Numerical study of flow and particle dynamics for fly ash separation in a biomass boiler

Abstract Efficient separation of fly ash is of great significance for ensuring the thermal efficiency and safe operation of biomass boilers. In this study, a 140 t/h biomass vibrating grate direct-firing boiler was selected as the research object, and a systematic numerical simulation was carried out to investigate the fly ash separation process inside the boiler. Different baffle geometries, arrangement patterns, and particle sizes were considered to explore their effects on particle separation efficiency and flow field characteristics. The results show that the arc-shaped double-row parallel baffle configuration exhibits the best performance in enhancing gas–solid separation, achieving a maximum particle capture efficiency of 20.03%. This study provides quantitative evidence and optimization guidance for the engineering design of fly ash separation structures in biomass boilers.