US20100279190A1 - Cathode saturation arrangement for fuel cell power plant - Google Patents
Cathode saturation arrangement for fuel cell power plant Download PDFInfo
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- US20100279190A1 US20100279190A1 US12/803,640 US80364010A US2010279190A1 US 20100279190 A1 US20100279190 A1 US 20100279190A1 US 80364010 A US80364010 A US 80364010A US 2010279190 A1 US2010279190 A1 US 2010279190A1
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- coolant
- fuel cell
- temperature
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- cell stack
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04007—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids related to heat exchange
- H01M8/04029—Heat exchange using liquids
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
- H01M8/04089—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants
- H01M8/04119—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants with simultaneous supply or evacuation of electrolyte; Humidifying or dehumidifying
- H01M8/04126—Humidifying
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Definitions
- This invention relates to fuel cell power plants, and particularly to the management of heat in a fuel cell power plant. More particularly still, the invention relates to a fuel cell cathode saturation arrangement for managing heat loads in a fuel cell power plant designed for volume optimization.
- Fuel cell power plants are commonly used to produce electrical energy from reducing and oxidizing fluids to power electrical apparatus.
- one or typically a plurality, of planar fuel cells are arranged in a fuel cell stack, or cell stack assembly (CSA).
- Each cell generally includes an anode electrode and a cathode electrode separated by an electrolyte.
- a reducing fluid such as hydrogen is supplied to the anode electrode, and an oxidant such as oxygen or air is supplied to the cathode electrode.
- the reducing fluid and the oxidant are typically delivered to and removed from the cell stack via respective manifolds.
- the electrons are conducted to an external load circuit and then returned to the cathode electrode, while the hydrogen ions transfer through the electrolyte to the cathode electrode, where they react with the oxidant and electrons to produce water and release thermal energy.
- PEM proton exchange membrane
- the anode and cathode electrodes of such fuel cells are separated by different types of electrolytes, depending on operating requirements and limitations of the working environment of the fuel cell.
- One such electrolyte is a PEM electrolyte, which consists of a solid polymer well known in the art.
- Other common electrolytes used in fuel cells include phosphoric acid, sulfuric acid, or potassium hydroxide held within a porous, non-conductive matrix between the anode and cathode electrodes.
- PEM cells have substantial advantages over cells with liquid acid or alkaline electrolytes in satisfying specific operating parameters because the membrane of the PEM provides a barrier between the reducing fluid and oxidant that is more tolerant to pressure differentials, is fixed and cannot be leached from the cell, and has a relatively stable capacity for water retention.
- the coolant In addition to water balance in the fuel cell power plant, there is the further requirement of a coolant system for maintaining appropriate temperature of the various components of the power plant.
- the coolant will also be the water discussed above with respect to the need for water balance.
- the coolant is typically used to remove heat from certain portions of the fuel cell power plant, as for instance the fuel cell stack assembly (CSA), though the coolant may in some instances serve also as a source of heat.
- the coolant may also serve as a source of moisture for the control of humidification of various gas streams in the fuel cell power plant. In these ways the coolant serves to address the various heat loads of various portions of the fuel cell power plant.
- the CSA may include a coolant plate means, or the like, that defines a coolant channel through the cell stack assembly, typically adjacent to the cathode, and which forms part of a coolant loop that is both internal and external to the CSA.
- the coolant loop typically includes at least a circulation means, such as a pump, and some form of heat removal means, such as a radiator.
- the coolant serves the important role of removing heat from the CSA.
- Coolant entering the CSA adjacent to the exiting cathode exhaust serves to cool the exhaust stream and condense water out of that gas stream, through the use of fine pore media such as the coolant plate means that define the coolant channel adjacent the cathode exhaust.
- the amount of heat removed is a function of the coolant temperature and flow rate of the coolant entering the CSA.
- the heat removal means performs the important function of removing, prior to its reintroduction to the CSA, most of the heat acquired during the coolant's passage through the CSA. While the heat removal means might take a variety of forms, by far the most common is that of an air-cooled radiator. Typically, it is the task of the radiator to remove all of the heat acquired by the coolant's passage through the CSA.
- the air which cools the radiator is typically at some ambient temperature associated with the environment of the fuel cell power plant, and may typically be, or approach, 120° F. (49° C.), particularly if the CSA is being used in a hot environment such as a desert.
- the temperature of the coolant exiting the CSA is not substantially greater than that of the radiator-cooling air, or stated conversely, because the temperature of the radiator-cooling air may be only a little less than that of the coolant exiting the CSA, the resulting relatively small temperature differential, sometimes referred to as the “pinch”, requires that the capacity of the radiator be relatively large in order to achieve the necessary cooling. On the other hand, this relative largeness of the radiator may be objectionable for several reasons, including initial cost, weight, size, appearance, and costs associated with its operation and maintenance.
- the heat and/or heat loads of various devices or portions of a fuel cell power plant are redistributed or re-allocated in a manner allowing desired modification of/to the heat removal means included in the coolant loop for the fuel cell stack assembly (CSA).
- CSA fuel cell stack assembly
- the addition of a humidifier in the coolant loop and the inlet oxidant (air) stream serves to relatively increase the humidification of the inlet air while removing heat from the coolant prior to entering the CSA.
- the combined effects are to relatively increase the temperature of the coolant exiting the CSA without similarly increasing the temperature of the coolant entering the CSA, and further to relatively increase the temperature differential (“pinch”) between the coolant entering the heat removal means and the cooling air of the heat removal means. This latter effect permits a relative reduction in the size/capacity of the heat removal means required.
