压缩空气储能是关退煤矿地下空间资源具有广阔前景的规模化利用方式,但当前对高气压作用下煤矿软岩储气库复合结构受力和变形规律认识不清,严重制约了其发展。为此,研制了一套模拟煤矿软岩地下空间压气储能的大型模型试验系统,该模型试验系统主要由电液伺服大型真三轴加载平台、高压空气加载控制系统、储能硐室复合结构模拟系统及数据监测系统组成。其中,电液伺服大型真三轴加载平台用以模拟初始地应力;高气压加载控制系统由空气压缩机、高压气罐、控制系统、高压管路、压力阀和压力表等组成,用于精准控制充放气;基于相似理论,储能硐室复合结构模拟系统模拟软岩-配筋混凝土内衬-滑移层-密封层组成的复合结构;数据监测系统包括应变、压力和温度等传感器、光纤线缆及配套的数据采集分析仪器、软件,用于监测试验过程中关键参量的演化信息。针对曹庄煤矿压缩空气储能科研需求,开展了不同地应力组合、循环充放气及高压保持等工况下的模型试验。结果表明,该试验系统可以获得不同工况下压气储能硐室复合结构受力和变形规律,是开展进一步研究的有力工具。

Compressed Air Energy Storage (CAES) presents a promising and scalable approach for uti- lizing underground space resources in abandoned coal mines. However, the understanding of the stress and deformation behavior of the composite structure of gas storage cavern using coal mines under high pressure is deficient, which poses a significant barrier to its development. To address this issue, a large- scale model test system was developed to simulate the CAES in soft rock underground spaces of coal mines, the system which mainly consists of an electro-hydraulic servo controlled large-scale true triaxial loading platform, a high-air-pressure loading control system, a system for simulating the composite structure of a CAES chamber, and a data monitoring system. The electro-hydraulic servo controlled large-scale true triaxial loading platform is used to simulate the initial ground stress. The high-air- pressure loading control system is used for precise control of air charging and discharging, consisting of an air compressor, high-pressure air tank, control system, high-pressure pipeline, pressure valve, and pressure gauge, is used for precise regulation of air charging and discharging. Based on the similarity theory, the system for simulating the composite structure of a CAES chamber is, mimicks the composite structure composed of soft rock-reinforced concrete lining-slip layer-sealing layer. The data monitoring system includes sensors for strain, pressure, temperature, etc., optical fiber cables, and supporting data acquisition and analysis instruments and software to monitor the evolutions of key parameters during the test process. Model tests were conducted under different ground stress combinations, cyclic charging and discharging, and high-air-pressure holding conditions to meet the research needs of the Caozhuang coal mine CAES projects. The results show that the developed test system can obtain the stress and deforma- tion behavior of the composite structure of a CAES chamber under different working conditions, making it a powerful tool for further research.