서강대학교

초록/요약

Gas safety issue related to fuel gas facility is attracting many researchers. Natural gas is remarkable fuel gas due to its characteristics. However, its release in facility leads to critical accidents such as fires and explosions etc. Although it has high possibilities to occur accidents by fuel gas release at indoor space, most of previous researches mainly focused on the release model itself or accidents in open field space. Meanwhile, combined cycle power plant is one of the most typical natural gas facilities. In recent years, the technology of constructing combined cycle power plant in underground space has been examined. Because underground space is almost enclosure, the safety issues for the underground power plant must be considered prior to construction. In this thesis, numerical studies were conducted in order to propose the methodologies for risk assessment. First of all, hydrogen release was considered, followed by natural gas release. The enclosure effects in flow characteristics of release flow were investigated. Recirculation and stratification were able to observe because of the geometric effect. In addition, flammable region formed by gas release was estimated for each study. Flammable region enlarged as leakage time elapsed. Furthermore, mathematical modeling of flammable region for natural gas release was performed. From the aspect ratio of flammable region and ellipsoid equation, oval-shape model was proposed in this thesis.