基于分布式光纤传感技术的流速测量方法研究

Research on measuring method of flow velocity based on distributed optical fiber sensing technology

简要介绍了分布式光纤传感技术的流速测量方法的主要仪器设备。在研究加热光纤与流水之间传热过程的基础上,推导了流速与光纤稳定温升、加热功率等参数之间的基于分布式光纤传感技术的流速测量方法的理论方程。设计了模型试验,对不同流速与加热功率下,光纤温升情况进行了试验研究。在试验数据分析的基础上,研究了静水与流水中光纤温升情况,结果表明:所有温升曲线都可以分为上升和稳定两个阶段,流水中的光纤温升明显低于静水中的光纤温升,两者的差值随着功率及流速的不同而不同。加热功率越大,两者温差越大;流速越大,温差越大。研究了加热功率对静水中光纤温升的影响,通过分析发现:静水中的光纤稳定温升与加热功率之间存在着良好的线性关系。重点分析了在一定功率下,流速与光纤稳定温升之间的关系,结果表明光纤稳定温升与水流速度呈非直线的反比关系。最后,对该方法进行了讨论,提出了下一步研究建议。

The apparatuses of measuring method of flow velocity based on distributed optical fiber sensing technology are introduced briefly. By studying the heat-transfer process between optical fiber and running water, the theoretical equation of the method about flow velocity, stable temperature rise of optical fiber, heating power and other parameters is deduced. Model test is designed. And temperature rise tests of different flow velocity and heating power are carried out. Based on test data, temperature rise rules of still water and running water are compared. The results indicate： all curves of temperature rise compose of two stages, and the temperature rise in still water is higher than that in running water, and the temperature difference becomes greater with flow velocity and heating power. The effect of heating power on temperature rise of still water and running water is studied; and it is found that the stable temperature rise in still water has linear relationship with heating power. Stable temperature rise of optical fiber has nonlinear inverse relationship with flow velocity. At last, this method is discussed; and further study advice is put forward.