基于多峰高斯拟合的分布式拉曼测温系统设计与应用

针对温感区域长度小于空间分辨率导致温度测量不准确的问题,提出一种多点温度校正方案,并介绍了一种可应用于中小尺度剖面温度分布测量的装置和方法。采用基于多峰高斯拟合的方案,实现了多个测量不准确温度点的同时校正,提高了系统的温度准确度,设计了分布式拉曼测温系统样机,通过将光纤部分缠绕在PPR管上实现了中小尺度剖面温度分布测量。实验装置使2 m和1.5 m温感区域的测量准确度提高到1℃;测得冬季黄河万家寨水库冰盖厚度约为42.33 cm,与人工测量结果相差约为1.67 cm;测得36 m深河水剖面的温度约在0.32℃～0.90℃范围内波动。实验结果表明,采用该分布式拉曼测温系统能够在野外大范围监测河道流水剖面的温度分布。

Design and application of distributed Raman thermometry system based on multi-modal Gaussian fitting

Aiming at the problem that the length of the temperature sensing area is smaller than the spatial resolution, which leads to inaccurate temperature measurement, a multi-point temperature correction scheme was proposed, and a device and method that could be applied to the measurement of temperature distribution in medium and small scale sections were introduced. Using the scheme based on multi-modal Gaussian fitting, the simultaneous correction of multiple inaccurate temperature points was realized, and the temperature accuracy of the system was improved. A prototype of the distributed Raman thermometry system was designed, and the measurement of temperature distribution in medium and small scale sections was realized by wrapping the fiber around the PPR tube. The experimental device improved the measurement accuracy of 2 m and 1.5 m temperature sensing areas to 1 °C, the thickness of the ice sheet of the Wanjiazhai Reservoir on the Yellow River in winter was measured to be 42.33 cm, which was 1.67 cm different from the artificial measurement results, and the measured temperature of 36 m deep river water profile fluctuated in the range of 0.32 ℃ ~ 0.90 ℃. The experimental results show that the distributed Raman thermometry system can monitor the temperature distribution of the river flow profile on a large scale in the field.