Particle-scale simulation of heat transfer in liquid-fluidised beds

In this work, the details of a thermal Combined Continuum and Discrete Model for simulating the heat transfer behaviour of liquid–particle flow systems have been presented. Simulations of a liquid-fluidised bed with heated walls have been carried out to examine the particle-scale flow and heat transfer behaviour. The simulation results from two convective heat transfer models (Agarwal, 1988, Chemical Engineering Science, 43, 2501 and Li and Mason, 2000, Powder Technology, 112, 273) were critically evaluated using the experiments by Patel and Simpson (1977, Chemical Engineering Science, 32, 67). The prediction of a maximum in the heat transfer coefficient for a bed voidage around 0.75 using Li and Masonʹs convective heat transfer model, is in good agreement with the experimental findings of Patel and Simpson. It also found that there is a maximum in the normalised mean particle speed at a bed voidage just above 0.7, corresponding to the maximum in the heat transfer coefficient. Investigation of the particle motion and mixing behaviour in the simulated systems indicated that they are decoupled from the bed thermal behaviour under the range of temperatures studied.