Quantitative Risk Assessment Of Key Equipment In Urban Gas Storage And Distribution Stations

The development of urban gas is conducive to optimizing the structure of urban energy utilization,optimizing air quality and achieving green development.Urban gas storage and distribution stations play an important role in gas distribution,pressure regulation and peak shaving,so they play a decisive role in the gas storage and distribution system.But at the same time,gas storage and distribution stations are also facing various threats:aging equipment and facilities;uneven level of operators;urban expansion makes urban storage and distribution stations originally located in the suburbs more and more close to densely populated areas;imperfect system and so on.Therefore,the risk assessment of urban gas storage and distribution stations is of great significance to ensure the safe operation of urban pipelines.Combining with relevant national and industrial standards of gas industry,this paper establishes safety checklist,preliminarily analyses the possible failure reasons of gas storage and distribution stations,divides gas storage and distribution stations into zones,and concretely analyses the failure forms,failure causes and possible consequences of the areas such as filter zone,pressure regulating zone and intake zone.Afterwards,the relationship between the failure causes of the stations is analyzed in detail by using the fault tree,and the bottom events are classified into five aspects:corrosion thinning,stress corrosion,external damage,brittle fracture and mechanical fatigue,so as to weigh all kinds of damage correction factors which need to be determined when calculating the failure probability,and then the failure probability which is more in line with the national conditions of our country is obtained.In this paper,the failure probability of all kinds of equipment in a gas station in Yunnan is calculated to be between 10^-4-10^-5.The scope of fire and explosion accidents under different leakage conditions and atmospheric conditions is analyzed.Combining with the specific situation of a storage and distribution station in Yunnan Province,the range of fire and explosion under the most vulnerable conditions is given.The impact of reputation on accident risk is considered.A risk matrix is established according to relevant criteria.The failure consequence of the risk matrix is judged by the total economic loss in terms of personnel,property and environment.Then,taking a gas station in Yunnan as an example,the risk value of key equipment in the station is calculated,and the risk grade is obtained.A set of risk assessment software is developed,which is applicable to a gas storage and distribution station in Yunnan as a whole and partly to other gas storage and distribution stations.The software can realize the three functions of failure probability,failure consequence calculation and risk classification of key equipment in the station.