压气储能电站地下储气库围岩多场耦合损伤特性及稳定性研究

Granitic formation is one of the ideal formations for compressed air energy storage(CAES) repository in China. Indoor experiments, theory study and numerical method are employed for the analysis of the muti-fields coupling responses and stability of the underground chambers of CAES plant during operation period. Firstly,the characteristics of heat exchange between granite and compressed air and the feature of damage evolution of granite under the cyclic temperature and stress loads are studied by experiment method. The heat transfer mechanism due to gas seepage and damage evolution law of granite due to muti-cyclic loads action is expected to be revealed. Secondly, a damage model with non-isothermal non-Darcy seepage stress coupling effect is expected to be constructed. And the dynamic thermal-mechanical boundary condition of the coupling model is also intended to be founded. In the end,based on the solution scheme of combination programming technology for the analysis of coupled thermo-dydro-mechanical damage,through the numerical simulation analysis, the muti-fields coupling response feature and the variation law of stability of the underground chamber are hopeful to be discovered. The generation conditions and controlling methods of negative temperature of the compressed air in repository are also expected to be obtained. The research achievements could provide a support of theory and technology for the construction and operation of the large scale underground chamber for compressed air storage in CAES plant. Therefore this study will be of great scientific significant and have the engineering application value.

花岗岩地层是压气储能(CAES)电站地下储气库的理想候选地层之一。本课题拟针对CAES电站运行状态下的地下储气库围岩多场耦合损伤特性及稳定性等科学问题，首先，开展花岗岩对流换热特性和温度应力同步循环作用下的耦合损伤演化特性试验研究，揭示花岗岩气渗条件下的渗流传热机理及多重循环荷载作用下的累积损伤演化规律；然后，基于试验成果和多孔介质力学理论，构建循环荷载作用下裂隙花岗岩的非等温非达西渗流应力耦合损伤模型以及储气库的动态热-力学边界数学模型；最后，在解决岩体非线性热流固耦合损伤数值分析的混合编程关键技术基础上，利用数值仿真手段，揭示不同运行工况下地下储气库围岩的多场耦合损伤特性及稳定性变化规律，并获得储气库内压缩空气的负温形成条件与围岩负温控制方法。研究成果可为CAES电站大规模地下储气库建设与运行提供理论和技术支持，具有重要的科学意义和工程应用价值。

兴建大规模压缩空气蓄能电站是解决新能源电力不稳定性的有效途径之一。浅埋地下岩穴储气库建造技术是我国大范围推广压缩空气储能电站的关键技术之一。本项目针对大规模压缩空气储能电站在运行状态下地下储气库围岩多场耦合损伤特性及稳定性等方面的科学问题，采用室内和现场试验研究以及理论分析方法进行全面系统研究。首先，研究了地下储气库围岩温压同步损伤特性及渗流传热特性测试的试验装置，在此基础上，测试了花岗岩的渗流传热性能指标及温压同步损伤力学与气渗性能参数，获得了花岗岩的对流换热和温度应力同步循环作用下的耦合损伤演化规律。其次，推导了考虑湿度及压缩因子变化的储气库内压缩空气热力学过程分析模型，并结合现场试验成果研究了地下储气库热力学特性变化规律，首次揭示了地下储气库温度与湿度时空分布演化规律。第三，基于试验及文献研究成果，构建了频繁循环荷载作用下裂隙花岗岩非等温非达西渗流应力累积损伤耦合模型，建立了储气库的动态热-力学边界数学模型，开发了基于热不平衡理论的裂隙岩体多场耦合损伤分析数值程序。第四，采用数值模拟方法，揭示了花岗岩气渗条件下的渗流传热机理以及储气内压缩空气能量转换机理，获得了地下储气库围岩的多场耦合损伤特性及稳定性变化规律。最后，提出了储气库内压缩空气的负温形成条件与围岩负温控制方法。研究成果可为CAES电站大规模地下储气库设计与运行提供理论依据和技术支持。