粗糙度对微细通道纳米流体临界热流密度(CHF)和不稳定性的影响

doi:10.16085/j.issn.1000-6613.2017-0523

摘要/Abstract

摘要： 分别以去离子水和质量分数为0.3%的Al₂O₃-H₂O纳米流体为实验工质，在水力直径为1.24mm的矩形微细通道内进行饱和流动沸腾传热实验研究。首先运用酸性抛光技术对矩形微细通道的壁面粗糙度进行处理，再采用SFS法获得壁面粗糙度的显微图像，然后借助MATLAB对图像进行灰度化处理，从而获得粗糙度分别为25.3、38.7、51.2的3种实验矩形微细通道。对比研究了去离子水和0.3% Al₂O₃-H₂O（质量分数）纳米流体在饱和流动沸腾传热过程中不同壁面粗糙度对临界热流密度（CHF）和纳米流体流动不稳定性的影响。研究结果表明：相同工况下，0.3% Al₂O₃-H₂O纳米流体的CHF比去离子水可提高18.37%~226.28%；随着壁面粗糙度的增大，两种工质的CHF均略有增大，但相比去离子水，0.3% Al₂O₃-H₂O纳米流体CHF随壁面粗糙度增大而增大的趋势更为明显；通过对大量实验数据综合评估分析，发现微细通道壁面粗糙度的增大会使微细通道内流体流动的不稳定性增大。

关键词: 微细通道, 纳米流体, 表面粗糙度, 临界热流密度, 不稳定性

Abstract: Saturated flow boiling heat transfer in rectangular microchannels with a hydraulic diameter of 1.24mm was experimentally investigated. Deionized water and 0.3% Al₂O₃-H₂O nanofluid were selected respectively as the working fluids. Rectangular microchannels' surface roughness was disposed firstly by acidic polishing process,further sonic frequency system(SFS) method was adopted to obtain the microscopic images of surface roughness,and then these images were gray-scale processing by means of MATLAB. Accordingly,three experimental rectangular microchannels whose surface roughness was 25.3、38.7 and 51.2 respectively were acquired. Contrastive study on the effect of different surface roughness on nanofluid critical heat fluxes(CHF)and instability in the process of saturated flow boiling heat transfer of deionized water and 0.3%Al₂O₃-H₂O nanofluid was carried out. Results indicated that under the same experimental conditions,the CHF of 0.3% Al₂O₃-H₂O nanofluid can be increased by 18.37%-226.28% than deionized water. With the increase of surface roughness,the CHF of both of them increases slightly,but the rising tendency of 0.3%Al₂O₃-H₂O nanofluid shows more obvious.Through the comprehensive evaluation and analysis of massive experimental data,it was found that the increase of microchannels' surface roughness can make the instability of fluid in the microchannels increase.

Key words: microchannel, nanofluid, surface roughness, critical heat fluxes(CHF), instability

中图分类号:

TK124

罗小平, 李海燕. 粗糙度对微细通道纳米流体临界热流密度(CHF)和不稳定性的影响[J]. 化工进展, 2017, 36(11): 3947-3954.

LUO Xiaoping, LI Haiyan. Effect of surface roughness on nanofluid critical heat fluxes (CHF) in rectangular microchannels and instability[J]. Chemical Industry and Engineering Progress, 2017, 36(11): 3947-3954.

