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Abstract：
Raman-based distributed temperature sensing (DTS) is a valuable tool for field testing and validating heat transfer models in borehole heat exchanger (BHE) and ground source heat pump (GSHP) applications. However, temperature uncertainty is rarely reported in the literature. In this paper, a new calibration method was proposed for single-ended DTS configurations, along with a method to remove fictitious temperature drifts due to ambient air variations. The methods were implemented for a distributed thermal response test (DTRT) case study in an 800 m deep coaxial BHE. The results show that the calibration method and temperature drift correction are robust and give adequate results, with a temperature uncertainty increasing non-linearly from about 0.4 K near the surface to about 1.7 K at 800 m. The temperature uncertainty is dominated by the uncertainty in the calibrated parameters for depths larger than 200 m. The paper also offers insights into thermal features observed during the DTRT, including a heat flux inversion along the borehole depth and the slow temperature homogenization under circulation.
摘要：
基于拉曼的分布式温度传感（DTS）是在钻孔换热器（BHE）和地源热泵（GSHP）应用中现场测试和验证传热模型的宝贵工具。然而,温度不确定性在文献中很少报道。在本文中,针对单端DTS配置提出了一种新的校准方法，以及一种消除由于环境空气变化引起的虚拟温度漂移的方法。这些方法是在800m深的同轴BHE中进行分布式热响应测试（DTRT）案例研究的。结果表明，该校准方法和温度漂移校正具有鲁棒性，并给出了足够的结果。温度不确定性从地表附近的约0.4K非线性增加到800m处的约1.7K。温度不确定性由大于200m的深度的校准参数的不确定性主导。本文还提供了在DTRT期间观察到的热特征的见解，包括沿井眼深度的热通量反演和循环下的缓慢温度均质化。
