Research On Risk Assessment Technology For Leakage Accidents Of Urban Buried Oil Pipelines

Pipeline is an important energy lifeline. In order to accelerate the construction of urban and infrastructure network recent years, the level of regions which a large number of oil pipeline crossed have changed. The level of some areas changed from the original 1 degree to 3 or 4 degree. Various types of pipelines arranged in a crisscross pattern in these areas, including communication pipeline, heat pipeline, gas pipeline and water pipeline, etc. Because of the loopholes in planning, construction, supervision, maintenance and other aspects of, urban buried oil pipeline has gradually become a hidden disaster risk. Therefore, to ensure the safe operation of urban underground oil pipeline is imminent.This paper takes the town buried oil pipeline as the research object The main research contents are as follows:(1) Bow-tie model of typical urban buried pipeline is established. According to Bow-tie model to simulate the pipeline risk factors identification and establish the index system of buried pipeline failure possibility. Using the analytic hierarchy process (ahp) to obtain the weight of each influence factor, combined with fuzzy comprehensive evaluation method for pipeline failure probability level.(2) Urban underground pipeline accident consequences are analyzed based on Bow-tie model, separately to discuss the process of oil leakage, oil spill extended procedures, processes and spill oil spill drift evaporation process and the establishment of appropriate mathematical models. Accident consequences model and guidelines for accident injuries are proposed, combined leakage process mathematical model to calculate the range effects of the accident and lay the foundation for the consequences of the accident level evaluation(3) For oil leakage into culverts accident, using Fluent software simulation of semi-enclosed spaces of oil vapor diffusion law, to get the hazardous area and explosion limit concentration change curve. Analysize the concentration diffusion trend, put forward the risk control measures, and use the location of the explosion and the concentration of the semi-enclosed space for consequences calculation(4) Use "11-22" incident as the research object instance to calculate the consequences of damage radius and determine the scope of the accident, the results and the actual situation of the accident are consistent. The consequences of the evaluation grade is 4, the possibility of failure grade IV grade, based on a risk matrix is judged that the risk level is high accident risk.(5) Combined city buried pipelines Bow-tie model analysis with Fluent software simulation results, propose measures to prevent accidents and control measures.City buried pipeline leak into the inner culvert consequences more serious than into open channel and anti rushed to the road,and risk assessment process for the accident is also more complex. Paper based on Fluent software to establish a half closed space evaporating diffusion model can offer reference for the study of the similar accidents, according to the results of numerical simulation are applied to the consequences of risk evaluation methods of the evaluation results is more precise.