- a fuel cell stack assembly (CSA), a coolant loop including a heat removal means, operatively associated with the CSA, and a humidifier operatively connected in the coolant loop.
- the CSA includes an anode region having an inlet and an outlet, a cathode region having an inlet and an outlet, an electrolyte region intermediate the anode and cathode regions, and a coolant region having an inlet and an outlet connected in the coolant loop.
- An inlet fuel stream is connected to the anode region inlet.
- An inlet oxidant stream is operatively connected to the cathode region inlet via the humidifier.
- the heat removal means may typically be a radiator, actively cooled by a medium such as air having a temperature somewhat less than that of the coolant from the CSA.
- the inlet oxidant stream is passed through the humidifier before entering the cathode of the CSA, and in the humidifier becomes at least partially, and typically heavily, humidified by mass and heat transfer association with the coolant also being passed through the humidifier.
- the humidifier needs to allow mass and heat transfer between two fluid streams, as via an energy recovery device (ERD).
- the ERD may preferably be of the type in which a fine pore medium separates the two streams but allows fluid transfer therebetween, or alternatively may be a bubble or contact saturator or the like in which there is direct contact between the two fluid streams without the presence of an intermediate porous barrier.
- FIG. 1 is a simplified schematic diagram of a fuel cell power plant in accordance with the prior art, illustrating examples of temperatures at selected portions of the plant including the fuel cell stack assembly (CSA) and the coolant loop;
- CSA fuel cell stack assembly
- FIG. 2 is a simplified graphic view of the evaporation/condensation profile in a standard fuel cell for an air stream that is not highly humidified;
- FIG. 3 is a simplified graphic view of the evaporation/condensation profile in a standard fuel cell for an air stream that is highly humidified
- FIG. 4 is a simplified schematic diagram similar to FIG. 1 , of a fuel cell power plant in accordance with the invention, illustrating the inclusion of a humidifier for humidifying the inlet oxidant and further cooling the coolant, and illustrating examples of temperatures at selected portions of the plant.
- FIG. 1 there is depicted in simplified schematic diagram form a fuel cell power plant 10 in accordance with the prior art, indicating representative temperatures at selected portions of the plant, including a fuel cell stack assembly (CSA) 12 and a coolant loop 14 .
- the fuel cell power plant 10 includes a number of fuel cells arranged in a known manner in a fuel cell stack assembly 12 .
- CSA 12 in FIG. 1 is intended to embrace plural fuel cells, it is depicted as a single cell for ease of illustration and reference.
- Each fuel cell typically includes an anode region 16 , a cathode region 18 , an electrolyte region 20 between the anode region 16 and the cathode region 18 , and a coolant region or coolant channel 22 , typically adjacent the cathode region 18 .
- the electrolyte is preferably a proton exchange membrane (PEM) type employing a solid polymer well known in the art.
- a reducing agent in the form of a hydrogen-rich fuel stream 24 is supplied to the anode region 16 , as at anode inlet 26 .
- the various anode, cathode, and coolant region inlets and outlets mentioned hereinafter are typically in the form of manifolds serving the respective regions.
- the hydrogen-rich fuel stream 24 is typically derived from a hydrocarbon fuel source 28 by means of a fuel processing system (FPS) 30 of known design.
- a source of oxidant 32 such as air, supplies an oxidant stream 34 to the cathode region 18 via cathode inlet 36 , which flow may be assisted in a known manner by a motive device, such as a fan, compressor, or blower 38 .
- partially-depleted fuel is discharged or exhausted as anode exhaust stream 40 at anode outlet 42 .
- partially-depleted oxidant is exhausted as cathode exhaust stream 44 at cathode outlet 46 .
- the coolant channel 22 is an included portion of the coolant loop 14 , and may be defined by a sealed or a porous coolant plate, not separately shown.
- the coolant typically water
- the coolant channel 22 may not flow between the coolant channel 22 and the cathode and/or anode regions 18 , 16 .
- the coolant water and product water may pass between the coolant channel 22 and the cathode and/or anode regions 18 , 16 via the pores. In either event, water in the coolant loop 14 enters the coolant channel 22 of CSA 12 at inlet 48 and returns to the loop via outlet 50 .
- the coolant loop 14 is here shown in simplified form as containing a heat removal means, such as radiator 52 , and a circulation-assistance means, such as pump 54 .
- a coolant loop portion 14 ′ connects coolant channel outlet 50 with pump 54
- a portion 14 ′′ connects pump 54 with the inlet to radiator 52
- a further portion 14 ′′′ connects the outlet of radiator 52 to the coolant channel inlet 48 .
- the radiator 52 includes a motorized fan 56 for forcing air through, or across, the radiator to effect heat transfer between that air and the liquid coolant passing through the radiator and the coolant loop 14 .
- the coolant loop 14 may additionally include a variety of means, not shown, for cleansing, degasifying, adding and/or discharging, and/or otherwise processing the coolant, as is known in the art.
- the radiator 52 may need to be relatively large to provide the amount of cooling needed to remove heat acquired during the coolant's passage through the CSA 12 .
- the function of the coolant as it passes through the CSA 12 is to remove heat generated by the fuel cell reaction.
- radiator 52 The sizing of radiator 52 is primarily governed by the difference in temperature between the coolant exiting the CSA 12 on coolant loop portions 14 ′, and 14 ′′ and thus entering the radiator, and the air being delivered by fan 56 to remove heat from the coolant in the radiator.
