Here we report a numerical analysis of a cylindrical tube heat exchanger equipped with perforated conical rings. This study reports entropy generation, energy consumption, and thermal evaluation of heat exchanger by using ternary hybrid nanofluid (as a coolant). The nanomaterials such as Al₂O₃, Cu, and MWCNT (multi-walled carbon nanotubes) with various volume fractions (φ = 0-0.5%) are used. The mean diameter of the nanoparticles is 42 nm. The geometrical effects of perforated conical rings on the heat transfer rate, effectiveness, performance index, entropy generation, and energy consumption are discussed. The mass flow rate is varied from 0.2 kg/s to 1 kg/s. The optimum performance is highlighted with 0.5% of volume fraction along with 0.4 kg/s mass flow rate. It is noted that the entropy generation is 50% lower by using ternary hybrid nanofluid. This study enables to understand the choice of the type and volume fraction of nanoparticles and of base fluid and of the flow rate of the fluid motion.