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transcript
10.11.2015
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From subcritical and once through CFB steam generators towards 600 MWe USC CFB technology
71st IEA FBC Meeting
Seoul, 5 November 2015
IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
Presentation Summary
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I. Features of advanced CFB technology
II. Once through CFB boilers
III. Pentleg design for large scale CFB
IV. USC CFB demonstration project
V. Summary
IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
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Fuel Impact On Boiler Selection - Introduction
• Fuel choice significantly affects boiler design selection.• The range of heating value, ash, volatiles and moisture content determines the boiler
configuration, fuel handling and combustion systems design, performance and cost. • The environmental requirements coupled with the fuel choice determines specific emission
control systems and further impacts the economics for specific designs.• The level of volatiles fundamentally determines the combustion method driving the need for
greater residence times, e.g. Anthracite requires Downshot and CFB/BFB designs.
30 10 20 30 40 50 60 70 80 90
4500
5500
6500
7500
8500
9500
Volatile %wt
Hea
ting
Valu
e M
J/kg
(dm
mfb
asis
) Anthracite/Petcoke Bituminous/Sub-bituminous Lignite Peat Wood
PC Downshot
PC - Wall or Tangential Firing
CFB/BFB/Grate
3IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
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CFB Integrated Environmental Protection
IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
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Control of combustor temperature through FBHE
Principle:
Bed material flow is used to control combustor temperature
Superheated steam temperature is controlled by attemporator
Principle:
Bed material flow is used to control combustor temperature
Superheated steam temperature is controlled by attemporator
Control of reheat temperature through FBHE
Principle:
Bed material flow is used to control final reheat temperature
Attemporator is used for “fine adjustment” and material protection
Principle:
Bed material flow is used to control final reheat temperature
Attemporator is used for “fine adjustment” and material protection
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Stadtwerke Duisburg AG, FRG, 100 MWe
Stadtwerke Duisburg CFB within 600.000 people City of Duisburg
first CFB applying Benson (once-through) principles!
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Year of Commissioning 1985
Thermal Capacity 226 MWLive Steam 270 t/h
535 / 535 °C145 / 32 bar
Feedwater 234 °C
Design Fuel Bituminous CoalL H V 25,0 MJ/kgAsh 20,0 %Moisture 8,0 %Sulphur 1,4 %
Duisburg OTU CFB Process Flow Diagram
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IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
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Berlin 100 MWe, Germany
IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
Berlin 100 MWe, Germany
Year ofCommissioning 1990
Thermal Capacity 242 MWLive Steam 326 t/h
540 / 540 °C196 / 43 bar
Feedwater 300 °CMin. Load 40 %
Design Fuel Lignite, Subbit.CoalL H V 30,0 MJ/kgAsh 6,7 %Moisture 7,2 %Volatiles 13,0 %Sulphur 1,1 %
first CFB close to 200 bar Benson (once-through) principle!
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Steam CooledMembraneWallType Cyclone
Berlin 100 MWe, Germany
In the Workshop Erection at Site
IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
Typical CFB – Scale up
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Cyclone Arrangements Lower Furnace Design
< 100 MW
100 - 200 MW
100 - 400 MWel
> 400 MWel
Pant-Leg Combustor
200 - 400 MW
IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
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Pantleg design experience in utility scale CFB Boilers
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• Uniform and proper Distribution of– Fuel– Limestone– recirculated Ash
• Perfect Penetration of Combustion Air
– optimum Distribution for large Scale Furnaces
• Symmetrical optimized Flow Pattern
• Contributes to:– lowest Emission Values– best Carbon Burn-out– uniform Flue-Gas Distribution to Cyclones
IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
Pantleg design – CFB 250 Mwe Gardanne France
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IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
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Design range of Doosan Lentjes CFB Boilers
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Applicability range for SC and USC CFB boilers
IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
Spiral tube vs Vertical tube furnace
16IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
Vertical Tube FurnaceSpiral Wound Furnace
Vertical Tubes where Heat flux is lower
Spiral tubes forlower furnace
Burner region Burner region
High fluid mass flux gives high frictional DP and
negative flow characteristic
Vertical tubes forlower furnace
Zone of highestHeat flux
Welded straps tosupport tubes
Self-supportingtubes
Low mass flux designs giveLow frictional DP and
Positive flow characteristic
The spiral tube furnace has been the dominant configuration of once through supercritical boiler designs. However, a vertical tube arrangement makes manufacturing and construction easier and offers advantages for CFB boilers where furnace shapes and circulating solids require a reliable solution.
