Hydrogen Blowdown Release Experiments at Different Temperatures in the Discha-facility

In this work experiments on horizontal hydrogen jet releases from a 2.815 dm³ volume tank to the ambience are described. For the main experimental series, tank, valve and release line were cooled down to a temperature of approx. 80 K in a bath of liquid nitrogen. As a reference, similar experiments were also performed with the uncooled tank at ambient temperature. The releases were carried out through four nozzles with different circular orifice diameters from 0.5 to 4 mm and started from initial tank pressures from 0.5 to 20 MPa (rel.). During the releases pressures and temperatures inside the vessel as well as inside the release line were measured. Outside the nozzle further temperature and hydrogen concentration measurements were performed along and besides the jet axis. The electrostatic field builtup in the jet was monitored using two field meters in different distances from the release nozzle and optical observation via photo and video-cameras was performed for the visualization of the H2-jet via the BOS-method. The experiments were performed in the frame of the EU-funded project PRESHLY, in which several tests of this program were selected for a comparative computational study, the results of which will also be presented at this conference. So, on the one hand the paper gives a comprehensive description of the facility, on the other hands it also describes the experimental procedure and the main findings.