Experimental analysis of the dynamic performance of a phase change material-thermoelectric generator system

Abstract

Coupling phase change materials (PCMs) with thermoelectric generators (TEGs) can mitigate the instability in output performance caused by fluctuations in heat sources. In this study, an experimental test system for PCM-TEG was established, and erythritol was selected as the phase change material. The impact of dynamic heat source parameters on the key performance parameters of the PCM-TEG system was investigated. The results indicate that compared with traditional thermoelectric generation systems (TTEGs), the PCM-TEG system reduced the hot end temperature by 48.6 °C, effectively preventing TEG from overheating damage. The maximum output voltage of the PCM-TEG system was only 85% of the TTEGs, but the operating time was extended by 43.1% compared with the TTEGs. At heat source powers of 40 W and 60 W, the PCM was unable to undergo phase transition, which was unfavorable for heat storage. Both the maximum output power and average efficiency of the system increased with the rise in heat source power. A longer heating time led to higher temperatures during the PCM heating phase, resulting in higher maximum output power. Increasing the heating time from 6000 s to 12,000 s led to a 47.1% enhancement in the maximum output power. Moreover, prolonging the heating time could extend the operating time of the high-voltage stage, albeit with minimal impact on the output performance during the PCM heat release phase.