Dynamic optimization of startup and load-increasing processes in power plants - Part II: Application

In the first part of this study a general method for solving dynamic optimization problems has been presented: the dynamic process model, consisting of first-order ordinary differential equations, (ODEs) and algebraic equations, is discretized over the time horizon using well established methods for the solution of ODEs. The discretized system is then treated as large-scale non-linear parameter optimization problem. This transformation is implemented in a user-friendly software package. Art application of this software is demonstrated in the present paper by optimizing the process of rapid load-increase in a single-pressure combined-cycle power plant. The power plant is described with a simplified model that consists of 18 first order ordinary differential equations and 67 algebraic equations. For this model a time-optimal operation associated with a load increase from 50 percent to 75 percent of base load is calculated by considering given restrictions on some temperature gradients.