Title: CFD modelling of nitrogen injection in a longwall gob area

Authors: Liming Yuan; Alex C. Smith

Addresses: Office of Mine Safety and Health Research, National Institute for Occupational Safety and Health, P.O. Box 18070, Cochrans Mill Road, Pittsburgh, PA 15236, USA ' Office of Mine Safety and Health Research, National Institute for Occupational Safety and Health, P.O. Box 18070, Cochrans Mill Road, Pittsburgh, PA 15236, USA

Abstract: This paper describes computational fluid dynamics (CFD) simulations conducted to investigate the effectiveness of N₂ injection in an active panel and a sealed longwall gob area to prevent and suppress spontaneous heating of coal using various injection locations and flow rates. In the active panel simulations, a single longwall panel with a bleederless ventilation system was simulated. The spontaneous heating of crushed coal from pillars was simulated and N₂ was injected from different locations on the headgate side and through boreholes from the surface. The N₂ injection rate at each location was varied between 0.18 m³/s and 0.94 m³/s (380 and 2000 cfm). In the sealed longwall simulations, seal leakage rate was varied to determine its effect on N₂ injection effectiveness. The results of this study should aid mine ventilation engineers in developing more effective N₂ injection strategies to prevent and control spontaneous heating of coal in underground coal mines.

Keywords: spontaneous combustion; longwall gob; CFD modelling; computational fluid dynamics; simulation; nitrogen injection; ventilation system; flow rates; coal mining; bleederless ventilation; mine ventilation; underground mines.

DOI: 10.1504/IJMME.2014.060220

International Journal of Mining and Mineral Engineering, 2014 Vol.5 No.2, pp.164 - 180

Received: 21 Jan 2013
Accepted: 06 Sep 2013
Published online: 10 Sep 2014 *

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