真空低温环境下的光纤分布式测温方法

Optical Fiber Distributed Temperature Measuring Method under Vacuum Cryogenic Environment

传统的温度测量手段为点式测温,为解决真空环境下温度场分布测量存在的困难,基于激光在光纤中传播的拉曼散射效应和光时域反射技术,搭建分布式光纤拉曼测温系统,实现线式测温;根据空间环境设备内温度场的特点,研究了传感光纤的选用以及敷设方式、光纤穿罐法兰连接方式。通过在空间环境设备内长时间连续的温度测量,结果表明,分布式光纤拉曼测温系统能够长期工作在真空低温环境下,性能稳定,能反映出环境设备热沉上的温度分布状况,测量精度满足工程要求。

The traditional method of temperature measurement is point-temperature measurement.To solve the difficulties of measuring the temperature field distribution in vacuum environment,based on the Raman scattering effect and optical time domain reflection technology(OTDR)of laser propagation in optical fiber,a distributed fiber Raman temperature measurement system is built to realize line temperature measurement.According to the distribution characteristics of temperature field in vacuum cryogenic tank,the selection and laying mode of sensing fiber and the connection of optical fiber flange through the tank are also studied.The results show that the distributed fiber Raman tempreature measurement system can work in vacuum cryogenic environment for a long time,and the performance is proved to be stable.It can indicate the temperature distribution on heat sink,and the accuracy meets the engineering requirement.