Performance comparison on different liquid desiccants in the liquid desiccant air-conditioning using electrodialysis regeneration: LiCl and LiBr aqueous solutions

As different liquid desiccants show different dehumidification and operation characteristics, the comprehensive performance comparison between two liquid desiccants (LiCl and LiBr aqueous solutions) was conducted in this paper. The electronic conductivity of the LiBr aqueous solution was experimentally investigated and the electronic conductivity model of the LiBr solution was acquired. Compared with the LiCl solution, the LiBr solution has higher electronic conductivity within the concentration range of 20–40% and the temperature range of 20–60 °C, which means the ED regenerator using LiBr solution has lower electric resistance. The increase of the liquid desiccant concentration is beneficial to the moisture removal rate but harmful to the whole system COP and dehumidification efficiency, while the effect of the liquid desiccant temperature is opposite. Within the liquid desiccant temperature range of 20–30 °C, the whole system COP varies among 1 and 2.8 for the LiCl solution with the concentration of 38% at the exit of the ED regenerator, and it is among 2.5 and 5.8 for the LiBr solution with the concentration of 55% after regeneration. Using the LiCl solution can give the system the better dehumidification potential, while using LiBr solution can help the system to acquire the better whole performance and economy.