Research On Leakage And Diffusion Law And Control Of Liquid Chlorine In Road Transportation

As a common hazardous chemical,liquid chlorine needs special attention and protection during its life cycle because of its high toxicity,strong oxidation and easy flash evaporation.Especially due to the influence of uncertain conditions in road transportation,it is difficult to prevent and control the consequences of leakage and diffusion accidents of liquid chlorine tank trucks.The research on the leakage and diffusion law of liquid chlorine tanker is the basis of the prevention and control of leakage and diffusion accidents of liquid chlorine.In view of the complexity of the leakage and diffusion process of liquid chlorine tanker and the seriousness of the accident consequences,this paper applies the professional knowledge and theory of safety science and technology,computer science,fluid mechanics and other related disciplines,and adopting the research method of statistical analysis,theoretical analysis and numerical calculation to study the leakage and diffusion law of liquid and gas phase of liquid chlorine tanker under uncertain conditions.Combined with the simulation results,aiming at the most unfavorable leakage and diffusion conditions of ramp sections,a water mist inhibition chlorine diffusion model was established,and the key parameters of water mist inhibition chlorine diffusion were determined.The main work is as follows:(1)on the basis of theoretical analysis of the basic physical and chemical properties of liquid chlorine and its leakage and diffusion process,systematically study the leakage and diffusion model,and determine different leakage modes,occurrence mechanisms and conditions of liquid chlorine tanker;Through the analysis of the influencing factors of chlorine gas diffusion and the investigation results of the existing leakage diffusion treatment methods of liquid chlorine tank cars,it is determined that water spraying is the method to restrain chlorine gas diffusion.(2)based on the theoretical model of leakage and diffusion of liquid chlorine tanker,the numerical calculation model of leakage and diffusion of liquid chlorine tanker under uncertain conditions is established.The influence of different wind direction,wind speed,leakage aperture and road conditions on the leakage and diffusion of liquid chlorine tanker were studied.The most unfavorable conditions of leakage and diffusion of liquid chlorine tanker are determined as follows: liquid space leakage,and the wind speed is 4 m/s;Gas phase space leakage under static wind conditions;At the same wind speed,there will be a 10 mm leakage.The leakage point is located at the ramp part.(3)combined with the numerical simulation results of the most unfavorable conditions,a water mist control method based on DPM discrete-phase model is proposed.According to the simulation analysis results of water spray to suppress the leakage and diffusion of liquid chlorine tanker,the law of water spray to suppress the diffusion of gas cloud is obtained.In order to obtain a better effect of water mist on inhibiting chlorine diffusion,the influence of key parameters such as different types,numbers and positions of spray sources on the inhibition effect was studied.The results show that different types of spray sources can have a good inhibition effect,but different modes of action,the number of spray sources and the arrangement position of spray sources have a great influence on the inhibition effect of water spray.Results the influence law of the key influencing factors of the leakage and diffusion of liquid chlorine tanker was further improved,which provided reference for the related theoretical research in the field of safety.The numerical model and analysis conclusion of restraining chlorine diffusion by water mist can provide reference for the actual emergency treatment methods.