Performance analysis of a hybrid air-conditioning system dehumidified by liquid desiccant with low temperature and low concentration

For temperature and humidity independent control (THIC) air-conditioning systems that integrated liquid desiccant dehumidification technology, it is very good idea to use condensation heat of the vapor compression system for the liquid desiccant regeneration. However, the system is unable to work in situations of humid climate or high latent load, since the condensation heat may not satisfy the regeneration of the liquid desiccant. This paper proposed a novel THIC air-conditioning system based on liquid desiccant, in which liquid desiccant with low-concentration and low-temperature was used in air dehumidification, and the condensation heat could meet the need of the regeneration of desiccant solution. A validated mathematical model was used to investigate the performance of the novel system under different operation conditions. The results showed that under typical indoor condition in Nanjing summer, mass concentration range of 25.4-26.9% was suggested in the dehumidification process using LiCl-H2O, and the dehumidification temperature range of the desiccant was around 17-19 °C. The effects of the ratios of indoor sensible load to latent load, and the outdoor air temperature and humidity on the system performance were discussed. Performance comparisons showed that COPsys of the system was 13.6-116.1% more than that of the conventional system under different operation conditions.