Experimental study on differences of heat and mass flux on opposite side of a 10-nm nanoporous ceramic membrane tube

Abstract

A nanoporous ceramic membrane tube (CMT) is able to extract water vapor and latent heat from gas mixture, such as flue gas exhausted from thermal power plant, because of its excellent permselectivity and heat-exchange capacity. However, due to the effect of the gravity force on condensation film formation and condensate permeation process, the water and heat-recovery performance on top and bottom parts of a horizontal CMT may be distinct. In this study, a corresponding experiment was performed to verify and research the phenomenon by installing six equidistant and symmetrical measuring points at top and bottom parts of the experimental CMT module, respectively. According to the experimental data, the local temperature of cooling water on top (Tc,l,t) and bottom (Tc,l,b) parts of CMT module exhibited a distinct changing tendency, and the maximum temperature difference (ΔTc) could approach 2.68 °C. Typically, the effects of gravity force on condensation film was negligible, while the permeation capacity of condensate was influenced by gravity force apparently. Moreover, most of condensate (92.24% maximally) was generated during the normal condensation process, merely a small proportion of condensate was produced by the capillary condensation process. This paper is useful for horizontal membrane type gas-water technology improvement.