Heat and Mass Transfer Enhancement in Absorption of Vapor in Laminar Liquid Film by Adding Nano-Particles

In this paper, a numerical study was performed. The effect of nanoparticles on the absorption of vapor into a liquid film of lithium bromide aqueous solution flowing down over a cooled vertical channel is examined. The present model uses the numerical finite volume method to solve the parabolic governing equations for two-dimensional and laminar flow. In this model, the cooling water flows countercurrent to a solution of concentrated lithium bromide mixed with the nanoparticles. The water vapor is then absorbed at the interface of the absorbent film and diffused into the binary nanofluid (water-LiBr+nanoparticles). The numerical results indicate that the mass and heat transfer in binary nanofluids are enhanced more than that in base fluid and the highest absorption mass flux is observed by adding argent (Ag) nanoparticles. The results of the effects of operating conditions show that the effectiveness of the nanofluid becomes higher than that with the base fluid when the Reynolds number and inlet concentration are lower and when the inlet temperature solution and inlet pressure are higher.

Keywords:

Heat transfer , Mass transfer , Enhancement , Falling film , Absorption process , Nanoparticles , Water , Lithium bromide , Numerical simulation