Patent US5503944A successfully refreshed from Google Patents.
US5503944A
Expired / Lapsed
US
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Water management system for solid polymer electrolyte fuel cell power plants
Assignee: Audi AG
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Filing: 1995-06-30
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Granted: 1996-04-02
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Expires: 2015-06-30
Abstract
Abstract A simplified solid polymer electrolyte fuel cell power plant utilizes porous conductive separator plates having central passages which are filled with circulating coolant water. The coolant water passes through a heat exchanger which rejects heat generated in the power plant. Water appearing on the cathode side of each cell membrane is pumped into the water circulation passages through the porous oxidant reactant flow field plates by a positive ΔP created between the cathode reactant flow field of each cell and the coolant water circulation passages between each cell. In order to create the desired ΔP, at least one of the reactant gas streams will be referenced to the coolant water loop so as to create a coolant loop pressure which is less than the referenced reactant gas stream pressure. Excess water is removed from the coolant water stream. The system can operate at ambient or at elevated pressures. Each cell in the power plant is individually cooled on demand, and the power plant does not require a separate cooling section or reactant stream humidifying devices.
Inventors
- 👤 Alfred P. Meyer
- 👤 Glenn W. Scheffler
- 👤 Paul R. Margiott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:59
CPC Classifications
H; H01; H01M; H01M8/00; H01M8/04; H01M8/04082; H01M8/04089; H01M8/04119; H01M8/04007; H01M8/04029; H01M2300/00; H01M2300/0017; H01M2300/0065; H01M2300/0082; H01M8/04291; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
154 words
A method for operating a solid polymer electrolyte fuel cell power plant having a membrane/electrode assembly (MEA)i said method comprising the steps of: a) providing oxidant and fuel reactant gas streams on opposite cathode and anode sides of the MEA; b) providing a circulating water stream on said cathode side of the MEA; c) providing a fine pore plate between said oxidant gas stream and said circulating water stream; d) pressurizing said oxidant reactant gas stream to a first pressure; e) imposing said first pressure from said oxidant reactant gas stream on said water stream; and f) partially counteracting said first pressure imposed on said water stream so as to create a positive target pressure differential (ΔP) between said oxidant reactant gas stream and said water stream, which ΔP is operative to pump product water formed on the cathode side of the MEA through said fine pore plate and into said circulating water stream.
Claim 2
Independent Claim
154 words
A method for operating a solid polymer electrolyte fuel cell power plant having a membrane/electrode assembly (MEA)i said method comprising the steps of: a) providing oxidant and fuel reactant gas streams on opposite cathode and anode sides of the MEA; b) providing a circulating water stream on said cathode side of the MEA; c) providing a fine pore plate between said oxidant gas stream and said circulating water stream; d) pressurizing said oxidant reactant gas stream to a first pressure; e) imposing said first pressure from said oxidant reactant gas stream on said water stream; and f) partially counteracting said first pressure imposed on said water stream so as to create a positive target pressure differential (ΔP) between said oxidant reactant gas stream and said water stream, which ΔP is operative to pump product water formed on the cathode side of the MEA through said fine pore plate and into said circulating water stream.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein said oxidant reactant gas stream is pressurized to a pressure which is above ambient pressure.
Claim 4
Dependent Claim
18 words
The method of claim 1 further comprising the step of periodically releasing product water from said water stream.
Claim 5
Dependent Claim
55 words
The method of claim 1 further comprising the step of providing a pressure regulating vessel which is divided by a pressure-transferring separator into respective oxidant gas stream and water stream chambers; and utilizing said separator to transfer the oxidant gas stream pressure from said oxidant gas stream chamber to water in said water stream chamber.
Claim 6
Dependent Claim
28 words
The method of claim 4 comprising the further step of applying a counteracting pressure to said separator from said water stream chamber so as to produce said ΔP.
Claim 7
Dependent Claim
17 words
The method of claim 1 wherein said water stream is also a coolant stream for an MEA.
Claim 8
Independent Claim
161 words
A method for operating a solid polymer electrolyte fuel cell power plant having a membrane/electrode assembly (MEA) at essentially ambient pressure, said method comprising the steps of: a) providing ambient air oxidant reactant and fuel gas reactant streams on respective opposite cathode and anode sides of the MEA; b) providing a circulating water stream on said cathode side of the MEA; c) providing a fine pore plate between said oxidant gas stream and said circulating water stream; d) providing an ambient surroundings-referenced pressure in said water stream by exposing a portion of said water stream to ambient surroundings; and e) pressurizing said ambient air reactant stream to a first pressure which is above ambient pressure so as to create a positive pressure (ΔP) differential between said ambient air reactant stream and said water stream, which ΔP is operative to pump product water formed on the cathode side of the MEA through said fine pore plate and into said circulating water stream.
Claim 9
Independent Claim
161 words
A method for operating a solid polymer electrolyte fuel cell power plant having a membrane/electrode assembly (MEA) at essentially ambient pressure, said method comprising the steps of: a) providing ambient air oxidant reactant and fuel gas reactant streams on respective opposite cathode and anode sides of the MEA; b) providing a circulating water stream on said cathode side of the MEA; c) providing a fine pore plate between said oxidant gas stream and said circulating water stream; d) providing an ambient surroundings-referenced pressure in said water stream by exposing a portion of said water stream to ambient surroundings; and e) pressurizing said ambient air reactant stream to a first pressure which is above ambient pressure so as to create a positive pressure (ΔP) differential between said ambient air reactant stream and said water stream, which ΔP is operative to pump product water formed on the cathode side of the MEA through said fine pore plate and into said circulating water stream.
Claim 10
Dependent Claim
23 words
The method of claim 7 wherein said ambient air reactant stream pressurizing step is performed with an air compressor or an air blower.
