Working fluid flow visualization in gravity heat pipe

University of Zilina, Faculty of Mechanical Engineering, Department of Power Engineering, Univerzitná 8215/1, 01026 Žilina, Slovakia

^a Corresponding author: patrik.nemec@fstroj.uniza.sk

Published online: 28 March 2016

Abstract

Heat pipe is device working with phase changes of working fluid inside hermetically closed pipe at specific pressure. The phase changes of working fluid from fluid to vapour and vice versa help heat pipe to transport high heat flux. The article deal about gravity heat pipe construction and processes casing inside during heat pipe operation. Experiment working fluid flow visualization is performed with two glass heat pipes with different inner diameter (13 mm and 22 mm) and filled with water. The working fluid flow visualization explains the phenomena as a working fluid boiling, nucleation of bubbles, and vapour condensation on the wall, vapour and condensate flow interaction, flow down condensate film thickness on the wall occurred during the heat pipe operation.