Laser diagnostics of pulverized coal combustion in O2/N2 and O2/CO2 conditions: velocity and scalar field measurements
Abstract
Optical diagnostic techniques are applied to a 21 kW laboratory-scale pulverized coal–methane burner to map the reaction zone during combustion, in mixtures with varying fractions of O2, N2 and CO2. Simultaneous Mie scatter and OH planar laser-induced fluorescence (PLIF) measurements have been carried out to study the effect of the oxidizer/diluent concentrations as well as the coal-loading rate. The spatial distribution of soot is captured using laser-induced incandescence (LII). Additionally, velocity profiles at selected axial locations are measured using the pairwise two-dimensional laser Doppler velocimetry technique. The OH PLIF images capture the reaction zones of pilot methane–air flames and the variation of the coal flame structure under various O2/CO2 compositions. Coal particles devolatilize immediately upon crossing the flame interface, so that the Mie scatter signal almost vanishes. Increasing coal-loading rates leads to higher reaction rates and shorter flames. LII measurements show that soot is formed primarily in the wake of remaining coal particles in the product regions. Finally, differences in the mean and RMS velocity field are explained by the combined action of thermal expansion and the changes in particle diameter between reacting and non-reacting flows.Citation
Balusamy, S., Kamal, M.M., Lowe, S.M., Tian, B., Gao, Y. and Hochgreb, S., (2015). 'Laser diagnostics of pulverized coal combustion in O 2/N 2 and O 2/CO 2 conditions: velocity and scalar field measurements'. Experiments in Fluids, 56(5), pp. 1-16.Publisher
Springer Science and Business Media LLCJournal
Experiments in FluidsDOI
10.1007/s00348-015-1965-zAdditional Links
https://www.repository.cam.ac.uk/handle/1810/248377https://link.springer.com/article/10.1007/s00348-015-1965-z#article-info
Type
ArticleLanguage
enISSN
0723-4864EISSN
1432-1114ae974a485f413a2113503eed53cd6c53
10.1007/s00348-015-1965-z
Scopus Count
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