Effects of air excess control in a heat storage solid fuel-fired household furnace

Due to a significant increase in electricity prices during the last decade and insufficient production capacity of the electric power industry in Serbia, many households that are currently using electric heat storage furnaces for heating have been forced to find an alternative solution for heating. A possible solution is replacing electric heating appliances with similar solid fuel-fired ones. Existing solid fuel-fired furnaces are often unsatisfactory with respect to their efficiencies and flue gas emissions. A prototype of a new concept of heat storage, solid fuel-fired furnace has been developed to meet these growing needs, providing electricity saving together with considerable environmental benefits. In order to examine furnace performance, efficiency and environmental aspects, and to assess the influence of air excess control in the furnace on the efficiency and flue gas emissions, numerous experimental tests were conducted. The amount of combustion air, the flue gas flow rate and the fuel feeding regime have been adjusted in order to keep the flue gas oxygen content in a relatively narrow range, thus obtaining controlled combustion conditions and, correspondingly, lower carbon monoxide emission and higher furnace efficiency. In this way, the furnace was made able to respond to the changes in heating needs, fuel quality and other parameters, which is considered to be advantageous in comparison with similar solid-fuel fired furnaces.