COMPARISON OF HEAT AND MASS TRANSFER CHARACTERISTICS OF ABSORPTION OF R134A IN DMAC AND DMF FOR A FALLING FILM HORIZONTAL TUBE ABSORBER

摘要

The present work is a comparative study of heat and mass transfer behaviour during the absorption of R134a (1, 1, 1, 2 Tetrafluroethane) vapour into absorbents, DMAC (N, N-Dimethylacetamide) and DMF (N, N-Dimethylformamide). Initially, the heat and mass transfer characteristics for absorption of R134a into DMF for a falling film horizontal tubular absorber have been investigated by employing a two-dimensional numerical technique. The related governing equations are solved using a developed computer code in MATLAB. Then, a comparison of absorption characteristics of R134a-DMAC and R134a-DMF is made. For the mean value of operating parameters considered, the R134a-DMF solution absorbs more due to higher diffusion coefficient value of DMF than DMAC. The mass transfer coefficient is observed to decrease at a steeper rate at the entrance of the first tube for both working fluids, after which gradual decrease in the mass transfer coefficient is observed further downstream.