Study On Heat Transfer Enhancement Characteristics Of Array Jets In Micro-channel

With the rapid development of electronic chips,the problem of high heat flux heat dissipation during system operation has become the top priority.It is urgent to seek more efficient cooling technology.At present,among various cooling technologies applied in different fields,microchannel cooling and impingent jet cooling technologies are the research hotspots.In this paper,the micro-channel and array impingement jet cooling technology are combined to explore the heat transfer characteristics of jet micro-channel heat sink through numerical simulation and experimental research.The influence of the shape of column ribs,the height of column ribs,the arrangement of column ribs and the jet impact distance on the flow and heat transfer characteristics was studied by numerical simulation with ANSYS software.In the simulation calculation,the velocity inlet and the pressure outlet are adopted.The inlet velocity is 2.62-13.12m/s,and the outlet pressure is 0 Pa.Inlet cooling water temperature 283K,heating surface heat flux100W/cm~2.The results show that:compared with the rectangular column ribs,the heat transfer surface of the circular column ribs has lower temperature,higher convective heat transfer coefficient,and better flow and heat transfer performance.The heat transfer capacity of the column ribs in the bottom of the micro-channel is higher than that of the column ribs in the cross direction.The heat transfer and flow characteristics of different column height and jet impact distance are analyzed.The results show that with the increase of column height,the heat transfer coefficient will first decrease and then increase.At high Reynolds number,the convective heat transfer coefficient first increases and then decreases with the increase of jet impact distance.The larger the Reynolds number is,the more obvious this trend becomes.Based on the results of numerical calculation,the heat sink and heat dissipation platform of jet microchannel was built.The influences of the number of jet holes,depth of jet holes,arrangement of jet holes and diameter of jet holes on heat sink heat transfer efficiency of jet microchannels were investigated.Experimental working conditions:inlet volume flow 0.5L/min～2.5L/min,inlet cooling water temperature 283K,heat flux100W/cm~2.The results show that:with the increase of the number of jet holes,the heat transfer coefficient of the heat transfer surface will first increase and then decrease.The selection of the number of jet holes should take into account the interference between adjacent jets and the influence of jet impact velocity.The heat transfer coefficient decreases with the increase of jet hole depth.Under the same parameter conditions,the heat transfer effect of jet hole row is better than that of jet hole row.The heat transfer coefficient and pressure drop decrease with the increase of the diameter of the jet hole.By comparing the experimental results with the numerical results,it is found that the maximum relative errors of convective heat transfer coefficient and pressure drop are both within 15%,which proves that the simulation method is reasonable.The research results show that,compared with two single cooling technologies,micro-channel cooling and impingement jet cooling,the cooling technology combined with micro-channel and impingement jet integrates the advantages of heat transfer of the two,has higher heat transfer efficiency,and has broad research prospects.