L'utilsation et le stockage de grandes quantites de gaz inflammables dans l'industrie chi... more L'utilsation et le stockage de grandes quantites de gaz inflammables dans l'industrie chimique et dans les raffineries constituent pour l'environnement un risque potentiel d'explosion. En particulier, dans les regions ou la densite de population est elevee et ou les installations industrielles sont proches des zones urbaines, les risques de dommage importants en cas d'explosion accidentelle sont significatifs. AutoReaGas est un code C.F.D. (Computational Fluid Dynamics) qui permet de simuler l'ensemble des phenomenes mis en jeu lors d'une explosion de gaz. Ce code comprend en particulier deux modeles concus specifiquement pour simuler la combustion des gaz d'une part et la propagation des ondes de souffle d'autre part. Dans cet article, l'emploi d'AutoReaGas est illustre dans un cas pratique.
In retreating faces, dilution of firedamp flowing out of the goaf area at the junction of face an... more In retreating faces, dilution of firedamp flowing out of the goaf area at the junction of face and retum roadway is problematic. Despite important flowrates and high CH4 drainage efficiencies, it has been observed that 2/3 of firedamp evacuated by the air stream concentrate in this particular place. So äs to progress in preventing such difficulties, it is necessary to better understand the repartition of gas fluxes in the goaf. This has obviously a benefit on firedamp drainage efficiency, but also on the choice of nitrogen injection points and flowrates in case of spontaneous combustion in the goaf. The use of a CFD code, PHOENICS, has allowed Simulation of circulation of three gases: air, CH4, and N2. Influence of the face dip on the repartition of CH4 pattems in the goaf area has been qualitatively demonstrated.
Various investigators noted that very significant explosions could result from the formation and ... more Various investigators noted that very significant explosions could result from the formation and ignition of a large combustible cloud following from a primary vented explosion. This phenomenon is sometimes referred to as " secondary explosion ". A systematic full scale experimental work (with vessel sizes ranging from 1 m3 to 100 m3 mixture of methane, propane and hydrogen with air) has been performed over a period of several years to understand better the underlying physics. Surprising results were obtained showing for instance that near the vent the maximum overpressure may be lower than further downstream not because the external explosion is developing far downstream but because of the local influence of rarefaction waves produced at the vent. With help of high speed videos the nature and characteristics of the external cloud has been understood and the type of combustion studied. With this knowledge the nature of the interaction with the internal explosion has been c...
A terrible explosion of ammonium nitrate occurred on 21st September 2001, in Toulouse, in AZF pla... more A terrible explosion of ammonium nitrate occurred on 21st September 2001, in Toulouse, in AZF plant belonging to Grande Paroisse Company, TotalFinaElf Group. The manufactured chemicals in the plant were mainly ammonium nitrate, ammonium nitrate-based fertilisers and other chemicals including chlorinated compounds. The explosion took place in a storage warehouse where roughly 400 tons of rejected off-spec materials were stored. The TNT equivalent mass of the explosion was estimated by INERIS in a range of 20 to 40 tons of TNT. The human effects of the explosion were 30 persons killed and up to 2242 people injured. The plant was located in the suburbs of Toulouse and the extent of damages was very large both on and off site with a cost estimated by insurers of 1.5 billion Euro. The first aim of this paper is to provide, outside France, information on the damages of this case history, with particular emphasis on estimates of the explosion strength's, on damages and human effects da...
Gas explosions constitute a major hazard for offshore gas and oil producing installations. A gas ... more Gas explosions constitute a major hazard for offshore gas and oil producing installations. A gas explosion is the consequence of an accidental release of a flammable gas, the mixing with air and a subsequent ignition. Under appropriate boundary conditions the resulting flame propagation process may develop explosive combustion and damaging blast loadings. In spaces containing a lot of equipment, this is a particular problem and a small quantity of fuel may be sufficient to give rise to the development of high explosion overpressures. If such overpressures are not anticipated in the design they may have fatal consequences for both crew and rig.
Early in the morning on October the 7th 1991, the town of Nantes (Westem France) was shaken by a ... more Early in the morning on October the 7th 1991, the town of Nantes (Westem France) was shaken by a deflagration. This vapour cloud explosion (VCE) occurred m a petroleum depot. This was not the first accident in such a configuration but, probably in France, the one which produced the most extensive damage to the surroundings. For instance, numerous windowpanes were broken in a 2 kilometer radius.
