Design, Manufacture And Heat Transfer Performance Of Three-dimensional Wedge-shaped One-way Heat Pip

With the rapid development of electronic information industry,electronic products with microelectronic technology as the core gradually tend to miniaturization,high performance and high density packaging,resulting in a substantial increase in the heat flux of electronic products.Heat pipe,as a phase change heat transfer device,is widely used in thermal management of electronic products for its high heat transfer property and high reliability.Because the traditional heat pipe has two-way heat transfer,when the temperature of the outside is higher than that of the internal electronic device,the heat from the outside will be transferred to the electronic device through the heat pipe,causing thermal damage to the electronic device.In order to prevent external heat transfer,unidirectional heat pipes with asymmetric axial heat transfer characteristics are proposed.However,the current one-way heat pipe has some problems such as limited heat transfer direction or too short heat transfer distance.Aiming at the above problems,this paper designs a unidirectional heat pipe with threedimensional wedge-shaped flow channel as the core to realize long-distance axial asymmetric heat transfer in the horizontal direction.The main research contents and conclusions are as follows:(1)Inspired by goose feather fiber structure and asymmetric ratchet structure,a threedimensional wedge channel was proposed to realize liquid directional flow,and theoretical analysis was carried out to determine the main structural parameters affecting liquid directional flow.In addition,the structure of unidirectional heat pipe was designed,and the threedimensional wedge-shaped flow channel was used as the liquid return channel in the heat pipe,and the equivalent thermal resistance network diagram of forward and reverse heat transfer was established for thermal resistance comparison.(2)Simulation software was used to numerically simulate the liquid flow condition of 3D wedge channel under different incline Angle,channel depth,wedge Angle and unit length.The influence of various structural parameters on liquid directional flow was analyzed,and the structural parameters with the best liquid directional flow effect were obtained.(3)According to the numerical simulation results of three-dimensional wedged flow channel and the actual manufacturing conditions,the size of three-dimensional wedged flow channel was determined,and the flow channel was fabricated on red copper.The results show that the directional flow effect of absolute ethanol is better than that of deionized water in the three-dimensional wedge-shaped flow channel without hydrophilic and hydrophobic treatment.In addition,according to the unidirectional heat pipe design scheme,the corresponding parts of the heat pipe are manufactured and packaged.(4)The experimental test platform for unidirectional heat pipe was designed and built,and the heat transfer performance of unidirectional heat pipe was tested.The effects of different liquid filling rates,heating power and working medium types on the heat transfer performance of unidirectional heat pipe were studied.The results show that the axial temperature uniformity is the best when the liquid filling rate of the heat pipe is 35%.When the liquid filling rate is 25%and the heating power is 5W,the unidirectional heat pipe has the best axial asymmetric heat transfer,and the thermal rectification coefficient is 5.07.In addition,the unidirectional heat pipe with absolute ethanol as working medium has better heat transfer performance than the unidirectional heat pipe with deionized water as working medium.