3. BOILER / STEAM TURBINE-GENERATOR
INDUSTRIAL CO-GENERATION
Process Steam
65%
15%
Process Plant
Stack
Steam 5% Aux. Power + Losses
15% Electricity
Fuel
100%
Air
Boiler Steam Turbine Generator Transmission
THERMAL EFFICIENCY - 80%
4. SIMPLE CYCLE COMBUSTION (GAS) TURBINE
57-62%
100% Fuel Stack
Combuster 3% Aux Power + Losses
35-40% Electricity
Air
Compressor Turbine
Generator Transmission
THERMAL EFFICIENCY - 35-40%
5. GAS TURBINE
INDUSTRIAL CO-GENERATION PLANT
20%
Stack Stack
Supplementary/
Auxiliary
Fuel (Optional) Process Steam
Process Plant
100% Fuel
Combuster Exhaust Gas
Air
Compressor Turbine
Generator Transmission
6. GAS TURBINE 28%
COMBINED CYCLE POWER PLANT
Steam Condenser
20%
Stack
Stack
Steam Lake
Supplementary
Fuel (Optional)
100% Fuel
Steam Turbine Generator
Transmission
Combuster Exhaust Gas 12-15% Electricity
Air 6% Aux. Power + Losses 35-40% Electricity
Compressor
Turbine Generator Transmission
Thermal Efficiency - 45-55%
7. UTILITY PLANT - FUNCTIONAL BLOCK DIAGRAM
Switch Yard System Ash Handling System Station Electrical System
Boiler Steam & Water System
Air & Flue Gas System
BOILER Fuel Preparation System
Fuel Firing System
Boiler Miscellaneous Systems
Boiler Feed Pumps &
UNIT#2
Deaerator System
Turbine Steam System
TURBINE- HP & LP Heaters System
GENERATOR
Turbine Supervisory & Control
System
Generator & Electrical System
Turbine Miscellaneous Systems
Turbine Bypass System
Fuel Handling System
DM Plant Station Miscellaneous Systems
8. CAPTIVE POWER PLANT - FUNCTIONAL BLOCK
DIAGRAM
Switch Yard System Ash Handling System Station Electrical System
Steam & Water
Air & Flue Gas
BOILER
Fuel Preparation
Fuel Firing
Steam UNIT#2 UNIT#3
TG HP & LP Heaters
Supervisory & Control
Generator & Electrical
Miscellaneous Systems
BFP’s & Deaerator System
Fuel Handling System
DM Plant Station Miscellaneous Systems
10. BASIC DIAGRAM OF A BOILER
Steam
Water
Steam / Water System Blowdown
Fuel
Flue Gas
Mixing of Heat Transfer
Fuel & Air Surface
Furnace
Air Ash
11. SALIENT FEATURES OF MODERN INDUSTRIAL
& UTILITY BOILER
• STEAM BOILER
• WATER TUBE
• SUPERHEATED STEAM
• HIGH PRESSURE
• WATER COOLED FURNACE
• WATER CIRCULATION
12. COMBUSTION REQUIREMENTS
Sufficient
Combustion Air
Temperature
Fuel Combustion
Mixing within above
is Time
Flammable Ignition
Gasified Temperature
Range Point Turbulence
3 T’s of Combustion
13. BASIC COMBUSTION CHEMISTRY
Complete Heat
(Air) Oxygen Fuel Flue Gas
Products
H2 H2O
O2 + C CO2
Incomplete
Heat
Oxygen Fuel Flue Gas
Products
H2
H2O
O2 + C
CO2
CO
H2
C
• Other Combustibles - Sulphur to Sulphur Oxides
• Non-combustible - Nitrogen to Nitrogen+Nitrous Oxides
• Ash
14. BOILER WATER & STEAM SYSTEM Hot Reheat
Steam
Spray
Water Main Steam
Drum
Attemperator
Attemperator
Cold
Final Primary Final Reheat
Platen Primary
Re Re Super Steam
Super Super
Heater Heater Heater Spray
Heater Heater
Water
Down
Comers Flue Gas
Economiser
Feed Water
Furnace
Flue Gas
Water Wall Out to
Risers Air Heater
Bottom Ring Header
Simplified Process Diagram
15. BOILER WATER & STEAM SYSTEM
Process Performance Highlights
