An Experimental Study Onthe Dehumidification Performance of a Low-flow Falling-film Liquid Desiccant Air-conditioner

AbstractThe dehumidifier is one of the main componentsinopen-cycle liquid desiccant air-conditioning systems. An experimental study was carried out to evaluate the performance of asolar thermally driven, low-flow, falling-film, internally-cooledparallel-plate liquid desiccant air-conditioner in Kingston, Ontario at Queen's University. A solution of LiCl and water was used as the desiccant.Unlike high-flow devices, the low-flow of desiccant solution flowing across the unit's dehumidifier and regenerator sections produces large variations in solution concentration. In this study, a series of tests were undertaken to evaluate the performance of the dehumidifier section of the unit. Results presented are based on mass flow and energy transport measurements that allowed the moisture transport rate between the air and liquid desiccant solution to be determined. Based on these results, arelationship between the desiccant concentration and the rate of dehumidification rate was found and the effect of inlet-air humidity onthe dehumidification effectiveness identified. The moisture removal rate of the system was found to range from 1.1g/s to 3.5g/s under the conditions evaluated. These result corresponded to an average dehumidification effectivenessof 0.55