Comparison analysis of mass diffusivity effect on a damper-controlled desiccant dehumidifier.

In order to apply the desiccant dehumidifier or the desiccant cooling system to the commercial or industrial use in a large capacity, the size of desiccant wheel is needed to be scaled up. However, these applications have difficulties in manufacturing and rotating the required large size of desiccant wheel due to the brittle nature of the desiccant material and the heavy weight of wheel. In the present study, a dampercontrolled desiccant dehumidifier with fixed desiccant modules is employed. In this desiccant dehumidifier,
instead of the desiccant material moving around between the sorption and desorption sides, the air streams for the sorption and desorption processes flow alternately by controlling the dampers while the desiccant module is fixed in position. The dehumidifier may be comprised of multiple pairs of desiccant modules so that the sorption and desorption processes operate consecutively. A prototype of the damper-controlled desiccant dehumidifier consisting of two desiccant modules has been built in a small scale. The dehumidification performance has been tested in various operation conditions including damper periods. Mass diffusivity as a
dehumidification performance index is proposed for a damper controlled desiccant dehumidifier. Performance comparison has been also made with numerical simulation results to verify mass diffusivity as an index for the dehumidification performance.