overview of supercritical thermal power plant

1. Welcome

2. OVER VIEW OF 2*800 MW SRI
DAMODARAM SANJEEVAIAH THERMAL
POWER STATION

3. contents

5. Location Nellore, Andhra
Pradesh
Status Under Construction
Construction cost 8432/- crores
Owner(s) APPDCL
Operator(s) APGENCO
Primary fuel Coal-fired
Units operational 1*800 MW
Name plate capacity 1600 MW

7. Fuel
• Domestic washed coal & imported coal in 70:30 ratio with
27.5% Ash
• GCV(gross calorific value) of 4,800 kCal/kg shall be used as a
fuel during normal operation
• LDO(light diesel oil) as well as HFO(heavy fuel oil) shall be
used as a startup as well as support fuel

8. Fuel
• Coal is mined from Kalinga ghat , Talcher Coalfield, Angul
district , Orissa
• shipped to krishnapatnam port by MGR trains and Coal
barges and loaded to conveyer belt by stacker

9. stacker
Fuel

10. Pulverisation
 Fine powder of coal ,grinded by millers is fed into
furnace by hot air(primary air).
 Secondary air is fed into furnace to complete
combustion.
 Amount of primary air depends on load(>3%)
 High thermal efficiency
 Better control over load fluctuations
 Free from clinker and slagging troubles

11. MILLS
A Mill is a mechanical device for the grinding coal upto
desired fineness
There are 6 mills , located adjacent to furnace at ‘0’ M level

12. Furnace
• Tangential firing-flame envelope rotates ensuring through
mixing within the furnace
• Heat energy is transferred through radiation (80%) and
convection(20%).

13. Furnace
• Heat generating rates of 1.5x 106
kJ/m3
/hr can be
achieved
• Maximum amount of coal can be achieved with min
. space and time
• Through tip(vertical arc) temperature can be varied
upto 1000
c
• So constant superheat temperature can be
maintained

14. Ash handling plant
• Ash generated is about 30-40%of fuel consumption.
• Must be removed time to time
• due to hotness , difficult to handle

15. Bottom ash removal system
• Non combustible residue of combustion of furnace is
bottom ash
• Bottom ash falls from furnace to ash sluice trench
and discarded to ash pond after mixing with water

16. Electrostatic precipitator
An ESP is a filtration device that removes fine
particles from a flowing gas using the force of an induce
electrostatic charge minimally impeding the flow of
gases through the unit.

17. Electrostatic precipitator
• Dirt particles are negatively charged
• They are attracted to the positively charged plates
and stick there
• From time to time, the collecting plates are shaken to
empty away the soot (rapping mechanism)

18. ESP

19. • collected in ESP hoppers
• We have 8X8 hoppers
Fly ash removal
system

20. Fly ash removal system
• Pneumatically send to silo and then to trucks
• Fly ash is used in
1.production of cement clinkers, concrete, ceilings
2.structural fills , agricultural purposes, floor etc

21. Water treatment plant
• Through ion exchange process , RO and filtration by
resin beds water is demineralised

22. Water treatment plant

23. DEMINERALISED(DM) Water
parameter value
Conductivity <0.2 μS / Cm at 25 Deg.C
pH value 9 - 10 at 25 Deg.c
Total silica <0.02 ppm as SiO2
Iron as Fe Not detectable as per ASTM
methods
Free CO2 ppm (as CO2 ) “
Total Hardness “

24. Sea water
PARAMETERS AS VALUE
pH - 7.6
Turbidity NTU 10
P-alk / M- alk as CaCO3 ppm 98
Ca hardness as CaCO3 ppm 1100
Mg hardness as CaCO3 ppm 5050
Chloride as Cl % 1.89
Silica SiO2 ppm 3.8

25. Babcock and Wilcox boiler
• Boiler is a device for generating steam for power, processing
and heating purposes
• Supercritical boiler operates above critical point

