Ecological Aspects in Control of Small-scale Biomass Fired Boilers

Control of combustion in small-scale boilers has been standing outside interest for a long time. More attention has been paid to design of the boilers than to economic and ecological aspects of their operation. To the question under which operating conditions of the boiler a controller carries out its activities has been paid a limited attention. The quick by developing use of biomass fired boilers, local shortage of quality biomass, legal restriction on emissions and available cheaper instrumentation have caused a turn in replacing older simple control solutions by more sophisticated technology. The final goal is evident: to achieve for small-scale boilers to be able to operate automatically fulfilling ecological limits comparable with those usual in fullscale boilers, even when firing biomass of lower quality and no skilled service can be expected. Some experience obtained from experiments aimed at this goal and improvements carried out on pilot boilers are reported in this paper.