Numerical-Experimental Study on the Erosion-Cavitation Wear of Coal Oil Slurry Valve

The coal oil slurry valves are located between the high pressure and intermediate pressure separators in the direct coal liquefaction unit. Because of the high pressure drop between the valve inlet and outlet, the cavitation occurs immediately once the coal oil slurry enters into the valve. Simultaneously, the severe erosion wear are also found on the valve components. Therefore, the erosion-cavitation wear has become a serious problem in the running of valve. In this paper, a numerical-experimental investigation on the erosion-cavitation wear of coal oil slurry valve is conducted. The cavitation experiments are used to verify the numerical modeling and calculation. Moreover, the expressions of functions used in the particle erosion model are defined from the erosion experiments in the high temperature environment. In the numerical simulation, the areas with the high risk of erosion-cavitation wear are predicted. The results showed that the most serious erosion-cavitation wear occurs on the top of valve spool. The particle erosion can also be found around the spool head. The numerical prediction of erosion-cavitation wear can be verified by the comparison between numerical results and actual failure morphology.