气体动载荷下压电振子能量转化特性实验研究

针对当前利用化学电池为传感器供能具有的使用时间短及污染环境等问题,提出了一种可应用于气动系统中气体动载荷环境的能量转化与收集装置。利用压电材料的正压电效应对压电振子发电机理进行分析,分析结果表明,在气体动载荷激励下输出电能与压力变化量呈正比。仿真分析了压电振子所在容腔的内部流场变化,并分析了腔内压力及压力变化量随时间的变化规律。结合理论研究与仿真分析设计并制作了一种压电振子能量转化实验样机,搭建了实验测试系统。以动态气体载荷为激励源对不同流量、周期及负载条件的改变进行了实验测试。实验结果表明随着距离的增加,压电振子的输出电压逐渐下降;随着流量的增加峰值电压增加,当周期为1. 2 s、流量为200 L/min、压力为0. 3 MPa时最大的输出电压为79. 60 V。

Experimental Research of Energy Transmission Characteristics for Piezoelectric Vibrator Induced by Dynamic Air Load

Chemical batteries have many shortcomings such as short service time and environmental pollution. A novel piezoelectric energy harvester which can be applied to gas dynamic load environment in pneumatic system is proposed. We analyze characteristics of piezoelectric energy harvester by using direct piezoelectric effect. The analysis result shows that output voltage is proportional to changing pressure value. The internal fluid field is simulated and the optimized position of piezoelectric patch is analyzed. The variation laws of pressure and pressure variation with time in the cavity are analyzed. According to theoretical and simulation analyses, a prototype of piezoelectric vibrator energy harvester is designed and a test system is built. We carry out an experiment to test the changes of different flow, cycle and load resistance conditions under high pressure air. The experiment results show that as distance increases, the output voltage of piezoelectric vibrator gradually decreases; the peak voltage increases with the increase of flow; the maximum output voltage is 79.60 V when the period is 1.2 s, the flow rate is 200 L/min and the pressure is 300 MPa.