Risk Quantitative Calculation and ALOHA Simulation on the Leakage Accident of Natural Gas Power Plant

In order to study gas leakage accident risk in Natural Gas Power Generation Co., Ltd. and its impact on the surrounding residents, we analysis the accident scenes of natural gas power plant and accident scenes which may occur in the key hazardous areas. By taking the pipeline leakage accident in the last branch lines station as example, the diffusion statuses were simulated by using ALOHA after the natural gas leak. The frequency of pipeline leakage accident and the consequences in the power plant were analyzed. Then individual risk and social risk were obtained. The results show that social risk of the plant is related to the population distribution near natural gas pipelines and the factors of death probability. Assuming three kinds of leak conditions that leakage apertures are respectively 100 mm, 200 mm and 1200 mm, the individual risk and social risk are beyond the acceptable range. When pipeline leakage aperture is 100 mm, rescue and evacuation shall be promptly carried out in the power plant and the leakage accident has no effect on the town. When pipeline leakage aperture is 200 mm, people should immediately control the leak and make the explosion-proof measures from 55m to 92m of the power plant downwind which is in the range of natural gas explosion limits. When pipeline leakage aperture is 1200 mm, emergency evacuation measures should be taken and prevent accidents expanding in most of the town which is in the range of natural gas explosion limits. The results of the quantitative risk calculations and ALOHA simulations provide bases and decisions for the pipelines plan, construction of natural gas power plant and the spatial location of the town.