Basic boiler cumulative distributions (fly ash, circulating material, bottom ash) — oxy-fuel and classical combustion conditions

•Using the population balance technique we model mass fluxes of granular materials in CFB installations within oxy-fuel and classical combustion conditions.•In order to demonstrate the model reliability, we compare our results with the pilot-scale CFB installation operating under oxy-fuel combustion.•Under the oxy-fuel combustion increases significantly the mass flux of circulating particles in relation to the mass flux of circulating particles observed under classical combustion conditions.•The simulation results also allow us to collect knowledge about the behaviour of a whole range of processes and phenomena occurring in the boiler.

In this study, we consider the complex problem of how to model steady regimes in CFB boilers, taking into account classical and oxy-fuel combustion. In accordance with the population balance technique and the theory for difference equations, we propose a novel mathematical description which is coherent and includes a set of original expressions and parameters describing behaviour of the CFB boiler as a complex system. We then discuss and illustrate how our internal-partial models and the governing model operate under oxy-fuel and classical combustion conditions. In global scale we compared simulation results with experimental data for operating the pilot scale 0.1 MWth test rig within the oxy-fuel combustion. The presented computational results can be used to realistically model mass fluxes in steady regimes in CFB industrial installations.

Graphical abstractIn this study, we consider the complex problem of how to model steady regimes in CFB boilers, taking into account classical and oxy-fuel combustion conditions.Figure: Basic boiler cumulative distributions (fly ash, circulating material, bottom ash) — oxy-fuel and classical combustion conditions.Figure optionsDownload full-size imageDownload as PowerPoint slide