Enhanced capillary performance of grooved nanocarbon foams as wicks for heat pipes

An effective heat pipe needs a great amount of working liquid to be moved quickly from the cold end to the hot end. That is why capillary performance works as a critical factor to evaluate the potential of a wick for highefficient heat pipes. However, good capillary performance only means that the liquid can be transferred quickly; the amount of liquid transferred during capillary rising also needs to be taken into account. In this work, novel grooved nanocarbon foam (GNCF) wicks were fabricated with good capillary performance and a large capillary rise amount. Grooves with different numbers, depths, and widths were formed on the nanocarbon foams (NCFs) and the effect of these factors on the capillary performance was studied. The results indicate that the groove is beneficial to improve the capillary performance of NCFs due to the enhanced permeability and feeding effect. The capillary performance is achieved with a capillary rise height of 45 mm in 14 s. It is 2.5 times as high as that of the NCF and better than some other published results. Moreover, because the GNCFs have a superhigh porosity of 0.99, they are capable to transfer much more working liquid per time than other wicks with similar capillary performance.

Automated summary

Novel grooved nanocarbon foam (GNCF) wicks with good capillary performance and a large capillary rise amount were fabricated and studied in this work. The results show that grooves enhance the capillary performance of nanocarbon foams (NCFs) and the superhigh porosity of GNCFs allows for more efficient liquid transfer.