Evaluation of lining damage for hydrogen storage caverns: A cross-scale model

A critical challenge in the application of lined rock caverns (LRCs) for hydrogen storage is the absence of a suitable model to assess seal lining conditions. In this study, an innovative cross-scale model for LRC linings was developed. Based on the analysis of seal lining deformation induced by overall storage expansion, the model integrates the finite difference method and the discrete element method to comprehensively capture the interaction between concrete cracking and the seal lining. This approach enables the precise inversion of various complex damage states in the seal lining, including localized tensile deformation and indentation. The application of the model at the Daye hydrogen storage station revealed that the distribution pattern of mesoscopic cracks in the concrete lining is crucial for controlling the steel lining strain, with past oversights causing errors of more than 50%. Further investigations indicated that maintaining a seal lining thickness of more than 8 mm prevents the formation of wedge-shaped spalling blocks while mitigating their impact on the seal lining. Furthermore, increasing the ductility of the concrete increases the density of cracks. It reduces the maximum crack width and is identified as the most effective approach for lowering strain in the sealing lining. Finally, this study demonstrates that reducing the friction coefficient of the buffer lining leads to only a marginal reduction of up to 0.4% in the strain of the seal lining. This study offers valuable design insights for constructing similar LRC hydrogen storage systems and significantly enhances the accuracy of lining strain assessments, thereby serving as a powerful tool for optimizing parameters.