基于田口法的隧道围岩蓄热系统性能优化及工程应用

Performance Optimization of Tunnel Surrounding Rock Heat Storage System Using Taguchi Design and Its Engineering Application

摘要:

不稳定可再生能源的大规模存储具有很大发展潜力。为此，提出隧道围岩蓄热型热泵系统并建立三维隧道围岩蓄热换热器耦合传热模型，同时，基于田口试验设计，提出了隧道围岩热泵系统蓄热性能优化方法，并应用于Stuttgart-Fasanenhof 能源隧道工程。在用现场热响应试验数据验证模型合理性的基础上，蓄热隧道的蓄热性能模拟结果表明，隧道围岩蓄热型热泵系统储热效能优于传统垂直钻孔埋管蓄热系统，且不需要高的前期钻孔成本和占地面积。建立4因子3水平下的L₁₀（3⁴）田口试验正交表，利用Minitab数据统计分析软件进行信噪比和方差分析，得出最优控制参数组合及各参数贡献率。工程应用结果表明：蓄热与取热温差的贡献率最高，依次为运行蓄取比、围岩初始温度、围岩导热系数；最优参数组合为围岩初始温度18 ℃，围岩导热系数1.5 W·m^-1·K^-1， 蓄取比1：2，蓄热与取热温差45 ℃。研究成果可为隧道围岩蓄热性能优化提供理论方法及技术支持。

Abstract:

The large-scale storage of unstable renewable energy has great potential. Therefore， a heat storage heat pump system for tunnel surrounding rock is proposed， and a 3D heat exchanger coupled model in tunnel surrounding rock is developed. Additionally， an optimization method for heat storage performance of tunnel surrounding rock heat pump system is proposed using Taguchi design， and applied to the Stuttgart-Fasanenhof energy tunnel project. The rationality of the model is well verified by on-site thermal response test data， and the simulation results of the heat storage performance of the thermal tunnel show that， the heat storage efficiency of the tunnel surrounding rock heat storage heat exchanger system is at least comparable to that of the traditional vertical borehole heat exchanger heat storage system， Moreover this system reduces the high borehole construction costs and minimizes the required underground area. Four operating parameters for the heat storage tunnel at three levels are assumed， and L₁₀（3⁴） orthogonal array is employed. The optimal control parameter combination and the contribution rate of each parameter are obtained by conducting signal-to-noise ratio and ANOVA analysis using Minitab statistical analysis software. The maximum percentage contribution is observed in factor D （heat storage and extraction temperature difference）， followed by the operating ratio， the initial temperature of the surrounding rock and the thermal conductivity of the surrounding rock， respectively. The optimal parameter combination is obtained， i.e.， the initial temperature of the surrounding rock is 18 °C， the thermal conductivity of the surrounding rock is 1.5 W·m^－1·K^－1， the operating ratio is 1：2， and the temperature difference between heat storage and extraction is 45 °C. The research results can provide theoretical methods and technical support for the optimization of heat storage performance of tunnel surrounding rock.