A novel optimization method for thermoelectric module used in waste heat recovery

When recycling fluid waste heat with thermoelectric devices, the current generated by the thermoelectric module is limited by the minimum current among the thermoelectric legs, which results in electric power losses. To address this issue, a novel optimization method for thermoelectric module structures is first proposed, wherein the length of the thermoelectric legs is determined by their specific temperature differences. Additionally, a fluid-thermal-electric multiphysics model is developed to predict the behaviour of an air-to-water thermoelectric generator system. To reduce the workload, a simplified thermoelectric module is used to conduct the optimization. The results indicate that the fluid-thermal-electric multiphysics model can determine the temperature distributions and voltage distributions of the thermoelectric generator system with acceptable accuracy. The proposed optimization method can effectively improve the output performance of the thermoelectric module. Despite using the same amount of thermoelectric materials, the novel thermoelectric module exhibits a higher output power than the base thermoelectric module structure when Delta l <= 0.03 mm, and the optimal value of Delta l is approximately 0.01 mm for the simplified thermoelectric module. In addition, if the thermoelectric module contains a greater number of thermoelectric legs, the optimization method will provide greater performance enhancements. The proposed optimization method contributes to enhancing the output performance of thermoelectric modules used for fluid waste heat recovery.