基于多相流模拟的原油输送管道内腐蚀预测
Prediction for internal corrosion of oil pipelines based on multi-phase flow simulation
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摘要: 因油中携带的溶解了腐蚀性杂质的水在管道低点或流动死区聚集导致管道内腐蚀而发生穿孔的问题越来越突出, 基于此, 针对管输原油含水量低、原油透光性弱、难以通过传统的试验方法确定油水两相流的流动状态的问题, 运用流体仿真软件Star-ccm+, 结合输油管道实际工况, 对低含水率(含水量体积分数不高于1%)的原油在管道内的油水两相流进行模拟计算, 结果表明: 当前输油条件下, 距离三通2 m后的盲管段内的流体基本不再流动, 管道底部水的体积分数比管道上部高12.2%, 水发生明显沉降, 据此, 对输油站内管道腐蚀情况进行预测, 进而确定了安全运行重点监测部位。Abstract: In recent years, piercing of pipelines induced by internal corrosion has occurred frequently due to accumulation of water with corrosive materials contained in crude oil in lower points or dead flow zones of the pipeline. With low water contents, crude oil in pipelines has low transparency. Accordingly, conventional tests can hardly be used to determine conditions of oil and water flows. Instead, the Star-ccm+ simulation software is used depending on actual working conditions of the pipeline for simulation and calculation of oil and water flows within the pipeline for oil with low water contents (volume fraction is not higher than 1%). The results show that, under the current oil transportation conditions, fluids in the blind pipe 2 m after the tee connection can hardly flow with significant deposition of water and with volumetric fractions of water in bottom section of the pipeline 12.2% higher than those in upper sections. Accordingly, key sections with higher potentials for corrosion in pipelines of pump stations are predicted.