s Jalilirad - Department of Mechatronics Engineering, College of Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran
m.h Cheraghali - Department of Mechatronics Engineering, College of Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran
h Ahmadi Danesh Ashtiani - Department of Mechatronics Engineering, College of Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran

The paper studies optimization of shell-and-tube heat exchangers using the particle swarm optimization technique. A total cost function is formulated based on initial and annual operating costs of the heat exchangers. Six variables – shell inside diameter, tube diameter, baffle spacing, baffle cut, number of tube passes and tube layouts (triangular or square) – are considered as the design parameters. The particle swarm optimization selects the parameters so that the system has minimum total cost. Although generalization is not possible for any case, for minimization of cost functions of the three different cases studied in this research, larger tube outer diameter, triangular layout, baffle cut equalling 0.25 of shell diameter and one pass for each tube result in optimum designs. The other two parameters show no fixed trend

heat exchanger, shell and tube, particle swarm optimization