一个新的压气储能多层预应力内衬洞室多目标优化模型

A new multi-objective optimization model of multi-layer prestressed lining cavern for compressed air energy storage

地下多层洞室是压气储能(CAES)工程的关键环节,其优化设计对提高压气储能工程的效率至关重要,而大多数压气储能工程的洞室优化模型只考虑强度指标,未考虑经济性指标。本文采用有限元方法模拟了高温高压作用下的CAES多层洞室,计算了各层的应力场和应变场(通过试验验证了εθ_(max)出现在衬砌层的顶部),并论证了衬砌层εθ_(max)受结构参数的影响较小,以及预应力衬砌的必要性。预应力衬砌洞室的数值计算结果表明,施加预应力可以有效地减小εθ_(max),提高CAES预应力衬砌洞室的稳定性。建立了一种新的CAES预应力内衬洞室的多目标优化模型,该模型考虑了安全性(最小化预应力以满足其强度条件)和经济性(最小化洞室表面积以降低施工成本)。计算结果表明,多目标优化模型比单目标优化模型(仅考虑强度指标)更安全、更经济地获得CAES多层洞室结构。

Underground multi-layer cavern is a key component in the compressed air energy storage(CAES)engineering and its optimal design is of vital importance for improving the CAES efficiency,while most of the optimization models for CAES cavern only have strength index without consideration of economical index.In this study,a finite element method of the CAES multi-layer cavern under high temperature and high pressure is used to calculate stress and strain fields of each layer(The_(max)imum circumferential strainεθ_(max)is experimentally verified to appear at top points of the lining layer)and to demonstrate the necessity of the prestressed lining sinceεθ_(max)of lining layer is little influenced by the structural parameters.Numerical results of the prestressed lining cavern indicate that the applied prestress can effectively decreaseεθ_(max)and improve the stability of CAES prestressed lining cavern.A new multi-objective optimization model of CAES prestressed lining cavern is established with consideration of safety(minimizing the prestress to satisfy its strength conditions)and economy(minimizing the cavern surface area to decrease the construction cost).Calculation results show that the multi-objective optimization model is superior to the single-objective optimization model(only strength index)since it can obtain a safer and more economical CAES multi-layer cavern structure.