Analysis Model of Crack Arrest for Supercritical CO₂ Pipelines Containing Impurities

School of Mechanical Engineering, Xi’an Shiyou University, 710065, Xi’an, Shaanxi, China

^* Corresponding author’s email: bchen@xsyu.edu.cn

Abstract

CO₂ transport pipelines, as a critical link in CCUS technology, are more prone to fracture propagation under the effects of environment and high pressure due to the special characteristics of CO₂, resulting in ductile fracture incidents. However, the commonly used original Batelle two curves method (BTCM) has large errors applied to CO₂ pipelines containing impurities. In this paper, a corrected BTCM based on a hoop stress calibration factor was proposed to evaluate the crack arrest ability of CO₂ pipelines. The reliability of the modified model was verified based on the experiments data. The results show that the GERG-2008 equation of state is more suitable in predication of decompression wave velocity, and fracture propagation velocity model with a correction factor of c_cf =2.0 was verified in quite good agreement with experiment results. This corrected BTCM that can be directly applied to engineering, provided theoretical basis and suggestions in the design and safe operation of CO₂ pipelines containing impurities.