纳米制冷剂在微通道中对流换热特性及熵产分析  

Analysis on Convective Heat Transfer Characteristics and Entropy Generation of Nanorefrigerant Flow in Microchannel

作　　者：郭文华 彭浩 GUO Wenhua;PENG Hao(Merchant Marine College,Shanghai Maritime University,Shanghai 201306,China)

机构地区：[1]上海海事大学商船学院,上海201306

出　　处：《制冷技术》2018年第4期6-10,共5页Chinese Journal of Refrigeration Technology

基　　金：上海高校青年东方学者人才计划项目(No.QD2016045)

摘　　要：本文对R134a纳米制冷剂在微通道中的对流换热特性和熵产情况进行了数值研究,其中纳米颗粒包括氧化铜(CuO)和碳纳米管(CNT)、体积分数范围为0～4%、雷诺数(Re)范围为400～2,000。结果表明,对流换热系数和摩擦压降随着体积分数和雷诺数的增加而增大;Re=1,200时,体积分数为4%的R134a-CuO和R134a-CNT纳米制冷剂的对流换热系数比纯R134a分别高出了45.7%、125.7%,摩擦压降分别高出了192.4%、161.8%。热熵产随体积分数和雷诺数的增加而减小,摩擦熵产随体积分数和雷诺数的增加而增大;R134a-CuO和R134a-CNT纳米制冷剂的总熵产最小产生条件分别为体积分数2%、Re=1,600和体积分数4%、Re=800。In the present study,the convective heat transfer and entropy generation of R134a nanorefrigerant flow in microchannel are numerically investigated.The nano-powders include cupric oxide(CuO)and carbon nanotube(CNT),the volume fraction range is from 0 to 4%,and Reynolds number(Re)range is from 400 to 2,000.The results indicate that the convective heat transfer coefficient and frictional pressure drop increase with the increase of volume fraction and Re;when Re is 1,200,compared to pure R134a,the convective heat transfer coefficients of R134a-CuO and R134a-CNT nanorefrigerants with volume fraction of 4%are increased by 45.7%and 125.7%,respectively,while the frictional pressure drops are increased by 192.4%and 161.8%,respectively.With the increase of Re and volume fraction,the thermal entropy generation decreases while the frictional entropy generation increases;the minimum entropy generation for R134a-CuO and R134a-CNT nanorefrigerants occurs at conditions of 2%volume fraction combining Re=1,600,and 4%volume fraction combining Re=800,respectively.

关 键 词：纳米制冷剂 对流换热 熵产 微通道 数值模拟 

分 类 号：TK124[动力工程及工程热物理—工程热物理] TB64[动力工程及工程热物理—热能工程]