Thermal radiation induced ignition of multipoint turbulent explosions
File(s)Tao_Li_Accepted.pdf (7.5 MB)
Accepted version
Author(s)
Li, T
Lindstedt, RP
Type
Journal Article
Abstract
The severity of vapour cloud explosions is typically correlated with the peak over-pressure or, more accurately, with the total impulse caused by the pressure waves. The flame speed arising from strong (e.g. quasi-stable) turbulent deflagrations is frequently used to provide an indication of potential damage. However, conventional flame propagation mechanisms can present difficulties in terms of explaining the resulting damage. For example, the over-pressure in the Buncefield vapour cloud explosion was much higher than that predicted by conventional models. Alternative propagation mechanisms include intermittent localised strong explosions or detonations potentially supported by forward thermal radiation causing multi-point ignition of dust particles ahead of the advancing flame front. Such mechanisms are here explored using particles coated with acetylene black as the radiation target due to their relationship with soot emissions. A continuous wave laser operating in the near infrared was used as the radiation source with experiments performed in a flame tube using fuel lean CH4/H2/Air mixtures. It is shown that ignition kernels caused by irradiated particles can successfully be entrained into the main flow and/or recirculation zones formed around obstacles and cause multipoint explosions. The resulting relationship between fuel consumption ahead of the advancing flame and the evolution of the strength of the explosion is shown to be complex and typically lead to increased explosion durations with reduced peak pressures. It is also shown that chaotic pressure wave interactions can substantially increase both the explosion duration and the peak pressure depending on the timing of the radiation induced ignition.
Date Issued
2017-02-09
Date Acceptance
2017-01-30
Citation
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION, 2017, 107 (April 2017), pp.108-121
ISSN
0957-5820
Publisher
Institution of Chemical Engineers
Start Page
108
End Page
121
Journal / Book Title
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
Volume
107
Issue
April 2017
Copyright Statement
© 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000401201200011&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Technology
Engineering, Environmental
Engineering, Chemical
Engineering
Turbulent explosions
Particle ignition
Thermal radiation
Natural gas
Hydrogen enrichment
Pressure impulse
FLAME ACCELERATION
OBSTACLES
DEFLAGRATION
DETONATION
TRANSITION
PARTICLES
MIXTURES
PROPAGATION
DEPENDENCE
BUNCEFIELD
Strategic, Defence & Security Studies
0904 Chemical Engineering
Publication Status
Published