Abstract Knowledge of borehole heat exchanger efficiency is necessary to optimize the design and performance of ground source heat pump systems. To evaluate the heat transfer performance of the wildly-used vertical U-pipe BHE, a novel one-dimensional numerical model was developed to assess the thermal transfer performance of the BHE from short-term (thermal response test) to long-term (a heating period) for engineering application. The proposed numerical model took into account the internal capacity of the borehole and the thermal resistance between the two legs of U-pipe which are often negligible in traditional one-dimensional numerical models. A thermal response test data from a case at Vorbasse, Denmark and the data from the TRNSYS model were used to validate the feasibility and reliability of the presented model. Then, both a short-term thermal response and a long-term temperature development of the fluid in BHE and surrounding ground were simulated and analyzed based on the model. Additionally, this study did a sensitivity analysis to see what effect the parameters have on the BHE efficiency. Hereby the impact of given assumptions can be able to estimate and the results can serve for the optimum design and control of GSHP systems.

中文翻译：

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埋管式换热器传热性能的有效数值模型开发与分析

摘要 要优化地源热泵系统的设计和性能，必须了解埋管换热器的效率。为了评估广泛使用的垂直 U 形管 BHE 的传热性能，开发了一种新颖的一维数值模型来评估 BHE 从短期（热响应测试）到长期（a加热期）工程应用。所提出的数值模型考虑了钻孔的内部容量和 U 形管两条腿之间的热阻，这些在传统的一维数值模型中通常可以忽略不计。来自丹麦 Vorbasse 案例的热响应测试数据和来自 TRNSYS 模型的数据用于验证所提出模型的可行性和可靠性。然后，基于该模型对BHE和周围地层中流体的短期热响应和长期温度发展进行了模拟和分析。此外，本研究还进行了敏感性分析，以了解参数对 BHE 效率的影响。因此，可以估计给定假设的影响，结果可以用于地源热泵系统的优化设计和控制。