Inorganic compounds from molten and vaporised ash in biomass combustion can cause slagging, fouling and corrosion in the boiler. In this study, the behaviour of ash is modelled by combining CFD and thermodynamic equilibrium calculations. This was done by linking the CFD code Ansys Fluent and the thermodynamic phase equilibrium calculation code ChemApp. Two test cases were calculated: a BFB boiler of 107 MWth burning bark and the same boiler burning a mixture of bark and sludge. The model was used to predict vaporisation, melting, gas phase reactions and condensation of the ash in the boiler. In the test cases, the model predicted a risk of slagging as well as fouling and corrosion for bark, while during the co-combustion of bark and sludge the risks were predicted to be somewhat lower.
|Title of host publication||Proceedings of the Nordic Flame Days 2015|
|Publisher||International Flame Research Foundation IFRF|
|Publication status||Published - 2015|
|MoE publication type||B3 Non-refereed article in conference proceedings|
|Event||Nordic Flame Days 2015 - Copenhagen, Denmark|
Duration: 6 Oct 2015 → 7 Oct 2015
|Conference||Nordic Flame Days 2015|
|Period||6/10/15 → 7/10/15|
Nieminen, J., & Bajamundi, C. (2015). Modelling the behaviour of ash in a BFB boiler by combining CFD and thermodynamic equilibrium calculations. In Proceedings of the Nordic Flame Days 2015 International Flame Research Foundation IFRF.