Research on natural gas leakage and diffusion characteristics in enclosed building layout

Abstract

There are many people in urban construction areas, and natural gas leakage can potentially cause serious accident consequences. Predicting the consequences of gas dispersion is important to react rapidly and adequately in the event of an incident. Currently, computational fluid dynamics (CFD) models are an important tool to predict gas dispersion. However, in most cases, considering computational cost, the building layouts is ignored, so the flow field influence near the building area cannot be considered. In this research process, a realizable k-ε turbulence model is used to simulate the natural gas leakage process in a typical building layout (enclosed building layout), while focusing on wind speed and the leakage position. The validity of realizable k-ε turbulence model is verified by experimental data. The results show that under conditions of high wind speed (wind speed≥ 6 m/s), the reverse vortex formed by the shear flow of wind can cause the natural gas cloud to sink. When the leak hole is located in the influence area of the turbulent vortex, it easily induces R-H instability. When combined with the stronger K-H instability at high wind speeds, natural gas clouds may accumulate. This then leads to serious leakage accidents, knowledge of which may be the key component of emergency management during an accidental natural gas leakage. The research results can guide the building layout plan and gas pipeline construction to prevent accidents.