| With the development of intelligent drilling technology,a large number of sensors are required to monitor the temperature,pressure,vibration,depth,acceleration and other information during the drilling.However,the complex and harsh drilling conditions bring great challenges to the deployment and energy supply of sensors,and it is urgent to develop environmental energy capture technology to realize the self-supply of energy for drill pipe sensors.As an emerging energy harvesting technology,triboelectric nanogenerators can efficiently convert weak mechanical motion into electrical energy,which has attracted extensive attention at home and abroad.To this end,this thesis innovatively proposes a Cantilever Beam-Based Triboelectric Nanogenerator(CB-TENG)embedded inside the drill pipe to collect the vibration energy of the drill pipe to realize the sensor and power supply.The structure of CB-TENG designed in this thesis consists of double vibrators and crossinclined aluminum electrodes,where the vibrators consist of spring steel and a polytetrafluoroethylene(PTFE)dielectric flexible film attached to its surface.The vibrator is alternately contacted and separated from the aluminum electrode under the periodic excitation of the vibration source,the built-in electric field of the two dielectric layers is constantly changing,and the electrons are driven to flow in the external circuit,thereby generating electrical output.In order to obtain high-performance CB-TENGs,the effects of structural parameters,vibration conditions,and number of array elements on the output performance of CB-TENGs are investigated.(1)The structural parameters of the research on this thesis include the backplane structure,the number of vibrations and the thickness of the spring steel.The CB-TENG with a cross-plate structure has better output than the parallel-plate,and the transfer charge and the opening voltage are increased by double vibrators and 1.55 times,respectively.The output performance of the twins is better than that of monocular,and the maximum opening voltage has increased by 2.86 times.The effect of spring steel on the output of CB-TENG shows the trend of increased first and then decreased,and the peak output is obtained when the thickness is 0.12 mm.(2)Explore the output characteristics of CB-TENG in different vibration frequencies,vibration amplitude and vibration orientation angle.Electric output shows a synchronous growth trend with the growth of vibration frequency and vibration.However,with the increase of the corner of the vibration,the electric output shows attenuation,and at the same time,the electric output becomes unstable.(3)The CB-TENG circle array structure is designed to match the structural characteristics of the drill pipe,and the output characteristics of the array are studied.With the increase of the number of parallel units,the open-circuit voltage basically does not change;the short-circuit current shows a linear increase,from 10 μA to 49.85 μA,an increase of 3.985 times;Loading index decreases,from 160MΩ to 16MΩ.At the same time,CB-TENG shows a good robustness,which can be used as a small sensor and LED lights as a power supply.In summary,the CB-TENG studied in this thesis can effectively harvest energy in the drill pipe vibration on the basis of adapting the drill pipe size.It is expected to become a new type of underground power supply method,as a supplementary method or combined with existing power supply methods to promote the development of smart drilling technology. |
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