Existing thermal management schemes struggle to actively and efficiently create a low-temperature heat sink in a limited enclosed space. Hence, a composite thermoelectric refrigeration thermal management system based on flat heat pipes is proposed in this study. A numerical simulation model of the composite system was developed, and an experimental platform for the composite thermoelectric refrigeration thermal management system was established to verify the accuracy of the model. The results showed that the proposed composite thermal management system provided a low-temperature heat sink for the entire thermal management system in a limited space and solved the problem of heat accumulation at the hot end of the thermoelectric refrigeration module by coupling with the plate heat pipe. The thermoelectric refrigeration system based on a flat-plate heat pipe was considerably better than that based on aluminum fins in terms of 1-12 A working current. The cooling capacity and COP (coefficient of performance) of a single thermoelectric module plate were effectively increased by 38.35% and 14.81%, respectively, under the best working conditions.

Phase change heat transfer devices like heat pipes are widely utilized in temperature control and heat transfer. However, the traditional single uniform wick makes it hard to meet the requirements of capillary pressure and permeability for high-performance heat pipes, thus limiting the improvement of heat transfer performance. In this paper, a gradient structure wick sintered by 316 L stainless steel powder is designed. The capillary performance is tested and characterized through permeability test experiments and capillary rise infrared test experiments. Moreover, the influence of different particle sizes of sintered powder on the capillary performance of the wick structure is studied. The experimental results indicate that the capillary pressure and permeability of the gradient structure wick are significantly improved compared with the traditional single structure wick. Its capillary performance parameter S (K $\cdot$∆Pcap) is enhanced by more than 30%, providing an effective alternative for the wick of two-phase heat exchange devices.