Thermal contribution-driven energy matching for internal heating regeneration in microchannel-corrugated fin regenerators under extreme hot-humid climate

Under extreme hot-humid climatic conditions, the regeneration efficiency of liquid desiccant air conditioning systems significantly decreases due to insufficient vapor pressure difference. Although internal heating regeneration has emerged as a promising solution, comprehensive understanding of its thermal contribution mechanism and energy matching principle remains limited. This study developed a microchannel-corrugated fin internal heating regenerator (MF-IHR) and systematically investigated its regeneration performance from the perspective of thermal contribution. Experimental results demonstrate that the MF-IHR enhances the solution moisture removal rate by up to 72.0% compared to adiabatic operation. Thermal contribution analysis reveals that as the temperature of hot water rises, the heating power ratio of water (HPRW) increases from 33.3% to 87.5%, the heat loss power ratio of solution (HLPRS) decreases from 66.7% to 12.5%, and the regeneration efficiency drops from 58.8% to 26.4%. Under extreme environmental conditions, air humidity dominates thermal contribution distribution, with HPRW increasing from 62.1% to 87.2% as humidity rises from 18.3 g/kg to 26.7 g/kg. These findings demonstrate that balancing thermal contributions, rather than maximizing heat input, is key to optimizing regeneration performance. This study provides valuable insights for achieving efficient liquid desiccant regeneration in extreme hot-humid climates.