OT-88-19-2 -- Liquid Desiccant Hybrids Complexity Made Simple PDF

Liquid desiccant hybrid systems, particularly those that have evolved in pioneering installations, are often perceived to be quite complex. This paper simplifies the processes involved, makes comparisons with better understood absorption chillers, and develops a representative thermodynamic COP for a simple desiccant system. The unique features of the liquid desiccant system can be exploited to make a cost-effective hybrid system, even though the COP of a basic desiccant system by itself is no better than that for a single-effect absorption chiller. The dominant features are shown to be: (I) the ability to accomplish the latent cooling at relatively warm temperatures(rather than at low dew point followed by reheat) and (2) the ability to use a regeneration temperature ty pical of waste heat or solar sources. These features promote integration with other HVAC systems, such as single-or double-effect absorption chillers, engine-driven chillers, c onventional electric driven chillers and indirect and/or direct evaporative cooling. Once the benefits of the hybrid systems are understood the perceived complexity is reduced.