Air Dehumidification System Research Articles

The technical challenges for solid desiccant cooling

Air conditioning and dehumidification systems using solid desiccants have been developed and are finding niche applications in commercial building with special humidity problems or requirements. Ongoing research is being directed at materials and components investigations which have the promise of increasing the performance and reducing the cost of air conditioning systems to the point that they will realize broader application for building environmental control. This technical progress, coupled with intensive societal pressures for limiting the growth of peak electrical demand and release of global warming and ozone destruction gases, suggests that desiccant technology will experience an expanding penetration of the building air conditioning market.

Performance studies for an experimental solar open-cycle liquid desiccant air dehumidification system

A nominal 10.5-kW (3-ton) open-cycle liquid desiccant dehumidification system has been designed, installed, and successfully operated at the Solar Energy Applications Laboratory, Colorado State University. Packed bed units were used to dry the air in the dehumidifier and to concentrate the desiccant in the regenerator. Liquid distribution in the regenerator was studied for two systems: a gravity tray distributor, and a spray nozzle system. Higher capacities (40–50% increase) and lower pressure drop (30–40% reduction) for the air flow were observed with the spray system. Cooling capacities of 3.5–14.0 kW (1.0–4.0 refrigeration tons) were achieved for both the regenerator and dehumidifier. Functional relationships correlating the independent variables to the rate of vaporization in the regenerator and rate of condensation in the dehumidifier were obtained by statistical analysis of the experimental data. These studies thus provide data and correlations useful for design guidance and performance analysis of similar open-cycle liquid desiccant cooling systems, particularly for the liquid/vapor contact units.