Study On The Impact Of Crude Oil Storage Tank Heavy Accidents On The Surrounding Environment And Quantitative Evaluation

The catastrophic accidents such as fire,explosion,and leakage caused by crude oil fuels that are inflammable,explosive,easy to evaporate,and easy to flow have been on the rise year by year with the intensification of China’s crude oil reserves and the large-scale development of storage facilities.Chain-linked disaster accidents in oil depots not only pose serious threats to the safety of facilities,equipment,and personnel,but also may cause secondary disasters such as large-scale environmental pollution.Therefore,it has an important practical significance in reducing the probability of leakage and igniting events,improving the management level in the tank area to establish a model for assessing the environmental impact of heavy tank accidents,and determine the range of influence of the tank accident on the surrounding environment and the corresponding degree of risk according to the construction environment of the oil depot and the accident receiver of tanks.At present,there are many researches on the environmental risk assessment of oil depots at home and abroad.However,there are few simulation studies on the leakage of crude oil storage tanks that have evolved into specific situations,such as pool fires,BLEVE,and oil behavior and fate at sea.Therefore,this article analyzes cases of accidents such as fire,explosion,and leakage of tanks,and summarizes the major accidents and induced causes of tanks.Then,according to the location of the establishment of the reservoir,three types of heavy crude oil storage tank accident models in the sea area,public construction area,and ecologically sensitive area were established,and their adaptation assessment methods were theoretically analyzed.What is more,the PHAST software was used to simulate the pool fire and BLEVE of different capacity crude oil storage tanks to quantitatively predict the relationship between accident impact radius and tank capacity.For the coastal area,the paper combines the oil spill behavior and fate theory to build a scenario model for large-scale accidents of offshore oil spills from crude oil storage near the sea.Then,combined with the data of D sea area topography,water levels,and wind fields,the terrain file is generated using the MIKE ZERO numerical simulation software,and the water level time series files,water level boundary conditions,wind field time series files were created successively.Based on MIKE 21 FM module,a two-dimensional hydrodynamic environment model were built,and comparing the measured data and simulation results after solving,the model was determined(reducing fluid resistance)through increasing the Manning coefficient and reducing the eddy viscosity coefficients,densing meshes,and other methods.Then combined with the hydrodynamic field,the author used the MIKE 21/3 Oil Spill module to establish an oil spill prediction model,and simulated the oil film diffusion law and oil spill weathering under typical working conditions,and based on the discussion of the impact factors of oil spill results,the 3 1 working conditions consisting of different wind speeds,wind direction,different oil spills,and oil spill points were studied as representative conditions,and the impact of various factors on the oil film transport and weathering process was quantitatively analyzed.The results show that:(1)The drag force of the flow field and wind under typical working conditions is combined on the water to spread the oil from the western coastline along D seaward to the inward sea area.After 12 hours of oil spill,the oil film will land on the southwest coast and drift along it.This process lasts for about 14 hours,and the oil spill will pose a serious threat to sensitive shoreline targets.(2)With the increase of oil spillage time under typical conditions,the evaporation rate of the oil film gradually increases,and it tends to be stable at about 24%after one day;the emulsification rate continuously decreased with time,after 9 hours it became stable,and the emulsified moisture content was approximately 78.2%;the oil dissolution rate tended to stabilize after 9 hours of oil spill,which was approximately 0.66%.(3)The diffusion area of the oil film is positively related to the wind speed and oil spillage.The area of oil film diffusion area and the drift track are affected by the wind direction to a certain extent,but are mainly controlled by the flow field.At the same time,the oil film diffusion range and drift track of different oil spill points are different,and the influencing factors are mainly flow fields.(4)During the weathering process,the oil evaporation rate,the oil dissolution rate,and the emulsified moisture content are positively correlated with the wind speed,and the increase rate decreases with the increase of the wind speed,but the change of the wind direction has little effect on the weathering process.The amount of oil spilled has little effect on the evaporation rate of oil and the residual rate of sea oil.Although the oil evaporation rate has decreased as the amount of oil spilled increases,and the remaining rate of sea oil has increased,the change trend is not obvious.(5)The water temperature has a great influence on the process of oil spill dissolution,evaporation,and emulsification.It has a positive correlation with the evaporation rate and emulsification rate of the oil spill,but it has a negative correlation with the oil dissolution rate.Finally,according to the results of oil spill diffusion and transportation,the applicable oil spill control measures and specific equipment specification requirements were analyzed and calculated.