不同小分子醇类对聚合物蓄冷剂影响的分子动力学模拟  

Molecular Dynamics Simulation of the Effects of Different Small Molecular Alcohols on Polymer Cold Storage

作　　者：陈有良 盛伟[1,2] 王蕊蕊 郑海坤 郝晓茹[1] CHEN Youliang;SHENG Wei;WANG Ruirui;ZHENG Haikun;HAO Xiaoru(School of Mechanical and Power Engineering,Henan Polytechnic University,Jiaozuo 454003,China;Hami Yuxin Energy Industry Research Institute,Hami 839000,China)

机构地区：[1]河南理工大学机械与动力工程学院,焦作454003 [2]哈密豫新能源产业研究院,哈密839000

出　　处：《工程热物理学报》2023年第6期1481-1490,共10页Journal of Engineering Thermophysics

基　　金：河南省自然科学基金项目(No.162300410112);河南省教育厅基金(No.21A470003);河南理工大学博士基金(No.B2021-37);哈密市科学研究与技术开发计划项目;新疆维吾尔自治区人才专项支持。

摘　　要：聚合物蓄冷剂是一种新型蓄冷材料,目前对于其性质尤其是微观机理研究较少。本文在等温-等压系综下采用分子动力学模拟方法研究了不同小分子醇类(乙二醇、甘油、丙二醇)对聚乙烯吡咯烷酮(PVP)、聚乙二醇(PEG)两种聚合物水溶液蓄冷剂在不同温度下的动力学特性,并从氢键分布与体系平衡态、径向分布函数、扩散系数等角度进行了分析。结果表明:温度对于蓄冷剂影响较大,温度越低,分子动能越小,分子运动越平缓,氢键结合力越大,体系黏度增大,扩散系数减小,有序性增强,进而完成由液相到固相的转变;在PEG-甘油-水体系中模拟相变温度为253.15 K附近,与实验值255.6 K吻合良好,当温度从293.15 K降至243.15 K时,PEG-乙二醇/甘油/丙二醇-水三种体系扩散系数分别降低了67.7%、69.1%、73.8%。研究结果对于筛选和制备高性能的复合蓄冷材料具有一定的参考价值和指导意义。Polymeric cold storage agent is a new type of cold storage material,and there have been few studies on its properties,especially its microscopic mechanism.In this paper,the molecular dynamics simulation method is used to study the kinetic characteristics of different small molecular alcohols(ethylene glycol,glycerin,propylene glycol)on polyvinylpyrrolidone(PVP)and polyethylene glycol(PEG)aqueous polymer refrigerant storage at different temperatures under isothermal isobaric ensemble,and the simulated system is analyzed from the perspectives of hydrogen bond distribution and system equilibrium state,radial distribution function and diffusion coeficient.The results show that the temperature has a great influence on the regenerator.As the temperature decreases,the molecular kinetic energy of the system decreases,the motion becomes smoother,the hydrogen bonding force increases,the viscosity of the system increases,the diffusion coefficient decreases,the orderliness increases and then the system completes the transition from liquid phase to solid phase;The simulated phase transition temperature in the PEG-glycerol-water system is around 253.15 K,which is in good agreement with the experimental value of 255.6 K.When the temperature decreases from 293.15 K to 243.15 K,the diffusion coefficients of PEG glycol/glycerol/propylene glycol water systems decrease by 67.7%,69.1%and 73.8%respectively.The research results have certain reference value and guiding significance for screening and preparing high-performance composite cold storage materials.

关 键 词：聚合物 蓄冷剂 氢键 分子动力学模拟 

分 类 号：TK124[动力工程及工程热物理—工程热物理] TK02[动力工程及工程热物理—热能工程]