Performance Analysis of Square Port Microchannel Condenser using various Nanofluids in Refrigeration System

Abstract

Air-conditioning and refrigeration applications are critical in the domestic, commercial and industrial systems, which include food preservation, medical storage and thermal control of electronic systems. There is a need to make these systems more energy efficient to minimise the use of electricity and increase environmental sustainability. Effective heat transfer in the condenser and evaporator is important in the performance of a vapour compression refrigeration (VCR) system. In recent times, the use of microchannel heat exchangers and nano-refrigerators has become a viable strategy to improve the performance of the heat transfer. This is experimental research as it involves the determination of the impact of nanoparticles on the performance of the VCR system using TiO₂ and Al₂O₃ nanoparticles at 2 g and 3 g concentrations, respectively, with a constant refrigerant flow rate of 10 LPH. Performance measurement was done on the cooling capacity (Q₀), compressor work (Wc), and coefficient of performance (COP). It was experimentally found that nanoparticles led to a significant increase in the thermodynamic efficiency of the refrigeration system relative to that of the base refrigerant. The cooling effect was directly proportional to the concentration of nanoparticles, and the maximum cooling effect was realised at 3 g TiO₂ nano-refrigerant. On the same note, the cop values of all nano refrigerant cases recorded higher values compared to the pure refrigerant, with the highest average cop values recorded with 3 g TiO₂ and then 3 g Al₂O₃. The COP was improved primarily because of the rise in the refrigeration effect, and not because a significant decrease in compressor work was achieved. Moreover, the nanoparticle concentration between 2 g and 3 g had a positive effect on the performance of the system, which validates the importance of nanoparticle concentration in enhancing the performance of the heat transfer system. In general, the findings show that nano-refrigerants and especially TiO₂ nano-refrigerants can remarkably improve the efficiency of the vapour compression refrigeration systems without necessarily impacting negatively on the system’s operation. These results demonstrate the promise of nano-refrigerants as an effective material in enhancing thermal conditions and energy efficiency in contemporary refrigeration and HVAC systems.