve
FD Fan ID Fan
Pump
(Turbine)
Pump
(Shaft)
Pump
(Standby)
Load Demand
Computer
High Limit
Low Limit
Ramp Rate
Operator
Set Limits
Runbacks
Rundowns
Block Increase
Block Decrease
Contingency
Digital
Control
LocalRemote
Valve
Positioner
Pass
Dampers
Spray
Steam
Temp.
Steam Turbine ControlsSteam Turbine Controls

64. Ovation Turbine Control ArchitectureOvation Turbine Control Architecture
 Redundant systems
 - Processor - I/O interface
 - Power supplies - Network
interface
 System same as rest of plant
 Controller hardware and I/O
 User Interfaces
 Network
 Standard I/O cards for specialized
turbine applications
 Speed cards
 Valve cards

65. Turbine Control Requires Specialized I/OTurbine Control Requires Specialized I/O
 Speed Detector Module
 Valve Positioner Module
 Servo Driver Module

66. Speed Detector ModuleSpeed Detector Module
 5ms update rate for overspeed
detection
 Variable update rate for speed
regulation
 Controller-independent speed detection
and tripping using dual on-board form
C outputs for fast reaction to over
speed conditions
 Open-wire detection for low resistance
source less than 5000 Ohms
 Redundant power feeds
 1000V dielectric withstand electrical
isolation between logic signal and field
inputs
 Hot swap capability

67.  Self calibrating & Self Diagnostics
 PI control loop with 10 millisecond loop time
 Programmable PI gain and integral time constants
 Normal mode or SLIM interface for local manual operation
 Up to three redundant servo valve actuator coil drive outputs
 Supports redundant coil and redundant LVDT capability (Redundant configuration)
 Interfaces to LVDT interface to primary excitation and dual secondary feedback
windings
 24/48V dc input for emergency valve closure independent of controller
 16 bit micro-controller watchdog timer for servo valve actuator coil drive
 Supports single mode (full arc) or sequential (partial arc) modes of valve operation
 Watchdog timer for I/O bus
 Redundant configuration option
 Redundant 24V power auctioneering
 Local calibration & tuning capability without trim pots
 Open-coil and shorted-coil diagnostics
 Runs seating and back-seating logic
Valve Positioner ModuleValve Positioner Module

68.  Self calibrating & Self Diagnostics
 PI control loop with 10 millisecond loop time
 Programmable PI gain and integral time constants
 Normal mode operation only 2 servo valve actuator coil drive outputs
 Supports redundant coil and dual LVDT capability.
 2 DC-LVDT or AC-LVT outputs & 2 DC-LVDT or AC-LVT inputs
 16 bit micro-controller
 Watchdog timer for servo valve actuator coil drive
 Watchdog timer for I/O bus
 Redundant feedback option for AC-LVT
 Redundant 24V power auctioneering
 Local calibration & tuning capability without trim pots
 Open-coil and shorted-coil diagnostics
 Runs seating and back seating logic
 Hot swap capability
Servo Driver ModuleServo Driver Module

69.  Main Stop Valves or Throttle Valves, used primarily during
start-up, machine protection
 Governor Valves or Control Valves, control the turbine over
most of the operating range
 Reheat Stop Valve, on-off type valve to backup the
intercept valve
 Intercept Valve, used to prevent steam from entering
turbine after load loss
 Full Arc Admission / Partial Arc Admission
 Single Valve Mode / Sequential Valve Mode
Steam Turbine Valve TerminologySteam Turbine Valve Terminology

70. Governor Control FunctionsGovernor Control Functions
 Control of:
 Turbine stop valves
 Control valves
 Reheat stop valves
 Intercept valves
 Monitor & Control of:
 Speed
 Main steam pressure
 Chest pressure
 1st stage pressure
 Reheat pressure
 Load

71. Typical Large SteamTypical Large Steam
TurbineTurbine
HP
TURBINE
IP
TURBINE
LP
TURBINE
SPEED
SENSING
CONTROL
SYSTEM
CONTROL
INPUT
STEAM
GEN
INTERCEPT
VALVE(S)
REHEAT STOP
VALVE(S)
REHEAT
AND/OR
MOISTURE
SEPARATOR
CONDENSER
(W) GOVERNOR/
(GE) CONTROL
VALVE(S)
(W) THROTTLE/
(GE) STOP
VALVE(S)
CROSSOVER
GENERATOR
GENERATOR
BREAKER

72. 1
3
5
2
6
3
5
1
2
4
6
4
Main Steam Supply
Governor/
Control
Valves
Governor/
Control
Valves
Throttle/
Stop
Valve 1
Throttle/
Stop
Valve 2
Nozzle
Block
Full Arc / Single Valve Mode = All Governor/Control Valves opened together
Partial Arc / Sequential Valve Mode = Governor/Control Valves opened independently
Steam Flow Through Nozzle BlockSteam Flow Through Nozzle Block

