小通道平行流扁管内纳米流体的流动换热特性研究  

An Experimental Study on Flow and Heat Transfer Characteristics of Nanofluids in Multiport Minichannel Flat Tube

作　　者：张冀[1] 刁彦华[1] 赵耀华[1] 张艳妮[1] 孙钦[1] 

机构地区：[1]北京工业大学建筑工程学院

出　　处：《工程热物理学报》2015年第5期1071-1076,共6页Journal of Engineering Thermophysics

基　　金：北京市自然科技基金重点项目(No.Z1004020201201)

摘　　要：本文对TiO₂-水,Cu水和SiO₂-水3种纳米流体在一种多孔小通道平行流扁管中的单相流动换热特性进行了实验研究。该扁管矩形通道水力直径1.67 mm,整个实验过程Re变化范围97⁶200。实验结果表明:纳米流体起到强化换热效果的同时,也伴随着阻力的增加。此外,纳米流体相对于基液,出现了转捩提前现象。Nu随体积浓度的增加,先增加后减小,使得每种纳米流体都存在一个最优浓度。0.01%的TiO₂-水纳米流体在Re=6200时,Nu增长最大,达到43%。最后,利用性能评价标准对纳米流体的适用性进行了综合评定,0.01%的TiO₂-水纳米流体具有最佳性能。This study experimentally investigated TiO_2-water,Cu-water and SiO_2-water nanofluid single-phase flow and heat transfer characteristics in a multiport minichannel fiat tube with a 1.65 mm hydraulic diameter.The experiments were performed with Reynolds number ranging from 97 to 6200.The experimental results indicate that friction factor and Nusselt number of the nanofluids were higher than those of water.Meanwhile,a slightly earlier laminar-turbulent transition was found for the nanofluids.Nusselt number increase with increasing volume concentration firstly and then decreases with the increase of concentration,leading to an optimal volume concentration.As Re =6200,Nusselt number increases by up to 43%for 0.01% TiO_2-water nanofiuid.Ti02-water nanofluids at 0.01% concentration exhibited the best performance on the basis of the evaluation criterion.

关 键 词：纳米流体 小通道平行流扁管 粒子尺寸 体积分数 

分 类 号：TK172[动力工程及工程热物理—热能工程]