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US4428190A Expired / Lapsed US ⏱️ 0.0 years remaining

Power plant utilizing multi-stage turbines

Assignee: Ormat Industries Ltd
•
Filing: 1981-08-07
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Granted: 1984-01-31
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Expires: 2001-08-07
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Abstract

Abstract A power plant includes a steam boiler that delivers a rated amount of high-pressure steam at rated temperature and pressure to a steam turbine having a high-pressure stage and at least one low-pressure stage driven by low-grade steam exhausted from the high-pressure stage. A main generator, driven by the steam turbine, furnishes electricity to a variable load. When the load decreases below rated value, the boiler operation is maintained, but low-grade steam exhausted from the high-pressure stage of the turbine is diverted from the low-pressure stage to a heat store large enough to accumulate heat during the time that the power plant operates at less than rated load. A waste heat converter, having its own generator, is responsive to the low-grade heat stored in the heat store, and can be operated selectively to furnish electricity to the load to supplement the output of the power plant. The output of the waste heat converter can be used for peak-power purposes, thereby reducing the size of the main power plant, as well as for furnishing low-level power during shutdown of the main power plant. Moreover, when in operation, the boiler and the high-pressure stage of the turbine operate at peak efficiency, which results in reducing the fuel cost of the power plant.

Inventors

  • 👤 Lucien Y. Bronicki

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 16:39
CPC Classifications
F; F01; F01K; F01K3/00; F01K3/02; F01K3/04

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 151 words
An integrated power plant comprising: (a) a steam boiler operable to deliver a rated amount of high-pressure steam at rated temperature and pressure to a steam turbine having a high-pressure stage and at least one low-pressure stage driven by low-grade steam exhausted from the high-pressure stage; (b) a main generator driven by the steam turbine for furnishing the electricity to a variable load; (c) a heat store containing water for storing low-grade heat; (d) actuatable means for selectively diverting said low-grade steam into the water of the heat store for heating the same; (e) a feed pump for removing water from the heat store and inputting it into the boiler, sufficient water being removed from the heat store to maintain the steam output of the boiler at its rated value; and (f) a waste heat converter responsive to low-grade heat in the heat store for furnishing electricity to the variable load.
Claim 2
Dependent Claim 151 words
An integrated power plant comprising: (a) a steam boiler operable to deliver a rated amount of high-pressure steam at rated temperature and pressure to a steam turbine having a high-pressure stage and at least one low-pressure stage driven by low-grade steam exhausted from the high-pressure stage; (b) a main generator driven by the steam turbine for furnishing the electricity to a variable load; (c) a heat store containing water for storing low-grade heat; (d) actuatable means for selectively diverting said low-grade steam into the water of the heat store for heating the same; (e) a feed pump for removing water from the heat store and inputting it into the boiler, sufficient water being removed from the heat store to maintain the steam output of the boiler at its rated value; and (f) a waste heat converter responsive to low-grade heat in the heat store for furnishing electricity to the variable load.
Claim 3
Dependent Claim 21 words
An integrated power plant according to claim 1 wherein the waste heat converter is a closed Rankine-cycle organic fluid power plant.
Claim 4
Dependent Claim 39 words
An integrated power plant according to claim 2 including means for monitoring the electrical load and automatically actuating said actuatable means for selectively diverting low-grade steam to the heat storage in response to the level of the electrical load.

References Cited (Backward Citations)

GB261368A Cited
GB267012A Cited
GB296023A Cited
GB964216A Cited
US3416318A Cited
US3411299A Cited
DE1959725U Cited
GB1242627A Cited
US4129004A Cited
US4089744A Cited
GB2049816B Cited
US4347706A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-01-30 1987-08-01 1988-01-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-01-30 1991-08-01 1992-01-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-01-30 1995-08-01 1996-01-31 $7700.00 Window Closed / Lapsed

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