中文摘要：

为了探究微通道内流动沸腾及传热现象的机理,以制冷剂R22为工质在矩形微通道内进行了流动沸腾及可视化实验。结果表明,在核态沸腾下传热系数受质量流率的影响较小,却随着热流密度的增加而快速增加;微通道的尺寸越小,传热效果越好,水力直径为0.92 mm和1.33 mm微通道内的传热系数比2 mm微通道内的传热系数分别提高约25%、12%;根据实验值与预测值的对比情况,在Oh H K等[15]和Yun R等[7]模型基础上拟合得到新的传热系数预测关联式,平均绝对误差降至8.8%;通过可视化实验发现,在临界热流密度下微通道内出现波浪式气体层的现象。

英文摘要：

To investigate the characteristics of flow boiling and heat transfer in microchannels,experiments was carried in rectangular microchannels using refrigerant R22 as working fluid,and visualization experiment was performed using high speed camera. The results show that： heat transfer coefficient is barely influenced by the mass flow rate,but it increases rapidly along with the increment of the heat flux.The smaller the size of microchannels,the better heat transfer effects. Under the same condition of heat flux and mass flow rate,the values of heat transfer coefficient in 0. 92 mm and 1. 33 mm microchannels increase by 25% and 12% respectively compared to that of 2mm. A new correlation based on the models of Oh H K et al[15]and Yun R et al[7]is shown to provide very good predictions,evidenced by an overall MAE of 8. 8%. Wavy vapor layer was observed under the critical heat flux in visualization experiment.