分布式光纤测温系统分辨率影响因素研究  

Factors influencing resolution of raman distributed temperature measurement system

作　　者：王泽润 叶志浩 夏益辉[1] 杨超 Wang Zerun;Ye Zhihao;Xia Yihui;Yang Chao(College of Electrical Engineering,Naval University of Engineering,PLA,Wuhan 430000,China)

机构地区：[1]中国人民解放军海军工程大学电气工程学院,武汉430000

出　　处：《仪器仪表学报》2021年第12期65-73,共9页Chinese Journal of Scientific Instrument

摘　　要：应用分布式光纤测温系统对船舶电力系统进行在线监测时,由于船舶电缆的特殊运行环境,对测温系统的空间分辨率和温度分辨率提出了更高的要求,而在基于拉曼散射双路解调的分布式光纤测温系统中,系统的空间分辨率、温度分辨率、时间分辨率和测温距离相互制约。为设计满足船舶电力系统在线监测需求的测温系统,分析了系统空间分辨率的影响因素,并在此基础上建立了基于光时域反射技术的分布式光纤测温系统的等效模型,分析了不同影响因素之间的主次关系;基于拉曼散射光强度公式推导出了准确性更高的系统温度分辨率影响模型;在此基础上得到了空间分辨率、温度分辨率、时间分辨率和测温距离之间的相互影响公式,为分布式光纤测温系统的性能指标设计提供了参考,在测温距离较短时,通过进一步增大累加次数和减小泵浦光脉宽,可在保证空间分辨率和时间分辨率的条件下提高空间分辨率。搭建实验平台对所提出的方法进行验证,通过调节累加次数和脉冲宽度在500 m的测温距离达到了温度分辨率0.65℃、空间分辨率1 m、时间分辨率1 s的分辨率指标。Due to the special operating environment of Marine cables,higher and higher spatial resolution and temperature resolution are required for existing distributed optical fiber temperature measurement systems.However,in the distributed optical fiber temperature measuring system based on Raman scattering demodulation,the spatial resolution,temperature resolution,temporal resolution and temperature measuring distance are mutually restricted.To design a temperature measuring system for meeting the on-line monitoring requirements of the ship power system,the influencing factors of the spatial resolution of the system are analyzed.On this basis,the equivalent model of distributed optical fiber temperature measurement system based on the optical time domain reflection technology is formulated,and the priority of each influencing factors is obtained.A more accurate influence model of system temperature resolution is deduced,which is based on the Raman scattering light intensity formula.Finally,the interaction formula among spatial resolution,temperature resolution,temporal resolution and temperature measurement distance is achieved,which provides a reference for the design of performance index of the distributed fiber temperature measurement system.By further increasing the accumulation times and decreasing the pulse width of pump light,the spatial resolution can be improved while ensuring the spatial resolution and temporal resolution in a short measurement distance.An experimental platform is established to evaluate the proposed method.By adjusting the accumulation times and pulse width in 500 m temperature distance,the temperature resolution is 0.65℃,the spatial resolution is 1 m,and the temporal resolution is 1 s.

关 键 词：分布式光纤测温 空间分辨率 温度分辨率 分辨率相互关系 

分 类 号：TH74[机械工程—光学工程]