Quantifying the effect of nanoparticles addition to a hybrid absorption/recompression refrigeration cycle

Space heating and cooling constitute a major share of electricity consumption in buildings. Nanoparticles provide a powerful solution to improving the efficiency of heating and cooling systems. The effects of nanoparticle addition on the efficiency improvement of a novel absorption-recompression refrigeration system is characterized in the present paper. Three different types of nanoparticles (Fe, Al2O3 and SiO2) are evaluated by varying volume fractions of dissolved nanoparticles in LiBr-H2O solution, flowing in specific parts of the proposed hybrid cycle. The effect of nanoparticle addition on heat exchange rate of absorber, plate heat exchanger and generator is quantified. The pressure drop of heat exchanger, compressor power consumption and overall energetic and exergetic effects are compared and assessed at volume fractions ranging from 0 to 5%. A theoretical analysis indicates market improvement in the coefficient of performance, exergy efficiency and heat exchange properties at the component level in the presence of nanoparticles. The results show the quantitative levels of improved performance and differences among options: addition of Fe nanoparticles is most effective when compared to Al2O3 and SiO2. Adding of Fe nanoparticles (5% by vol) led to the maximum improvement of 7.6% in the effectiveness of heat exchanger, a maximum reduction of 11.8% in compressor power consumption, and a maximum improvement of 14.6% in coefficient of performance. (C) 2020 Elsevier Ltd. All rights reserved.