Experimental investigation on performance of ammonia absorption refrigeration system with TiO2 nanofluid

This paper experimentally investigated the influence of the different amounts of TiO2 nanoparticles on the coefficient of performance (COP) of the ammonia-water absorption refrigeration system (AARS). Based on our previous experimental results and other researchers' literature, TiO2 nanofluids in mass fractions of 0.1%, 0.3%, and 0.5% were prepared and added to the newly built miniaturized AARS, also, the mixture of 0.5 wt% TiO2 and the 0.02 wt% SDBS was also applied. In the test conditions, evaporation temperatures ranged from -18 degrees C to 0 degrees C, generation temperatures ranged from 105 degrees C to 150 degrees C, and inlet cooling water temperatures ranged from 22 degrees C to 33 degrees C. Experimental results show that: the TiO2 nanoparticles have great effects on AARS, and the COP can be increased by up to 27%; the mixture of 0.5 wt% TiO2 and the 0.02 wt% SDBS has the most significant effect on the improvement of the COP compared to other nanofluid; the improvement of COP is strongly corresponded to the numbers of nanoparticles stably dispersed in the base fluid, not just the nanoparticles added; this paper provides evidences for the application of nanoparticles on AARS. (C) 2018 Elsevier Ltd and IIR. All rights reserved.