Theoretical investigation of a novel unitary solid desiccant air conditioner

Abstract

To achieve higher energy efficiency and higher moisture removal capacity, a novel unitary solid desiccant air conditioner was proposed for hot and humid climate based on a novel concept of water-sorbing heat exchanger. The so-called water-sorbing heat exchanger is made by coating desiccants onto the coils used in traditional unitary air conditioners. As such, sensible load will be handled by convective heat transfer without overcooling and latent load will be treated by desiccants regenerated by heat of condensation. The air leaving the evaporator rightly satisfies the required supply-air. Evaporation temperature will increase and reheating is no longer needed. Condensation temperature will effectively decrease due to the enhancement of airside heat dissipation, which results from adsorbed water evaporating. One simple thermodynamic model was developed with some essential assumptions and the feasibility was theoretically analyzed. Parametric studies were conducted and power saving potentials of unitary solid desiccant air conditioner were investigated. The results showed that the unitary solid desiccant air conditioner could achieve more than twice as much energy efficiency over the current baseline technologies.

Funding

The authors acknowledge the financial support of the project supported by the State Key Program of National Natural Science of China (Grant No. 51336004) and the project supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant No. 51521004).