Numerical simulation of high-voltage electric pulses crushing heterogeneous granite
A detailed understanding of the fragmentation mechanism by the high-voltage electrical pulses(HVEP)technolo-gy is essential to enhance ROP in rock-breaking and to optimize the electrical parameters.The particle flow code(PFC)software and Voronoi tessellation were used to generate granite models with non-uniform dielectric properties.The plasma channel growth process was simulated from the current field,the circuit field and the electric breakdown field,and also the influence of heterogeneity on the breakdown path was analyzed.The HVEP rock-breaking efficiency and the electric pulse rock-breaking effect of different granites were compared.The results show that the increase of heterogeneity of granite increa-ses the initial electric field's extreme value,and correspondingly reduces the energy demand of electric rock breaking.There is a preferential development region in the growth direction of the plasma channel,and the growth process of the plasma chan-nel shows that the electric field concentration at the tip of the channel is stronger than that at the trunk of the channel.The difference in the heterogeneity of the granites results in significant difference in the total length and the average penetration depth of the plasma channels.In the range of a certain degree of heterogeneity,the HVEP crushing effect is positively corre-lated with the degree of heterogeneity.The single-pulse electric rock breaking efficiency of different heterogeneity granites has little difference.The longer the total length of the plasma channel,the higher the electric rock breaking efficiency is.
electric pulses rock-breakingheterogeneous graniteelectric breakdownplasma channel drillingrate of pene-tration
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