Research on the erosion-abrasion of the sliding spool of Electro-Hydraulic Proportional Directional Valve

Electro-Hydraulic Proportional Directional Valve (EHPDV) is a key component in an electro-hydraulic proportional control system. Erosion-abrasion caused by solid particles within the oil is one of the major concerns in hydraulic control valves which may result in equipment malfunction and even failure. In this paper, the erosion-abrasion of a sliding spool of EHPDV was researched through Computational Fluid Dynamic (CFD) simulation and the analysis consists of three steps: the continuous phase flow field simulation, particle tracking, and erosion calculation. Therefore, a three dimensional model of the valve was built and the grid was meshed by use of ICEM. Then, a coupled Eulerian-Lagrangian approach was employed to solve the liquid-particle flow characteristics within the EHPDV, the Erosion/Corrosion Research Center (E/CRC) erosion model and the Grant empirical formula of particle-wall rebound models were utilized to predict the erosion rate. The simulation results indicated that the average erosion rate of the sliding spool would nonlinearly various with the valve opening. In addition, the maximum and average erosion rate of the sliding spool would gradually increase with the velocity. 10 µm is the critical diameter, and the erosion rate would decrease with the increases of the particle diameter if the particle diameter is above 10 µm and inversely when the diameter is below 10µm. Based on the simulation results, an erosion prediction model of sliding spool was further proposed, which provides a theoretical principle for forecasting the lifecycle of EHPDV.