Modeling and Coupling Particle Scale Heat Transfer with DEM through Heat Transfer Mechanisms

The detailed heat transfer mechanisms particle interior, gas film around particles, gas gap between contact surfaces, and rough surface are considered to model heat transfer between particles. The validation of the heat transfer model is accomplished and the predicted results show good agreement with other experiments. From the quantitative comparison of four heat transfer paths, it is revealed that the heat transfer through gas gap and rough surface could be neglected for a particle diameter larger than 2 mm. Furthermore, the detailed heat transfer model is coupled with the discrete element method (DEM) to calculate macro effective thermal conductivity (ETC) of fixed beds, and the accuracy and applicability is verified by comparing with other estimated and experimental results. The influence of particle diameter, density, specific thermal capacity, and thermal conductivity on ETC is investigated. Results show that the proposed heat transfer model provides an effective and accurate way to couple with DEM in the particle system.