An energy efficient solar-assisted advanced adsorption chiller system

Abstract

The rise in living standards and the environmental challenges associated with fossil energy has attracted engineers and researchers to focus on energy use of buildings. Buildings consume 40% of world’s total energy consumption and air-conditioning alone consumes 15% of building’s total energy consumption. The integration of solar energy with adsorption cooling technology is an attractive area of research. The thesis develops a literature review of adsorption working pairs and different nanofluids used as cooling liquid in the adsorption chiller system. An advanced adsorption chiller system uses composites ‘salt inside porous matrix’ (CSPM) as adsorption material and multiwalled carbon nanotubes/graphene nanofluid (MWCNT/GNF) as cooling liquid. An adsorption chiller model used in TRNSYS simulation software compares temperature profiles of different components like solar collector, hot storage tank and an office space for conventional silica gel↔water and activated carbon fiber with barium chloride salt (ACF/BCS)↔ammonia adsorption chillers. The effect of MWCNT/GNF to improve performance of adsorption chiller is analysed. It is found that activated carbon fiber/nickel chloride salt (ACF/NCS) and ACF/BCS can improve the coefficient of performance (COP) by 23.4% and 95.7%, respectively. The later part of the thesis develops a nonlinear model predictive control (NMPC) model for (ACF/BCS)↔ammonia adsorption chiller system. The cumulative fossil fuel consumption for an year reduces by 61.3% using the NMPC approach for (ACF/BCS)↔ammonia adsorption chiller plant. The potential benefits of the application of NMPC in optimal management of solar energy, improving energy-efficiency and thermal comfort for an office space are highlighted in this study.