煤岩受热及损伤过程的声发射特性研究

Study on acoustic emission characteristics of coal and rock during heating and damage

物质燃烧产生的声波特性可进行煤自燃监测预警,利用声发射仪和煤岩受载破坏系统对煤在接收频率为1 kHz和2 kHz时的声发射信号演化规律和能量分析,发现煤在受热升温的过程中会产生声信号,且随着接收频率的增大,频率高的声发射信号与温度的相关性更弱一些。对岩石在不同温度下的应力-应变特性进行分析,结果表明,随着温度的升高,岩样的峰值强度逐渐降低,且施加相同的应力发生的应变程度增大。煤岩升温过程中的声发射特性及变化规律,为利用声信号预警预报矿井火灾提供研究方向。

The acoustic characteristics generated by material combustion can be used for monitoring and warning of coal spontaneous combustion, the evolution law and energy analysis of acoustic emission signal of coal at the receiving frequencies of 1 kHz and 2 kHz are carried out by using acoustic emission instrument and coal rock loading damage system.The results show that the acoustic emission signal will be generated during the heating process of coal, and the correlation between the acoustic emission signal with higher frequency and temperature is weaker with the increase of the receiving frequency.The stress-strain characteristics of rocks at different temperatures are analyzed.The results show that with the increase of temperature, the peak strength of rock samples gradually decreases, and the strain degree caused by applying the same stress increases.The acoustic emission characteristics and change rules in the process of coal and rock heating provide the research direction for early warning and prediction of mine fire using acoustic signals.