- the coolant outlet 50 of CSA 12 may be viewed as the “Source” of heat and the air-cooled radiator 52 as the “Sink”.
- Source temperature and sink temperature the difference between these two temperatures (source temperature and sink temperature) gets smaller, or closer, the radiator size and fan power requirements get larger, and in a non-linear manner, such that a small decrease in that temperature differential may result in a relatively much larger change (increase) in the size of the radiator 52 .
- both the air (oxidant) stream 34 entering the cathode 18 and the air at fan 56 being used to cool radiator are at 120° F. (49° C.).
- the coolant entering coolant channel 22 at coolant inlet 48 has a temperature of about 135° F. (57° C.)
- the temperature of the coolant exiting the coolant channel 22 at outlet 50 will have a temperature of about 160° F. (71° C.).
- Source temperature-to-Sink temperature difference of only 40° F. (22° C.), thereby requiring a relatively large radiator and fan.
- the coolant enters the CSA 12 at coolant inlet 48 , which is along the edge, or in the area, where the cathode air exits, as at cathode outlet 46 .
- the coolant serves to cool the cathode exhaust stream there and condense water out of the cathode exhaust. That condensed water is represented quantitatively and locationally by the dense hatching 58 .
- the heat is removed from the cathode gas stream and enters the coolant. The amount of heat removed is a function of the coolant inlet 48 temperature and flow rate to the CSA. For the same flow rate, a reduction in coolant temperature results in more water being condensed.
- sufficient water is condensed to maintain water balance in the power plant 10 , including the FPS 30 and the coolant loop 14 , if the coolant flow is sufficient, for example 45 pph/cell, and the coolant temperature is low enough, for example 135° F. (57° C.).
- the coolant inlet 48 meets the aforementioned conditions, then the power plant shall be in water balance.
- the coolant exits the CSA 12 at coolant outlet 50 , which is along the edge, or in the area, where the air enters the cathode 18 , as at cathode inlet 36 .
- the heated coolant water serves to heat and, to some extent, humidify this cathode air stream because the CSA 12 in this respect operates in a manner analogous to an energy recovery device. That humidification occurs in an evaporation region of the fuel cell that is represented quantitatively and locationally by the simple hatching 60 . In this evaporation region 60 , the heat is removed from the coolant and enters the cathode gas stream.
- the temperature of the coolant correspondingly drops such that, in the aforementioned representative example, the coolant temperature at the coolant outlet is about 160° F. (71° C.). These temperatures are consistent with those depicted in the system of FIG. 1 .
- FIG. 3 is similar in most respects to FIG. 2 , but in which the air stream entering the cathode 18 at cathode inlet 36 has already been humidified to a dew point approximate to the inlet temperature of the CSA 12 , such that relatively less heat and water is required to complete the humidification to local operating conditions of the CSA 12 .
- This difference is depicted by the evaporation region 60 in FIG. 3 being relatively smaller than it was in FIG. 2 , and results in a higher-grade (temperature) heat exiting the fuel cell (or CSA 16 ) in the coolant at coolant outlet 50 .
- the dew point of the air stream entering the cathode inlet 36 were now 130° F. (54.5° C.) as a result of its increased humidification prior to that point, the coolant temperature at coolant exit 50 would increase to about 165° F. (74° C.).
- FIG. 4 there is depicted a fuel cell power plant 110 in accordance with the invention.
- Reference numbers identical to those of FIG. 1 are used in FIG. 4 for those components that are the same, or substantially the same, in the two configurations.
- the components of FIG. 4 nevertheless remain analogous to components in FIG. 1 , they have been given the same reference number, but preceded by a “1”.
- the following description will emphasize the novel character, structure, and/or function of the contaminant removal system of the invention, and will attempt to minimize repetition of description that is duplicative of that provided with respect to FIG. 1 .
- the humidifying device 70 is a relatively simple, small, and inexpensive device, and may typically take the form of an energy recovery device (ERD) having a gas flow chamber 72 and a liquid, or coolant, flow chamber 74 separated by an enthalpy exchange barrier 76 therebetween.
- ERP energy recovery device
- the humidifying device 70 may be of any generally known construction in which an oxidant (air) stream and a coolant (water) stream may be passed in relative heat and mass transfer relation for relatively increasing the dew point/humidity of the air entering the cathode 18 of CSA 12 while also removing heat from the coolant to be entering the coolant channel 22 of the CSA. It is preferred that the ERD 70 be sufficiently compact, simple and inexpensive to offset those aspects of the prior radiator 52 and/or motorized fan 56 relative to the radiator 152 and/or motorized fan 156 replacing them.
- a preferred ERD 70 is of the type having adjacent gas and liquid chambers, 72 and 74 respectively, separated by a fine pore saturator medium, typically of graphite of the like, forming the enthalpy exchange barrier 76 .
- a fine pore saturator medium typically of graphite of the like, forming the enthalpy exchange barrier 76 .
- Other acceptable barriers may be of the type similar to the fine pore, water transfer plates such as used in/for the coolant channels within the CSA 12 .
- An alternative form of humidifier or energy recovery device, 70 may be a bubble or contact saturator (not separately shown) in which the oxidant (air) stream is brought directly into contact with the coolant (water), as in a tank, reservoir, conduit, or the like, to effect the requisite transfer of mass and energy between the two fluids without requiring that transfer to occur indirectly via an intermediate enthalpy exchange barrier.
