In this paper we focus on the term "Explosion", and its definitions from a societal, regulatory and scientific perspective. The experts involved in developing Regulations, Codes and Standards (RCS) are typically not combustion scientists. Conversely, combustion scientists are typically not involved in development of RCS. Yet, both sets of experts develop literature applicable to explosions. There are aspects, particularly related to the definitions associated with explosions, where improved consistency would be beneficial.
Hydrogen non-premixed combustion in enclosure with one vent and sustained release: Numerical experiments
Numerical experiments are performed to understand different regimes of hydrogen nonpremixed combustion in an enclosure with passive ventilation through one horizontal or vertical vent located at the top of a wall. The Reynolds averaged Navier Stokes (RANS) computational fluid dynamics (CFD) model with a reduced chemical reaction mechanism is described in detail.
Based on the increasing need of energy for the future and the related risks to the environments due to burning of fossils fuels, hydrogen is seen as an efficient and application related clean energy carrier that may be derived from renewable energy sources.
The response of a typical steel-lined reinforced concrete nuclear reactor containment to postulated internal hydrogen detonations is investigated by detailed axisymetric non-linear dynamic finite element analysis. The wall pressure histories are calculated for hydrogen detonations using a technique that reproduces the sharp discontinuity at the shock front. The pressure results can be applied to geometrically similar vessels. The analysis indicates that the response is more sensitive to the point of initiation than to the strength of the detonation.
In the summer of 1985 a severe hydrogen-air explosion occurred in an ammonia plant in Norway. The accident resulted in two fatalities and the destruction of the building where the explosion took place. This paper presents the main findings from an investigation in 1985 and 1986 of the gas explosion and its consequences. The event started when a gasket in a water pump was blown out. The water pump was situated inside a 100 m long, 10 m wide, and 7 m high building. The pump was feeding water to a vessel containing hydrogen gas at pressure of 30 bars.
This paper shows the experimental results and findings of field explosion tests conducted to obtain fundamental data concerning the explosion of hydrogen-air mixtures. A tent covered with thin plastic sheets was filled with hydrogen/air mixed gas, and subsequently ignited by an electric-spark or explosives to induce deflagration and/or detonation. Several experiments with different concentrations and/or volumes of mixture were carried out. The static overpressure of blast waves was measured using piezoelectric pressure sensors.
1D Phenomenological Model Estimating the Overpressure Which Could Be Generated By Gas Explosion in a Congested Space
A phenomenological approach is developed to calculate the velocity of flame propagation and to estimate the value of pressure peak when igniting gaseous combustible mixtures in a congested space. The basic idea of this model is afterburning of the remanent fuel in pockets of congested space behind the flame front. The estimation of probable overpressure peak is based on solution of one-dimensional problem of the piston (having corresponding symmetry) moving with given velocity in polytropic gas.
The following paper describes researches to evaluate the behavior under various accidental conditions of systems of transport compressed hydrogen. Particularly have been considered gaseous tube trailer and the packages cylinders employed for the road transport which have an internal gas pressures up to 200 barg. Further to a verification of the actual safety conditions, this analysis intends to propose a theme that in the next future, if confirmed projects around the employment of hydrogen as possible source energetic alternative, could become quite important.
Assessing the Durability and Integrity of Natural Gas Infrastructures for Transporting and Distributing Mixtures of Hydrogen and Natural Gas
Extensive infrastructure exists for the transport of natural gas and it is an obvious step to assess its use for the movement of hydrogen. The Naturalhy project s objective is to prepare the European natural gas industry for the introduction of hydrogen by assessing the capability of the natural gas infrastructure to accept mixtures of hydrogen and natural gas. This paper presents the ongoing work within both Durability and Integrity Work Packages of the Naturalhy project.
Hydrogen is not more dangerous than current fossil energy carriers, but it behaves differently. Therefore hydrogen specific analyses and countermeasures will be needed to support the development of safe hydrogen technologies. A systematic step-by-step procedure for the mechanistic analysis of hydrogen behaviour and mitigation in accidents is presented.