Study On Wideband Piezoelectric-triboelectric Hybridized Energy Harvester For Fluid Pipelines

With the development of wireless communication technology,wireless sensor networks(WSN)are widely used in fields such as long-distance pipeline integrity monitoring and river water quality monitoring.Traditional WSN nodes are powered by batteries,which have drawbacks such as short lifespan,large size,the need for regular battery replacement,and difficulty in recycling,disposal,and environmental pollution,which cannot meet the sustained power supply needs of WSNs.To address this problem,a viable solution is to replace the traditional battery power supply with an energy harvester that can collect mechanical,solar,wave,and thermal energy from the environment and convert it into electrical energy.Piezoelectric vibration energy harvesters have the advantages of high energy density,low cost,ease of miniaturization,and flexible structural design,making them particularly suitable for powering WSN devices.However,a single piezoelectric vibration energy harvesting method has many drawbacks in practical applications,such as low energy conversion efficiency,narrow working frequency band,and limited applicability to pipeline applications.Therefore,developing a composite device to collect vibration energy is an effective way to improve the energy harvesting efficiency of piezoelectric vibration energy harvesters.By integrating two or more energy harvesting methods,the advantages of each method can be synergized while compensating for the shortcomings of piezoelectric vibration energy harvesters,better meeting the power supply needs of WSNs.Therefore,this paper designs a wideband piezoelectric-friction composite flow-induced vibration energy harvester for fluid transport pipelines and studies its output performance.The main work of this paper is as follows:(1)Firstly,the paper analyzes the domestic and foreign research status of wideband piezoelectric vibration energy harvesters,composite piezoelectric vibration energy harvesters,and flow-induced vibration energy harvesters,analyzes the advantages and disadvantages of energy harvesters with different types of structures,proposes a new structure of a right-angled trapezoidal cantilever beam,and determines the plan to use a piezoelectric-friction composite energy harvester.(2)Theoretical models of piezoelectric energy harvesters,friction-based nanogenerators,and fluid-structure coupling are established,and the main factors affecting the output performance of the devices are analyzed based on the theoretical models.Combining theoretical analysis with COMSOL finite element simulation software,the structural dimension design optimization of the wideband piezoelectric cantilever beam array vibration energy harvester and the flow-induced vibration piezoelectric-friction composite energy harvester are respectively completed.(3)The paper completed the device fabrication and assembly,studied the testing methods of the device,built the testing platform of the device,and completed the device testing and analysis.The experimental results showed that the frequency bandwidth of the wideband piezoelectric cantilever array vibration energy harvester was about 15.25Hz.At a wind speed of 21 m/s,the output power reached a maximum of 98.981m W and the power density was 154.9m W/cm~3 with the best external load resistance and mass load.The flow-induced vibration piezoelectric-friction hybrid energy harvester achieved maximum output power at a wind speed of 15m/s with the best external load resistance and mass load,and the output power of the piezoelectric unit was 169.52m W,the output power of the friction unit was 22.44m W,and the hybrid output power was 191.96m W.Within the wind speed range of 3 to 21 m/s,the output power of the wideband piezoelectric cantilever array vibration energy harvester increased linearly from3.722m W to 98.981m W,while the output power of the flow-induced vibration piezoelectric-friction hybrid energy harvester fluctuated within the range of 121m W to214.4m W.Compared with the wideband piezoelectric cantilever array vibration energy harvester,the output power of the wideband piezoelectric cantilever array vibration energy harvester has been maintained at a higher level,and it is less affected by the change of wind speed.The simulation,and experimental results above have verified the high energy harvesting efficiency of the designed flow-induced vibration piezoelectric-friction hybrid energy harvester,providing an effective solution for wireless network node energy supply in pipeline inspection.