NY-91-08-3 -- A Liquid Desiccant Dehumidifier Performance Model PDF

The application of liquid desiccants to conventional space conditioning has received a substantial amount of attention in recent years. The state-of-the-art residential liquid desiccant dehumidifier uses a parallel-plate cross-flow conditioner heat exchanger where latent load is removed from the indoor air and the heat of absorption is rejected to an outdoor airstream through evaporative cooling. A numerical model was developed to evaluate an improved counterflow conditioner design, which may offer significant performance and cost advantages. The analysis demonstrated that the conditioner's performance depends on only two dimensionless parameters, the Reynolds number and the L/D (plate length over spacing) ratio. Effectiveness, capacity, and operating cost maps were created, which constitute sufficient criteria for a counterflow design. The analysis, development, and results of the model are discussed.

KEYWORDS: dehumidifiers, absorbtion dehumidifiers, desiccants, performance, calculating, space cooling, cross flow heat exchangers, evaporative cooling, Reynolds numbers.