Dr.-Ing. Jan Köser
Working area(s)
Contact
koeser@rsm.tu-...
work +49 6151 16-28898
fax +49 6151 16-28900
Work
L1|08 122
Otto-Berndt-Str. 3
64387
Darmstadt
A reliable supply of energy and electricity will require a combination of renewable, nuclear and fossil fuels such as coal, oil and natural gas in the future. Although the reduction of greenhouse gases is a top priority worldwide, conventional power plant technology generates high emissions through the combustion of fossil fuels in an air atmosphere. This central conflict can be solved through carbon capture and storage (CCS) technologies. Oxyfuel combustion is one of the most promising CCS technologies to capture CO2. Fuel is combusted with a mixture of oxygen and recirculated flue gas instead of air. This results in a CO2-rich flue gas and enables efficient CO2 separation. The exchange of the nitrogen contained in air by CO2 and H2O leads to completely different combustion processes. This can lead to instabilities and local dilutions of the flame. In order to obtain a clear understanding and a correct description of the combustion behavior for this particular atmosphere, physical and chemical models based on results from experimental investigations are required. This is the goal of the SFB / Transregio 129 Oxyflame (www.oxyflame.de), which is supported by the German Research Foundation (DFG) (www.dfg.de).
The aim is to characterize the influence of the combustion atmosphere, the temperature and the flow field on the ignition and combustion processes of fuel particles such as coal, biomass or synthetic coal. A specially developed flat flame burner is used for the investigation. A central jet serves to transport individual solid particles into the combustion area. The special feature is the fully pre-mixed flat flame, in the hot exhaust gas of which the particles burn. Since well-defined boundary conditions were the focus of the burner design, the carrier gas of the coal particles is also pre-mixed, resulting in a continuous flame front and thus a very well-defined heating start point. The gas composition can be varied and the temperature curves along the jet axis are known.
In the experiments, laser diagnostics and optical measurement techniques are mainly used. One focus is on the multi parameter investigation such as ignition timing, particle shape and size. These measurements serve as a basis for experiments with higher particle loading and turbulent flow fields.
- Köser, J., Becker, L., Vorobiev, N., Schiemann, M., Scherer, V., Böhm, B. and Dreizler, A.Characterization of single coal particle combustion within oxygen-enriched environments using high-speed OH-PLIF, Applied Physics B, 121 (4): 459-464, 2015.
- Knappstein, R., Künne, G., Ketelheun, A., Köser, J., Becker, L. G., Heuer, S., Schiemann, M., Scherer, V., Dreizler, A., Sadiki, A. and Janicka, J.Devolatilization and volatiles reaction of individual coal particles in the context of FGM tabulated chemistry, Combustion and Flame, 169: 72-84, 2016.
- Köser, J., Becker, L. G., Goßmann, A.-K., Böhm, B. and Dreizler, A.Investigation of ignition and volatile combustion of single coal particles within oxygen-enriched atmospheres using high-speed OH-PLIF, Proceedings of the Combustion Institute, 2016.
- Köser, J., Knappstein, R., Goßmann, A.-K., Becker, L. G., Böhm, B., Janicka, J. and Dreizler, A.An experimental and numerical study of volatile combustion of single coal particles in an oxygen enriched atmosphere, 32nd International Pittsburgh Coal Conference, Pittsburgh, Pennsylvania, 2015.
- Knappstein, R., Ketelheun, A., Künne, G., Köser, J., Dreizler, A., Sadiki, A. and Janicka, J.A consistent approach for coupling the devolatilization of coal particles with tabulated chemistry, 15th International Conference on Numerical Combustion, Avignon, Frankreich, 2015.
- Weinkauff, J., Köser, J., Michaelis, D., Peterson, B., Dreizler, A., & Böhm, B. (2014, July). Volumetric flame measurements in a lifted turbulent jet flame using tomographic reconstruction of chemiluminescence, 17th Int. Symp. on Applications of Laser Techniques to Fluid Mechanics, 2014