27. Supercritical boiler
• steam turbine efficiency improves significantly compared to
the typical subcritical cycle.
• The load change rate capability of the system is not
restricted by the turbine
• Steam temperature at the inlet and outlet of the reheater is
nearly constant over a wide load range
• The boiler feedwater pump power is significantly reduced at
lower loads
• Short startup times

28. Classification Supercritical boiler

29. UP

30. Universal Pressure (UP®
) boiler.
• The original B&W boiler for supercritical applications was the
Universal Pressure (UP®
) boiler.
• These boilers, nine of which are in operation, are among the largest
capacity fossil fuel boilers in the world.
SPECIFICATIONS
• Capacity, steam output:
700,000 lb/h (90 kg/s)
• Pressure:
Subcritical, usually 1800 to 2400 psi throttle pressure with 5%
overpressure capability.
• Superheater and reheater outlet temperatures:
538 to 566C
• Fuel:Pulverized coal.

31. SWUP

32. Spiral Wound Universal Pressure
Boiler
• Designed for both base load and variable pressure load cycling
operation as well as on-off cycling operation.
• The unique feature of this boiler, compared to other boilers, is that
the tubes in the furnace, from the lower furnace inlet headers to a
location near the furnace arch, are wound around the furnace
circumference rather than being vertical.
• This design allows the fluid in the tubes to pass through the various
heat flux zones around the furnace providing a more uniform outlet
enthalpy.

33. Spiral Wound Universal Pressure
Boiler
SPECIFICATIONS
• Capacity, steam output:
From 2,000,000 lb/h (252 kg/s) to more than 10,000,000
lb/h (1260 kg/s).
• Operating pressure:
3500 psi (24.1 MPa) throttle pressure with 5%
overpressure; higher pressures available.
• Superheater steam temperatures:
As required, currently in the 595C range.
• Fuel:Pulverized coal. ​

34. Vertical Tube Universal Pressure
Boiler
• A once-through boiler, applied to systems with a capacity
of 400 MW or larger
SPECIFICATIONS
• Capacity, steam output:
252 kg/s to more than 1260 kg/s.
• Operating pressure:
3500 psi throttle pressure with 5% overpressure; higher
pressures available.
• Superheater steam temperatures:
currently in the 595C range.
• Fuel:Pulverized coal. ​

35. BOILER
Main steam flow..........2600 T/hr
SH steam press..............255 kg/cm2 (g)
SH steam temp..............568° C
Feedwater temp............307° C
RH steam flow...............2052 T/hr
RH steam press.............57.8 kg/cm2 (g)
RH steam temp..............596° C
Height............................

36. BOILER
Fuel Design Range
GCV, kCal/kg 4800 4000-5000
Moisture, % 9.5 6.0-20.0
Ash, % 27.5 25.0-34.0
Volatile matter,% 28.5 20.0-33.0
Fixed carbon,% 34.5 24.0-40.0
HGI 50 5-55

37. Boiler accessories
Economizer
Waste heat of the flue gases is utilized for heating the feed
water
Air Pre-heater
Transfers heat from flue gases to primary/secondary
Air by means of rotating heating surface elements
Super heater
Increases the temperature of the steam above its saturation
point

38. Boiler accessories
P.A.Fan (two per unit-50% capacity each)
designed for handling atmospheric air upto a
temperature of 500
c
F.D.Fan (two per unit-50% capacity each)
designed for handling secondary air for the boiler
I.D.Fan (two per unit-50% capacity each)
1. located between ESP and chimney.
2.used for sucking flue gas from furnace

39. Boiler accessories
• SCR technology
1.Converts NOX into N2 and water .
2.Anhydrous/aqueous NH3 or urea is added to stream of
………flue gases and is adsorbed onto a catalyst
4NO + 4NH3+ O2 → 4N2 + 6H2O
3.They reduce NOx by 70-95%

