周期性扩缩微通道接触冷凝流动及传热特性  

Contact condensation flow and heat transfer characteristics in periodic expansion-constriction microchannels

作　　者：刘冬稔 刘肖 LIU Dong-ren;LIU Xiao(School of Mechanical Engineering,Yangzhou University,Yangzhou 225127,Jiangsu Province,China)

机构地区：[1]扬州大学机械工程学院,江苏扬州225127

出　　处：《化学工程》2021年第3期17-21,共5页Chemical Engineering(China)

基　　金：江苏省自然科学基金资助项目(BK20180936)。

摘　　要：为了研究各参数对微通道流动及传热特性的影响,以水和水蒸气为工质,对周期性扩缩微通道接触冷凝流动及传热特性进行了实验研究。实验结果表明:周期性扩缩微通道内的主要流动形式为弹状流,在蒸气量不变的情况下,改变液相流量对流型的影响不大。由于周期性扩缩微通道能够有效打破流体的边界层,与直通道相比周期性扩缩微通道对传热有较大的强化作用,并且周期性扩缩微通道内流体的传热过程受流量的影响较大。此外,周期性扩缩微通道传热效果的提升以压力降的升高为代价,在实际应用中应平衡两者之间的关系,获得最佳效果。In order to study the effects of different parameters on the flow and heat transfer characteristics of microchannels,the contact condensation flow and heat transfer characteristics in periodic expansion-constriction microchannels were studied experimentally,using water and steam as working medium.The results show that slug flow is the main flow pattern in periodic expansion-constriction microchannels.With constant steam volume,the change of liquid flow rate has little effect on flow pattern.Compared with the straight channel,the periodic expansion-constriction microchannels can effectively break the boundary layer of the fluid and enhance the heat transfer.The heat transfer process of the fluid in periodic expansion-constriction microchannel is greatly affected by the flow rate.In addition,the increase of heat transfer effect of periodic expansion-constriction microchannels lead to the increase of pressure drop.In practice,the relationship between pressure drop and heat transfer should be balanced to achieve the best results.

关 键 词：膨胀-收缩 传热 微通道 两相流 

分 类 号：O359.1[理学—流体力学]