A fast thermal non-equilibrium eulerian-eulerian numerical simulation methodology of a pulverised fuel combustor

A thermal non-equilibrium Eulerian-Eulerian (EE) three-dimensional combustion and radiative heat transfer model is proposed for application in pulverised fuel combustors. It eliminates the need to explicitly track the fuel particles in a Lagrangian frame of reference, thereby significantly reducing the computation time required. The homogenised Eulerian solid-phase model employs a species-transport approach to track gas constituent distribution inside the computational domain and solves scalar fields for the pseudo particle mass, energy, and radiation interactions. Therefore, it effectively captures the heat transfer between the particle and continuous phases. The validity of the modelling approach is demonstrated via application to a 2.165 [MWth] lab-scale swirl pulverised-fuel burner operating at full load. The results of the proposed model are compared to both measured data and that of a detailed numerical model using the conventional Eulerian-Lagrangian (EL) frame of reference. The proposed model captures the combustor's total wall heat flux distribution with relative errors between 0.5% and 5%. The ability to capture the fluid flow and heat transfer phenomena at lower loads is also demonstrated. A relative computational cost reduction of approximately 50% is observed for different mesh refinements and load cases. Therefore, the proposed approach fulfils the need for a fast yet sufficiently accurate three-dimensional CFD modelling methodology that can be used for generating large databases of CFD simulation results for surrogate model development.