- the humidifying device 70 is inserted into the coolant loop 114 relatively downstream of the radiator 152 and relatively upstream of the coolant inlet 48 to the coolant channel 22 in CSA 12 . Similarly, the humidifying device 70 is in the inlet oxidant stream between the oxidant source 32 and the cathode inlet 36 to the cathode 18 of CSA 12 .
- a coolant loop portion 114 ′′′ connects the outlet, or discharge end, of radiator 152 to the inlet end of coolant flow chamber 74 of ERD 70
- a coolant loop portion 114 ′′′′ connects the outlet end of that coolant flow chamber to the coolant inlet 48 of CSA 12 .
- An oxidant conduit portion 134 connects oxidant from blower 38 to the inlet end of the gas flow chamber 72 of ERD 70 , and a further oxidant conduit portion 134 ′ connects the outlet end of that gas flow chamber to the cathode inlet 36 of CSA 12 .
- the blower 38 may be located either prior to the inlet or after the outlet, of gas flow chamber 72 . It is generally desirable for the air in gas flow chamber 72 and the water in coolant flow chamber 74 to flow in counter flow relation to one another for maximum efficiency of the ERD, though other configurations are within the scope of the invention.
- radiator 152 This enables the radiator 152 to effect the same amount of cooling, i.e., a drop of about 25° F. (14° C.) to 140° F. (60° C.) at its outlet on loop portion 114 ′′′, with a radiator of relatively smaller capacity than that required for the same temperature drop across the radiator 52 of FIG. 1 . This is accomplished because even though the temperature of the coolant leaving radiator 152 is 5° F. (3° C.) higher than the 135° F.
- the fuel cell power plant 110 may be operated as satisfactorily as was the power plant 10 , yet with a relatively smaller and simpler radiator 152 /motorized fan 156 than was the case in power plant 10 , and at an additional “cost” of only a relatively simple, compact, and inexpensive ERD/humidifier 70 .
- the reduced size and cost of the radiator 152 /fan 156 is typically a net advantage over any increased cost and size of the added humidifier 70 .
- the radiator 52 of the heat removal means may be any of numerous types of heat exchangers, e.g., liquid to liquid, liquid to gas, etc.
- the humidifying device 70 may take various forms, including the fine pore saturator medium of an ERD, the water transfer plates as in a CSA, a bubble saturator, or the like, as well as others.
Abstract
The heat from various portions of a fuel cell power plant (110) are redistributed in a manner allowing desired modification of/to the heat removal means (152,156), e.g., radiator (152), included in the coolant loop for the fuel cell stack assembly (CSA) (12). A humidifier (70) added in the coolant loop (114) and the inlet oxidant (air) stream (134′) serves to relatively increase the humidification of the inlet air while removing heat from the coolant prior to entering the CSA (12). The combined effects are to relatively increase the temperature of the coolant exiting the CSA without similarly increasing the temperature of the coolant entering the CSA, and to relatively increase the temperature differential (“pinch”) between the coolant entering the heat removal means and the cooling air of the heat removal means (152, 156). This latter effect permits a relative reduction in the size/capacity of the heat removal means (152, 156).
Description
- This application is a continuation of U.S. patent application Ser. No. 11,787,570 filed Apr. 17, 2007, which in turn is a continuation of U.S. patent application Ser. No. 11/327,912 filed Jan. 9, 2006, which is in turn a divisional of U.S. patent application Ser. No. 10/723,081 filed Nov. 26, 2003, now U.S. Pat. No. 7,014,933.
- This invention relates to fuel cell power plants, and particularly to the management of heat in a fuel cell power plant. More particularly still, the invention relates to a fuel cell cathode saturation arrangement for managing heat loads in a fuel cell power plant designed for volume optimization.
- Fuel cell power plants are commonly used to produce electrical energy from reducing and oxidizing fluids to power electrical apparatus. In such power plants, one or typically a plurality, of planar fuel cells are arranged in a fuel cell stack, or cell stack assembly (CSA). Each cell generally includes an anode electrode and a cathode electrode separated by an electrolyte. A reducing fluid such as hydrogen is supplied to the anode electrode, and an oxidant such as oxygen or air is supplied to the cathode electrode. The reducing fluid and the oxidant are typically delivered to and removed from the cell stack via respective manifolds. In a cell using a proton exchange membrane (PEM) as the electrolyte, the hydrogen electrochemically reacts at a catalyst surface of the anode electrode to produce hydrogen ions and electrons. The electrons are conducted to an external load circuit and then returned to the cathode electrode, while the hydrogen ions transfer through the electrolyte to the cathode electrode, where they react with the oxidant and electrons to produce water and release thermal energy.
- The anode and cathode electrodes of such fuel cells are separated by different types of electrolytes, depending on operating requirements and limitations of the working environment of the fuel cell. One such electrolyte is a PEM electrolyte, which consists of a solid polymer well known in the art. Other common electrolytes used in fuel cells include phosphoric acid, sulfuric acid, or potassium hydroxide held within a porous, non-conductive matrix between the anode and cathode electrodes. It has been found that PEM cells have substantial advantages over cells with liquid acid or alkaline electrolytes in satisfying specific operating parameters because the membrane of the PEM provides a barrier between the reducing fluid and oxidant that is more tolerant to pressure differentials, is fixed and cannot be leached from the cell, and has a relatively stable capacity for water retention.
- In operation of PEM fuel cells, it is usually desirable that a proper water balance be maintained between the rate at which water is produced at the cathode electrode including water resulting from proton drag through the PEM electrolyte and the rate at which water is removed from the cathode and anode electrodes. This is to prevent excessive drying or flooding of one or more of the various elements of the fuel cell.
