Promoting decentralised biomass combustion
Biomass is found abundantly in agriculture, yet biomass power plants are still very limited in use. Due to its variability in quality and seasonal availability, this fuel source may lead to serious problems in commercially operated biomass combustion systems. Thereby, alkalis and chlorine mixtures contained in biomass may generate slagging and fouling phenomena, to which corrosion is also related. Addressing these issues, dynamic boiler modelling for decentralised biomass combustion has been developed. Unlike the currently available steady state models, this on-line model may accurately follow heat transfers under continuous change of loads, running conditions and fuel properties. Most importantly, this tool may provide complete information of the current condition of the boiler and steam cycle offering both operational and additional on-line and off-line measurements. The model has been designed to monitor the heat transfer of a biomass fired fluidised boiler and has been successfully applied in a pulverised fuel boiler. Based on a modifiable Fortran programme, this tool is also applicable for a large variety of boilers. Providing real time data, the model may follow the heat transfer degradation and easily detect and analyse slagging and fouling deposits due to its modular structure. Even under limitations related to the plant operation modes, the tool may accurately predict further trends and enable operators to take actions for the safe and economic operation of the plant. Therefore, the thermodynamic model may optimise boiler efficiency, reduce operational costs and promote decentralised biomass combustion. The latter will eventually lead to greater reductions of greenhouse gas emissions and conservation of fossil fuels.
