Austria takes a worldwide leading position in the research and dissemination of biomass
boilers for heating in buildings, industrial and commercial plants both for local and district
heating systems. In the field of small scale boilers, mainly wood pellet boilers are used with
fuels with homogeneous and standardised combustion characteristics. In the field of middle
and large scale boilers, mainly woodchip boilers are used.
In plant operation, a larger boiler performance leads to higher requirements of the
combustion control because of the variety of fuels that can be used. In the segment of small
scale boilers, lambda probes (zirconium oxide probes) are state-of-the-art. At medium and
large scale plants, pure lambda probe control cannot guaranty low emission combustion,
because of the inhomogeneity of the fuels.
Fine particle emissions from biomass combustion often cause criticism on the technology in
different media reports. In large scale plants, bag- and electrostatic filters in combination with
cyclone separators are state-of-the-art. Especially in the small and medium segment,
convenient and cost- efficient solutions for the particle separation cannot be seen.
The aim of the present research project is to optimise the development of high efficient
biomass boilers with reduced emissions and a wide range of fuel flexibility. In the first step,
the combustion process should be optimised by a newly developed combustion control in
connection to an innovative CO-λ and NOx probes. The second step in this project is the
investigation of possibilities to integrate electrostatic fine- particle separators into a biomass
boiler. For an optimal integrated solution, research on the optimisation of the combustion
process is essential. Therefore, a model predictive control is developed which comprises a
fault-detection for the utilized sensors. The boiler performance, which is addressed, is
between 50kW and 1.0MW. The aims of the project should be reached in close cooperation
between a research company, a University and a biomass boiler producer.
The methodology of this industrial research is based on basic investigations in the area of
combustion control probes on test stands (lambda probe test stand) and at a real plant
during operation. An innovative model predictive control is developed and tested by the
implementation in a LabVIEW program with a gateway to the boiler combustion control. In
the area of fine particle separation, basic investigations both CFD modelling and
experimental should be carried out to analyse the integration of PM- separators to the boiler
in future.