Thermal Performance and Energy Consumption Analyses of R290 and R22 Refrigerants in Air-conditioning System

The study investigated the comparative performance of R290 and R22 refrigerants in a domestic air-conditioning system. It used a 2 hp window split air-conditioning system with Capella D oil as lubricant. Performance analysis which include coefficient of performance, cooling capacity, energy consumption and thermal conductivity and viscosity at vapour and liquid phases were determined. The results were employed to carry out the comparative analyses of the efficiency of R290 as a replacement alternative to R22 refrigerant in a domestic air-conditioning unit. The findings show that although R22 performed better in terms of its coefficient of performance and cooling capacity, R290 however showed better results in terms of its energy consumption, thermal conductivity and viscosity at the liquid and vapour phases. Further to this, there is no marked difference in the pull-down time results. The consequence of the results is that R290 can be a suitable alternative air-conditioning refrigerant to R22, the performance notwithstanding. However, the performance can be further improved with a reconfiguration of the thermo-physical properties of the thermodynamic system such as the lubricant. This can be achieved by taking advantage of the ability of metallic and non-metallic nanoparticles to improve the thermal and physical properties of the lubricant and by extension the thermodynamic system. Thus, with improvement in the thermal conductivity and viscosity of the lubricant, there can be further improvement in the performance of R290 as air-conditioning refrigerant. Going by the findings and coupled with the fact that R22 is environmentally malignant, R290 can become a suitable alternative in the long run. (paper)