Structural Design And Experimental Study Of Thermoelectric Conversion Device Based On Shape Memory Alloy Drive

Energy plays an important role in economic and social development in today's world.It is vital to economic prosperity,improvement of people's livelihood and national security.The consumption of energy will produce waste heat.The form of waste heat emission is complex and cannot be effectively used on a large scale.It not only causes waste of energy,but also is inconsistent with the current development needs of resource-saving and environment-friendly social development?In order to solve the problem of collecting waste heat generated by energy consumption,Nowadays,domestic and foreign countries have extensively studied smart materials to indirectly convert waste heat to generate electricity,forming a variety of secondary energy reuse technologies and methods.In this paper,based on the National Natural Science Foundation project "Research on Piezoelectric and Shape Memory Alloy Composite Thermal Energy Generation Technology and Methods",a device that combines the advantages of shape memory and piezoelectric materials for energy conversion is designed.The research contents of this paper are shown as follows:1.A mechanical structure using two kinds of intelligent materials to realize thermoelectric conversion is designed.The working mechanism of the thermoelectric conversion device: the deformation of the shape memory alloy is heated to drive the pulley group to continuously rotate,and during the rotation of the pulley group,the piezoelectric vibrator is deformed to generate electricity.2.The rotation of the impact wheel of the thermoelectric conversion device in this paper is analyzed.Firstly,analyze the reason why the shape memory alloy ribbon rotates two rounds from the perspective of force.Secondly,combined with the dynamic formula,calculate the impact force generated by the impact wheel during rotation,and determine the radius relationship that enables the two wheels to rotate.When the impact wheel radius is 30 mm,combined with the processing and assembly of the drive wheel,the radius range of the drive wheel is determined to be 12 mm <r <17mm and it is calculated that when the radius of the driving wheel is 13 mm,the impact force generated by the impact wheel is the largest,and its value is 0.1N.3.Based on the elastic theory of the material and the relationship between the stress and strain of the piezoelectric sheet,the theoretical model of the energy conversion of the piezoelectric cantilever beam under a given load in the thermoelectric conversion device of this paper is established.4.The ANSYS software was used to simulate and analyze the piezoelectric cantilever.Firstly,through static analysis,it is judged whether the maximum stress generated by the structure under the action of 0.1N exceeds the allowable stress of piezoelectric ceramics.Secondly,the modal analysis and harmonic response analysis are carried out on the piezoelectric cantilever under the condition that the structure is not damaged.Finally,the transient dynamic analysis of the piezoelectric cantilever beam is carried out,and the voltage variation curve of the piezoelectric cantilever beam with time is obtained.5.The experiment proves that the thermoelectric conversion structure designed in this paper can realize the conversion of thermal energy into electrical energy.Firstly,First,design an experimental scheme and build an experimental platform to conduct a driving experiment to verify that the driving device is feasible to convert thermal energy to mechanical energy.Secondly,The range of the center distance between two driving wheels with different driving wheel radii was studied.Finally,a thermoelectric conversion experiment is conducted to compare the impact distance between the impact tooth and the piezoelectric cantilever beam and the number of impact teeth on the voltage at the output of the piezoelectric cantilever.The experimental results show that when the diameter of the driving wheel is 30 mm,the center distance between the impact wheel and the driving wheel is 146 mm,the diameter of the shape memory alloy wire is 1mm,the meshing distance between the impact tooth and the piezoelectric cantilever beam is 4mm,the thickness of the impact tooth is 3mm,and the impact wheel with the number of impact teeth 6 continuously hit the piezoelectric cantilever beam,the instantaneous voltage generated is the largest,its value is 10.64 V.