US3802189A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Boiler-turbine control system
Assignee: Leeds and Northrup Co
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Filing: 1972-01-13
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Granted: 1974-04-09
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Expires: 1992-01-13
Abstract
Abstract A system for providing a demand signal to control the boiler inputs in a boiler-turbine combination operating in a sliding pressure mode with the throttle valve being controlled to maintain the desired generator output. The demand signal for the boiler inputs is obtained by multiplying the ratio of first stage turbine pressure to throttle pressure by the throttle pressure set point and the throttle pressure set point is controlled so as to maintain the ratio at a preset value. The demand signal is modified to trim the boiler inputs to maintain the throttle pressure at its set point.
Inventors
- 👤 T Jenkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:56
CPC Classifications
F; F01; F01K; F01K7/00; F01K7/10; F01K7/12; F01K7/14; F01K13/00; F01K13/02; F23; F23N; F23N1/00; F23N1/08; F23N1/082; F23N2223/00; F23N2223/12; F23N2223/14; F23N5/00; F23N5/18
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
116 words
In a control system for a turbine-generator unit which adjusts a control valve controlling the steam flow to the turbine to tend to maintain a desired power level in the turbinegenerator unit, and adjusts the inputs to the boiler in accordance with a demand signal computer as the ratio of a signal representing said steam flow to a signal representing boiler output steam pressure all multiplied by a set point for said pressure with means for modifying the demand signal until the throttle pressure returns to a predetermined set point, the combination therewith of: means operable to modify the throttle pressure set point until the measured state of the control valve corresponds to the desired state.
Claim 2
Dependent Claim
116 words
In a control system for a turbine-generator unit which adjusts a control valve controlling the steam flow to the turbine to tend to maintain a desired power level in the turbinegenerator unit, and adjusts the inputs to the boiler in accordance with a demand signal computer as the ratio of a signal representing said steam flow to a signal representing boiler output steam pressure all multiplied by a set point for said pressure with means for modifying the demand signal until the throttle pressure returns to a predetermined set point, the combination therewith of: means operable to modify the throttle pressure set point until the measured state of the control valve corresponds to the desired state.
Claim 3
Dependent Claim
165 words
In a system for controlling the inputs to a boiler of a boiler-turbine system in response to a demand signal calculated as the product of a signal representing a set point for the pressure of steam supplied by the boiler and a signal representing the ratio of a signal representing the steam flow in the turbine to a signal representing the measured value of said pressure with means for modifying said demand signal until said measured pressure returns to said set point, and with a control valve controlling the steam flow to the turbine being controlled to maintain a desired power level in the turbine-generator unit, the combination therewith of: means for producing a signal representative of a desired state of said control valve, means for comparinG said last named signal with said ratio, and means for controlling said set point signal so as to modify said demand signal in a direction and extent to tend to maintain said control valve in said desired state.
Claim 4
Dependent Claim
165 words
In a system for controlling the inputs to a boiler of a boiler-turbine system in response to a demand signal calculated as the product of a signal representing a set point for the pressure of steam supplied by the boiler and a signal representing the ratio of a signal representing the steam flow in the turbine to a signal representing the measured value of said pressure with means for modifying said demand signal until said measured pressure returns to said set point, and with a control valve controlling the steam flow to the turbine being controlled to maintain a desired power level in the turbine-generator unit, the combination therewith of: means for producing a signal representative of a desired state of said control valve, means for comparinG said last named signal with said ratio, and means for controlling said set point signal so as to modify said demand signal in a direction and extent to tend to maintain said control valve in said desired state.
Claim 5
Independent Claim
184 words
The method for automatically controlling inputs to a boiler-turbine system so as to tend to maintain a throttle valve controlling steam flow to the turbine in a predetermined state when said valve is subject to control to maintain a desired power output from a generator driven by said turbine comprising the steps of: producing a demand signal in accordance with the ratio of a signal representing steam flow to the turbine with respect to a signal representing the measured throttle pressure at the boiler output all multiplied by a signal representing throttle pressure set point, producing a signal representative of the desired state of the throttle valve, producing a signal representative of the actual state of the throttle valve, comparing said signals representative of the desired and actual throttle valve states, modifying the signal representative of said throttle pressure set point so as to tend to reduce the deviation between said compared signals, modifying the demand signal so as to tend to maintain the said throttle pressure at its modified set point, and controlling the boiler inputs in accordance with said modified demand signal.
Claim 6
Independent Claim
184 words
The method for automatically controlling inputs to a boiler-turbine system so as to tend to maintain a throttle valve controlling steam flow to the turbine in a predetermined state when said valve is subject to control to maintain a desired power output from a generator driven by said turbine comprising the steps of: producing a demand signal in accordance with the ratio of a signal representing steam flow to the turbine with respect to a signal representing the measured throttle pressure at the boiler output all multiplied by a signal representing throttle pressure set point, producing a signal representative of the desired state of the throttle valve, producing a signal representative of the actual state of the throttle valve, comparing said signals representative of the desired and actual throttle valve states, modifying the signal representative of said throttle pressure set point so as to tend to reduce the deviation between said compared signals, modifying the demand signal so as to tend to maintain the said throttle pressure at its modified set point, and controlling the boiler inputs in accordance with said modified demand signal.
Claim 7
Dependent Claim
28 words
The method of claim 3 in which the signal representative of the actual state of said throttle valve is produced in accordance with the pressure difference across it.
Claim 8
Dependent Claim
46 words
The method of claim 3 in which the signal representative of the actual state of said throttle valve is representative of the opening in said valve and is established by the ratio of said signal representing steam flow and said signal representing the actual throttle pressure.
Claim 9
Dependent Claim
42 words
The method of claim 3 in which the modification of the signal representative of the throttle pressure set point is produced by control action having a proportional and integral function which control action is responsive to the deviation of said compared signals.
Claim 10
Dependent Claim
26 words
The method of claim 6 in which the control action is responsive to said deviation times a signal representative of the desired output of said generator.
Claim 11
Dependent Claim
33 words
The method of claim 6 in which the control action is responsive to said deviation plus a signal representative of the difference between the desired output of said generator and its measured output.
Claim 12
Dependent Claim
49 words
The method of claim 6 in which the control action is responsive to said deviation times a signal representative of the desired output of said generator with the addition to the resulting product of a signal representative of the difference between the desired and measured outputs of said generator.
Claim 13
Dependent Claim
38 words
The method of claim 6 in which the modification of the signal representative of the throttle pressure set point by said control action includes the addition to said control action of a signal representative of the desired generation.
Claim 14
Dependent Claim
66 words
The method of claim 6 in which the control action is responsive to said deviation times a signal representative of the desired output of said generator with the addition to the resulting product of a signal representative of the difference between the desired and measured outputs of said generator and the control action is modified by the addition of said signal representative of the desired output.
References Cited (Backward Citations)
US3247671A
Cited
US3545207A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-08 | 1977-10-08 | 1978-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-08 | 1981-10-08 | 1982-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-08 | 1985-10-08 | 1986-04-09 | $7700.00 | Window Closed / Lapsed |