An Experimental Approach to Minimize Entropy Generation in the Flow Condensation Inside a Horizontal Pipe

ABSTRACT The experimental investigation focuses on the two‐phase flow of nanorefrigerant in a straight tube. The vision of the study is to investigate the irreversibility of the proposed system because of frictional effects and heat transfer rate, as well as to understand the Bejan number and the extent of exergy destruction. The studies were conducted under certain conditions, involving a mass flow of about 200–500 kg/m 2 s, a vapor quality of about 0.01 to 0.9, nanoparticle volume fractions of 0.01%, 0.05%, and 0.1%, and a saturation temperature of 40.9°C. The results suggest that higher levels of vapor quality, mass flow, and MWCNT concentration are associated with reduced entropy creation related to heat transfer and increased entropy formation due to frictional pressure during the process of condensation. While the frictional entropy increases, the net entropy formation in the system is ultimately decreased and it is attributed to a considerable drop in the entropy through heat transfer, in comparison to the increase in entropy generation through friction. The Bejan number and the system's exergy loss are reduced when nanofluid is utilized. The utilization of R123‐MWCNTs nanofluid results in a significant exergy destruction of around 27%.