Study On Performance Of Flat Heat Pipe Radiator For High Power IGBT

IGBT is a kind of semiconductor composite electronic component with high frequency,high voltage and high current.It will have a large power loss during operation,which will generate a large amount of heat and increase the temperature of its modul.The flat heat pipe fully utilizes the rapid heat transfer properties of phase change heat transfer and vapor diffusion,which has the advantages of extremely high heat conductivity,reversibility of flow direction,environmental adaptability,and also has a soaking action for eliminating local overheating of the heat source.Therefore,the flat heat pipe radiator has a good application prospect.In this paper,the performance of the flat heat pipe radiator is studied through theoretical and experimental methods,the following work is carried out:Firstly,the steady-state thermal resistance model of flat heat pipe radiator is established.The influence of different factors on heat transfer characteristics is calculated and analyzed.It is found that when the heat source size is small or the bottom surface of the radiator is large,and the contact thermal resistance between the heat source and the heat sink is small,its heat transfer advantage is more obvious compared with the aluminum substrate heat sink.It is more suitable to increase the thickness of the vapor chamber than to increase the thickness of the shell,when it is necessary to increase the thickness of the bottom plate.Secondly,the three-dimensional calculation model of thermal and hydrodynamic of flat heat pipe is established using COMSOL Multiphysics software.The distribution characteristics of temperature field,flow field and pressure field and related influencing factors are analyzed.The pressure drop direction in the steam chamber is from the heat source to the periphery,and the maximum velocity is slightly above the heat source.The temperature of the heat source is reduced by distributing the heat source,and the maximum pressure and pressure drop in the steam chamber and the maximum velocity of the vapor are decreased.As the heating power increases,the vopor working pressure,pressure drop and maximum flow rate increase.As the condensing surface heat transfer coefficient increases,the vapor working fluid pressure drops,but its pressure drop and maximum flow rate increase.Next,the air-cooling heat-dissipation experimental platform was built to investigate the difference in heat transfer performance between the flat heat pipe radiator and the aluminum substrate heatsink under the two different heat flux densities.The results show that the flat heat pipe radiator has stronger thermal response and stable axis.Both the radial and radial temperature differences are smaller.Moreover,the numerical calculation model of the radiator is established,and the temperature field of the flat heat pipe at different heat flux and wind speed is calculated,and compared with the experimental results,the accuracy of the model is proved.Finally,according to the theoretical calculation results,the optimization calculation analysis is completed taking into account the principle of heat transfer efficiency and economy,from the fields of structural parameters of the flat heat pipe,the fin structure parameters,the overall configuration and the contact thermal resistance,which is helpful to guide the actual project.