摘要
用原始Pitzer模型、扩展的Pitzer模型、Pitzer-Simonson-Clegg模型、S-MSA模型和BET模型分别对LiCl-H2O,LiBr-H2O,CaCl2-H2O,Mg(NO3)2-H2O,MnCl2-H2O和Mn(NO3)2-H2O等六种不同体系的热力学性质进行描述,考察了各种模型的预测能力.结果表明原始Pitzer模型不能准确描述高浓电解质溶液的性质;扩展的Pitzer模型虽然能较准确地描述某些体系高浓度的热力学性质,但预测能力不足;Pitzer-Simonson-Clegg模型对高浓盐水体系热力学性质具有一定的预测能力,但拟合参数所用的最大浓度与溶解度相差很大时,外推饱和点的热力学性质则会出现较大偏差;S-MSA模型虽然可以将拟合参数的浓度范围扩大到饱和,但没有外推能力,而且需要溶液的密度数据,这限制了该模型的广泛应用;BET模型对这六种体系均体现出很强的预测能力,预测结果准确,且模型参数少,物理意义明确,该模型可用于熔盐水化物相变储能材料的设计.
Five widely used typical thermodynamic models were selected to describe and predict the thermodynamic properties of the six binary salt-water systems, LiCl-H2O, LiBr-H2O, CaCl2-H2O, Mg（NO3）2-H2O, MnCl2-H2O and Mn（NO3）2-H2O. The predicted results were compared with reliable experimental results, showing that the primitive Pitzer model has poor prediction ability. The extended Pitzer model, although can reproduce the thermodynamic properties of a binary system to a quite high salt concentration, shows weak extrapolation prediction ability. The Pitzer-Simonson-Clegg model can reproduce and predict thermodynamic properties of some binary systems with satisfactory results. However, when the salt concentration range used for the parameterization of the thermodynamic models is far less than the solubility limit, the Pitzer-Simonson-Clegg model can not give accurate property prediction of the saturated solution. S-MSA model can not give accurate thermodynamic property prediction of the saturated solution. Furthermore, the requirement of solution density for this model limits its application. The BET model, showing strong extrapolation ability in all six binary system, is worthwhile to be recommended for the application in theoretical design of phase change materials.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2008年第15期1815-1826,共12页
Acta Chimica Sinica
基金
国家863项目(No.2006AA05Z212)
973前期预研项目(No.2006CB708604)资助项目
关键词
相变储能材料
热力学模型
水的活度
溶解度
蒸汽压
phase change material
thermodynamic model
water activity
solubility
vapor pressure
