V-groove Rectangular Microchannel Flow And Heat Transfer Characteristics Of Study

With the rapid development of Microelectronic Systems,electronic components tend to be more integrated and high power,the problem of heat dissipation under high heat flow becomes difficult.Microchannel heat exchangers have the characteristics of compact structure and high heat exchange efficiency.It is a reliable technology to solve the problem of heat dissipation of electronic components.This article is based on the finite volume method,under constant heat flux and liquid laminar flow,the structure optimization and orthogonal experiment optimization of the bottom groove of rectangular single microchannel are carried out by numerical simulation,and the overall flow and heat transfer characteristics of the optimal groove rectangular microchannel heat exchanger are comprehensively analyzed.The research process and conclusions are as follows:(1)Four different groove structures were set at the bottom of the single rectangular microchannel: V-groove,V-groove inverted round,rectangular groove and rectangular groove inverted round,and flow and heat transfer characteristics are compared and analyzed by numerical simulation.The results show that in the range of hydraulic diameter of 0.375 mm and Reynolds number of 110-230,the arrangement of grooves reduced the maximum surface temperature of microchannel,effectively increaseed the heat exchange area and enhanced the disturbance effect of fluid,thereby enhanced the heat transfer of the microchannel.Among the four groove structures,the highest surface temperature of V-shaped rectangular microchannel is the lowest,the values of heat transfer factor and enhanced heat transfer factor PEC are the greatest.Compared with the conventional microchannel,its heat transfer factor increases by 26.85-42.76%,and friction factor decreases by 12.96-22.45%.(2)Taking the highest surface temperature as the experimental index,a 6-factor and 5-level orthogonal test was designed to optimize the single rectangular microchannel with V-shaped groove structure.The results show that the optimal combination of Vgroove rectangular single microchannel is the depth of the micro groove is 0.2mm,the width of the micro groove is 1.2mm,the thickness of the substrate is 1mm,the angle of the micro groove is 30°,the number of the micro groove is 18,and the height of the microchannel is 0.8mm.In the range of the entrance velocity of 0.3 ~ 0.6m/s,compared with the former V-groove rectangular single microchannel model,the maximum surface temperature of the optimized microchannel is reduced by 28.0641?.The friction factor of optimized microchannel model is the smallest and heat transfer factor is the largest.It has an enhanced heat transfer factor of 0.56~1.08 times,which with the best comprehensive performance.(3)Established a three-dimensional model of V-groove rectangular microchannel heat exchanger with 6,12,and 18 channels,numerically analyzed the flow and heat transfer characteristics of the corresponding named MCHD6,MCHD12 and MCHD18 heat exchangers,and using PEC to comprehensively analyze their thermal stability.The results show that the number of channels has an important influence on the performance of microchannel heat exchanger.In the range of Reynolds number 224~746,the friction factor of MCHD6 is 3.5~3.7 times of MCHD18,and 2.268~2.4 times of MCHD12.The heat transfer enhancement of the bottom groove of MCHD12 is more obvious than that of MCHD6 and MCHD18,and the maximum surface temperature of MCHD12 is smaller,the difference of heat transfer temperature is the largest,the value of enhanced heat transfer factor PEC is relatively stable,so the flow channel distribution is more uniform.