IIR document

Carryover free two-stage regenerator based liquid desiccant dehumidification system.


A desiccant dehumidification system (DDS) uses low-grade thermal energy, reduces latent cooling load and improves indoor air quality. The paper presents the results of experiments performed on prototype calcium chloride liquid desiccant based DDS using a carryover free two-stage regenerator and dehumidifier, which use the novel contacting device developed at the Heat Pump Laboratory, Bombay. The contacting device based on a proprietary, patent pending design, operating with low air velocities, in the range of 1 to 2.4 m/s, ensures that there is no salt carryover from the dehumidifier and regenerator. It neither has solution spray nor a packed column. High surface densities in the range of 465 to 600 m2/m3 make this system 1/2 to 1/3 the size of conventional packed systems. Wetting of the contacting media is ensured even at very low liquid throughputs. The air side pressure drops in the contacting devices are as low as 50 to 100 Pa, hence reducing the blower power. The two-stage regenerator used in the DDS requires 30 to 40% less energy to vaporise water as compared with that in a single-stage regeneration process. Experimental results show that the DDS using two-stage regenerator removes 2.5 kg of moisture per kWh of heat input. This will lead to over 60% reduction in primary energy consumption as compared to vapour compression system used for moisture removal. Thus reducing the CO2 release and favourably addressing global warming issues.

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  • Original title: Carryover free two-stage regenerator based liquid desiccant dehumidification system.
  • Record ID : 2004-2942
  • Languages: English
  • Source: 21st IIR International Congress of Refrigeration: Serving the Needs of Mankind.
  • Publication date: 2003/08/17


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