PPT in Relation to Power Plant familarisation, Coal to Electricity Basics,Power Plant cycles, Concepts of Supercritical Technology Boiler, Concepts Of BTG Package as well as Balance of Plant
2. WHY TO OWN CAPTIVE POWER
PLANT
Sl
No
Description TG Set DG Set SEB
1
Interruption of Power
Supply
- NA - - NA - Possible
2
Power Restriction /
Demand Control
- NA - - NA - Possible
3
Controlling of Voltage &
Frequency
Possible Possible Not Possible
4 Initial Cost Very High High Less
5 Production Cost
Rs. 2.75 /
Unit
Rs. 3.80 /
Unit
Demand : Rs. 150 /
KVA
Energy : Rs. 7.15 / Unit
6 Pollution Problem Less Less Nil
7
Banking / Selling of
Excess Power
Possible Possible - NA -
8 Maintenance Cost Moderate Very High Less
3. FUEL
POWER PLANT
Non Conventional Fuel / Sources Conventional Fuel
Wind
Solar
Ocean
Husk
Baggas
Diesel
Furnace Oil
Coal
Lignite
Gas
Non-Conventional Fuel
4. Coal to Electricity ….. Basics
Coal
Chemical
Energy
Super Heated
Steam
Pollutants
Thermal
Energy
Turbine
Torque
Heat LossIn
Condenser
Kinetic
Energy
Electrical
Energy
Alternating current
in Stator
Mech. Energy
LossASH
Heat
Loss
Elet. Energy
Loss
6. RANKINE CYCLE
• The Carnot Cycle is theoretically most efficient, but it is
having practical difficulties.
• For steam power plant, practical thermal cycle was
suggested by Rankine, called Ideal cycle or Rankine
cycle.
3-3’ – BFP raises pressure from p2 to p1
3’-4 – Heating In feed heaters & eco
4 -1 – Heating In boiler
1-2 – Work done in Turbine from p1 to p2
1
2
3
3’
4
T
S
T1
T2
p1
p2
7. THERMAL EFFICIENCY OF RANKINE
CYCLEQ1-Q2 W Useful work
• η = ------- = --- = ----------------
Q1 Q Heat supplied
Rejected Heat
• η = 1 - --------------------
Useful Heat
T1 - T2 T2
• η Carnot = -------- = 1 - ---
T1 T1
• To achieve more efficiency T2 should be as low as
possible and T1 should be as high as possible
8. METHODS OF INCREASING RANKINE
CYCLE EFFICIENCY
Raising supply temperature by super heating.
Increasing the inlet temperature will raise the heat supply to the
cycle more than the heat rejection.
Raising inlet pressure of steam :
Increasing the pressure will mean increase in saturation
temperature at which steam evaporates thus increasing the average
inlet temperature (T1)
9. Dropping the final pressure (or temperature) at which heat is
rejected.
Regenerative Heating : Heating the feed water pumped to Boiler
by bleeding steam from turbine.
Reheat Cycle : Reheating of steam in boiler after it has already
expanded in HP Turbine will avoid moisture formation in LT
Turbine. Also, more heat content of steam before IP Turbine, will
improve efficiency.
10. WHY SUPERCRITICAL PRESSURE
A Boiler operating at a pressure above critical
point is called ‘SUPERCRITICAL BOILER’
A point where boiling water and dry saturated
lines meet so that associated latent heat is zero,
this point is called Critical Point and occurs at 225
kg/cm2 (abs) 374.15º C temperature.
11. CRITICAL CONDITION
Definition
“CRITICAL” is a thermodynamic expression
describing the state of a substance beyond
which there is no clear distinction between the
liquid and gaseous phase.
• The critical pressure & temperature for water are
• Pressure = 225.56 Kg / cm2
• Temperature = 374.15° C
13. SUPERCRITICAL BOILER
• Supercritical pressure boiler has no drum and heat
absorbing surface being, in effect, one continuous
tube, hence called ‘once through Supercritical
pressure boilers.’
• The water in boiler is pressurized by Boiler Feed
Pump, sensible heat is added in feed heaters,
economizer and furnace tubes, until water attains
saturation temperature and flashes instantaneously
to dry saturated steam and super heating
commences.
14. SUPERCRITICALTHERMAL CYCLE
ADVANTAGES
• Improvements in plant efficiency by more than 2
%
• Decrease in Coal Consumption
• Reduction in Green House gases.
• Overall reduction in Auxiliary Power
consumption.
• Reduction in requirement of Ash dyke Land &
Consumptive water.
15. INCREASE IN PLANT EFFICIENCY by
SUPER CRITICAL PARAMETERS
1.5
0.9
0.6
3.2
167 bar
538/538’c
250 bar
538/538
250 bar
540/560’c
250 bar
580/600’c
250bar
566/566 ‘c
1
2
3
4
5
6
.
Efficiency Increase
16. COMPARISION OF THERMAL CYCLE
EFFICIENCIES.
