光学 精密工程, 2014, 22 (8): 2001, 网络出版: 2014-09-15
光纤流量非浸入式测试系统
Non-intrusive optical fiber flow measuring system
光纤传感 光纤干涉仪 光纤光栅 流量测量 湍流振动 动态压力 optical fiber sensing optical fiber interferometer optical fiber grating flow measurement turbulent vibration dynamic pressure
摘要
提出了一种基于湍流振动原理的非浸入式流量测量方法。该方法通过在油管外壁缠绕特定长度的传感光纤,并在传感光纤两端焊接光纤光栅组成光纤流量传感单元。由于流体流过管壁时湍流产生动态压力,动态压力会导致缠绕在管壁上的传感光纤相位发生变化;通过光纤干涉仪技术、时分复用技术及相位载波调制解调技术解调出相位信息,即可实现流量的在线监测。实验数据分析显示,得到的相位变化与流速呈二次曲线关系,设计的实验系统可实现5~50 m3/h流量的实时在线测量。由于采用光纤作为传感器感知流量信号,该方法结构简单可靠,灵敏度高,避免了传感光纤流量计需要浸入流场的缺陷,是井下流量测试的理想方法。
Abstract
A non-intrusive flow test method based on turbulent vibration principle is proposed. The method wounds a specific length of sensing fiber tightly around the outer wall of a pipe and connects the optical fiber gratings at both ends,then the sensing fiber and the optical fiber gratings compose a flow sensing unit. When the fluid flows through the pipe, the dynamic pressure is generated by the turbulence, and the dynamic pressure causes the light phase shift of the sensing fiber to change. The phase information is demodulated by the fiber optic interferometer technology, time division multiplexing technology and phase generated carrier modulation and demodulation techniques, and the flow was detected in line. The experiments show the relationship between phase change and flow rate is a quadratic curve and the fluid flow monitoring range of the experimental system is from 5 m3/h to 50 m3/h. As the optical fiber is to be a flow sensing signal, the method is characterized by a simpler structure, higher sensitivity. It overcomes the shortcoming of an optical fiber sensing flowmeter in intrusive flow, and is an idea real-time monitoring method of flow for oil well logging.
尚盈, 刘小会, 王昌, 赵文安. 光纤流量非浸入式测试系统[J]. 光学 精密工程, 2014, 22(8): 2001. SHANG Ying, LIU Xiao-hui, WANG Chang, ZHAO Wen-an. Non-intrusive optical fiber flow measuring system[J]. Optics and Precision Engineering, 2014, 22(8): 2001.