Assessment of wood pellet combustion in a domestic stove

Wood pellet is a densified fuel with homogeneous physical properties suitable for use at various scales in domestic and industrial furnaces. A wood pellet stove is a small-scale furnace for domestic heat production that can replace conventional oil or gas boilers. Since the fuel properties of wood pellet are very different from those of oil or gas, the design of a wood pellet stove requires profound understanding of solid fuel combustion as well as of gas flow mixing and reactions. Due to limitations on the height of an installed furnace (~1 m), poor design of the furnace, air supply, fume extraction, or the heat exchanger may lead to excessive CO emissions or low energy efficiency. This study evaluated the design of an existing wood pellet stove with 30,000 kcal/h capacity, using experimental and computational techniques in order to optimize the furnace design. The results show that it is critical to minimize unused furnace volume and to enhance gaseous mixing for reduced CO emissions while maintaining sufficiently high temperatures for fast oxidation.