• Spectroscopy and Spectral Analysis
  • Vol. 40, Issue 11, 3425 (2020)
Wei-yi FENG1、1、*, Li-hua LIU1、1, Xu-ping ZHANG1、1, Xia ZHAO1、1, Xiao-wei HUANG1、1, and Chun-han YU1、1
Author Affiliations
  • 1[in Chinese]
  • 11. Fasten Group, Wuxi 214433, China
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    DOI: 10.3964/j.issn.1000-0593(2020)11-3425-05 Cite this Article
    Wei-yi FENG, Li-hua LIU, Xu-ping ZHANG, Xia ZHAO, Xiao-wei HUANG, Chun-han YU. Study on Leakage Detection Technology of Corrosive Acid Solution Based on Fiber Raman Temperature Measurement[J]. Spectroscopy and Spectral Analysis, 2020, 40(11): 3425 Copy Citation Text show less

    Abstract

    Distributed Temperature Sensing System (DTS) is based on the effect of Raman spectrum on temperature sensitivity. It can realize long-distance distributed temperature monitoring, especially suitable for fire alarm, high-temperature liquid leakage, low-temperature gas leakage and other application scenarios. However, for normal temperature media, such as highly corrosive solutions transported in chemical pipelines, when corrosion occurs in the pipeline infiltration, there is basically no temperature change between the leakage location and the surrounding environment. At this time, DTS temperature measurement technology is difficult to identify the occurrence of leakage events. In order to solve the problem of leakage detection of strong acid solution pipelines or tanks under normal temperature, in this paper, a technology based on optical fiber sensing to detect the leakage of acid solution medium was proposed. A novel self-sensing structure of acid solution was designed. Compared with leaking cable, it does not need to consume electricity and is not easy to cause a false alarm. Precise positioning and simple laying. Multi-point leakage detection can be realized across the pipeline. Fiber optic cable outer sheath material is alkali resistant and acid-resistant material, composed of nylon, magnesium hydroxide, aluminum hydroxide and a small number of colors masterbatch. It can be dissolved quickly by hydrochloric acid with the certain mass fraction. Exothermic chemical neutralization reaction occurs. Then the Raman spectrum of backscattering in the sensor fiber is changed, and the temperature of the sensor fiber can be increased by more than 5℃. The sensing fiber optic cable is connected to the DTS system, and the system adopts the dual demodulation method based on anti-stokes light and stokes light to calculate the temperature value of each position in the sensing fiber. Therefore, when the special optical cable and pipeline are laid in the same ditch, if acid solution leakage occurs in a certain position, resulting in the temperature rise of the point. After the dispersion compensation and the temperature calibration, the acid leakage event can be determined, according to the ratio change between the anti-stokes light and the stokes light. This technology not only solves the problem of engineering application of leakage detection and alarm in the transportation and storage of acid solution but also avoids the interference of false alarm of weak acid or alkali solution, saving energy and protecting the environment. It can accurately detect the leakage of the highly corrosive acid solution and improve the digital intelligent safety monitoring level of hazardous chemicals.
    Wei-yi FENG, Li-hua LIU, Xu-ping ZHANG, Xia ZHAO, Xiao-wei HUANG, Chun-han YU. Study on Leakage Detection Technology of Corrosive Acid Solution Based on Fiber Raman Temperature Measurement[J]. Spectroscopy and Spectral Analysis, 2020, 40(11): 3425
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