Performance enhancement in LiCl-H2O and LiBr-H2O absorption cooling systems through an advanced exergy analysis

This research study compares the thermodynamic performance of 10kW lithium chloride-water (LiCl-H2O) and lithium bromide-water (LiBr-H2O) absorption cooling systems through first and second law of thermodynamics. Further, the exergy degradations happening in each component have been split into unavoidable and avoidable exergy degradations as well as endogenous and exogenous exergy degradations through advanced exergy analysis. Pressure-temperature-concentration (P-T-X) diagrams are drafted to clarify the real, ideal, and unavoidable cycles for LiCl-H2O and LiBr-H2O absorption cycles. Moreover, this paper exhibits the sensitivity of various system components towards the generator, condenser, and absorber temperature for both pairs. Energetic observation proves that LiCl-H2O pair is 10% more efficient as compared to LiBr-H2O pair. Exergetically, LiBr-H2O cycle struggles with additional (nearly 13.45%) exergy destruction than LiCl-H2O cycle. The major contribution (around 70% to 80%) of irreversibility comes from the generator and absorber. Comprehensively, the parametric partitions of irreversibility rate in each component provide broad indications to prioritize the system components for enhancements.