Experimental Investigation for a Novel Prototype of a Thermoelectric Power Generator With Heat Pipes

In order to obtain the power generation of the thermoelectric power generator (TEG) group, a similar structure of the disc sandwich structure and an experimental system are built to analyze the power generation performance and temperature characteristics. To improve heat transfer and move heat from the hot side to the cold side, heat pipes with high thermal conductivity are arranged on the adjacent cold and hot plates of the TEG. The similar sandwich structure has 17 cold plates and 17 hot plates for the TEG pieces, which are connected in series on the circuit. Working conditions are hot air flow and cold water flow; hot air temperature and cold water temperature are set to a fixed temperature. The power generation of a single TEG is tested for verifying linear changes in the power generation performance with temperature differences (Td). Experimental results are that the power generation is improved by the air flow and water flow increasing. The water flow has a smaller effect on the power generation than the air flow. In the cold side of TEG pieces, the temperature of the cold side showed a gradual upward trend, the temperature of the hot side showed a wave trough phenomenon, and the Td showed a wave trough phenomenon. The hot air flow and the cold water changing cannot weaken the temperature trend of the hot side and the cold side. The hot air flow can more significantly increase the Td than the cold water.

Analysis of Thermoelectric Energy Harvesting with Graphene Aerogel-Supported Form-Stable Phase Change Materials

Graphene aerogel-supported phase change material (PCM) composites sustain the initial solid state without any leakage problem when they are melted. The high portion of pure PCM in the composite can absorb or release a relatively large amount of heat during heating and cooling. In this study, these form-stable PCM composites were used to construct a thermoelectric power generator for collecting electrical energy under the external temperature change. The Seebeck effect and the temperature difference between the two sides of the thermal device were applied for thermoelectric energy harvesting. Two different PCM composites were used to collect the thermoelectric energy harvesting due to the different phase transition field in the heating and cooling processes. The graphene nano-platelet (GNP) filler was embedded to increase the thermal conductivities of PCM composites. Maximum output current was investigated by utilizing these two PCM composites with different GNP filler ratios. The thermoelectric energy harvesting efficiencies during heating and cooling were 62.26% and 39.96%, respectively. In addition, a finite element method (FEM) numerical analysis was conducted to model the output profiles.