The Fifth International Symposium on Mine Safety Science and Engineering (ISMSSE2021)

51 / 2021-08-30 21:11:14

Increasing the Operating Speed of the Tools for Controlling the Explosion Hazard of Mine Workings in Mines

sudden outbursts,methane,thermocatalytic measurement method,mine workings,mine,coal

The paper discusses that one of the most dangerous phenomena leading to the formation of explosive gas mixtures are sudden outbursts of coal, rock and gas. During emissions, the methane content in mine working can reach 100% in a relatively short period of time. The rate of increase in the methane content in the mine in this case reaches 5%/s. Since almost all existing tools of controlling the explosion hazard of mine workings in mines, which are used in automatic gas control systems, are based on a relatively inertial thermocatalytic measurement method, the issue of increasing their operating speed is an urgent task. The research results aimed at improving the reliability of gas control equipment have been analyzed. It has been substantiated that it is possible to increase the operating speed and reliability of the automatic gas control equipment by simultaneously using two sensors in methane analyzers. Moreover, the main one should be a highly stable, but relatively inertial thermocatalytic sensor, and the auxiliary one should be a low-inertia optical or ultrasonic sensor. In this case, the output signal of the main sensor is used to generate a remote measurement signal, a signal for a power cutoff, and adjust the low-inertia sensor output signal. The auxiliary sensor generates a signal for a power cutoff when an unacceptable methane concentration and unacceptable rate of change in the methane concentration are reached. Based on the possible rate of change in the low-inertia sensor output signal, which is caused by the influence of uncontrolled parameters, the required rate of output signal adjustment of the low-inertia sensor has been determined. It has been proven that when setting the low-inertia sensors in a zone where they can be exposed to emission products, preference should be given to optical absorption sensors, since the presence of foreign objects in their measuring volume unambiguously leads to protective shutoff system actuation.