基于空气环境下的高压击穿电热致裂煤体实验研究

利用搭建的高压击穿电热致裂煤体试验系统,以贵州林华煤矿的无烟煤为研究对象,研究了在空气环境下高压击穿电热致裂煤体的可行性,并对高压击穿电热致裂煤体的宏观和微观特征进行了研究。实验结果表明,在针-针电极下,空气介质的击穿场强为18.0~18.3 k V/cm,煤体的击穿场强为0.3~0.8 k V/cm,无烟煤的击穿场强小于空气的击穿场强。在相同条件下,各个煤样的击穿电压和破坏特征均不相同,击穿电压在20~41 k V,煤样主要有3种破坏类型。高压击穿电热致裂煤体过程中,等离子体通道位置的煤样呈现出烧灼状态,形成了大量裂隙和孔隙。同时,等离子通道周围煤体在高温条件下发生氧化反应,形成了新的氧化产物。

Experimental study on crushing coal by electric and heat in the process of high-voltage breakdown in the air condition

In order to study the feasibility of crushing coal by electric and heat in the process of high-voltage breakdown in air environment,as well as the macroscopic and microscopic characteristics of coal,an high-voltage breakdown testing system of coal is built,and the anthracite coal of Linhua coal mine in Guizhou province was selected for the test.Under the needle electrode-needle electrode,the experimental results show that the air dielectric breakdown field strength from 18.0 to 18.3 kV/cm,the breakdown field strength of coal body is 0.3-0.8 kV/cm,the breakdown voltage of anthracite coal is less than the breakdown voltage of air.Under the same conditions,the breakdown voltage and damage characteristics of coal samples are not the same,the breakdown voltage ranges between 20 kV and 41 kV,and there are three main types of damage on coal samples.In the process of the crushing coal by high-voltage,the coal samples of plasma channel presents a burning state,formed a large number of cracks and pores.At the same time,the oxidation reaction happened in the coal around the plasma channel under the condition of high temperature,formed new oxidation products.