Research On The Determination Of External Safety Protection Distance Of Propylene Spherical Tank

In recent years,there have been several major chemical accidents in China,which have triggered strong social concerns.It was found that the causes of casualties and property losses in the surrounding areas were mostly issues including inadequate external safety protection of chemical facilities and surrounding areas,the small distance between the existing device and the neighboring residents,and unreasonable layout of dangerous facilities,etc.With the speeding up of urbanization in our country,the determination of external safety protection distance of chemical enterprises has become an urgent research topic to prevent major accidents from the source and reduce the severity of the accident.This paper summarizes the basic concept of external safety protection distance and the method and research progress of safe distance at home and abroad.Through comparative analysis,the consequence calculation method and the risk evaluation method studied were used for determining the external safety protection distance.The key factors affecting the distance of external safety protection were defined for the method of external safety protection distance.Starting from these key factors,this paper puts forward some suggestions to increase the equivalent safety protection distance.Taking the propylene spherical tank in the organic synthesis plant of Dalian Petrochemical Company as the research case and selecting the most readily formed vapor cloud explosion based on the result calculation method,we used software to predict the wind direction and the range of damage and adopted TNT method to calculate the scope of the accident when the domino effect occurs.We also used software to evaluate the individual risk curve and social risk curve of the propylene spheric al tank based on the risk calculation method.Both methods finally determine that the external safety protection distance of the propylene spherical tank area is not consistent with the national standard.We then combined the key factors of the evaluation of the two methods,and finally formulated some suggestions for reducing the external safety protection distance or increasing the equivalent distance of the propylene spherical tank area,thus providing reference for those chemical enterprises that cannot be moved immediately and whose external safety protection distances are inconsistent with the specification.