ABSTRACT
In this work, the effects of proposed measures for improving environmental footprint of woody and non-woody biomass combustion in residential appliances, comprising partial insulation of combustion chamber and inclusion of combustion intensifier are numerically and experimentally evaluated. In the numerical part, a simplified modeling approach for wood pellets, based on Finite-Rate and Eddy-Dissipation model, is presented and the obtained combustion reaction maps are extensively discussed. The accompanying experiments with wood and agropellets are performed in a multi-fuel boiler equipped with rotary pellet burner. It is found that significant reductions in pollutant emissions are obtained (CO – 31 to 78%, PM – 28 to 56 mg/Nm3 at standardized oxygen content). The results also show that by combining both measures, CO emissions below 1000 mg/Nm3 at the standardized oxygen content (limitation for Class 4 according to EN 303–5:2021), without a significant drop in combustion efficiency (approx. 2%), can be expected for agropellets. The optimal combustion conditions can be achieved with lower excess air ratio, whereby a slight reduction in NOx emissions can be accomplished.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Table