埋地热油管道停输径向温降规律研究

热油管道的计划检修和事故抢修是在管线停输情况下进行的.停输后,管内存油油温不断下降,存油粘度随油温下降而增大,当增大到一定值后,会给管道再启动带来极大的困难,甚至会造成凝管事故.热油管道不仅存在轴向温降,而且还存在径向温降.为了确保安全经济地输油,在得出停输后轴向温降规律的基础上,还必须研究管路停输后的径向温降情况,以便更准确地确定允许停输时间.根据热油管道停输后油品轴向温降公式和径向传热规律,提出了传热定解问题并对其进行数学求解,得出了管道中油品径向温度的解析解,并编制了相应的软件,从而为更合理地确定在不同季节安全停输时间提供了科学计算依据.

Study on Radial Temperature Drop When Shutdown on Buried Crude Pipeline

Stopping transportation of the pipeline is necessary when breakdown occurs in the transportation systems and when equipment needs repairing periodically. When crude oil pipelines shutdown, the temperature of the oil left in the line drops and the viscosity increases. The process of restart up will become very difficult, and even blocking line will happen if the temperature drops to condensation point. For the sake of transporting oil safety, it is necessary to study the situation of radial temperature drop to make sure accurately the allowed shutdown time on the basis of the axial temperature drop obtained. A problem of determining solution on radial heat conduction is presented according to the axial temperature drop formula and radial heat conduction rule after oil pipeline shutdown. And the problem has been solved, the analytic solution formula of the radial oil temperature has been obtained, a corresponding software has also been programmed which provides a scientific basis for determining safe shutdown time in different season.