含蜡原油柴油顺序输送中柴油对蜡沉积物的冲刷作用

针对含蜡原油成品油在顺序输送中管壁上会产生蜡沉积物的问题 ,利用管流实验环道模拟了 0号柴油对管壁处蜡沉积物的冲刷实验。结果表明 ,柴油对靠近油流 1/ 3厚度的蜡沉积物的冲刷速率远大于对其余 2 / 3厚度的蜡沉积物的冲刷速率 ,说明这两层沉积物的性质和强度明显不同。但在一定油温和油流剪切应力下 ,每层中柴油对蜡沉积物的冲刷速率变化不大。对两层蜡沉积物分别建立了冲刷速率与油流温度及剪切应力关系的经验模型。利用该模型和壁面蜡沉积模型 ,以库尔勒鄯善输油管道为例 ,计算了 0号柴油与原油顺序输送时管道末端受污染超标的柴油的量 ,说明原油批次输送时 ,在管道末段必须采取清管措施 ;否则 ,蜡沉积物对后输柴油的污染相当严重。

Effect of diesel on wax deposit during batch transport of waxy crude and diesel in a pipeline

Some experiments were conducted in a flow loop to simulate the effects of a diesel stream on the wax deposits on the pipe wall during batch transport of waxy crude and refined petroleum products in a pipeline. It is found that the erosion rate of outer wax deposit with one of three in thickness near the oil stream is much higher than that of inner wax deposit. The properties and strengths of deposits in the two layers are different. The erosion rates of both layers are the same approximately at a certain temperature and shear stress of the diesel stream. On the above basis, an empirical model was developed for correlating the erosion rate with the oil temperature and shear stress. By using this model together with a wax deposition model and exemplifying the Korla Shanshan pipeline for transporting crude and diesel No. 0 in batch, the quantity of the diesel out of quality due to contamination by wax deposit at the outlet of the pipeline was estimated. It is demonstrated that the pipeline is necessary to be cleaned after the crude batch,in order to eliminate the following diesel contaminated with the wax deposit.