Numerical simulation of ash deposition behavior with a novel erosion model using dynamic mesh

In this paper, a piecewise sticking model that considers both particle viscosity and energy conservation upon collision was presented to predict the development of deposition on a temperature-controlled probe. Furthermore, a novel erosion model which takes into account both the energy consumed during particle impact and the melt fraction of the deposition surface was introduced to improve the accuracy of the simulation. The erosion model in this work is applicable in all stages of deposition growth of common coal ash. The influence of the furnace temperature was also investigated by setting up three cases (1473 K, 1523 K, and 1573 K). The predicted characteristics were compared with experimental data in a 300 kW furnace. The results show that the mass of impact decreases while the deposition efficiency increases with the increase of deposition time. Compared with the simulation without erosion, the relative deviation reduces from 41.61% to 12.88% for thickness and from 3.39% to 2.35% for surface temperature with the erosion model. Additionally, Higher furnace temperatures lead to higher deposition efficiency and higher surface temperature. However, high temperatures may also be a factor impeding the deposit particles to accumulate.