泡沫铜式和微槽式均温板散热性能的对比研究

Research on heat dispassion performance of vapor chambers

建立了较为完善的均温板性能测试实验台和可视化试验系统,研究发现:泡沫铜均温板的传热性能优于微槽式均温板,不同热流密度下的轴向热阻与市售均温板相当;在未失效前,均温板热阻达到0.2 K/W;影响均温板性能的主要参数是毛细压差力、渗透率和充注率,毛细压差力的提高对均温板的性能提升有着显著的效果.在可视化试验中,对于泡沫铜均温板,当充液率和热流密度较低时,蒸发面的传热主要是薄液膜蒸发机制;而当充液率和热流密度较高时,均温板内蒸发面的传热为池沸腾机制.对于微槽式均温板,当热流密度较高时,能明显观察到微槽内产生的气泡,即均温板蒸发面的传热属池沸腾机制.

Different forms of vapor chamber（ grooved and copper-foam vapor chambers） are designed and produced,the processing technology of the vapor chambers is studied,and the performance tests are also carried out. It is found that the overall performance of the copper-foam wicks is better than that of grooved wicks. Their axial thermal resistances are similar to those of the vapor chambers bought. The thermal resistances of the vapor chambers can reach up to 0. 2 K/W. From the tests,the start-up time of the grooved vapor chamber is faster than that of the copper-foam vapor chamber. A visualization experiment is also explored. For the copper-foam vapor chamber,if the filling ratio and heat flux are lower,the heat transfer mechanism of evaporation surface arises from thin film evaporation process,while the filling ratio and heat flux are higher,the heat transfer mechanism arises from the pool boiling process. For the micro-channel vapor chamber with filling ratio 100%,if the heat flux is high,the bubble emerged can be observed distinctly in the micro-channel. It means that the boiling process of the evaporation surface is dominated by the pool boiling mechanism.