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Sustained Hydrogen Leak Concentration in Enclosure with One Vent

Molkov, Vladimir, Shentsov, Volodymyr and Quintiere, James (2013) Sustained Hydrogen Leak Concentration in Enclosure with One Vent. In: Seventh International Seminar on Fire & Explosion Hazards (ISFEH7), Providence, RI, USA. University of Maryland. Research Publishing.. (111) 8 pp. [Conference contribution]

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URL: http://rpsonline.com.sg/proceedings/9789810759360/html/111.xml

DOI: 10.3850/978-981-07-5936-0_14-03

Abstract

An analytical model for a steady-state hydrogen concentration during a sustained leak in a passively ventilated enclosure with one rectangular vent is described. An equation for hydrogen concentration in vented enclosure as a function of a leak volumetric flow rate is derived in the assumption of perfect mixing. The predictions by this equation are compared against the experimental data on helium release in 0.97 m3 volume enclosure and predictions by currently used equation based on the assumptions of natural ventilation of air in buildings. It is underlined that equations derived for natural air ventilation in buildings, which are often built on the equality of volumetric flow rate in and out of the enclosure through a single vent, are not applicable to the design of passive ventilation systems intended to tackle unscheduled hydrogen releases. The difference in concentration predicted by the former natural ventilation equation and the equation for passive ventilation derived here can be as large as ±2 times that has serious safety implications. The developed model predicted the maximum concentrations of helium measured in experiments fairly good in the whole range of test conditions. It can be recommended as a conservative engineering tool for hydrogen safety engineering even for scenarios with non-uniform hydrogen distribution in enclosure with one vent. Besides, an equation for a mass flow rate limit that leads to 100% of hydrogen concentration in a vented enclosure is presented and discussed.

Item Type:Conference contribution (Paper)
Faculties and Schools:Faculty of Art, Design and the Built Environment
Faculty of Art, Design and the Built Environment > School of the Built Environment
Research Institutes and Groups:Built Environment Research Institute
Built Environment Research Institute > Hydrogen Safety Engineering and Research Centre (HySAFER)
ID Code:29821
Deposited By: Mr Volodymyr Shentsov
Deposited On:07 Aug 2014 11:30
Last Modified:07 Aug 2014 11:30

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