Experimental and Numerical Simulation to Investigate the Effects of Membrane Fouling on the Heat and Mass Transfer

Nanoporous tubular ceramic membranes (TCMs) are commonly used to extract water vapor and to recover latent heat from flue gas in thermal power plants. Water vapor condenses on the surface of the outer wall of the TCM, and the generated condensate permeates the membrane and flows along with the coolant water within the membrane. With time and use, fouling cakes will gradually accumulate and adhere on the inner surface of the membrane wall because of different kinds of soluble salts in the coolant water, which have negative effects on the water recovery performance of the membrane. This paper describes experiments to analyze the effect of membrane use times (0h, 400h and 800h) on fouling cakes. The water recovery performance of the membrane with different use times is investigated experimentally and numerically using the commercial software FLUENT 14.5. Lastly, we evaluate the significance of multiple operational conditions on the water recovery process of ceramic membranes by using an ANOVA based on both the experimental and numerical results. The results showed that the water recovery rate of the membrane decreased by a maximum of 76.3% when its use time reached 800h. Furthermore, the original water vapor content of the gas plays a more critical role on the water recovery process compared to other operational parameters.