• OPEN CYCLE EFFICIENCY - 14.68 %
• WITH CONDENSER - 26.2 %
• WITH SUPER HEAT – 30.75 TO 34.15 %
• WITH REHEAT - 34.2 TO 36.6 %
• WITH SUPER CRITICAL PARAMETERS-
36.0 TO
39.15 %
17. • Efficiency of the cycle= Net W.D/Heat
input
η = 1 - T2
T1
Where ,
T1 = Temp. of heat source
T2 = Temp. of heat sink
19. Steam Theory
• Within the steam generator, fuel and
air are force into the furnace by the
burner.
• There, it burns to produce heat
• From there, the flue gases travel
throughout the boiler.
• The water absorbs the heat, and
eventually absorb enough to
change into a gaseous state -
steam.
• Boiler makers have developed
various designs to squeeze the
most energy out of fuel and to
maximized its transfer to the water.
• To the right is the basic theoretical
design of a modern boiler.
21. MAJOR SECTIONS OF THERMAL POWER PLANT
• Coal Handling
• Boiler & its Auxiliaries
• Turbine & its Auxiliaries
• Cooling Tower & Condenser
• Water Treatment Plant & Water Handling
• Ash Handling System
24. GENERAL SYSTEM DESCRIPTION:
1.Unloading System
Coal Shall received at site through wagons and shall be unloaded by
a. Wagon Tippler.
b. Track Hoppers.
2. Stacking:
When boiler bunkers are full, coal shall be diverted to stockpile through
reversible belt feeder.
The long travel Reversible Stacker cum Reclaimer shall be mounted on yard
conveyers for stacking & reclaiming.
Normally, 2 nos of stock piles will be formed on each side of SCR.
Total 4 nos stockpiles of trapezoidal cross section of height 10m, length
650m & width at base 49m.
The storage capacity is for 15 days at 90 % PLF.
Coal stored shall be (-) 100mm.
25. 3. Screening & Crushing:
Vibrating grizzly screens to separate (-) 25 mm coal before feeding the
coal into crusher.
(-) 100 mm coal size shall be fed to Ring Granular Type Crusher for
crushing coal to (-) 25mm size.
Crushed coal will be fed further into Boiler coal bunkers through belt
conveyers.
4. Reclaiming:
The coal from stock pile shall be reclaimed by bucket wheel reclaimer to
feed onto reversible yard conveyer for conveying into crusher house.
5. Bunker Feeding system:
Crushed coal from crushers shall be discharged onto belt conveyers for
feeding into junction towers. Coal from JT shall be fed into boiler coal
bunkers with the help of travelling trippers.
26. Raw Coal
Belt Conveyor
Primary Screen
Crusher Less than 25MM
Secondary Screen
Belt Conveyor
Coal Bunker
More than 25mm Less than 25mm
29. WHAT IS BOILER
• A BOILER OR STEAM GENERATOR IS A CLOSED
VESSEL IN WHICH STEAM IS GENERATED BY
HEATING THE WATER BY COMBUSTION OF FUEL IN
FURNACE.
• ANY CLOSED VESSEL EXCEEDING 22.75 LITRES IN
CAPACITY WHICH IS USED EXPRESSLY FOR
GENERATING STEAM UNDER PRESSURE AND
INCLUDES ANY MOUNTING OR OTHER FITING
ATTACHED TO SUCH A VESSEL WHICH IS WHOLLY
OR PARTLY UNDER PRESSURE WHEN STEAM IS
SHUT.
30. TYPES OF BOILER
1. MODE OF CIRCULATION OF WORKING FLUID
2. TYPE OF FUEL
3. MODE OF FIRING
4. NATURE OF HEAT SOURCE
5. WORKING PRESSURE
6. SPECIFIC PURPOSE OF UTILISATION
7. MANUFACTURERS TRADE NAME
31. CIRCULATION
• MOTION OF WORKING FLUIDS IN
EVAPORATOR
TYPES CIRCULATION
1. NATURAL CIRCULATION
CIRCULATION BY MEANS OF DENSITY
DIFFERENCE
2. FORCED CIRCULATION
CIRCULATION BY MEANS EXTERNAL
FORCE LIKE PUMPING
33. No. 1
HP Heater
BFBP
MD-BFP
CEP
GSC
No.7AB&8AB
LP Heater
No.5 LP Heater
DEAERATOR
CONDENSER
LPT LPT IPT HPT
No. 2
HP Heater
No. 3
HP Heater
BRCP
LTRH I/L Header
LTRH
ECO I/L Header
LTSH
ECO
No.6 LP Heater
HP
BFWP
CRP
SEPARATOR
SEPARATOR
DRAIN TANK
ROOF TUBE
I/L Header
SH DIV
Panel
FSH
FRH
VERTICAL WATER WALL
SPIRAL WATER
WALL
MSP
HRP
HP-BP
LP-BP
WW LOWER Header
GG
TD-BFP
A B
BA
A B C
34.
35. Steam Turbine
• A steam turbine is a mechanical device
that extracts thermal energy from
pressurized steam, and converts it into
useful mechanical work.
