This research consists of two parts. The first part is to evaluate the fire risk due to the hydrogen leakage or diffusion from the hydrogen storage system. The second part is to verify compliance with the fuel leakage limit of a hydrogen fuel cell vehicle in the event of collision. To evaluate the fire risk of the fuel storage and delivery system in a hydrogen fuel-cell vehicle, sensors were installed at locations where leaking hydrogen was likely to be trapped. These sensors were installed in the engine compartment, the occupant compartment and in the rear of a vehicle. The fuel processing system and fuel-cell stacks were located in the engine compartment. The behavior of leaking hydrogen was investigated when a vehicle was at rest, moving, and after shut-down caused by hydrogen leakage. In some area the concentration reached up to 4%. The optimization of number of sensors and locations was also investigated for effective detection.
To assess the vehicle fuel system integrity and electrical safety in the event of a crash, three different crashes were carried out. One full frontal impact test at the speed of 48 km/h, one side impact test at the speed of 50 km/h with a deformable moving barrier and one rear impact test at the speed of 48 km/h with a moving barrier were conducted. The hydrogen fuel storage systems were filled to 90 % of the nominal working pressure with helium gas at each test. Even though the hydrogen fuel cell vehicle subject to tests was equipped with crash sensors that enabled the high pressure valve of the storage container to be closed automatically in the event of a crash, all crash sensors were removed to simulate severe test conditions in these experiments. After each crash, the amounts of hydrogen leakages were measured, and electrical safety were examined.
In this experiment 8 research institutes, including the Korea Automobile Testing and Research Institute, Hyundai Motor Company, took part. This project was supported by the Ministry of Land, Transportation and Maritime Affairs of the Republic of Korea.