Development of High Efficiency CFB Technology to Provide Flexible

Air/Oxy Operation for Power Plant with CCS

FLEXI BURN CFB

WP2: Development of design tools

2nd Project Workshop, 6th February 2013, Ponferrada

WP2: Development of design tools

2

Comparison of air-

and oxy-firing

Development of

design tools

Boiler design

and performance

Power plant integration,

optimization

and economics

Feasibility and readiness for the utilization of

the technology within different regions in EU

WP1

WP2

WP4 WP5

WP6

Technology demonstration and

background for the commercial

scale design process

Supporting R&D

work

Viable boiler design Viable power plant

WP7: Coordination and dissemination

Demonstration tests

at large pilot unit

and commercial

scale air fired unit

WP3

WP2 Main objectives and tasks

• Task 2.1, Pre-analysis and transfer of test run results of a 1 MW CFB pilot plant (FWEOY, ENDESA)

– Model based analysis of the test data

• Task 2.2, Extension of 1D and 3D models for FLEXI-BURN CFB modeling (FWEOY, LUT)

– Implementation of the sub-models developed in WP1 in 1D and 3D models

– Further development of the 3D model structure and implementation of heat transfer model within fluidized suspensions in 3D model

– Application of multi-phase CFD studies for development of design models

• Task 2.3, Boiler modeling and validation (steady-state) (LUT, FWEOY)

– Validation with test data from WP3

• Task 2.4, Dynamic boiler model development (FWEOY, LUT)

– Dynamic model / module development for FLEXI BURN CFB boiler system, building on existing air-fired models

3

To develop and validate design tools based on bench scale and small

pilot scale experimental results available from WP1 and other projects.

To validate design tools for the boiler and its integration with the plant

components including air separation unit (ASU) and CO2 compression

and purification (CPU).

Task 2.1: Pre-analysis and transfer of test run results of a 1 MW CFB pilot plant

Partners: FWEOY, ENDESA

Test program at CanmetENERGY, Ottawa

Test summary:

• Phase I: Validation test 9/10 2009

• Phase II: Actual test program 1.-8.2010

Statistic (Phase I+ Phase II): • 15 test weeks

• Runs: 88 of which

• 35 in air combustion

• 53 in oxy combustion

• Duration of a steady run:

– 6-8 hours

Task 2.2, Extension of 1D and 3D models for FLEXI BURN CFB modelling

Partners: FWOY, LUT

Development of 1D CFB boiler model for oxy combustion (FWEOY)

• 1D CFB furnace model is one of the core modules in the FWOY´s boiler design software

• 1D furnace model is comprised of several sub-routines simulating process phenomena in combustion and CFB hot loop

• Emission models

• The oxy combustion features were implemented in the model (e.g. gas properties for oxidant and flue gas, recirculating flue gas for oxygen mixing, etc.)

• Validation of the 1D CFB furnace model with test data

Extension of 3D model for FLEXI BURN CFB modeling

• 3D model simulates the furnace process

– Furnace divided to control volumes

– Boundary conditions include all the different feeds (e.g. fuels, gas feeds) and thermal conditions at walls.

– Separate models for separators and Intrex units

• The submodels, which were developed in WP1 were implemented to the 3D-model in WP2.

• In addition, several improvements to increase the robustness of the code and the calculation speed.

Separator(s)

- separation eff.

- heat transfer

- reactions

Heat transfer

to walls and

internal

surfaces

Fluidization gas

Inlet sources

- sec. gas

- fuel

- limestone

- sand

External heat

exchangers

- heat transfer

- reactions

Flue gas,

fly ash

Exchange of

gas / solids

Solids to

furnace

Gas, solids

Combustion,

gasification &

other reactions

Solids

Bottom ash

Fluidization

gas

Recirculation of flue gas / fly ash

Solids

Gas

Task 2.3, Boiler modeling and validation (steady-state)

Partners: LUT, FWEOY

Development path from small to large scale

M

Oxy-CFB-300 (37 m)

Bench scale (0.6 m) VTT pilot (0.1 MWth, 8 m)

CIUDEN TDP (15 MWth, 20 m)

CANMET pilot (1 MWth)

Validation of the 1D CFB furnace model (Solids mass balance)

• Measured furnace vertical temperature, pressure and oxygen profiles

• Solid material sampling: fuel, limestone, bottom ash, fly ash and circulating material

• Fuel and limestone flow, composition and PSD

• Ash balance: bottom ash and fly ash weighing, chemical characterization of ashes, PSD

• Circulating solids: composition, PSD

Measured furnace temperature profile (70/30 w-% anthracite/petcoke mix. =Blend1)

Measured furnace pressure profile

(70/30 w-% anthracite/petcoke mix. =Blend1)

Validation of the 1D CFB furnace model (Solids mass balance, material and energy balance)

(Anthracite/petcoke blend)

• Solids density profile

• FW´s boiler design software is used modelling of material and energy balance and to verify the model accuracy with the test data

Modelled vs. measured fuel flow Modelled vs. measured ash flow

Modelled vs. measured solids

density

Modelled vs. measured temperature profile

Task 2.3: Boiler modeling and validation Modelling of CIUDEN TDP by 3D-model

• Different model versions tested. Examples below.

• Different fuel mixtures and operating conditions.

• The new model approach (Case 2) simulates the furnace process better.

Model mesh

20 000 cells Model vs. measurements

Task 2.4, Dynamic boiler model development

Partners: FWEOY, LUT

Dynamic boiler model development

• Dynamic model / module development for FLEXI BURN CFB boiler system, building on existing air-fired models validated for large CFB units (e.g. Lagisza 460 MWe SC-OUT CFB)

• Sub-models: furnace, water/steam path, flue gas path, combustion gas preparation (mixing recirculated flue gas and oxygen);

• The model excludes the ASU, CPU and the BOP (balance of plant) systems.

• The model is capable to perform between 40% and 100% BMCR.

• The main control loops, unit master control, boiler control and steam temperature control loops are applied.

• The 1-D dynamic hot-loop model (Simulink) is integrated into the Apros model as dll module.

• Both steady-state and dynamic performances of the 300 MWe Flexi-Burn CFB boiler have been investigated in Apross simulation environment.

Large-scale boiler model in Apros

Integrated 1-D dynamic CFB hot-loop model

Validation and simulations

• 1D dynamic model validation based on tests at CIUDEN TDP and VTT pilot.

• Large scale model for Oxy-CFB-300.

Measurement vs. simulation

Simulated load changes in air and oxy mode

Conclusions

• An extensive database of experimental data in different scales of test facilities has been created to support the development process models and design tools and their validation:

– 1D and 3D CFB models,

– emission models,

– 1D dynamic models & Apros CFB boiler simulation model

• Special attention in results evaluation has been in the design fuel of the 300 MWe Compostilla boiler i.e. 70/30 w-% anthracite/petcoke mixture:

• Evaluation of the CIUDEN test data has confirmed the results from smaller pilots and, hence, produced valuable results for scale-up to 300 MWe size.

Thank You

Acknowledgements: The research leading to these results has received funding from the European Community’s

Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 239188.