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The effects of a gas explosion in enclosures like vessels can be limited e.g. by gas explosion venting
systems. The major design step of this constructive explosion protection method is to determine the
required vent area, which depends significantly on whether turbulent combustion exists. However,
current standards like NFPA 68 or EN 14994 are applicable only to limited boundary conditions and
as far as possible only to laminar flame propagation. Difficulties arise in the assessment or predictability
of gas explosion hazard when turbulence occurs.
In this research especially venting at elevated initial pressure has been shown to accelerated
flame propagations and therefore, to a considerably higher reduced pressure. Therefore, it is essential
to provide a broader data base of turbulent combustion and explosion behaviour to verify the
existing rules or to determine their safety-relevant parameters.
For a better safety assessment or design of protective systems the turbulent combustion and
accelerated gas explosion behaviour of quiescent methane in air were investigated at initial pressures
up to 8 bar using vessels up to 100 litres. In particular a systematic study was performed to
investigate the influence of turbulence on the overpressure development during accelerated gas
explosion. Moreover, the present study consider the position of the spark igniters, the burning velocity
and the maximum pressure rise for different concentration of fuel as well as the size of orifice
and/or vent area.
A choice of experimental tests showed under the investigated conditions that not only turbulence
inducing obstacles but also over sized vent areas could lead to an increased pressure development
and therefore to an inacceptable safety state. Due to the numerous influencing variables of
explosion behaviour the presented experimental results help to judge whether another more sophisticated
method should be applied than the one described in standards.
The effects of a gas explosion in enclosures like vessels can be limited e.g. by gas explosion venting systems. The major design step of this constructive explosion protection method is to determine the required vent area, which depends significantly on whether turbulent combustion exists. However, current standards like NFPA 68 or EN 14994 are applicable only to limited boundary conditions and as far as possible only to laminar flame propagation. Difficulties arise in the assessment or predictability of gas explosion hazard when turbulence occurs. In this research especially venting at elevated initial pressure has been shown to accelerated flame propagations and therefore, to a considerably higher reduced pressure. Therefore, it is essential to provide a broader data base of turbulent combustion and explosion behavior to verify the existing rules or to determine their safety-relevant parameters. For a better safety assessment or design of protective systems the turbulent combustion and accelerated gas explosion behaviour of quiescent methane and hydrogen in air were investigated at initial pressures up to 8 bar using vessels up to 100 litres. In particular a systematic study was performed to investigate the influence of turbulence on the overpressure development during accelerated gas explosion. Moreover, the present study consider the position of the spark igniters, the burning velocity and the maximum pressure rise for different concentration of fuel as well as the size of orifice and/or vent area. A choice of experimental tests showed under the investigated conditions that not only turbulence inducing obstacles but also over sized vent areas could lead to an increased pressure development and therefore to an inacceptable safety state.