摘要
使用分子动力学模拟方法,在温度为200-280 K的NVT系综下,对纳米粒子-CO_(2)水合物复合体系进行模拟计算,研究了不同种类(Ag,Cu,Fe)、不同粒径(1.0 nm,1.5 nm,2.0 nm)的球形纳米粒子对水合物导热性能的影响,从体系构型、导热系数、纳米粒子运动速度等方面探究纳米粒子对水合物导热性能的强化机理.模拟结果表明,纳米粒子的加入,不影响水合物导热率与温度的相关性;与同温度下纯质CO_(2)体系相比,粒径相同时,Ag、Cu、Fe的复合体系导热增长率分别为25.6%-43.8%、19.4%-31.9%、6.9%-17.6%,纳米Ag导热增强效果最好;对于同一粒子,粒径越小,整体的导热能力越强,粒径1.0 nm、1.5 nm、2.0 nm的复合体系导热增长率分别为28.2%-39.8%、19.4%-31.9%和7.5%-17.1%.
The nanoparticles-CO_(2)hydrate composite systems were simulated under the NVT ensemble with temperature range of 200-280 K by using molecular dynamics simulations.The effects of spherical nanoparticles of different types(Ag,Cu,Fe)and different particle sizes(1.0 nm,1.5 nm,2.0 nm)on the thermal conductivity of hydrates were studied.The mechanism of strengthening the hydrates thermal conductivity by nanoparticles was explored from the aspects of system configurations,thermal conductivity,and nanoparticle movement speed.Simulation results show that the additions of nanoparticles do not affect the correlation between the hydrate thermal conductivity and the temperature.Compared with the pure CO_(2) system at the same temperature,when the particle size is the same,the thermal conductivity growth rates of Ag,Cu,Fe composite systems are respectively 25.6%-43.8%,19.4%-31.9%,6.9%-17.6%,and the thermal conductivity enhancement effect of Ag nanospheres is the best among the three nanoparticles.For the same particle,the smaller the particle size,the stronger the overall thermal conductivity.The thermal conductivity growth rates of the composite systems with particle sizes of 1.0 nm,1.5 nm and 2.0 nm are 28.2%-39.8%,19.4%-31.9%and 7.5%-17.1%,respectively.
作者
刘庭崧
刘妮
洪春芳
LIU Ting-Song;LIU Ni;HONG Chun-Fang(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering,Shanghai 200093,China)
出处
《原子与分子物理学报》
CAS
北大核心
2021年第6期71-76,共6页
Journal of Atomic and Molecular Physics
作者简介
刘庭崧(1996—),男,江苏南通人,硕士研究生,研究方向为水合物成核与生长分子模拟.E-mail:747867873@qq.com;通讯作者:刘妮.E-mail:ni-liu@hotmail.com。
