overview of burner tests in vattenfallâ€™s oxyfuel pilot plant

Overview of Burner testsin Vattenfall’s Oxyfuel Pilot Plant

Uwe Burchhardt, Rainer Giering,Gerd WeißVattenfall, BU R&D Projects

2013-09-10

2 | OCC3 – Burner tests in OxPP I U. Burchhardt

Agenda

The electrical ignition burner4

Summary5

Tests and results of different burner types3

Requirements on burners for Air and Oxyfuel2

Overview concept of Oxyfuel Pilot Plant1


Base data and Technology partners

• Start up test operation Sept. 2008

• Until 17.000 operating hours in total,from it 13.200 in Oxyfuel mode,captured CO2 approx. 10.660 t

• CO2 removal rate > 90 %

• High plant availability

• Good CO2 quality for transport, storage and CCU Thermal capacity: 30 MWth

Coal demand: 5.2 t/hInvestment 80 Mio. €Total costs 150 Mio. € Technology partner :


Boiler and Measurement points

Eco 5

SH 1

SH 2

A ir pre-heater

Eco 4

Eco 3

Eco 2

Eco 1

M easurem ent level 1 , +17500

L 8,+11500

L 9,+15500

L 10,+18500

L 11,+21000

Level 12

Level 13

Level 14

SCR 1

SCR 3

SCR 2

Burner

Steam drum

Ash transport

OFA 1 & 2

SCR optional

13m high4x4m cross area

Floor level, +0





M easurem ent level 6 , +10000L 7,

+9000

Eco 5

SH 1

SH 2

A ir pre-heater

Eco 4

Eco 3

Eco 2

Eco 1


L 8,+11500

L 9,+15500

L 10,+18500

L 11,+21000

Level 12

Level 13

Level 14

SCR 1

SCR 3

SCR 2

Burner

Steam drum

Ash transport

OFA 1 & 2

SCR optional

13m high4x4m cross area

Floor level, +0





M easurem ent level 6 , +10000L 7,

+9000

Fron

t wal

l

Left side wall

Right side wall

~100

0~10

50~1

050~

1000

~1000 ~1050 ~1050~1000~1000 ~1050 ~1050~1000

3 2 14

5

67 8 9

FurnaceSoot blower before each super-heater and eco 5

3

2 1

4

2nd draft30 MW burnertop mounted


Direct coal dosage to burner

Combustion behaviour can only be judged in connection with coal dosage


Agenda

Outlook : The electrical ignition burner4

Summary5



Overview of concept for Oxyfuel Pilot Plant1


Requirements on burners

- high range of particle size distribution- Variation to LHV

Flexibility for fuel quality

- Combustion gas: air or O2-mixed flue gas (21%-39%)- Fuel transport gas: air or CO2-rich flue gas- Fuel loading up to 5 kg / kg transport gas

Transport and combustion gas

- Optimal intermixing of coal stream by swirl of secondary airs

- Influence on flame characteristics regarding heat transfer behaviour

Possibility to swirl of secondary airs

- O2 excess in flue gas (downstream boiler) < 4% - compliance emission limits (CO, NOx, dust) - unburned in ash < 2%

High combustion quality: - low excess O2- emissions - unburned

- Ignition within 5 seconds- Hot-, warm- and cold start ability

Fast start ability, stable ignition, stable flame

RequirementsBurner characteristic


Overview of tested burner

2009

2008

Burner 1: comb. Jet-/swirl burner

Burner 3:pure swirl burner

Burner 5: swirl burnerwith pre-mix possibility

Burner 2: pure swirl burner

Burner 4: swirl burneras pre-mixed burner

2010

2011

2012


Overview of constructions

- concentric formation of one core pipe for oxidant supply, one fuel/transport gas and three secondary oxidant cross-sections

- swirl generator located in secondary and tertiary oxidant supply. Option to modify the angle of swirl generator

- Injection of fuel directly into third oxidant supply cross section

Pre-mixed swirl burner

- concentric formation of one core pipe for oxidant supply, one fuel/transport gas and two oxidant cross-sections

- Conduct of flame with a high swirl rate - Flame is short and shows characteristic bell shape

Pure swirl burner

- concentric formation of one core pipe for oxidant supply, one fuel/transport gas and three secondary oxidant cross-sections

- length of flame nearly up to exit of firth path of the boiler

Combined Jet-/swirl burner

CharacteristicsBurner type


Agenda


Summary5





Overview of burner tests

- Flame characteristics and heat transfer- Switch from Air to Oxyfuel operation and back- O2 concentration in combustion air (burner lambda, boiler lambda)- Reduction O2 excess at compliance emission values- Swirl variation- In-flame measurements- Optimization firing behaviour with variation OFA- part load behaviour- different lignite qualities (sulfur, particle size distribution)


