Structural Design And Performance Research Of One-way Heat Pipe Based On Reverse Choke Air Channel

With the rapid development of electronic information technology and the trend of miniaturization,integration and high performance of electronic devices,the power density of electronic components is increasing day by day,and the problems of heat dissipation and heat transfer need to be timely solved.Heat pipe is an efficient cooling element with latent heat exchange phase change cooling,and its high heat transfer efficiency and good stability make it an excellent choice to solve heat dissipation problems in many fields.The unidirectional heat pipe is one of the heat pipes with controllable heat transfer direction..Most of the existing unidirectional heat pipes can only work with the help of external field(mainly gravitational field,electromagnetic field,etc.),and their application has certain limitations.In this paper,a new type of unidirectional heat pipe is proposed to realize unidirectional heat transfer by controlling the flow direction of gas phase working medium.The new unidirectional heat pipe has been systematically and deeply studied from the aspects of structure design,numerical simulation,manufacturing process and performance testing.The main research work is as follows:(1)Determine the overall design scheme of the unidirectional heat pipe,and analyze the flow characteristics of the working medium of the unidirectional heat pipe based on the fluid phase change heat and mass transfer theory and the basic theory of the heat pipe,The thermal resistance network of the unidirectional heat pipe heat transfer is established and the thermal resistance of forward and reverse heat transfer is compared.It is theoretically verified that the unidirectional heat pipe designed in this paper has unidirectional heat transfer performance.(2)The finite element simulation software Fluent is used to numerically simulate the steam channel structure of the unidirectional heat pipe.By simulating the positive and reverse flow when the Angle,depth,series and number of the channel structure change,and combining with the overall structural size requirements of the unidirectional heat pipe,the optimal structural parameters of the unidirectional heat pipe steam channel are obtained.(3)The structure of suction core,working medium and material of each part of the unidirectional heat pipe are determined.Each part of the heat pipe was manufactured by mechanical machining method and the heat pipe was encapsulated,then the subsequent processing techniques such as cleaning,sealing leak detection,vacuum pumping and liquid injection are performed on the heat pipe,and the manufacture of the unidirectional heat pipe is completed.(4)The heat transfer performance test device of the unidirectional heat pipe is built,and its heat transfer performance are studied.The axial temperature distribution of the outer wall of the heat pipe is analyzed under different heating powers.When the heating power was lower,the axial temperature uniformity of the heat pipe is better.With the increase of heating power,the axial temperature difference of heat pipe increases gradually,and the temperature homogeneity becomes worse.Comparing the forward and reverse heat transfer performance of the unidirectional heat pipe,it is verified that the channel structure has the function of controlling steam one-way flow.The effects of heating power and liquid filling rate on heat transfer performance and unidirectional performance of the unidirectional heat pipe were analyzed.