A prediction model of fluid–solid erosion wear in hydraulic spool valve orifice

Abstract

Fluid–solid erosion wear may damage the port structure and change the linear characteristics of the spool valve. They may also affect null characteristics and the control accuracy of the valve, resulting in production and safety accidents. In the present study, the prediction model of the orifice throttling coefficient and worn profile for engineering applications such as compensation control and life degradation assessment is established. The collision probability between particles and the wall surface is particularly considered based on the E/CRC erosion wear model. The relationship between the spool opening and the impact angle of particles is investigated numerically when developing collision probability model. Meanwhile, the influence of particle concentration, spool opening, and differential pressure on the orifice throttling coefficient and worn profile is analyzed by experiments, and the microcosmic surface morphology of the spool metering edge is analyzed by scanning electron microscopy (SEM). The results show that the impacting of solid particles on the orifice will result in extrusion-thin platelets flaking wear and deformation wear. The maximum relative error between the predicted results and the experimental measurements is 2.25%. Moreover, the predicted results of the model are in good agreement with the measured values under different particle concentrations, spool openings and differential pressure.