基于化学热力学的饱和指数模型求解方法的改进

Modification of solution method of the saturation index model based on the chemical thermodynamics

摘要: 饱和指数SI是反映水环境中矿物溶解/沉淀状态的重要参数,而水溶液中络合物的存在对SI值有很大的影响,因此正确计算络合物的含量,可提高水-岩作用SI模型的计算精度。依据化学热力学的基本理论,作者扩展了活度系数计算方程、优化了阀值的选取、并改进了输出结果。结合某工程实例,与传统算法做了比较,证明该模型的算法具有更好的稳定性和计算精度,结果亦与实际情况更相符。

Abstract: Saturation index(SI) is an important parameter to describe the water-rock interaction state,while complex has a significant influence on the state.It is possible to improve the accuracy of SI model by correctly evaluating the content of complex.According to the basic theory of chemical thermodynamics,a FORTRAN code was designed to calculate SI value for modifying solution method of saturation index model.It is proved that this model has better stabilization and precision.