Spatial distribution of emissions, temperatures, and particulate matter in a combustion zone of a pellet boiler
Alexander Backa, Radovan Nosek, Nikola Čajová Kantová, Sławomir Sładek
Abstract
Particulate matter (PM) and gaseous emissions from combustion pose a significant threat to air quality and human health. This study investigates the spatial distribution of PM and gaseous emissions within the combustion chamber of a small-scale pellet boiler. Real-time O 2 , CO 2 , CO, NO x , PM, and temperature measurements were conducted. Wood pellet combustion experiments were performed on an automatic bottom-feed boiler. Measurements were taken at various points within a 16×16×16 cm volume above the retort using a separate extraction system. Average CO, CO 2 , and temperature decreased with distance from the burner, while O 2 levels increased. The maximum temperature (900 °C) and PM concentration (133.7 mg/m 3 ) were recorded closest to the burning pellet layer, with 19% of the total vertical temperature drop occurring just above it, followed by a peak gradient (31%) between the next two layers. Elevated PM levels were also detected in cooler regions outside the flame. Total NO x concentrations were generally consistent. The highest CO concentration (10062.6 mg/m 3 ) coincided with the highest O 2 content (19.23%) outside the main flame. To analyze correlations between emissions and local temperatures, linear and polynomial regression models were developed. Correlations were identified between local oxygen availability, temperature, and emission concentrations.