论文部分内容阅读
按常规方法设计的管道对含蜡原油进行输送时,往往忽略了含蜡原油管道设计中的一个关键问题,即将含蜡原油特性考虑在内的最佳管径的选取,这很可能导致管道凝管,使允许停输时间超过最大许可时间,泵不能提供再启动流动所需的功率。非牛顿紊流是最差的设计条件,此时流动已经开始,再启动后的非牛顿层流流体在最低的环境温度下,其再启动流量低于设计输量。这些条件表明需要最大压力(或功率)才能满足设计输量要求。Harvey等人推荐,对于牛顿流,可以采用Fanning方程;对于紊流,可使用Blasius摩阻系数方程,以及层流时使用Hagan-Poiseuille方程。对于非牛顿流体,紊流时可以使用相同方程,但要用塑性粘度代替Hedstrom方程用于层流。
Pipelines designed in the conventional manner tend to overlook a key issue in the design of waxy crude pipelines when transporting waxy crude, the selection of the optimal pipe diameter, taking into account the characteristics of the waxy crude, which is likely to lead to The tube, allowing the shut down time to exceed the maximum allowable time, does not provide the power required to restart the flow. Non-Newtonian turbulence is the worst design condition, and the flow has started. The restarted flow of non-Newtonian laminar fluid at the lowest ambient temperature is lower than the design flow. These conditions indicate that maximum pressure (or power) is required to meet the design throughput requirements. Harvey et al. Recommend that the Fanning equation be used for Newtonian flow, the Blasius friction coefficient equation for turbulent flow, and the Hagan-Poiseuille equation for laminar flow. For non-Newtonian fluids, the same equation can be used for turbulent flow, but the plastic viscosity is used instead of the Hedstrom equation for laminar flow.