Design And Experimental Study Of High Performance Miniature Channel Heat Sinks

With the rapid development of the packing density of the electronic device,the heat dissipation of the electronic device becomes more and more obvious. Microchannel heat sinks have been a hot spot for domestically and abroad scholar now because of the advantages of high surface-to-volume ratio in limited space, strong cooling abilities and compact structures. The design requirements in this thesis were that the cooling system could remove a heat flux of 20 W/cm2 on a 40mm×20mm heat transfer surface, while the allowable wall temperature was 60℃.A high performance of a miniature channel with staggered fin was proposed to realize the aim. Numerical studies were conducted to compare the performances of staggered fin and conventional parallel heat sinks, the results showed that staggered fin structure can obtain better cooling performance, which increased the heat transfer coefficient up to 18%, and resulted a problem of larger pressure loss. The heat transfer enhancement and power consumption increase mechanism of the staggered fin was also analyzed from the field synergy point. The staggered fins were round off , a comparison of modified staggered fin miniature channel and normal staggered fin miniature channel were performed, it was showed that the modification had little impact on the performance. Therefore, the optimization of popular staggered fin miniature channel heat sink was made in this thesis. Through the study, It was found that there was an optimum fin length ratio, an optimum fin width and an optimum fin height for the staggered fin miniature channel heat sink. The numerical results indicated that inlet and outlet pipes had lager impact on the pressure lose of staggered fin miniature channel heat sinks, which accounted for more than 50%. It was found that the real pressure drop of heat sink could less than the whole pressure.According to the optimized results and processing technologies, four staggered fin miniature channel heat sinks were fabricated. Experimental investigation was conducted to determine the heat transfer and flow characteristics of the heat sinks. The cooling performance was investigated and analyzed under various operation situations, which concluded different input heating power, flow rate, structure parameters. The following conclusions were obtained: The average wall temperature of heat sink was linear to heat flux and the dynamic response time for heating power was only one minute; A larger flow rate resulted in a better heat transfer performance, but a greater pressure drop; When the parameter of the staggered fin miniature channel heat sink was Y=1, Wc=2.1mm , the performance was best. In addition, the cooling system could effectively remove a heat flux of 30W/cm2 under 4.17 ml/s flow rate, while the wall temperature was below 60℃, which fully meet the topic requests. Numerical results were also obtained based on the experimental conditions. A good match was found between the numerical and experimental temperatures. Compared with honeycomb structure, the cooling performance of staggered fin miniature channel heat sink was more than twice. The results and conclusions from this thesis could provided the important insights to the design of staggered fin miniature channel heat sink.