Research Of Environmental Risk Assessment Of Sudden Typical Accident For Storage Tanks Of Dangerous Chemicals

In recent years, China’s chemical industry park construction has developed rapidly. In these industry park there are always large-scale storage tank areas. A large number of toxic, hazardous, flammable, explosive and dangerous chemicals are stored in these tank areas, which are most major hazard sources. According to some statistics, the frequency of such dangerous chemicals leakage accident in pollution accident is higher.In order to facilitate the storage of dangerous chemical substances, chemical plant usually store these chemical substances in the form of liquid, high pressure, low temperature in the storage tanks or other high-pressure or pressure vessel. Due to harsh storage conditions, accompanied by a variety of dangerous operation caused by human errors, hazardous chemical storage tanks become a significant source of risk. When the storage container leaks, leakage of toxic and hazardous substances into the atmosphere can cause personal injury and environmental pollution, and also may cause fire or explosion accidents. Risk assessment study of these suddenly typical accident of chemicals has practically significance. According to recent references, liquid ammonia and liquid chlorine storage tank leak accidents have the highest frequency. This thesis takes the Dalian Songmu Island ammonia synthesis project and relocation and transformation project of Dalian Chemical Group Co., Ltd.(first stage) as example, assess the environmental risk of the leaks of ammonia, liquid chlorine storage tank and providing a reference for risk prevention.At the same time, in previous literatures and similar accident risk assessment reports, the authors did not carry out a detailed study for the selection of the model of the accidents and ignored the effect of relevant parameters during the risk assessment of dangerous goods. To solve this problem, this thesis selecte two meteorological conditions, the D stable degree3.5m/s wind speed and the F stable degree wind speed1.5m/s; two different leak locations, tanks and pipelines; different leak heights, tank top and different liquid levels; different sizes of the leak sources of the leak,5mm holes rupture,50mm big hole rupture,20%of the pipe rupture and100%pipeline rupture. The consequences of different leak modes are qualitative analysis and quantitative calculation. This work also compare the different leak states, leak locations, leak conditions under predictions of liquid ammonia and liquid chlorine storage tank leaks, summarize and qualitative analyze the combined predicted results of different conditions, at the same time, get the risk value of different accident conditions through product of farthest distance of accident affecting with accident probability value. It is demonstrated that risk value is the highest when selecting20%pipeline rupture. This work provide a reference parameter selection of sudden and typical leak accidents.