Performance prediction of a two-bed solar-powered adsorption chiller with heat and mass recovery cycles and adaptive cycle time – A first step towards the design of fully autonomous commercial-scale adsorption chillers

• Published in: Applied thermal engineering Vol. 192; p. 116950
• Main Authors: Qadir, N.U., Xu, Z.Y., Pan, Q.W., Said, S.A.M., Mansour, R.B., Akhtar, K.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 25.06.2021; Elsevier BV
• Subjects: Adsorption; Chillers; Cycle time; Desorption; Efficacy; Heat recovery; Heat recovery systems; Heat/mass recovery; Mathematical analysis; Performance prediction; Radiant flux density; Simultaneous; Solar energy; Solar radiation; Efficacy; Desorption; Adsorption; Simultaneous; Heat/mass recovery
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2021.116950

•A two-bed solar-powered adsorption chiller with heat and mass recovery is proposed.•The adsorption/desorption, heat and mass recovery times are all adaptive in nature.•Previous studies propose no logic for precedence of mass recovery over heat recovery.•This study proposes a logical explanation of the more commercially viable sequence.•The proposed chiller can operate in fully autonomous mode with no human intervention. The previously published literature based on the performance prediction of solar-powered adsorption chillers generally incorporates fixed heat/mass recovery (HR/MR) cycle times which remain unchanged during the entire course of operation of the adsorption chiller. In reality, the dynamics of the HR/MR processes are continuously subject to change due to temporal variations in the solar radiation intensity, and thus fixed HR/MR cycle times might not prove to be compatible with the actual dynamics of a transient solar-powered chiller operation. The current study proposes a numerical scheme for performance modeling of a commercial-scale adsorption chiller with adaptive HR/MR cycle times following the adsorption/desorption (ads/des) cycle. A novel model of the MR cycle has been proposed which, in accordance with the best knowledge of the authors, cannot be find anywhere else in the previously published literature. The ads/des→HR→MR→des/ads half cycle has been predicted to yield an almost 52% higher cycle-averaged value of coefficient of performance (COP), an almost 16% higher value of specific cooling power (SCP), and a roughly 146% higher value of solarCOP (COPsc) than the ads/des→MR→HR→des/ads half cycle over the entire course of operation of the adsorption chiller till sunset.