L'utilsation et le stockage de grandes quantites de gaz inflammables dans l'industrie chi... more L'utilsation et le stockage de grandes quantites de gaz inflammables dans l'industrie chimique et dans les raffineries constituent pour l'environnement un risque potentiel d'explosion. En particulier, dans les regions ou la densite de population est elevee et ou les installations industrielles sont proches des zones urbaines, les risques de dommage importants en cas d'explosion accidentelle sont significatifs. AutoReaGas est un code C.F.D. (Computational Fluid Dynamics) qui permet de simuler l'ensemble des phenomenes mis en jeu lors d'une explosion de gaz. Ce code comprend en particulier deux modeles concus specifiquement pour simuler la combustion des gaz d'une part et la propagation des ondes de souffle d'autre part. Dans cet article, l'emploi d'AutoReaGas est illustre dans un cas pratique.
In retreating faces, dilution of firedamp flowing out of the goaf area at the junction of face an... more In retreating faces, dilution of firedamp flowing out of the goaf area at the junction of face and retum roadway is problematic. Despite important flowrates and high CH4 drainage efficiencies, it has been observed that 2/3 of firedamp evacuated by the air stream concentrate in this particular place. So äs to progress in preventing such difficulties, it is necessary to better understand the repartition of gas fluxes in the goaf. This has obviously a benefit on firedamp drainage efficiency, but also on the choice of nitrogen injection points and flowrates in case of spontaneous combustion in the goaf. The use of a CFD code, PHOENICS, has allowed Simulation of circulation of three gases: air, CH4, and N2. Influence of the face dip on the repartition of CH4 pattems in the goaf area has been qualitatively demonstrated.
Various investigators noted that very significant explosions could result from the formation and ... more Various investigators noted that very significant explosions could result from the formation and ignition of a large combustible cloud following from a primary vented explosion. This phenomenon is sometimes referred to as " secondary explosion ". A systematic full scale experimental work (with vessel sizes ranging from 1 m3 to 100 m3 mixture of methane, propane and hydrogen with air) has been performed over a period of several years to understand better the underlying physics. Surprising results were obtained showing for instance that near the vent the maximum overpressure may be lower than further downstream not because the external explosion is developing far downstream but because of the local influence of rarefaction waves produced at the vent. With help of high speed videos the nature and characteristics of the external cloud has been understood and the type of combustion studied. With this knowledge the nature of the interaction with the internal explosion has been c...
A terrible explosion of ammonium nitrate occurred on 21st September 2001, in Toulouse, in AZF pla... more A terrible explosion of ammonium nitrate occurred on 21st September 2001, in Toulouse, in AZF plant belonging to Grande Paroisse Company, TotalFinaElf Group. The manufactured chemicals in the plant were mainly ammonium nitrate, ammonium nitrate-based fertilisers and other chemicals including chlorinated compounds. The explosion took place in a storage warehouse where roughly 400 tons of rejected off-spec materials were stored. The TNT equivalent mass of the explosion was estimated by INERIS in a range of 20 to 40 tons of TNT. The human effects of the explosion were 30 persons killed and up to 2242 people injured. The plant was located in the suburbs of Toulouse and the extent of damages was very large both on and off site with a cost estimated by insurers of 1.5 billion Euro. The first aim of this paper is to provide, outside France, information on the damages of this case history, with particular emphasis on estimates of the explosion strength's, on damages and human effects da...
Gas explosions constitute a major hazard for offshore gas and oil producing installations. A gas ... more Gas explosions constitute a major hazard for offshore gas and oil producing installations. A gas explosion is the consequence of an accidental release of a flammable gas, the mixing with air and a subsequent ignition. Under appropriate boundary conditions the resulting flame propagation process may develop explosive combustion and damaging blast loadings. In spaces containing a lot of equipment, this is a particular problem and a small quantity of fuel may be sufficient to give rise to the development of high explosion overpressures. If such overpressures are not anticipated in the design they may have fatal consequences for both crew and rig.
Early in the morning on October the 7th 1991, the town of Nantes (Westem France) was shaken by a ... more Early in the morning on October the 7th 1991, the town of Nantes (Westem France) was shaken by a deflagration. This vapour cloud explosion (VCE) occurred m a petroleum depot. This was not the first accident in such a configuration but, probably in France, the one which produced the most extensive damage to the surroundings. For instance, numerous windowpanes were broken in a 2 kilometer radius.
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