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EMERSON Process Management Water & Power Solution( PWS)
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Power Plant ApplicationsPower Plant Applications
Nigam SharmaNigam SharmaSr. Regional Manager, Asia PacificSr. Regional Manager, Asia Pacific
AgendaAgendaAgendaAgenda
Power Plants Over View
Main Components of a Power Plant
Typical Controls Applications
Types of PlantsTypes of PlantsTypes 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
XX
Thermal Plant OverviewThermal Plant OverviewThermal Plant OverviewThermal Plant Overview1. 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
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 ComponentsMajor ComponentsMajor Components
BottomAsh
System
EconomizerHoppers
F DFanGeneral
Water
Sump
BOTTOMASH
HOPPER
SettlingPond
WATER
TREATMENT
CoalBunker
Conveyors
Pulverizers
Load
Gen.HP IP L P
Turbine
Econ-omizer
Re-Heat
SuperHeater
DRUM
Condenser
P AFan
IDFans
HPFW
Htr
LPFW
Htr
AshTransfer
Water
Clean-up
PrecipitatorsStackGas
Scrubber
EmissionsMonitor
Flyash
Cond.Pump
BFPDeaerator
CoolingWater
Feeder
Downcomers
Risers
Air Heater
Power Plant Process MapPower Plant Process MapPower Plant Process MapPower Plant Process MapWater Vapor &
Scrubbed Gases
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.
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.
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.
Various Boiler TypesVarious Boiler Types
HPFW
HTR
LPFW
HTR
HP L PSecondarySuperHeater
Power Plant Process Power Plant Process MapMapOnce-Thru Boiler
BFP
Water Vapor &Scrubbed Gases
Load
Gen.
Turbine
Econ-omizer
Re-Heat
Condenser
IDFan
PrecipitatorsStackGas
Scrubber
EmissionsMonitor
Flyash
Deaerator
CoolingWater
BottomAsh
System
EconomizerHoppers
F DFan
SettlingPond
AshTransfer
Water
Clean-up
Cond.Pump
General
Water
Sump
CoalBunker
Conveyors
PulverizersP AFan
Feeder
PrimarySuperHeater
IP
Air Heater
BOTTOMASH
HOPPER
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
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.
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.
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
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
Combined Cycle Power GenerationCombined Cycle Power Generation
Thermal Efficiency = 45-55%
35-40% Electricity
Generator
6% Aux. Power + LossesAir
100% Fuel
Combuster
Stack
20%
Compressor Turbine
28%Steam Condenser
HRSG
SteamSupplementaryFuel (Optional)
ExhaustGas
Steam TurbineGenerator
12-15% ElectricityLake
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
CoolingTowers
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
BypassDamper
Most Common Combined Cycle Most 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
LegendGT – Gas Turbine Gen - GeneratorST – Steam Turbine HRSG – Heat Recovery Steam Generator
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 BoilersLow Calorific Value, high moisture, low Sulphur fuels
Bagasse, Rice husk, Rice Straw, Wood Chips etc
Industrial Co-GenerationIndustrial Co-Generation
BagasseRice HuskRice Straw
Wood ChipsEtc.
Thermal Efficiency = 80%
District HeatingDistrict Heating
15%
Steam
Stack
Air
15% Electricity
Boiler Steam Turbine Generator
5% Aux. Power + Losses
HeatExchanger
55%
SteamCondenser10% Losses
FeedwaterLoop
Thermal Efficiency = 70%
Power Plants ControlsPower Plants ControlsCapabilityCapability
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
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
Typical CCPP Control FunctionsTypical CCPP Control Functions
HRSG (Heat Recovery Steam Generator) Boiler Controls Un-fired HRSG
Bypass Damper ControlFeedwater - Drum Level ControlLive Steam Temperature ControlTurbine Bypass ControlDeaerator Level ControlHotwell Level ControlAdvanced 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
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 ControlsFlue Gas De-Sulphurization ControlsScrubber Controls
Motor Controls Electrical Controls & Monitoring
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 Control Concept of a Unit Control
Binary ControlBinary Control
Drive Control Standards for: low voltage motors high voltage motors open/close valves or dampers electrical actuators
