The problems of biomass boilers include (1) combustion difficulties and low heat generation due to the high water content of the wood chips used as fuel, (2) deterioration in thermal efficiency due to exhaust heat during operation. In this study, a dryer resembling a solar chimney is installed outside the combustion chamber of a biomass boiler to generate natural convection using the heat energy emitted from the biomass boiler, with the aim of reducing the moisture content of the wood chips. This enabled the wood chips to be dried in a short time.