- In addition to water balance in the fuel cell power plant, there is the further requirement of a coolant system for maintaining appropriate temperature of the various components of the power plant. Typically, though not necessarily, the coolant will also be the water discussed above with respect to the need for water balance. The coolant is typically used to remove heat from certain portions of the fuel cell power plant, as for instance the fuel cell stack assembly (CSA), though the coolant may in some instances serve also as a source of heat. The coolant may also serve as a source of moisture for the control of humidification of various gas streams in the fuel cell power plant. In these ways the coolant serves to address the various heat loads of various portions of the fuel cell power plant.
- The CSA may include a coolant plate means, or the like, that defines a coolant channel through the cell stack assembly, typically adjacent to the cathode, and which forms part of a coolant loop that is both internal and external to the CSA. The coolant loop typically includes at least a circulation means, such as a pump, and some form of heat removal means, such as a radiator. Inasmuch as the electrochemical reaction in the CSA may be the source of considerable heat, the coolant serves the important role of removing heat from the CSA. Coolant entering the CSA adjacent to the exiting cathode exhaust serves to cool the exhaust stream and condense water out of that gas stream, through the use of fine pore media such as the coolant plate means that define the coolant channel adjacent the cathode exhaust. The amount of heat removed is a function of the coolant temperature and flow rate of the coolant entering the CSA.
- Because the coolant is recirculated in the coolant loop, the heat removal means performs the important function of removing, prior to its reintroduction to the CSA, most of the heat acquired during the coolant's passage through the CSA. While the heat removal means might take a variety of forms, by far the most common is that of an air-cooled radiator. Typically, it is the task of the radiator to remove all of the heat acquired by the coolant's passage through the CSA. The air which cools the radiator is typically at some ambient temperature associated with the environment of the fuel cell power plant, and may typically be, or approach, 120° F. (49° C.), particularly if the CSA is being used in a hot environment such as a desert. Because the temperature of the coolant exiting the CSA is not substantially greater than that of the radiator-cooling air, or stated conversely, because the temperature of the radiator-cooling air may be only a little less than that of the coolant exiting the CSA, the resulting relatively small temperature differential, sometimes referred to as the “pinch”, requires that the capacity of the radiator be relatively large in order to achieve the necessary cooling. On the other hand, this relative largeness of the radiator may be objectionable for several reasons, including initial cost, weight, size, appearance, and costs associated with its operation and maintenance.
- Thus it is desirable to provide a fuel cell power plant in which the heat is managed in a manner allowing for a relative reduction in the sizing of the heat removal means, such as a radiator.
- The heat and/or heat loads of various devices or portions of a fuel cell power plant are redistributed or re-allocated in a manner allowing desired modification of/to the heat removal means included in the coolant loop for the fuel cell stack assembly (CSA). The addition of a humidifier in the coolant loop and the inlet oxidant (air) stream serves to relatively increase the humidification of the inlet air while removing heat from the coolant prior to entering the CSA. The combined effects are to relatively increase the temperature of the coolant exiting the CSA without similarly increasing the temperature of the coolant entering the CSA, and further to relatively increase the temperature differential (“pinch”) between the coolant entering the heat removal means and the cooling air of the heat removal means. This latter effect permits a relative reduction in the size/capacity of the heat removal means required.
- In a fuel cell power plant, there is provided a fuel cell stack assembly (CSA), a coolant loop including a heat removal means, operatively associated with the CSA, and a humidifier operatively connected in the coolant loop. The CSA includes an anode region having an inlet and an outlet, a cathode region having an inlet and an outlet, an electrolyte region intermediate the anode and cathode regions, and a coolant region having an inlet and an outlet connected in the coolant loop. An inlet fuel stream is connected to the anode region inlet. An inlet oxidant stream is operatively connected to the cathode region inlet via the humidifier. The heat removal means may typically be a radiator, actively cooled by a medium such as air having a temperature somewhat less than that of the coolant from the CSA. The inlet oxidant stream is passed through the humidifier before entering the cathode of the CSA, and in the humidifier becomes at least partially, and typically heavily, humidified by mass and heat transfer association with the coolant also being passed through the humidifier. The humidifier needs to allow mass and heat transfer between two fluid streams, as via an energy recovery device (ERD). The ERD may preferably be of the type in which a fine pore medium separates the two streams but allows fluid transfer therebetween, or alternatively may be a bubble or contact saturator or the like in which there is direct contact between the two fluid streams without the presence of an intermediate porous barrier.
- The foregoing features and advantages of the present invention will become more apparent in light of the following detailed description of exemplary embodiments thereof as illustrated in the accompanying drawings.
