Next generation flat-plate oscillating heat pipes characterized by topological channel layouts applicable for multi-heat source cooling

Abstract

To meet the multi-heat source cooling requirement for electronic devices, novel flat plate oscillating heat pipes (FPOHPs) with topological channel layouts were developed and experimentally tested. The topological channels were fabricated via the chemical etching technique accompanied by micro-grooved structures at heated regions for promoting bubble generation and growth. The startup behaviors and heat transfer performance of topological FPOHPs (TO-FTOHPs) were evaluated and compared with conventional FPOHPs (CO-FPOHPs) under dual and triple heat source heating conditions. Refrigerant R141b was used as the working fluid at volumetric filling ratios ranging from 30 %-60 %. Compared to CO-FPOHPs, TO-FTOHPs could match with multi-heat source cooling featured by lower startup temperatures, smaller temperature fluctuations, and higher temperature uniformities and heat transport capabilities. For the dual heat source cooling condition, the effective thermal conductivity (ETC) of TO-FPOHP is about 1245 W/(m·K) at the combined condition of 70 W power input and 50 % filling ratio, 38 % higher than CO-FPOHP. Furthermore, the average temperature at two heated regions could be reduced by 16.7 °C for the TO-FPOHP as compared with the CO-FPOHP under the dual heat source condition of 30W-30 W power input. For triple heat sources, an ETC of 1655 W/(m•K) was achieved at the filling ratio of 50 % with respect to a maximum heat transport capability of 180 W, and its ETC is about 11.3 times higher than the empty FPOHP. Additionally, the topological channel design greatly reduced the temperature difference between different heated regions, showing the self-regulation ability of temperature control on both uniform and non-uniform heating modes. The average thermal resistance of TO-FPOHP could be reduced by approximately 40 % as compared with that of CO-FPOHP. This study provides a feasible algorithm-based channel design strategy for FPOHPs, and new topological FPOHPs show attractive prospects for the cooling of multiple high-power electronic chips.