Review on the fundamentals and investigations of falling film dehumidification/absorption refrigeration based on CFD technology

Abstract

The falling film type liquid desiccant dehumidification cooling system and absorption refrigeration system are regarded as promising technologies due to their energy saving potential and utilization of low-grade energy. CFD (Computational Fluid Dynamics) technology has been continuously developed due to its advantages in analyzing the elaborate flow, heat and mass transfer behavior in thermodynamic processes. The present review comprehensively summarized previous studies concerning the simultaneous fluid flow, heat and mass transfer in falling film liquid desiccant dehumidification and absorption refrigeration system. Firstly, the mathematical governing equations for the description of flow and absorption process were described. Interphase-capturing methods including volume-of-fraction model, level-set model and front tracking model were introduced then. Subsequently, different types of mass transfer model for the calculation of interface mass flux were summarized. Finally, the related CFD studies on the falling film liquid desiccant dehumidification and absorption refrigeration process were reviewed in detail. Conclusions and some suggestions for future work were presented as well. The present review is expected to provide a helpful reference for the further study of the coupled hydrodynamic, heat and mass transfer characteristics in falling film heat and mass transfer components.