微肋阵通道沸腾起始点实验研究

以去离子水为工质，在质量流速G=292.8~412.2 kg/(m²·s)，入口温度T_in=50.6~81.5 °C，热流密度q"=10.1~87.1 W/cm²的条件下，对圆形、菱形和椭圆形微肋阵通道内沸腾起始点特性进行了实验研究。对微肋阵通道内单相对流传热和两相沸腾传热过程的分析结果表明，壁温和压降曲线的变化趋势均可作为沸腾起始点的判定依据。通过分析各实验参数对沸腾起始点热流密度的影响趋势，发现微肋阵通道内沸腾起始点热流密度随质量流速的增大而增大，但是随着入口温度的增大而减小；在相同工况条件下，圆形、菱形和椭圆形微肋阵通道沸腾起始点热流密度依次减小。

Experimental investigation of boiling incipience in micro pin fin heat sinks

An experiment study has been conducted to investigate the onset of nucleate boiling (ONB) characteristics of deionized water in circular, diamond and elliptic micro pin fin heat sinks. The experiments were carried out in a range of mass flux from 292.8 to 412.2 kg/(m²·s), inlet temperature from 50.6 to 81.5 °C, heat flux from 10.1 to 87.1 W/cm². The wall temperature and pressure drop distributions of the micro pin fin heat sinks were analyzed from single phase forced convection to two phase flow boiling heat transfer. The experiment results indicate that the ONB can be identified as the point at which deviations from single phase trend is shown as a sudden change in temperature and pressure drop versus the heat flux. A parametric study was explored to investigate the effects of the experimental parameters on ONB. The heat flux at the ONB increases with an increase in mass flux. However, raising the inlet temperature can cause a reduction on the heat flux at the ONB. Besides, the heat flux at the ONB in circular, diamond and elliptic micro pin fin heat sink decreases successively under the same experimental condition.