Experimental analysis of an internally-cooled liquid desiccant dehumidifier

The simultaneous cooling in the dehumidification of an internally-cooled process is quite different from an adiabatic process that uses liquid desiccant. In the present study, the operating performance of an internally-cooled process was examined through both experimental tests and simulation analysis. An internally-cooled dehumidifier made of stainless steel was designed, and experimental results in different working conditions were analyzed using a lithium bromide (LiBr) aqueous solution. The moisture removal rate, dehumidifying efficiency, and volume mass transfer coefficient were adopted as indices to evaluate the performance. The effects of the inlet parameters on these performance indices were investigated. The predicted results by the numerical model agreed well with the experimental results. The validated model was then utilized to predict the performance of the entire internally-cooled/heated air handling system, in which low regeneration temperature could be realized. An internally-cooled/heated system driven by the exhaust heat of heat pump was then proposed, and COP was in the range of 4.2–6.5.

► Experiments on an internally-cooled dehumidifier are carried out using LiBr.
► Effects of tw,in, m˙wandm˙s on the dehumidifying performance are investigated.
► Theoretical model for an internal cooled/heated system is built and validated.
► An internally-cooled/heated system driven by the heat pump is analyzed.