Akimasa Nakai

Turbine Start-Up Algorithm Based on Prediction of Rotor Thermal Stress

Abstract This paper presents a time-optimal control algorithm of a thermal power plant based on prediction of rotor thermal stress. In a thermal power plant, a controller is required to minimize the start-up time with limiting rotor thermal stress to the acceptable value. To achieve the contradictive control objectives, the new control algorithm based on a model predictive control is proposed. The algorithm predicts the future thermal stress on the rotor and calculates the optimal future profile of the steam flow rate in every control interval. Numerical examples show the effectiveness of the algorithm.

A new control strategy for coal fired thermal power plants

This paper presents a coordinated controller parameter adjusting method for boilers. The method includes constructing a simplified engineering boiler model and adjusting controller parameters with nonlinear constrained optimization. Because many control loops in the generation plants interfere with each other, the improvement in the control ability by the method is remarkable. Simulation results are shown in the paper

Turbine start-up algorithm based on prediction of rotor thermal stress

This paper presents a control algorithm for a time-optimal control of a thermal power plant based on predictive control. In a thermal power plant the temperature between the hot steam and the cold rotor causes the thermal stress. The excess thermal stresses shorten the life span of the steam turbine rotor and restrict the start up time of the plant. The control algorithm designed by a model predictive control method calculates the optimal future profile of the steam flow rate at every control interval. The actual steam flow rate is controlled to the optimal profile which enables start up of the turbine in the shortest period keeping the thermal stress under the allowable value. Numerical examples show the effectiveness of the algorithm.