(81c) Very-Lean Hydrogen Vapor Cloud Explosion Testing

Hydrogen is a key energy carrier for modern society. An increased focus on “net-zero” greenhouse gas emissions, specifically carbon dioxide and methane, has resulted in a global push for lower carbon energy vectors, including pure hydrogen. Accurately modeling explosion hazards associated with new and existing hydrogen distribution and transportation networks is a key component to growing these networks safely.

To contribute to the global knowledge base, BakerRisk has performed a series of lean hydrogen-air vapor cloud explosion (VCE) tests as part of an internal research effort. The goal of these tests was to better understand the explosion hazards associated with very lean (12-14 H₂%), unconfined, hydrogen-air mixtures. These tests were performed in a rig similar to that used previously by BakerRisk to tests lean hydrogen VCEs (down to 16%H₂). BakerRisk measured flame speeds and blast loads using high speed video and an array of dynamic pressure transducers. This paper discusses the test setup used and test results obtained. A comparison is provided between test results and computational fluid dynamics (CFD) modeling using FLACS, including the FLACS dP/dX criterion for the onset of a deflagration to detonation transition (DDT). A discussion regarding the application of these test results to facility siting studies is also provided.