Experimental investigation of the effect of magnetic field on vapour absorption with LiBr–H2O nanofluid

Abstract

This work presents a new approach for further research in enhancing vapour absorption rate and understanding the enhancement mechanism in the process. The experimental study explored enhancing vapour absorption from using an external magnetic field to induce slip movement of nanoparticles in a nanofluid. The experiment were carried out in an adiabatic falling film absorber with a mixture of LiBr–H2O solution and Iron (III) nanopowder, <50 nm at the mass fraction 0.17% in the fluid. The experimental results show that the vapour absorption rates increased by 17.6% and 4.9% with the nanofluid circulating at 3 L min−1 and 3.5 L min−1, respectively, compared with that with the base fluid. A further increase was observed when the movement of the nanoparticles in the fluid was influenced by an external magnetic field. The vapour absorption rates obtained with the magnetic field in place were 1.58 times and 1.32 times higher than that without it for the nanofluid circulating at 3.5 L min−1 and 3.0 L min−1, respectively.A further analysis on the experimental data suggested that the enhancement of vapour absorption rate was associated with the frequency of the nanoparticles movement. A high frequency movement of the nanoparticles helped the vapour absorption process in our experimental tests.