论文标题
使用音量函数和还原方法快速多组分相分解计算
Rapid multi-component phase-split calculations using volume functions and reduction methods
论文作者
论文摘要
我们提出了一个新的快速，强大方法的家庭，用于计算在等含量iSothermal（pt-flash），等温液（vt-flash），Isenthalpic-Isobaric（hp-flash）和Isoenerenergetic-Isochorgetic-Isochocic（uv-flash）条件下的蒸气平衡。该框架是通过根据来自Helmholtz自由能的最近引入的体积函数的摩尔比值有效降低空间中多组分混合物的相平衡条件来提供的。提出的算法实现可以完全利用牛顿法与分析雅各布矩阵的最佳二次收敛。本文为一般的状态立方方程提供了所有必需的精确分析表达式。计算结果证明了新方法的有效性和效率。与常规方法相比，所提出的缩小空间迭代会导致相当大的速度以及改善的鲁棒性和在多组分混合物的旋转和共存曲线附近的稳健性和更好的收敛行为，其中还原方法的预处理是最有效的。
We present a new family of fast and robust methods for the calculation of the vapor-liquid equilibrium at isobaric-isothermal (PT-flash), isochoric-isothermal (VT-flash), isenthalpic-isobaric (HP-flash), and isoenergetic-isochoric (UV-flash) conditions. The framework is provided by formulating phase-equilibrium conditions for multi-component mixtures in an effectively reduced space based on the molar specific value of the recently introduced volume function derived from the Helmholtz free energy. The proposed algorithmic implementation can fully exploit the optimum quadratic convergence of a Newton method with the analytical Jacobian matrix. This paper provides all required exact analytic expressions for the general cubic equation of state. Computational results demonstrate the effectivity and efficiency of the new methods. Compared to conventional methods, the proposed reduced-space iteration leads to a considerable speed-up as well as to improved robustness and better convergence behavior near the spinodal and coexistence curves of multi-component mixtures, where the preconditioning by the reduction method is most effective.
