Design And Research Of Heat Dissipation Assembly With Microgrooves Heat Pipes For Multiple Heat Sources Cooling

With the development of electronic devices toward high performance,integration,and miniaturization,the heat dissipation problem of discretely distributed electronic components with high heat flux in a limited space needs to be solved urgently.As an efficient passive thermal control element utilizing phase change heat transfer,the heat pipe has a good application prospect in heat dissipation systems.Aiming at the problem of heat dissipation of discretely distributed electronic devices in the aerospace and other fields,this research proposed a design idea of heat dissipation assembly,and analyzed its heat dissipation effect and influencing factors combined with the actual conditions.In addition,preliminary experimental research was carried out on the main influencing factors such as the relative position of the heat sources and the input power,so as to provide a reference for the rational arrangement of heating elements and the optimal design of heat dissipation assembly in engineering applications.Based on the design requirements of light weight,low thermal resistance and high reliability,this research proposed a design of heat dissipation assembly with microgrooves heat pipes and heat dissipation substrates,which can be adapted to the flat limited heat dissipation space and the working conditions where the heat source and the cold source are located in different planes.The numerical simulation results under actual application conditions show that the layout and heat transfer performance of the heat pipe have an important impact on the thermal control effect,and a better arrangement of the evaporation section covering more heat source area can reduce the maximum temperature of the heat source by about 2.0?.After the optimization of the substrate structure,the maximum temperature of the heat source area can be controlled within 70?under the requirements of light weight,and the temperature rise of the high heat flux heat source near the optimized area is relatively obvious.Based on the theory and analysis of flow and heat transfer of the heat pipe,a preliminary theoretical calculation of the designed flat aluminum-acetone microgrooves heat pipe was performed.The heat transfer limit is about 42.7W and the thermal resistance is about 0.30K/W of the heat pipe at a working temperature of 65?,which meets the heat transfer performance requirements of heat dissipation assembly.After testing,the heat pipe can meet high temperature storage requirements and leakage rate requirements,and can be applied to aerospace and other fields that have strict requirements on the reliability of thermal control components.The thermocouple temperature measurement method was used to carry out an experimental study on the working conditions of different input power under four heat sources area arrangements.Taking the working conditions of P₁=10W,P₂=20W as an example,when the distance between the two heat sources is increased from 40mm to 120mm,the total thermal resistance is reduced by 56.4%,and compared with P₁=20W,P₂=10W,the total thermal resistance can be reduced by up to 39.0%.Therefore,arranging the heat source with higher power closer to the condensation section or appropriately increasing the center distance of the heat source can significantly reduce the maximum temperature of the measuring point on the surface of the heat pipe and increase the temperature uniformity.At the same time,the gravitational bending of the condensing section and the appropriate working temperature can also improve the heat transfer performance of the heat pipe to a certain extent.In the layout of electronic devices and the design of heat dissipation assembly,it is necessary to comprehensively consider the relative position of the heat pipe and the heating element and the influence of the overall structure on the thermal control effect.