Compressed air energy storage (CAES) plays a critical role in stabilizing power systems with high penetration of renewable sources by mitigating intermittency and supporting the achievement of “dual-carbon” objectives. The thermo-mechanical response and damage evolution of an underground lined CAES cavern under repeated operational cycles are investigated based on a 30 000 m³ demonstration project in Zhangbei County.
A coupled thermo-mechanical numerical model is developed using COMSOL Multiphysics, incorporating non-ideal thermodynamics of high-pressure air, a fracture energy-based damage model for concrete, the reinforcing effect of steel bars, and the mechanical behavior of the excavation damaged zone (EDZ).
Simulations are conducted under a typical operational cycle comprising 8 h charging, 4 h pressure maintenance, 4 h discharging, and 8 h maintenance. The results reveal significant temperature fluctuations inside the cavern (−30.68~70.18 ℃). Concrete cracking is found to initiate at a low internal pressure (~1.9 MPa) and evolve into circumferentially spaced cracks. Steel reinforcement effectively carries tensile stress at crack locations, demonstrating effective collaboration with concrete. The surrounding rock is shown to bear approximately 97.7% of the internal pressure, with its stiffness significantly affecting lining stress and cavern convergence. Increased EDZ stiffness is observed to improve load transfer and stability. Plastic zones are found to develop predominantly near the cavern crown and bottom during charging, exhibiting irreversible deformation.
The synergistic behavior of the steel-concrete-rock composite system is elucidated, providing a theoretical basis for the design and safety assessment of CAES caverns.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |