Experimental investigation on a desiccant dehumidification unit using fin-tube heat exchanger with silica gel coating

In this paper, an experimental setup of a desiccant dehumidification unit silica gel coated fin-tube heat exchanger is installed and investigated. In this unit, two silica gel coated heat exchangers (SCHE) are adopted and switched to provide continuous dehumidification capacity. Meanwhile, hot water from vacuum tube solar collector is used to regenerate silica gel. System performance is evaluated in terms of moisture removal mass and thermal COP. Influences of major parameters on system performance are tested and analyzed under Shanghai summer conditions. It is found that system performance is affected significantly by cycle time between dehumidification and regeneration, and optimal cycle time is 600 s under test conditions. For actual system, the unit can be independently used as dehumidifier with 100% fresh air under mild conditions. But when the outside humidity is too large, it can be used in combination with primary return air-conditioning to provide satisfied supply air.