ID 325

Modeling high-pressure multicomponent droplet vaporization using quadrature moment methods with delumping and the Peng-Robinson equation of state

 

Abstract:

A computationally efficient droplet vaporization model using quadrature moment methods with delumping has been developed to investigate the effects of non-ideal vapor-liquid equilibrium (VLE) on a vaporizing multicomponent droplet exposed to high ambient pressure. The previously developed Direct Quadrature Method of Moments (DQMoM) with delumping and the Coupled Algebraic-Direct Quadrature Method of Moments (CA-DQMoM) with delumping are computationally efficient continuous thermodynamic approaches which solve for every discrete species within a multicomponent droplet at a fraction of the computational cost of full discrete component models. Although previous quadrature moment methods have been shown to be both accurate and computationally efficient, the approaches were limited to modeling ideal mixtures using Raoult’s law. In this study, these modeling approaches are extended to non-ideal mixtures using the cubic Peng-Robinson equation of state, and it is shown that DQMoM, CA-DQMoM and their corresponding delumping methods remain applicable. The results demonstrate that quadrature moment methods and delumping maintain accuracy and improve computational efficiency relative to discrete component models when modified with the non-ideal VLE equations. For high pressure applications, it is shown that the Raoult’s law and Peng-Robinson models deviate significantly, demonstrating the importance of accounting for the non-ideality of vapor-liquid equilibrium. The extended applicability of quadrature moment methods with delumping using the Peng-Robinson equation of state shows the promise of these methods to accurately model multicomponent droplet vaporization for a wide range of practical applications at minimal computational cost.