Sustained Hydrogen Leak Concentration in Enclosure with One Vent

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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.
LanguageEnglish
Title of host publicationUnknown Host Publication
Number of pages8
DOIs
Publication statusPublished - 10 May 2013
EventSeventh International Seminar on Fire & Explosion Hazards (ISFEH7) - Providence, RI, USA
Duration: 10 May 2013 → …

Conference

ConferenceSeventh International Seminar on Fire & Explosion Hazards (ISFEH7)
Period10/05/13 → …

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Vents
Enclosures
Ventilation
Hydrogen
Flow rate
Helium
Safety engineering
Air
Analytical models
Experiments

Cite this

@inproceedings{0fa39cbd7a2d4d86ab66fbe583c1a44e,
title = "Sustained Hydrogen Leak Concentration in Enclosure with One Vent",
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.",
author = "Vladimir Molkov and Volodymyr Shentsov and James Quintiere",
year = "2013",
month = "5",
day = "10",
doi = "10.3850/978-981-07-5936-0_14-03",
language = "English",
booktitle = "Unknown Host Publication",

}

Molkov, V, Shentsov, V & Quintiere, J 2013, Sustained Hydrogen Leak Concentration in Enclosure with One Vent. in Unknown Host Publication. Seventh International Seminar on Fire & Explosion Hazards (ISFEH7), 10/05/13. https://doi.org/10.3850/978-981-07-5936-0_14-03

Sustained Hydrogen Leak Concentration in Enclosure with One Vent. / Molkov, Vladimir; Shentsov, Volodymyr; Quintiere, James.

Unknown Host Publication. 2013.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

TY - GEN

T1 - Sustained Hydrogen Leak Concentration in Enclosure with One Vent

AU - Molkov, Vladimir

AU - Shentsov, Volodymyr

AU - Quintiere, James

PY - 2013/5/10

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N2 - 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.

AB - 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.

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