Probabilistic Uncertainty Quantification of Borehole Thermal Resistance in Real-World Scenarios
Probabilistic Uncertainty Quantification of Borehole Thermal Resistance in Real-World Scenarios
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DOI：
10.2139/ssrn.3901841
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发表时间：
2021-08
期刊：
影响因子：
--
通讯作者：
W. Choi;H. Kikumoto;R. Ooka
中科院分区：
文献类型：
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作者：
W. Choi;H. Kikumoto;R. Ooka
埋管换热器 (BHE) 的热阻根据管腿位置的不同而显着变化。然而，由于BHE极其细长，在施工过程中无法完全控制管道位置。因此，从一个 BHE 估算的井眼热阻 (Rb) 不能代表整个井场。本研究通过蒙特卡罗模拟对Rb固有的不确定性特征引起的不确定性进行概率量化。考虑了以下四种情况：1) 管腿沿钻孔的中心轴移动，2) 使用垫片插入 U 形管以保持柄间距，3) 管腿自由位于钻孔内，4) 考虑管道位置、钻孔半径以及灌浆和地面的热导率的不确定性。结果表明，间隔物的使用显着提高了 Rb 并降低了其不确定性范围。最后一种情况的结果表明，最大 Rb 可能是最小值的两倍以上。此外，系统分析了 Rb 根据管道位置的空间变化，以阐明 b 变化的动态。结果表明，通过热响应测试获得的 Rb 不能充分代表整个井场。
The thermal resistance of a borehole heat exchanger (BHE) varies significantly depending on the position of the pipe legs. However, the pipe position cannot be fully controlled during its construction because of extreme slenderness of BHEs. As a result, the borehole thermal resistance (Rb) estimated from one BHE cannot represent the entire borefield. This study probabilistically quantified the uncertainty of Rb caused by the inherent uncertain characteristics through Monte Carlo simulations. The following four scenarios were considered: 1) pipe legs move along the central axis of the borehole, 2) insertion of a U-tube using spacers to maintain the shank spacing, 3) pipe legs freely located inside the borehole, and 4) considering uncertainty of the pipe location, borehole radius, and thermal conductivities of the grout and ground. The results demonstrated that the use of spacers significantly improves Rb and reduces its uncertainty range. The results of the last scenario revealed that the maximum Rb could be more than twice the minimum value. Moreover, the spatial variation of Rb according to the pipe position was systematically analyzed to clarify the dynamics of b change. The results suggest that Rb obtained through a thermal response test cannot adequately represent the entire borefield.