Research On Heat Transfer Performance Of Mesh Vein Bionic Heat Sin

With the rapid development of electronic technology,electronic products are developing towards a highly integrated direction,and the multiplying power consumption will inevitably lead to the electronic chips in a small space to produce high heat flux and temperature,causing serious heat dissipation problems,resulting in the electronic chips can not work properly or even function failure.Therefore,the development of new heat dissipation technology is an urgent problem to be solved in the future development of electronic chips.As an active cooling technology,vapor chamber based on phase change heat transfer provides a solution,but it still cannot meet the development needs of electronic devices at present.Botanical studies have shown that transpiration of plant leaves is the main way of plant heat dissipation,which has the optimal structure after survival of the fittest for millions of years.The heat dissipation mode of vapor chamber is very similar to that of plant leaves,both of which use the principle of phase change heat dissipation.The application of plant leaf structure to the wick of vapor chamber has important research value for improving the heat transfer performance of vapor chamber.In this paper,based on the reticular vein structure of plants,combined with the idea of bionic vapor chamber,a new wick structure of vapor chamber was designed by using the randomly generated Tyson polygon to simulate the reticular vein structure,and the heat transfer performance of the new vapor chamber was studied through experiments.The main research contents are as follows:(1)Establish a reticular vein bionic wick model.The feature extraction of plant reticular vein structure was carried out to simplify the irregular polygon fine vein structure.The simplified physical model was obtained according to Tyson polygon,and the three-dimensional model of reticular vein structure was established.In this paper,two kinds of wick structures were designed:polygon as steam chamber(VC-B structure)and polygon vein as steam chamber(VC-G structure).At the same time,the shrinkage rate of different particle sizes of copper powder was tested,and the size parameters of the wick mold were optimized according to the shrinkage rate of copper powder to complete the construction of the wick mold model.(2)Prepare a reticular vein bionic wick structure of the vapor chamber.Based on the mesh vein biomimetic wick model,the edges of reticular vein polygon or polygon as supporting structure and steam cavity,sintered copper powder prepared the reticular biomimetic wick structure.The manufacturing process route of the vapor chamber in this study was designed,the bionic vapor chamber with different structural parameters was prepared,and the simplified thermal resistance model of the mesh vein bionic vapor chamber was established.The theoretical thermal resistance value of the vapor chamber was calculated to be about 0.20968℃/W.(3)Test and research on the heat transfer performance of bionic vapor chamber with reticular vein.A water-cooling test platform for heat transfer performance of vapor chamber was built,and the comparative experiments of heat transfer performance of vapor chamber under different copper particle sizes,different filling rate and different cooling water temperatures were analyzed.It is found that the heat dissipation efficiency of the vapor chamber with 250 mesh sintered copper particle size is the best one.Under the 10℃cooling water condition,the thermal resistance of the sample C2(the filling rate of 250 mesh sample is 58.19%)is 0.092℃/W,which is the lowest.And the maximum heat flux can withstand is 135W/cm~2.The vapor chamber sample prepared in this study has the best heat dissipation performance when the liquid filling rate is about 60-70%.By comparing the heat transfer performance of vapor chamber cooled at different temperatures,it is shown that lower cooling water temperature is beneficial to increase the maximum heat flux of vapor chamber,and the condenser of vapor chamber shows better temperature uniformity at higher cooling water temperature.Through the comparison experiments of vapor chamber with different structure,the influence rule of structure on heat transfer performance of vapor chamber is explored.It is demonstrated that vapor chamber with VC-G structure has lower thermal resistance and can withstand larger heat flux,while the temperature equalization performance of VC-B structure is better than that of VC-G structure.