Investigation on the influence of particle physical parameters and blade tip clearance on the wear characteristic of submersible sewage pump

The submersible sewage pump is designed for conveying solid-liquid two-phase media containing sewage, waste, solid particles, and fiber components with its small and compact design, excellent anti-winding and anti-clogging capabilities. In this paper, the CFD-DEM coupling model is used to study the influence of different conveying conditions and particle parameters on the wear of the flow components of the submersible sewage pump operating with solid-liquid phases. At the same time, the energy balance equation is used to explore the influence mechanism of different tip clearance sizes on the internal flow pattern, wear and energy conversion mechanism of the pump. The study demonstrates that increasing particle volume concentration decreases the inlet particle velocity, intensifies wear in critical areas, and significantly reduces the pump's operational lifespan. Moreover, enlarging the tip clearance thickness enhances leakage vortex formation at the inlet, exacerbates particle aggregation, and escalates wear rates on the blade and volute. Concurrently, total energy loss and turbulent kinetic energy generation rise progressively, with a notable increase in the local loss coefficient of turbulent kinetic energy generation in the impeller channel midsection. Turbulence intensity near the volute tongue area within the impeller channel is correspondingly heightened. The findings of this study offer essential knowledge for performance enhancement and ensuring stable operation of submersible sewage pumps under solid-liquid two-phase flow conditions.