能源隧道热响应试验数值分析与适用性评价

以能源桩和能源隧道为代表的能源地下结构是一类节能环保的地下结构形式,能源隧道的理论研究与实际应用还处于起步阶段,相关测试与设计方法还不够成熟。以新八达岭长城站能源隧道试验段为研究背景,利用COMSOL软件对能源隧道热响应试验进行了数值分析与适用性评价,对TPT测试工况进行了数值模拟,经验证与现场实测结果吻合较好;对线热源传热模型用于能源隧道TRT试验的适用条件与方法做了初步探索,利用相对热效率的概念对模拟结果进行了分析。结果表明,线热源传热模型不能直接用于分析能源隧道TRT试验结果,但是T_fln(t)曲线的斜率与模型输入的围岩导热系数线性相关,可定义相对热效率来反映围岩导热系数对隧道埋管换热器换热能力的影响。

Numerical Analysis and Applicability Evaluation of -Thermal Response Test in Energy Tunnels

Energy geostructure represented by energy piles and energy tunnels is a kind of energy-saving and environmentally-friendly underground structure. The theoretical research and practical application of energy tunnels are still in their beginning period, and the relevant testing and design methods are not mature enough. Taking the test section of the energy tunnel in the New Badaling Great Wall Station as a research background, the author used COMSOL to carry out numerical analysis and applicability evaluation of thermal response test(TRT) in energy tunnel. Thermal performance test(TPT) is also carried out to find agreement with field test results. The model was used to explore the applicable conditions of the line heat source model in tunnel TRT. The simulation results were analyzed by using the concept of relative thermal efficiency(eff-u). The results show that the line heat source transfer model cannot be directly used to analyze energy tunnel TRT results, but the slope of theT_fln(t) curve is linearly related to the input thermal conductivity of the surrounding rock. The relative thermal efficiency can be defined to reflect how thermal conductivity of the surrounding rock will affect the performance of the tube heat exchanger in tunnel.