Evaluation of a condenser based on mini-channels technology working with R410A and R32. Experimental data and performance estimate

Abstract

In this paper, R32 is investigated as a replacement refrigerant for R410A. The Global Warming Potential (GWP) of R32 is only 675, 32% of that of R410Awhich has a GWP of 2088. Theoretical and experimental investigations are carried out on the performance of the condensation process within a mini-channel tube. Mini-channel heat exchangers technology allows reducing refrigerant charge and lets use flammable refrigerants. Due to the aspect ratio, high heat transfer coefficients are also registered.The experimental data recorded show that, for any given saturation temperature or refrigerant mass velocity, both the heat transfer coefficient and the frictional pressure gradient are always higher for R32. So, a numerical analysis based on the experimental data was developed to determinate which refrigerant performs better. The results of this numerical analysis show that, although at high refrigerant mass velocities R410A performs better, a given heat power can be always achieved with lower mass velocities and thus with a lower compressor power input when using R32. Therefore, it can be concluded that using R32 in a mini-channel condenser reduces the environmental impact and improves the energy efficiency of the system.