Preslhy experiment series 4.4; material of the ground: concrete

Abstract: To identify and understand the ignition risks associated with situations unique to liquid hydrogen releases, where factors of cryogenic temperatures are significant. Ares of particular interest are: ignition potential at reduced temperature in the vapour phase; electrostatic charging in liquefied/multiphase mixtures; and energetic multiphase mixtures of hydrogen and oxygen. The key objective is to understand the impact of these particular circumstances on the likelihood of ignition, and to confirm the prioritisation of phenomena for further study within the project. Phenomena: Ignition above the pool under variable conditions (material of the ground, initial temperature). Abstract: To identify and understand the ignition risks associated with situations unique to liquid hydrogen releases, where factors of cryogenic temperatures are significant. Ares of particular interest are: ignition potential at reduced temperature in the vapour phase; electrostatic charging in liquefied/multiphase mixtures; and energetic multiphase mixtures of hydrogen and oxygen. The key objective is to understand the impact of these particular circumstances on the likelihood of ignition, and to confirm the prioritisation of phenomena for further study within the project. Phenomena: Ignition above the pool under variable conditions (material of the ground, initial temperature). TechnicalRemarks: The POOL-facility mainly consists of an insulated stainless-steel box with the dimensions 0.5 x 0.5 x 0.2 m³ that is filled up to half the height (0.1 m) with the respective substrate. The height of the LH2-pool that forms above the substrate can be determined using the weight of the complete facility, since it is positioned on a scale, but also 6 thermocouples that are located in different heights above the pool. Ignition point height varies from 8cm to 45cm.