Patent US4050418A successfully refreshed from Google Patents.
US4050418A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system for steam generator
Assignee: Hitachi Ltd
•
Filing: 1975-07-08
•
Granted: 1977-09-27
•
Expires: 1995-07-08
Abstract
Abstract Heat produced in a fast breeder reactor is introduced out of the reactor by liquid sodium into an intermediate heat-exchanger where the heat is transferred to the secondary coolant sodium. In an evaporator, vapor is generated by heat-exchange between the secondary coolant sodium and feed-water supplied thereto through a feed-water valve. In a superheater, superheated vapor is obtained through heat-exchange between the secondary coolant sodium and the vapor supplied from the evaporator. The superheated vapor is introduced into a turbine to drive the same. A permissible vapor temperature which is higher than a saturated temperature is established in dependence on the vapor pressure at the outlet of the evaporator. The flow rate of the feed-water is reduced by closing the feed-water valve when the vapor temperature at the outlet of the evaporator is close to the saturated temperature. The result is that the super-heater is prevented from suffering from the damage of liquid water because the super-heater is weak in liquid water.
Inventors
- 👤 Takao Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:20
CPC Classifications
G; G21; G21D; G21D3/00; G21D3/08; F; F22; F22B; F22B35/00; F22B35/004; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
143 words
In a steam generator having an evaporator for producing steam by heat-exchange between alkaline metal and feed-water and a super-heater for further heating the steam by heat-exchange between the steam produced by said evaporator and alkaline metal, an improved control system for the steam generator comprising: a vapor temperature detector for detecting the vapor temperature at the outlet of said evaporator; a vapor pressure detector for detecting the vapor pressure at the outlet of said evaporator; first means receiving the outputs of said vapor temperature detector and said vapor pressure detector to thereby detect the fact that the vapor is in such a condition that liquid water may possibly enter into said super-heater and produce an output; and second means for reducing the flow rate of the feed-water to be supplied to said evaporator, in response to the output of said first means.
Claim 2
Dependent Claim
143 words
In a steam generator having an evaporator for producing steam by heat-exchange between alkaline metal and feed-water and a super-heater for further heating the steam by heat-exchange between the steam produced by said evaporator and alkaline metal, an improved control system for the steam generator comprising: a vapor temperature detector for detecting the vapor temperature at the outlet of said evaporator; a vapor pressure detector for detecting the vapor pressure at the outlet of said evaporator; first means receiving the outputs of said vapor temperature detector and said vapor pressure detector to thereby detect the fact that the vapor is in such a condition that liquid water may possibly enter into said super-heater and produce an output; and second means for reducing the flow rate of the feed-water to be supplied to said evaporator, in response to the output of said first means.
Claim 3
Dependent Claim
89 words
The improvement according to claim 1, wherein said first means includes: third means for establishing a permissible lower limit temperature which is higher than the saturation temperature corresponding to the detected vapor pressure, in response to the output of said vapor pressure detector; and fourth means for comparing the output of said third means with the output of said vapor temperature detector to produce an output when the vapor temperature at the outlet of said evaporator becomes lower than the permissible lower limit temperature established by said third means.
Claim 4
Dependent Claim
28 words
The improvement according to claim 1, further comprising: fifth means for controlling the flow rate of the feedwater in the absence of the output of said first means.
Claim 5
Dependent Claim
28 words
The improvement according to claim 2, further comprising: fifth means for controlling the flow rate of the feedwater in the absence of the output of said first means.
Claim 6
Dependent Claim
86 words
The improvement according to claim 3, in which said fifth means includes: sixth means for detecting the output of said steam generator; seventh means for establishing a reference value of the output of said steam generator; an adder for obtaining the difference between the respective outputs of said sixth and seventh means; and an adjuster for producing an output in accordance with the output of said adder to thereby control the flow rate of the feed-water in the absence of the output of said first means.
Claim 7
Dependent Claim
86 words
The improvement according to claim 4, in which said fifth means includes: sixth means for detecting the output of said steam generator; seventh means for establishing a reference value of the output of said steam generator; an adder for obtaining the difference between the respective outputs of said sixth and seventh means; and an adjuster for producing an output in accordance with the output of said adder to thereby control the flow rate of the feed-water in the absence of the output of said first means.
Claim 8
Dependent Claim
94 words
The improvement according to claim 3, in which said fifth means includes: eighth means for detecting the vapor temperature at the outlet of said steam generator; ninth means for establishing a reference value of the vapor temperature at the outlet of said steam generator; an adder for obtaining the difference between the respective outputs of said eighth and ninth means; and an adjuster for producing an output in accordance with the output of said adder to thereby control the flow rate of the feed-water in the absence of the output of said first means.
Claim 9
Dependent Claim
91 words
The improvement according to claim 4, said fifth means includes: eighth means for detecting the vapor temperature at the outlet of said steam generator; ninth means for establishing a reference value of the vapor temperature at the outlet of said steam generator; an adder for obtaining the difference between the respective outputs of said eighth and ninth means; and an adjuster for producing an output in accordance with the output of said adder to thereby control the flow rate of the feed-water in absence of the output of said first means.
Claim 10
Dependent Claim
170 words
The improvement according to claim 3, in which said fifth means includes: tenth means for detecting the vapor temperature at the outlet of said steam generator; eleventh means for establishing a reference value of the vapor temperature at the outlet of said steam generator; a first adder for obtaining the difference between the respective outputs of said tenth and eleventh means; a first adjuster for producing an output in accordance with the output of said first adder; twelfth means for establishing a reference value of the vapor temperature at the outlet of said evaporator; a second adder for obtaining the difference between the output of said twelfth means and the output of said evaporator outlet vapor temperature detector; a second adjuster for producing an output in accordance with the output of said second adder; and a third adder for obtaining the sum of the respective outputs of said first and second adders to thereby control the flow rate of the feed-water in absence of the output of said first means.
Claim 11
Dependent Claim
170 words
The improvement according to claim 4, in which said fifth means includes: tenth means for detecting the vapor temperature at the outlet of said steam generator; eleventh means for establishing a reference value of the vapor temperature at the outlet of said steam generator; a first adder for obtaining the difference between the respective outputs of said tenth and eleventh means; a first adjuster for producing an output in accordance with the output of said first adder; twelfth means for establishing a reference value of the vapor temperature at the outlet of said evaporator; a second adder for obtaining the difference between the output of said eleventh means and the output of said evaporator outlet vapor temperature detector; a second adjuster for producing an output in accordance with the output of said second adder; and a third adder for obtaining the sum of the respective outputs of said first and second adders to thereby control the flow rate of the feed-water in absence of the output of said first means.
References Cited (Backward Citations)
US3126053A
Cited
US3247069A
Cited
US3253994A
Cited
US3349003A
Cited
US3369971A
Cited
US3434924A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-26 | 1981-03-28 | 1981-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-26 | 1985-03-28 | 1985-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-26 | 1989-03-28 | 1989-09-27 | $7700.00 | Window Closed / Lapsed |