Evaluation of oxy-coal combustion modelling at semi-industrial scale

During the oxy-fuel combustion process pulverized coal is burnt in an atmosphere consisting of pure O-2 mixed with recycled flue gas whereas during the conventional process air serves as the only oxidant. This entails specific conditions regarding thermo-physical properties which impact both combustion characteristics and heat transfer. Accordingly, adjustments within CFD codes are required in order to maintain accuracy and prediction quality criteria within simulations of oxy-coal combustion. The CFD code AIOLOS was used to evaluate recent oxy-coal specific implementations concerning the global chemistry mechanism and the heat transfer. For validation purposes extensive tests have been carried out at IFK's semi-industrial scale furnace (500kW(th)). Simulations have been performed for both, conventional air-firing and oxy-coal combustion conditions with US bituminous coal, and a comparison of simulation results and corresponding experimental data is given. In general, satisfactory agreement is observed. (C) 2012 The Authors. Published by Elsevier Ltd. Selection and/or peer-review under responsibility of SINTEF Energi AS