Numerical study on the deposition characteristics of ash particles on the surface of heat exchanger tubes considering particle interactions

Abstract

In order to study the deposition of fly ash particles on the heat exchanger tube wall, a model was developed by combining the direct simulation Monte Carlo (DSMC) method with the random function method (RFM). The model incorporates the collision (including rebound and coagulation), deposition, and erosion processes of fly ash particles. Dynamic mesh technology was employed to accurately track the dynamic evolution of particle deposition morphology on heat exchanger tube surface. The model findings are consistent with the experimental data, and the obtained deposition morphology is also similar to that observed in the experiments. In addition, the effects of different incident velocities and mass flow rates on the deposition of fly ash particles are investigated, both in the presence and absence of collisions. This study found that under identical working conditions, the deposition mass on the tube is greater when particle collisions are considered than when they are not considered.