Towards fluidization in domestic heat systems: a cfd analysis of a fluidized bed cookstove

Conventional direct combustion and gasifier stoves operate a packed bed combustion technology, which is not favorable for combustion of fine solid biomass such as charcoal fines because of the compact nature of these fuels, which blocks airflow, leading to incomplete combustion. Conversely, fluidized bed combustion technology would effectively combust fine fuels; however, this is largely a monopoly of the industrial sector for processes such as heating, drying, separation, power generation, among others, and has never been adopted in cookstove designs despite its high-quality combustion and heat transfer potential. This study, therefore, presents the design, modeling, and simulation of a fluidized bed cookstove specifically developed for the direct combustion of charcoal dust, without the need for briquetting. The cookstove employed a bubbling fluidized bed combustion mechanism to enhance fuel–air mixing, hence promoting complete combustion and improving heat transfer. The stove design was a result of mathematical modeling using empirical formulae from previous studies. Computational Fluid Dynamics (CFD) was employed to model and simulate both the hydrodynamic behaviour and combustion processes within the reactor, thereby predicting the model performance. The cookstove featured a funnel-shaped combustion chamber with a dense phase region (Ø0.106 m × 0.119 m), a lean phase region (Ø0.212 m × 0.064 m), and a total reactor height of 0.182 m. CFD results indicated dense phase particle concentration with no entrainment and a maximum combustion temperature of 726.8℃.