摘要
以正十四烷(C14)为基液燃油,十六烷基三甲基溴化铵(Cetyltrimethyl Ammonium Bromide,CTAB)为表面活性剂,采用两步法配制CNT(Carbon Nanotubes)和CeO2纳米燃油,搭建悬浮液滴蒸发装置,研究纳米粒子质量分数、粒径及种类对燃油蒸发速率的影响。结果表明,纳米燃油液滴蒸发遵循D2定律。温度较低时,纳米燃油液滴表面张力对蒸发速率的不利影响更加显著,纳米粒子质量分数越大,表面张力越大,其蒸发速率随着纳米粒子质量分数增加而降低;而温度较高时,纳米粒子在基液中的布朗运动加强,导热效率更高,有利于促进燃油液滴蒸发过程,其蒸发速率随着纳米粒子质量分数增加而增大。相同质量分数下,在单位体积纳米燃油中,小粒径纳米粒子数量更多,传热界面更多,更有利于热量传递,因此纳米燃油蒸发速率随纳米粒子粒径的增大而降低。此外,CNT具有比CeO2更好的导热性和更小的密度,CNT纳米粒子促进燃油液滴蒸发的效果更加明显。
Via the two steps method,CNT(Carbon Nanotubes)and CeO2 nano-fuel blends were prepared,in which the N-tetradecane(C14)served as the base fuel and the CTAB(Cetyltrimethyl Ammonium Bromide)worked as the surfactant.The evaporation experiments were performed in an appropriative device for pendant droplets,in order to explore the effects of mass fractions,types and sizes of nanoparticles on the evaporation characteristics.It is revealed that the evaporation of nano-fuel droplets follows the D2-law.At low temperature,the surface tension of nano-fuel droplets has a more significant adverse effect on the evaporation rate.The surface tension of the nano-fuel droplets increases as the mass fraction of the nanoparticles increases,slowing down the evaporation rate.However,the Brownian motion is always intensive at high temperature,and the thermal conductivity of the nano-fuel is increased with the growth of the mass fraction of the nanoparticles,contributing to the increment of evaporation rates.At the same mass fraction,nano-fuel with smaller particle size contains more nanoparticles in the unit volume and possesses more interface,which is more conducive to heat transfer.Therefore,the evaporation rates decrease with the increase of the particle size of the nanoparticles.In addition,compared with CeO2,CNT nanoparticles have better thermal conductivity and lower density,the role of CNT nanoparticles in enhancing the droplet evaporation is more pronounced.
作者
郭冬梅
梅德清
陈志宇
孙潮
袁银男
GUO Dong-Mei;MEI De-Qing;CHEN Zhi-Yu;SUN Chao;YUAN Yin-Nan(School of Automotive and Traffic Engineering,Jiangsu University,Zhenjiang 212013,China;College of Energy,Soochow University,Suzhou 215006,China)
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2020年第12期3152-3159,共8页
Journal of Engineering Thermophysics
基金
国家自然科学基金项目(No.51876082,No.51876133)。
关键词
纳米粒子
纳米燃油
液滴
蒸发
nano-particles
nano-fuel
droplet
evaporation
作者简介
郭冬梅(1996-),女,硕士研究生,主要从事纳米燃油液滴蒸发研究;通信作者:梅德清,副教授,E-mail:meideqing@ujs.edu.cn。
