Analysis of the Effect of Pressure on the Flow Characteristics of Pulverized Coal in a Pipe Based on Surface Energy Theory

The surface energy of coal powder has a significant impact on its tribological properties. Due to the presence of surface energy, free molecules in the air will undergo physical adsorption on the surface of coal powder, resulting in changes in surface structure. Pressure has a significant impact on the physical adsorption and surface structure of coal powder, thereby altering its flow characteristics. Establish a model for pneumatic conveying in the pipeline between the outlet of the coal mill and the boiler burner, and use CFD software Fluent to numerically simulate the movement of coal powder in the pipeline. In numerical simulation, the effects of different pressure levels on the velocity of coal powder at the outlet of the pipeline were studied under the same inlet and outlet pressure difference. The simulation results showed that within the pressure level range of this study, the velocity of coal powder at the outlet of the pipeline increased as the pressure decreased. Based on the analysis of surface energy theory, it can be concluded that as the pressure level decreases, the surface energy of coal powder decreases, the adsorption capacity of coal powder decreases, the interaction force between coal powder decreases, the friction loss of coal powder in the pipeline decreases, and the flow characteristics of coal powder enhance.