Numerical study of heat and mass transfer enhancement for bubble absorption process of ammonia-water mixture without and with nanofluids

Abstract

This paper presents a detailed analysis of a combined heat and mass transfer enhancement by using binary nanofluid in NH3/H2O bubble absorption processes. A differential mathematical model of ammonia-water absorption has been developed on the basis of mass and energy balances and heat and mass transfer equations, in order to analyses the effects of binary nanofluid on ammonia absorption. A finite difference technique was employed to solve the numerical model. A parametric analysis was conducted to assess the effect of key parameters: the effective absorption rate, the concentration of nanoparticles, kinds of additives of nanoparticles, the bubble diameter, and the gas holdup on the performance of the absorber. As expected, the addition of nanoparticles enhances the absorption performance during the bubble absorption process. Also, it is found that the highest effective absorption ratio was reported for solution with copper. The concentration of nanoparticles has a significant effect on the absorber size.