(491f) Development of Accident Scenarios and Consequence Analysis Using CFD Simulation for Hydrogen Refueling Stations

In recent years, hydrogen refueling stations have been constructed in Korea, including Yonsei university. Some of professors go to work by hydrogen fuel-cell vehicles. However, some people concern about safety of hydrogen. Therefore, hydrogen refueling station must be safe and secure because hydrogen is stored in large quantities under high pressure and it has a wide range of flammable limits. Furthermore, in the unlikely event of leakage, the damage needs to be kept on an allowable level. Safety of hydrogen is the first essential step toward practically using hydrogen as an efficient energy resource. For this reason, it is necessary to understand the behavior of hydrogen gas leak from the refueling stations.

In this study, we focused on the modeling of predicting the phenomena of hydrogen accidents. A number of accident scenarios were developed using FMEA. The scenarios are classified under small, medium and large release cases and divided by dispenser, compressor and storage tank. Numerical results on hydrogen concentration predictions were obtained in the real industrial environment, which is the hydrogen refueling station produced by GS-Caltex in Korea. As a result, the nine scenarios were simulated by using 3D CFD. Besides, these analyses were carried out in parallel with corresponding analyses for CNG.

The hydrogen clouds are farther from the ground level or buildings than in the case of the CNG due to buoyancy and high sonic speed at the release. In these cases, there was minimal difference between a small release from 40MPa hydrogen station and from 20MPa CNG station, however, a medium release from a hydrogen station was significantly more severe. On the other hand, in the case of a large release, it's indicated that CNG is more dangerous than hydrogen, because the reason is hydrogen diffuses promptly. Finally, in determining the safety distance, this study is useful for hydrogen station standard, code and regulation.