oxy-firing of fired process heaters: cfd analyses and ......oxy-firing of fired process heaters: cfd...
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Oxy-firing of Fired Process Heaters: CFD Analyses and Comparison with Data 3rd Int’l Oxy-Fuel Combustion Conference, Ponferrada, Spain September 9 – 13, 2013
Jamal Jamaluddin – Shell Global Solutions (US), Inc. Jaime A. Erazo, Jr., Charles E. Baukal, Jr. – John Zink Co., LLC
Presentation Outline
• Project Summary
Background and objectives Description of test furnace system CFD simulation of test furnace, and comparison with data CFD simulation of multi-burner VC and Box heater Summary of simulation results
• Conclusions • Acknowledgement
Project Background and Objectives
• CCP is a partnership of major energy companies, working to advance the technologies that will underpin the deployment of industrial-scale CO2 capture and storage.
• Since 2000, the CCP has undertaken more than 150 projects to improve the understanding of the scientific basis, economic drivers and engineering applications of the CCS technologies. CCP works with government bodies, academics and global research institutes.
• In CCP3, it was decided to confirm the technical feasibility of oxy-firing process heaters and boilers, with the following objectives:
Assess the feasibility of utilizing conventional process heater burners for oxy-firing, through single burner oxy-firing tests in a test furnace.
Perform CFD simulations of test furnace and oxy-fired multi-burner heaters.
• The John Zink Co. was contracted to perform burner testing and CFD simulations for fired process heaters.
Test Furnace
Boiler, Fan, Flue Gas Ductwork
Pictures of the Furnace System
(Pictures courtesy of John Zink Co.)
Sketch of the Test Furnace System
CFD Simulations of the Test Furnace
CFD simulations of the test furnace were performed using ANSYS FLUENT v13.0 simulation code. A user-defined function was used to calculate flue gas emissivities and absorption coefficients under oxy-firing conditions. The following scenarios were simulated:
• Two burners : PSFG and COOLstarTM
• Two fuels : Tulsa Natural Gas and Simulated RFG (50% CH4, 25% H2 and 25% C3H8) • Two firing modes : Air-firing and Oxy-firing
PSFG COOLstarTM
Flame Shape (PSFG): Air- and Oxy-Fired TNG
Air-firing Oxy-firing
Air-firing Oxy-firing
Heat Flux Profiles (PSFG): Air- and Oxy-Fired TNG
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Heat Flux - Normalized
Heat Flux Profile, NormalizedPSFG- TNG Air Case
Test PSFG TNG-Air CFD PSFG TNG-Air
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Heat Flux - Normalized
Heat Flux Profile, NormalizedPSFG- TNG Oxy Case
Test COOLstar TNG-Oxy CFD COOLstar TNG-Oxy
Incident Heat Flux: Air-Fired TNG Incident Heat Flux: Oxy-Fired TNG
Heat Flux Profiles (PSFG): Air- and Oxy-Fired RFG
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Heat Flux - Normalized
Heat Flux Profile, NormalizedPSFG - RFG Air Case
Test PSFG RFG-Air CFD PSFG RFG-Air
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Heat Flux - Normalized
Heat Flux Profile, NormalizedPSFG - RFG Oxy Case
Test PSFG RFG-Oxy CFD PSFG RFG-Oxy
Incident Heat Flux: Air-Fired RFG
Incident Heat Flux: Oxy-Fired RFG
Flame Shape (COOLstarTM): Air- and Oxy-Fired TNG
Oxy-firing Air-firing
Air-firing Oxy-firing
Heat Flux Profiles (COOLstarTM): TNG Firing
Incident Heat Flux: Air-Fired TNG Incident Heat Flux: Oxy-Fired TNG
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50% 55% 60% 65% 70% 75% 80% 85% 90% 95% 100%
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Heat Flux - Normalized
Heat Flux Profile, NormalizedCOOLstar - TNG-Air Case
Test COOLstar TNG-Air CFD COOLstar TNG-Air
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50% 55% 60% 65% 70% 75% 80% 85% 90% 95% 100%
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Heat Flux - Normalized
Heat Flux Profile, Normalized COOLstar - TNG-Oxy Case
Test COOLstar TNG-Oxy CFD COOLstar TNG-Oxy
Heat Flux Profiles (COOLstarTM): RFG Firing
Incident Heat Flux: Air-Fired RFG Incident Heat Flux: Oxy-Fired RFG
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Heat Flux - Normalized
Heat Flux Profile, NormalizedCOOLstar - RFG Air Case
Test COOLstar RFG-Air CFD COOLstar RFG-Air
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Heat Flux - Normalized
Heat Flux Profile, NormalizedCOOLstar - RFG Oxy Case
Test COOLstar RFG-Oxy CFD COOLstar RFG-Oxy
General Arrangement Drgs: VC and Cabin Heaters
Vertical-Cylindrical Heater Cabin-Style Heater
Burner Arangement: VC Heater
PSFG Burners in VC Heater COOLstarTM Burners in VC Heater
Burner Arrangement: Cabin Heater
PSFG Burners in Cabin Heater COOLstarTM Burners in Cabin Heater
Flame Shape (VC Heater): Air- and Oxy-Firing
PSFG burner firing TNG
PSFG burner firing RFG
Flame Shape (VC Heater): Air- and Oxy-Firing
COOLstarTM burner firing TNG
COOLstarTM burner firing RFG
Flame Shape (Cabin Heater): Air- and Oxy-Firing
PSFG burner firing TNG
PSFG burner firing RFG
Flame Shape (Cabin Heater): Air- and Oxy-Firing
COOLstarTM burner firing TNG
COOLstarTM burner firing RFG
Summary of Simulation Results
Parameter Firing Condition
FRNC-5 Prediction
CFD Result (TNG)
CFD Result (RFG)
Bridge-wall Temperature (F)
Air-firing 1465 1455 1461
Oxy-firing 1404 1423 1434
Radiant Efficiency (%)
Air-firing 55 52.7 50
Oxy-firing
67.7 61.9 64.5
Conclusions
• The flame shape and size, as well as temperature and heat flux profiles, predicted by the CFD model agreed reasonably well with data collected in the test furnace.
• The CFD simulations closely matched the heater bridge-wall temperatures and overall efficiencies previously calculated by FRNC-5 (heater deign model).
• CFD simulations predicted significant flame merging for both air- and oxy-firing using the COOLstarTM burner in a vertical cylindrical heater, while these phenomena were less evident for the PSFG burner. These trends are thought to be the effect of imbalance in flue gas re-circulation pattern within the firebox.
• No flame distortion is predicted for either burner in a cabin-style heater. The flames sizes are slightly smaller for oxy-firing, compared to the air-fired case.
• The simulations show that heater performance similar to air-fired
operation can be achieved when oxy-firing is employed.
References and Acknowledgements
References
• J. Jamaluddin, C. Lowe, N. Brancaccio, J. Erazo, C. Baukal, Jr. and R. Patel, “Oxy-Firing Tests in a Simulated Process Heater”, paper presented at the 2012 Annual Meeting of the AFRC, Salt Lake City, Utah (September, 2012).
• J. Jamaluddin, C. Lowe, N. Brancaccio, J. Erazo, and C. Baukal, Jr., “Technology Assessment of Oxy-Firing of Process Burners”, paper presented at the 2012 GHGT Conference, Kyoto, Japan (November, 2012).
Acknowledgements
The authors wish to thank the CO2 Capture Project for their guidance and financial support.