A dual-scale analysis of a desiccant wheel with a novel organic–inorganic hybrid adsorbent for energy recovery. (1st February 2016)

• Record Type: Journal Article
• Authors: Fu, Huang-Xi; Zhang, Li-Zhi; Xu, Jian-Chang; Cai, Rong-Rong
• Is Part Of: Applied energy. Volume 163(2016)
• Page Start: 167
• Page End: 179
• Publication Date: 2016-02-01
• Subjects: Multi-scale modeling -- Desiccant wheel -- Energy recovery -- Molecular dynamics simulation -- Hybrid adsorbent; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2015.10.175
• Languages: English
• ISSNs: 0306-2619

Abstract

Graphical abstract: The dual-scale modeling of desiccant wheels. Highlights: A dual-scale modeling approach was proposed for a desiccant wheel. It includes a micro-scale molecular dynamics (MD) sub-model for adsorbent material. It also includes a macro-scale sub-model for heat and mass transfer in matrix channels. The system can be designed from perspectives of "material-performance-system". Abstract: Desiccant wheels have been extensively used for energy recovery of ventilation air from buildings. Performance of these wheels is influenced by many factors like the material properties, wheel matrix structures, operating conditions and fluid parameters. Previous studies only involved the macro-scale heat and mass transfer in the wheels and the system performance, by neglecting the micro-scale properties of wheel materials. In this study, a dual-scale modeling approach was proposed for a desiccant wheel with a novel organic–inorganic hybrid adsorbent (HA) material which combines high adsorption capability with good mechanical durability. The proposed dual-scale model included a micro-scale molecular dynamics (MD) sub-model for adsorbent material, a macro-scale sub-model for heat and mass transfer in matrix channels and system performance evaluation. The two sub-models were linked together through information exchange to form the dual-scale model. Through modeling, the effects of the micro physical–chemical properties of materials and macro structure of wheels, as well as the operating parameters on system performance were investigated. With the dual-scale model as a design tool, material compositions were optimized. The moisture adsorption capacity of the material was two times higher than that of silica gel B at high relative humidities. Consequently the sensible and latent effectiveness were improved by 12% and 30% respectively.