利用形状因子对应态原理构建卤化盐的黏度预测模型

Using the Corresponding States Principle to Build the Viscosity Model of Molten Alkali Halide Salts

针对已有的熔融盐形状因子对应态原理黏度模型预测精度较低的问题,改进了形状因子的计算方法,其中熔融盐临界温度通过文献获得,临界压力通过估算式计算得到,参数a、b通过参考流体的黏度与对应熔融盐的黏度求解得到。在忽略了熔融盐密度对黏度影响的基础上,建立了熔融盐黏度预测模型。以NaCl熔融盐为参考流体,对16种卤化盐的黏度进行预测,并将预测结果与文献报道的158个黏度数据进行对比,结果表明本文模型计算的预测值的最大平均偏差小于0.70%,最大偏差小于1.64%。本文建立的熔融盐黏度预测模型具有所需输入参数少、预测精度高和使用便利的优点,能够有效扩展现有熔融盐黏度数据的温度范围,可供科研和工程设计参考。

An improved approach for calculating the empirical shape factors is proposed to solve the problem that the prediction accuracy of existing extended corresponding states model for predicting viscosity of molten salts is low.The value of the critical temperature is obtained from the data reported in literature,the value of critical pressure is calculated by an estimation formula,and the values of parameters a and b are obtained via two groups of viscosity data of the reference fluid and the specific molten salt.On the basis of ignoring the influence of molten salt density on the viscosity,a prediction model of molten salt viscosity is established.The performance of the model to predict the viscosity of 16 kinds of alkali halide salts is examined with molten sodium chloride as the reference fluid.Results show that the maximum absolute average deviation and the maximum relative deviation between the calculated viscosity value and literature viscosity value are less than 0.70%and 1.64%,respectively.The model has the advantages of less input parameters,high prediction accuracy and convenient use.It can effectively expand the temperature range of existing viscosity data of molten salts by prediction,and can serve as reference for scientific research and engineering design.