A considerable amount of oil contamination is caused by the presence of the trailing oil. This paper aims to simulate and analyze the influences of trailing oil on the quality of oil products in undulating sections. By studying the formation mechanism of mixed oil at inclining pipeline sections and the influences of velocity and oil batches on incline sections, as well as both ups and downs, the correlation is obtained between replacement time of different batches and velocity at various sections. By applying FLUENT 14.5, the maximum time of volume fraction of contaminant oil from 1% to 99% is simulated at cross-sections among different pipeline sections. Aiming at the relationship between oil product replacement time and change time of mixing section volume fraction and flow velocity, the mixing increment of undulating section relative to straight section is obtained. Combining with the empirical mixing length calculation equation, the equation for calculating mixing length considering terrain undulation is obtained. Combined with the actual operation data of Lan-Chengyu’s product oil pipeline, the error of the new mixed oil length calculation equation and actual oil mixing is 0.7966%. Excessive cutting amount of mixed oil will result in the waste of refined oil, and the less cutting amount will cause pollution of refined oil. The new mixed oil length calculation equation can more accurately guide the oil mixing cutting work at the oil station.

中文翻译：

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成品油管道顺次输送污染油量计算方法

大量的油污染是由尾随油的存在造成的。本文旨在模拟和分析起伏段拖尾油对油品质量的影响。通过研究管道倾斜段混合油的形成机理，以及速度和油批对倾斜段的影响，以及上下起伏，得到不同批次的置换时间与各段速度之间的相关性。应用FLUENT 14.5，模拟了不同管段间断面污染油体积分数从1%到99%的最大时间。针对油品置换时间与混合段体积分数和流速变化时间的关系，得到起伏段相对于直线段的混合增量。结合经验混合长度计算方程，得到考虑地形起伏的混合长度计算方程。结合蓝城玉成品油管道实际运行数据，新的混合油长度计算方程与实际混合油的误差为0.7966%。混合油切削量过大会造成成品油的浪费，切削量过少会造成成品油污染。新的混油长度计算方程可以更准确地指导油站混油切割工作。结合蓝城玉成品油管道实际运行数据，新的混合油长度计算方程与实际混合油的误差为0.7966%。混合油切削量过大会造成成品油的浪费，切削量过少会造成成品油污染。新的混油长度计算方程可以更准确地指导油站混油切割工作。结合蓝城玉成品油管道实际运行数据，新的混合油长度计算方程与实际混合油的误差为0.7966%。混合油切削量过大会造成成品油的浪费，切削量过少会造成成品油污染。新的混油长度计算方程可以更准确地指导油站混油切割工作。