Modelling high temperature salt condensation; Fick and Soret diffusion effects

Abstract

The need for developing models to understand the fouling mechanisms in heat exchangers arises from the enormous cost that this entails to the European Community (approximately 10,000 MECU per year). This paper is addressed to developing a general mathematical model based on local thermochemical equilibrium (LTCE), incorporating mass conservation constraints which allow for deposition. This calculation has been performed in an entirely novel way using a stochastic optimisation technique and can deal with complex multi-species, multi-phase systems involving non-ideal equations of states. The flux estimation is based on Fick and Soret diffusion effects in the chemically frozen boundary layer (CFBL). The physical properties of the system at various temperatures are computed with the help of the Chapman-Enskog theory for the Lennard-Jones (6–12) potential. We describe a novel probe which has been designed for the measurement of high temperature condensation.