水中丝爆等离子体破岩机理研究

Rock breaking mechanism of underwater wire explosion plasma

摘要:

在隧道开挖、矿山开采等基础工程建设中，岩石爆破技术发挥着重要作用。等离子体碎岩技术具有无污染，破碎过程中无飞石、无有害气体的产生，使用方便，作业效率高，是替代炸药碎岩的最有效可行的方法。本文研究了水中丝爆产生等离子体破碎岩石的机理，分析了高电压脉冲放电过程中的铜丝融化过程，建立了铜丝在各阶段变化的电阻模型，利用MATLAB对不同阶段放电电路的电流进行了数值仿真分析，并与实验得到的电流波形进行对比。研究发现，电流波形，上升沿时间越短，脉冲放电效果越好。铜丝变化产生等离子体的过程中，等离子体通道具有一定的电阻性。实验数据结果与模型数值计算结果基本相符。

关键词:丝爆;高压脉冲放电;等离子体;破碎岩石;放电模型

Abstract:

Rock blasting technology plays an important role in the construction of infrastructural projects such as tunnel excavation and mining. The plasma rock breaking technology is characterized with no pollution, no flying stones or harmful gases in the blasting process, easy operation and high efficiency, and is the most effective and feasible method to replace the explosive. In this paper, the rock breaking mechanism of plasma generated by underwater wire explosion is studied. The process of copper wire melting during high-voltage pulse discharge is analyzed. The resistance model of copper wires changes at various stages is established. Numerical simulation analysis is performed of the current of the discharge circuit at different stages with MATLAB and compared with the experimental current waveform. The study finds that the shorter the rising edge time of the current waveform, the better the pulse discharge effect. During the process of generating a plasma by a copper wire, the plasma channel has certain electrical resistance. The experimental results are basically consistent with the model numerical calculation results.

Key words:wire explosion; high voltage pulse discharge; plasma; broken rock; discharge model