Study On Safety Distance And Protective Measures For Oil Tanks Against Oil Gas Explosion

In recent years,with the expansion of the scale of the oil depots,the consistent increase of the capacity of a single tank and a wide variety of types of storage tank,the oil storage shows the new feature of large capacity and the trend of integration.Accordingly,the risk of the leakage and explosion of the oil tanks is on the rise,which brings new challenges to the security and protection work.In order to optimize the safe distance of the oil tanks in the oil depot,the leakage diffusion process of the oil tank and its damage to the structure of the adjacent oil tank have been studied in this thesis based on the numerical simulation method.The main research and conclusion are as follows:Taking the fixed roof oil tanks with the capacity of 10000m3 as example,the oil tank leakage accident is simulated based on the software FLACS,which focuses on analyzing atmospheric dispersion and explosion.And the observed object is the changes in volume and concentration of flammable vapor cloud.The study found that the volatile gas expands slowly from center to around after the oil tank leaks,creating a certain volume of flammable vapor cloud around the leak point.And most of the gas in it is in the range of volume and concentration between the explosive limits.Thus we can assume that the distance between the two oil tanks is equal to the distance between the explosion center and the adjacent oil tank.The author has chosen three sizes of fixed roof oil tanks,that is,10000m3?5000m3and 1000m3.Through using ANSYS/LS-DYNA to calculate and analyze their dynamic response under blast load,the security of the distance between the oil tanks basing on the current specifications has been explored.The results show that such kind of distance only considers fire-protection,which means that the structure of the adjacent oil tank may be damaged if there's an explosion.Since the current distance can't meet the requirements of explosion-proof,the author tries to find the reasonable distance according to different sizes of fixed roof oil tanks and also judge its feasibility through using the numerical simulation method.The study found that the safe distance of such large oil tanks like 5000m3 and 10000m3should be expanded to about 28 meters.However,as to the middle-sized oil tanks with the capacity of 1000m3,only expanding the distance is less economical and it's necessary to build the blast wall.The thesis also makes an analysis of the explosion-proof effect of the blast wall.Through making the height of the blast wall,relative to the height of the oil tank,as the main variable,it studies the different effects of different heights.According to the findings,the blast wall can effectively resist the explosion.As the relative height increases,the blast wall will have a more obvious explosion-proof effect.Given safety and economic concerns,the blast wall can play a role of explosion proof effectively when it is two-thirds as tall as the oil tank.