A simplified combustion model integrated with a particle growth dynamic model for top-lit updraft cookstoves

Abstract

Solid fuel stoves are used by over a third of the world's population for cooking and space heating. Efforts are being made to develop cookstoves with higher combustion and thermal efficiencies, but these efforts lack support of numerical models for predicting emissions that can be used in the design process. This work presents a simplified steady-state model to simulate combustion in a top-lit updraft (TLUD) cookstove integrated with a model for particle growth dynamics. The model incorporates the effects of cookstove operating parameters, specifically primary and secondary air fluxes and their temperatures and fuel composition (moisture, char, and volatile content) on various emissions and thermal characteristics of the cookstove, such as emission factors (EF), emission rates (ER), and size distribution of particulate matter. The results demonstrated that EF and ER do not necessarily follow the same trends, and therefore a lower EF might lead to a higher personal exposure. This raises serious concern over the high reliance on EFs as a metric to assess the performance of cookstoves. Emissions trends obtained from the model matched with the trends reported in previous studies. Sensitivity analyses demonstrated that a small variation in the cookstove operating parameters or fuel properties drastically changes emission.