40. SCR
• SCR incorporating Ammonia Injection Grid (AGI) and
IsoSwirl Mixing system
economizer

41. Steam Turbine
• Being a form of engine , requires in order to function a
suitable working fluid a source of high grade energy and
sink of low grade energy
Low presure module of sft 100 alstom

42. Steam Turbine
• Greater heat drop
• Absence of internal lubrication(no filters)
• Develops many times the power compared to reciprocating
engines
3 stage turbine
(tandem compounded)

43. Steam Turbine
• The cylinder(stator) contains fixed blades , vanes and
nozzles that direct steam into moving blades(rotor)
• The rotor are completely enclosed in a alloy steel outer case
(one capable of withstanding high pressures and
temperatures).

44. Steam Turbine
• The rotor of large steam turbine consists of large ,
intermediate and low pressure sections.
• change in direction of motion gives rise to a change of
momentum or force
• this is driving force of the primemover
Four Cylinder Turbines

45. Turbine name plate details
Output 800,000kW
Speed 3000rpm
HP STEAM PRESS. 24.2MPa(a)
HP STEAM TEMP 565 deg

47. Cooling tower(hyperbolic)
• Required when positive control of temperature is
required
• Rate of evaporation of water depends on
1 amount of water surface area exposed
2 time of exposure and R .H of air
3 (inlet air WBT-water inlet temperature)

48. Cooling tower(hyperbolic)
• It is necessary to precool the hot water from condenser So
(Two-Ts ) Is high
• Vacuum at condenser can be maintained
• It comprises of 30% of budget
• Due to large base , withstands hurricanes
• No fanes are needed
• Chimney shape creates it own draught

49. Cooling tower(hyperbolic)
• Height = Plan------circular
• Diameter= Profile---hyperbolic
• (inside)

50. Cooling tower(hyperbolic)
• Steel reinforced concrete structure
• Mostly hollow inside
• Bottom is 10m above air-intake
• Force causing air to flow
F=H(w0-wi)

51. Active power – 604.35MW
Reactive power – 46.35MVAR
Generator kV : R-Y – 24.32kV
: Y-B – 24.32kV
: B-R – 24.23kV
Generator Amps : R-ph – 14.14kA
: Y-ph – 14.33kA
: B-ph – 14.61kA
Frequency : 49.97Hz
P.F : 1.00
GENERATOR PARAMETERS

52. FIELD PARAMETERS
• Field voltage : 288.33V
• Field current : 3452.6A
• Rotor temperature : 65.13’c
• POS 90R(AUTO) : 101.36%
• POS 70E(MANUAL) : 147.89%

53. Fig. 19 Switchyard
 Switchyard is a part of electrical generation, transmission and distribution
system.
 Switchyard generally have circuit breakers, CT’s ,PT’s, Bus bars,
Transformers, Protection control equipments, Switches etc.,.

54. Fig. 20 Circuit Breaker
 Circuit breaker: A circuit breaker is an automatically operated electrical
switch designed to protect an electrical current from damage caused by
overload or short circuit. The basic function of CB is to detect a fault
condition and, by interrupting continuity to immediately discontinue
electrical flow.

55. Fig. 21 Lightning arrester
 Insulators: The insulators provide necessary insulation between line
conductors and supports and thus prevent any leakage current from
conductors to earth.
 Lightning Arrester: It is a device used on electrical power systems and
telecommunication systems to protect insulation and conductors of the
system from the damaging effects of lightning.

56. Fig. 22 Voltage transformer
 Voltage transformer: These are necessary for isolating the protection,
control and measurement equipment from the high voltages of the power
system. These are used to supply appropriate values of voltages to the
equipment.

57. Fig. 23 Current transformer
 Current transformer: To feed the current circuits in protection systems
employing secondary relays current transformers are used.
 Bus coupler: Two different bus sections of two different power
transformers are connected by means of a bus coupler.
 Relay: It gives a tripping signal in case of any irregularity or faults.

58. Thank you
by
HARSHA.S