Consequence Assessment And Emergency Response Research Of Hazardous Gas Road Transport Leakage Accidents

Road transportation has become one of the main ways of hazardous chemicals transportation because of its convenient,timely and economical characteristics.Gas tankers account for a large proportion in the transportation of hazardous chemicals.Once the gaseous hazardous chemicals(hereinafter referred to as "hazardous gases")leaks,it is easy to spread to the surrounding areas.If the possible evolution pattern of secondary disasters cannot be effectively predicted and judged,and the consequences of the accident and its influence scope cannot be determined scientifically,it will not be able to provide an accurate decision-making basis for subsequent emergency response,thereby affecting the effect of emergency rescue.Therefore,a comprehensive and systematic assessment of the consequences of the hazardous gas leakage accident,an accurate prediction of the scope of the impact of the accident,and the formulation of scientific and reasonable emergency treatment methods,is conducive to reduce the casualties caused by the hazardous gas road transport leakage accident,and improve the efficiency of emergency rescue.To this end,this paper studies from the following four aspects:(1)The evolution mode of dangerous gas road transport leakage accident is analyzed.According to the theory of accidental release of energy,the dangerous characteristics of the gas are identified as Class I hazard sources,and the Class II hazard sources are identified from the four aspects of people,vehicles,roads and management;There are four evolution modes of accident: poisoning,jet fire,vapor cloud explosion,and expanding vapor explosion of boiling liquid.According to the causes and influencing factors of leakage,the Gaussian plume and puff diffusion model of instantaneous leakage of dangerous gas,continuous leakage are analyzed.(2)Evaluated the consequences of a hazardous gas road transport spill accident.Based on the toxic load model,point source model,overpressure model and fireball model,the basis for the division of severe,moderate and mild danger zones for various accident types is determined;the AHP is used to establish an accident consequence assessment model,which divides the accident consequences into different categories.There are three grades of A,B,and C,and the grading indicators of each grade are quantified.(3)The emergency treatment method for the leakage accident of dangerous gas road transportation is determined.According to the situation of dangerous gas leakage accident,the emergency response is divided into four levels: I(especially serious),II(major),III(larger)and IV(general).Isolation and evacuation,on-site disposal are three parts,and specific countermeasures are put forward;and Floyd algorithm is used to analyze the best refuge and evacuation route for emergency evacuation,which provides decision-making basis for emergency disposal work and improves emergency disposal efficiency.(4)The feasibility of the accident consequence assessment model and emergency response method is verified.Taking an ammonia gas transportation leakage accident as an example,according to the dangerous characteristics of ammonia,the dangerous area of ammonia gas road transportation leakage accident was simulated by MATLAB software,and the accident consequence was C level and the accident response level was At the same time,the comprehensive emergency evacuation area of the accident was obtained,and the evacuation route from each residential gathering point to the emergency shelter was determined,and the emergency treatment methods such as on-site first aid,leakage disposal,and on-site decontamination of ammonia leakage accident were studied.Based on the multiple evolution models of dangerous gas road transport leakage accidents,this paper determines the dangerous areas of poisoning,fire and explosion accidents,establishes a comprehensive accident consequence assessment model,and uses the analytic hierarchy process to classify the accident consequences.The classification results can predict the consequences of leakage accidents in advance,classify emergency response levels,determine the scope and route of emergency evacuation,and provide decision-making basis for the orderly development of emergency response.has important practical significance.