Study on the precursor characteristics of coal energy spontaneous combustion process using infrasound wave monitoring and warning

Abstract

The spontaneous combustion of coal energy has seriously threatened energy security, and there is an urgent need for monitoring and warning of coal energy. Therefore, this article innovatively proposes a method of using infrasound waves to monitor coal energy spontaneous combustion, establishes a coal spontaneous combustion(CSC) infrasound wave experimental testing system, and studies the precursor characteristics of coal energy spontaneous combustion process. The results indicate that there is a good positive correlation between the amplitude of the dominant frequency of the infrasound wave generated by CSC and temperature, with a correlation coefficient of R2 > 0.85. The energy proportion of the infrasound signal from 0 to 0.12Hz exceeds 80 %. And as the CSC stage progresses, the energy of infrasound waves in the 0.04–0.08Hz frequency band increases significantly, and the changes in infrasound signals in this frequency band have a good correlation with temperature, with a correlation coefficient above 0.8. This frequency band is the main frequency band of infrasound waves during the CSC process. The research in this article provides a theoretical basis for the application of infrasound wave monitoring and warning of coal energy spontaneous combustion, and it is of great significance to ensure the safe mining of coal energy.