Entropy generation minimization of an advanced two-bed adsorption refrigeration system

This article presents the thermodynamic assessment of an advanced adsorption chiller with an aim towards entropy generation minimization through the selection of appropriate operating strategies, temperatures, and design modifications. The present study carries out a second law analysis of a two-bed silica gel water pair-based adsorption cooling system, with a focus on the under-explored aspects of a heat recovery strategy and auxiliary consumption-reducing measures. A second law performance index, viz. specific irreversibility, is introduced for effectively incorporating the entropy generation, auxiliary electricity consumption, and cooling capacity, and it has been further verified to be an indicator of second law efficiency. The performance of the system has been numerically evaluated under the normal and passive heat recovery strategies, where it is found that the passive heat recovery strategy offers a lower entropy generation by 63%. The study further investigates the second law efficiency impact of adopting a capillary-assisted evaporator for auxiliary electricity consumption reduction. It is observed that the specific irreversibility could reduce by up to 22% over a conventional falling film design. The analysis and results presented in this study are anticipated to increase the effectiveness of adsorption chillers for heat recovery applications. •Entropy generation analysis of a 10 kW adsorption chiller with passive heat recovery•Specific irreversibility is presented for optimum operating point determination•A hot water temperature of 65 °C is optimal for an effective waste heat utilization•Up to 63% reduction is noted on employing passive heat recovery strategy•Specific irreversibility could reduce by 22% with capillary assisted evaporator