原油顺序输送管道寿命的分析研究

Study and analysis of lifetime of crude oil batching transportation pipeline

分析了冷热油顺序输送工艺中冷热油交替、管道停启、压力波动对管道产生的交变应力。针对原油顺序输送埋地直管道的嵌固段,采用名义应力法和累计损伤理论进行管道疲劳寿命分析,得出埋地直管道交变热应力对管道寿命的影响较小,停启对管道寿命影响较大。采用名义应力法进行顺序输送管道寿命分析应做好3项工作:(1)实测管道的载荷谱,找出年周期内的管道应力变化规律;(2)对现有新型管材做疲劳试验,总结出比较准确的管材S-N曲线;(3)找出管道腐蚀和管道初始裂纹在管道交变应力作用下对管道寿命的影响规律。

The alternate stress of the pipeline caused by the cool and hot oil alteration, pipeline start-stop operation and pressure fluctuation is analyzed during the cool and hot oil batch transportation. The nominal stress approach and the accumulative damage theory are adopted in order to analyze the buried pipeline fixing sector. The results show that the alternating thermal stress has a little effect on the pipeline lifetime, while start-stop operation has a great effect. The three problems to be solved at present in analyzing the pipeline lifetime by using the nominal stress approach are: (1) in-situ measurement of the load spectrum of the pipeline to find out the stress change rule of the pipeline within annual period; (2)fatigue test on the existing novel pipeline to summarize the relatively accurate S-N curve of the pipeline; (3) locating the influence rule of pipeline corrosion and initial crack on the pipeline lifetime under the action of alternate stress.