Modelling and dynamic simulation of a large MSF plant using local phase equilibrium and simultaneous mass, momentum, and energy solver

Seawater desalination is an important method for producing fresh water, a critical resource in many areas of the globe. Multi-stage flash distillation (MSF) is a leading technology within the thermal desalination field. Mathematical modelling and simulation provides a means to enhance engineering and operation of complicated production plants. This paper presents a new method for one-dimensional modelling and dynamic simulation of thermal desalination processes. The approach combines the simultaneous mass, momentum, and energy solution, local phase equilibrium by Rachford-Rice equation, and rigorous calculation of the seawater properties as function of temperature, pressure and salinity. A brine recycling MSF plant was modelled as a case study, presenting advanced and unpublished simulated features and transients. The successful results suggest that the method presented is a competent approach for dynamic simulation of thermal desalination processes.