常压下固态KNO_2热力学性质的密度泛函理论研究  

Thermodynamic Properties of Cubic KNO_2 under Atmospheric Pressures: Density Functional Study

作　　者：彭强[1] 杨晓西[1,2] 丁静[3] 魏小兰[1] 陆建峰[3] 杨建平[1] 

机构地区：[1]华南理工大学化学与化工学院传热强化与过程节能教育部重点实验室,广州510640 [2]东莞理工学院广东省分布式能源系统重点实验室,东莞523808 [3]中山大学工学院,广州510006

出　　处：《计算物理》2013年第2期271-276,共6页Chinese Journal of Computational Physics

基　　金：国家重点基础研究发展计划(2010CB227103);国家自然科学基金(50930007);国家高技术研究发展计划项目(2012AA050604)资助

摘　　要：采用密度泛函理论结合准谐德拜模型研究常压下300～725 K间KNO2立方结构的热力学性质,重点分析常压下定压热容、定容热容、熵、德拜温度、体膨胀系数、平衡体积和体弹模量随温度的变化.结果显示,常压下计算的定压热容随温度的变化与实验数据符合较好,而计算的熵与实验数据相差较大.计算得到KNO2的平均体膨胀系数约为1.837 8×10-5K-1,常温下(300 K)KNO2的德拜温度约为667.13K.To understand performance of molten salt heat transfer and thermal storage in solar thermal power system, thermodynamic properties of cubic KNOz under atmospheric pressure and temperatures between 300 and 725 K are studied with density functional theory combined with a quasi-harmonic Debye model. Temperature dependence of isobaric heat capacity, isochoric heat capacity, entropy, Debye temperature, volume thermal expansion coefficient, equilibrium volumes and bulk modulus under ambient pressure are calculated. It shows that calculated isobaric heat capacities are in good agreement with experiments under ambient pressures. Both entropy vary greatly. The average volume thermal expansion coefficient-is 1. 837 8×10^-5K^-1 and Debye temperature is 667.13K at ambient temperatures, respectively.

关 键 词：KNO2 密度泛函理论 准谐德拜模型 热力学性质 

分 类 号：TK123[动力工程及工程热物理—工程热物理] O631[动力工程及工程热物理—热能工程]