高温无机晶体材料比热容的双参数预测方法  

A two-parameter prediction method for specific heat capacity of high-temperature inorganic crystal materials

作　　者：魏小林[1,2] 李腾 李博[1] 孙岑[1,2] WEI Xiaolin;LI Teng;LI Bo;SUN Cen(State Key Laboratory of High Temperature Gas Dynamics,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China;School of Engineering Science,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院力学研究所高温气体动力学国家重点实验室,北京100190 [2]中国科学院大学工程科学学院,北京100049

出　　处：《洁净煤技术》2020年第6期118-125,共8页Clean Coal Technology

基　　金：国家重点研发计划资助项目(2016YFB0601501);国家自然科学基金资助项目(51736010)。

摘　　要：高温固体比热容是工业流程设计中常用的热物性数据,但通过实测获取温度达数千度的固体比热容比较困难,因此许多含有复杂晶格的固体经常只存在有限温度范围内的比热容测量数据。爱因斯坦模型和德拜模型可以适用于简单的单原子晶体或某些双原子晶体比热容预测,但多原子复杂晶格固体的德拜温度或爱因斯坦温度难以准确获得,使得这些模型难以准确预测这些固体比热容。因此,利用统计热力学方法,针对含多原子复杂晶格固体比热容的测试困难问题,提出一种高温固体比热容的双参数预测方法;该方法将多原子固体的晶格振型分为声学支与光学支,假设这些固体的单个晶格原胞具有唯一的德拜特征温度ΘD和爱因斯坦温度ΘE;通过晶体学的基本参数获得德拜特征温度ΘD,通过固体比热容的有限试验数据或简单物质的热物性,反算出复杂晶格固体的爱因斯坦温度ΘE;然后利用这2个主要影响参数预测高温固体的理论比热容。采用该双参数预测方法对典型单原子、双原子与多原子晶体的比热容进行了预测计算,计算结果与试验数据对比验证表明,该方法误差主要在温度拐点和高温区附近,在宽范围变化的温度区间内比热容的预测误差小于5%,有望为流程工业的固体热物性数据提供一种简单可靠的确定方法。High-temperature solid specific heat capacity is commonly used thermal property data in industrial process design,but it is difficult to obtain these data of solid with the temperature of thousands of degrees by actual measurement.Therefore,many solids with complex lattice often only have the measurement data of specific heat capacity within a limited temperature range.The Einstein and Debye models can be applied to simple mono-atomic crystals or some bi-atomic crystals for specific heat capacity prediction.However,it is difficult to accurately obtain the Debye and Einstein temperatures of polyatomic intricate lattice solids,making it difficult for Einstein and Debye models to predict these solids'specific heat capacity accurately.In this paper,based on the statistical thermodynamic method,and to determine the specific heat capacity for a solid with multiple atoms,a two-parameter prediction method for the high-temperature solid's specific heat capacity was proposed.In this method,the solid lattice vibration mode is divided into acoustic and optical branches.It is assumed that a single lattice cell has a unique Debye characteristic temperatureΘD and Einstein temperatureΘE.Moreover,the Debye characteristic temperatureΘD is obtained through the basic parameters of crystallography.The Einstein temperatureΘE of intricate lattice solid is calculated backward through the limited experimental data of the specific heat capacity of the solid or the thermal properties of simple substance.Then the solid's theoretical specific heat capacity can be predicted utilizing these two parameters at different temperatures.The two parameter prediction method is used to predict the specific heat capacity of typical monoatomic,diatomic and Polyatomic Crystals.The comparison between the calculation results and the experimental data results show that the two-parameter prediction method's error is mainly at the temperature inflection point and the high-temperature region.The prediction error of the specific heat capacity in the wide ran

关 键 词：高温固体 比热容 双参数 预测方法 

分 类 号：TQ172[化学工程—水泥工业] TK17[化学工程—硅酸盐工业]