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Research Papers

Optical Measurements of a Lower Calorific Values-Combustor Operated in a Micro Gas Turbine With Various Fuel Compositions

[+] Author and Article Information
Timo Zornek

German Aerospace Center (DLR),
Institute of Combustion Technology,
Pfaffenwaldring 38-40,
Stuttgart 70569, Germany
e-mail: timo.zornek@dlr.de

Thomas Mosbach, Manfred Aigner

German Aerospace Center (DLR),
Institute of Combustion Technology,
Pfaffenwaldring 38-40,
Stuttgart 70569, Germany

1Corresponding author.

Manuscript received June 26, 2018; final manuscript received July 10, 2018; published online December 7, 2018. Editor: Jerzy T. Sawicki.

J. Eng. Gas Turbines Power 141(4), 041032 (Dec 07, 2018) (7 pages) Paper No: GTP-18-1375; doi: 10.1115/1.4040908 History: Received June 26, 2018; Revised July 10, 2018

In a recent joint research project, a new FLOX®-combustion system was developed to couple a fixed-bed gasifier with a micro gas turbine (MGT). Product gases from biomass gasification exhibit low calorific values and varying compositions of mainly H2, CO, CO2, N2, and CH4. Furthermore, combustion characteristics differ significantly compared to the commonly used natural gas. As the FLOX-technology is considered as efficient and fuel-flexible featuring low emissions of hazardous pollutants, the design of the lower calorific value (LCV) combustor is based on it. It contains a two-staged combustor consisting of a jet-stabilized main stage adapted from the FLOX-concept combined with a swirl stabilized pilot stage. The combustor was operated in a Turbec T100 test rig using an optically accessible combustion chamber, which allowed OH*-chemiluminescence and OH-PLIF measurements for various fuel compositions. In particular, the hydrogen content in the synthetically mixed fuel gas was varied from 0% to 30%. The exhaust gas composition was additionally analyzed regarding CO, NOx, and unburned hydrocarbons. The results provide a comprehensive insight into the flame behavior during turbine operation. Efficient combustion and stable operation of the MGT was observed for all fuel compositions, while the hydrogen showed a strong influence. It is remarkable that with hydrogen contents higher than 9%, no OH radicals were detected within the inner recirculation zone, while they were increasingly entrained below hydrogen contents of 9%. Without hydrogen, the inner recirculation zone was completely filled with OH radicals and the highest concentrations were detected there. Therefore, the results indicate a different flame behavior with low and high hydrogen contents. Although the flame shape and position were affected, pollutant emissions remained consistently below 10 ppm based on 15% O2. Only in the case of 0% hydrogen, CO-emissions increased to 43 ppm, which are still meeting the emission limits. Thus, the combustor allows operation with syngases having hydrogen contents from 0% to 30%.

