US4004424A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for limiting back pressure on steam turbine
Assignee: Bechtel International Corp
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Filing: 1975-05-16
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Granted: 1977-01-25
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Expires: 1995-05-16
Abstract
Abstract Steam is removed from the steam cycle of a turbine when the back pressure on the turbine exceeds a predetermined level. Heat is then extracted from the removed steam and dissipated in a cooling tower of a cooling system for the turbine's condenser. Increased temperatures in the cooling tower augment thermal fan action, resulting in lower coolant temperatures and limiting the back pressure on the turbine. When the back pressure on the turbine decreases to an acceptable level, the steam is redirected into the steam cycle. In a preferred embodiment, heat is extracted from steam by passing the steam through the high temperature coil of a vapor-absorption generator. The high temperature vapor formed in the generator transfers the heat to the heat dissipating surfaces of a cooling tower or into heat-exchange relationship with an exhaust coolant discharged from a steam condenser. In alternative embodiments the removed steam is passed directly through an auxiliary coil in the cooling tower or through a heat exchanger that elevates the temperature of the coolant as it is passed from the condenser to the tower.
Inventors
- 👤 Aswath Maddagiri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:19
CPC Classifications
F; F01; F01K; F01K9/00; F01K9/003; F01K13/00; F01K13/02
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
107 words
An improved method for operating a steam turbine wherein a steam turbine exhaust connects to a steam condenser having a coolant circulated through a cooling tower, comprising the steps: removing steam from the steam cycle of a turbine when the back pressure on the turbine exceeds a predetermined level; extracting heat from the steam and applying the heat to the cooling tower, thereby increasing temperatures in the cooling tower, augmenting thermal fan action, lowering the coolant temperature and limiting the back pressure on the steam turbine; and redirecting the steam back into the steam cycle when the back pressure on the turbine decreases to an acceptable level.
Claim 2
Dependent Claim
107 words
An improved method for operating a steam turbine wherein a steam turbine exhaust connects to a steam condenser having a coolant circulated through a cooling tower, comprising the steps: removing steam from the steam cycle of a turbine when the back pressure on the turbine exceeds a predetermined level; extracting heat from the steam and applying the heat to the cooling tower, thereby increasing temperatures in the cooling tower, augmenting thermal fan action, lowering the coolant temperature and limiting the back pressure on the steam turbine; and redirecting the steam back into the steam cycle when the back pressure on the turbine decreases to an acceptable level.
Claim 3
Dependent Claim
26 words
The method of claim 1, wherein the extracted heat is applied to the cooling tower by increasing the temperature of coolant discharged from the steam condenser.
Claim 4
Dependent Claim
38 words
The method of claim 1, wherein the extracted heat is applied to the cooling tower by heating a vapor to high temperature, and circulating coolant discharged from the steam condenser in heat-exchange relationship with the high temperature vapor.
Claim 5
Dependent Claim
36 words
The method of claim 1, wherein the extracted heat is applied to the cooling tower by heating a vapor to high temperature, and circulating the high temperature vapor through an auxiliary coil in the cooling tower.
Claim 6
Dependent Claim
43 words
The method of claim 1, wherein the removed steam is passed through the coil of a generator in a vapor absorption cooling system that produces a high temperature vapor, and circulating the high temperature vapor in direct heat-exchange relationship with the cooling tower.
Claim 7
Dependent Claim
48 words
The method of claim 1, wherein the removed steam is passed through the high temperature coil of a generator in a vapor absorption cooling system that produces a high temperature vapor, then circulating the high temperature vapor in heat-exchange relationship with the coolant discharged from the steam condenser.
Claim 8
Dependent Claim
54 words
The method of claim 1, wherein the removed steam is passed through the high temperature coil of a generator in a vapor absorption cooling system that produces a low temperature vapor, then circulating the low temperature vapor in heat-exchange relationship with the coolant of the steam condenser as it returns from the cooling tower.
