MODELLING PULVERISED COAL COMBUSTION USING A DETAILED COAL COMBUSTION MODEL

ABSTRACT

The ability to assess the combustion behaviour of internationally traded coals and accurately predict flame characteristics, stable species concentration, unburned carbon and pollutant emissions is of importance to the power generating industry. Despite recent advances in coal combustion modelling detailed understanding is still lacking on the exact role of the coal maceral content on the combustion process. Here, a CFD-based coal combustion model that includes these effects has been developed to try to improve the predictive capability. A computational simulation of a 1 MW (thermal), pulverised fuel combustion test furnace, which was designed to replicate the time-temperature history of a full-scale furnace, was performed. This furnace also contained a triple-staged low-NO_x swirl burner. A number of simulations were made using a number of coals in order to calculate NO_x and the unburned carbon-in-ash, the latter being a sensitive test for the accuracy of the char combustion model.

Keywords:

• pulverised coal combustion
• low-NO_x burner
• CFD modeling
• char burnout model

The authors would like to acknowledge EPSRC, the ESR21 Network and E.ON UK plc (D. M. Turner, D. Miller, J. Fackrell and R. Irons) for their financial support and assistance.

Notes

∗Values are on a v/v basis.

∗∗Experimental values quoted here are interpolated from the measured (dry) data and corrected to a v/v basis.