The water distribution systems in utility tunnel are considered as the lifeline projects. The leakage monitoring of water supply and drainage pipelines is closely related to the overall operation and safety of the utility tunnel. However, conventional pipeline leakage monitoring methods are difficult to realize the monitoring of ordinary temperature liquid and small leakage. Moreover, they also have problems with noise interference, high false alarm rate, and high cost. In order to overcome the shortcomings of the conventional methods, the evaporation‐enhanced Fiber Bragg Grating (FBG) temperature sensing (EETS‐FBG) method was proposed as a new type of leakage monitoring solution according to the principle of the psychrometer. This method utilizes the evaporative cooling characteristics of water‐absorbing porous materials and the FBG temperature sensors to realize leakage monitoring. On the basis of experiments, the feasibility of this method is explored, and the effects of wind speed, liquid temperature, and leakage volume on monitoring results are analyzed. The experimental results show that the EETS‐FBG method can monitor the temperature difference of 0.97–8.55°C in the humidity of 51.0–90.8%RH, and the measured values are in good agreement with the theoretical values, which shows that the method has good feasibility. In addition, the measured temperature difference increases with the ambient wind speed, while the leakage volume and water temperature have no obvious effect on the temperature difference, which shows that the method has good reliability and universal applicability. This method has outstanding advantages for normal temperature liquid and small leakage monitoring and is worthy of application and promotion.

中文翻译：

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基于蒸发增强的FBG温度传感技术的管道泄漏监测实验

公用事业隧道中的供水系统被视为生命线项目。供水和排水管道的泄漏监测与公用隧道的整体运行和安全性密切相关。但是，传统的管道泄漏监测方法难以实现对常温液体的监测，且泄漏量较小。而且，它们还具有噪声干扰，高误报率和高成本的问题。为了克服传统方法的不足，根据干湿计的原理，提出将蒸发增强的光纤布拉格光栅（FBG）温度感测（EETS-FBG）方法作为一种新型的泄漏监测解决方案。该方法利用了吸水多孔材料的蒸发冷却特性和FBG温度传感器来实现泄漏监测。在实验的基础上，探讨了该方法的可行性，并分析了风速，液体温度和泄漏量对监测结果的影响。实验结果表明，EETS-FBG方法可以在51.0–90.8％RH的湿度下监测0.97–8.55°C的温差，并且测量值与理论值吻合良好，表明该方法具有可行性好。另外，测得的温差随环境风速而增加，而泄漏量和水温对温差无明显影响，说明该方法具有良好的可靠性和通用性。该方法在常温液体中具有突出的优点，并且对泄漏的监测很小，值得推广应用。