Comparison of two different models for pile thermal response test interpretation
Comparison of two different models for pile thermal response test interpretation
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DOI：
10.1007/s11440-014-0306-3
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发表时间：
2014-02
期刊：
影响因子：
5.7
通讯作者：
F. Loveridge;W. Powrie;D. Nicholson
中科院分区：
文献类型：
--
作者：
F. Loveridge;W. Powrie;D. Nicholson
热响应测试（trt）通常用于表征钻孔热交换器的热阻，并评估周围地面的导热性。尽管国际指导建议trt应限制在152毫米（6英寸）的孔径内，但将相同的原位测试技术应用于桩式热交换器正变得越来越普遍。这种尺寸限制来自于大直径热交换器的热惯性增加，这使得传统线源分析技术解释测试数据所需的混凝土稳态假设无效。然而，考虑到桩混凝土的瞬态行为，最近发展了新的分析桩换热器的方法。本文将这些新方法应用于在小直径试桩上进行的多级TRT数据。然后将用该方法测定的导热系数和热阻与基于线源分析的传统分析方法进行比较。讨论了方法之间的差异，并观察到热阻在不同的测试阶段可能不是恒定的。
Thermal response tests (TRTs) are regularly used to characterise the thermal resistance of borehole heat exchangers and to assess the thermal conductivity of the surrounding ground. It is becoming common to apply the same in situ testing technique to pile heat exchangers, despite international guidance suggesting that TRTs should be limited to hole diameters of 152 mm (6 in.). This size restriction arises from the increased thermal inertia of larger diameter heat exchangers, which invalidates the assumption of a steady state within the concrete needed to interpret the test data by traditional line source analysis techniques. However, new methods of analysis for pile heat exchangers have recently been developed that take account of the transient behaviour of the pile concrete. This paper applies these new methods to data from a multi-stage TRT conducted on a small diameter test pile. The thermal conductivity and thermal resistance determined using this method are then compared with those from traditional analytical approaches based on a line source analysis. Differences between the approaches are discussed, along with the observation that the thermal resistance may not be constant over the different test stages.