Grid-independent Eulerian-Lagrangian approaches for simulations of solid fuel particle combustion
Journal article, 2020

In this study, a computational fluid dynamics (CFD) model with three coarse graining algorithms is developed with the implementation of a layer based thermally thick particle model. Three additional coupling methods, cube averaging method (CAM), two-grid method (TGM) and diffusion-based method (DBM), are implemented. These coupling methods are validated and compared with the widely used particle centroid method (PCM) for combustion of a biomass particle in a single particle combustor. It is shown that the PCM has a strong dependence on the grid size, whereas the CAM and TGM are not only grid independent but also improve the predictability of the simulations. Meanwhile, a new parameter, the coupling length, is introduced. This parameter affects the sampling of the gas phase properties required for the particle model and the distribution of the solid phase properties. A method to estimate the coupling length by using empirical correlations is given. In general, it is found that a too small coupling length underestimates the heating-up rate and devolatilization rate, while a too large coupling length overestimates the O2 concentration at the particle surface. The coupling length also has an influence on the distribution of the gas phase products.

combustion

CFD

CFDSolid fuelEulerian-Lagrangian couplingCombustion

solid fuel conversion

Author

Jingyuan Zhang

Norwegian University of Science and Technology (NTNU)

Tian Li

Norwegian University of Science and Technology (NTNU)

Henrik Ström

Chalmers, Mechanics and Maritime Sciences, Fluid Dynamics

Norwegian University of Science and Technology (NTNU)

Terese Lövås

Norwegian University of Science and Technology (NTNU)

Chemical Engineering Journal

0300-9467 (ISSN)

Vol. 387 123964

Driving Forces

Sustainable development

Subject Categories

Energy Engineering

Chemical Engineering

Fluid Mechanics and Acoustics

Areas of Advance

Energy

Roots

Basic sciences

DOI

10.1016/j.cej.2019.123964

More information

Latest update

3/10/2020