Study On Determination Method And Improvement Strategy Of Safety Protection Distance Of Urban Refinery

China's economy has been at a stage of rapid growth since the reform and opening up.The transformation of industrial structure and a large number of migrant workers dedicated in urban construction have accelerated the process of urbanization.The scope of urban land has been expanding from the center to the outside.As a result,petrochemical enterprises originally far away from the suburbs of the city have begun to merge with the city.The open space around refineries has been developed into residential,commercial and living areas.A large number of buildings and facilities around the refineries led to the emergence of urban refineries.The contradiction between urban refineries and the surrounding residents is deepening thus it has forced the refineries facing the problem that the refineries are too close to the surrounding sensitive areas,and there is not enough external safety protection distance.In order to solve this problem and realize the isolation and harmonious coexistence between urban refineries and the surrounding residents,this thesis based on the characteristics of urban refineries and previous studies to determine the appropriate definition of external safety protection distance.Compared with the existing methods for the determination of the safety protection distance,this study analyzed the advantages and disadvantages of various methods,and then formulated the method to determine the safety protection distance of urban refineries.The proposed method combined with the specific requirements of protection distance by the Chinese authority,and then used quantitative risk assessment to calculate the overall risk of urban refineries and to correct the simulation results of the consequences of major accidents.The results impact of each parameter used in the quantitative risk assessment was analyzed,and the key influencing parameters including population distribution,meteorological conditions,failure probability,ignition source,and ignition probability were determined.To overcome the subjectivity issues in the determination of parameters and to standardize the calculation process of external safety protection distance,the corresponding determination principles were formulated for the key influencing parametersIn this thesis,by considering the impact of the safety improvement measures such as safety technology measures and safety management level of the refinery on the failure probability,the fuzzy comprehensive evaluation method was used to correct the failure probability,so as to correct and optimize the external safety protection distance.Finally,a city refinery was taken as the case study to demonstrate the proposed method,which verified the effectiveness of the method and provided a reference for the determination of the safety distance of urban refineries.