Abstract
Gas storage facilities are critical components of compressed air energy storage (CAES) power stations, and lined rock cavern gas storage facilities have attracted widespread industry attention due to their flexible siting and scalable capacity. Accurately determining the magnitude of internal pressure loads borne by each structural layer of lined rock cavern gas storage facilities is a prerequisite for safety assessment and structural design analysis. Based on elastoplastic theory for structural stress analysis, this study proposes a calculation method for the load sharing ratio of each structural layer in lined rock cavern gas storage facilities and verifies its accuracy. On this basis, the influences of sealing layer type, surrounding rock classification, lining structural configuration, lining reinforcement ratio, and maximum operating pressure on the internal pressure sharing ratio of each structural layer were investigated. The research results demonstrate that the surrounding rock is the primary component bearing the internal pressure load of underground gas storage facilities, with its load sharing ratio exceeding 90%. Variations in lining structural configuration, lining thickness, and operating pressure have relatively minor effects on the internal pressure sharing ratio, whereas factors such as sealing material type, surrounding rock classification, and lining reinforcement ratio exert relatively significant influences on the load sharing ratio of the lining and surrounding rock structural layers. Under the premise that the lining enters a plastic state, the presence of pre-set cracks in the lining has essentially no effect on the load sharing ratio, while increasing the lining reinforcement ratio can substantially increase the proportion of internal pressure borne by the lining. The research findings can provide theoretical support for the structural design and safety assessment of lined rock cavern gas storage facilities.
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Preamble
Study on Load Sharing Ratio of Internal Pressure in Lined Rock Cavern Gas Storage Structures
Zhang Yunlong¹,², Zheng Kexun¹,²*, Jiang Zhongming³, Zhou Wanfen³, Zou Shenwei¹,², Zhao Daiyao¹,²
¹PowerChina Guiyang Engineering Corporation Limited, Guiyang, Guizhou 550081, China
²China Hydropower Consulting Group Guiyang Survey and Design Institute Geotechnical Engineering Corporation Limited, Guiyang, Guizhou 550081, China
³School of Hydraulic and Ocean Engineering, Changsha University of Science & Technology, Changsha, Hunan 410114, China
Abstract
Lined rock cavern gas storage is a critical component of compressed air energy storage (CAES) power plants and has attracted widespread industry attention due to its flexible site selection and controllable scale. Accurate determination of the internal pressure loads borne by each structural layer of lined rock cavern gas storage is a prerequisite for safety evaluation and structural design analysis. This study proposes a calculation method for determining the load sharing ratio among structural layers of lined rock cavern gas storage based on elastoplastic theory for structural stress analysis and validates its accuracy. Building upon this foundation, the research investigates the influence of various factors on the internal pressure sharing ratio of each structural layer, including seal layer type, surrounding rock grade, lining structure configuration, lining reinforcement ratio, and maximum operating pressure.
The findings demonstrate that the surrounding rock mass serves as the primary load-bearing component of underground gas storage, with its load sharing ratio exceeding 90%. Variations in lining structure configuration, lining thickness, and operating pressure have relatively minor effects on the internal pressure sharing ratio. In contrast, factors such as seal material type, surrounding rock grade, and lining reinforcement ratio exert more significant influence on the load sharing ratio between the lining and rock mass. Provided the lining has entered a plastic state, the presence of pre-set cracks in the lining has essentially no effect on the load sharing ratio, while increasing the lining reinforcement ratio can substantially enhance the proportion of internal pressure borne by the lining. These research results provide theoretical support for the structural design and safety evaluation of lined rock cavern gas storage.
Keywords: compressed air energy storage; lined rock cavern gas storage; plastic deformation theory; sealing structure; load sharing