Vented hydrogen deflagrations in containers: Effect of congestion for homogeneous and inhomogeneous mixtures

TLDR

The study conducted 66 vented hydrogen deflagration tests in 20‑ft shipping containers, varying hydrogen concentration, vent area, venting device, ignition position, and congestion level, with 42 homogeneous and 24 inhomogeneous mixtures. The experiments show that internal congestion markedly raises the maximum reduced explosion pressure in vented deflagrations, underscoring the need to include congestion effects in explosion‑protection standards and guidelines. The project was funded by the Fuel Cells and Hydrogen Joint Undertaking (FCH JU).

Abstract

This paper summarises the results from 66 vented hydrogen deflagration experiments performed in 20-foot shipping containers: 42 tests with initially homogeneous and quiescent mixtures, and 24 tests with inhomogeneous mixtures. Other parameters investigated include hydrogen concentration, vent area, type of venting device, ignition position, and the level and type of congestion inside the container. The results confirm that internal congestion can increase the maximum reduced explosion pressure in vented deflagrations significantly, compared to vented deflagrations in empty enclosures. As such, it is important to incorporate the effect of congestion in the theoretical and/or empirical correlations recommended in standards and guidelines for explosion protection. The work reported here is a deliverable from work package 2 (WP2) in the project “Improving hydrogen safety for energy applications through pre-normative research on vented deflagrations” (HySEA). The project received funding from the Fuel Cells and Hydrogen Joint Undertaking (FCH JU).