Abstract: The total heat transfer coefficient of two pipe laid in one dutch was got by using thermal conductivity. Established the shutdown temperature drop calculation model and simulated the unsteady shutdown state by using PISO methord. According to western pipeline historical data and the reality of western crude oil pipeline and product oil pipeline，calculated the shutdown temperature drop and analysis the results. Found out the potentials of shutdown dangerous sections. Provided references for the design and the operation management of northwest two pipe laid in one dutch in our country.

Key words: Double pipelines in one ditch, Overall heat transfer coefficient, Shutdown temperature drop, Soil temperature field

摘要： 引入导热形状因子得到同沟敷设管道的管段总传热系数，建立了同沟敷设热油管道停输温降的计算模型，并采用ＰＩＳＯ算法对停输瞬态问题进行模拟。利用西部管道沿线的历史数据及西部原油成品油同沟敷设热油管道的实际情况计算了沿线停输温降并进行了对比分析，找出了潜在的停输危险截面，为我国西北地区同沟敷设管道的设计与运营管理提供了参考。

关键词: 同沟敷设 , 总传热系数 , 停输温降 , 土壤温度场