Performance Improvement of Biomass Cookstove: Insights from Computational Fluid Dynamics and Prototype Testing

Abstract

The biomass cookstove operation is a complex multiphysics process involving fluid dynamics, single and multiphase chemical reactions, heat and mass transfer, radiation, and more. The understanding of transport phenomena and improvement in equipment design can be achieved using the synergistic usage of prototype testing and computational fluid dynamics (CFD). The insights from our prior CFD studies and present prototype testing have helped to improve the secondary air flow pattern by orifice plate optimization, which led to the thermal efficiency of 41.6% from 38%. The analysis of flame height, flame temperature, and bed height shows that the burning rate is high in the middle section, due to rapid heating and ignition of particles due to conduction and radiation, with incomplete combustion of volatiles. The cross-sectional area in the middle zone was successfully modified to overcome this limitation. The thermal efficiency of the improved design is 50%. CFD simulations have been carried out for homogeneous combustion to understand the air flow pattern and temperature profiles in the different prototypes.