• Heat Transfer by Radiation and Convection
• Boiler Water Circulation - Natural or Controlled
• Heat Transfer depends on Heat Transfer Area & Time
• Heat Transfer is affected by Fouling, Boiler Pressure, Boiler Water Quality
and % MCR Load
16. BOILER WATER & STEAM SYSTEM
Major Equipment
• Economiser - Pre-heats Boiler Feed water
• Boiler Drum - Separates water from steam and reduce solids in steam
• Water Walls - Absorb heat from flue gas to evaporate boiler water
• Superheaters - Heat up steam coming from boiler drum
• Reheaters - Heat up steam coming from High Pressure turbine
• Attemperators - Reduce superheat from steam
17. BOILER WATER & STEAM SYSTEM
Process Regulation
• Drum Level - Regulation of Feed Water flow
• Drum Water Quality - Blow down / Chemical Dozing
• Fouling of Heat Transfer Surfaces - Blowdown / Soot Blowing
• Main Steam Temperature - Attemperation / Burner Tilt
• Hot Reheat Steam Temperature - Burner Tilt / Attemperation
• Main Steam Pressure - Regulation of Combustion
18. AIR & FLUE GAS SYSTEM
To Air Cooled PA FAN A
To Hot To Cold
Guns PA Header PA Header
From
Scanner Air Fans FD Fans
PA FAN B
WINDOX A
AH A
ESP A
P F L
R E
T I T ID Fan A
FURNACE H C
N N S Chimney
O
S S H
H H ID Fan B
ESP B
AH B
WINDBOX B
FD FAN A
FD FAN B
Simplified Process Diagram
19. AIR & FLUE GAS SYSTEM
Process Performance Highlights
• Generation of Draft - Natural / Induced / Forced / Balanced
• Supply of Air for Transport of Pulverised Coal
• Pre-heating of Air
• Distribution of Air in Combustion Chamber
• Recirculation of Gas
• Fan capacity depends on Flow, Density & System Resistance
• Fan performance is affected by temperature, density, barometric pressure
and speed
• Flue Gas Cleaning
• Gas flow is restricted by ash deposits on boiler surfaces
20. AIR & FLUE GAS SYSTEM
Major Equipment
• Air Path - Forced Draft Fans, Steam Coil Air Pre-heater,
Regenerative Air Pre-heater & Wind-box
• Gas Path - Induced Draft Fans and Stack
• Gas Recirculation - Gas Recirculating Fans
• Flue Gas Cleaning - Mechanical Precipitator, Electrostatic
Precipitator and Gas Scrubber
• Dampers
21. AIR & FLUE GAS SYSTEM
Process Regulation
• Furnace Draft - ID Fan Inlet Vane Control and/or Variable Speed
• Secondary Air Flow - FD Fan Variable Pitch Control
• PA Header Pressure - PA Fan Inlet Vane Control
• RAPH Cold End Temperature - SCAPH Control
• Gas Recirculation - Damper Control
22. FUEL PREPARATION SYSTEM - COAL
Raw Coal Bunker To Mill Discharge
Valves
To Hot PA
Other
Coal Feeder Mills
Coal+Air
to Burners
Mill A Cold PA
To
Other
Mills
To Other Mills Seal Air Fans
Simplified Process Diagram
23. FUEL PREPARATION SYSTEM - GAS/OIL
Fuel Gas
Supply To Burners
FCV FGTV
PRV’s
FUEL GAS
Atomising
Steam/Air
PCV
Fuel Oil
Return
Short Long
Recirc Recirc
PCV
Fuel Oil
Oil Heater To Burners
Supply
FCV FOTV
Steam
Fuel Oil Pumps
FUEL OIL
Simplified Process Diagram
24. FUEL PREPARATION SYSTEM
Process Performance Highlights
• Coal Pulverizing - Direct / Indirect Firing
• Coal Transport and Drying
• Fuel Gas Pressure Regulation
• Fuel Oil Pumping & Filtering
• Fuel Oil Pressure & Viscosity Regulation
