Publications

Analysis of a Full Scale Blowdown Due to a Mechanical Failure of a Pressure Relief Device in a Natural Gas Vehicle Maintenance Facility

Blaylock, Myra L.; Bozinoski, Radoslav B.; Ekoto, Isaac W.

A computational fluid dynamics (CFD) analysis of a natural gas vehicle experie ncing a mechanical failure of a pressure relief device on a full CNG cylinder was completed to determine the resulting amount and location of flammable gas. The resulting overpressure if it were to ignite was also calculated. This study completes what is d iscussed in Ekoto et al. [1] which covers other related leak scenarios. We are not determining whether or not this is a credible release, rather just showing the result of a possible worst case scenario. The Sandia National Laboratories computational tool Netflow was used to calculate the leak velocity and temperature. The in - house CFD code Fuego was used to determine the flow of the leak into the maintenance garage. A maximum flammable mass of 35 kg collected along the roof of the garage. This would result in an overpressure that could do considerable damage if it were to ignite at the time of this maximum volume. It is up to the code committees to decide whet her this would be a credible leak, but if it were, there should be preventions to keep the flammable mass from igniting. Keywords: Natural Gas Vehicle Maintenance Facility, Pressure Relief Device Failure, CFD