A hybrid EDC/Flamelet approach for modelling biomass combustion of grate-firing furnace

Abstract

This paper proposes a new combustion model for the simulation of biomass combustion. It is developed based on the framework of the well-known Eddy Dissipation Concept (EDC) approach, which has the ability to incorporate chemical kinetics in turbulent reacting flows and thus makes it suitable for modelling gas-phase combustion. However, its high computational cost when using detailed chemistry has made it impractical for modelling large/industrial setups. To address this handicap, the proposed approach decouples the real-time calculation of chemical and mixing processes by importing a pre-calculated steady laminar flamelet library into EDC. The development of this new model is performed based on a modified version of EDC (called Extended EDC), which is capable of modelling the gas-phase of biomass combustion over a wide range of turbulent flow conditions. The proposed model is validated by simulating the well-documented experiment of the piloted jet flames of Barlow and Frank. The performance of the model is then evaluated by simulating a small-scale grate firing biomass furnace. The results show that, overall, the proposed model can be used to model biomass combustion at substantially low computational cost.

Keywords:

• biomass
• gas-phase combustion
• CFD
• EDC
• flamelet

Acknowledgements

The financial support of this research was provided Biovalco Inc. and the Natural Sciences and Engineering Research Council of Canada (NSERC). The First author (M. Farokhi) acknowledges the financial support received from the Faculty of Graduate Studies (GETS award).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Natural Sciences and Engineering Research Council of Canada: [Grant Number N/A].