Air-conditioning and fresh water are increasingly required in civilian and industrial sectors; however, conventional technologies are generally individual systems and consume substantial electric power. This paper proposes a new solar-powered double-product system for cooling and water based on the absorption refrigeration cycle. Integrated with liquid desiccant dehumidification, the moisture of process air can be converted into fresh water without the use of an additional desalination unit. Adopting commercially established technologies, including absorption refrigerators and liquid desiccant dehumidifiers, the system exhibits enhanced energy and economic performance. With the same system output, the energy saving ratio in the proposed system could reach 25.64%. The exergy efficiency (ηex) for the proposed system reaches 9.83%, which is 2.97% higher than that in the reference systems. Economic studies show the enhanced economic performance of the new poly-generation system. This study provides a new method to simultaneously produce cooling and water by efficiently using solar energy.
Conclusions:
Aiming at reducing the energy consumption of conventional individual systems and improving the economic performance, a new solar-powered absorption refrigeration system integrated with liquid desiccant dehumidification was proposed, which simultaneously realizes air-conditioning and fresh water production. The proposed system can be used as a stand-alone unit to meet a high cooling load and as a small- or middle-scale device for fresh water production with some commercially established technologies, including absorption refrigerators and liquid desiccant dehumidifiers. The proposed system is suitable for application in warm-climate and water-deficient regions where solar energy is rich or in various industrial sectors in which substantial waste heat exists. The energy, exergy and economic analysis was conducted to validate the technical feasibility of this new doubleoutput system.
(1) On the base-case condition, with the same outputs of air-conditioning and fresh water, ESR and ESRsol can reach 25.64% and 24.42%, respectively. GORsol in the proposed system can reach 0.81, and it is 35% higher than that in reference individual systems.
(2) The exergy efficiency (ηex) for the proposed system reaches 9.83%, which is 2.97% higher than that in the reference systems. With the same exergy outputs in both the proposed and reference systems, the exergy destruction in the proposed system decreases significantly because of the reduced solar collection temperature and input solar energy.
(3) Economic studies have shown that the novel double-output system exhibits enhanced economic performance with a reduced total equipment investment of $30,884 (42.9%). The new integrated system for both refrigeration and water production with solar energy remains one of the most favorable choices in isolated and remote areas. This study provides a new method to simultaneously realize airconditioning and fresh water production by efficiently using solar energy with various mature technologies.
The results have been published on Energy Conversion and Management 153 (2017) 515–525.
Fig. 1 Flow chart of the solar-powered absorption refrigeration system combined
with liquid desiccant dehumidification.
