Understanding the operation of industrial MSF plants Part I: Stability and steady-state analysis

Abstract

This paper deals with expanding the knowledge about the operation of multi-stage flash (MSF) desalination processes. This was achieved through stability and steady-state analysis conducted on a simulated model for the MSF plant. The model was developed and validated using steady-state plant data. The stability analysis was based on the eigenvalues of the linearized version of the model, which revealed that the MSF plant is normally internally stable. The steady-state analysis investigated the effect of each process input on the process key variables. The combined effect of two inputs at a time was also examined. The steady-state analysis was found useful to locate economically favorable operating conditions and to locate conditions at which undesirable brine level may occur. The steady-state analysis is also useful to study the controllability of the MSF plant, which helps in enhanced control design.