Sequential ControlSequential ControlFeatures 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 Control Concept of a Unit Control
Modulating ControlModulating 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 Control Concept of a Unit Control
Coordinated Unit ControlsCoordinated Unit Controls
Coordinated Unit ControlsCoordinated Unit Controls
ADSInterface
UnitMaster
BoilerMaster
FuelMaster
AirSteamTemp Feedwater
Boiler Turbine
TurbineMaster
Mill 1 Mill nID
FansFD
Fans
Furnace Draft
S-heatSpray
R-heatSpray
BF-Pump
TurbineValves
Load Demand
Front End
Front End SystemFront End System
ADSInterface
UnitMaster
BoilerMaster
FuelMaster
AirSteamTemp Feedwater
Boiler Turbine
TurbineMaster
Mill 1 Mill nID
FansFD
Fans
Furnace Draft
S-heatSpray
R-heatSpray
BF-Pump
TurbineValves
Load Demand
ADSInterface
FuelMaster Air
SteamTemp
Feedwater
BoilerTurbine
Front End
Mill 1 Mill n IDFans
FDFans
Furnace Draft
S-heatSpray
R-heatSpray
BF-Pump
TurbineValves
Load Demand
Load Demand Computer(LDC)
Load Demand ComputerLoad Demand Computer
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
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
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
Turbine Master (Fixed Pressure) regulates turbine to satisfy megawatt demand Recognizes boiler’s response capabilities
Turbine MasterTurbine Master
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
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
ADSInterface
LDC
BoilerMaster
FuelMaster
AirSteamTemp
Feedwater
Boiler Turbine
TurbineMaster
Mill 1 Mill nID
FansFD
Fans
FurnaceDraft
S-heatSpray
R-heatSpray
BF-Pump
TurbineValves
Load Demand
Fuel MasterFuel Master
Fuel Fuel 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
Fuel Fuel 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
ADSInterface
LDC
BoilerMaster
FuelMaster
AirSteamTemp
Feedwater
Boiler Turbine
TurbineMaster
Mill 1 Mill nID
FansFD
Fans
FurnaceDraft
S-heatSpray
R-heatSpray
BF-Pump
TurbineValves
Load Demand
Air Flow Air 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)
Air Flow Air 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
ADSInterface
LDC
BoilerMaster
FuelMaster
AirSteamTemp
Feedwater
Boiler Turbine
TurbineMaster
Mill 1 Mill nID
FansFD
Fans
FurnaceDraft
S-heatSpray
R-heatSpray
BF-Pump
TurbineValves
Load Demand
Feedwater Feedwater 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
Drum level Drum level ControlControl
ADSInterface
LDC
BoilerMaster
FuelMaster
AirSteamTemp
Feedwater
Boiler Turbine
TurbineMaster
Mill 1 Mill nID
FansFD
Fans
FurnaceDraft
S-heatSpray
R-heatSpray
BF-Pump
TurbineValves
Load Demand
Steam Steam 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
Steam Steam 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
Furnace 2 nd
S.H.
PID
PID
PID
PID
X
Firing Rate
BoilerMaster
Desired Spray(20%)
WW OutletTemp
LDCOut
Economizer
Fuel/Air
4 th
S.H.3 rd
S.H.
PID
FW FlowControl
FW/FRratio
DMCAlgorithm
SUM
RHTilts/Damper
Setpoints2nd, 3rd and 4th SH
1st
S.H.
APC Steam Temperature Control APC Steam Temperature Control SchemeScheme
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 System Burner Management System
DefinitionDefinition
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 System Burner Management System
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
Burner ArrangementsBurner ArrangementsWall-Fired Tangential Corner-Fired
Slag
Crushed CoalAir Secondary
Furnace
Primary Furnace
Cyclone(B&W Exclusive)
Burner ArrangementsBurner Arrangements
MultipleElevations
To otherburners
this elevation
DriveMotor
Pulvorizeror ‘Mill’
Feeder
CoalBunker
Air in
Boiler
One of six;one per burner
elevation
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
IgnitionTransformer
Igniter
Damper
Damper
PurgeAir
Main Burner
IgnitionFlame
MainFlame
IgnitionFlameDet.
MainFlame
Det
CoolingAir
WindBox
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
Turbine Master
BoilerMaster
Feedwater Combustion
FuelValve FD Fan ID FanPump
(Turbine)Pump(Shaft)
Pump(Standby)
Load DemandComputer
High Limit
Low Limit
Ramp Rate
OperatorSet Limits
RunbacksRundownsBlock IncreaseBlock Decrease
Contingency
Digital Control
LocalRemote
Valve Positioner
PassDampers Spray
Steam Temp.
