Energetic and Exergetic Analysis of a Solar-Driven Single-Effect Absorption Refrigeration System Using LiBr + LiCl/H2O Solution Mixture

Abstract

Comprising an eco-friendly blueprint, absorption refrigeration systems have attracted a lot of interest as they can use biomass, solar and geothermal energy sources which can mitigate climate change. The current study presents a methodology based on energy and analysis for solar-driven single-effect absorption refrigeration systems, which offer a 50-kW cooling capacity. This study proposes a new mixture ratio of LiBr + LiCl (mass ratio of 2:1)/H2O solution and compared it to LiBr/H2O thermodynamically. Based on the climate data of Kocaeli province in Turkey, an evacuated tube collector is employed to benefit from solar energy to meet the generator heat load of the system. Although at an evaporator temperature of 5 °C, enhanced thermodynamic performance is evident with the use of the LiBr + LiCl/H2O system, and a diminished solar collector area is required compared to the system utilizing LiBr/H2O; there is a level of attrition relating to the impact of the former with a single degree rise in evaporator temperature. However, this remained at a greater value than for the latter system. The final results pointed out that LiBr + LiCl/H2O has a 48.93% lower circulation ratio, 8.81% higher coefficient of performance (COP) of chiller, 8.88% higher solar COP, 8.96% higher exergy efficiency of chiller, 8.90% higher exergy efficiency of solar-driven system, 8.92% lower solar collector area, and 8.91% lower storage tank volume than LiBr/H2O system in the investigated operating temperature ranges. The final results of the present study can be safely tested in the experimental design of single-effect absorption chillers.