Exergetic-energetic effectiveness of a simple H2O-LiBr absorption chiller operated by solar energy collected using a direct flow evacuated tube collector

Abstract

A comprehensive examination of a 10-kW simple H2O/LiBr absorption system energized by an evacuated tube solar collector of the single-ended glass direct flow type has been conducted. For various operating conditions, the thermal and exergetic performance coefficients (COP, ECOP respectively), and exergy destruction (ΔE) through each system component are determined. At evaporator temperatures of 1°C, 5°C, and 10°C, COP around 0.75, 0.77, and 0.81, respectively, was achieved, and the maximum ECOP values of approximately 0.36, 0.35, and 0.342, respectively, could be attained. The highest values of COP and ECOP were seen at a desorber temperature of around 90°C. Around 41% of the system’s exergy destructed were attributed to the desorber. The lowest absorber exergy losses occur at a desorber temperature of 90°C for various evaporator temperatures. Increasing the desorber temperature by a factor of two reduces the system’s efficiency from 0.45 to 0.20. In addition, 65.88% solar collector exegetic efficiency was achieved when its differential temperature surpasses 50°C.