Steam Turbine ControlsSteam Turbine Controls
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
Turbine Control Requires Specialized I/OTurbine Control Requires Specialized I/O
Speed Detector Module
Valve Positioner Module
Servo Driver Module
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
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
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
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
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
Typical Large Steam Typical Large Steam TurbineTurbine
HPTURBINE
IPTURBINE
LPTURBINE
SPEEDSENSING
CONTROLSYSTEM
CONTROLINPUT
STEAMGEN
INTERCEPTVALVE(S)
REHEAT STOPVALVE(S)
REHEATAND/OR
MOISTURESEPARATOR
CONDENSER
(W) GOVERNOR/(GE) CONTROL
VALVE(S)
(W) THROTTLE/(GE) STOPVALVE(S)
CROSSOVER
GENERATOR
GENERATORBREAKER
1
3
5
2
63
5
12
4
6
4
Main Steam Supply
Governor/ControlValves
Governor/ControlValves
Throttle/Stop
Valve 1
Throttle/Stop
Valve 2
NozzleBlock
Full Arc / Single Valve Mode = All Governor/Control Valves opened togetherPartial Arc / Sequential Valve Mode = Governor/Control Valves opened independently
Steam Flow Through Nozzle BlockSteam Flow Through Nozzle Block
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
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
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
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
Turbine Bypass System for Thermal PlantTurbine Bypass System for Thermal Plant
Turbine Bypass System for CCP PlantTurbine Bypass System for CCP Plant
Typical Large Steam TurbineTypical Large Steam TurbineExtraction Steam and Heater SystemsExtraction Steam and Heater Systems
I PTurbine
H PTurbine
HighPressureHeaters
HighPressureHeaters
HighPressureHeaters
BoilerFeed
Pumps
LowPressure
Heater
LowPressure
Heater
Deaerater
HeatedFeedwaterto Boiler
BFP Recirc.
Condensate
To Hotwell
LP Turbine
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
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
Damper Control
SteamTemp
Feedwater
HRSG Turbine
TurbineMaster
S-heatSpray
R-heatSpray
BF-Pump
TurbineValves
Load DemandComputer
High Limit
Low Limit
Ramp Rate
OperatorSet Limits
RunbacksRundownsBlock IncreaseBlock Decrease
LocalRemote
GT #1 GT #2
ST MWST MWDELTADELTA
BALANCERBALANCER
++--
Load Demand Computer – CCP PlantsLoad Demand Computer – CCP Plants
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 Plant Basic CC Plant ControlControl
Emerson Gas Turbine Emerson 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
Ovation Gas Turbine Controls Offer Ovation 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
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
Air ControlsFuel
ManagementFeedwater
ControlBurner
Management
CondensateControl
Emergency Diesel
CirculatingWater
TurbineBypass
Combustion Control
CoordinatedControls
AGCCooling Tower
Switchyard/Metering
SCR Injection
Reagent Handling
AmmoniaHandling
Sootblower PLCI/O
Fly Ash PLCI/O
Bottom Ash PLCI/O
Dry ESP PLCI/O
Wet ESP PLCI/O
CondensatePolishing PLCI/O
AirPreheater PLCI/O
CoalHandling PLCI/O
LimestoneStockout PLCI/O
GypsumHandling PLCI/O
AuxBoiler PLCI/O
MakeupWater PLCI/O
DeminWater PLCI/O
PLCI/OLimestoneReclaim
PLC Stations
Har
dwire
d D
ata
Link
s
Turbine StationEmissions StationVibration Monitoring Station
Har
dwire
d D
ata
Link
s
Turbine Control
EmissionsMonitoring
Motor/Transformer
UPS Monitoring
VibrationMonitoring
FireDetection
DCS Operator StationsDCS Engineer
Station Historian
Typical Power Plant Controls ArchitectureTypical Power Plant Controls Architecture
PLCsPLCs DCSDCS
33rdrd Party PartySystemsSystems
LocalDisplay
LocalDisplay
LocalDisplay
Emerson Confidential
Air ControlsAir Controls Fuel Management
Fuel Management
FeedwaterControl
FeedwaterControl
BurnerManagement
BurnerManagement
CondensateControl
CondensateControl
Emergency Diesel
Emergency Diesel
CirculatingWater
CirculatingWater
TurbineBypassTurbineBypass
Combustion Control
Combustion Control
CoordinatedControls
CoordinatedControls AGCAGC Cooling
TowerCooling Tower
Switchyard/Metering
Switchyard/Metering
SCR Injection
SCR Injection
Reagent HandlingReagent Handling
AmmoniaHandlingAmmoniaHandling
Turbine Control
Turbine Control
EmissionsMonitoringEmissionsMonitoring
Motor/Transformer
Motor/Transformer
UPS Monitoring
UPS Monitoring
VibrationMonitoringVibration
Monitoring
FireDetection
FireDetection
Engineer
StationHistorian
SootblowerSootblower
Fly AshFly Ash
Bottom AshBottom Ash
Dry ESPDry ESP
Wet ESPWet ESP
CondensatePolishing
CondensatePolishing
AirPreheater
AirPreheater
CoalHandling
CoalHandling
LimestoneStockout
LimestoneStockout
GypsumHandlingGypsumHandling
AuxBoilerAux
Boiler
MakeupWater
MakeupWater
DeminWaterDeminWater
LimestoneReclaim
LimestoneReclaim
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
Total Solutions From The Power Industry Total Solutions From The Power Industry SpecialistsSpecialists
Business Level
Optimization & Predictive Maintenance
Expert Control
Instrumentation
Applications
