The Optimized Operation of a Solar Hybrid Desiccant/Displacement Ventilation Combined with a Personalized Evaporative Cooler

Abstract

The study investigates by modeling and experimentation the performance of displacement ventilation (DV) aided with personalized evaporative cooler (PEC) system that operates in humid climate and uses a solid desiccant (SD) dehumidification system regenerated by parabolic solar concentrator thermal source. Predictive component models of the conditioned space, the SD, the solar concentrator system, and the PEC were developed and used for the prediction of associated operational energy consumption while utilizing an optimized control strategy. The control strategy seeks optimal values of supply air flow rate and temperature and the desiccant regeneration temperature for both cases with and without the aid of the PEC while meeting space load, indoor air quality, and thermal comfort requirements. Energy consumption was calculated for the optimized strategy using genetic algorithm optimizer and the integrated DV/SD-PEC models. The results agreed well with experimental data obtained from tests on a DV climatic chamber. In addition, votes of comfort recorded by participants in the experiment using PEC were very similar to predicted comfort. The optimized hybrid system performance was applied to a typical office space of area of 64 m². The operation of the hybrid system with PECs resulted in a higher supply air temperature. The increment in supply air temperature is 1.1°C when PEC is used compared to case without PEC. This increase in temperature showed that an energy saving of 13.5% is achieved for the PEC aided hybrid system.

Keywords:

• Desiccant dehumidification
• Hybrid air conditioning systems performance
• Optimized air conditioning control strategy
• Displacement ventilation
• Personalized evaporative cooler