• Gas Pressure & Oil Pressure/Temperature affect Boiler
Load
25. FUEL PREPARATION SYSTEM
Major Equipment
• Coal Mills - Tube Ball / Bowl / Impact
• Raw Coal Feeders - Chain / Belt / Rotary / Gravimetric
• Coal / Air Dampers, Gates & Discharge Valves
• Fuel Oil Pumps & Heaters
• Seal Air Fans
• Coal Bunkers
• Vapour Fans
26. FUEL PREPARATION SYSTEM
Process Regulation
• Coal Flow - Raw Coal Feeder Speed
• Coal/Air Temperature & Flow - Cold & Hot PA Flows
27. FUEL FIRING SYSTEM
OFA
OFA
FF EA
F FA
(2) (3) Air Damper
EF AA
E OFA Over Fire Air
EA End Air
DE FA Fuel Air
D AA Aux. Air
Front Wall
Coal Burner
CD (4)
(1)
Fire Ball Scanner
Plan
C
(Corner Designation) LFO?HFO Burner
BC
B HFO Burner
Oil Flame Scanner
AB
A HEA Igniter
AA
Typical Corner Arrangement
for a Tangentially Fired System
28. FUEL FIRING SYSTEM
Process Performance Highlights
• Fuel Firing - Front / Tangential
• Fuel Oil Atomisation - Mechanical / Air / Steam
• Flame Ignition
• Air Distribution
• Fuel Combustion
30. FUEL FIRING SYSTEM
Process Regulation
• Furnace to Wind Box Differential Pressure
• Fuel Air Flows
• Fuel Firing
• Emergency Shutdown
• Flame Monitoring
• Oil Support for Coal Flame Stability
31. BOILER MISCELLANEOUS SYSTEMS
Boiler Auxiliary Cooling Water System
• Ensures continuous supply of cooling water to Boiler & it’s auxiliaries
• Consists of Overhead Tank, Pumps & Heat Exchangers
Chemical Dosing System
• Prepares & supplies chemicals for treatment of Boiler Water
• Consists of Preparation Tanks, Mixers & Metering Pumps
32. DEAERATION & FEED PUMPING SYSTEM
Condensate from LP Heater
To HP
HP Heater Drains
Aux. Steam Heaters
CRH Steam
Deaerator
IPT Extraction
Aux. Steam Steam
for Feed Storage Tank
Pegging To HP Bypass
Spray
Hydrazine T o APRDS
Dosing Spray
Ammonia Recirculation
Dosing Valve
M
Discharge Valve
Boiler Feed Pumps
Simplified Process Diagram
33. DEAERATION & FEED PUMPING SYSTEM
Process Performance Highlights
• Boiler Water pre-heating & air removal
• Maintain positive Suction Pressure for Feed Pumps
• Feed Water Pumping to Boiler
34. DEAERATION & FEED PUMPING SYSTEM
Major Equipment
• Boiler Feed Pumps
• Hydraulic Coupling
• Deaerator
37. LAWS OF THERMODYNAMICS
• Conservation of Energy - Heat may be converted in to work and
work may be converted in to heat,
in accordance with a certain natural proportionality constant
(ENERGY CAN NOT BE DESTROYED)
• Not all of a given quantity of Heat can be converted in to useful Work,
because of irreversbility in the process
(ENTROPY OF THE UNIVERSE IS INCREASING)
41. TURBINE STEAM SYSTEM
Main
Steam
ESV CV HP IP
Turbine Turbine LP
Turbine
Cold
Reheat
Steam
Condenser
Hot
Reheat
Steam
IV CV
Extraction
Steam
Simplified Process Diagram
42. TURBINE STEAM SYSTEM
Major Equipment
• Turbine - Casing, Rotor & Blades
• Emergency Stop Valves
• Control Valves
• Condenser
44. REGENERATIVE FEED HEATING SYSTEM
To From BFP To
Boiler Discharge Deaerator LPT
CRH Extraction Steam
Steam
To
Deaerator LP
HP
HTR
HTR
LPT Condenser
IPT Extraction Steam Gland
Extrn. Leakoff
Steam LP Steam
HP HTR Minimum Makeup