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Positive flow characteristics of vertical tube furnace
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High water flow rates lead to high dynamic lossesWhen extra heat is applied to a tube or group of tubes, the overall pressure drop increases significantly.
The flows in the affected tubes have to fall to match the overall circuit pressure drop.
Circuits designed with low water flow rates are dominated by static pressure drops
When extra heat is applied the static pressure drop and overall pressure drop fall.
The flows in the affected tubes have to increase to match the overall circuit pressure drop. (= positive flow response)
High mass flow
Static pressure losses
Dynamic pressure losses
Low mass flow
1800 1800 1250 700 700 777100 115 115 100 115 115
High water flow rates lead to high dynamic lossesWhen extra heat is applied to a tube or group of tubes, the overall pressure drop increases significantly.
The flows in the affected tubes have to fall to match the overall circuit pressure drop.
Circuits designed with low water flow rates are dominated by static pressure drops
When extra heat is applied the static pressure drop and overall pressure drop fall.
The flows in the affected tubes have to increase to match the overall circuit pressure drop. (= positive flow response)
High mass flow
Static pressure losses
Dynamic pressure losses
Low mass flow
1800 1800 1250 700 700 777100 115 115 100 115 115
Low mass flux designs offer the possibility of a ‘positive’ flow response.
Low mass flux designs are defined as evaporator designs with mass flux in the range 500 to 1200 kg/m2s at maximum boiler output. Note: ‘positive’ flow response diminishes towards 1200 kg/m2s.
IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
600MWe USC CFB Demonstration Project
Requirement Target ValueUnit Size (MWe gross) 600
Location / Cooling / Arrangement
Coastal / Sea Water cooled, 6 Cyclones
Fuel – Indonesian LRC – GCV (kCal/kg) 4250
Main Steam Temperature (oC) 610Main Steam Pressure (Barg) 280Reheat Steam Temperature (oC) 621
Boiler Thermal Efficiency (%HHV) >85
Boiler Availability (%) >90Outlet SOx (ppm@6%O2) <50Outlet NOx (ppm@6%O2) <50Outlet Dust (ppm@6%O2) <15
18IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
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600MWe USC CFB - Design features
o Scale up of proven pentleg designo 6 pcs highly efficient steam cooled
separatorso High carbon burnouto Furnace width below 30 mo Low mass flux vertical tube design
(550-700 kg/m2s)o „Natural circulation“ safe
characteristic of evaporatoro Optimium combustion temperature
850 Co Controllable FBHEs as final
superheaters and reheaterso Inherently low NOx emissions
IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
Large furnace heat flux distribution – study example
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www.aee-lentjes.de / Name of presentation
IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
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USC CFB Comparable to adequate size of PC unit
USC CFB is more compact than PC (with FGD)
L = 110mW = 45m
H = 70m
•600MW USC PC Boiler (Indonesian Sub-bituminous) Footprint = 5440m2 includes FGD@ 900m2
(Based on Dongbu Green 2x580MW)
600MW USC CFB Reference (Indonesian Sub-bituminous) Design Footprint = 4950m2
IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
CFB more suited to a wide array of fuels and fuel switching.
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0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00 100.00
NC
V [k
J/kg
, as
fire
d]
ballast (ash + moisture) [wt.%, as fired]
DL CFB boilers
wet biomass
dry biomass
oil sanddiscard / high ash coal
PC boiler
lignite
hard coal
Tire-derived fuel (TDF)
sewage sludge
Where fuel switching covers a wide range from high CV world traded bituminous to low cost high ash, high moisture or high slagging coals, CFB offers capex, reliability and fuel saving advantages over PC fired units
IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
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qThe Company is currently scaling up its CFB boiler capability to 600MWe class for demonstration in South Korea with target steam conditions at Ultra-Supercritical levels.
q Integration of USC PC and CFB technologies for better performance and emissions control
qScale up of the combustor and introduction of ‘once through’ vertical furnace tube technology
q 6 to 8 cyclone design foreseen dependent on output, fuel and site conditions
qHigh plant efficiency + value of fuel flexibility (fuel switching)
Summary – Doosan USC CFB development
23IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock
Thank you
damian.goral@doosan.com
IEA FBC Mtg | 05.11.2015 | Seoul | Doosan Lentjes / Doosan Babcock