Effect of burst disk parameters on the release of high-pressure hydrogen

•The effect of opening ratios of burst disk has been experimentally investigated.•The burst disk cannot fully open and forms a divergent nozzle.•The mean shock speed and shock overpressure inside/outside the tube reduce significantly.•The minimum initial pressure for spontaneous ignition increases significantly when χ = 2/3.•When χ ≤ 1/2, no ignition occurs even though initial pressure ratio is as high as 90. Hydrogen is regarded as an alternative energy carrier in the next decades and high-pressure hydrogen storage is treated as the best option. However, unexpected spontaneous ignition would occur during high-pressure hydrogen sudden release, which induces a severe safety issue. For improving the safety application of hydrogen, an experimental investigation has been conducted. Different diameter ring gaskets are employed to change the opening ratio χ. Pressure transducers and light sensors are used to record the pressure variation and possible light signals inside the tube, respectively. It is found that the burst disk is unable to fully open during high-pressure hydrogen release when χ