中文摘要：

采用显热容方法,建立架空管道停输温降数学模型,利用UFD软件针对典型停输工况进行数值模拟。根据管道内部液相原油平均流动速度的变化情况,对比分析了停输过程中自然对流换热过程的变化及影响。结果表明：从停输至原油全凝过程的后半程,可忽略自然对流换热的影响。研究结果进一步完善了原油相变传热机理,并可为长输管道停输维修时间及再启动条件的确定提供必要的支持。

英文摘要：

Shutdown temperature drop mode of aerial hot oil pipe was established by sensible heat capacity method. Typical operating conditions were simulated by UFD software. According to average velocity transformation of liquid oil in pipeline,the process and influence of natural convection were analyzed during shutdown process. The results show that since the second half of the crude oil solidification process,the influence of natural convection can be ignored. The results improved the crude oil phase change heat transfer mechanism,which can offer necessary support for the determination of shutdown maintenance time and restart up in long-distance hot oil pipeline.