Steam-turbine damage-evaluation apparatus, steam-turbine damage-evaluation method, and steam-turbine damage-evaluation program
A damage evaluation apparatus includes an acquisition unit configured to acquire a plurality of detection data from a plurality of sensors installed in a steam turbine, a calculation unit configured to calculate the operating state quantity of a nozzle diaphragm in the steam turbine based on a plurality of detection data, a computation unit configured to compute the creep deformation velocity of the nozzle diaphragm based on the operating state quantity, and an estimation unit configured to estimate the deformation amount of the nozzle diaphragm based on the creep deformation velocity according to a future operation plan for the steam turbine.
1 . A steam-turbine damage-evaluation apparatus configured to evaluate behavior of a nozzle diaphragm of a steam turbine, comprising:
an acquisition unit configured to acquire a plurality of detection data from a plurality of sensors attached to the steam turbine and its periphery at predetermined positions;
a calculation unit configured to calculate operating state quantity of the nozzle diaphragm of the steam turbine based on the plurality of detection data;
a computation unit configured to compute creep deformation velocity of the nozzle diaphragm based on the operating state quantity; and
an estimation unit configured to estimate a deformation amount of the nozzle diaphragm based on the creep deformation velocity according to a future operation plan for the steam turbine,
wherein the plurality of sensors is configured to detect the plurality of detection data with respect to at least one of a steam inlet side and a steam outlet side of the steam turbine and an extracted steam from the steam turbine, and
wherein the calculation unit is configured to calculate the operating state quantity according to a heat balance of the steam turbine, which reflects temperature at the steam inlet side and the steam outlet side of the steam turbine, based on the plurality of detection data.
2 . The steam-turbine damage-evaluation apparatus according to claim 1 , wherein the creep deformation velocity is computed based on historical data representing the plurality of detection data detected in past in addition to the plurality of detection data detected in real time.
3 . The steam-turbine damage-evaluation apparatus according to claim 2 , wherein the historical data are provided externally.
4 . The steam-turbine damage-evaluation apparatus according to claim 1 , wherein the creep deformation velocity is computed based on an equivalent stress of the nozzle diaphragm derived from the operating state quantity.
5 . The steam-turbine damage-evaluation apparatus according to claim 1 , further comprising an evaluation unit configured to evaluate a damage risk of the nozzle diaphragm based on the deformation amount of the nozzle diaphragm estimated by the estimation unit.
6 . The steam-turbine damage-evaluation apparatus according to claim 5 , wherein an occurrence frequency is determined with respect to the deformation amount of the nozzle diaphragm, which is varied responsive to the creep deformation velocity having a probability distribution relative to an equivalent stress of the nozzle diaphragm and an operation time of the steam turbine, thus evaluating the damage risk of the nozzle diaphragm based on the occurrence frequency.
7 . The steam-turbine damage-evaluation apparatus according to claim 5 , wherein the damage risk is evaluated by correcting an estimated value of the deformation amount of the nozzle diaphragm, which is estimated by the estimation unit based on the creep deformation velocity, with a measured value of the nozzle diaphragm.
8 . A steam-turbine damage-evaluation method for evaluating behavior of a nozzle diaphragm of a steam turbine, comprising:
acquiring a plurality of detection data from a plurality of sensors attached to the steam turbine and its periphery at predetermined positions;
calculating operating state quantity of the nozzle diaphragm of the steam turbine based on the plurality of detection data;
computing creep deformation velocity of the nozzle diaphragm based on the operating state quantity; and
estimating deformation amount of the nozzle diaphragm based on the creep deformation velocity according to a future operation plan for the steam turbine,
wherein the plurality of sensors is configured to detect the plurality of detection data with respect to at least one of a steam inlet side and a steam outlet side of the steam turbine and an extracted steam from the steam turbine, and
wherein the operating state quantity is calculated according to a heat balance of the steam turbine, which reflects temperature at the steam inlet side and the steam outlet side of the steam turbine, based on the plurality of detection data.
9 . A non-transitory computer-readable storage medium storing a steam-turbine damage-evaluation program adapted to a steam-turbine damage-evaluation apparatus configured to evaluate behavior of a nozzle diaphragm of a steam turbine, the steam-turbine damage-evaluation program being executable by at least one processor to perform steps of:
acquiring a plurality of detection data from a plurality of sensors attached to the steam turbine and its periphery at predetermined positions;
calculating operating state quantity of the nozzle diaphragm of the steam turbine based on the plurality of detection data;
computing creep deformation velocity of the nozzle diaphragm based on the operating state quantity; and
estimating deformation amount of the nozzle diaphragm based on the creep deformation velocity according to a future operation plan for the steam turbine,
wherein the plurality of sensors is configured to detect the plurality of detection data with respect to at least one of a steam inlet side and a steam outlet side of the steam turbine and an extracted steam from the steam turbine, and
wherein the operating state quantity is calculated according to a heat balance of the steam turbine, which reflects temperature at the steam inlet side and the steam outlet side of the steam turbine, based on the plurality of detection data.