73. Typical Startup and Loading ProgramsTypical Startup and Loading Programs
 Pre Warm
 Pre Roll Conditions
 1st Stage Shell Metal Temp Change
 Hot Reheat Temp Change
 HP allowable Ramp Rate
 Reheat allowable Ramp Rate
 1st Stage Shell Steam Temp
 Speed Soaks (1000, 3000 and 3600 RPMs)
 Initial Load Pickup and Soak

74. Steam Turbine System AuxiliariesSteam Turbine System Auxiliaries
 Motor Operated Valves
 Solenoid Operated Valves
 Vapor Extractors
 Turning Gear
 Turbine Drain Valves
 Jacking Oil Pumps
 Gland Steam System
 Seal Steam System
 Lube Oil System
 Auxiliary Steam System
 Emergency Leak-off System
 Vacuum Breakers
 Bentley Nevada Modbus Link
 Turbine Supervisory

76.  Turbine bypass systems can contribute to flexible plant
operation mainly by supporting:
 Repeatedly attainable fast startups with the greatest possible regard
to the lifetime of heavy-walled components.
 Quickest possible restoration of power supply to the grid after any
disturbance
 Saves startup time by avoiding boiler trip on turbine trip.
 Ensures high reliability and availability of the plant
 Bypass systems contribute to the overall target of safe and
efficient supply of electric power at minimum total cost.
 Steam bypass systems bring substantial fuel savings while
they solve many of the problems caused by using baseload
generating units for cyclic operation
Turbine Bypass SystemTurbine Bypass System

77.  The steam bypass system is generally used during the
following modes of operation:
 Start-up and shutdown,
 Steam turbine trip,
 Steam turbine no-load or low-load operation
 Fast Run back
 Fast load throw off
 House load operation
Turbine Bypass SystemTurbine Bypass System

78. Turbine Bypass System for Thermal PlantTurbine Bypass System for Thermal Plant

79. Turbine Bypass System for CCP PlantTurbine Bypass System for CCP Plant

80. Typical Large Steam TurbineTypical Large Steam Turbine
Extraction Steam and Heater SystemsExtraction Steam and Heater Systems
I P
Turbine
H P
Turbine
High
Pressure
Heaters
High
Pressure
Heaters
High
Pressure
Heaters
Boiler
Feed
Pumps
Low
Pressure
Heater
Low
Pressure
Heater
Deaerater
Heated
Feedwater
to Boiler
BFP Recirc.
Condensate
To Hotwell
LP Turbine

81. Automatic Turbine Start-up Control &Automatic Turbine Start-up Control &
Rotor Stress MonitoringRotor Stress Monitoring
 Safe Turbine Start-up and Shut down Sequencing
 OEM guidelines are incorporated using the flowcharts and
rotor stress constants
 ATC mode automatically determines:
 Speed & Load Targets
 Speed Rates & Speed Holds
 Load Rates & Load Holds
 Run backs
 Integral Turbine Protections

82. Typical ATC and RSM ProgramsTypical ATC and RSM Programs
 HP and IP rotor stress calculations
 Steam chest metal required temperature calculations
 Turning gear checks before startup
 Eccentricity and vibration monitoring
 Water detection and drain valve control
 Bearing temperature monitoring
 Generator monitoring and checks before synchronization
 Heat soak calculations allowing for shorter heat soak time

83. Damper
Control
Steam
Temp
Feedwater
HRSG Turbine
Turbine
Master
S-heat
Spray
R-heat
Spray
BF-
Pump
Turbine
Valves
Load Demand
Computer
High Limit
Low Limit
Ramp Rate
Operator
Set Limits
Runbacks
Rundowns
Block Increase
Block Decrease
LocalRemote
GT #1 GT #2
ST MWST MW
DELTADELTA
BALANCERBALANCER
+
-
Load Demand Computer – CCP PlantsLoad Demand Computer – CCP Plants

84.  Front end (LDC Indexer) develops total plant MW demand
 GT MW demand is total plant demand minus actual ST MW
generation
 GTs are in megawatt control mode
 ST is in IPC control mode
 As plant load index increases, the ST TP set point increases
 f(x) has minimum pressure (floor value)
 f(x) curve slides pressure on 100% valve point
Basic CC PlantBasic CC Plant
ControlControl

85. Emerson Gas TurbineEmerson Gas Turbine
ControlControl Automatic startup and shutdown
 Surge control limited starting and under load
 Feed-forward fuel control schedule during
starting
 Temperature override control during starting
 Speed control from tuning gear to minimum
load
 Load control from minimum to base load
 Loading rate control
 Temperature control at load
 Minimum and maximum limits on fuel flow

