Energy and exergy analysis of a double effect LiBr-H₂O and LiCl-H₂O chillers

Abstract

Absorption refrigeration systems (ARS) is a type of environmental friendly technology with zero ozone depletion and global warming potential that can utilize industrial waste heat and renewable energy sources such as solar and geothermal. Therefore, there is an ongoing effort and many research for further improvements. A comparative study between single effect and double effect absorption refrigeration systems using lithium bromide/water and lithium chloride/water as working fluid solutions is presented in this paper. The coefficient of performance (COP) and the second law efficiency (exergetic efficiency) of absorption system under different operating conditions are calculated. Simulation results are used to evaluate the influence of the various operating parameters on the performance coefficient, the thermal loads of the system components, exergetic efficiency and the total change in exergy of the systems. It is observed that operation temperatures of the overall system and its components have a major effect on their performance and functionality. In this regard, a parametric study conducted here to investigate this effect on heat capacity and exergy destruction of the system components. Also, a comparative analysis for the working fluids is carried out. It is observed that the COP of double effect system is considerably higher than the COP of single effect system, however, the exergetic efficiency of double effect system is slightly higher than the exergetic efficiency of single effect system.