Performance study of the internally-cooled ultrasonic atomization liquid desiccant dehumidification system

Abstract

Liquid desiccant dehumidification system (LDAC) has drawn much attention in recent years for its great energy-saving benefits in the HVAC industry. However, its performance is severely constrained by the considerable heat released within the dehumidifiers. One solution for this is adding the internal-cooling, but the necessary cooling temperature has remained low due to the dehumidifiers’ limited heat and mass transfer performance. To this end, a novel internally-cooled ultrasonic atomization dehumidification system (IC-UADS) was studied in this work. A model based on the conversion laws of mass and energy, and the sensible heat balance, was developed for performance prediction. Thorough experiments were conducted under various conditions of the airstream, the desiccant solution, and the cooling water to validate the model and good consistency was achieved. The results indicate that dehumidification performance was remarkably improved by 64.9% in the IC-UADS comparing to the adiabatic one. Besides, lower-grade cooling source can be well utilized in the IC-UADS with available cooling-temperature over 25.6 °C, which could even be from the tap water. Moreover, compared to the packed-bed systems, the IC-UADS presented better effectiveness that increased from 47.4% to 80.1%. This study may help enhance the performance and extend the applicability of internally-cooled LDACs.