参考文献

[1] TUCKERMAN D B,PEASE R F W.High-performance heat sinking for VLSI[J]. IEEE Electron Device Letters,1981,2(5):126-129.
[2] 葛洋,姜未汀.微通道换热器的研究及应用现状[J].化工进展,2016,35(s1):10-15. GE Yang,JIANG Weiting.Study and application of microchannel heat exchanger[J].Chemical Industry and Engineering Progress,2016,35(s1):10-15.
[3] 高广超,张鑫,李超.换热器的研究发展现状[J].当代化工研究,2016(4):83-84. GAO Guangchao,ZHANG Xin,LI Chao.Research and development of heat exchanger[J].Contemporary Chemical Industry Research,2016(4):83-84.
[4] WANG H,CHEN Z,GAO J. Influence of geometric parameters on flow and heat transfer performance of microchannel heat sinks[J]. Applied Thermal Engineering, 2016,107:870-879.
[5] 张瑞达, 罗小平, 王维. 微槽道纳米流体饱和沸腾CHF特性研究[J].低温与超导,2013,41(6):75-80. ZHANG Ruida,LUO Xiaoping,WANG Wei. Studies on CHF characteristics of nanofluid saturated boiling in microchannels[J].Chinese Journal of Low Temperature and Superconductivity, 2013,41(6):75-80.
[6] 唐杨.微槽道中磁流体的CHF特性研究[D].广州:华南理工大学,2011. TANG Yang. CHF characteristics of magnetic fluid in microchannel[D]. Guangzhou:South China University of Technology,2011.
[7] 陈志静,罗小平.竖直微槽道内沸腾换热CHF实验研究[J].低温与超导,2012,40(3):40-44. CHEN Zhijing,LUO Xiaoping.Study on boiling heat transfer CHF in vertical microchannels[J]. Journal of Low Temperature and Superconductivity,2012,40(3):40-44.
[8] 张霖,罗小平.微细通道纳米制冷剂压降波动特性研究[J].低温工程,2016(3):51-56. ZHANG Lin,LUO Xiaoping.Microchannel nanorefrigerant pressure drop characteristics of the study[J].Low Temperature Engineering,2016(3):51-56.
[9] KHARANGATE C R,O'Neill L E,MUDAWAR I. Effects of two-phase inlet quality,mass velocity,flow orientation,and heating perimeter on flow boiling in a rectangular channel:Part 2-CHF experimental results and model[J].International Journal of Heat & Mass Transfer,2016,103:1280-1296.
[10] KIM S M, MUDAWAR I.Review of two-phase critical flow models and investigation of the relationship between choking, premature CHF,and CHF in micro-channel heat sinks[J]. International Journal of Heat & Mass Transfer,2015,87:497-511.
[11] BALASUBRAMANIAN K,LEE P S, JIN L W, et al.Experimental investigations of flow boiling heat transfer and pressure drop in straight and expanding microchannels——a comparative study[J]. International Journal of Thermal Sciences,2011,50(12):2413-2421.
[12] BALASUBRAMANIAN K,JAGIRDAR M, LEE P S,et al.Experimental investigation of flow boiling heat transfer and instabilities in straight microchannels[J].International Journal of Heat & Mass Transfer,2013,66:655-671.
[13] QUAN X,DONG L,CHENG P.A CHF model for saturated pool boiling on a heated surface with micro/nano-scale structures[J]. International Journal of Heat & Mass Transfer,2014,76(6):452-458.
[14] KIM J,JUN S,LAKSNARAIN R, et al.Effect of surface roughness on pool boiling heat transfer at a heated surface having moderate wettability[J].International Journal of Heat & Mass Transfer,2016,101:992-1002.
[15] 张艳红.铝制品化学抛光新工艺的研究[D].太原:山西大学,2009. ZHANG Yanhong.Study on chemical polishing of aluminum products[D].Taiyuan:Shanxi University,2009.
[16] 郭美甜,张晓珊,孙甜,等.6061铝合金碱性抛光液及工艺的研究[J]. 科技与创新,2016(19):75-76. GUO Meitian,ZHANG Xiaoshan,SUN Tian,et al. 6061 aluminum alloy alkaline polishing liquid and technology research[J]. Technology and Innovation,2016(19):75-76.
[17] 张志航.基于小波分析的微细电火花线切割表面三维粗糙度评定研究[D].哈尔滨:哈尔滨工程大学,2012. ZHANG Zhihang.Study on 3D roughness evaluation of micro-EDM cutting surface based on wavelet analysis[D]. Harbin:Harbin Engineering University,2012.
[18] 刘斌,冯其波,匡萃方.表面粗糙度测量方法综述[J].光学仪器,2004,26(5):54-58. LIU Bin,FENG Qibo, KUANG Cuifang.Review of surface roughness measurement methods[J].Optics,2004,26(5):54-58.
[19] 王健全,田欣利,郭防,等. 基于灰度信息的工程陶瓷磨削表面粗糙度评定[J].装甲兵工程学院学报,2011,25(3):86-90. WANG Jianquan,TIAN Xinli,GUO Fang,et al.Evaluation of grinding surface roughness of engineering ceramics based on gray level information[J].Journal of Armored Force Engineering College,2011,25(3):86-90.
[20] 李新芳,朱冬生. 纳米流体传热性能研究进展与存在问题[J].化工进展,2006,25(8):875-879. LI Xinfang,ZHU Dongsheng. Study on progress and existing problems of heat transfer performance of nanofluid[J].Chemical Industry and Engineering Progress,2006,25(8):875-879.
[21] 彭小飞,俞小莉,夏立峰,等. 纳米流体悬浮稳定性影响因素[J].浙江大学学报工学版,2007,41(4):577-580. PENG Xiaofei,YU Xiaoli,XIA Lifeng,et al. Influencing factors of nanofluid suspension stability[J]. Journal of Zhejiang University Engineering Edition,2007,41(4):577-580.
[22] 徐立,李玉秀,徐进良,等. 微通道中纳米流体流动沸腾换热性能研究[J].高校化学工程学报,2011,25(4):559-564. XU Li,LI Yuxiu,XU Jinliang,et al. Study on boiling heat transfer performance of nanofluids in microchannels[J]. Journal of Chemical Engineering of Chinese Universities,2011,25(4):559-564.
[23] AHN H S,KIM H,JO H J,et al. Experimental study of critical heat flux enhancement during forced convective flow boiling of nanofluid on a short heated surface[J].International Journal of Multiphase Flow,2010,36(5):375-384.
[24] 赵亚溥.表面与界面物理力学[M].北京:科学出版社,2012:175. ZHAO Yapu.Surface and interface physical mechanics[M].Beijing:Science Press,2012:175.