(151b) Very-Lean Hydrogen and Worst-Case Ammonia Vented Deflagration Testing and Modeling

Accurately modeling explosion hazards associated with new and existing hydrogen and ammonia distribution/transportation networks is a key component to growing these networks safely. This work discusses results obtained through large scale testing performed as part of BakerRisk’s Internal Research program and how the results compare to methods typically used by industry to quantify the hazards associated with the handling of hydrogen and ammonia.

BakerRisk performed a field-scale (>13,600 cubic ft) test program as part of an internal research effort to evaluate the severity of vented deflagrations from very-lean hydrogen-air mixtures (10-16 H₂%), and worst-case ammonia-air mixtures (23% NH₃). Four test series were completed as part of the program. The results of hydrogen and ammonia tests were compared to identical tests using methane and propane. Methane and propane are representative of low and medium reactivity fuels, respectively, in the Baker-Strehlow-Tang (BST) vapor cloud explosion (VCE) blast load prediction methodology. The test data are compared with calculations based on standard methods commonly applied to predict vented deflagration blast loads. Specifically, the results of these tests are compared to those calculated using the National Fire Protection Association Standard on Explosion Protection by Deflagration Venting (NFPA 68) and the FLACS computational fluid dynamics (CFD) code.