Effect of pressure drop and longitudinal conduction on exergy destruction in a concentric-tube micro-fin tube heat exchanger

A numerical study is carried out to predict the heat transfer characteristics and various exergy losses in a micro-fin concentric-tube double pipe heat exchanger. The results are compared with the experimental data from the literature and are found to be in a good agreement. The study is extended to include the effect of pressure drop and longitudinal conduction on the exergy losses. Furthermore, Ethylene Glycol-Water as a hot fluid is considered to investigate the effect of higher viscosity on the frictional irreversible losses. It is found that, at lower mass flow rates, fluid frictional irreversibility can be ignored for a low viscous fluid; however, there is a substantial exergy loss for a highly viscous fluid. At higher mass flow rates, fluid frictional irreversibility dominates over thermal irreversibility for both the fluids investigated in this study.