CCP maneuverability increasing algorithm realized on DCS with the metal allowable thermo-stressed state provision

Power generating companies' main task today is to obtain the highest possible profit. To accomplish this task, it is necessary to have maneuverable equipment that able to reach the maximum power value in minimal time and maintain metal acceptable working conditions. Metal high thermo-stressed state can lead to premature ageing and emergency situations that require investment in overhaul or replacement of units. The authors describe the method of increasing maneuverability of combined-cycle power plant. The main considered input parameter is thermo-stressed state of 'critical' elements of waste heat recovery boiler and steam turbine. Based on calculated thermo-stressed values, the algorithm informs the operator of the most optimal steam turbine loading speed. The algorithm does not require any outside software and is performed in the distributed control system installed at the power plant. Also, the authors present the power plant start-up trends with thermo-stressed state calculated values to show the stress reserve, which should be reduced, thus making the start-up faster and increasing the economic performance of the power unit.