Research On A Novel Kind Of Flat Micro Heat Pipe With Glass Fiber Wick Structure

A novel flat micro heat pipe with glass fiber wick structure has been presented in this paper, and the numerical simulation and experimental investigation has been done to this new kind of heat pipe. The flat heat pipes have very high heat conductivity, need no extra drive force. And it is an important candidate for the electronics cooling problem of high heat flux in micro or mini space. For the advantages of micro heat pipes, they are widely used in a lot of areas such as IC chips, aviation, spaceflight, biology and medicine.The grooved heat pipe have some disadvantages as the following: humdrum shape of cross-sectional area limits the capillary force; the number of micro grooves is limited by the width of the micro heat pipe; interface shear stress between the liquid and vapor generated by micro-grooved wicks debases the characteristic of micro heat pipe. To solve these problems, a novel flat micro heat pipe with glass fiber wick structure is proposed in this paper. The glass fiber can be put multilaterally inside the heat pipe so as to form much more channels; the cross-sectional area of the channel is formed by three tangent circles and the tangent circles form very sharp angle in the channel cross-sectional area, which could produce capillary force efficiently; the channels of vapor and liquid are separated, so the vapor and liquid interface shear stress is completely avoided.Firstly the structure of the novel heat pipe is designed. Glass fiber is chosen as the wick structure, copper as the hell material, and ethanol as working fluid. Then numerical simulation is undertaken to analyze the thermal performance of the micro flat heat pipe. A one-dimensional steady-state model is established by predigesting, which is for analyzing the velocity of liquid and vapor, meniscus radius of the evaporator end and the maximum heat transport. The optimization dimension has been obtained by simulating the model and analyzing the real situation. The experiment has been conducted to validate the veracity of the model. The maximum heat transport obtained by experiment is compared with the results predicted by the model and show good agreement. The results are also compared with the results of the grooved heat pipe and copper plate, and it is found that the novel heat pipe has better performance and greater heat transport.