BTC方法应用于CO_(2)管道止裂韧性计算的可行性

Research progress of BTC method and feasibility of its application to calculate crack arrest toughness of CO_(2) pipeline

[目的]CCUS(Carbon Capture, Utilization and Storage)技术对实现“碳中和”战略目标具有至关重要的作用,而管道输送作为CCUS产业链的关键环节,面临的主要挑战之一是密相CO_(2)管道延性裂纹止裂问题。[方法]从裂纹止裂控制机理出发,深入调研了巴特尔双曲线(Battelle Two-Curve, BTC)方法的研究进展,并剖析了其应用于天然气管道止裂控制的技术现状及局限性。针对裂纹止裂韧性BTC修正方法,从夏比冲击吸收能量、落锤吸收能量及裂纹尖端张开角3个角度进行评述,根据密相CO_(2)的特性,探究了BTC方法应用于CO_(2)管道止裂韧性计算的可行性。[结果]借鉴应用于天然气管道止裂控制的BTC修正方法,基于管道裂纹动态延性扩展止裂设计判据中的速度判据,从驱动力与阻力两个方面,提出了BTC应用于CO_(2)管道裂纹止裂控制的修正方法。CO_(2)管道全尺寸爆破试验是目前确定密相CO_(2)管道止裂韧性最有效的方法,根据前人研究中CO_(2)管道全尺寸爆破试验数据,提出了BTC方法的修正系数范围,为CO_(2)管道的安全运行、CCUS技术的规模化应用提供了参考依据。[结论]利用BTC修正方法计算密相CO_(2)管道止裂韧性的研究尚处于起步阶段,虽然基于CO_(2)管道全尺寸爆破试验数据得到了BTC方法的修正系数,但可供参考的试验数据较少且适用范围有限,今后可以进一步结合数值模拟研究,提出更有效的修正方法。

[Objective]Carbon Capture,Utilization,and Storage(CCUS)technology has played a vital role in achieving the strategic goal of“carbon neutrality”.However,pipeline transmission,a critical component in the CCUS industry chain,is currently encountering challenges,particularly related to ductile crack arrest in dense-phase CO_(2) pipelines.[Methods]Drawing upon the crack arrest control mechanism,the research progress of the Battelle Two-Curve(BTC)method was thoroughly investigated to establish a foundation.A subsequent analysis was conducted to expose its technical standing and limitations in the application for controlling crack arrest in natural gas pipelines.Following this,the BTC correction method for crack arrest toughness was examined across three key factors:Charpy impact absorbed energy,drop weight absorbed energy,and crack tip opening angle.Taking into account the properties of dense-phase CO_(2),the feasibility of utilizing the BTC method to calculate the crack arrest toughness of CO_(2) pipelines was explored.[Results]Building on the BTC correction method for controlling crack arrest in natural gas pipelines,a new correction approach utilizing BTC was proposed for crack arrest control of CO_(2) pipelines.This method was developed from two perspectives:driving force and resistance,while incorporating the velocity criterion from the design criteria for crack arrest in dynamic ductile propagation.Through the examination of data from prior full-scale burst tests on CO_(2) pipelines,currently recognized as the most effective means for determining the crack arrest toughness of dense-phase CO_(2) pipelines,a correction coefficient range for the BTC method was established.This range serves as a benchmark for ensuring the safe operation of CO_(2)pipelines and promoting the broader adoption of CCUS technology.[Conclusion]The research on utilizing the BTC correction method to calculate the crack arrest toughness of dense-phase CO_(2) pipelines is still in its early stages of development.The correction coefficient for the BTC method derived from available full-scale burst test data of CO_(2) pipelines is inadequate,primarily due to the scarcity of experimental data and their limited application scope.Consequently,further research necessitates an integration with numerical simulation to develop more effective correction methods.