成品油管道输送高差混油模型研究

在倾斜管道顺序输送中 ,输送油品的物性差异在重力作用下影响混油的形成。分析了油品物性对混油过程的影响 ,利用与混油区的物质分布相关的轴向有效分散系数 ,建立了管道顺序输送高差混油模型。同时考虑了粘度和密度的变化 ,采用Crank Nicholson型隐式格式构造差分方程 ,并进行了数值求解。利用计算实例对雷诺数、倾角和输送长度等混油影响因素进行了分析。结果表明 ,倾角对混油的影响随着输送距离的增加和雷诺数的提高逐渐减小 ,特别是在大于临界雷诺数的高度湍流和长距离输送时 ,倾角对混油的影响相当小

Development of model for contaminated oil product cased by elevation difference in multiproduct pipelines

The difference of physical properties of oil products under action of gravity effect has some influence on the contaminated oil products in the undulate multi-products pipeline. The effects of different properties of oil products on contamination of oil products were analyzed, on which the virtual axial dispersion coefficient related with mass distribution in mixing section was utilized to establish a model of contaminated product in a slanting pipe. In consideration of viscosity and density changes,the model was solved numerically by using Crank-Nicholson implicit difference scheme. The factors affecting contaminated product such as Reynolds number,piping length and inclination angle of pipeline were analyzed by means of several examples. The computation results showed that the effect of inclination angle of pipeline on contaminated product decreased gradually with the increase of piping length and Reynolds number. Particularly,the effect of inclination angle of pipeline on contaminated product became invisible, when the oil products in pipeline was in the state of completely turbulent flow with Reynolds number greater than the critical Reynolds number and the pipeline was considerably long.