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

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