Active cooling performance of a PCM-based thermoelectric device: Dynamic characteristics and parametric investigations

Phase change materials (PCM) are widely seen as a cooling medium in thermoelectric systems capable of effectively reducing the hot end temperature of thermoelectric device and improving energy conversion efficiency. In this study, a comprehensive numerical model is developed to investigate the active cooling performance of a PCM-based thermoelectric device where the phase-change dynamics and thermo-electric conversion physics take place simultaneously. The dynamic changes of key parameters, such as hot and cold end temperatures of thermoelectric device, liquid fraction of PCM over time under typical operating conditions are simulated to better understand the dynamic characteristics of the PCM-based thermoelectric device. The thermoelectric operating current, cooling load, component height ratio and PCM melting temperature have been parametrically swept to evaluate their effects on the system's cooling performance. And then a comparison analysis on active cooling potential of thermoelectric de -vice with and without PCM is performed in terms of the energy and exergy efficiencies. Furthermore, temperature distribution and cooling region of PCM-based thermoelectric device are sensitively deter-mined to better reveal their dynamic matching mechanism. Numerical results demonstrated that the cooling time of the PCM-based thermoelectric device has been obviously extended due to the constant maintenance in the cold end temperature of thermoelectric device during phase change period. The energy and exergy efficiencies of the PCM-based thermoelectric device are found to be 30.08%, 402.08% greater, respectively, than that of the thermoelectric device without PCM when the time is 20 s. Present research could be beneficial for cooling performance improvement of the thermoelectric-phase change coupling processes. (c) 2022 Elsevier Ltd. All rights reserved.