MWCNT-H_2O纳米流体对静态真空闪蒸制冰实验的影响  

Effect of ice-making for static vacuum flash system with MWCNT-H_2O nanofluid

作　　者：王章飞 章学来[1] 贾潇雅[1] 甘伟 韩兴超 陈跃 WANG Zhangfei;ZHANG Xuelai;JIA Xiaoya;GAN Wei;HAN Xingchao;CHEN Yue(Institute of Cool Storage Technology,Shanghai Maritime University,Shanghai 201306)

机构地区：[1]上海海事大学蓄冷技术研究所,上海201306

出　　处：《化工进展》2018年第7期2531-2538,共8页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(51376115);上海海事大学研究生学术新人培育项目

摘　　要：在蒸馏水中加入多壁碳纳米管(MWCNT)纳米粒子,选用亲水性非离子型表面活性剂TNWDIS为分散剂。经过超声波震荡,配制分散均匀稳定的MWCNT-H_2O纳米流体。利用静态真空闪蒸实验台,设定系统压力为100Pa,研究在吸附作用下多壁碳纳米管纳米粒子浓度、粒径、TNWDIS与MWCNT配比对闪蒸制取冰浆实验的影响。结果表明,多壁碳纳米管的加入可消除闪蒸制冰的相变蓄冷阶段、缩短液相降温时间使流体更早出现过冷现象;20~40nm粒径的MWCNT纳米粒子使用TNWDIS进行分散,质量分数范围在0.075%~0.15%时多壁碳纳米管纳米流体分散均匀稳定、达到最佳效果,其中质量分数为0.1%的纳米流体最大降低水的过冷度达62.2%;过冷度随着MWCNT纳米粒子粒径的增大而升高,闪蒸率基本维持在40%,但含冰率呈现非线性变化;20~40nm粒径的MWCNT纳米粒子使用TNWDIS配制成质量分数为0.1%的纳米流体,TNWDIS与MWCNT的分散配比建议采用0.5∶1,过冷度基本维持在2℃。Multi-walled carbon nanotube（MWCNT）nanoparticles were added into distilled water with hydrophilic TNWDIS of nonionic-type as surfactant. In order to get the stable homogeneous dispersions of MWCNT-H2O nanofluid,ultrasonic generator was used. Under the condition of 100 Pa and adsorption,the effects of nanofluid for different mass fractions,particle sizes of MWCNT and different ratios between MWCNTTNWDIS on static vacuum flash characteristics of ice-making were studied. The results showed that the addition of MWCNT can eliminate the stage of phase-change and shorten the cooling time at the stage of liquid phase. So the supercooling phenomenon appeared earlier. The 20—40 nm MWCNT-H2O nanofluid which the concentration ranges from 0.075% to 0.15% can be well-distributed by TNWDIS. When the concentration of MWCNT was 0.1%,the supercooling degree of water decreased by 62.2%,which reached the maximum reduction. The supercooling degree increased with the increase of particle size,while the flash evaporating rate remained at 40%. However,ice packing factor is varied nonlinearly. The optimal dispersive proportion of TNWDIS and 20—40 nm MWCNT is 0.5∶1. Under this dispersive proportion,the supercooling degree of 0.1% MWCNT-H2O nanofluids remained at 2℃.

关 键 词：纳米粒子 吸附 静态制冰 含冰率 闪蒸率 相变 

分 类 号：TK02[动力工程及工程热物理]