Method of starting thermal power plant

Claim 1

A method of optimized start-up of a thermal power plant, said method comprising: (a) preparing an initial start-up schedule for a thermal power plant based on given parameters relating to operation of the thermal power plant; (b) preparing a dynamic characteristic model permitting simulation of start-up characteristics which would be obtained if the thermal power plant is started according to the initial start-up schedule; (c) estimating the energy loss in start-up of the thermal power plant and the values of selected parameters relating to operation of the thermal power plant, based on the start-up characteristics obtained from the simulation using the prepared dynamic characteristic model according to the initial start-up schedule; (d) determining whether the estimated values of the selected parameters are within predetermined allowable ranges or not; (e) correcting the initial start-up schedule according to a predetermined rule depending on whether the estimated values are determined to be within the predetermined allowable ranges or not; (f) repeating steps (c), (d), and (e) based on the corrected start-up schedule, thereby determining an optimized start-up schedule which makes the energy loss estimated by step (c) a minimum while maintaining the values of the selected parameters estimated by step (c) within the predetermined allowable ranges; (g) estimating a time required for the thermal power plant to complete its start-up operation if the optimized start-up schedule is executed; and (h) applying the optimized start-up schedule to the thermal power plant at a time preceding a given time, when it is desired that the thermal power plant completes start-up, by the time estimated by step (g).

Claim 2

A method of optimized start-up of a thermal power plant, said method comprising: (a) preparing an initial start-up schedule for a thermal power plant based on given parameters relating to operation of the thermal power plant; (b) preparing a dynamic characteristic model permitting simulation of start-up characteristics which would be obtained if the thermal power plant is started according to the initial start-up schedule; (c) estimating the energy loss in start-up of the thermal power plant and the values of selected parameters relating to operation of the thermal power plant, based on the start-up characteristics obtained from the simulation using the prepared dynamic characteristic model according to the initial start-up schedule; (d) determining whether the estimated values of the selected parameters are within predetermined allowable ranges or not; (e) correcting the initial start-up schedule according to a predetermined rule depending on whether the estimated values are determined to be within the predetermined allowable ranges or not; (f) repeating steps (c), (d), and (e) based on the corrected start-up schedule, thereby determining an optimized start-up schedule which makes the energy loss estimated by step (c) a minimum while maintaining the values of the selected parameters estimated by step (c) within the predetermined allowable ranges; (g) estimating a time required for the thermal power plant to complete its start-up operation if the optimized start-up schedule is executed; and (h) applying the optimized start-up schedule to the thermal power plant at a time preceding a given time, when it is desired that the thermal power plant completes start-up, by the time estimated by step (g).

Claim 3

A method for preparing an optimized start-up time schedule for a thermal power plant of a type in which steam admission is first made to an intermediate pressure turbine, thereby speeding up the intermediate pressure turbine, and then made to a high pressure turbine after speeding up the intermediate pressure turbine, said method comprising: (a) preparing an initial start-up time schedule defining scheduled timing of predetermined start-up operations and setting of target values required for starting the thermal power plant based on given parameters relating to the thermal power plant; (b) preparing a dynamic characteristic model permitting simulation of start-up characteristics which would be obtained if the thermal power plant is started according to the initial start-up schedule; (c) estimating a time interval between steam admission to the intermediate pressure turbine and steam admission to the high pressure turbine, and values of selected parameters including thermal stress of the thermal power plant from the simulation using the prepared dynamic characteristic model according to the initial start-up time schedule; (d) determining whether the thermal stress is within a predetermined allowable range or not; (e) correcting the initial start-up time schedule according to a predetermined rule depending on whether the thermal stress is determined to be within the predetermined allowable range or not; and (f) repeating steps (c), (d), and (e) based on the corrected start-up time schedule, thereby determining an optimized start-up time schedule which makes the time interval estimated by step (c) a minimum while maintaining the thermal stress estimated by step (c) within the predetermined allowable range.

Claim 4

A method for preparing an optimized start-up time schedule for a thermal power plant of a type in which steam admission is first made to an intermediate pressure turbine, thereby speeding up the intermediate pressure turbine, and then made to a high pressure turbine after speeding up the intermediate pressure turbine, said method comprising: (a) preparing an initial start-up time schedule defining scheduled timing of predetermined start-up operations and setting of target values required for starting the thermal power plant based on given parameters relating to the thermal power plant; (b) preparing a dynamic characteristic model permitting simulation of start-up characteristics which would be obtained if the thermal power plant is started according to the initial start-up schedule; (c) estimating a time interval between steam admission to the intermediate pressure turbine and steam admission to the high pressure turbine, and values of selected parameters including thermal stress of the thermal power plant from the simulation using the prepared dynamic characteristic model according to the initial start-up time schedule; (d) determining whether the thermal stress is within a predetermined allowable range or not; (e) correcting the initial start-up time schedule according to a predetermined rule depending on whether the thermal stress is determined to be within the predetermined allowable range or not; and (f) repeating steps (c), (d), and (e) based on the corrected start-up time schedule, thereby determining an optimized start-up time schedule which makes the time interval estimated by step (c) a minimum while maintaining the thermal stress estimated by step (c) within the predetermined allowable range.

Claim 7

A method for preparing an optimized start-up schedule for a thermal power plant, said method comprising: (a) preparing an initial start-up time schedule for starting a thermal power plant based on given parameters relating to operating of the thermal power plant; (b) estimating energy loss in the start-up of the thermal plant, a time point when the start-up of the thermal power plant will be finished, and values of selected parameters relating to operation of the thermal power plant which would be obtained if the thermal power plant is operated according to the initial start-up time schedule; (c) determining whether the estimated values of the selected parameters and the deviation of the time point from a scheduled time point for finishing the start-up of the thermal power plant are within predetermined allowable ranges or not; (d) correcting the initial start-up time schedule according to a predetermined rule depending on whether the estimated values and the deviation of the time point are determined to be within the predetermined allowable ranges or not; and (e) repeating steps (b), (c), and (d) based on the corrected start-up time schedule, thereby determining an optimized start-up time schedule which makes the energy less estimated by step (b) a minimum while maintaining the values of the selected parameters and the deviation of the time point estimated by step (b) within the predetermined allowable ranges.

Claim 8

A method for preparing an optimized start-up schedule for a thermal power plant, said method comprising: (a) preparing an initial start-up time schedule for starting a thermal power plant based on given parameters relating to operating of the thermal power plant; (b) estimating energy loss in the start-up of the thermal plant, a time point when the start-up of the thermal power plant will be finished, and values of selected parameters relating to operation of the thermal power plant which would be obtained if the thermal power plant is operated according to the initial start-up time schedule; (c) determining whether the estimated values of the selected parameters and the deviation of the time point from a scheduled time point for finishing the start-up of the thermal power plant are within predetermined allowable ranges or not; (d) correcting the initial start-up time schedule according to a predetermined rule depending on whether the estimated values and the deviation of the time point are determined to be within the predetermined allowable ranges or not; and (e) repeating steps (b), (c), and (d) based on the corrected start-up time schedule, thereby determining an optimized start-up time schedule which makes the energy less estimated by step (b) a minimum while maintaining the values of the selected parameters and the deviation of the time point estimated by step (b) within the predetermined allowable ranges.