Post on 03-Jan-2020
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
Super - Critical Boiler Technology
By
C.JayadevanGeneral Manager
Engineering/Fossil BoilersBharat Heavy Electricals ltd., Tiruchirappalli
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
Indian Power Scenario
Installed Generation Capacity – current : 130 000 MW
Capacity Requirement by 2012 : 200 000 MW
Capacity Addition – XI plan programme : 78 000 MW
New Capacity Additions include
Ultra Mega Power Plants (UMPP) – Capacity 4000MW each
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
Market Requirements
Low cost of generation Minimum emission of PollutantsSuitability for different quality of fuelSuitability for differing modes of operation/ grid conditionsHigh Reliability & AvailabilityIncreased use of IT Lowest life cycle cost Life Extension of Power Plants & capacity upgradesHigher size UnitsShorter Delivery time
Bharat Heavy Electricals Limited TIRUCHIRAPALLI
Presentation to CII, JULY 2004
Power Plant Equipment Manufacturers to respond by
Upgrading the technologyImproving the efficiency Reducing the cost
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
Major share of the current energy produced from fossil fuels. Dependence on petroleum fuels reduced world overCoal to continue as mainstay of power generation• abundant availability• relatively lower cost • maturity level of technology options
Energy Options
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
Boiler Technology - Advances in the last Century
SizeSteam ConditionsMaterialsControls & InstrumentationEfficiencyAvailability& ReliabilitySafetyOperational Ease
High Pressure Boilers Vital Component of Coal based Power Generation
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
Boile
r Cap
acity
in M
W
2 10 M W To w e r Typ e
Y e a r1960 1970 1980
200 M W
Ta n g e n tia l F irin g110 M W
0
100
W a ll F irin g60 M W
120 M W
200
300
210 M W
20001990 2010
250 M W
C o n tro lle dC irc u la tio n
500 M W
400
500
600
O n c e Th ro '500 M W
Growth of Unit Size in India
660MW –800 MW sizes being inducted
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
Steam Power plant efficiency increases with increase in steam pressure and temperature.
Power plant Cycles operating above critical pressure (221.2 bar) are classified as Supercritical cycles
With higher cycle efficiency, the supercritical cycle offers the advantage of‘burn less fuel for the same output’ and lower emission.
Supercritical Cycles
Lesser Pollutants – SOX , NOX & CO2
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
2.0
1.5
0.4
0.7
2.0
7.2 %
Turbine Efficiency
Condenser Pressure
Process Optimisation
Steam Parameters
Feed Water Temperature
(FWT, feed heater arrangement)
0.6 Measures on Steam generator
240
- 280
bar
ev
opor
ator
pre
ssur
e55
50
45
40
35
BHEL CC+ Units
Effic
ienc
y, %
20001980 19901960301950 1970
Year
250
bar /
550
°C /
570
°C26
0 ba
r / 5
80 °C
/ 6
00 °C
280
bar /
600
°C /
620
°CBasis 38 %
175
bar /
540
°C /
540
°C
Efficiency Development of power plants in Europe
Efficiency Improvement of Steam power plants
Source: VGB Power Tech 11/2003
Heat Rate Improvement
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
Heat Rate ImprovementSteam Parameters Vs Cycle Efficiency
300241
175 538 / 538
538 / 566
566 / 566
580 / 600600 / 620
6.775.79
3.74
5.744.81
2.764.26
3.44
1.47
3.372.64
0.75
2.421.78
00
1
2
3
4
5
6
7
8
9
10
HP / RH outlet temperature [deg. C]Pressure [bar]
Increase of efficiency [%]
Cycle efficiency with :175 bar and 538/ 538 ºC = 38.0 % (BASE)241 bar and 538/ 566 ºC = 38.0 x 1.0264 = 39%
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
Station Cap
(MW)
Units(No.x MW)
MS Pressure (kg/cm2)
MS/RH Temp 0C
Efficiency (%)
Coal Consumption
(MMT/Yr)
CO2Emissions (MMT/Yr)
4000 8x500 169 538/538 38.6 15.61 22.90
4000 5x800 246 566/593 40.24 14.98 21.97
Environmental Benefits
Source : CEA
Savings in Coal consumed : 0.63 MMT/Yr (about 4% Saving)Savings in CO2 emissions : 0.93 MMT/Yr
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
Super-critical cyclesfor
Thermal Power Generation
Higher cycle efficiency for :
Conservation of fuel resourcesReduction of Pollutants - SOX & NOX
Reduction in CO2 emission Better economy in power generation where fuel costs are high and pollution control requirements are stringent
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
Population of 800 to 1000 MW Unitsinstalled worldwide
USA Japan Russia Germany South Korea China Ukrai
neUzbekis
tan
35 21 19 5 3 3 2 1
Total Units = 89
Coal Fired = 54
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
Steam Parameters - commonly used:
MS Pressure : 247 ata
MS Temperature : 565 OC
RH Temperature : 593 OC
Power plants with Ultra Supercritical steam parameters 350 bar / 700 OC / 700 OC and Net efficiency 50%
under development
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
DRUM TYPE Vs ONCE THRU’ BOILERS
Drum Type
Subcritical Pressure
Once thru
Supercritical pressure
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
VERTICAL TYPE
SPIRAL TYPE
Supercritical Boiler Supercritical Boiler Furnace Wall ArrangementFurnace Wall Arrangement
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
Supercritical Boilers – demands on materials
Demanding service conditions - in terms of sizes, steam conditions, operating requirements etc.
Super critical pressure and the high temperatures stress the boiler components at a high level.
Choice of materials - prime importance with higher steam parameters.
Realising higher steam parameters dependent, on the availability of materials to withstand the
demanding service conditions.
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
Strength to resist rupture at design condition
Fatigue strength to withstand cycling stresses
Ability to resist stress concentrations
Resistance to oxidation,corrosion and erosion
Ability to withstand damaging metallurgical changes during operation
Ease of fabrication
Ease of field construction and maintenance
Physical properties to minimise thermal stresses
Materials for Supercritical Boilers - Properties
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
Materials for Supercritical Boilers
New materials developed in the last two decades to suit high steam parameters
Optimised to achieve greater long-term rupture strength, improved resistance to high temperature corrosion and lower oxide film growth.
Bridge the gap between the ferritic steels and austenitic steels - make the boilers economically viable.
New Materials in use/ under evaluationT92/P92, T23/P23, Super 304H , TP 347HFG , Alloy 617, AC66,
Esshete 1250, HR 3C, NF 709, Incoclad 671, Alloy 617
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
Coal Quality Impact on Boiler Economics & Performance
Indian coals - generally high ash , low calorific value - Warrants bigger equipment -boilers, auxiliaries, coal & ash handling systems
- Increased maintenanceWashed coal / imported colas also now being used by some UtilitiesBoiler design for firing a wide range of coals – increase in cost & likely compromise on performance Close band of properties - improves the boiler performance and reduces the overall cost of power generation. Use of consistent quality better coals/ washed Indian coals/blending with imported coals to achieve close band
Bharat Heavy Electricals Limited, Tiruchirapalli
SC Boiler Technology : 11th Dec 2007
Technologies - to be targeted at achieving higher efficiency and cost effectiveness
Coal based thermal power generation will continue to be the mainstay
Pulverised coal firing – ahead in technical development and operational experience over new technologies
Supercritical technology
facilitate use of coal in economic & eco-friendly mannerthe technology of future in India for large capacity units.
Conclusion
Boiler Manufacturers & Utilities to make use of the boiler technology
in the most efficient and environmentally friendly manner
Bharat Heavy Electricals Ltd; Tiruchirappalli