一种脱涡纵振式压电管道气流俘能器

A Pipe Airflows Piezoelectric Energy Harvester with Longitudinal Vibration Excited by Vortex Shedding

为满足管道流体监测系统的自供电需求,针对流速/向恒定、空间有限的管道流环境下压电振子的有效激励问题,提出一种脱涡纵振式压电管道气流俘能器。介绍了其系统构成及工作原理,并进行了理论和试验研究,证明了其结构原理的可行性。研究结果表明:平均阻力随流速/直径比增长呈二次方关系,平均阻力过大时会减小压电振子振幅,平均阻力系数随直径比上升先增加最终达到固定值(6.23);其他参数确定时,分别存在最佳流速和最佳直径比使输出电压最大,外接电阻为240 kΩ,流速为32 m/s,直径比为0.93时,试验测得最大输出功率为1.25 mW,应根据实际流速范围确定合理的直径比及负载以提高俘能器的输出功率,低流速时适当增大直径比、高流速时适当减小直径比有助于提高发电能力。

To meet the demands of pipe flows monitoring system for self-power and solve the problem of effective excitation of a piezoelectric vibrator in a flow-rate/direction constant and space-limited pipe flows environment, a novel pipe airflows piezoelectric energy harvester (PAPEH) with longitudinal vibration excited by vortex shedding is presented. Introduce the system composition and operational principle of the PAPEH, and carry out theoretical and experimental studies. The results show that the average drag has a quadratic relationship with flow rates and diameter ratios, and it reduces the amplitude of the piezoelectric vibrator when it is too large;The average drag factor increases with the diameter ratios and finally stabilize to 6.23;Other parameters are determined, respectively, there is the optimal flow rate and the optimal diameter ratio to maximize the output voltage, when the resistor is 240 kΩ, the flow rate is 32 m/s, the diameter ratio is 0.93, and the output power reaches 1.25 mW. Therefore, improving the output power should determine a reasonable diameter ratio and load based on the actual flow rates range. Proper increase the diameter ratio at low flow rates and reduction in diameter ratio at high flow rates help to increase power generation capacity.