37. HP
T
IPT LPT A LPT B
CPU
GSC
Condensor
(HP) Condenser
(LP)
2
HPH-1HPH-2HPH-3
EXT From
CRH
LPH -5LPH -6
LPH -7A
LPH -7B
LPH -8A
LPH -8B
3
Deaerator
BFB
P
TDBFP
Boiler
CEP
3x50%
2x50%
FCS
5 56 6
2x50%
From Reheater
Economiser
(MD BFP 1x35%)
(MD BFBP
1x35%)
7
8
7
8 8
77
8
1
38. Condenser
Extraction system of A Large Steam
TurbineReheat Steam
HP
Main Steam
Steam for
Reheating
IP
LPLP
HPH HPH/TDBFP LPH
LPH
LPH
39.
40. Condenser
Steam from last stage of
LPT Exhausts on condenser
tube
condensation of steam
takes place
Water collected in hot well
41. Cooling Water System
HOT WATER
COLD WATER
Cold Water
Cooling Tower
CW Pump
Condenser
CCCW
Pump
ACW Pump
Equipments
Heat Exchanger
42. Circulating water scheme
• A circulating water pump house
• Intake channel
• Trash rack
• A chlorination plant
• Traveling water screen
• Connecting pipe line to condensed
• Outlet channel
• A cooling tower
45. Condensate & Feed Water System
Low Pressure Heaters
D/A
Feed Storage Tank
High Pressure HeatersCEP-B
CEP-A
BFPs
HOT
WELL
Boiler
HOT WATER STEAMWARM WATER
A B C
46.
47. Cascade Aerator
Gas Chlorination
Stilling Chamber
Raw Water
Flash Mixer
Flocculator
Tube Settler
Clarified Water Storage Tank
To RO MB
Plant
Poly-electrolyteFeCl3
Alum, Lime
Alum, Lime
Alum, Lime
PRE TREATMENT PLANT
Poly Dosing
Poly Dosing
Poly Dosing
48. Clarifier Soft
Water
Pumps
Clarified
Water
Storage
Tank
Filter Feed
Pumps
CT Make Up
Line
Multi
Grade
Filter
Ultra
Filtration
Micron
Cartridge
Filter
De-
gassifier
RO Feed
Pumps
RO High
Pressure Pumps
RO
Membranes
RO Permit
Tank
MB Feed
Pumps
Mixed Bed
DM Water
Tanks
DM Water
Distribution
Water Flow Diagram (WTP)
49. Water Flow Diagram
(DM Water)
DM Water
Tank
Condensate
Tank
De-Aerator
Boiler Turbine
Water
Cooled
Condenser
50.
51. What is Ash
• Ash is Oxidized form of the mineral matters present in
coal
• Typical ash composition:Sio
2
,Al2O
3
,Fe
2
O
3
,CaO,MgO etc
• Coal with more Sio
2
& Al
2
O
3
, Ash MP > 1400°C
• Coal with more Fe2O
3
, CaO & MgO Ash MP < 1100°C
52. General Description:
Ash Handling System comprises of following sub systems:
1. BOTTOM ASH HANDLING SYSTEM:
A. Bottom Ash Hopper with accessories
B. Bottom Ash Overflow Transfer System
C. Bottom Ash area drain Transfer System
D. Economizer Ash Disposal System
2. FLY ASH HANDLING SYSTEM
A. Vacuum Conveying System
B. Pressure Conveying System
3. SILO UNLOADING SYSTEM
4. WATER SUPPLY SYSTEM
5. ASH SLURRY DISPOSAL SYSTEM
6. HANDLING FACILITIES (CRANES & HOISTS)
7. ASH SLURRY SUMP ACCESSORIES
8. ASH SLURRY TRANSPORT PIPING
9. AIR CONDITIONING & VENTILATION SYSTEM
53. Bottom Ash Handling System
Ash Slurry Sump
AshPond
Ash Slurry
Pumps – 4 sets ASPH
Eco Hopper-6nos
Flushing Appratus-
6nos
Overflow
Tank
Overflow
Pump Settling Tank
Sludge Pumps
Ash Water Sump
AWPH
FAHP-4Nos, BAHP-3Nos, LPW-4Nos
Water
Sludge
Bottom Ash Hopper
Feed Gate
Jet Pump
Clinker Grinder
54. Fly Ash Handling System
Surge Hopper
ESP hoppers-
RCC Silo
Conveying
Compressor-
IA Compressor
Vacuum Pump
Unloading
spout for
Railway
Wagon
Unloading
spout for
Closed
Tanker
Ash
Conditioner
for Open
Truck
for future
Expansion
APH Hopper-
Flushing Apparatus
Air Washer-
Seal Box-
3 cell
Collector
Master D
Pump
Slave D
Pump
Wetting s
Ash Slurry Pump
House
Collector
Tak-
Silo Fluidizing
Blower
From Fly Ash HP Water Pump
58. CONDENSATE & FEED WATER SYSTEM
HOT
WELL
HOT
WELL
CONDENSER
GSC
DRAIN
COOLER
LPH-1 LPH-2
LPH-3
EJECTOR
D/A
D/A FST
HPH-5HPH-6FRS
TO BOILER
LP DOZING
CEP-B
CEP-
A
BFP-A,B,C