Thermoeconomic analysis and multiobjective optimization of tubular heat exchanger network using different shapes of nanoparticles

In this study, the effects of different nanoparticle shapes including blades, cylinders, and bricks on the thermoeconomic optimization of tubular heat exchanger (HE) networks have been studied. Boehmite alumina was used as nanoparticle and water as the base fluid. Optimal results were proposed to improve both thermal effectiveness and total annual cost simultaneously by eight design parameters. In addition, optimization was performed for four nanofluid mass flow rates, 0.5, 1, 1.5, and 2 kg/s. The results show that the application of nanoparticles was accompanied by an improvement in the thermal economic parameters of the HE network, and this improvement rate was noticeable in higher values of effectiveness. However, the results indicate a nanofluid optimal mass flow rate of 1.5 kg/s, whereas there was no significant improvement by increasing mass flow rate to 2 kg/s. The optimum results in this paper showed that the best-studied nanoparticle shape was blade, followed by brick and cylinder shapes. For example, 9.60%, 10.68%, and 11.20% improvements in the effectiveness were obtained in cylindrical, brick, and blade forms at a fixed cost of 3000 $/year, compared with BF. These improvements are 10.40%, 11.25%, and 11.52%, respectively, for the constant value of total annual cost = 4400 $/year.