Oxygen Sensor for Control of Wood Combustion: A Review

Abstract

Zirconia type oxygen sensors, installed in the exhaust manifold of combustion engines, generate a voltage that drastically changes when the carburetor's air/fuel ratio deviates from the stoichiometric optimum. On this basis such sensors automatically regulate the supply of air and fuel in modern automobiles and in large wood-burning boilers. The literature is reviewed for use of the sensors in residential wood-burning furnaces and stoves, whose fires generally receive either too little or too much air. Unfortunately the sensors' temperature should be above 300 C, a temperature that fire effluents of the residential heating implements reach only near the end of the combustion zone, and then rapidly cool off on their further path to the chimney. Therefore, the sensors are far from ideal for residential heating implements, least of all for small stoves operated batchwise. They are more promising for the combustion control of continuously fueled pellet furnaces