On the application of adsorber plate heat exchangers in thermally driven chillers; An experimental and analytical study. (5th February 2023)

• Record Type: Journal Article
• Authors: Mikhaeil, Makram; Gaderer, Matthias; Dawoud, Belal
• Is Part Of: Applied thermal engineering. Volume 220(2022)
• Publication Date: 2023-02-05
• Subjects: Siogel -- Adsorber plate heat exchanger -- Adsorption and desorption kinetics -- Heat transfer characteristic length -- Mass transfer characteristic length -- Specific cooling power; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2022.119713
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: Kinetic study on the adsorbent domain dimensions of adsorber plate heat exchangers. Analytical model to estimate the performance indicators of an adsorption chiller. Adsorption kinetics mainly influenced by the mass transfer characteristic length. Desorption kinetics dominated by the heat transfer characteristic length. Newly introduced adsorber plate heat exchanger demonstrates promising performance. Abstract: The effect of both heat and mass transfer characteristic lengths (HTCL, MTCL) of two different adsorber plate heat exchangers (APHE), for application in an adsorption chiller, on the adsorption and desorption kinetics is investigated. Three representative test frames (TF1-TF3) are prepared to examine small-scale adsorbent samples of the microporous silica gel (Siogel of Oker-Chemie, Germany) applying the volumetric large-temperature-jump methodology at different operating conditions. Based on the obtained kinetic data, an analytical model has been developed to predict the specific cooling power ( SCP ) and the coefficient of performance ( COP ) of a single-bed adsorption chiller comprising the studied APHEs. It turned out that, within the tested range of HTCL and MTCL, it can be concluded that, the adsorption kinetics are mainly influenced by the MTCL, while the desorption kinetics are dominated by the HTCL of the adsorbent domain. Applying Siogel as loose pellets inside a newly introduced APHE results in SCPs of 423.3 and 182.7 W⋅kg −1, at the evaporator temperatures of 15 °C and 5 °C, respectively. Herein, the condenser and adsorber-end temperatures amount to 30 °C and the desorption-end temperature to 90 °C. The corresponding COP s amount to 0.50 and 0.40, respectively, which represent quite promising results for further design optimizations.