Safety barrier of electrical equipment for environments with a potential explosion in underground coal mines

Titu Niculescu¹, Victor Arad¹, Marius Marcu¹, Susana Arad¹, Florin Gabriel Popescu¹

¹University of Petrosani, Petrosani, Romania

Min. miner. depos. 2020, 14(3):78-86

https://doi.org/10.33271/mining14.03.078

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ABSTRACT

Purpose. Electrical equipment for explosion-threatening environments in mines at risk of explosion communicates with the external environment through intrinsic safety barriers that limit the values of currents to values below the methane ignition, limit that exceeds the allowable concentration in the atmosphere. This avoids work accidents due to under-ground explosions, avoiding the risk of explosion through electric equipment.

Methods. Experimental research has been based on the geomechanical characterization of the coal and surrounding rocks in the Jiu Valley Basin and measurements obtained in situ was researched by statistic methods. Three methods of studying barriers based on the use of the MATLAB program were used. The first method is based on MATLAB programming, the second involves the barrier study using the Simulink model and the third method is based on the use of the SimPowerSystems software package. In all three cases studied, the variation of the voltage at the output of the barrier and current through the barrier are analyzed considering two operating modes, the aperiodic and the oscillating regimes.

Findings. The paper is a study of the intrinsic security barriers, based on which a correct dimensioning can be made.

Originality.The originality of the paper consists in the analysis of the barriers with intrinsic safety, using the simulation with the MATLAB-Simulink program packages.

Practical implications. All the methods addressed lead to obtaining the diagrams of variation of the voltage at the exit of the barrier and of the current through the barrier in two possible regimes: the aperiodic regime and the oscillating regime.

Keywords: coal mining, explosive environment, gas explosions, geomechanical parameters, methane, security barrier

REFERENCES

Arad, V., Arad, S., Samoila, L., & Teseleanu, G. (2019). The coal exploitation in the Jiu Valley between the strategic resource and social impact. Journal of Engineering Sciences and Innovation, 4(1), 99-114.
Bondarenko, V., Symanovych, G., & Koval, O. (2012). The mechanism of over-coal thin-layered massif deformation of weak rocks in a longwall. Geomechanical Processes During Underground Mining, 41-44.https://doi.org/10.1201/b13157-8
Falshtynskyi, V., Dychkovskyi, R., Lozynskyi, V., & Saik, P. (2013). Determination of the technological parameters of borehole underground coal gasification for thin coal seams. Journal of Sustainable Mining, 12(3), 8-16.https://doi.org/10.7424/jsm130302
Suvar, M.C., Cioclea, D., Arad, V., Lupu, C., & Vlasin, N.I. (2017). Method for improving the management of mine ventilation networks after an explosion. Environmental Engineering and Management Journal, 16(6), 1373-1381.https://doi.org/10.30638/eemj.2017.148
Simon, A.B., Arad, S., & Samoila, L. (2017). Monitoring systems in explosive and potentially toxic environments for reducing risk factors. The Fifth International Symposium on Electrical and Electronics Engineering (ISEEE), 30-34.https://doi.org/10.1109/ISEEE.2017.8170647
Arad, V., Arad, S., Cosma, V.A., & Suvar, M. (2014). Gazodinamic regime on geomechanics point of view for Jiu Valley coal beds. Multidisciplinary Scientific GeoConference-SGEM, Geoconference on Science and Technologies in Geology, Exploration and Mining, (3), 269-276.https://doi.org/10.5593/SGEM2014/B13/S3.036
Pivnyak, G., Bondarenko, V., Kovalevs’ka, I., & Illiashov, M. (2012). Geomechanical Processes during Underground Mining. London, United Kingdom: CRC Press, Taylor & Francis Group, 238 p.https://doi.org/10.1201/b13157
Suvar, M.C., Lupu, C., Arad, V, Cioclea, D., Pasculescu, V.M., & Mija, N. (2014). Computerized simulation of mine ventilation networks for sustainable decision making process. Environmental Engineering and Management Journal, 13(6), 1445-1451.https://doi.org/10.30638/eemj.2014.159
Arad, V., Ilias, N., Achim, M., & Arad, S. (2011). Setting the drilling-blasting parameters depending on the geomechanics of rocks. Journal of Engineering Studies and Research, JESR, 17(3), 7-11.
Arad, V., Arad, S., Radermacher, L., Radeanu, C., & Popa, C. (2016). A correction coefficient of mechanical parameters of the Jiu Valley coal or rock test samples. International Multidisciplinary Scientific GeoConference-SGEM, (3), 15-19.https://doi.org/10.5593/SGEM2014/B13/S3.036
Popescu, F.G., Arad, S., Marcu, M., & Pana, L. (2013). Reducing energy consumption by modernizing drives of high capacity equipment used to extract lignite. International Multidisciplinary Scientific GeoConference-SGEM, Energy and Clean Technologies, 183-190.https://doi.org/10.5593/SGEM2013/BD4/S17.024
Liu, S., Wu, H., Zhang, Y., Hu, C., & Yan, J. (2019). The analysis and design of high-power intrinsic safe forward converter based on power-i technology. IOP Conference Series: Materials Science and Engineering, (533), 1-8.https://doi.org/10.1088/1757-899X/533/1/012015
Niculescu, T., Marcu, M., & Popescu, F. (2016). Study of switching electric circuits with DC hybrid breaker, one stage. IOP Conference Series: Materials Science and Engineering, (133), 012057.https://doi.org/10.1088/1757-899X/133/1/012057
Hu, W., Zhang, F., Xu, Y., & Chen, X. (2014). Output voltage ripple analysis and design considerations of intrinsic safety flyback converter based on energy transmission modes. Journal of Power Electronics, 14(5), 908-917.https://doi.org/10.6113/JPE.2014.14.5.908