A tube heat transfer prediction model considering static friction coefficient of dense particle flow

Abstract

Particulate material is an important heat transfer medium in industry. The heat transfer process of dense particle flow around tubes has important applications in industrial waste heat and solar energy conversion. However, rapid prediction of particle heat transfer processes is still worth investigating, especially when the particle flow is affected by the coefficient of friction. A heat transfer model of dense particle flow around a tube was established, the effects of particle size, density and static friction coefficient on the heat transfer characteristics were explored, and a heat transfer prediction equation considering the static friction coefficient was constructed originally. The results show that the particle size has the most significant effect on the heat transfer. As the particle size increases from 2 mm to 4 mm, the average effective heat transfer coefficient of the tube decreases from 262.35 W/(m2·K) to 217.31 W/(m2·K). The effect of particle density on the heat transfer is reflected in the difference in the heat capacity of the particles, and has little effect on the flow of the particles. The particle static friction coefficient mainly affects heat transfer by affecting the flow state of the particle flow. The average contact number decreases from 63.9 to 38.9. The relative error of the modified model is reduced from 8.9% to 3.78%.