A 3-D model based on computational fluid dynamic (CFD) approach was developed
to explore the effect of fluid dynamic conditions and combustion reactions
on oxygen transport, in which the distribution of parameters such as oxygen
partial pressure, temperature, velocity and oxygen permeability were
considered. After meshing the geometric model with Poly-Hexcore method, a
series of User Defined Functions (UDFs) written in C++ were compiled and
hooked to FLUENT to solve for oxygen permeation of dual-phase oxygen
transport membranes (OTMs). The results showed that oxygen permeability can
be improved by pressurizing the feed side or vacuuming the permeate side,
and the increased kinetic effect under evacuation conditions can increase
the oxygen permeability by 69.85% at a vacuum pressure of 10kpa and by
270.94% at 90kpa. Due to the phenomenon of differential concentration
polarization?the effect of oxygen concentration on oxygen permeability is
more significant when the oxygen concentration on the feed side is lower
than 0.17. Combustion reaction of CH4 promotes oxygen permeation, and the
effect of the gap height between the fuel inlet and membrane is determined
by several trade-off factors including momentum effects, reaction rate and
temperature?and optimal oxygen permeability is achieved with a gap height of
3mm.