The Research And Application Of Control Measures In The Process Of Ammonia Refrigeration Station Leakage Accident Based On Numerical Simulation

Ammonia leakage accidents occurred frequently at ammonia refrigeration station,which poses a grave threat to the atmosphere of people’s peace and happiness and limits the benefit of enterprise,how to prevent ammonia-related enterprises accidents effectively has become an urgent technological difficult problem in the field of safety production.Identifying potential factors in advance,understanding the existing way and triggering conditions of it,understanding the possibility it cause accidents,then analysis the law,damaging range and consequence of leakage process,it has great positive effect to control the occurrence of accidents throughout the whole process and reduce the damage caused by these ammonia leakage accidents.The article first theoretically analyzes the physicochemical property,harmfulness,the leaking and diffusion process of ammonia,then summary and classify the risk factors of ammonia-related enterprises,identify the weight of these risk factors using improved hierarchical analysis,provide theoretical base for making prevention measures.Under this premise,taking mengniu dairy’s refrigeration station as research object,simulating ammonia’s different leakage states under different conditions 1# refrigeration station affiliated room using Fluent 18.0,then give some practical suggestions on how to make emergency measures after ammonia leakage through comparing density map,velocity vector graph and the time-dependent concentration curves.First a variety of safety evaluation methods were introduced.For example,Security checklist method,Chemical safety assessment method,Probability risk assessment method,Fuzzy comprehensive evaluation method,Level-gray prediction method and so on,which provided theoretical guarantee for the following case analysis.The main achievements on the research and of control measures in the process of ammonia refrigeration station leakage accident are as follows:(1)The harm of ammonia include toxicity,combustible and explosive,once the leakage accident happens the consequence will be disastrous.Analysing ammonia refrigeration station accidents,summarize and classify from four aspects: human,objects,environment,manage,deep excavation the causes of accidents.(2)Infiltrate the accident tree into the analytic hierarchy process,build analytic hierarchy process model according to accident tree,calculate the weight of each factor using yaahp10.5 get the result that employee’s emergency ability,maintainer’s repair schedule,whether the management system is consummate,accident handing occupy important place in causes.(3)Inorder to find out ammonia leakage law,I build calculation model by combining Fluent software and the real situation of refrigeration station,then build ammonia leakage mathematical model,select appropriate boundary conditions,simulate different ammonia leakage process under different leakage speed and different ventilation conditions,summarize the rules by comparing density nephogram,velocity vector graph and the time-dependent concentration curves,then divide inhalational reaction zone,injured zone,seriously injured zone and lethal zone in refrigeration station affiliated room according to ammonia gas density nephogram.(4)Finally,give preventive measures of ammonia leakage by combining the actual situation of the research object and comparing the weight of every factors.Then made emergency measures from the ammonia alarm’s installation position,selection of draft type,divide of emergency zone and the other aspects by analysising the simulation results.