Claim 11
Dependent Claim
18 words
The method of claim 7 comprising the further step of periodically removing product water from said water stream.
Claim 12
Dependent Claim
29 words
The method of claim 9 further comprising the step of providing a coolant water stand pipe operable to receive and reference the water stream to extant ambient surroundings pressure.
Claim 13
Dependent Claim
23 words
The method of claim 10 wherein said product water-removing step is performed by releasing product water into ambient surroundings through said stand pipe.
Claim 14
Dependent Claim
14 words
The method of claim 7 wherein said water stream is a water coolant stream.
Claim 15
Dependent Claim
151 words
A solid polymer electrolyte fuel cell power plant having a membrane/electrode assembly (MEA), said power plant comprising: a) oxidant and fuel reactant gas streams on opposite cathode and anode sides of the MEA; b) a circulating water stream on said cathode side of the MEA; c) a fine pore plate between said oxidant gas stream and said circulating water stream; d) means for pressurizing said oxidant reactant gas stream to a first pressure; e) means for imposing said first pressure from said oxidant reactant gas stream on said water stream; and f) means for partially counteracting said first pressure imposed on said water stream so as to create a positive target pressure differential (ΔP) between said oxidant reactant gas stream and said water stream, which ΔP is operative to pump product water formed on the cathode side of the MEA through said fine pore plate and into said circulating water stream.
Claim 16
Dependent Claim
151 words
A solid polymer electrolyte fuel cell power plant having a membrane/electrode assembly (MEA), said power plant comprising: a) oxidant and fuel reactant gas streams on opposite cathode and anode sides of the MEA; b) a circulating water stream on said cathode side of the MEA; c) a fine pore plate between said oxidant gas stream and said circulating water stream; d) means for pressurizing said oxidant reactant gas stream to a first pressure; e) means for imposing said first pressure from said oxidant reactant gas stream on said water stream; and f) means for partially counteracting said first pressure imposed on said water stream so as to create a positive target pressure differential (ΔP) between said oxidant reactant gas stream and said water stream, which ΔP is operative to pump product water formed on the cathode side of the MEA through said fine pore plate and into said circulating water stream.
Claim 17
Dependent Claim
22 words
The assembly of claim 13 comprising means for pressurizing said oxidant reactant gas stream to a pressure which is above ambient pressure.
Claim 18
Dependent Claim
17 words
The assembly of claim 13 further comprising means for periodically releasing product water from said water stream.
Claim 19
Dependent Claim
52 words
The assembly of claim 13 further comprising a pressure regulating vessel which is divided by a pressure-transferring separator into respective oxidant gas stream and water stream chambers and which utilizes said separator to transfer the oxidant gas stream pressure from said oxidant gas stream chamber to water in said water stream chamber.
Claim 20
Dependent Claim
26 words
The assembly of claim 16 comprising means for applying a counteracting pressure to said separator from said water stream chamber so as to produce said ΔP.
Claim 21
Dependent Claim
17 words
The assembly of claim 13 wherein said water stream is also a coolant stream for the MEA.
Claim 22
Dependent Claim
169 words
A solid polymer electrolyte fuel cell power plant having a membrane/electrode assembly (MEA), said power plant comprising: a) ambient air oxidant reactant and fuel gas reactant flow fields on respective opposite cathode and anode sides of the MEA; b) a circulating water stream flow field On said cathode side of the MEA; c) a fine pore plate interposed between said oxidant reactant flow field and said circulating water stream flow field; d) means for providing an ambient surroundings-referenced pressure in said water stream flow field by exposing a portion of said water stream flow field to ambient surroundings; and e) means for pressurizing said ambient air reactant flow field to a first pressure which is above ambient pressure so as to create a positive pressure (ΔP) differential between said ambient air reactant flow field and said water stream flow field, which ΔP is operative to pump product water formed on the cathode side of the MEA through said fine pore plate and into said circulating water stream flow field.
Claim 23
Dependent Claim
169 words
A solid polymer electrolyte fuel cell power plant having a membrane/electrode assembly (MEA), said power plant comprising: a) ambient air oxidant reactant and fuel gas reactant flow fields on respective opposite cathode and anode sides of the MEA; b) a circulating water stream flow field On said cathode side of the MEA; c) a fine pore plate interposed between said oxidant reactant flow field and said circulating water stream flow field; d) means for providing an ambient surroundings-referenced pressure in said water stream flow field by exposing a portion of said water stream flow field to ambient surroundings; and e) means for pressurizing said ambient air reactant flow field to a first pressure which is above ambient pressure so as to create a positive pressure (ΔP) differential between said ambient air reactant flow field and said water stream flow field, which ΔP is operative to pump product water formed on the cathode side of the MEA through said fine pore plate and into said circulating water stream flow field.
Claim 24
Dependent Claim
18 words
The assembly of claim 19 wherein said means for pressurizing is an air compressor or an air blower.
Claim 25
Dependent Claim
19 words
The assembly of claim 19 further comprising means for periodically removing product water from said water stream flow field.
Claim 26
Dependent Claim
28 words
The assembly of claim 21 further comprising a water stand pipe open to ambient surroundings and operable to reference the water stream flow field to extant ambient pressure.
Claim 27
Dependent Claim
17 words
The assembly of claim 22 wherein said means for removing product water is in the stand pipe.
Claim 28
Dependent Claim
18 words
The assembly of claim 19 wherein said water stream flow field is also a coolant stream flow field.
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) | 1999-04-02 | 1999-10-02 | 2000-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-02 | 2003-10-02 | 2004-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-02 | 2007-10-02 | 2008-04-02 | $7700.00 | Window Closed / Lapsed |