Typical Scenario Construction And Emergency Decision-making Of Hazardous Gas Leakage Accidents

In recent years,the types and quantities of hazardous chemicals have been rapidly improved and widely used.As an important industrial raw material,liquid ammonia is widely used in denitration systems of thermal power plants and refrigerants in factories.Ammonia leakage accidents occur frequently,resulting in serious personnel.Casualties,property damage and environmental damage have received widespread public attention.Therefore,the research on the cause factor,leakage diffusion law and emergency decision-making of ammonia leakage accident can prevent the occurrence of accidents,effectively predict the ammonia leakage diffusion process,and provide valuable data support for on-site accident rescue and emergency evacuation.Provide important technical guarantees for the preparation of emergency plans and emergency command.The research progress and conclusions are summarized as follows:There are many causes of ammonia leakage accidents.In order to analyze the causal factors that may cause accidents and rank their contribution,a dynamic fuzzy Bayesian model of ammonia leakage accident is established.The model is divided into two parts.It is the use of ambiguity to fuzzify the basic events that are difficult to obtain by human factors and failure probability,and finally defuzzification to obtain a more reasonable basic event failure probability,so that the calculation results are more scientific.Second,the dynamic Bayesian ammonia is adopted.Dynamic risk analysis of leakage accidents.The study provided strong support for the prevention of accidents in ammonia-related enterprises.After the ammonia leakage accident,the difference in the type and effectiveness of the measures will lead to different accident development.In order to grasp the possible development path of the accident,based on the theory of “scenario-response”,based on the “time window” theory Scenario construction of hazardous chemical spill accidents,combined with relevant accident experience at home and abroad,establish a model for constructing ammonia leakage accidents and explore the evolution law of accidents.Scenario construction can not only study the evolution process and regularity of emergencies,but also provide a scientific basis for accident prevention,reducing the degree of accident impact,preparing emergency response plans and improving emergency response capabilities.The diffusion process of ammonia is complicated.Although the field test can effectively record the real data of the diffusion movement,the cost is huge and the experimental conditions cannot be copied.Although the empirical model can roughly approximate the distance of ammonia leakage diffusion,it is only applicable to the conditions of obstacle-free materials,and the calculation accuracy is not high,and the accuracy of the results cannot be guaranteed.In order to solve the above problems,the computational fluid dynamics method was used to study the diffusion law of ammonia under different influencing factors(leakage speed,wind speed,wind direction,leak height and leak size),and design orthogonal experiments to explore five kinds.The sensitivity of the factors to the ammonia leakage accident shows that the order of sensitivity from high to low is the leakage speed,the size of the leak,the wind speed,the location of the leak and the direction of the wind.The top three of the sensitivity rankings were selected to study the case scenario to determine the distribution of ammonia concentration in the time and space under the complex terrain of the instance scene.The Patnfinder software was used to explore the time required for people to escape under different evacuation scenarios,according to the distribution of ammonia concentration and The choice of escape route calculates the probability of human poisoning death in different scenes and different regions,and establishes the emergency planning area,the “shortest escape route” and the emergency rescue system in each scenario after the ammonia leakage accident.Finally,a systematic technical system for prevention,control and emergency of ammonia leakage accidents will be formed to prevent the occurrence of ammonia leakage accidents,reduce the consequences of accidents,take correct emergency decisions,safeguard the lives and property of personnel,and It is of great significance to promote the normal operation and safe production of enterprises.