基于环绕式光纤的热风管温度解调技术

Temperature demodulation of hot air tube based on wrap-around optical fiber

为了克服分布式光纤及其温度传感技术应用于高炉热风管中所存在的距离漂移率高、光纤互换性差等缺陷,采用了双端单路解调法,对光纤始末两端所测得的Stokes和anti-Stokes光强度比做算术平均处理,来抵消光纤衰减项Zc。双端单路解调法的距离漂移率K=0.011,更换光纤产生的最大Raman比偏差为0.015。结果表明,该解调法的距离漂移率低,当要求更换其它光纤时,光纤衰减系数不需要重新标定,完全能够实现对沿光纤路径温度场信息的有效测量。

In order to overcome the following defects of high distance drift rate and poor optical fiber interchangeability whenthe distributed optical fiber and temperature sensing technology were used in blast furnace hot air tube, two terminal and singlechannel demodulation method （ TTSCDM） was proposed. The decay term Zc was offset after arithmetic average operation forStokes and anti-Stokes light intensity ratio from both directions. The distance drift rate K of TTSCDM was 0. 011 and themaximum Raman ratio deviation of replacing fiber was 0. 015. Experimental results show that this demodulation method has lowdistance drift rate. When optical fiber needs to be replaced, the decay coefficient does not need to recalibrate and the effectivemeasurement of temperature field along the optical path can be implemented.