화학공학소재연구정보센터
Combustion and Flame, Vol.218, 150-167, 2020
Flamelet tabulation methods for SOx formation in pulverized solid fuel combustion
In this paper, four different flamelet tabulation methods are evaluated for predicting SOx formation, including SO, SO2 and SO3, in pulverized coal flames with fuel-bound sulfur. The flamelet tabulation methods are evaluated in laminar counterflow flames under different operating conditions, and compared to the detailed chemistry solutions used for reference. The SOx species mass fractions are obtained by either extracting them directly from the flamelet library or solving the corresponding transport equations using source terms from the flamelet library. The results show that different from the other major species, O-2 is sensitive to the local combustion mode, and large discrepancies are obtained if the local combustion mode is incorrectly represented. The predicted O-2 has a direct effect on H2S oxidation. It is found that SOx species mass fractions can be accurately predicted by all flamelet tabulation methods in most regions of the computational domain, although there are non-negligible discrepancies in relevant regions where the premixed combustion mode is dominant. The differences between the flamelet predictions and the detailed chemistry solutions are quantified by introducing a newly defined parameter, which is formulated based on the difference between the flamelet predictions and the detailed chemistry solutions. The suitability of the flamelet model in predicting the SOx formation in pulverized coal flames with fuel-bound sulfur is justified through a chemical timescale analysis. The chemical timescale analysis is consistent with the findings for the flamelet predictions. (C) 2020 The Combustion Institute. Published by Elsevier Inc. All rights reserved.