US4358930A
Expired / Lapsed
US
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Method of optimizing performance of Rankine cycle power plants
Assignee: United States Department of Energy
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Filing: 1980-06-23
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Granted: 1982-11-16
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Expires: 2000-06-23
Abstract
Abstract A method for efficiently operating a Rankine cycle power plant (10) to maximize fuel utilization efficiency or energy conversion efficiency or minimize costs by selecting a turbine (22) fluid inlet state which is substantially in the area adjacent and including the transposed critical temperature line (46).
Inventors
- 👤 William L. Pope
- 👤 Howard S. Pines
- 👤 Padraic A. Doyle
- 👤 Lenard F. Silvester
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:06
CPC Classifications
F; F01; F01K; F01K25/00; F01K25/08; F01K25/06; F03; F03G; F03G4/00; F03G4/001; F03G4/031; F03G4/033; F03G4/035; F03G4/037; F03G4/074; Y; Y02; Y02E; Y02E20/00; Y02E20/16
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
51 words
A method for operating a turbine to maximize energy conversion and/or fuel utilization efficiency including the step of: expanding working fluid in a turbine with a turbine fluid inlet state which is substantially in the supercritical vapor region and substantially where the specific heat of the working fluid is a maximum.
Claim 2
Independent Claim
51 words
A method for operating a turbine to maximize energy conversion and/or fuel utilization efficiency including the step of: expanding working fluid in a turbine with a turbine fluid inlet state which is substantially in the supercritical vapor region and substantially where the specific heat of the working fluid is a maximum.
Claim 3
Independent Claim
47 words
A method for operating a turbine to maximize energy conversion and/or fuel utilization efficiency including the step of: expanding working fluid in a turbine with a turbine fluid inlet state which is substantially in the area adjacent and including the transposed critical temperature line of the fluid.
Claim 4
Independent Claim
47 words
A method for operating a turbine to maximize energy conversion and/or fuel utilization efficiency including the step of: expanding working fluid in a turbine with a turbine fluid inlet state which is substantially in the area adjacent and including the transposed critical temperature line of the fluid.
Claim 5
Independent Claim
66 words
A method for operating a binary Rankine cycle power plant to maximize energy conversion and/or fuel utilization efficiency including the steps of: vaporizing a working fluid in a supercritical heat exchanger; and expanding the working fluid in a turbine with a turbine fluid inlet state which is substantially in the supercritical vapor region and substantially where the specific heat of the working fluid is a maximum.
Claim 6
Independent Claim
66 words
A method for operating a binary Rankine cycle power plant to maximize energy conversion and/or fuel utilization efficiency including the steps of: vaporizing a working fluid in a supercritical heat exchanger; and expanding the working fluid in a turbine with a turbine fluid inlet state which is substantially in the supercritical vapor region and substantially where the specific heat of the working fluid is a maximum.
Claim 7
Independent Claim
66 words
A method for operating a power plant to maximize energy conversion and/or fuel utilization efficiency including the steps of: vaporizing a working fluid in a heat exchanger to supercritical exit conditions; and expanding the working fluid in a turbine with a turbine fluid inlet state which is substantially in the supercritical vapor region and substantially where the specific heat of the working fluid is a maximum.
Claim 8
Independent Claim
66 words
A method for operating a power plant to maximize energy conversion and/or fuel utilization efficiency including the steps of: vaporizing a working fluid in a heat exchanger to supercritical exit conditions; and expanding the working fluid in a turbine with a turbine fluid inlet state which is substantially in the supercritical vapor region and substantially where the specific heat of the working fluid is a maximum.
Claim 9
Independent Claim
56 words
A method for operating a power plant to maximize energy conversion and/or fuel utilization efficiency, including the steps of: vaporizing a fluid in a heat exchanger; and expanding the fluid in a turbine with a turbine fluid inlet state which is substantially in the area adjacent and including the transposed critical temperature line of the fluid.
Claim 10
Independent Claim
56 words
A method for operating a power plant to maximize energy conversion and/or fuel utilization efficiency, including the steps of: vaporizing a fluid in a heat exchanger; and expanding the fluid in a turbine with a turbine fluid inlet state which is substantially in the area adjacent and including the transposed critical temperature line of the fluid.
Claim 11
Dependent Claim
138 words
The method of claim 5 wherein the step of expanding the fluid in a turbine with a turbine fluid inlet state which is substantially in the area adjacent and including the transposed critical temperature line of the fluid includes the step of expanding the fluid in a turbine with the turbine fluid inlet state such that the turbine inlet state on a pressure-enthalpy graph has substantially the following boundaries; (1) the constant critical temperature line; (2) the critical pressure line; (3) the line of constant specific volume extending from the intersection of the critical pressure line and the maximum constant specific enthalpy line tangent to the vapor saturation boundary; (4) the constant temperature line which is 20% above the critical temperature line; and (5) the line of constant specific volume which is 20% below the critical specific volume.
Claim 12
Independent Claim
71 words
A method for operating a Rankine cycle power plant to maximize thermodynamic and economic performance including the steps of: vaporizing a fluid in a supercritical primary heater; expanding the fluid in a turbine with a turbine fluid inlet state which is substantially in the area adjacent and including the transposed critical temperature line of the fluid; and condensing the fluid exhausted from the turbine; returning the condensed fluid to the heater.
Claim 13
Independent Claim
71 words
A method for operating a Rankine cycle power plant to maximize thermodynamic and economic performance including the steps of: vaporizing a fluid in a supercritical primary heater; expanding the fluid in a turbine with a turbine fluid inlet state which is substantially in the area adjacent and including the transposed critical temperature line of the fluid; and condensing the fluid exhausted from the turbine; returning the condensed fluid to the heater.
