Multi-Objective Optimization System for Plant Layout Design (2nd Report, Application of Particle Swarm Optimization to Automatic Placement and Adjustment of Plant Systems)

Abstract

It is difficult for a designer to optimize a plant layout design because the related decision making involves multiple objectives and constraints such as safety, economic costs, maintainability, and construction term of works. In order to support the designer's decision making, we have developed a multi-objective optimization system for plant layout design; this system involves an effective interaction between the designer and the computer. In this paper, we have proposed a hybrid optimization technique for plant layout design using a genetic algorithm (GA) and particle swarm optimization (PSO). In the first step, the designer globally searches for a layout solution on the basis of a coding rule of the GA proposed in the first report. However, the obtained layout solution in this step is rough and is not adequately optimal because the GA is a combinatorial optimization algorithm that uses discrete design variables. Then, in the second step, the obtained layout solution is automatically corrected toward a better position by using a modified PSO algorithm for continuance design variables. The proposed method is applied to the layout design of an actual power plant in order to demonstrate the validity of this approach.