原油差温顺序输送停输初始状态及安全性

原油差温顺序输送管道不同停输初始状态对应不同的安全停输时间，停输安全性是该输送工艺的重要技术问题。为了获得停输初始状态对停输安全性的影响规律，定性分析了一个输送周期内不同时段的停输安全性特点，通过引入停输时机的概念和定义无量纲排空时间定量分析了不同停输初始状态的相对停输安全性。结果表明：高凝油油头到达进站口时停输最危险；不同停输时机的无量纲排空时间相差明显，即不同停输时机再启动的难易程度或停输安全性相差较大，且差异程度随停输时间延长而增大；对于存在停输危险的停输时机，无量纲排空时间总会在某一停输时间下趋于无穷大，表明该停输时间下，再启动不会成功。研究结果可为原油差温顺序输送管道合理安排停输检修计划或定性判断停输安全时间提供技术支持。（图4，表4，参13）

Initial state and safety of pipeline shutdown in the thermal differential batch transportation of crude oil

Different initial shutdown state for the thermal differential batch transportation pipeline corresponds to different safe shutdown time, and the shutdown safety of is a key technical issue for this transportation process. In order to obtain the influence of initial shutdown state on the safety, this paper qualitatively analyzes the features of safety of different shutdown period in one transportation cycle and quantitatively analyzes the relative safety of different initial state by introducing the concept of shutdown time and definition of dimensionless emptying time. The results show that it is most dangerous to shutdown when the oil head with high pour point reaches the inlet of pump station. There are obvious differences in dimensionless emptying time at different shutdown time, that is, the difficulty to restart at different shutdown time or safety is very different from each other and the differences increases with the increase of shutdown time. For the shutdown time with risks, the dimensionless emptying time will tend to infinite under some shutdown time, which indicates that the restart will be a failure under that shutdown time. The results can provide a technical support to the reasonable arrangement of repair schedule or qualitative judge of safe shutdown time for the thermal differential batch transportation pipeline. （4 Figures, 4 Tables, 13 References）