Disturbances of Air Parameters Caused by the Operation of the Shearer in the Longwall
Stanislaw Wasilewski, The Strata Mechanics Research Institute of the Polish Academy of Sciences,
Air parameter monitoring systems, regardless of gasometric protections, provide a significant number of measurement data. The obtained data broaden the knowledge on processes taking place in underground workings and show the relationships and influence of machines and technological processes on the variability of ventilation parameters in the areas of longwalls. Nowadays, computer simulation methods are increasingly used to reproduce the flow of air and methane mixture in the area of longwalls equipped with shearers. The paper presents the results of a research experiment covering a long-term observation of a longwall area during mining with a shearer using sensors of the mine's automatic gasometry system. Data from sensors for methane concentration, pressure and velocity were used and additional ventilation measurements were taken to determine the parameters characterizing the air flow in the area. The influence of different machine cycles in the longwall on the changes of air parameters in the area of the longwall was shown. A numerical model of the ventilation area was developed and a computer program VentZroby was used for the calculations, which allows for simulation of the process of ventilating the area of the active longwall during coal extraction with the use of a shearer and haulage of the run-of-mine. Computer simulation of the influence of the shearer's operation and the methane inflow associated with the distribution of the mixture of air and methane was carried out. The results of the simulation were compared with the data recorded by the sensors of the monitoring system during the measurement experiment. Comparison of the recorded methane concentration courses with the results of a computer simulation of the air and methane flow conditions in the mining area showed changes in the gassiness.