Evaluation of devolatilization models in CFD for high-pressure entrained flow coal gasifier

고압 석탄 분류층 가스화기 전산유동에서 탈휘발 모델의 영향 평가

In an entrained flow coal gasifier, predicting the reaction behavior of pulverized coal particles requires detailed information on devolatilization, char gasification, gaseous reactions, turbulence and heat transfer. Among the input parameters, the rate of devolatilization and the composition of volatile species are difficult to determine by experiments due to a high pressure (~40 bar) and temperature (${\sim}1500^{\circ}C$). This study investigates the effect of devolatilization models on the reaction and heat transfer characteristics of a 300 MWe Shell coal gasifier. A simplified devolatilization model and advanced model based on Flashchain were evaluated, which had different volatiles composition and devolatilization rates. It was found that the tested models produce similar flow and reaction trends, but the simplified model slightly over-predict the temperature and wall heat flux near the coal inlets.