The impact of wettability on the performance of a two row wavy fin and tube liquid desiccant system for dehumidification and regeneration

Abstract

This study investigates the challenge of enhancing wettability in falling film type dehumidifiers/regenerators, a crucial factor in optimizing the performance of building air conditioning systems. The emergence of Severe Acute Respiratory Syndrome (SARS) has underscored the need for improved indoor air quality (IAQ) and energy efficiency. This research specifically addresses the suboptimal wettability issue in fin and tube liquid desiccant systems, which is essential for efficient dehumidification and regeneration processes. The experimental setup employed a cross-flow configuration within the heat exchanger elements, where the flow of ionic liquid intersected with horizontal airflow through cooling and heating coils. By systematically adjusting the wettability on the heat exchanger surfaces, the study examined its impact on relative humidity and dry bulb temperature at the system's inlet and outlet. The results indicate that the wetting fraction on fin and tube surfaces significantly influences the delta humidity ratio of air. In the dehumidification phase, for instance, the delta air humidity ratios varied between 9.4 and 9.7 g/kg with corresponding wetting ratio values ranging from 0.47 to 0.5. Similarly, during regeneration, delta air humidity ratios fluctuated from 9.08 g/kg to 9.6 g/kg, with wetting fractions between 0.47 and 0.5. In conclusion, this study offers in-depth insights into the impact of wettability on the efficiency of fin and tube liquid desiccant systems. These findings have implications for enhancing IAQ and energy efficiency in building air conditioning, particularly in tropical regions like Indonesia.