摘要:
实时、准确地获取风速数据，有助于精准控制矿井风流。现有的热线式、叶轮式、超声波涡街式、差压式等矿用风速传感器或易受干扰，或无法检测微风速，或量程小，且均通过电信号获取风速，存在安全隐患。基于掺杂光纤光热转换特性和光纤Bragg光栅（FBG）测温原理，设计了一种矿用光纤热线式风速传感器，通过掺杂光纤将光能转换为热能，通过解调热交换下FBG中心波长漂移量推算传感探头温度变化，进一步计算出风速。在FBG解调过程中采用光栅复用技术，实现了多台传感器共用同一光源和解调仪，降低了成本。实验室测试结果表明：FBG中心波长漂移量与风速呈非线性关系；在较低的风速范围内，泵浦光源功率越高，FBG中心波长漂移范围越大，风速检测灵敏度越高，风速为0～0.57 m/s时，传感器灵敏度为1 370 pm/(m·s-1)，最高分辨率达0.7 mm/s；传感器响应时间随风速增大而减小，波长动态范围随之增大。现场测试结果表明：该传感器可实现煤矿井下微风速、低风速检测，稳定性较好，监测值能准确反映现场风速变化。
Abstract:
Real-time and accurate acquisition of wind speed data is helpful for precise control of mine wind flow. The existing mine wind speed sensors such as hot-wire type, impeller type, ultrasonic vortex street type and differential pressure type are either susceptible to interference, or unable to detect breeze, or small ranged. Moreover, all these sensors obtain wind speed through electrical signals, and there are safety risks. Based on the light-to-heat conversion characteristics of doped optical fiber and fiber Bragg grating(FBG) temperature measurement principle, a mine-used hot-wire-based optical fiber wind speed sensor is designed. The light energy is converted into heat energy through the doped fiber, and demodulating the amount of FBG center wavelength drift under heat exchange is used to calculate the temperature change of the sensor probe and the wind speed. In the FBG demodulation process, the grating multiplexing technology is applied to realize multiple sensors sharing the same light source and demodulator, which reduces the cost. Laboratory test results show that the FBG center wavelength drift is non-linearly related to wind speed. In the lower wind speed range, the higher the pump light source power, the greater the FBG center wavelength drift range, and the higher the wind speed detection sensitivity. When the wind speed is 0-0.57 m/s, the sensor sensitivity is 1 370 pm/(m·s-1), and the highest resolution is 0.7 mm/s. The response time of the sensor decreases with the increase of wind speed, and the wavelength dynamic range increases with the increase of wind speed. The field test results show that the sensor can realize the detection of breeze and low wind speed in coal mines with good stability, and the monitoring value can show the change of wind speed on site accurately.
百度学术
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