Experimental parameter study and correlation development of microchannel membrane-based absorption process for efficient thermal cooling with high compactness

• Published in: Energy (Oxford) Vol. 279; p. 128080
• Main Authors: Zhai, Chong, Wu, Wei
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.09.2023
• Subjects: Correlation development; Heat and mass transfer; Microchannel membrane-based absorber; Prediction accuracy; Solution pressure drop; Prediction accuracy; Solution pressure drop; Microchannel membrane-based absorber; Heat and mass transfer; Correlation development
• ISSN: 0360-5442
• DOI: 10.1016/j.energy.2023.128080

The microchannel membrane-based absorber occupies a crucial position in an efficient and compact absorption refrigeration system, as it directly influences the system's cooling capacity. However, existing numerical models for describing the absorption process of this absorber often exhibit large deviations, as they are adopted from other processes. To establish highly accurate correlations, extensive experiments are performed in this study to evaluate the absorption process using H2O/LiBr as the working fluids across a wide range of operating conditions. The experimental results demonstrate that enlarging the solution flow rate, vapor pressure, and solution concentration or lowering the cooling water temperature can improve the heat and mass transfer processes significantly. By analyzing the experimental results, new correlations of Nusselt number (Nu), Sherwood number (Sh), and friction factor (f) are developed for heat/mass transfer and solution pressure drop, respectively. It is verified that these newly developed correlations significantly enhance the prediction accuracy of the overall heat transfer coefficient (U), absorption rate (J), and pressure drop (DP) by 72.39%, 78.55%, and 64.56% when compared to existing literature correlations. The exceptional accuracy achieved by these correlations contributes significantly to the design, evaluation, and optimization of efficient and compact absorbers, enabling further advancements in this field. •Microchannel membrane-based absorber using H2O/LiBr is experimentally studied.•Raising vapor pressure benefits heat/mass transfer and lowers the pressure drop.•Reducing cooling water temperature improves Nu and Sh but increases f.•New correlations for Nu, Sh, and f are obtained with errors within 30%, 30% and 25%.•Prediction accuracies of Nu, Sh, and f are improved by 72.39%, 78.55% and 64.56%.