TiO_2/R141b纳米流体应用于微槽道结构蒸发器的强化换热特性研究  

Effect of R141b-Based TiO_2 Nanofluids on The Thermal Performance of an Evaporator With Rectangular Micro-Channels

作　　者：刁彦华[1] 王瑞[1] 刘岩[1] 赵耀华[1] 郭磊[1] 汪顺[1] 

机构地区：[1]北京工业大学建筑工程学院,北京100124

出　　处：《工程热物理学报》2013年第6期1137-1141,共5页Journal of Engineering Thermophysics

基　　金：北京市自然科学基金重点项目(No.Z1004020201201)

摘　　要：本研究以微槽道结构蒸发器为研究对象,以TiO_2/R141b纳米流体为工作介质,在不同运行压力条件、不同纳米流体体积分数下对蒸发器的传热特性进行了实验研究。运行压力为0.86×10~5 Pa、1.0×10~5 Pa,纳米颗粒的体积分数范围为0.001%～0.1%。运行压力为0.86×10~5 Pa时,体积分数为0.001%、0.01%纳米流体会具有明显的强化换热的效果;体积分数为0.1%的纳米流体在高热流密度时出现传热恶化的状况。在运行压力为1.0×10~5 Pa时,体积分数为0.001%、0.01%的强化效果不明显,而体积分数为0.1%的纳米流体随着压力的增加,传热恶化程度加剧。本研究还对纯工质在微槽道结构表面纳米颗粒沉积层的蒸发/沸腾传热特性进行了实验研究,实验结果表明：纳米粒子沉积层的存在对纳米流体在微槽道结构内蒸发/传热特性具有重要的影响。In this paper,it was investigated experimentally that the effect of TiO_2/R141b nanofluids as working fluid on the thermal performance of micro-channel surface at different pressures and particle concentrations of nanofluids.The operational pressures in this study were 0.86×10~5 Pa and 1.0×10~5 Pa,and the volume concentration of nanoparticle was in the range of 0.001%、0.01%、0.1%, respectively.In operating pressure of 0.86×10~5 Pa,nanofluids with concentrations of 0.001%and 0.01%,the corresponding heat transfer coefficients are larger than that of the base fluid.For the concentration of 0.1%,when the heat flux is higher,compared with the pure fluid,the heat transfer coefficient is lower.At pressure of 1.0×10~5 Pa,,for the concentration of 0.1%,the results indicate the heat transfer deteriorated in the range of higher heat flux.Under the same operating pressure,the results also show that for the concentrations of 0.001%and 0.01%,the heat transfer enhancement effect is not obvious.Heat transfer characteristic for TiO_2 nanoparticle-coated surface with rectangular microchannels were experimentally studied.The experimental results demonstrated that nanoparticle deposed covering has an important influence on the heat transfer behavior.

关 键 词：蒸发 沸腾换热 纳米流体 微槽道 强化换热 纳米沉积层 

分 类 号：TU83[建筑科学—供热、供燃气、通风及空调工程]