Cyclic Cleaning Scheduling of Industrial Boiler Based on Steepest Descent Approximate Linear Programming

In this paper, the planning for the multi-period cleaning of an industrial boiler is formulated as a mixed-integer nonlinear program (MINLP). The objective function accounted for both the cost of fuel consumption and boiler cleaning & maintenance costs. And a subsection method was proposed for solving the MINLP problem using the steepest descent approximate linear programming (SDALP), which exhibits the advantages of the approximate linear programming (ALP) algorithm, such as easy implementation and convenient solution, and then introduces the principle of purposeful search and rapid convergence via the steepest descent method. This new method can eliminate the negative effect of the subjective step restriction and reduction coefficient, improve the convergence speed, and enhance the solution accuracy. The computation time for the method was proportional to the number of periods, and global solution of the MINLP was guaranteed. At last, the effectiveness of the proposed method was illustrated with an example.