Sedimentary characteristics of particle motion in supercritical water in different channels

[Background] Motion characteristics of fine particles in different pipelines is of great significance to the development of two-phase flow and improves the removal efficiency of particulate matter emitted from power plants. [Purpose] This study aims at the effects of temperature gradient and velocity on the motion law and distribution characteristics of fine particulate matter in supercritical water. [Methods] Ansys CFX software was employed as simulation tool, and the κ-ε model was used to predict the turbulence change in the channel. Motion deposition characteristics of particles with different sizes (1 ∼ 10 μm) in different pipelines in the supercritical water were calculated and analyzed. [Results] Simulation results showed that the motion deposition concentration of fine particulate matter in different pipes was roughly shown as 'M' distribution at different inlet temperatures. At the same time, there was an extreme value of particulate matter concentration near the pipe. Under different inlet speed conditions, the distribution of particle concentration in each pipeline was very discrete at low speed, and the concentration of particulate matter in each pipeline exhibited their own distribution characteristics while the speed was increasing. [Conclusion] The kinetic deposition of particles is the result of the momentum exchange between the particles and the resistance of the particle movement. (authors)