Abstract:

To address the gas-solid erosion problem in waste heat boiler heat exchange tubes, this paper proposes a novel inlet structure consisting of a bell-mouth and a long divergent section. Using a Discrete Phase Model (DPM) validated by experimental data, the coupled flow field and erosion behaviors of conventional and novel tubes were compared. The effects of gas velocity, particle mass flux, and particle size on wall wear were systematically investigated. The results indicate that the new structure significantly improves the flow field and inhibits wear. Under varying gas velocities, the peak erosion rate of the novel tube is reduced by 58.8%–66.1%. As the particle mass flux increases, the erosion growth rate of the novel tube slows significantly, achieving a maximum reduction of 72.7%. Furthermore, as the particle size increases, the novel tube consistently lowers the peak wear by 57.1%–70.9%. This study demonstrates that the novel tube effectively optimizes the flow field and significantly weakens the erosion damage caused by gas-solid two-phase flow.

Key words: heat exchange tube, structure optimization, gas-solid two-phase flow, numerical simulation, DPM, erosion wear