Initial assessment of the impact of jet flame hazard from hydrogen cars in road tunnels

As the development of hydrogen cars advancing into the markets, it is unavoidable in the near future that hydrogen cars would become the users of ordinary road tunnels. This paper carried out an initial examination of potential fire scenarios and fire hazards from worst possible cases of hydrogen release in road tunnels and implications on the fire safety measures and ventilation systems in existing tunnels. Due to the low ignition energy and wide flammable range, hydrogen leaks have a high probability of ignition and result hydrogen jet flames. CFD simulations of hydrogen jet flame in a full scale 5m by 5m square cross-section tunnel were carried out. The effect of the ventilation on controlling the upstream backlayering and the downstream flame were discussed. The results showed that the impact of hydrogen flame in the tunnel depended on the hydrogen release rate. The tunnel ventilation system could eliminate the upstream backlayering and fully control downstream flame with a smaller hydrogen release rate. For a larger hydrogen release, the tunnel ventilation system couldn't provide sufficient air flow into the fire and there is an oxygen deficit hydrogen layer accumulating under the ceiling downstream of the fire. The accumulating hydrogen layer could pose more serious hazards inside the tunnel (A). For the covering abstract of the conference se ITRD E216860.


  • English

Media Info

  • Pagination: pp71-79
  • Monograph Title: Proceedings from the Third International Symposium on Tunnel Safety and Security, Stockholm, Sweden, March 12-14 2008
  • Serial:
    • Issue Number: 2008:11
    • Publisher: SP Sveriges provnings- och forskningsinstitut, Sweden
    • ISSN: 0284-5172

Subject/Index Terms

Filing Info

  • Accession Number: 01141064
  • Record Type: Publication
  • Source Agency: Swedish National Road and Transport Research Institute (VTI)
  • ISBN: 978-91-85829-25-5
  • Files: ITRD
  • Created Date: Sep 30 2009 8:59AM