Study on CO emissions and performance analysis of a pellet stove

The conversion of chemical energy from biomass fuels into thermal energy, involves emissions in form of gaseous and particulate matter which can seriously affect human health and the environment. Combustion of wood pellets in small scale heating appliances is efficient and produces significantly lower emissions than the wood log combustion appliances. Carbon monoxide (CO) emissions from residential pellet heating devices mainly report during stationary operation, however, a considerable part of un-burnt fuels are emitted during the startup and stop (burnout) phases. Emission characteristics at each phase of the pellet stove operation are therefore important to be able to reduce CO emissions from residential pellet combustion. The aim of this study was to investigate CO emissions at three combustion phases being the startup, combustion (stationary operation) and burnout from a bottom feed pellet stove operated with nominal load (5 kW) and part load (2.5 kW) heat output. A performance analysis in terms of combustion efficiency together with different losses is also performed. The combustion experiments were conducted in a laboratory of Stuv manufacturing plant in Namur, Belgium.