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FIG. 1 is a simplified schematic diagram of a fuel cell power plant in accordance with the prior art, illustrating examples of temperatures at selected portions of the plant including the fuel cell stack assembly (CSA) and the coolant loop; -
FIG. 2 is a simplified graphic view of the evaporation/condensation profile in a standard fuel cell for an air stream that is not highly humidified; -
FIG. 3 is a simplified graphic view of the evaporation/condensation profile in a standard fuel cell for an air stream that is highly humidified; and -
FIG. 4 is a simplified schematic diagram similar toFIG. 1 , of a fuel cell power plant in accordance with the invention, illustrating the inclusion of a humidifier for humidifying the inlet oxidant and further cooling the coolant, and illustrating examples of temperatures at selected portions of the plant. - Referring to
FIG. 1 , there is depicted in simplified schematic diagram form a fuelcell power plant 10 in accordance with the prior art, indicating representative temperatures at selected portions of the plant, including a fuel cell stack assembly (CSA) 12 and acoolant loop 14. The fuelcell power plant 10 includes a number of fuel cells arranged in a known manner in a fuelcell stack assembly 12. Although the illustration ofCSA 12 inFIG. 1 is intended to embrace plural fuel cells, it is depicted as a single cell for ease of illustration and reference. Each fuel cell, and thus theCSA 12, typically includes ananode region 16, acathode region 18, anelectrolyte region 20 between theanode region 16 and thecathode region 18, and a coolant region orcoolant channel 22, typically adjacent thecathode region 18. The electrolyte is preferably a proton exchange membrane (PEM) type employing a solid polymer well known in the art. - In the fuel
cell power plant 10, a reducing agent in the form of a hydrogen-rich fuel stream 24 is supplied to theanode region 16, as atanode inlet 26. The various anode, cathode, and coolant region inlets and outlets mentioned hereinafter are typically in the form of manifolds serving the respective regions. The hydrogen-rich fuel stream 24 is typically derived from ahydrocarbon fuel source 28 by means of a fuel processing system (FPS) 30 of known design. A source ofoxidant 32, such as air, supplies anoxidant stream 34 to thecathode region 18 viacathode inlet 36, which flow may be assisted in a known manner by a motive device, such as a fan, compressor, orblower 38. - After passing through the
anode region 16, partially-depleted fuel is discharged or exhausted asanode exhaust stream 40 atanode outlet 42. After passing through thecathode region 18, partially-depleted oxidant is exhausted ascathode exhaust stream 44 atcathode outlet 46. - The
coolant channel 22 is an included portion of thecoolant loop 14, and may be defined by a sealed or a porous coolant plate, not separately shown. When characterized as a sealed plate, the coolant, typically water, may not flow between thecoolant channel 22 and the cathode and/oranode regions coolant channel 22 and the cathode and/oranode regions coolant loop 14 enters thecoolant channel 22 ofCSA 12 atinlet 48 and returns to the loop viaoutlet 50. Thecoolant loop 14 is here shown in simplified form as containing a heat removal means, such asradiator 52, and a circulation-assistance means, such aspump 54. Acoolant loop portion 14′ connectscoolant channel outlet 50 withpump 54, aportion 14″ connectspump 54 with the inlet toradiator 52, and afurther portion 14′″ connects the outlet ofradiator 52 to thecoolant channel inlet 48. Theradiator 52 includes amotorized fan 56 for forcing air through, or across, the radiator to effect heat transfer between that air and the liquid coolant passing through the radiator and thecoolant loop 14. Thecoolant loop 14 may additionally include a variety of means, not shown, for cleansing, degasifying, adding and/or discharging, and/or otherwise processing the coolant, as is known in the art. - In the conventional power plant configuration depicted in
FIG. 1 , theradiator 52 may need to be relatively large to provide the amount of cooling needed to remove heat acquired during the coolant's passage through theCSA 12. The function of the coolant as it passes through theCSA 12 is to remove heat generated by the fuel cell reaction. - The sizing of
radiator 52 is primarily governed by the difference in temperature between the coolant exiting theCSA 12 oncoolant loop portions 14′, and 14″ and thus entering the radiator, and the air being delivered byfan 56 to remove heat from the coolant in the radiator. In this consideration, thecoolant outlet 50 ofCSA 12 may be viewed as the “Source” of heat and the air-cooledradiator 52 as the “Sink”. As the difference between these two temperatures (source temperature and sink temperature) gets smaller, or closer, the radiator size and fan power requirements get larger, and in a non-linear manner, such that a small decrease in that temperature differential may result in a relatively much larger change (increase) in the size of theradiator 52. Conversely, a small increase in that temperature differential may enable a significant decrease in the size of theradiator 52, other things being relatively constant. This result is accomplished by adjusting the operating points, and thus the energy concentration, or temperature, at various points in the system. Reference will be made to initial operating conditions and temperatures inFIG. 1 as being representative of the prior art. It should be understood that the temperatures mentioned herein with respect toFIGS. 1-4 are meant to be arbitrary and merely exemplary and in no way limiting, and are cited principally for illustrative comparative purposes. If it is assumed the ambient air at, or in, the fuelcell power plant 10 is about 120° F. (49° C.), as in a worst case operating condition, then it will be seen that both the air (oxidant)stream 34 entering thecathode 18 and the air atfan 56 being used to cool radiator are at 120° F. (49° C.). For this explanation ofFIG. 1 , assume that the coolant enteringcoolant channel 22 atcoolant inlet 48 has a temperature of about 135° F. (57° C.), and the temperature of the coolant exiting thecoolant channel 22 atoutlet 50 will have a temperature of about 160° F. (71° C.). Thus, it is necessary to obtain a 25° F. (14° C.) coolant temperature drop across theradiator 52 with Source temperature-to-Sink temperature difference of only 40° F. (22° C.), thereby requiring a relatively large radiator and fan. - At this juncture it is useful to consider the evaporation/condensation profiles of a typical fuel cell in which, first, the cathode air stream is not highly humidified, as seen in
