Study On Flow And Heat Transfer Characteristics And Influencing Factors Of Cooling Channels In Microsystems

With the development of science and technology and the actual needs of modern industry,mechanical and electronic devices are gradually developing in a highly integrated and miniaturized direction,resulting in a sharp increase in heat flux density during the use of micromachines and electronic devices,making machinery and electronics The temperature of the component is too high,which can easily cause damage to the device.Microchannel heat exchangers have been widely used in MEMS and microelectronic systems because of their small size,large heat exchange area per unit volume and effective heat transfer enhancement.Domestic and foreign studies have shown that the structural size of the microchannel heat exchanger is a crucial factor affecting the heat transfer performance of the heat exchanger.Therefore,the structural design and optimization of the microchannel heat exchanger is to improve the microchannel heat exchanger.The heat transfer performance and the improvement of microchannel flow characteristics have important practical and theoretical value.In this paper,the flat heat transfer microchannel is used as the basic model,and the heat transfer characteristics of the heat transfer microchannel are studied by numerical simulation.On the basis of the basic model verification,the inlet shape of the microchannel was changed,and the main influencing factors of the inlet shape on the heat transfer performance were discussed through the comparative analysis of five different inlets: the flow path length was analyzed on the analysis of the inlet shape.The simulation analysis of the influence of heat transfer performance,and proposed the structure of the broken line runner to replace the DC channel.The results show that the influence of the inlet shape on the heat transfer performance mainly depends on the hydraulic perimeter and the gravity center height of the inlet shape.Under the same inlet flow rate,the longer the inlet hydraulic circumference,the lower the center height of gravity,the better the heat transfer performance of the microchannel and the more uniform the temperature distribution.The fold line flow channel can effectively optimize the temperature distribution during the microchannel heat exchange process and strengthen the mixing of the heat transfer medium in the micro channel.In order to improve the performance of the heat exchanger,this paper proposes a double-layer staggered microchannel arrangement method.The single-layer optimized microchannel model and the double-layer staggered optimized microchannel model are compared and analyzed under different inlet speeds.It is found that the micro-channel arrangement of the double-layer staggered column can strengthen the mixing of the working medium in the micro-channel and reduce the temperature difference of the working medium in the flow section.The average temperature of the chip is 4 °C lower than that of the single layer arrangement by double-layer staggered arrangement.