The effect of magnetic field on the electric breakdown trajectory of high‐voltage electric pulse rock breaking

Abstract

AbstractHigh‐voltage electric pulse drilling technology has the advantages of high rock‐breaking efficiency, low energy consumption for rock breaking, and good quality of well wall, which is a new and efficient potential rock‐breaking method. In this paper, we constructed a numerical simulation model of rock electric breakdown and realized the whole process of rock breaking and plasma channel generation by high‐voltage electric pulse. The results of the study showed that the change of magnetic field has a large influence on the formation of plasma channels inside the rock, and under the self‐magnetic field environment, the plasma channels inside the rock show branching, and the maximum penetration depth and maximum damage depth are higher than those under the non‐magnetic field environment. In the external magnetic field environment, the plasma channels gradually tend to develop “downward” (inside the rock), and the temperature distribution of the plasma channels inside the rock is more concentrated. In the presence of a magnetic field, the speed and degree of freedom of charged particles are limited. In an external magnetic field environment, the charged particles cause fewer particles to deviate, and the particles show a “downward” accumulation phenomenon. The research in this paper can provide certain theoretical and technical guidance for the development of electric pulse rock‐breaking technology and provide reference for the development and parameter optimization of electric pulse rock‐breaking tools.