Method for operating steam turbine with transient elevated back pressure
AssigneeGeneral Electric Company
InventorsMichael J. Molitor, William G. Gorman
Life of this patent
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Abstract
A method and control system can implement a transient exhaust pressure protection logic to avoid a turbine exhaust vacuum trip due to a short duration turbine exhaust pressure transient that may be caused by a large reduction in turbine flow coupled with a transient increase in exhaust pressure, which specifically occurs during full load rejections. When full load rejection conditions are sensed by power load unbalance and confirmed by secondary indications, normal alarm settings and trip settings for turbine exhaust pressure are blocked for a delay period while transient operating limits are in place.
Claims11
A method for operating a steam turbine with transient elevated exhaust pressure, the method comprising:
- operating a steam turbine according to normal alarm settings and normal trip settings for turbine exhaust pressure as a function of last stage bucket annulus velocity (VAN);
- monitoring for designated load loss conditions;
- initiating a transient exhaust pressure alarm and trip operating region under the designated load loss conditions;
- and
- operating according to a transient exhaust pressure operating region.
Dependencies are inferred from the claim text.