Recovery of the Scenario of Explosive Accident Development by Calculated Method


Annotation:

The consequences of a real explosive accident are considered in the article. The scenario of its development is restored based on the available data. The need for a detailed study is caused by the fact that initially the main version of the explosion and fire occurrence was a methane leak from the gas pipeline at the enterprise. Having examined the materials describing the accident consequences and considering the experience of such explosive accident investigation, it became obvious that the main cause of the explosion and fire was the emergency rupture of the propane cylinder. Four stages that accompanied gas cylinder emergency rupture are examined in detail: cylinder rupture accompanied by a characteristic sound; discharge into the room of an overheated liquid located in the cylinder in the form of a vapor mixture with small drops of liquid; explosive combustion of a propane-air mixture framing an ejection jet; fire storm spreading throughout the room.

Numerical calculations of the last two stages of accident development showed that the generated explosion pressure in the emergency room corresponds to the destructions that occurred, and the heat load corresponds to the burns received by the witnesses of emergency explosion.

For example, the initial stage of explosive combustion was accompanied by a short-term explosive load (lasting about 20–50 ms), which had a pronounced wave character. The maximum amplitude of the explosive pressure was approximately 5 kPa. A dynamic load with the indicated parameters can cause partial damage to the building structure and internal partitions, which occurred during the accident.

The resulting wind load also had a pronounced wave character and was perceived by others as a gust of wind. Wave flow velocities did not exceed 10–15 m/s, which corresponds to the concept of «gust of wind», that was indicated by the witnesses of the accident.

Comparison of the calculation results with the existing destructions and damages shows that the accidental explosion occurred according to the scenario adopted in the calculations.

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DOI: 10.24000/0409-2961-2020-8-7-13
Year: 2020
Issue num: August
Keywords : deflagration explosion pressure vessel superheated liquid fire ball physical explosion heat loads explosive accident accident scenario numerical calculation calculation method
Authors:
  • Komarov A.A.
    Dr. Sci. (Eng.), Prof., Head of the Explosion Safety Research Center NRU MGSU, Moscow, Russia
  • Gromov N.V.
    Cand. Sci. (Eng.), Deputy Director Moscow State University of Civil Engineering, Moscow, Russia
  • Bazhina E.V.
    Cand. Sci. (Eng.), Assoc. Prof. National Research Moscow State University of Civil Engineering, Moscow, Russia