多孔泡沫热电器件断裂及其对能量转化性能的影响规律研究

The thermoelectric generator could convert the waste heat into electricity and reduce carbon dioxide emissions. This meets the national development needs for energy conservation and emission reduction, and finally helps realize the carbon neutrality. The heat and electric conduction model was established to explain the internal mechanism of high output power of the porous thermoelectric foam. The effects of geometry and porosity on the fracture failure of the porous thermoelectric foam were also discussed. Then, the influential mechanism of fracture on the energy conversion performance of the porous thermoelectric foam was revealed. The results show that, the interfacial shear stress between the thermoelectric foam and the metal layer will decrease with the porosity. As long as an internal crack of the porous thermoelectric foam starts to extend, it will not stop until the device is completely broken. Moreover, the output power will first increase to the peak value and then decrease with the crack propagation. This is because the crack propagation indirectly raises the porosity of the thermoelectric foam and the contact area between the thermoelectric foam and the waste heat, and in turn promotes the output power of the thermoelectric device. With further crack propagation, both the thermal conductivity and the electrical conductivity of the thermoelectric foam will weaken, and the output power of the thermoelectric foam will decrease.