Title: Explosion Protection at the German Metrology Institute PTB
Time: 14:00 to 16:00, Monday, April.15, 2024
Place: F310, School of Mechanical Engineering
Host: QI Fei, Professor (Institute of Aerospace Propulsion)

Biography
Dr. Arnas Lucassen, Head of Working group 3.72 Explosion Processes Under Non-Atmospheric Conditions, PTB Physikalisch-Technische Bundesanstalt Braunschweig und Berlin.

Abstract
The lower explosion point (LEP) is an important safety characteristic parameter in explosion protection. In the transition to a zero-carbon-dioxide emission society, the addition of hydrogen to the gas grid system is one crucial step to distribute the hydrogen. Presently the hydrogen content is limited to 20 %v, but the goal is to increase this amount further. The common safety characteristics of hydrogen-methane-air mixtures were investigated in recent years, in terms of laminar burning velocity, flammability limits, and other essential parameters, confirming that methane dominates the combustion regime up to about 50 %v of hydrogen. However, no studies have addressed the analysis of the deflagration to detonation transition (DDT) and, more specifically, the effect of the hydrogen addition on the run-up distance and the cell size of the methane-air mixtures. The investigations in this work obtained experimental data aiming at defining run-up distances, and hydrogen/methane fractions for safety measures and calculations of possible DDTs. The other focus of this work is to determine the uncertainties of experimental data measured by Electron ionization molecular-beam mass spectrometry (EI-MBMS).