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References

Pilavachi, P. A. , 2000, “ Power Generation With Gas Turbine Systems and Combined Heat and Power,” Appl. Therm. Eng., 20(15–16), pp. 1421–1429. [CrossRef]
Carnö, J. , Cavani, A. , and Liinanki, L. , 1998, “ Micro Gas Turbine for Combined Heat and Power in Distributed Generation,” ASME Paper No. 98-GT-309.
Gupta, K. , Rehman, A. , and Sarviya, R. , 2010, “ Bio-Fuels for the Gas Turbine: A Review,” Renewable Sustainable Energy Rev., 14(9), pp. 2946–2955. [CrossRef]
Hasler, P. , Buehler, R. , and Nussbaumer, T. , 1998, “ Evaluation of Gas Cleaning Technologies for Biomass Gasification,” Tenth European Conference and Technology Exhibition, Biomass for Energy and Industry, Würzburg, Germany, June 8--11, pp. 272–275.
Zornek, T. , Monz, T. , and Aigner, M. , 2015, “ Performance Analysis of the Micro Gas Turbine Turbec t100 With a New Flox-Combustion System for Low Calorific Fuels,” Appl. Energy, 159, pp. 276–284. [CrossRef]
Wünning, J. , and Wünning, J. , 1997, “ Flameless Oxidation to Reduce Thermal No-Formation,” Prog. Energy Combust. Sci., 23(1), pp. 81–94. [CrossRef]
Cavaliere, A. , and Joannon, M. , 2004, “ Mild Combustion,” Prog. Energy Combust. Sci., 30(4), pp. 329–366. [CrossRef]
Arghode, V. , and Gupta, A. K. , 2010, “ Effect of Flow Field for Colorless Distributed Combustion (CDC) for Gas Turbine Combustion,” Appl. Energy, 87(5), pp. 1631–1640. [CrossRef]
Tsuji, H. , Gupta, A. , Hasegawa, T. , Katsuki, M. , Kishimoto, K. , and Morita, M. , 2003, High Temperature Air Combustion—From Energy Conservation to Pollution Reduction, CRC Press, Boca Raton, FL.
Lückerath, R. , Meier, W. , and Aigner, M. , 2008, “ Flox® Combustion at High Pressure With Different Fuel Compositions,” ASME J. Eng. Gas Turbines Power, 130(1), p. 011505. [CrossRef]
Schütz, H. , Lückerath, R. , Kretschmer, T. , Noll, B. , and Aigner, M. , 2006, “ Analysis of the Pollutant Formation in the Flox Combustion,” ASME Paper No. GT2006-91041.
Flamme, M. , 2004, “ New Combustion Systems for Gas Turbines (Ngt),” Appl. Therm. Eng., 24(11–12), pp. 1551–1559. [CrossRef]
Wünning, J. G. , 2005, “ Flameless Combustion and Its Applications,” Natural Gas Technologies, Vol. 30, Orlando, FL.
Zanger, J. , Monz, T. , and Aigner, M. , 2015, “ Experimental Investigation of the Combustion Characteristics of a Double-Staged Flox®-Based Combustor on an Atmospheric and a Micro Gas Turbine Test Rig,” ASME Paper No. GT2015-42313.
Herzler, J. , Herbst, J. , Kick, T. , Naumann, C. , Braun-Unkhoff, M. , and Riedel, U. , 2013, “ Alternative Fuels Based on Biomass: An Investigation of Combustion Properties of Product Gases,” ASME J. Eng. Gas Turbines Power, 135(3), p. 031401. [CrossRef]
Huang, Z. , Zhang, Y. , Zeng, K. , Liu, B. , Wang, Q. , and Jiang, D. , 2006, “ Measurements of Laminar Burning Velocities for Natural Gas-Hydrogen-Air Mixtures,” Combust. Flame, 146(1–2), pp. 302–311. [CrossRef]
Li, J. , Zhao, Z. , Kazakov, A. , Chaos, M. , Dryer, F. , and Scire, J. , 2007, “ A Comprehensive Kinetic Mechanism for Co, CH2O and CH3OH Combustion,” Int. J. Chem. Kinet., 39(3), pp. 109–136. [CrossRef]
Sadanandan, R. , Stöhr, M. , and Meier, W. , 2008, “ Simultaneous OH-PLIF and PIV Measurements in a Gas Turbine Model Combustor,” Appl. Phys. B, 90(3–4), pp. 609–618. [CrossRef]
Zanger, J. , 2016, “ Experimentelle Charakterisierung Eines Atmosphrisch Betriebenen, Jet-Stabilisierten Mikrogasturbinenbrenners Für Erdgas,” Ph.D. thesis, Universitt Stuttgart, Stuttgart, Germany.
Borghi, R. , 1985, “ On the Structure and Morphology of Turbulent Premixed Flames,”Recent Advances in the Aerospace Sciences, Springer, Boston, MA, pp. 117–138.
Federal Ministry for Environment, Nature Conservation and Nuclear Safety, 2002, “ First General Administrative Regulation Pertaining the Federal Immission Control Act (Technical Instructions on Air Qualitiy Control—ta luft),” Federal Ministry for Environment, Germany, epub, accessed Aug. 9, 2018, http://m.bmu.de/fileadmin/Daten_BMU/Download_PDF/Luft/taluft_engl.pdf

Figures

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Fig. 1

Schematic of the test rig [5]

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Fig. 2

Schematic of the combustion chamber [5]

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Fig. 3

Combustor prototype (picture: DLR/frank eppler)

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Fig. 4

Optical combustion chamber

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Fig. 5

Set-up for optical measurements

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Fig. 6

Instantaneous images of the measured OH distribution

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Fig. 7

Analyzed gradients of instantaneous OH-PLIF Images

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Fig. 8

Averaged images of OH*-chemiluminescence (left), OH-PLIF (center), and OH-PLIF gradients (right)

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Fig. 9

Ignition delay of fuel mixtures

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Fig. 10

Pollutant emissions based on 15% O2

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