In order to address the complexity of the process of two-phase flow boiling in pump-assisted separated heat pipe and the poor experimental reproducibility

an experimental apparatus of pump-assisted separated heat pipe was built to study the pressure gradient and heat transfer coefficient of boiling heat transfer for R134a serving as a medium of heat transfer

which were compared with those in open literature. It showed that the integration of pressure gradient by Muller-Steinhagen-Heck correlation fits experimental result well with an error bar below ±10%. Moreover

at vapor quality above 0.1

Mohseni correlation predicts the experimental heat transfer coefficient with an error bar of ±10%

while at vapor quality below 0.1

it does with some error bars above 30%. For the purpose of minimizing the large error bars a modified correlation was built. Efforts of above correlation results were conducted as a reference standard for experimental study

numerical simulation and optimization design of heat pipe system.