The results of the numerical simulations performed in a pulverised fuel boiler co-firing coal and Solid Recovered Fuels (SRFs) are presented. SRFs are initially modelled as a mixture of two different fractions (biogenic and plastic) and further simplifications are proposed to save computational expenses. The SRF submodels are validated with available data obtained from a laboratory-scale combustion facility. The furnace of a 600 MWe brown coal plant is further simulated. The respective boundary conditions are obtained from a performed large-scale measurement campaign during an SRF co-firing demonstration in the specific boiler. The results of the baseline case are in good agreement with the available experimental data for the large-scale boiler. A number of fuel and process-related combustion parameters is further examined, including the co-firing thermal share, injection locations and the Particle Size Distribution (PSD) of SRF particles. Computational Fluid Dynamics (CFD) modelling in large-scale boilers can be a reliable and efficient tool towards predicting specific changes of the combustion behaviour. It is particularly valuable when the intended investigations cannot be easily realised on a large scale, such as increasing the co-firing thermal share or modifying the injection locations of alternative fuels.

Keywords: solid recovered fuels, SRFs, co-firing, model validation, computational fluid dynamics, CFD, large-scale boiler simulations