三角形与梯形凹槽微通道流动换热特性试验研究

Experimental study on water flow and heat transfer characteristics in microchannel with triangular grooves and microchannel with trapezoidal grooves

为研究壁面凹槽对微通道热沉流动和传热性能的影响,设计了两种侧壁具有不同凹槽结构的微通道热沉模型,以去离子水作为流体介质展开试验,并通过综合进出口压降、摩擦因子、加热面温度、努塞尔数和综合传热因子评价侧壁凹槽结构对流动换热特性的影响。结果表明,当凹槽开口长度同为1 mm、开口倾角同为25°时,三角形凹槽微通道的压降相对于梯形凹槽最高提高了9.36%;当加热功率同为240 W、入口温度同为20℃时,三角形凹槽微通道散热能力始终大于梯形凹槽微通道;当通道内雷诺数处于试验设定的500~3500区间时,三角形凹槽微通道的流动与传热综合性能始终优于梯形凹槽微通道;设计微通道热沉侧壁凹槽结构应优先考虑三角形凹槽结构。

In order to study the effect of wall grooves on the flow and heat transfer performance of microchannel heat sink,two microchannel heat sink models with different groove structures on the side walls were designed and experiments were conducted using deionized water as the fluid medium.The effect of the sidewall groove structure on the flow heat transfer characteristics was evaluated by combining the inlet and outlet pressure drop,friction factor,heating surface temperature,Nusselt number and integrated heat transfer factor.The experimental results show that the pressure drop of the triangular groove microchannel was increased by 9.36%compared to the trapezoidal groove with the same groove opening length of 1 mm and the same opening inclination angle of 25°.At the same heating power of 240 W and the same inlet temperature of 20℃,the heat dissipation capacity of the microchannel with triangular grooves is always greater than that of the microchannel with trapezoidal grooves.When the Reynolds number in the channel is experimentally set in the range of 500 to 3500,the combined flow and heat transfer performance of the microchannel with triangular grooves is always better than that of the microchannel with trapezoidal grooves.The design of the groove structure on the sidewall of the microchannel heat sink should give priority to the trapezoidal grooves.