Non-equilibrium evaporation/condensation model

TL;DR

This paper introduces a new mathematical model for non-equilibrium evaporation and condensation, including boiling effects, with a numerical solution code demonstrating the importance of non-equilibrium modeling for accurate rate calculations.

Contribution

It presents a novel differential-algebraic system for non-equilibrium evaporation/condensation including boiling, and develops a numerical code to solve it.

Findings

Non-equilibrium models are necessary for accurate evaporation/condensation rates.

The system quickly approaches quasi-equilibrium but requires non-equilibrium modeling for precision.

Numerical calculations confirm the model's effectiveness across various initial conditions.

Abstract

A new mathematical model for non-equilibrium evaporation/condensation including boiling effect is proposed. A simplified differential-algebraic system of equations is obtained. A code to solve numerically this differential-algebraic system has been developed. It is designed to solve both systems of equations with and without the boiling effect. Numerical calculations of ammonia-water systems with various initial conditions, which correspond to evaporation and/or condensation of both components, have been performed. It is shown that, although the system evolves quickly towards a quasi equilibrium state, it is necessary to use a non-equilibrium evaporation model to calculate accurately the evaporation/condensation rates, and consequently all the other dependent variables.