Abstract: According to changing the type of oil in the process of transportation by the above ground pipeline, which may cause the pipe rack bending and thermal stress damage. The thermal expansion and thermal thrust of the compensator which has an important effect on the pipe rack bending were analyzed. Thereby, the axial horizontal displacement and horizontal thrust were determined. Clear and definite the reason for pipe rack bending. Combined with the type of medium transport in the pipe, the medium temperature, the pipe model, the pipe arrangement craft and other factors, the thermal stress of pipe and the allowable stress range were determined, To judged whether the pipe will produce destructive thermal stress and by the experience formula for further confirmation.

Key words: Oil pipeline , Pipe rack ,  Thermal stress , Compensator

摘要：        针对地上输油管道使用过程中变更输送油品可能引起的管架推弯及管道热应力破坏，分析了对管架推弯有重要影响的补偿器的热胀量及热态推力，从而确定了固定管架的轴向水平位移量及所受的水平推力，明确了管架推弯的原因。结合管道内输送介质的种类、介质温度、管道型号、管道布置工艺等因素，确定了管道热应力及许用应力范围，对管道是否会产生热应力破坏进行了判断，并通过经验公式进行了进一步的验证。

关键词: 输油管道 , 　管架 , 　热应力 , 　补偿器