Research On The Diffusion Of An Enterprise Liquid Ammonia Tank Leakage Based On Numerical Simulation

Liquid ammonia is one of the important chemical raw materials,can be used in the production of nitric acid,explosives,urea and other products,and is often used as the raw material of metallurgy,semiconductor and medicine.However,due to the special risk of ammonia,ammonia leakage accidents occur frequently in various industries,causing fire and explosion in serious cases.In recent years,due to the frequent occurrence of accidents caused by ammonia leakage,a large number of people have been poisoned and injured,and the social environment has been very bad.This paper,based on an enterprise liquid ammonia storage tank,studies the hazards effects of liquid ammonia leakage diffusion,and provides guidance for enterprises to prevent and emergency rescue treatment of liquid ammonia leakage.By consulting the relevant literature,the combination of physics and chemistry nature,the hazards of liquid ammonia and ammonia exposure concentration criterion,spread of ammonia leakage in the air may cause toxicity hazard area division.Combined with typical accident statistic analysis,to study the mechanism of leakage,and has been widely applied at home and abroad and compares four kinds of diffusion model,last choose gaussian(plume)model as this thesis,the mathematical model of liquid ammonia leakage diffusion,and theoretical calculation of leakage diffusion concentration mathematical expressions are given,which provides the theoretical basis for the simulation research.The article through to identify major hazard identification of the liquid ammonia tank in on the spot investigation for wade ammonia enterprise,and using the fault tree analysis method to find out all the basic events leading to the liquid ammonia leakage.Through calculating the structure importance degree of the basic event,the main factors that cause the ammonia leakage accident are the equipment such as tank corrosion,valve fault,seal failure and alarm instrument failure,and put forward the corresponding control counter measures to give guidance.In this paper,using the computational fluid dynamics CFD-FLUENT software to this enterprise liquid ammonia tank leakage diffusion numerical simulation research,get the ammonia leakage diffusion concentration under different wind conditions of time and space distribution rule,and used gaussian diffusion model theory to calculate,and compared and verified the two results,get the influence of different toxic hazard area,Based on the simulation results,dividing the warning evacuation zone,and combined with the distribution of the tank in the factory,establishing reasonable personnel evacuation route.Puts forward the concrete measures of prevention and control of liquid ammonia tank leakage,and emergency rescue disposal countermeasures in the condition of accident,and provide technical support for ammonia enterprises in revising the emergency rescue plan.