Claim 9
Dependent Claim
136 words
An improved method for operating a steam turbine cycle wherein a steam turbine exhaust connects to a steam condenser and a coolant circulates through the steam condenser and heat dissipating surfaces, comprising the steps: removing steam from the steam cycle when the back pressure on the turbine exceeds a predetermined level; passing the steam through the high temperature coil of a generator in a vapor absorption cooling system while producing a high temperature vapor; circulating the high temperature vapor of the cooling system through heat dissipating surfaces, thereby cooling the vapor to a liquid; expanding the liquid and circulating the resulting cold vapor in heat-exchange relationship to the coolant before it enters the steam condenser; and redirecting the steam back into the steam cycle when the back pressure on the turbine decreases to an acceptable level.
Claim 10
Dependent Claim
136 words
An improved method for operating a steam turbine cycle wherein a steam turbine exhaust connects to a steam condenser and a coolant circulates through the steam condenser and heat dissipating surfaces, comprising the steps: removing steam from the steam cycle when the back pressure on the turbine exceeds a predetermined level; passing the steam through the high temperature coil of a generator in a vapor absorption cooling system while producing a high temperature vapor; circulating the high temperature vapor of the cooling system through heat dissipating surfaces, thereby cooling the vapor to a liquid; expanding the liquid and circulating the resulting cold vapor in heat-exchange relationship to the coolant before it enters the steam condenser; and redirecting the steam back into the steam cycle when the back pressure on the turbine decreases to an acceptable level.
Claim 11
Independent Claim
77 words
A method for limiting back pressure on a steam turbine to maintain operability, comprising the steps: removing steam from the steam cycle of a turbine; passing the steam through the high temperature coil of a generator in a vapor absorption cooling system while producing a high temperature vapor; circulating the high temperature vapor of the cooling system through heat dissipating surfaces of a cooling tower, whereby the increased temperatures of the cooling tower augment thermal fan action.
Claim 12
Independent Claim
77 words
A method for limiting back pressure on a steam turbine to maintain operability, comprising the steps: removing steam from the steam cycle of a turbine; passing the steam through the high temperature coil of a generator in a vapor absorption cooling system while producing a high temperature vapor; circulating the high temperature vapor of the cooling system through heat dissipating surfaces of a cooling tower, whereby the increased temperatures of the cooling tower augment thermal fan action.
Claim 13
Independent Claim
106 words
A method for limiting back pressure on a steam turbine to maintain operability, comprising the steps: removing steam from the steam cycle of a turbine; passing the steam through the high temperature coil of a generator in a vapor absorption cooling system while producing a high temperature vapor; circulating the high temperature vapor of the cooling system through the high temperature coil of a heat exchanger; circulating the exhaust coolant from a steam condenser through the low temperature coil of the heat exchanger and heat dissipating surfaces of a cooling tower, whereby the increased temperatures of the coolant in the cooling tower augment thermal fan action.
Claim 14
Independent Claim
106 words
A method for limiting back pressure on a steam turbine to maintain operability, comprising the steps: removing steam from the steam cycle of a turbine; passing the steam through the high temperature coil of a generator in a vapor absorption cooling system while producing a high temperature vapor; circulating the high temperature vapor of the cooling system through the high temperature coil of a heat exchanger; circulating the exhaust coolant from a steam condenser through the low temperature coil of the heat exchanger and heat dissipating surfaces of a cooling tower, whereby the increased temperatures of the coolant in the cooling tower augment thermal fan action.
Claim 15
Dependent Claim
38 words
The method of claim 10, wherein the cooled vapor leaving the cooling tower is liquified, expanded and circulated to lower the temperatures of the coolant after it leaves the cooling tower and before it enters the steam condenser.
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) | 1980-01-25 | 1980-07-26 | 1981-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-25 | 1984-07-26 | 1985-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-25 | 1988-07-26 | 1989-01-25 | $7700.00 | Window Closed / Lapsed |