Effect of Radiative Heat Transfer on the Structure and Propagation of Layered Coal-Dust Explosions

Details

• Personal Author:
  Guhathakurta S
• Description:
  Multidimensional unsteady numerical simulations were carried out to explore the influence of thermal radiation on the propagation and structure of layered coal dust explosions. The simulations solved the reactive compressible Navier-Stokes equations coupled to an Eulerian kinetic-theory-based granular multiphase model. The radiation heat transfer is modeled by solving the radiation transfer equation using the third-order filtered spherical harmonics approximation. The radiation was assumed to be gray and all boundaries of the domain are black at 300 K. The reaction mechanism is based on global reactions for each physical process including devolatilization, char burning, moisture vaporization, and methane combustion. The governing equations were solved using a high-order Godunov method. Several simulation configurations were considered: layer volume fractions of 47% and 1%, channel lengths of 10 m and 40 m, single and two-step reaction mechanisms, several particle sizes, and radiative and non-radiative cases. The results show that gray radiation significantly influences the propagation and structure of a layered dust explosion. However, radiation can have opposite effects on different scenarios. For example, using the single-step reaction mechanism, radiation promotes the propagation of the dust flame when the layer volume fraction was 1\% and in the short-channel cases where reflected shock-flame interactions are important. However, radiation enhances quenching for the 47% volume fraction dust layer in the longer channel. When using the two-step reaction mechanism, radiation enhances flame propagation and explosion severity in almost all test cases where the particles are easy to ignite. On the other hand, it seems to quench or slow down the flame propagation through radiative heat loss for particles that are hard to ignite. [Description provided by NIOSH]
• Subjects:
  Occupational Health Safety
• Keywords:
  Coal Dust Dust Explosions Explosion Damage Explosive Dusts Simulation Methods Thermal Radiation
• Publisher:
  University of Florida
• Document Type:
  Text
• Funding:
  Contract
• Genre:
  Dissertation
• Place as Subject:
  Florida ; Maryland ; OSHA Region 3 ; OSHA Region 4
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-183
• NIOSHTIC Number:
  nn:20068956
• Citation:
  Gainesville, FL: University of Florida, 2021 Aug; :1-183
• Federal Fiscal Year:
  2021
• Performing Organization:
  University of Maryland
• Peer Reviewed:
  False
• Start Date:
  20150901
• Source Full Name:
  Effect of radiative heat transfer on the structure and propagation of layered coal-dust explosions
• End Date:
  20180831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:99864a1df37e10f28f716cf5c8b958c76202d7f6c82f108d0c2edab4f2ebfdf058d01392e7dbbf9a2df2fa3fb6f29755937b897a123c83ca8f41d21dfeb71f28
• Download URL:
  https://stacks.cdc.gov/view/cdc/207513/cdc_207513_DS1.pdf
• File Type:
  [PDF - 35.38 MB ]