The Institute of Precision Machinery and Smart Structure, College of Engineering, Zhejiang Normal University, Yinbin Street 688, Jinhua 321004, China.
Key Laboratory of Intelligent Operation and Maintenance Technology & Equipment for Urban Rail Transit of Zhejiang Province, Zhejiang Normal University, Yinbin Street 688, Jinhua 321004, China.
Sensors (Basel). 2022 Jun 26;22(13):4832. doi: 10.3390/s22134832.
Air velocity of coal mine ventilation is an important consideration that may cause serious damage. This paper proposes a simple, low cost and effective air velocity monitor (AVM) for coal mine ventilation. The AVM uses the lock-in characteristic of vortex-induced vibration (VIV) to sense the air velocity. Amplitude of the VIV is converted into frequency signal of a vortex-induced triboelectric nanogenerator (VI-TENG) to improve the durability. Structure of the AVM are designed, and parameters of the AVM are optimized with experiments. For the upper and lower air velocity thresholds of 3.1 and 3.6 m/s, the optimized flexible beam length, slider weight, electrode space and electrode width are 42.5 mm, 0.4 g, 0.2 mm and 0.5 mm, respectively. Experiments also show that the output frequency of the VI-TENG could represent the amplitude of VIV well with the correlation coefficient of 0.93. Durability test demonstrates that the AVM generates stable output frequency in 120,000 cycles. A prototype and its controller are fabricated. Wind tunnel tests of this prototype show that it can give alarm when the gas velocity goes above the upper threshold or below the lower threshold. The proposed AVM could be a good solution for simple and effective coal mine ventilation alarm.
煤矿通风风速是一个重要的考虑因素，可能会造成严重的破坏。本文提出了一种简单、低成本、有效的煤矿通风风速监测器（AVM）。AVM 利用涡激振动（VIV）的锁定特性来感知风速。VIV 的幅度被转换为涡激摩擦电纳米发电机（VI-TENG）的频率信号，以提高耐久性。设计了 AVM 的结构，并通过实验对 AVM 的参数进行了优化。对于 3.1 和 3.6 m/s 的上下风速阈值，优化后的柔性梁长度、滑块重量、电极间距和电极宽度分别为 42.5 mm、0.4 g、0.2 mm 和 0.5 mm。实验还表明，VI-TENG 的输出频率与 VIV 的幅度具有良好的相关性，相关系数为 0.93。耐久性测试表明，AVM 在 120,000 个循环中产生稳定的输出频率。制作了一个原型及其控制器。该原型的风洞试验表明，当风速超过上限阈值或低于下限阈值时，它可以发出警报。所提出的 AVM 可为简单有效的煤矿通风报警提供一个很好的解决方案。
