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US 4,053,745 AGranted
Valve contingency detection system for a turbine power plant
AssigneeWestinghouse Electric Corp.
InventorsLeaman B. Podolsky, Charles L. Groves, Jr.
Life of this patent
Estimating the term…
Abstract
A system for detecting the failure of steam inlet valves to respond properly to their respective control signals, is disclosed. The detection of such a contingency provides an appropriate indication, and also initiates a transfer to single valve operation when operating in the sequential valve mode. The system provides for indicating and/or transferring to single valve operations only after the contingency has been detected for a predetermined interval to compensate for the velocity limiting characteristics of the valve actuators.
Claims11
A steam turbine system, comprising
- a plurality of steam inlet valves for governing the admission of steam to the turbine,
- means to generate an electrical representation of a desired valve position for each of the steam inlet valves,
- means to control each of the steam inlet valves in accordance with the desired valve position representation,
- means to generate an electrical representation of actual valve position for each of the steam inlet valves,
- means when activated to generate a contingency output representation for each of the steam inlet valves,
- means to compare the representations of actual and desired position for each of the steam inlet valves,
- means governed by the compared representation to initiate a predetermined time duration for each valve at times when the actual and desired representations of a respective valve differ by a predetermined value,
- means governed by the comparison means to activate the contingency output generating means in response to a compared difference of said predetermined value at the termination of the initiated time duration period for each valve, and
- means governed by the activated contingency generating output means for each valve to indicate a contingency for such associated valve.
6 more elements
A steam turbine system, comprising
- a plurality of steam inlet valves to control the flow of steam to the turbine;
- means to control the desired position of each of the valves in accordance with an electrical signal;
- means to generate an electrical analog signal corresponding to the actual position of each valve;
- a contingency indicator for each of the valves effective when activated to indicate the failure of an associated valve to respond to its respective positioning signal;
- means to convert a generated digital representation of desired valve position to govern the value of the analog signal for controlling desired position of each valve;
- means to convert the analog signal of actual valve position to a corresponding digital representation;
- calculating means including sequencing means having the following components,
- a. means to generate for each valve the digital representation of desired valve position,
- b. means to compare repetitively at predetermined time intervals, the value of the digital representation of desired valve position with the digital representation of actual valve position for each of the plurality valves,
- c. a counting means governed by the comparison means to count in one direction at each said time interval at times when the compared representations differ by a predetermined value and to reset in the other direction at each said interval at times when the compared representatives differ less than a predetermined value,
- d. a contingency output generating means operative when activated to detect a failure of a respective valve to respond to its desired position representation,
- e. means governed by the counting means to activate the output generating means at each predetermined interval at times when the counting means is operated to a predetermined count in the one direction;
- and
- means responsive to the activated detection means to indicate the failure of a respective valve.
11 more elements
Dependencies are inferred from the claim text.