Abstract An accurate approximation for the Debye-Huckel limiting slopes based on the IAPWS (the International Association for the Properties of Water and Steam) equations for water was proposed. It is valid for T = 273.15 − 523.15 K and p = 0 − 100 MPa and uses one self-consistent formula and parameters set for all six coefficients. It uses a special extrapolation procedure for values below 273.15 K that is not dependent on equations of state for supercooled water and can be applied down to 173.15 K. The computations took only about 1% of the time that was required for the computations based on original IAPWS equations. Usage of the IAPWS-IF97 (IAPWS Industrial Formulation 1997) equation instead of the IAPWS95 equation for the water density is also discussed. The developed procedure was also applied to other popular equations for Debye-Huckel coefficients (by Archer and Wang and by Bradley and Pitzer). Tabulated IAPWS95 based values for the Debye-Huckel limiting slopes for T = 273 − 723 K , p = 0 − 100 MPa and their extrapolation down to 173 K are given.

中文翻译：

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基于IAPWS水状态方程的Debye-Hückel极限斜率计算和低温外推的快速方法

摘要 提出了基于 IAPWS（国际水和蒸汽性质协会）方程的精确逼近 Debye-Huckel 极限斜率。它对 T = 273.15 − 523.15 K 和 p = 0 − 100 MPa 有效，并对所有六个系数使用一个自洽公式和参数集。它对低于 273.15 K 的值使用特殊的外推程序，该程序不依赖于过冷水的状态方程，可以应用于低至 173.15 K。计算仅花费了基于原始计算所需时间的 1% 左右IAPWS 方程。还讨论了使用 IAPWS-IF97（IAPWS Industrial Formulation 1997）方程代替 IAPWS95 方程来计算水密度。开发的程序也应用于德拜-哈克尔系数的其他流行方程（由 Archer 和 Wang 以及 Bradley 和 Pitzer）。给出了 T = 273 - 723 K、p = 0 - 100 MPa 时德拜-休克尔极限斜率的基于 IAPWS95 的列表值及其向下推算至 173 K。