Risk identification of coal spontaneous combustion in goaf based on variable weight grey target model

Abstract

ABSTRACT Accurately determining the risk level of coal spontaneous combustion (CSC) in goaf is very important for coal mine safety production. In this paper, bituminous coal in Shanjiaoshu Coal Mine (SJS) was used as the research object to conduct a simulated spontaneous combustion experiment of coal with programmed heating. The results show that according to the characteristic temperature of CSC combined with the Graham R2 coefficient and the degree of spontaneous combustion and oxidation, the risk level of CSC in SJS Coal Mine is classified into four risk levels: low risk, general risk, greater risk, and major risk. Based on the grey target theory and grey entropy correlation analysis method, the equilibrium function is introduced to determine the variable weight of evaluation indexes and the risk grade judgment method of CSC in goaf. Based on the variable weight grey target model is established. The bull’s-eye distance corresponding to each risk level were 0 ~ 0.0052, 0.0052 ~ 0.1455, 0.1455 ~ 0.9554, and >0.9554, respectively. The verification results of the model based on the data of 6 groups of 12 measuring points of the beam tube monitoring system in SJS are consistent with the actual risk level.