CFB Presentation

7/31/2019 CFB Presentation

1/48

CFBC

Circulating Fluidized Bed Combustion


2/48

001 656p

Future utilization of oil and coal in utility and industrial powerstations depend on combustion systems which meet therequirement of an extensive reduction of emission

One solution with economical benefits is:

Circulating Fluidized BedCombustion


3/48

History

141 267p

Two CFB technologies have been developed

One origin was a bubbling bed burning low grade fuels

The other origin were gas/solid reactors for process technology

applications

End of 70ies first applications in coal combustion

Break through

in the 80ies due to environmental legislationTypically 200 mg/m NOX and 200 - 1,000 mg/m SO2 becamemandatory

later due to utilisation of opportunity fuels


4/48

between Fixed Grate, Fluidized Bed,

and Pulverized Firing

Relationships

056 338p

Stoker Firing(Fixed Bed)

Fluidized Bed FiringBFB CFB

Gas

Fuel

Air Ash

Velocity 8 - 10 ft/ sec(2.3 - 3.0 m/ s)

4 - 10 ft/ sec(1.2 - 3.0 m/ s)

Average BedParticle Size

6,000 m

Pulverized Firing(Entrained Bed)

Gas

Fuel

Air

Ash

15 - 33 ft/ sec(4.6 - 10.0 m/ s)

50 m

Gas

Fuel &Sorbent

Air Ash

1,000 m 100 - 300 m

Gas

Fuel &Sorbent

Air Ash

15 - 23 ft/ sec(4.6 - 7.0 m/ s)

Air


5/48

Environmentally friendly

CFB technology generates power :

High SO2 capture

Firing a wide variety of different fuels

Low NOx emissions


6/48

SO2 Capture

CaCO3 --> CaO + CO2

CaO + SO2 + O2 --> Ca SO4

Furnace temperature control isvery critical

Limestone consumption variesenormously with furnace

temperature

Optimum temperature :850 C

850800 900

SO2Capture efficiency

T (C)

SO2 Captureachieved bylimestone injection


7/48

NOx Emissions

- Combustion temperature

- N2 in fuel

- Excess air and staggering1 000800 1 200

NOx

T (C)

NOx Emissions influenced by3 main parameters :


8/48

General Process

Bed temperature

AirAir

Air

Ash

Coal

Flue gas

Temperature maintained by heatpick up in exchange surfaces

Either in furnace

Or in FBHE


9/48

CFB Boilers

1

32

7

4

5

6

8

9


10/48

Main Design Criteria

High bed inventory of fine particles

High recirculation rate

Highly efficient cyclones

External and/or Internal heat exchangers for temperaturecontrol depending upon the application

Concept


11/48

External Heat Exchangers

A very fine tuning of the bed temperature isnecessary

Fuel Analysis leads a small furnace

( Petroleum coke , Anthracites )

Very large electrical capacity CFB

Highly abrasive fuels

Concept

Advisable when :


12/48

Furnace

F B H E

Cyclone

FBHE Design


13/48

FBHE Design

Fluidisationair

Ashes fromcyclonesAshes to

furnace


14/48

Wing Walls

Could be used as Evaporator HP superheater Final reheater

Furnace

Erosion protection

(refratory)

Tube-fin-tube

design

to cyclone


15/48

Omega Panels

View from top

Double SuperOmega Design

Welded Design

Platen heaters within the furnace are a powerfulfeature:

To extract heat for superheating from the furnace

To have a self controlling system for furnace heatextraction (no mechanical control means needed)

To avoid erosion of heating surfaces by installationin the vertical flow area of the furnace and smoothsurface design

First unit has now gathered more than 100 000 hoperation with first platen heater equipment.


16/48

CFD Analysisof Cyclone Performance

006 056px


17/48

(Results from Simulation)

Fractional Collection Efficiency ofCollection Systems

056 287p

0%

20%

40%

60%

80%

100%

120%

0 50 100 150 200 250

d [m]

Collectionefficiency

Cyclone

alternative collection system


18/48

Cyclone Improvement Measures

056 329p

DownwardInclinedInlet Duct

High PerformanceRefractory for Inlet Area

Eccentric VortexFinder Arrangement

Advanced VortexFinder Shape

Second Pass


19/48

(Old and New Cyclone Design)

Particle Size Distributionof Solid Inventory

056 330p

10 m100 1000

Grain size d

0.1

1.0

(%)