HTR Recirculation Hotwell
LPT Extraction
To
Condenser
LP Drain
To GSC HTR CLR
HP Condenser LP
Flash Flash
Tank Tank
Condensate Extraction
Pump
Simplified Process Diagram
45. REGENERATIVE FEED HEATING SYSTEM
Process Performance Highlights
• Pumping of Condensate from Hotwell to Deaerator
•Gradual Heating of Feed Water Temperature
• Minimise Heat Loss from the Cycle
46. REGENERATIVE FEED HEATING SYSTEM
Major Equipment
• HP Heaters
• LP Heaters
• Drain Cooler
• Condensate Extraction Pumps
47. REGENERATIVE FEED HEATING SYSTEM
Process Regulation
• Hotwell Level
• Heater Level
• Minimum Flow through CEP & GSC
48. TURBINE GOVERNING & CONTROL SYSTEM
Governing
Oil
System
Turning
Gear
Jacking Condenser
Oil Vacuum
System System
Lubricating Gland Turbine
Oil Steam Drain
System System
System
OIL SYSTEMS VACUUM SYSTEM WARM UP SYSTEM
Functional Block Diagram
49. TURBINE GOVERNING & CONTROL SYSTEM
Process Performance Highlights
• Shaft & Bearing Protection
• Electro-hydraulic Governing
• Maintain Vacuum in Condenser
• Supply Steam to Turbine Glands
• Warming up of Turbines and their Valves
• Emergency Shutdown in case of Unsafe Conditions
50. TURBINE GOVERNING & CONTROL SYSTEM
Major Equipment
• Oil Pumps, Turning Gear & Jacking Oil Pump
• Hydraulic Actuators for Turbine Valves
• Vacuum Pumps
• Gland Steam Pressure Regulator
• Oil Coolers & Temperature Regulator
51. TURBINE GOVERNING & CONTROL SYSTEM
Process Regulation
• Speed / Load / Frequency Control
• Gland Steam Pressure Control
52. TURBINE MISCELLANEOUS SYSTEMS
Condenser Cooling Water System
• Supplies Cooling Water Condensation of Turbine Exhaust Steam
Turbine Auxiliary Cooling Water System
• Ensures continuous supply of cooling water to Turbine & it’s auxiliaries
• Consists of Overhead Tank, Pumps & Heat Exchangers
Chemical Dosing System
• Prepares & supplies chemicals for treatment of Condensate
• Consists of Preparation Tanks, Mixers & Metering Pumps
53. TURBINE MISCELLANEOUS SYSTEMS
Condenser Cooling Water System
CW Return Header
Cooling Condenser Waterbox
Tower
To A B
Unit#2
CW
Sump
CW
Makeup
Water
CW Supply Header
Circulating
Water Pumps
Simplified Process Diagram
54. TURBINE MISCELLANEOUS SYSTEMS
Condenser Cooling Water System
Major Equipment
• Cooling Towers
• CW Pumps
Process Performance Highlights
• Steam Condensation
• Cooling of Condenser CW - Cooling Tower / Lake
Process Regulation
• Condenser Tube Cleaning - Online / Back flushing
55. TURBINE BYPASS SYSTEM
Main
Steam
To HPT
Feed
Water PRV
Block Spray
Valve Control
Valve
CRH
From HPT
HRH To IPT
Condensate
Condenser
Simplified Process Diagram
56. TURBINE BYPASS SYSTEM
Process Performance Highlights
• Enable Boiler Operation for Quick Re-start after Boiler Trip and
during Turbine Start-up
• Control MS Pressure after Turbine Trip or Sudden Load Throw-off
57. TURBINE BYPASS SYSTEM
Process Regulation
• MS Pressure Reduction & Desuperheating
• HRH Steam Pressure Reduction & Desuperheating
59. WORKING PRINCIPLE
• Converts Mechanical Energy in to Electrical Energy
• Based on Electro-magnetic Induction
E = 4.44 O FN volts
E - e. m. f.
