Effects of hydrogen jet fires on the erosion of tunnel road materials and lining materials

This HSE test programme investigated erosive effects of an ignited high pressure hydrogen jet impinging onto concrete and tarmac structural materials. The chosen test conditions mimicked the scenario where a high-pressure release (700bar) occurs from a fuel cell hydrogen (FCH) car as a result of activation of the thermal pressure relief device (TPRD) on the fuel tank. Two nozzle sizes were used for the releases; the first had a diameter of 2.1mm (mimicking existing TPRD) and the second had a diameter of 0.57mm (mimicking a proposed alternative TPRD diameter. The reduced diameter is suggested as a strategy to reduce release hazard safety distances).