成品油管道混油拖尾对切割浓度的影响

成品油顺序输送管道因混油拖尾现象的存在，采用恒浓度切割方案可能造成前行油品无法充分利用质量指标裕量，而输送顺序发生变化时后行油品质量指标无法达标的情况。为此，探讨了混油拖尾现象的形成机理，并以中国石油西部成品油管道为例，分析了成品油顺序输送过程中混油尾的发展规律。基于此，计算给出了西部成品油管道兰州站和兰郑长管道郑州站的混油切割方案，并提出随着油品质量指标及流量等运行参数的变化，应根据油品输送顺序的不同，采用不同的混油浓度切割方案，即混油头切割时后行油品的切割浓度应高于输送顺序相反时混油尾中前行油品的切割浓度。（图2，表3，叁10）

Effects of mixed oil tailing of products pipeline on cutting concentration

The behavior of mixed oil trailing exists in a refined oil batch transportation pipeline. Accordingly, when a constant-concentration cutting approach is used, forward refined oil possibly fails to meet the allowance for quality, and trailing refined oil may not be up to the quality standard once the delivery sequence changes. In this paper, the formation mechanism of mix oil trailing is discussed, and the evolution of mixed oil tail during the refined oil batch transportation is analyzed for PetroChina＇s West Products Pipeline. Then, through calculation, the mixed oil cutting approaches are proposed for Lanzhou Pump Station in the West Products Pipeline and Zhengzhou Pump Station in the Lanzhou-Zhengzhou-Changsha Products Pipeline. Moreover, it is suggested that different-concentration cutting approaches are adopted with the change of operating parameters like oil quality and flowrate, depending on delivery sequence, in other words, the cutting concentration of trailing refined oil when the mixed oil head is cut should be higher than the cutting concentration of forward oil in the mixed oil tail when the delivery sequence is opposite. （2 Figures, 3 Tables, 10 References）