Comparison of operational points in Oxyfuel

characteristic diagram for different burner test

20

25

30

35

40

45

2,0 3,0 4,0 5,0 6,0 7,0 8,0

O2 in fluegas (Vol %,f)

O2

in o

xida

nt (i

n %

)

TC 3

TC 4

TC 5

TC 6

TC 7

TC = Test Campagne of burners


Emissions in Oxyfuel: NOx, CO vs. excess O2 (TC 5)

0

100

200

300

400

500

600

700

800

900

1000

0 1 2 3 4 5 6 7 8

Excess O2, vol-% (wet)

CO

& N

Ox,

mg/

Nm

3 (6

% O

2, d

ry)

Oxy24 CO Oxy24 NOx Oxy28 CO Oxy28 NOx

Oxy32 CO Oxy32 NOx Oxy36 CO Oxy36 NOx


O2-Mix: Pre-mixed mode, Expert mode und Hybrid mode

Furnace

BurnerStart burner

2. path

(DeNOx)

3. path

Oxygen

FG-Rec.

Furnace

Burner

2. path

(DeNOx)

3. path

Oxygen

FG-Rec.

Furnace

Burner

2. path

(DeNOx)

3. path

Oxygen

FG-Rec.

Expert modePre-mixed mode Hybrid mode


Comparison of burner operational area on varied operation mode and in respect to emission limits

16

18

20

22

24

26

28

30

32

34

36

1 1,5 2 2,5 3 3,5 4 4,5 5

O2 in flue gas (Vol.-%,w)

O2

in O

xida

nt (

Vol.-

%,w

)pre-mixed Mode Expert-Mode Air operation Hybrid-Mode


Influence of swirl change on flame shape and temperature

Before adjustmentswirl SA1/SA2

After adjustmentswirl SA1/SA2

Furnace camera Thermovisions camera (DURAG) CombTec-Measurement


Overview of burner tests

Variation O2 content 21% to 39%in different burner registerStable operation < 3% O2 excess possible

O2 concentration in combustion air(burner lambda, boiler lambda)Reduction O2 excess at compliance emission values

Swirl of secondary air flows necessary Swirl variation

Optimisation OFA has influence of combustion behaviour (reduce NOx/CO)

Combustion behaviour with variation OFA (staged combustion)

Validation for CFD burner model possibleIn-flame measurements

In general in 20 minutes realizedSwitch from air to Oxyfuel operation and back

Stable flame without pulsation,- Flame shape (volume and length)

Flame characteristics and heat transfer

ResultsBurner tests


Agenda


Summary5





Features of OxyAir Burner 5

Low-NOX-Technology

Load Range 100 % down to 30%

Fuel Load up to 4 kg/kg

Applicable for Oxyfuel and Air Operation Mode

Flame Stabilizer and Swirler for reliable Ignition and stable Flame


Test of ignition by Microwave-Plasmatron

Concept:• Direct Ignition of dried lignite by Microwave Plasmatron• Usage of up to 3 plasma lances for ignition during tests operation• Control of ignition by control box on-site• Supply of external media e.g. power, compressed air and cooling water

Microwave- Plasmatron:• No electrodes that could wear, low afford

of maintenance• Easy construction• Low power consumption for ignition• Technology is in development, currently

no commercial solution available• Limited in size• Due to high temperature of plasma

flame an external cooling is required

Generator

Ignition lance

Ignition flame

Fasteningat burner

© Copyright by Hegwein (Patent pending)

©


Ignition of 30 MW dry lignite burner with plasma lances


Test results electrical Ignition

Successful ignition without preheating of combustion air30 °CWithout

pre-heatingTemperature of combustion air

Optimal position is dependent on burner designPosition of plasma lance

Get more information about ignitionbehaviour after long term depositionin boiler

> 100 StartLong term experience

Successful Ignition with 2 kW el. Load2 kW3 kWel. load for ignition

of plasma lance

Successful Ignition over a wide Range, lowering of start

performance on 10% (3 MW )3 - 15 MW15 MWStart up load of burner

Successful ignition in cold boiler43°CCold boilerBoiler temperature

All major issues of optimization arecarried out with one plasma lance13 - 1Number of plasma lances

CommentsActualTargetCriteria


Agenda


Summary5





Summary and outlook

• Vattenfall cooperated with many technology partners for the burner development for Oxyfuel (5 burners from 4 different manufactures)

• Varified stable ignition and burnout behaviour

• Stable operation with high O2 concentration in oxydant and low O2excess. All emission limits are reached.

• Pre-mixed mode for commercial CCS plant sufficient

• Burner design depends on firing concept

• Electrical ignition burner is an economical alternative

Vattenfall is ready to scale up for a demo plant

Thank you for your attention!

overview of burner tests in vattenfallâ€™s oxyfuel pilot plant

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