裸露输油管道保温层对停输温降的影响

Effect of Thermal Insulation Layer of Exposed Oil Pipeline on Temperature Drop during Shutdown

热油管道在运输过程中不能避免停输,由于没有土壤保温,其保温层对停输至关重要。根据东北地区裸露输油管道实际运行情况,建立了输油管道停输温度场的物理模型,利用CFD软件分别对保温层失效前后的温度场进行了停输模拟,得到稳态和非稳态下温度场分布规律。模拟结果表明:保温层失效后温度变化率远大于失效前的温度变化率,失效后管道中心与管壁附近油流温差较大,安全停输时间由失效前的9 d降低到失效后的7 h。

The hot oil pipeline shutdown can't be avoided during its transportation and its thermal insulation layer plays a vital role in its shutdown due to absence of soil's thermal effect.Established is a physical model of oil pipeline temperature field in its shutdown according to the actual situation of exposed oil pipelines in the northeast of China,CFD software is used to simulate temperature fields in shutdown respectively before and after failure of thermal insulation layer and obtained are the rules of the temperature field distributions in steady state and unsteady state conditions.Simulation results show that temperature change rate after failure of thermal insulation layer is far more than that before failure,oil temperature difference between oil pipeline center and its wall vicinity is large after failure and safety shutdown time is reduced from 8 days before its failure to 7 hours after its failure.