کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10150469 | 1663208 | 2018 | 42 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Unified presentation and comparison of various formulations of the phase stability and phase equilibrium calculation problems
ترجمه فارسی عنوان
ارائه یکپارچه و مقایسه فرمول های مختلف ثابت محاسبات فاز و تعادل فاز
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
مهندسی شیمی (عمومی)
چکیده انگلیسی
In this paper we present general formulations of the phase-equilibrium and phase-stability problems for multicomponent mixtures and verify that these formulations generalize the problems of phase-equilibrium and phase-stability at constant volume, temperature, and mole numbers (VTN-flash), at constant internal energy, volume, and mole numbers (UVN-flash), and at constant pressure, temperature, and mole numbers (PTN-flash). Furthermore, we develop a numerical method for solving the general formulation of phase-equilibrium problems. This algorithm is based on the direct minimization of the objective function with respect to the constraints. The algorithm uses a modified Newton-Raphson method, along with a modified Cholesky decomposition of the Hessian matrix to generate a sequence of states with decreasing values of the objective function. The algorithm was implemented in C++ and using generic programing we have a single, portable solver for all three flash formulations. Properties of the algorithm are shown on phase-equilibria problems of multicomponent mixtures in different specifications and with different levels of difficulty. Complexities and numerical performance of the individual flash formulations are discussed.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Fluid Phase Equilibria - Volume 476, Part B, 25 November 2018, Pages 61-88
Journal: Fluid Phase Equilibria - Volume 476, Part B, 25 November 2018, Pages 61-88
نویسندگان
TomáÅ¡ Smejkal, JiÅà MikyÅ¡ka,