Impact of coalbed incidence angle on methane enrichment zone in longwall gob
MetadataShow full item record
Â© 2017 by the authors. Licensee MDPI, Basel, Switzerland. To control methane emissions in gob into longwall working faces, it is necessary to understand the distributions of methane enrichment zones (MEZ) around mined coal seams with different incidence angles. In this paper, FLAC3D software is used to calculate the three-dimensional stress distributions in MEZ in gobs with coalbed incidence angles ranging from 0Â° to 50Â°. The results show that MEZ consistently exhibit a â€œhexagonâ€? shape, and rotate in a clockwise direction as the coalbed angle increases. The MEZ range above the mined seam is larger than that below the mined seam. As the coalbed angle increases, the MEZ range in the roof decreases, while the MEZ range in the floor increases. The MEZ height increases significantly as the coalbed angle increases. The MEZ widths in coal pillars of gobs increase slightly as the coalbed angle increases. The methane concentration increases exponentially as the height in the MEZ increases. The surface borehole bottoms located relatively higher in the MEZ can drain methane with a higher concentration and flow rate, as verified by a field test in the Pansan mine, China.
Showing items related by title, author, creator and subject.
Experimental investigation on variation of physical properties of coal particles subjected to microwave irradiationHu, G.; Yang, N.; Xu, Guang; Xu, J. (2017)The gas drainage rate of low-permeability coal seam is generally less than satisfactory. This leads to the gas disaster of coal mine, and largely restricts the extraction of coalbed methane (CBM), and increases the emission ...
Chamani, A.; Rasouli, Vamegh (2011)Coalbed methane (CBM) drew increasingly the attention as an unconventional source of natural gas during the last decades, globally and domestically. In spite of the fact that it is one of the main hazardous concerns in ...
Evolution Law of Adsorption and Desorption Characteristics of CH4 in Coal Masses during Coalbed Methane ExtractionTang, Z.; Yang, S.; Xu, Guang; Sharifzadeh, Mostafa; Zhai, C. (2018)The low-temperature oxidation of coal during coalbed methane extraction is inevitable. To study the evolution of the CH4 adsorption and desorption characteristics in coal masses during the low-temperature oxidation of ...