FIG. 2 , and secondly, the cathode air stream is highly, or at least relatively more highly, humidified, or saturated, as seen inFIG. 3 . It should be understood when referring toFIGS. 2 and 3 that some graphic license is used in depicting the interior of a fuel cell, especially the cathode air stream and the coolant flow path, and although the orientations are dissimilar fromFIG. 1 , the appropriate reference numerals have been used. - Referring first to
FIG. 2 , the coolant enters theCSA 12 atcoolant inlet 48, which is along the edge, or in the area, where the cathode air exits, as atcathode outlet 46. The coolant serves to cool the cathode exhaust stream there and condense water out of the cathode exhaust. That condensed water is represented quantitatively and locationally by thedense hatching 58. Correspondingly, the heat is removed from the cathode gas stream and enters the coolant. The amount of heat removed is a function of thecoolant inlet 48 temperature and flow rate to the CSA. For the same flow rate, a reduction in coolant temperature results in more water being condensed. In a representative fuel cell power plant, sufficient water is condensed to maintain water balance in thepower plant 10, including theFPS 30 and thecoolant loop 14, if the coolant flow is sufficient, for example 45 pph/cell, and the coolant temperature is low enough, for example 135° F. (57° C.). Thus, regardless of activity in the remainder of thecoolant loop 14 ofFIG. 1 , if thecoolant inlet 48 meets the aforementioned conditions, then the power plant shall be in water balance. - Referring further to
FIG. 2 , the coolant exits theCSA 12 atcoolant outlet 50, which is along the edge, or in the area, where the air enters thecathode 18, as atcathode inlet 36. The heated coolant water serves to heat and, to some extent, humidify this cathode air stream because theCSA 12 in this respect operates in a manner analogous to an energy recovery device. That humidification occurs in an evaporation region of the fuel cell that is represented quantitatively and locationally by thesimple hatching 60. In thisevaporation region 60, the heat is removed from the coolant and enters the cathode gas stream. The temperature of the coolant correspondingly drops such that, in the aforementioned representative example, the coolant temperature at the coolant outlet is about 160° F. (71° C.). These temperatures are consistent with those depicted in the system ofFIG. 1 . - Reference is now made to
FIG. 3 , which is similar in most respects toFIG. 2 , but in which the air stream entering thecathode 18 atcathode inlet 36 has already been humidified to a dew point approximate to the inlet temperature of theCSA 12, such that relatively less heat and water is required to complete the humidification to local operating conditions of theCSA 12. This difference is depicted by theevaporation region 60 inFIG. 3 being relatively smaller than it was inFIG. 2 , and results in a higher-grade (temperature) heat exiting the fuel cell (or CSA 16) in the coolant atcoolant outlet 50. For the example mentioned above, if the dew point of the air stream entering thecathode inlet 36 were now 130° F. (54.5° C.) as a result of its increased humidification prior to that point, the coolant temperature atcoolant exit 50 would increase to about 165° F. (74° C.). - Simply raising the temperature of the coolant exiting the fuel cell/
CSA 12 atcoolant outlet 50 does not, in and of itself, accomplish the objective of being able to reduce the radiator size. This is principally because it would also relatively raise the temperature of the coolant enteringcoolant inlet 48, which runs counter to the discussion above which required that temperature to remain at about 135° F. (57° C.). However, the process of partially humidifying the air stream for delivery to thecathode inlet 36 overcomes that obstacle. Based on the example discussed-above, by humidifying the air stream to a dew point of 135° F. (57° C.), there results the transfer of heat equivalent to the removal of more than 5° F. (3″ C) from the coolant. This is attained by the addition of a humidifying device in accordance with the invention. - Referring to
FIG. 4 , there is depicted a fuelcell power plant 110 in accordance with the invention. Reference numbers identical to those ofFIG. 1 are used inFIG. 4 for those components that are the same, or substantially the same, in the two configurations. However, where there is some functional, compositional, or structural difference occasioned by the invention, but the components ofFIG. 4 nevertheless remain analogous to components inFIG. 1 , they have been given the same reference number, but preceded by a “1”. The following description will emphasize the novel character, structure, and/or function of the contaminant removal system of the invention, and will attempt to minimize repetition of description that is duplicative of that provided with respect toFIG. 1 . - While the fuel
cell power plant 110 ofFIG. 4 is similar in most respects to thepower plant 10 described with respect toFIG. 1 , it differs in at least the important aspect that the addition of ahumidifying device 70 enables the use of relatively smaller, simpler heat removal devices, in the form of a relativelysmaller radiator 152 andmotorized fan 156. Thehumidifying device 70 is a relatively simple, small, and inexpensive device, and may typically take the form of an energy recovery device (ERD) having agas flow chamber 72 and a liquid, or coolant, flowchamber 74 separated by anenthalpy exchange barrier 76 therebetween. Thehumidifying device 70, hereinafter also referred to as “ERD 70”, may be of any generally known construction in which an oxidant (air) stream and a coolant (water) stream may be passed in relative heat and mass transfer relation for relatively increasing the dew point/humidity of the air entering thecathode 18 ofCSA 12 while also removing heat from the coolant to be entering thecoolant channel 22 of the CSA. It is preferred that theERD 70 be sufficiently compact, simple and inexpensive to offset those aspects of theprior radiator 52 and/ormotorized fan 56 relative to theradiator 152 and/ormotorized fan 156 replacing