A novel flow-modified heat pipe: Development and experimental investigation.

摘要

Heat pipes have been investigated, developed and applied in many industrial fields since 1964. However, heat pipe technology is still a relatively new topic in high heat flux environments such as are encountered in the metallurgical and energy industries. This study focused on the development of a novel heat pipe that can be used under high heat flux conditions. The state of the technology prior to this study was that heat pipes were not suitable for high heat flux applications.; Even though numerous patents have been granted for heat pipes and related applications, most are based on the basic concepts of the conventional heat pipe as detailed in the literature. Researchers have found that there are a number of problems with these heat pipes when they are applied in high heat flux environments. Thus, it was a prime objective of this study to develop a novel heat pipe that is suitable for such high heat flux operations. In addition, some basic fundamental issues regarding the overall makeup of heat pipes were also investigated and explained.; The fundamental study showed that the film boiling phenomenon can be a serious problem when a conventional heat pipe is used under high heat flux conditions. Film boiling can make a conventional heat pipe lose its ability for sustained heat transfer with a small temperature gradient.; The flow modified heat pipe that was invented and studied eliminates film boiling in the evaporator of the heat pipe. In this kind of heat pipe, a flow-modifier element was introduced into the heat pipe chamber to improve the heat transfer of the two-phase flow. The experimental data indicated that the flow modified heat pipe was dramatically better than a conventional heat pipe under a comparable high heat flux load. This novel heat pipe successfully combined the flow modified heat pipe and the loop heat pipe and, thus, effectively overcame film boiling by collapsing the formed films. It was shown that the novel heat pipes are suitable for high heat flux and high temperature operation where conventional heat pipes will only function at a fraction of the heat load.