地下水对CAES地下储气库气密性和围岩稳定性影响

Influences of groundwater on air tightness and surrounding rock stability of CAES underground gas reservoir

压缩空气储能(CAES)储气库密封和稳定是保证电站安全稳定运行的基础,储气库受力影响因素众多,且特性复杂,长期运行过程中气密性和稳定性的精准预测和评估一直是热点和难点。以考虑渗漏和传热过程的压缩空气热力学模型为非稳态边界、以热流固耦合理论为核心建立了储气库多物理场耦合下气密性和稳定性联合分析模型,探讨了洞周围岩中的地下水对储气库气密性和稳定性的影响。研究成果表明:(1)地下水的存在可使储气库每个循环气体损失量降低78%;(2)衬砌结构主要受拉应力作用,顶部和底部出现了应力集中现象,需进行加密配筋;(3)岩体中存在地下水有助于强化储气库内的气体密封效果。

The tightness and stability of compressed air energy storage(CAES)gas reservoir is the basis to ensure the safe operation of power station.There are many factors affecting the mechanics of gas reservoir and its mechanics characteristics are complex.The accurate prediction and evaluation of reliability and stability in the long-term operation process has always been an important topic.Based on the thermodynamic model for compressed air considering the leakage and heat transfer process as the unsteady boundary and the theory of thermo-hydro-mechanical coupling as the core,a joint analysis model for gas storage is established under the coupling of multiple physical fields.The influences of groundwater in the rocks around the cave on the air tightness and stability of gas storage are studied.The results show that:(1)The existence of groundwater can reduce the gas loss per cycle in gas storage by 78%.(2)The lining structure is mainly subjected to tensile stress,and the stress concentration appears at the top and bottom,where more steel bars is suggested to be configured.(3)The existence of groundwater in rock mass is helpful to strengthen the gas sealing effects in gas storage.