Definition of the form of coal spontaneous combustion source as the inverse problem of geoelectrics

Dmitry Sirota,Vadim Ivanov,Veniamin Khyamyalyaynen,M Tyulenev,M Cehlar,A Khoreshok,S Zhironkin,S Voth,Y Tan

doi:10.1051/e3sconf/20171501012

Abstract

The paper reviews the method of determining the shape and size of the coal self-heating source on coal pit benches and in coal piles during mining of coal by the open method. The method is based on the regularity found in the 1970s of the previous century and related to the distribution of potential of the natural electrical field arising from the temperature in the vicinity of the center of self-heating. The problem is reduced to the solution of inverse ill-posed problem of mathematical physics. The study presents the developed algorithm of its solution and the results of numerical simulation.

Highlights

Spontaneous combustion of coal is one of the main causes of fires in open and underground development of coal seams
Geological and mining factors play a significant role in the process of spontaneous combustion of coal
Much less papers are devoted to development of algorithms for solving non-linear inverse problems [7,8,9,10,11]

Summary

Introduction

Spontaneous combustion of coal is one of the main causes of fires in open and underground development of coal seams. For control and diagnostics of the processes of self-heating and spontaneous combustion of coal it is required to promptly assess the power of the heat source, its size and shape. These parameters allow the proper positioning of the wells for injection of antipyrogens in the rock mass and their necessary volume in order to retard coal oxidation process. The theoretical basis of the process of coal self-heating control and definition of the form of the heat emitting source is detected in the 1970s steady relationship between the emergence of pockets of heat and the formation on the surface of coal accumulations of changes in the potential appearing in the process of self-heating of quasi-stationary electric field. Much less papers are devoted to development of algorithms for solving non-linear inverse problems [7,8,9,10,11]

Formulation and solution of the direct problem

Solution of the inverse problem

Algorithm

Implementation of a numerical