Multiphase modeling of heat and mass transfer inside transport membrane condenser (TMC) tube bundle

Abstract

Transport membrane condenser (TMC) technology employs nanoporous ceramic membrane as a tubular heat-exchanger element to recover water vapor mass and related latent and sensible heat from flue gasses. In this study, a multiphase modeling approach using the volume of fluid (VOF), species transport, and Lee phase change models coupled with Darcy's law was proposed for modeling the heat and mass transfer inside the TMC tube bundle. The multiphase model results agree better with related experimental results than the single-phase model in terms of the outlet flue-gas temperature and condensation rate. Under different operating conditions, the modeling results showed that the condensation inside the flue gas domain was between 21% to 81% of the amount of water vapor that exists in the inlet flue gas, as compared to 7% to 49% of the reported experimental data. A parametric study revealed that an increase in the Reynolds number reduces the condensation rate and the condensation percentage while increasing the inlet water temperature reduces the condensation rate and increases the outlet flue gas temperature. Based on the observed and monitored flow pattern in the nanoporous ceramic membrane, the multiphase model can predict phase change and water transport on the TMC wall and more than 60% of water transport occur in the first half of the nanoporous membrane and within the first five seconds of the flow.