二氧化碳管道全尺寸爆破试验

Full-scale burst test of CO_(2) pipeline

[目的]碳捕集、利用与封存(Carbon Capture, Utilization and Storage, CCUS)是减少大气中CO_(2)含量的关键技术之一,超临界/密相态CO_(2)管道运输是将CO_(2)从捕集点输送至封存点最经济、最可行的方法。对于超临界/密相CO_(2)的管道设计而言,关键要求是管道产生裂纹后阻止管道的长程韧性断裂,全尺寸爆破试验是目前验证管道在发生爆裂时能否止裂的最直接手段。[方法]据调研,国外共开展了11次全尺寸爆破试验。考虑到国内外制管工艺的差异性以及实际CO_(2)运输的不同情况,为探究中国超临界CO_(2)管道的止裂韧性,成功开展中国首次CO_(2)管道全尺寸爆破试验。试验采用X65钢级、外径323.9 mm、壁厚7.2~7.6 mm的焊管,试验气体的组成为95%CO_(2)+4%N2+1%H2,试验压力为11.85 MPa,试验温度为12.6℃。[结果]CO_(2)管道全尺寸爆破试验进展顺利,管道裂纹从起裂管开始扩展,在起爆位置西侧两根管道的环焊缝处环切止裂,在起爆位置东侧由于管道母材韧性止裂,试验钢管表现出典型的韧性剪切断裂特征,采集到裂纹扩展速度、压力及温度等多项重要试验数据。[结论]该试验为中国掌握百万吨级CO_(2)输送管材研制、管道设计及建设技术提供了重要数据支撑,标志着中国在CCUS技术研究领域取得了重要的突破性进展。

[Objective] Carbon Capture, Utilization and Storage(CCUS) is a pivotal technology for reducing atmospheric carbon dioxide levels. The pipeline transportation of supercritical/dense-phase CO_(2) stands as the most cost-effective and practical means of conveying CO_(2) from capture sites to storage locations. In supercritical/dense-phase CO_(2) pipeline design, the key requirement is to mitigate long-range ductile fracture following the occurrence of cracks. At present, the most direct means for verifying the pipeline's fracture resistance during a burst event is full-scale burst tests. [Methods] An investigative study revealed that a total of 11 full-scale burst tests have been carried out abroad.However, considering the disparities in pipe manufacturing processes and the different situations of actual CO_(2) transportation, in order to explore the crack arrest toughness of China's supercritical CO_(2) pipelines, the first full-scale burst test of carbon dioxide pipelines in China was successfully carried out. The test employed welded pipes made of Grade X65 steel, featuring an outer diameter of 323.9 mm and a wall thickness ranging from 7.2 mm to 7.6 mm. The test gas was composed of 95% CO_(2), 4%N_(2) and 1% H_(2). The test pressure reached 11.85 MPa,and the temperature was maintained at 12.6 ℃. [Results] The test results indicated a successful execution of the full-scale burst test on the CO_(2) pipeline. The crack propagated along the pipeline from the crack initiating pipe. On the west side of the burst initiation location, the crack was arrested by ring-cutting at the circumferential weld of the two pipes. On the east side of the burst initiation location, the crack was arrested due to the toughness of the pipe base material, manifesting the typical characteristic of ductile shear fracture. Furthermore, crucial data regarding crack propagation speed, pressure and temperature were collected during the testing process. [Conclusion] This test yields crucial data for China to acquire expertise in the development, design and construction technology of million-ton carbon dioxide transportation pipelines,marking China's important breakthrough in the field of CCUS technology research.