Analysis On Explosion Characteristics And Technology Research Of Consequence Mitigation For LNG Station

LNG industry has developed rapidly because of its unique advantages and strong support and guidance from various countries.Therefore,it is very necessary to carry out the research on the accident consequence and the control of the disaster reduction.It is very important to ensure the normal operation of the system,ensure the safety of the staff and reduce the production cost.The paper depend on the of Ministry of public security's Key Laboratory Program,Study on the key problems of urban LNG station leakage disposal and accident prevention-control technology.Research contents are as follows:(1)The risk assessment of LNG fueling stationFirst of all,this paper chooes LNG fueling station as the main research object.By using the HAZOP analysis method as the risk identification process.The research focuses on the study of LNG station departure accident.According to the security measures for risk factors and the existing station system,the research puts forward suggestions and measures for risk prevention and control.Then,the fire & explosion index and level is obtained determine the degree of risk unit,according to the characteristics of the tank area.Compared the result with the index which is calculated after taking various remedial measures,suggestions and measures are put forward in three aspects of process control,material isolation and fire prevention measures.(2)Experiment and numerical simulation of explosion in small confined spaceAccording to the prototype of LNG regulator station,a small scale confined space explosion chamber is designed to carry out small-scale confined space oil and gas explosion experimentwhich replaces the natural gas with gasoline vapor.The FLACS software is used to verify the reliability of FLACS simulated confined space vapor cloud explosion,by establishing the equivalent model and simulating the explosion scenarios.This paper analyzes the influence of different gas concentration in confined space on the consequences of the explosion,and studies the effect of the length-width ratio and the size of the pressure drop on the explosion venting in confined space.(3)Numerical simulation of leakage and explosion of LNG stationAccording to the LNG station's actual size and different simulation scenarios,using FLACS to establish LNG station physical model and set the leakage and explosion parameters.Based on the simulation of different leakage and explosion conditions of LNG filling station,analyse the control effect of the two factors of the ventilation condition and the height of the cofferdam on the leakage and diffusion of LNG,study the influence of three factors,which are the natural gas concentration,the height of the vapor cloud and the space congestion degree of the aerated area,on the impact of the explosion.Finaly,the research provides theoretical support for the development of scientific suggestions for the LNG fueling station safety.(4)Development of LNG station risk analysis information systemThe risk analysis system of LNG filling station includes four modules as follows: basic information management,accident consequence analysis,risk index evaluation and system management.Its structural model of the system is composed of three levels: the basic database layer,the accident consequence analysis layer and the LNG risk assessment index.While conducting the risk analysis,the system links to the database to complete the bidirectional transmission of the data in the software and the data in the Access database.Based on the basic parameters of accident related input,it can calculate the consequences of various types of accidents,including the radius of the dangerous area and the severity of the accident,and calculate the risk of fire and explosion danger,the area of the exposed area and the property loss quantitatively.