Analysis of temperature control effect of composite phase change structure used in thermoelectric conversion system

•Experiments verify the feasibility of simulation calculation.•CPCM's thermal conductivity is better than PCM.•Heat storage and thermal conductivity must be considered simultaneously during temperature control.•The design of each set of CPCM is related to the location. In this study, phase change materials made using graphite foam (GF) are placed on the hot side of a thermoelectric generator for thermal control and additional energy output. The experiment results prove the feasibility of this method, and the simulation results indicate a balance between the thermal conductivity and the amount of heat absorption. Compared with GF of 50 W m−1 K−1, GF of 100 W m−1 K−1 can produce 47% more electricity, whereas GF of 200 W m−1 K−1 can produce 69% more electricity, but overheats within 54 s. Overheating will cause various problems and should therefore be avoid. A porosity of 0.9 can produce 71.81% more electricity than a porosity of 0.95, whereas a porosity of 0.8 can produce 114% more electricity, but the material overheats in 79 s. It can thus be predicted that the materials with a change in their composite phase should have a high thermal conductivity and sufficient volume for a temperature control of a thermoelectric generator.