10.0

20.030.040.050.0

60.0

70.0

80.0

90.0

99.0

99.9

ResidueR

old cyclone designnew cyclone design


20/48

Maximize fine solid recirculation

Increase carbon burnout as well as limestone utilization

Increasing solid concentration in the upper furnace leads to enhanced heat transfer perfect temperature homogenity

Fine PSD of inventory and thus less erosions

Minimize solids entrained to the backpass and thus less backpass erosion less backpass fouling lower CO generated in the backpass

High Efficient Cyclone Benefits

056 343p


21/48

Cyclone Arrangements

056 352p

< 100 MWel

200 - 300 MWel 300 MW - 400 MWel

100 - 200 MWel

600 MWel


22/48

125 MWe, 250 MWe andBeyond

Class 150 MW

+ +

+ +

++

+ + +

+ + +

Class 350 MW Class 600 MW


23/48

Performance of CFB boilers

EMILE

HUCHET

PROVENCE RED

HILLS

GOLDENBERG TAMUIN

OUTPUTMWe

FUEL

THERMALEFF.

DeSOx

NOxmg/Nm3

125 250 250 115 130

CoalCoal slurry Coal ( 4%S )Pitch Lignite Brown coal Petcoke

> 89 % > 94 % > 93 % > 89 % > 92 %

> 90 % > 97 % > 95 % > 95 % > 90 %

< 200 < 250 < 250 83 % (*)

> 95 % > 95 %

250 215

2002 2003

(*) HHV basis


24/48

Emissions achieved CFBsin Relation to the Fuel Type

058 180p

Fuel Type NOX

mg/mstp, 6 % O2

SO2

mg/mstp, 6 % O2

DesulphurizationEfficiency

%

Anthracite & Anthracite tailings 70 220 80

Petcoke 100 200 97

Slurry 110 140 95

Bituminous Coal 80 200 95

Eastern US Bituminous Coal 60 100 97

High Moisture Lignite 140 200 90

High Sulphur Lignite 160 200 97

Biomass 100 - -


25/48


26/48

Details

Ash Screw Cooler

056 341p

Holo-Flite Screw

Trough Jacket

Heat Exchanger


27/48

Water Cooled Ash Cooler

056 323p

Return to furnace

Ash inlet duct fromfurnace bottom

Conveyor ash

to ash silo

Fluidizing air


28/48

Split Loop Seal

056 232px

Coal

from Cyclone

to Furnace


29/48

Major Recent References:

Utility Boiler

012 188p

Power Station Mlad Boleslav

2 x 50 MW

Energy Supply for VW-Skoda Factory

Technology - CFB

Fuel - BituminousCoal

Capacity t/h 2 x 140

Design Pressure bar 145

Temperature C 535

Commissioning - 1998

Country - Czech Republic

Customer - SKO Energo


30/48

+ 53.0 m

0.0 m

Power Station Cao Ngan,2 x 50 MWLongitudinal Section

012 223p

Live Steam115 bar (design pressure)

538 C66 kg/s (237.6 t/h)

Feedwater223 C

Fuel

Vietnamese Lean CoalCustomer

VINACOAL, Vietnam


31/48

Utility Boiler

012 183p

Major References:

Power Station Ledvice

110 MW

CFB Fired Boiler in Czech Republic

Technology - CFB

Fuel - Brown Coal

Capacity t/h 350


Temperature C 545


Country - CzechRepublic

Customer - CEZ a.s.


32/48

Major References:

Utility Boiler

012 185p

Power Station Emile Huchet

125 MW

CFB Fired Boiler in France

Technology - CFB


Capacity t/h 367


Temperature C 545/540


Country - France

Customer - SODELIF


33/48

Major References:

Utility Boiler

012 187p

Power Station Goldenberg

125 MW

Extra large Furnace due to wet

(up to 60 % water) Brown Coal

Technology - CFB

Fuel - Lignite

Capacity t/h 400


Temperature C 505


Country - Germany

Customer - RWE


34/48

Akrimota, 2 x 125 MW

Boiler with CFB

012 217p

Live Steam138 bar538 C

405 t/hReheater Steam

36 bar537 C375 t/h

Feedwater247 C

FuelHigh SulphurLignite

0.0 m

+ 50.0 m


35/48

Major References:

Utility Boiler

012 184p

Power Station Tamuin

2 x 130 MW

CFB Fired Boilers in Mexico

Technology - CFB

Fuel - Petroleum Coke





Country - Mexico

Customer - SITHE-IPG


36/48

Major References:

Utility Boiler

012 198p

RF#1

2 x 150 MW

CFB Fired Boilers in Taiwan

Technology - CFB

Fuel - Petroleum Coke



Temperature C 541


Country - Taiwan

Customer - FHI


37/48

Major Recent References:

Utility Boiler

012 154p

Power Station an

2 x 160 MW

First CFB Fired Boilers in Turkey

Technology - CFB

Fuel - Lignite





Country - Turkey

Customer - TEAS

+ 56.7 m


38/48

Major References:

Utility Boiler

011 422p

Tonghae Thermal Power Plant

2 x 220 MW

Reheat CFB Boilers in

Republic of Korea

Technology - CFB

Fuel - Anthracite




Commissioning - 1998 and 1999

Country - Republic of Korea

Customer - Tonghae


39/48

Major References:

Utility Boiler

011 424p

Power Station Provence

250 MW

First 250 MW CFB Boilers in the world

Technology - CFB

Fuel - Bituminous Coal

Capacity t/h 700




Country - France

Customer - SOPROLIF


40/48

Major References:

Utility Boiler

011 459p

Power Station Red Hills

2 x 250 MW

Technology - CFB

Fuel - Lignite


Design Pressurebar 203



Country - USA

Customer - Choctaw Generation


41/48

Major References:

Utility Boiler

011 423p

Power Station Guayama

2 x 250 MW

Reheat CFB Boilers in Puerto Rico

Technology - CFB



Design Pressure bar 207 Temperature C 540/540


Country - Puerto Rico

Customer - AES


42/48

3 D Model

250 MW CFB for Indian Lignite

011 475p

Fuels for


43/48

NCV

MJ/kg

Water content

Weight % a.r.

Ash content

Weight % a.r.

Sulphur

% maf

Anthracite 16 8 37

Bituminous coal 19 - 29 7 - 24 3 - 25

Lignite 12 - 18 12 - 42 12 - 26 5.5 - 12Brown coal 8 - 12 35 - 58 1 - 40 1 - 13

Special fuels:

Petcoke < 31.0 < 5 < 1 < 7

Wood chips 12 36 2

Coal slurry 10.5 33 30

Paper sludge 2.4 62 15

Sewage sludge 0.6 73 15

Bark 9 - 16 15 - 50 1 - 3 (20)

Fuels forCirculating Fluidized Beds

056 295p


44/48

Reference Summary

141 269p

Fuels

Coal and ligniteWater content up to 60 %Ash content up to 40 %Sulphur content up to 13 % maf

various opportunity fuels

(coal, slurry, sewage sludge, petcoke, bark, ...)

Water/Steam side

Natural circulationAssisted circulation

Once-through (engineering study)With/without reheat up to 560 C

Capacity

From 70 MWth up to 250 MWel600 MWel under investigation

Advantages of CFB


45/48

Advantages of CFBfor High Sulphur Lignite

Desulphurization of > 97 % achievable

Reduced slagging tendency in the furnace

No slagging due to pyrite of other sulphur components

Reduced fouling in the backpass due to low temperatureand even temperature profile

Higher boiler efficiency Marginal SO3 in flue gas due to SO3 capture by limestone

Therefore, flue gas exit temperature of 140 C or less

056 374p


46/48

Lignite Fired CFB Plants

Sulphur content of 14 % (daf) commercially utilized in CFB

Desulphurization of > 97 % achievable

Special attention must be given to cyclone performance

Equal fuel / air / limestone feeding into the furnace must beensured under all operating conditions

Intensive testing is highly recommended:

mine operation coal analysis with emphasis on type of sulphur

available limestone sources and limestone reactivity

combustion tests give valuable results

Conclusion

056 377p


47/48

Summary

001 673p

CFB technology is well developed todayMore than 300 CFB plants are operating or are under constructionPlants with 250 MW capacity are running since 1995

CFB technology meets environmental requirementsNOX values less than 200 mg/m3 s.t.p. and desulphurizationefficiencies higher than 97 % could be achieved

CFB techhnology is able to burn a wide range of fuelsEspecially high sulphur and/or high ash or high water coals couldbe utilized


48/48

Date post:	05-Apr-2018
Category:	Documents
Upload:	sam
View:	227 times
Download:	3 times

CFB Presentation

Documents