Claim 14
Dependent Claim
138 words
The method of claim 7 wherein the step of expanding the fluid in a turbine with a turbine fluid inlet state which is substantially in the area adjacent and including the transposed critical temperature line of the fluid includes the step of expanding the fluid in a turbine with the turbine fluid inlet state such that the turbine inlet state on a pressure-enthalpy graph has substantially the following boundaries: (1) the constant critical temperature line; (2) the critical pressure line; (3) the line of constant specific volume extending from the intersection of the critical pressure line and the maximum constant specific enthalpy line tangent to the vapor saturation boundary; (4) the constant temperature line which is 20% above the critical temperature line; and (5) the line of constant specific volume which is 20% below the critical specific volume.
Claim 15
Dependent Claim
54 words
The method of claim 7, wherein the fluid has a vapor saturation boundary as defined on a pressure-enthalpy diagram, including the step of selecting the fluid to have a vapor saturation boundary which is at least in part parallel to the condition, as represented on the pressure-enthalpy diagram, of fluid expanding in the turbine.
Claim 16
Dependent Claim
24 words
The method of claim 7 including the step of selecting the fluid so that there is substantially dry expansion of fluid in the turbine.
Claim 17
Dependent Claim
29 words
The method of claim 7 including the step of selecting the working fluid so that particular chemical reactions can be avoided that would accelerate fouling in the primary heater.
Claim 18
Dependent Claim
53 words
The method of claim 7, wherein the Rankine cycle power plant uses geothermal brine and has a brine disposal system, including the steps of heating the working fluid with geothermal brine and selecting the working fluid so that particular chemical reactions can be avoided that could cause clogging in the brine disposal system.
Claim 19
Dependent Claim
21 words
The method of claim 7 including the step of: using a working fluid composed of a mixture of isobutane and isopentane.
Claim 20
Dependent Claim
31 words
The method of claim 7 including the step of: using a working fluid selected from the group consisting of methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, and neopentane and mixtures thereof.
Claim 21
Dependent Claim
21 words
The method of claim 7 including the step of: using a working fluid composed of a mixture of Pyridine and water.
Claim 22
Dependent Claim
17 words
The method of claim 7 including the step of: using a working fluid composed of an azeotrope.
Claim 23
Dependent Claim
23 words
The method of claim 7 including the step of: vaporizing the fluid in the heater with heat rejected from a higher temperature process.
Claim 24
Dependent Claim
33 words
The method of claim 7 including the step of: using the vaporizing, selecting, expanding, condensing and returning steps as a bottoming cycle for efficiently using waste heat rejected from a higher temperature process.
Claim 25
Dependent Claim
37 words
The method of claim 7 including the step of: using the vaporizing, selecting, expanding, condensing and returning steps as a topping cycle rejecting heat to a lower temperature cycle to increase overall power output and process efficiency.
Claim 26
Dependent Claim
46 words
The method of claim 7 wherein the vaporized fluid is a working fluid and including the steps of: vaporizing the working fluid in the heater with a source fluid; and changing the composition of the working fluid responsive to a declining temperature of the source fluid.
Claim 27
Dependent Claim
21 words
The method of claim 20 including the step of: using a working fluid composed of a mixture of isobutane and isopentane.
Claim 28
Dependent Claim
31 words
The method of claim 20 including the step of: using a working fluid selected from the group consisting of methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, and neopentane and mixtures thereof.
Claim 29
Dependent Claim
21 words
The method of claim 20 including the step of using a working fluid composed of a mixture of Pyridine and water.
Claim 30
Dependent Claim
30 words
The method of claim 7 including the step of: changing the composition of the fluid to maintain a desired turbine inlet state as the primary heater degrades due to fouling.
Claim 31
Dependent Claim
44 words
The method of claim 7 wherein the Rankine cycle power plant uses geothermal brine and has geothermal brine injection wells including the step of: changing the composition of the fluid to maintain a desired turbine inlet state as clogging increases in the injection wells.
Claim 32
Dependent Claim
49 words
The method of claim 7 wherein the Rankine cycle power plant uses geothermal brine and has geothermal brine injection wells including the step of changing the turbine inlet operating conditions to another point in the area adjacent and including the transposed critical temperature line as brine injection characteristics change.
Claim 33
Dependent Claim
27 words
The method of claim 7 including the step of: co-generating electric power and mechanical work or process heat from the step of expanding fluid in the turbine.
Claim 34
Dependent Claim
31 words
The method of claim 7, wherein the environment is used as a heat sink, including the step of: selecting turbine characteristics to minimize efficiency degradation in response to heat sink variations.
Claim 35
Dependent Claim
27 words
The method of claim 7 including the step of: selecting turbine characteristics to minimize efficiency degradation as the power output requirements of the power plant are reduced.
Claim 36
Dependent Claim
41 words
The method of claim 7, wherein the Rankine cycle power plant uses geothermal brine from a geothermal brine source including the step of: selecting turbine characteristics to minimize efficiency degradation in response to a temperature decline in the geothermal brine source.
Claim 37
Dependent Claim
16 words
The method of claim 7 including the step of: using a working fluid comprising an olefin.
Claim 38
Dependent Claim
18 words
The method of claim 7 including the step of: using a working fluid comprising a saturated light hydrocarbon.
Claim 39
Dependent Claim
18 words
The method of claim 7 including the step of: using a working fluid comprising hydrocarbons and mixtures thereof.
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) | 1985-11-15 | 1986-05-17 | 1986-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-15 | 1990-05-17 | 1990-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-15 | 1994-05-17 | 1994-11-16 | $7700.00 | Window Closed / Lapsed |