分别在有纳米颗粒沉积和没有纳米沉积的情况下,对不同纳米颗粒浓度的Al2O3/H2O纳米流体在竖直圆管内的流动和换热特性进行实验研究,分析了纳米颗粒在竖直圆管换热面上的沉积对管内纳米流体流动及换热特性的影响.结果表明:纳米颗粒的沉积对流动特性有显著影响,对换热特性的影响并不明显;随着纳米颗粒浓度的增大,摩擦阻力系数和换热能力都有显著增加.“,”The effects of nanoparticles deposition on the nanofluid flow and convective heat transfer characteristics in the vertical tube were studied experimentally.Flow and heat transfer characteristics of Al2O3/H2O nanofluid in the vertical tube were studied under different nanoparticle concentration in the case of nanoparticles deposition and no nanoparticle deposition respectively.The results showed that nanoparticles deposition have significant effects on the flow characteristics but the effect on heat transfer characteristics is not obvious,and with the increasing of the nanoparticle concentration,the frictional coefficient and the heat transfer capacity have been significantly enhanced.