Summary

On 23 November 2009, a workshop was held at EDF R&D in Chatou entitled “Combustion characterisation techniques for pulverised coal/ Needs for modelling and validation of coal combustion in PC boilers.”  The workshop was part of the EDF-IFRF Work-out program “Methodology for the characterization of pulverized coals: the need, the experimental conditions to obtain reliable data” – which started during 2009 and will continue during 2010, with both experimental and model validation activities.

The aim of this particular encounter between some 25 representatives from academia and industry across Europe was to define the information needed for comprehensive modelling of coal combustion and the techniques and methods to obtain such information.

IFRF and EDF research groups introduced the meeting and addressed the main objectives in two presentations: “Needs for modelling and validation of coal combustion in boilers" (IFRF) and “Code-Saturne®: The 3D modelisation of the coal combustion/oxy-combustion/co combustion in Boilers” (EDF).

In the following presentations the solid fuel properties to be considered as inputs in coal combustion comprehensive modeling were considered.  These include immediate and ultimate analysis, particle size distribution, density, shape factor, and ash composition.) Approaches and correlations to be used in sub-models were reviewed (devolatilisation and volatile composition, homogeneous combustion chemistry, char burnout sub-model, etc.)

On the experimental side, the IFRF team presented an overview on solid fuel characterisation methods and related modelling issues, and then the discussion was focussed on the most common methodology for getting high temperature, high heating rate information on coal combustion: Isothermal Plug Flow Reactors/Drop tubes.  For the latter, examples of methodologies, uncertainties evaluation, and brand new data were shown by IFRF and University of Haute Alsace researchers.  Particular attention was devoted to the assessment of experimental uncertainties, coupling experimental characterization of devices with CFD modeling of their performances as well.

Finally the status of the IFRF Solid fuel database was reported, including examples on kinetics assessment on devolatilisation and char oxidation by analysis of raw data produced by drop tube devices.

The presentations here are numbered in the order in which they were given.