The effect of solid particle size and concentrations on internal flow and external characteristics of the dense fine particles solid–liquid two-phase centrifugal pump under low flow condition

In the energy conversion device and fluid transport equipment, the solid–liquid two-phase centrifugal pump occupies a large proportion, but the transport mechanism of dense fine particles has not been studied in detail. In this work, the solid–liquid two-phase flow in a centrifugal pump was numerically simulated by the mixture model. Two-phase performance tests with different particle concentrations and particle sizes at a low flow rate (0.6Qd) were conducted, and dimensionless analysis on the effect of particle concentrations and particle sizes on head and efficiency was conducted. The results show that the increase in particle size and particle concentration can increase the influence coefficient of head and efficiency and the influence of the two parameters on efficiency is greater than that on the head on the whole. The increase in particle size and concentration will lead to more uneven distribution of the solid volume fraction in the pump. The transport of dense fine particles absorbs a large amount of energy, which leads to the relative decrease in the kinetic energy of the liquid phase and inhibits the generation of the vortex in the impeller passage.