CFD-DEM-based Numerical Simulation of Erosion Characteristic of Multistage Pressure Relief String Regulating Valve

The regulating valve applied in coal liquefaction systems becomes seriously worn and its service life decreases because of a significant difference in pressure and solid–liquid flow. This study proposes a wear-resistant multistage pressure relief string-regulating valve, and examines the characteristics of depressurization of flow and the erosion of its throttle element by using computational fluid dynamics (CFD) simulations and the discrete element method (DEM) combined with the E/CRC (Erosion/Corrosion Center) erosion model of the WC-Co coating. The influence of different sizes of the opening of the valve and varying differences in pressure on the characteristics of erosion is analyzed. Moreover, properties of collisions between particles (such as the particle impact velocity and mass per second) are used to represent and analyze the characteristics of erosion. The numerical results show that the cylinder, flat, and bevel of the valve are at high risk of erosion. The characteristics of erosion of the multistage pressure relief string-regulating valve studied in this paper can provide a reference for optimizing methods of erosion prevention.

Keywords:

Multistage depressurization , Regulating valve , String valve , CFD-DEM , Erosion characteristic , Solid–liquid flow