热载荷约束下含单腐蚀西气东输管道受力分析

天然气的常规输送方式往往为管道输送，作为一种清洁能源被广泛使用，在西气东输工程中大量采用了高强度高钢级的管道以满足输气量。为了抑制天然气水合物的生成，在输气途中会设置加热站来提高天然气的温度，在内压和热应力的共同作用下会使得管道更加容易失效，尤其是当管道存在腐蚀的条件下。因此建立了含腐蚀的西气东输管道模型，在不同输气温度条件下运用ANSYS软件对2种腐蚀形式、不同的腐蚀深度进行了热固耦合有限元分析。结果表明，在常温下，矩形腐蚀和圆形腐蚀的腐蚀深度允许量均接近管道壁厚的一半；当天然气温度加热到30 ℃后，二者允许的腐蚀深度在管道壁厚的0.2~0.3倍，若温度达到40 ℃甚至更高，则允许的腐蚀深度仅为管道壁厚的0.1倍。因此在西气东输工程中，对于单腐蚀而言，应合适控制输气温度在30 ℃以内，既能有效抑制水合物的生成，同时能延长管道的使用寿命。

Force analysis of pipeline in West-east Gas Transmission with single corrosion under thermal load constraint

Natural gas transportation is usually carried out by pipeline.As a kind of clean energy，it is widely used.In the West east Gas Transmission Project，a large number of pipelines with high strength and high steel are adopted to meet the demand of gas transmission.In order to inhibit the formation of natural gas hydrate，heating stations will be set in gas way to improve the gas temperature，the interaction of internal pressure and the thermal stress will make the pipeline more prone to failure，especially when the pipeline corrosion conditions.Therefore，the model of the west east gas pipeline with corrosion was established.Under the condition of different gas transmission temperature，the thermal stability of the two corrosion forms and corrosion depth was analyzed by ANSYS software.The results showed that under normal temperature，corrosion depth and corrosion corrosion of rectangular circular allowed were close to half of the pipe wall thickness，when the gas temperature to 30 ℃ after heating，the corrosion depth two allowed between the pipe wall thickness of 0.2 to 0.3 times，if the temperature reaches 40 ℃ Celsius or higher，corrosion depth allow only 0.1 times the pipe wall thickness.Therefore，in the West east Gas Transmission Project，for single corrosion，the gas transmission temperature should be controlled within 30 ℃，which can effectively inhibit the formation of hydrate and prolong the service life of the pipeline.