ENERGY AND EXERGY ANALYSIS OF USING FeOTiO2 NANOFLUID IN DIFFUSION ABSORPTION REFRIGERATION SYSTEMS

This study aims to improve the passive heat transfer in the diffusion absorption refrigeration (DAR) system by using suspension of FeOTiO2 nanoparticles in ammonia/water base-fluid as a new working solution. For this purpose, certain amounts of nanoparticles were added to the used base-fluid in 1 wt.% and 2 wt.% concentrations in two separate tests. No previous study has investigated ammonia/water working solution with this kind of hybrid nanosize particles. The nanofluids of the two concentrations were experimentally compared with only the base-fluid as a reference solution. Also, the calculations of properties of the required variables for energy and exergy analyses such as the enthalpy entropy required for thermodynamic calculations at the measurement points of the fluid in the cycle were performed depending on the fundamental properties such as the experimentally measured temperature and pressure. As a result, it has been determined that the input temperature to the generator-bubble pump component is the most effective factor in the system performance. The DAR system which was run by 1 wt.% nanofluid had better performance than 2 wt.% nanofluid. In the 1 wt.% nanofluid cycle the enhancement of COP, circulation ratio, and internal temperature reached 17%, 57%, and 20%, respectively, compared with the reference fluid cycle. Furthermore, as a result of the exergy analysis, the highest reduction of the total exergy losses was 4.5% in the system that is run by 1 wt.% nanofluid compared to the reference solution.