Risk Analysis Of Ammonia Leakage And Explosion In Refrigeration Enterprise

This paper explores the risk of ammonia leakage and explosion in refrigeration enterprises,and systematically sorts out the system risks existing in the production and operation of ammonia refrigeration enterprises.First,based on the system dynamics theory,the risk coupling relationship diagram is drawn by using Vensim software.The results show that with the increase of the number of coupling risk factors in the system,the probability of ammonia leakage and explosion accident in ammonia refrigeration enterprises decreases,and the consequential loss of the whole system increases once the accident occurs.By analyzing the causal logic relationship of risk coupling,it lays a foundation for the basic event selection and model logic analysis of the later establishment of fault tree-dynamic Bayesian model.Establish liquid ammonia leakage explosion dynamic bayesian network model,the fault tree of step is introduced the establishment of dynamic bayesian networks and reasoning process,using the method of fault tree analysis logic to find out the cause of the ammonia refrigeration system,the fault tree analysis top event track of liquid ammonia leakage explosion,determine liquid ammonia leakage explosion impact basic event of the bottom of society,Dynamic Bayesian network model was used to analyze the occurrence probability of each event.The conditional probability table(CPT)of each intermediate event is calculated by introducing the probability model of fuzzy mathematics theory.The state transition probability of liquid ammonia leakage and explosion accident node was calculated,that is,the probability of state change of the same node between two adjacent time pieces.The dynamic Bayesian inference algorithm in Genie software was used to update the posterior probability of the whole dynamic Bayesian network model finally.At the same time,the prediction of using dynamic bayesian network,through a cycle of liquid ammonia refrigeration system to monitor the operation,can be obtained within the system of the small part of the damage of the whole ammonia system leak explosion probability value and the effect of using GENIE software built-in algorithm,realize forecast next time slice top event occurrence probability,The influence degree of each node on the occurrence of liquid ammonia leakage and explosion accident at the top event was ranked to provide important guidance for the daily safety supervision of ammonia-related refrigeration enterprises.Finally,taking the actual ammonia storage capacity of Maanshan plant as an example,the steam cloud explosion(UVCE)damage model was used to calculate the TNT equivalent of the total ammonia storage capacity of the plant,the high-pressure ammonia reservoir area,the auxiliary liquid reservoir area and the low-pressure circulating liquid storage tank area,and the Risk System software was used to get the simulation results of the damage range of the steam cloud explosion.It provides the damage range of liquid ammonia leakage and explosion prediction for Maanshan factory,and provides a strong basis for the specific prevention and control measures taken in the later stage.