Fuel-scale Tunnel Experiments for Fuel Cell Hydrogen Vehicles: Gas Dispersion

In the framework of the HYTUNNEL-CS European project sponsored by FCH-JU, a set of preliminary tests were conducted in a real tunnel in France. These tests are devoted to safety of hydrogen-fueled vehicles having a compressed gas storage and Temperature Pressure Release Device (TPRD). The goal of the study is to develop recommendations for Regulations, Codes and Standards (RCS) for inherently safer use of hydrogen vehicles in enclosed transportation systems. In these preliminary tests, the helium gas has been employed instead of hydrogen. Upward and downward gas releases following by TPRD activation, has been considered. The experimental data describing local behavior (close to jet or below the chassis) as well as global behavior at the tunnel scale are obtained. These experimental data are systematically compared to existing engineering correlations. The results will be used for benchmarking studies using CFD codes. The hydrogen pressure range in these preliminary tests has been lowered down to 20MPa in order to verify the capability of various large-scale measurement techniques before scaling up to 70MPa, the subject of the second campaign.