基于非稳态渗流过程的压气储能洞室空气渗漏率计算  

Calculation of air leakage rate in lined cavern for compressed air energy storage based on unsteady seepage process

作　　者：夏才初[1] 徐英俊 王辰霖 赵海鸥 薛小代[3] XIA Cai-chu;XU Ying-jun;WANG Chen-lin;ZHAO Hai-ou;XUE Xiao-dai(Department of Geotechnical Engineering,College of Civil Engineering,Tongji University,Shanghai 200092,China;Datong Qidi Future Energy Technology Group Co.Ltd,Datong,Shanxi 037000,China;State Key Laboratory of Control and Simulation of Power System and Generation Equipments,Department.of Electrical Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]同济大学土木工程学院地下建筑与工程系,上海200092 [2]大同启迪未来能源科技集团有限公司,山西大同037000 [3]清华大学电机系电力系统及发电设备控制和仿真国家重点实验室,北京100084

出　　处：《岩土力学》2021年第7期1765-1773,1793,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金面上项目(No.51778475);山西省科技厅重大专项(No.20201101019)。

摘　　要：为评估压缩空气储能洞室的密封性,基于多孔介质渗流力学理论推导了一种能考虑洞室空气渗漏过程和混凝土衬砌孔隙影响的压气储能洞室空气非稳态渗流方程,给出了计算洞室衬砌内空气压强分布的近似解析解。为精确求解此类非线性抛物型方程,通过有限差分法构造了一个无条件稳定的隐式差分格式,该格式具有二阶精度。进一步,对算例与现有计算结果进行对比,结果表明:与传统基于稳态径向渗流理论得到的空气渗漏估算公式相比,考虑空气非稳态渗流过程后计算得到空气渗漏量略微偏小;当混凝土衬砌渗透率小于6×10^(-20)m^(2)时,衬砌厚度为0.5 m的洞室在一个压缩空气储能循环下空气渗漏百分比小于1%,普通的抗渗混凝土均不能满足空气渗漏控制要求,需要采取特殊的密封措施;压气储能洞室的空气渗漏百分比与衬砌渗透率、储气压强、衬砌厚度等因素有关,渗透率越低、初始压强越大、衬砌厚度越大,空气渗漏百分比越小,衬砌厚度对空气渗漏的控制效果随着衬砌厚度的增大而减弱。To evaluate the air tightness of lined cavern for compressed air energy storage,a kind of unsteady seepage equation considering the influence of air leakage and porosity of concrete lining in the cavern is derived based on seepage flow theory of porous media,and an approximate analytical solution for approximate calculation of air pressure in the cavern is given.To solve this kind of nonlinear parabolic equation accurately,an unconditional stable implicit difference scheme with second order accuracy is constructed by using finite difference method.The results show that,compared with the traditional air leakage estimation formula based on the steady seepage theory,the air leakage calculated considering unsteady flow process of air is slightly smaller.When the permeability of concrete lining with a thickness of 0.5 m is less than 6×10^(-20)m^(2),the percentage of air leakage within 24 hours in a compressed air energy storage cycle is less than 1%,ordinary impermeable concrete cannot meet the requirements of air leakage control,and special sealing measures are thus needed.The air leakage percentage of compressed air energy storage cavern is related to lining permeability,air storage pressure,lining thickness.The lower the permeability is,the larger the gas storage pressure is,the larger the lining thickness is,the smaller the air leakage percentage is,and the control effect of lining thickness on gas leakage decreases with the increase of lining thickness.

关 键 词：压气储能 非稳态渗流 有限差分法 空气渗漏 

分 类 号：U453[建筑科学—桥梁与隧道工程]