| In the last few years,with the sustaining improvement of functionality and performance of electronic equipments,increasingly,the bulk of electronic devices are getting smaller,the number of modules assembled is going up so as the power,and the installation density and heat flux density of components are getting higher and higher.Therefore,more and more high requirements are put forward for the thermal control capability of electronic equipments.Microchannel heat sinks possess the advantages of compact structure,high heat transfer efficiency and good engineering realization.This is an effective heat transfer form and has become a research hotspot of domestic and foreign scholars.There are many forms of microchannel structures,whereas the heat dissipation effect of the serpentine microchannel heat sink and the microchannel heat sink with fins is the most ideal.In this research,the design of the MCHSs and optimization technology are learned extensively and deeply,and two innovative MCHS construction forms are put forward,namely,the innovative double-row serpentine microchannel heat sink and the tessellated finned microchannel heat sink.The heat sink structure with excellent flow and heat dissipation performance of the cooling system are obtained.Aiming at the issues such as the influence of the flow field design parameters on heat transfer performance and optimization of design parameters,the study of simulation and experiment were carried out,and the main results include:(1)Based on the analysis of the existing problems of the traditional serpentine channel,a new type of double-row serpentine microchannel heat sink structure(D-SMTH)is proposed,and the capability of the microchannel is simulated and evaluated.The simulation is carried out for double-row serpentine microchannel heat sink under different design parameters.To compared with the traditional single-row serpentine micro-channel heat sink(SMCF),the heat dissipation effect of the new type heat sink is obvious improved.The Nusselt number of the double-row serpentine microchannel heat sink with cross arrangement of imports/exports mode increases faster,and the average Nusselt number of the D-SMTH-A improves by 13.7% to the maximum extent,producing the ideal heat transfer effect.(2)A test platform for heat dissipation performance of double-row microchannel heat sink is designed and set up,correlative experiments are operated,and the simulation results are proved in the test laboratory.Through the analysis of the experimental data,it is concluded that the relative error between the experiment and the simulation is no more than 6%.The simulation results are in good accordance with the experimental outcomes of D-SMPF model.(3)In view of the existing problems of the traditional plate-finned DC microchannel heat sink,a new type of microchannel heat sink with tessellated fins(DMTF)is proposed,and the performance simulation modeling and analysis are carried out for the heat sink with different secondary channel structures.The simulation results show that under the same pump output power,the staggered imports/exports arrangement of the DMTF proposes in this paper takes obvious advantages over the traditional DMPF in terms of reducing thermal resistance and increasing Nusselt number.The paper finds that the thermal resistance and bottom temperature difference of the DMTF model are lower than that of the DMPF and the heat dissipation effect is more uniform.Compared with the existing model MRNH with annular fins,the Nusselt number increases by 13.6% at the same power.The baseplate temperature difference of the DMTF is reduced by 2 K compared with the MRNH,which does an important research significance for improving the uniform heat transfer performance of the microchannel heat sink.(4)A testing platform for heat dissipation performance of plate-finned microchannel heat exchangers with multiple imports/exports is designed and built,the correlative experiments are implemented,and the simulation outcomes are testified.Through the analysis and numeration of experimental result,it is concluded that the relative error between simulation and experimental measurement of plate-finned microchannel heat sink at different flow rates is not more than 6%,and the relative error between average Nusselt number is not more than 5%,which reveals that the simulative results are in good accordance with the experimental results of the DMPF.(5)By adapting genetic algorithm,and the flow field design parameters of the two microchannel constructions come up with in this research have been optimized.Basing on the objective functions of the temperature uniformity of cooling basement,the number and diameter of the through-holes in the double-row serpentine micro-channel heat sink,the width and angle of the chute in the tessellated finned microchannel heat sink are optimized respectively.The optimization results show that the optimal search error of the double-row serpentine microchannel heat sink is less than 2%,and that of the tessellated finned microchannel heat sink is less than 3%.Through the optimization,the Nusselt number of double-row serpentine microchannel heat sink is increased by 14.1% compared with the simulation results before optimization and the Nusselt number of the tessellated finned microchannel heat sink is improved by 12.7% before optimization.The effect of the heat transfer is prominently upgradation. |
PDF Full Text Request