Multi-Objective Optimization of Double-Tube Once-Through Steam Generator

Abstract

This paper presents a double-tube once-through steam generator (DOTSG) consisting of the outer straight tube and the inner helical tube. The tube length and pressure drop of are important parameters in optimal design of DOTSG. For optimal design of such a system, it was modeled to estimate its tube length and pressure drop. Pitch of inner helical tube, flow distribution ratio of the primary fluid, and tube assemblage are considered as design parameters. Then fast and elitist nondominated sorting genetic algorithm-II (NSGA-II) method was applied to find the optimum values of design parameters. In the presented optimal design approach, the tube length and the total pressure drop are two objective functions. The results of optimal designs were a set of multiple optimum solutions, called “Pareto optimal solutions.” The sensitivity analysis of change in optimum tube length and pressure drop with change in design parameters of the DOTSG is also performed and the results are reported.