(25b) Hydrogen Jet Vapor Cloud Explosion:  a Model for Predicting Blast Size and Application to Risk Assessment

Hydrogen Jet Vapor Cloud Explosion: 
A Model for Predicting Blast Size and Application to Risk Assessment

Simon Jallais and Elena Vyazmina

Air Liquide R&D

1 Chemin de la Porte des Loges - Les Loges-en-Josas

78354 JOUY-EN JOSAS

Simon.Jallais@AirLiquide.com,
Elena.Vyazmina@AirLiquide.com

Derek
Miller

Air Products

7201
Hamilton Boulevard

Allentown, PA 18195-1501
Millerd3@AirProducts.com

J.
Kelly Thomas, Ph.D.

Baker Engineering and Risk Consultants (BakerRisk)

3330 Oakwell Court, Suite 100

San Antonio, TX 
78218-3024

KThomas@BakerRisk.com

Releases of hydrogen at elevated
pressures form turbulent jets which may pose vapor cloud explosion (VCE) as
well as jet fire hazards.  The turbulence
induced by the jet release can lead to flame speeds sufficient to produce
damaging blast loads if the release is not immediately ignited, even in the
absence of confinement or congestion. 
The VCE hazard posed by such high pressure hydrogen releases is not
well-recognized.

The authors have previously presented
test data and computational fluid dynamic (CFD) modeling analyses which
characterize high pressure hydrogen releases and the associated VCE hazard.  The current paper provides an overview of
this VCE hazard, presents a simplified method for predicting the potential
resultant blast loads, and discusses the implications of such events for
building siting analyses and risk assessments.