86. Ovation Gas Turbine Controls OfferOvation Gas Turbine Controls Offer
Numerous AdvantagesNumerous Advantages Advanced control and turbine protection
schemes
 Local and remote operation capability
 Improved data acquisition for predictive
maintenance and scheduling
 Integrated power and BOP control
systems
 Maximize efficiency through load
management
 More precise and reliable fuel control
 Advanced graphical interface
 Historical logging and trending
 Diagnostics for preventative maintenance

87. Modern Power Plant ConsiderationsModern Power Plant Considerations
 Power industry is experiencing a dramatic changes fueled by Deregulation and
consolidation.
 Older business models are changing to cope with Competition between utilities,
environmental concerns, and increasing power demand.
 Availability, reliability, efficiency & lesser operating costs have become key
elements of everyday plant operation considerations.
 Today’s control system networks have become Information networks
 Modern power plants tending to achieve vertical and horizontal integration of
plant wide controls under single hardware/software platform, using Smart Filed
Devices and Industrial standard communication across various layers of
information & control networks.
 Integrated Plant Optimization suites enable efficient optimized continuous plant
controls throughout the plant operation range.
 Plant Web Digital architecture enables easy integration of field devises while
ensuring high quality field intelligence made available to the right persons,
minimizing operational & maintenance costs while maximizing safety.
 Integrated Plant Simulator for efficient operation and management of the plant

88. Air Controls
Fuel
Management
Feedwater
Control
Burner
Management
Condensate
Control
Emergency
Diesel
Circulating
Water
Turbine
Bypass
Combustion
Control
Coordinated
Controls
AGC
Cooling
Tower
Switchyard/
Metering
SCR
Injection
Reagent
Handling
Ammonia
Handling
Sootblower PLCI/O
Fly Ash PLCI/O
Bottom Ash PLCI/O
Dry ESP PLCI/O
Wet ESP PLCI/O
Condensate
Polishing
PLCI/O
Air
Preheater
PLCI/O
Coal
Handling
PLCI/O
Limestone
Stockout
PLCI/O
Gypsum
Handling
PLCI/O
Aux
Boiler
PLCI/O
Makeup
Water
PLCI/O
Demin
Water
PLCI/O
PLCI/O
Limestone
Reclaim
PLC Stations
Hardwired
DataLinks
Turbine StationEmissions StationVibration
Monitoring Station
Hardwired
DataLinks
Turbine
Control
Emissions
Monitoring
Motor/
Transformer
UPS
Monitoring
Vibration
Monitoring
Fire
Detection
DCS Operator Stations
DCS Engineer
Station Historian
Typical Power Plant Controls ArchitectureTypical Power Plant Controls Architecture
PLCsPLCs DCSDCS
33rdrd
PartyParty
SystemsSystems
Local
Display
Local
Display
Local
Display
Emerson Confidential

89. Air ControlsAir Controls Fuel
Management
Fuel
Management
Feedwater
Control
Feedwater
Control
Burner
Management
Burner
Management
Condensate
Control
Condensate
Control
Emergency
Diesel
Emergency
Diesel
Circulating
Water
Circulating
Water
Turbine
Bypass
Turbine
Bypass
Combustion
Control
Combustion
Control
Coordinated
Controls
Coordinated
Controls
AGCAGC Cooling
Tower
Cooling
Tower
Switchyard/
Metering
Switchyard/
Metering
SCR
Injection
SCR
Injection
Reagent
Handling
Reagent
Handling
Ammonia
Handling
Ammonia
Handling
Turbine
Control
Turbine
Control
Emissions
Monitoring
Emissions
Monitoring
Motor/
Transformer
Motor/
Transformer
UPS
Monitoring
UPS
Monitoring
Vibration
Monitoring
Vibration
Monitoring
Fire
Detection
Fire
Detection
Engineer
Station
Historian
SootblowerSootblower
Fly AshFly Ash
Bottom AshBottom Ash
Dry ESPDry ESP
Wet ESPWet ESP
Condensate
Polishing
Condensate
Polishing
Air
Preheater
Air
Preheater
Coal
Handling
Coal
Handling
Limestone
Stockout
Limestone
Stockout
Gypsum
Handling
Gypsum
Handling
Aux
Boiler
Aux
Boiler
Makeup
Water
Makeup
Water
Demin
Water
Demin
Water
Limestone
Reclaim
Limestone
Reclaim
Emerson’s Modern Power Plant ControlsEmerson’s Modern Power Plant Controls
Asset
Mgmt
Station
Wireless and
Web-based
Interfaces
Fieldbus-based Ovation Expert System
SimulatorOperator Stations
Emerson Confidential

90. Total Solutions From The Power IndustryTotal Solutions From The Power Industry
SpecialistsSpecialists
Business Level
Optimization & Predictive
Maintenance
Expert Control
Instrumentation
Applications