O - Strength of Magnetic Field
F - Frequency
N - No. of Turns in a Stator Winding Coil
F = Pn/120
P - No. of Poles
n - Revolution per second of Rotor
60. GENERATOR EFFICIENCY & LOSSES
• Efficiency = Output Electrical Energy
Input Mechanical Energy
• Losses - Bearing Loss, Copper Loss & Iron Loss
• Typically Efficiency is 90-97%
61. GENERATOR & UNIT ELECTRICAL SYSTEM
Metering &
Protective
Relays
Seal
Generator
Oil
Transformer
System
Generator Hydrogen
Synchronising Cooling
Sceme System
Unit Field Stator
Auxiliary Excitation Cooling Water
Transformer System System
ELECTRICAL SYSTEMS MECHANICAL SYSTEMS
Generator Functional Block Diagram
62. GENERATOR & UNIT ELECTRICAL SYSTEM
Isolator 132 KV Bus I
132 KV Bus II
Circuit Breaker
Unit
GT
Auxiliary
Transformer
From
11 kV From
Station
Station
Bus
Bus
Generator
6.6 kV Unit Bus A 6.6 kV Unit Bus B
Key One Line Diagram
63. GENERATOR & UNIT ELECTRICAL SYSTEM
Process Performance Highlights
• Conversion of Mechanical Energy in to Electrical Energy
• Field Excitation
• Stator Winding Cooling by Distillate / Air
• Rotor Winding Cooling by Hydrogen / Air
• Hydrogen Sealing by Oil
• Synchronisation & Voltage Transformation
• Emergency Shutdown in case of Unsafe Conditions
64. GENERATOR & UNIT ELECTRICAL SYSTEM
Major Equipment
• Generator - Stator, Rotor, Armature Windings, Field Windings
• Field Excitation - Exciter (DC/AC), Static Rectifying Unit & AVR
• Bus Ducts & Transformers
• Circuit Breakers & Protective Relays
• H2 Cooling - Fans, Dryers & Coolers
• Stator Water Cooling - Pumps, Coolers & Overhead Tank
• Seal Oil - Pumps, Coolers & Differential Pressure Regulator
65. GENERATOR & UNIT ELECTRICAL SYSTEM
Process Regulation
• Field Excitation
• Generator Synchrinisation
• Voltage Regulation
68. OPERATION & MAINTENANCE
Factors Affecting Plant Performance
• Flue Gas Exit Temperature
• Excess Air
• Unburnt Fuel
• Steam Temperature
• Condenser Back Pressure
• FW Temperature at Eco Inlet
• Auxiliary Power Consumption
• Make up Water Flow
• Optimum Loading
71. POWER PLANT AUTOMATION & CONTROL
Burner Management System
• Furnace Purge Supervision
• Secondary Air Damper Modulation, On/Off Control and Supervision
• Light/Heavy Oil On/Off Control and Supervision
• Pulveriser and Feeder On/Off Control and Supervision
• Flame Scanning
• Overall Boiler Flame Failure Protection
• Boiler Trip Protection
72. POWER PLANT AUTOMATION & CONTROL
Soot Blower Sequential Control
• Wall Blowers
• Long Retractable Blowers
• Air Heater Blowers
73. POWER PLANT AUTOMATION & CONTROL
Automatic Turbine Run-up System
• Oil Supply Control - Turning Gear, Auxiliary Oil Pumps, Emergency Oil Pump,
Jacking Oil Pump and Lube Oil Temperature
• Condensate & Evacuation Control - Condensate Extraction Pumps, Gland Steam
Pressure, Vacuum Pumps and Vacuum Breaker Valve
• Turbine Control - Steam & Metal Temperature Matching, Warming up of HP
ESV & CV, Steam Rolling & Acceleration and Auto Synchroniser
74. POWER PLANT AUTOMATION & CONTROL
Turbine Stress Evaluator
• Calculation of Actual and Permissible Thermal Stress Values
• Comparison of Actual with Permissible Stress Values and Computation
of Available Margin
• Optimize Start up, Operation and Shut down
75. POWER PLANT AUTOMATION & CONTROL
Automatic Turbine Tester
• Safety Devices - Remote Trip, Over-speed, Low Vacuum and
Thrust Bearing
• HP/IP Valves - HP Stop and Control Valves, and IP Stop and
Control Valves
76. POWER PLANT AUTOMATION & CONTROL
Electro-hydraulic Governing System
• Speed Control
• Load Control
• Load Shedding
• Initial Pressure Control
77. AUTOMATION & CONTROL
CRITICAL CLOSED LOOPS
• CMC - Boiler Follow / Turbine follow / Coordinated (Utility)
• Header Pressure Control (CPP)
• Combustion - Fuel / Air Flow
• Steam Temperature
• Drum Level
• Furnace Draft
78. AUTOMATION & CONTROL
OPEN LOOP CONTROL
• Interlocking - Safe Startup / Shutdown
• Protection - Emergency Shutdown (Trip)
• Sequencial Control - Efficient Startup / Shutdown
CRITICAL OPEN LOOPS
• ID/FD /PA Fans
• BFP