The Quantitative Assessment And The Accident Consequence Analysis Of Large Crude Oil Storage Tank

With the development of the oil reserve strategy, our country has been in the rapid growth of large-scale oil storage tank construction, and the intensification of reserves storehouse and the tendency of large-scale storage facility have been the main direction of the development of oil reserve project. This kind of trend is beneficial for official crude oil reserve, though, brings about catastrophic accident consequence. Given this background, it’s essential to give quantitative safety assessment and to predict major accident consequence.In this paper, through the analysis the hazardous characters of crude oil, the recognition of hazardous and dangerous factors in the crude oil storage places, the draw of fault tree on the fire explosion accident of crude oil tanks, the solution of minimal set collection of the fault tree in the help of Fault Tree software, it’s concluded that the structural importance of basic events, which provides the reference for the assessment index of fuzzy mathematics and for the weight calculation. By looking up the domestic and foreign typical tank accident data, statistics of tank causes of accidents and type of accident, analysis of possible accident consequences with respect to the crude oil storage, they provide case support for the simulation analysis of accident consequence.Using the fuzzy mathematical assessment method and Mond assessment method, it constructs the quantitative assessment system of the oil storage places. Fuzzy mathematics method gives an overall security level of the oil storage tanks, at the same time, based on Matlab programs, it gets the matrix solution of the characteristic roots and characteristic vectors and the check of consistency, overcome the problem of the solution of multi-order matrix, greatly simplifies the computation. Under Mond assessment method, it carries on the quantitative assessment for crude oil storage tank unit, gives assessment criteria on fire disaster, explosion index and toxicity index of the assessment unit material. As for the condition of numerous coefficient related to Mond assessment method and intricate assessment index, it programmed the software of Mond assessment by using Visual studio software and VB language, realizes the software-based on Mond assessment method. Analysis of fault tree, analytic hierarchy process, and fuzzy mathematics and Mond process, the combination of the four assessment methods avoids the defect of a certain assessment method leading to the distortion of the assessment results.It takes comprehensive analysis of the oil spill, diffusion, fire, explosion, boil over and spillage accident. For the leakage model, the calculus method was adopted to get the more accurate prediction formula and it also predicts the leaking aperture diameter for 20% to 100% diameter, leak leakage time for 30 minutes; Integrated with a Gaussian diffusion model,also with the aid of Matlab, it gives the spread of the different wind speed range, under the two circumstance of an crude oil spill in intermediate dike (less leakage) and all fireproofing dike (more leakage), also gives danger explosion zone under the direction of the wind, side direction of the win and health hazard area; For the pool fire accident, it adopts fire model by Mudan pillar, utilities Matlab program to overcome calculation difficulty of view factor when it winds, respectively calculates the death radius, the radius of the second degree burns, first-degree burns radius and property damage radius under the crude oil tank area of fire, intermediate dive pool fire and fireproofing pool fire three cases, with the different wind speed, downwind direction and upwind direction. For crude oil storage tank area fire boil over all splash, it forecasts the splash time in different crude oil tank liquid level height when the water cushion layer is 1 m, and calculates water amount of fire fighting and the dosage of bubble under the circumstance of the cooling cupping within 1.5 D range, as well as the fire extinguishing fire water needed for 6 hours. Take A-5Nomex fire combat gear as an example, it gives the safety security distance of fire fighter rescue personnel in the different speed of wind, downwind direction and upwind direction. By using TNT equivalent method, it calculates the death radius, serious injury radius, light injury radius and property damage radius under the three circumstances of the explosion in the process of overhaul of un empty oil tank, the second explosion resulted from the explosion of half oil tank and diffusion explosion after the leaking of crude oil, also realizes software-based of explosion model with the aid of Visual Studio.This paper resolves the problems of hand computation difficult to complete or too large calculated amount in the course of analysis of quantitative assessment and accident consequence, by using Matlab program and Visual Studio software. Through quantitative assessment to understand the security level of the oil storage place, it makes comprehensive safety management at the same time, contains respective characters; Through accident consequence analysis, it provides scientific basis and reference for establishing the targeted accident emergency rescue preplan and enforcing effective field control and processing.