US4275447A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of regulation of the water level in boilers or steam generators
Assignee: Areva NP SAS
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Filing: 1979-05-11
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Granted: 1981-06-23
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Expires: 1999-05-11
Abstract
Abstract Method of regulation of the water level in boilers or steam generators, in which the inlet flow of feedwater is regulated in response to a deviation signal proportional to the difference between the real measured water level and a reference level, the proportionality factor being a linear function of the power level of the boiler with respect to the nominal power, modified by a non-linear function of ξ which preserves very low values for ξ close to zero and increases very rapidly for higher values of ξ so that the total gain is increased for low power levels and high values of ξ within a restricted range.
Inventors
- 👤 Pierre Ruiz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:17
CPC Classifications
F; F22; F22B; F22B35/00; F22B35/004
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
183 words
A method of regulation of the water level in a steam generator during the course of operation and more particularly during the starting-up phase, consisting of the steps of: measuring the water level in the steam generator, generating a signal representing the difference ξ between the real measured level of water in the steam generator and a reference level, generating a first control signal proportional to the signal representing ξ, the proportionality factor or gain being a linear function of the power level of the steam generator with respect to its nominal power, generating a second control signal representing the value--for values of ξ within a restricted range spanning the value zero --of a non-linear function preserving very low values for low values of ξ and increasing very rapidly for higher values of ξ within the restricted range, modifying said first control signal with said second signal so as to increase the total gain for low power levels and high values of ξ within the restricted range, and controlling a device for feeding water to the steam generator, with said modified control signal.
Claim 2
Independent Claim
183 words
A method of regulation of the water level in a steam generator during the course of operation and more particularly during the starting-up phase, consisting of the steps of: measuring the water level in the steam generator, generating a signal representing the difference ξ between the real measured level of water in the steam generator and a reference level, generating a first control signal proportional to the signal representing ξ, the proportionality factor or gain being a linear function of the power level of the steam generator with respect to its nominal power, generating a second control signal representing the value--for values of ξ within a restricted range spanning the value zero --of a non-linear function preserving very low values for low values of ξ and increasing very rapidly for higher values of ξ within the restricted range, modifying said first control signal with said second signal so as to increase the total gain for low power levels and high values of ξ within the restricted range, and controlling a device for feeding water to the steam generator, with said modified control signal.
Claim 3
Dependent Claim
29 words
A method of regulation as claimed in claim 1, wherein said second signal representing a function of the type ξ×f 2 (ξ) is added with the first control signal.
Claim 4
Dependent Claim
20 words
A method of regulation as claimed in claim 1, wherein the first control signal is multiplied by the second signal.
Claim 5
Dependent Claim
41 words
A method of regulation as in claim 1 or 2 or 3, wherein the non-linear function f2(ξ) is a function having odd symmetry, one for which f2(ξ)=-f2(-ξ) and the second signal is equal or proportional to the absolute value of f2(ξ).
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-06-22 | 1984-12-22 | 1985-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-22 | 1988-12-22 | 1989-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-22 | 1992-12-22 | 1993-06-23 | $7700.00 | Window Closed / Lapsed |