Thermal conduction mechanism of multi-walled carbon nanotubes-deionized water nanofluids and experimental research in gravity heat pipe

An improved model of thermal conduction of multi-walled carbon nanotubes – deionized water (MWCNTs-DW) nanofluids is proposed based on the Xue model by considering interfacial nanolayer, analyzing heat conduction, derivating thermal conductivity of MWCNTs-DW nanofluids and applying MWCNTs-DW nanofluids to the research of heat transfer in gravity heat pipe. Different mass fraction of nanofluids gravity heat pipe are prepared and investigated using the nanofluid as the work liquid and the carbon steel pipe as material. The result shows that the interface nanolayer increases the effective thermal conductivity and the mass fraction of 2% is best performance under the same conditions, the heat transfer coefficient of nanofluids gravity heat pipe increases by 40% to the max than that of the base fluid water.