US4824740A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuel cell stack cooling system
Assignee: UTC Power Corp
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Filing: 1988-05-09
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Granted: 1989-04-25
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Expires: 2008-05-09
Abstract
Abstract Fuel Cell stack coolant water is processed by moving the two-phase water/steam coolant exhaust through a steam separator wherein the water phase is separated from the steam phase. The water phase is then moved through a heat exchanger where its temperature is lowered to a subcooled level which is below the coolant operating temperature in the stack. A flow control valve is associated with the coolant heat exchanger to regulate water flow through and/or around the heat exchanger depending on the temperature of the water which leaves the steam separator. By subcooling the coolant before it reenters the stack, a lessening of electrolyte loss through evaporation is achieved. By eliminating steam condensation as a form of system heat rejection, system engineering is simplified and construction costs are lowered.
Inventors
- 👤 Martin L. Abrams
- 👤 Daniel L. D'Aquila
- 👤 Glenn W. Scheffler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:52
CPC Classifications
H; H01; H01M; H01M8/00; H01M8/04; H01M8/04007; H01M8/04029; H01M8/04082; H01M8/04089; H01M8/04119; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
228 words
A fuel cell stack cooling using a water coolant comprising: (a) coolant passages in the stack, said coolant passages having an inlet end and an outlet end for receiving water and discharging a water/steam mixture respectively, said coolant passages in counterflow relationship to oxidation gas flowing through the stack; (b) a steam separator; (c) a first conduit at said coolant passage outlet end for conveying the water/steam mixture from said stack to said steam separator, wherein the water and steam are separated from each other; (d) a second conduit conveying steam from said steam separator to a catalytic fuel reformer; (e) a heat exchanger for removing heat from water passing therethrough; (f) a third conduit at said steam separator for conveying water from said steam separator to said heat exchanger operable to lower the temperature of the water; (g) a fourth conduit at said heat exchanger for conveying water from said heat exchanger to said inlet end of said coolant passages thereby forming a coolant loop; (h) a pump for circulating coolant through said loop; (i) modulating means for modulating the heat removed by said heat exchanger; (j) sensor means for sensing a measure of the temperature of the water in the steam separator; and (k) control means responsive to said sensor means for varying said modulation means to maintain said measure of temperature at a preselected value.
Claim 2
Dependent Claim
228 words
A fuel cell stack cooling using a water coolant comprising: (a) coolant passages in the stack, said coolant passages having an inlet end and an outlet end for receiving water and discharging a water/steam mixture respectively, said coolant passages in counterflow relationship to oxidation gas flowing through the stack; (b) a steam separator; (c) a first conduit at said coolant passage outlet end for conveying the water/steam mixture from said stack to said steam separator, wherein the water and steam are separated from each other; (d) a second conduit conveying steam from said steam separator to a catalytic fuel reformer; (e) a heat exchanger for removing heat from water passing therethrough; (f) a third conduit at said steam separator for conveying water from said steam separator to said heat exchanger operable to lower the temperature of the water; (g) a fourth conduit at said heat exchanger for conveying water from said heat exchanger to said inlet end of said coolant passages thereby forming a coolant loop; (h) a pump for circulating coolant through said loop; (i) modulating means for modulating the heat removed by said heat exchanger; (j) sensor means for sensing a measure of the temperature of the water in the steam separator; and (k) control means responsive to said sensor means for varying said modulation means to maintain said measure of temperature at a preselected value.
Claim 3
Dependent Claim
27 words
The cooling system of claim 1 further comprising a makeup water conduit for introducing makeup water into said third conduit between said sensor and said heat exchanger.
Claim 4
Dependent Claim
30 words
The cooling system of claim 2: said pump located in said third conduit, and said makeup water conduit connected to said third conduit between said steam separator and said pump.
Claim 5
Dependent Claim
37 words
The cooling system of claim 1: said sensor means for sensing a measure of the temperature of water in said separator comprising a temperature sensor located to sense the temperature of water flowing from said steam separator.
Claim 6
Dependent Claim
38 words
The cooling system of claim 1: said modulating means including a bypass conduit around said heat exchanger interconnecting said third and fourth conduits, and an adjustable valve to vary the proportion of water passing through said heat exchanger.
Claim 7
Dependent Claim
16 words
The cooling system of claim 5 wherein said adjustable valve means is a three way valve.
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) | 1992-04-24 | 1992-10-24 | 1993-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-24 | 1996-10-24 | 1997-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-24 | 2000-10-24 | 2001-04-25 | $7700.00 | Window Closed / Lapsed |