Research On Model Constructionof Hazardous Gas Diffusionafter Leakage In Road Transportation And Emergency Management

Hazardous materials’ demand which is to be raw material or production processing accessories is growing year by yearwith the high-speed development of modern industry, so transportation pressure also increases year by year.Many hazardous gases are toxic, flammable or explosive which will cause poisoning,fire, explosion and other accidents once the leakage occurred in the road transportation, and then cause serious damage to the lives, property and environment of the surrounding. Tank cars with hazardous gas are like moving hazardswith great risk.Therefore, it has great significance to calculate concentrationdistributionof the dangerous gas and diffusion area, and divide the dangerous areas fast、effectively and intuitively after the leakage during transportation.First of all, this paper researched the occurrence and development, the mechanism of leakage and the leakage source form of hazardous gas leakage accidents in road transportation. The leakage can be divided into instantaneous leakage and continuous leakage according to different leakage source forms and characteristics.Take road transportation of liquid chlorinefor example, establish instantaneous leakage and continuous leakage source model respectively according toits dynamic process, the material characteristicsandleakage mechanism,etc.Secondly, after analyzing the influence factors of hazardous gas diffusion, combining leakage and diffusion characteristics of hazardous gas in road transportation,and introduce dynamic leakage intensity, tank car moving direction and speed, and then three diffusion models that are suitable for hazardous gas in road transportation have been set up: fixed point’s instantaneous leakage diffusion model, fixed point’s continuous leakage diffusion model and moving point’s continuous leakage diffusion model.And then, with road transportation of liquid chlorine being the research object,simulate three typical scene of liquid chlorine leakage with MATLAB software, and then calculate chlorine concentration distribution and diffusion areain the form of 3-d visualization. After that, four dangerous areas are divided according to the severity into immediate death area, severe area, moderate area and mild area.At the same time, diffusion results of three scenariosalso verified the rationality of the leakage source model and diffusion model.Then transport leakage diffusion simulation was introduced into the emergency response to build a series of emergency response procedures which includes the receiving alarm,transportationleakage diffusion simulation, warning information release, emergency response action and site restoration.The emergency response can provide a scientific basis for early warning and rescueof leakage accidents.Finally, combined with above analysis and research, took a domestic transport enterprise transporting liquid chlorinefor example, used the leakage model and diffusion model built in this paper, and then simulated in anroad accident scene assumed. Calculated the dangerous gas total influence region and evacuation region, and put forward the corresponding emergency response measures. Case studies show that the research results can be used to provide technical support for emergency response and rescue work of relevant departments.Above of all, in this dissertation,the leakage source model and diffusion model have been builtconsidering leakage and diffusion characteristics of hazardous gas in road transportation,and three typical leakage accident scenarios have been simulatedin MATLABsoftware. Finally, the leakage diffusion modelswere introduced toemergency management to establish a set of leakage accident emergency responseprocedures.Research results of this dissertation can providetheoretical support for early warning, emergency rescue and risk assessment of leakage accidents in transportation and build the foundation of hazardous gas road transportation safety guarantee system.