Non-gray gas and particle radiation in a pulverized coal jet flame
KAUST DepartmentClean Combustion Research Center
Computational Reacting Flow Laboratory (CRFL)
Mechanical Engineering Program
Physical Science and Engineering (PSE) Division
Embargo End Date2024-10-22
Permanent link to this recordhttp://hdl.handle.net/10754/685118
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AbstractIn pulverized coal combustion, the participating radiative media includes gas, soot, and coal/char particles; a fundamental understanding of their radiation behavior is essential for the prediction of radiation heat transfer and control of radiation in the furnace. In this study, the individual contributions of gas, soot, and coal particles to the total radiation were examined based on the large eddy simulation of the CRIEPI pulverized coal jet flame. The radiation transfer equation was solved using the discrete ordinate method with state-of-the-art non-gray radiative property models of multi-phase media. The full spectrum correlated k-distributions (FSCK) model was used to calculate the radiative property of the gas-soot mixture. A burnout-based particle radiative property model was applied for coal/char particles. The results showed that the predicted spatial distributions of coal particles, tar, and soot were in good agreement with the experimental data. The gray gas radiation model predicted temperatures approximately 50 K lower in this flame, and the peak soot volume fraction was predicted at approximately 22% lower. For the laboratory scale burner under examination, the individual radiative contributions of gas, soot, and coal/char were found to be 35%, 40%, and 25%, respectively, so that it was necessary to consider all components for accurate prediction. Moreover, these contribution ratios varied with the flame position. Because of the high particle concentration, the individual contribution of coal/char particles accounted for up to 65% in the devolatilization region. Soot radiation played an important role in the pulverized coal flame. In the region where the ensemble-averaged soot volume fraction reached the maximum of 2.7 ppm, the individual contribution of soot was 50% of the total radiation, which accounted for 70% of the total particles (soot and char) radiation.
CitationGuo, J., Jiang, X., Im, H. G., & Liu, Z. (2022). Non-gray gas and particle radiation in a pulverized coal jet flame. Combustion and Flame, 246, 112433. https://doi.org/10.1016/j.combustflame.2022.112433
SponsorsThis study was financially supported by the National Natural Science Foundation of China (51906075), National Key Research and Development Program of China (2019YFE0100100), and the King Abdullah University of Science and Technology (KAUST). Simulations utilized the resources at the KAUST Supercomputing Laboratory. We also wish to thank Prof. Jun Hayashi at Kyoto University for providing experimental details.
JournalCombustion and Flame