Diverse engineering fields require flash calculations like isothermal flash, isenthalpic flash, and isentropic flash. They can be cast as minimization of a thermodynamic state function and solved by Michelsen's Q‐function approach. Flash calculations for open systems, that is, systems where chemical potentials are specified instead of the mole numbers for some components, also belong to this scope. By analyzing the construction of Q‐functions through Legendre transforms, we extend this approach to the flash for open systems in the absence or presence of chemical reactions, resulting in general formulations for various specifications. For systems without reactions, the classical framework using mole numbers as independent variables is employed; for those with reactions, the modified‐RAND framework is employed. We present examples for open systems at constant temperature and pressure. Using the Q‐function minimization, we can solve multicomponent nonreactive or reactive systems at a specified chemical potential with quadratic convergence over a wide range of conditions.

中文翻译：

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在不存在或存在化学反应的情况下，基于状态函数的开放系统闪存规范

各种工程领域都需要进行等温闪光，等焓闪光和等熵闪光等闪光计算。可以将它们转换为热力学状态函数的最小化，并通过迈克尔逊的Q函数方法求解。对于开放系统（即指定了化学势而不是某些组件的摩尔数的系统）的Flash计算也属于此范围。通过分析Q的构造通过Legendre变换的功能，我们将这种方法扩展到在没有化学反应或不存在化学反应的情况下，用于开放系统的Flash，从而得到各种规格的通用配方。对于没有反应的系统，采用摩尔数作为自变量的经典框架。对于那些有反应的人，使用修改后的RAND框架。我们以恒定温度和压力下的开放系统为例。使用Q函数最小化，我们可以在指定的化学势下求解多组分非反应性或反应性系统，并且在宽范围的条件下都具有二次收敛性。