Experimental investigation of factors affecting two-stage thermoelectric generator integrated with phase change materials

Abstract

In light of limitations in the performance of thermoelectric materials, this study proposes a two-stage thermoelectric generator (TEG) system integrated with phase change materials (PCMs). Three sets of experiments were designed to investigate the factors influencing the proposed TEG-PCM system. Two of them examined the effects of different heat sink configurations on the heat generated with and without paraffin wax as the PCM. The third experiment investigated the thermoelectric performance of the proposed system using a single-cavity heat sink with different PCMs. The results show that the heat source had a greater influence on the performance of the system than the thermal resistance of the heat sink. The PCM reduced the second-stage voltage, but it lasted for a long time. The configuration of the heat sink had a greater influence on the second-stage voltage (U2) than the first-stage voltage (U1). Although the mean value of U1 for the four-cavity configuration without PCM was slightly larger than that of the single-cavity configuration by 10 mV, the maximum value of U2 for the latter was larger than that of the former by 60 mV. The single-cavity configuration is thus more suitable for the two-stage TEG system. Under a 10 W power supply, the properties of different PCMs significantly influenced the duration of voltage in each stage while U1 was maintained at 600 mV. The results show that the factors considered here influenced the performance of the two-stage TEG-PCM system in the order of heat source > thermal resistance of the heat sink > type of PCM.