Abstract: The hydrogen leakage and ignition test bench of fuel cell vehicle（FCV） hydrogen storage system was built in this paper, and then high-pressure hydrogen leakage ignition experiments were carried out. The risk parameters of hydrogen jet flame morphology, flame length, and typical position temperature, thermal radiation flux were collected. In addition the numerical simulation of hydrogen leakage leading to explosion in the FCV passenger compartment was studied. As the result shows, The leakage time of 0.4 L/0.84 MPa high-pressure hydrogen gas through a circular hole with a diameter of 6 mm was only 80 ms. The hydrogen jet flame length was 1.4 m horizontally burning continuously only for 0.3 second. The highest hydrogen combustion intensity was at a distance of about 1.0 m from the leakage port, and the maximum thermal radiation flux collected was 0.27 kW/m2. The numerical simulation results show that after hydrogen leaking and catching fire in the passenger compartment, the entire cabin was ignited within only 28 ms. The highest temperature in the cabin exceeded to over 2 000 ℃ and the maximum pressure exceeded to over 0.5 MPa. The risk of hydrogen leakage of vehicle hydrogen storage system leading to combustion and explosion is extremely high which seriously endangering the safety of passengers. FCV safety design should be strengthened to avoid such accidents.

Key words: FCV hydrogen storage system, hydrogen leakage, combustion risk, numerical simulation