Modeling and performance analyses of a batch-wise liquid desiccant air conditioning system

Abstract

Numerous efforts have been made and reported to improve the energy efficiency of liquid desiccant air conditioning (LDAC) in recent studies. This study proposes a novel batch-wise operation strategy for LDAC that desiccant solutions in dehumidifier and regenerator are circulating independently and exchanging intermittently to get a full utilization of solution dehumidification capacity, cooling and heating energy. System models, including heat and mass transfer models of dehumidifier and regenerator, heat exchanger models and solution transfer model, are developed and verified to analyze and estimate the performance of proposed batch-wise strategy. The maximum relative errors between experimental and model predicting results are within 9.69% for outlet air temperature and within 7.97% for outlet air relative humidity. Performance and energy efficiency of proposed strategy are analyzed and compared with normal on-going solution exchange strategy. According to the simulation results, dehumidification rate and regeneration rate can be improved by average of 5.00% and 3.50% due to multiple solution usages in dehumidifier and regenerator. Moreover, the proposed batch-wise strategy demonstrates considerable energy savings with up to 16.81% and 18.60% from dehumidifier and regenerator, respectively.