Abstract: Before hot oil pipelines’ starting to convey,it is necessary to preheat pipes, and exactly forecasting the temperature of both medium inside pipes and surrounding soil during the process of preheating is the key to determine reasonable preheating time and the amount of preheating medium. Finite volume method was used to establish CFD simulation model to calculate heat transfer between underground pipelines and surrounding soil during the process of oilwater mixture preheating, and according to the analysis of temperature drop of the medium, a change rule conclusion of the temperature about medium inside pipelines during the oilwater mixture preheating period was reached, which can set corresponding oilconveyed technique and attain the goal of safety and saving energy. 

Key words: Hot oil pipelines,    ,  Mixture preheating,    ,  Temperature drop,   ,  Numerical simulation

摘要： 在热油管道启输前,需要预先对管道进行预热,为确定合理预热介质总量和预热时间,有必要预先知道预热过程中管道周围土壤温度场和管内介质温度的变化规律。用有限元法对以油、水混合预热过程中土壤传热进行数值计算,对预热管道管内介质沿程温降进行了分析,得出了油、水混合预热过程中输油管道管内介质温度变化规律,以此为依据确定相应的预热输油工艺,可使预热输油达到安全节能的目的。

关键词: 热油管道,    , 混合预热,    , 沿程温降,   , 数值模拟