CFD heat and mass transfer studies in a R134a-DMF bubble absorber with swirl flow entry of R134a vapour

摘要

Study of absorber for heat and mass transfer analysis is essential to improve the performance of Vapour absorption refrigeration system (VARS). Tangential injection of refrigerant gas into liquid solution in a bubble absorber increases the heat and mass transfer characteristics by following rotary and translation path. In this study, a vertical absorber is considered for heat and mass transfer studies with refrigerant, R134a (1,1,1,2 - Tetrafluoroethane) and absorbent, DMF (dimethyl formamide). R134a vapour is injected into the absorber using two injectors of 4.8 mm inner diameter at an injection angle of 30° to the vertical axis and parallel to the azimuthal axis of the absorber which enhances mixing of R134a with liquid to increase the heat and mass transfer. Heat and mass transfer characteristic are presented in this paper in terms of operational parameters. Effect of solution pressure, solution flow rate, gas mass flow rate on heat and mass transfer rate, absorption rate, absorption efficiency, heat and mass transfer coefficients are computed numerical results.