Gob Location and the Propagation of Methane Flames in Simulated and Experimental Flame Reactors

Details

• Personal Author:
  Bogin G Jr. ; Brune, Jürgen F. ; Fig M ; Strebinger C
• Description:
  A knowledge of flame propagation characteristics through and around obstacles is needed to accurately model methane-air longwall coal mine explosions originating or propagating in and around the gob. Researchers at the Colorado School of Mines (CSM) conducted experimental investigations of methane flames in horizontal reactors with simulated gob rock piles. Researchers also carried out coupled, computational fluid dynamics (CFD) and combustion simulations using ANSYS Fluent. Stoichiometric methane-air mixtures were ignited in semi-open experimental reactor vessels of 5cm, 9.5cm and 71cm diameter, all with a fixed length to diameter (L/D) ratio of 8.6. Rock pile length was fixed at 30% of the length of the reactor and rock pile height was fixed at 33% of the diameter of the reactor for direct comparison between reactor vessels across scales. This paper presents results for three reactor configurations: empty reactors, reactors with a rock pile placed at the open end, and reactors with a rock pile at the closed end. Experimental results indicate that flame acceleration depends on pile location and geometry as well as size of the reactor. In the 5cm diameter reactor, the rock pile at the open end of the reactor produced the fastest flame, whereas in the larger reactors, a rock pile at the closed end of the reactor produced the fastest flame. A 2D, CFD combustion model accurately captures the general trends observed in experiments for the smaller reactors but over predicts the magnitude of methane flame front propagation velocity. [Description provided by NIOSH]
• Subjects:
  Explosions Mining Occupational Health Safety
• Keywords:
  Coal Mines Explosive Gases Longwall Mining Methane Drainage Mine Fires Underground Mines
• Publisher:
  Society for Mining, Metallurgy, and Exploration, Inc.
• Document Type:
  Text
• Funding:
  Contract
• Genre:
  Proceedings
• Place as Subject:
  Colorado ; OSHA Region 8
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-6
• NIOSHTIC Number:
  nn:20068392
• Citation:
  2019 SME Annual Meeting, February 24-27, 2019, Denver, Colorado, preprint 19-117. Englewood, CO: Society for Mining, Metallurgy, and Exploration, Inc., 2019 Feb; :1-8
• CAS Registry Number:
  Methane (CAS RN 74-82-8)
• Federal Fiscal Year:
  2019
• Performing Organization:
  Tustees of the Colorado School of Mines
• Peer Reviewed:
  False
• Start Date:
  20140901
• Source Full Name:
  2019 SME Annual Meeting, February 24-27, 2019, Denver, Colorado, preprint 19-117
• End Date:
  20190831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:24731acbe1b31f87b7e09664ccf295205b2b70bd455501dff04e74bf3bd981b42f848351fbe83bd456e66517bc8d55a73ffacba1833fc9fe265f680ba2303bd3
• Download URL:
  https://stacks.cdc.gov/view/cdc/230551/cdc_230551_DS1.pdf
• File Type:
  [PDF - 991.22 KB ]