地形起伏超临界CO2管道两端阀室放空动态模拟

1.中国石油大学(北京)碳中和示范性能源学院·油气管道输送安全国家工程研究中心·石油工程教育部重点实验室·天然气水合物国家重点实验室·城市油气输配技术北京市重点实验室;2.中国石油工程建设有限公司西南分公司

超临界CO2;放空;低温风险;相态变化

Dynamic venting simulation of valve chambers at both ends of supercritical CO2 pipelines with topographic relief
YAN Bing1,SHI Bohui1,CHEN Junwen2,TANG Xiaoyong2,ZAN Linfeng2,WANG Yanjing1,LI Yupei1,GONG Jing1

1.College of Carbon Neutral Energy, China University of Petroleum (Beijing)//National Engineering Reasearch Center for Pipeline Safety//MOE Key Laboratory of Petroleum Engineering//State Key Laboratory of Natural Gas Hydrate//Beijing Key Laboratory of Urban Oil and Gas Distribution Technology; 2.Southwest Branch of China Petroleum Engineering & Construction Corporation

supercritical CO2, venting, low-temperature risks, phase transition

DOI: 10.6047/j.issn.1000-8241.2024.05.009

备注

【目的】碳捕集,利用与封存(Carbon Capture, Utilization and Storage, CCUS)技术作为实现碳中和的重要手段,其中CO2的安全高效输送是关键环节。超临界相CO2管道输送已在国际上得到广泛应用,国内现已基本掌握了超临界CO2管道稳态输送的工艺规律,但对于具有起伏地形的超临界CO2管道放空作业的动态规律和安全风险认识尚不够深入。【方法】借助OLGA软件,建立具有起伏地形的超临界CO2管道两端阀室放空物理模型,开展管道放空的动态模拟分析,揭示了放空过程中主管道内低温现象的物理本征,探讨了地形起伏超临界CO2管道放空过程中的关键问题,特别关注了地形起伏对相态变化、低温风险及干冰生成的影响,提出了控制背压的安全放空方案。【结果】具有地形起伏超临界CO2管道放空应尽量避免在高压、低温下进行;需设计适宜的放空管径和开度,以规避低温脆断、干冰生成等风险;所提出的放空方案在具体地形条件下表现良好,能有效解决主管道放空过程中低洼地段的极致低温问题,并对放空出口的危害较小。【结论】研究成果为地形起伏地区超临界CO2管道的安全放空工艺设计与工程建设提供了理论支持,对工程实际应用具有参考价值,有助于保障CO2管道的安全高效输送。(图 11表5,参[27]
[Objective] Carbon capture, utilization and storage (CCUS) is essential for achieving carbon neutrality, in which the safety and efficiency of CO2 transmission plays a vital role. The pipeline transmission of CO2 in the supercritical phase has been widely applied internationally and China has basically mastered the rules to the process of supercritical CO2 pipelines steady-state transmission. However, further research is required to enhance understanding of the dynamic rules and safety risks associated with venting operations for supercritical CO2 pipelines with topographic relief. [Methods] Using OLGA, a physical model was developed for venting valve chambers at both ends of supercritical CO2 pipelines with topographic relief. A dynamic simulation analysis of pipeline venting was conducted, revealing the physical nature of the low-temperature phenomenon in the main pipeline during venting. Key issues in the venting process of the supercritical CO2 pipeline with topographic relief were discussed, focusing on the effects of topographic relief on phase transition, low-temperature risks, and dry ice formation. Finally, a safe venting scheme for backpressure control was suggested. [Results] The venting of supercritical CO2 pipelines with topographic relief should avoid high pressure and low temperatures as much as possible; appropriate venting pipe diameter and opening need to be designed to prevent risks such as low-temperature brittle fracture and dry ice formation; the suggested venting scheme was effective under specific terrain conditions, addressing extremely low temperatures in low-lying sections during main pipeline venting while minimizing harm at the venting outlet. [Conclusion] The research results offer theoretical backing for the safe venting process design and engineering construction of supercritical CO2 pipelines with topographic relief, holding practical value for engineering applications and contributing to ensuring the safe and efficient transmission of CO2 pipelines. (11 Figures, 5 Tables, 27 References)
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