them. Apreferred ERD 70 is of the type having adjacent gas and liquid chambers, 72 and 74 respectively, separated by a fine pore saturator medium, typically of graphite of the like, forming theenthalpy exchange barrier 76. A detailed description of one such arrangement may be found in U.S. Pat. No. 6,274,259 to Grasso, et al and assigned to the assignee of the present invention, though the present invention may not require the inclusion of that patent's transfer medium loop for wetting theenthalpy exchange barrier 76 herein. Other acceptable barriers may be of the type similar to the fine pore, water transfer plates such as used in/for the coolant channels within theCSA 12. An alternative form of humidifier or energy recovery device, 70, may be a bubble or contact saturator (not separately shown) in which the oxidant (air) stream is brought directly into contact with the coolant (water), as in a tank, reservoir, conduit, or the like, to effect the requisite transfer of mass and energy between the two fluids without requiring that transfer to occur indirectly via an intermediate enthalpy exchange barrier. - The
humidifying device 70 is inserted into thecoolant loop 114 relatively downstream of theradiator 152 and relatively upstream of thecoolant inlet 48 to thecoolant channel 22 inCSA 12. Similarly, thehumidifying device 70 is in the inlet oxidant stream between theoxidant source 32 and thecathode inlet 36 to thecathode 18 ofCSA 12. Acoolant loop portion 114′″ connects the outlet, or discharge end, ofradiator 152 to the inlet end ofcoolant flow chamber 74 ofERD 70, and acoolant loop portion 114″″ connects the outlet end of that coolant flow chamber to thecoolant inlet 48 ofCSA 12. Anoxidant conduit portion 134 connects oxidant fromblower 38 to the inlet end of thegas flow chamber 72 ofERD 70, and a furtheroxidant conduit portion 134′ connects the outlet end of that gas flow chamber to thecathode inlet 36 ofCSA 12. It will be understood that theblower 38 may be located either prior to the inlet or after the outlet, ofgas flow chamber 72. It is generally desirable for the air ingas flow chamber 72 and the water incoolant flow chamber 74 to flow in counter flow relation to one another for maximum efficiency of the ERD, though other configurations are within the scope of the invention. - Referring further to the operation of
power plant 110 with the inclusion of thehumidifying device 70, it is now possible to both relatively increase the dew point/humidity of the oxidant prior to its entry intocathode 18 and further cool the coolant leaving theradiator 152 prior to its entry intocoolant channel 22. This results in the redistribution of heat in the power plant, and particularly theCSA 12, thecoolant loop 114, and thefan 156 andradiator 152 within the coolant loop. This redistribution of the heat is illustrated by a comparison of the temperatures at various locations in thepower plant 110 ofFIG. 4 relative to the temperatures at similar locations in the power plant ofFIG. 1 . It is now seen that the humidification of the oxidant prior to its introduction tocathode 18 results in a temperature of about 130° F. (54.5° C.) onconduit 134′ at thecathode inlet 36, which in turn requires less heat from the coolant to complete the humidification process inCSA 12 and thus results in a higher grade heat, i.e., 165° F. (74° C.), as the source temperature of thecoolant exiting CSA 12 atcoolant outlet 50. This higher-grade heat in the coolant similarly appears incoolant loop portion 14″ at the inlet to theradiator 152 and, because the ambient air fromfan 156 remains at 120° F. (49° C.) (the sink temperature), the temperature difference therebetween is relatively increased. This enables theradiator 152 to effect the same amount of cooling, i.e., a drop of about 25° F. (14° C.) to 140° F. (60° C.) at its outlet onloop portion 114′″, with a radiator of relatively smaller capacity than that required for the same temperature drop across theradiator 52 ofFIG. 1 . This is accomplished because even though the temperature of thecoolant leaving radiator 152 is 5° F. (3° C.) higher than the 135° F. (57° C.) temperature desired for the coolant entering thecoolant channel 22 atinlet 48, that desired temperature (135° F., 57° C.) is attained when the coolant fromcoolant loop portion 114′″ passes through thecoolant flow chamber 74 ofhumidifier 70 and exits intocoolant loop portion 114″″. That further cooling of the coolant occurs as the result of the heat removed therefrom during the oxidant humidification process inERD 70, as described earlier. - In view of the forgoing discussion, it will be appreciated that the fuel
cell power plant 110 may be operated as satisfactorily as was thepower plant 10, yet with a relatively smaller andsimpler radiator 152/motorizedfan 156 than was the case inpower plant 10, and at an additional “cost” of only a relatively simple, compact, and inexpensive ERD/humidifier 70. On balance, the reduced size and cost of theradiator 152/fan 156 is typically a net advantage over any increased cost and size of the addedhumidifier 70. - Although the invention has been described and illustrated with respect to the exemplary embodiments thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions and additions may be made without departing from the spirit and scope of the invention. For example, the
radiator 52 of the heat removal means may be any of numerous types of heat exchangers, e.g., liquid to liquid, liquid to gas, etc. Moreover, thehumidifying device 70 may take various forms, including the fine pore saturator medium of an ERD, the water transfer plates as in a CSA, a bubble saturator, or the like, as well as others.
Claims (3)
1. In a fuel cell power plant (110) including a fuel cell stack assembly (12); an inlet oxidant stream (134,134′) operatively connected to a fuel cell stack assembly oxidant region inlet (36); a coolant loop (114) operatively connected to a fuel cell stack assembly coolant region inlet (48) and outlet (50), the coolant loop (114) including a radiator (152, 156) configured as a sink to transfer heat from a fuel cell stack assembly coolant at a source temperature to a sink temperature lower than the source temperature, the difference between said source temperature and said sink temperature being a temperature differential, a method of relatively increasing said temperature differential comprising the steps of:
cooling (74) the coolant in the coolant loop (114) by heat and mass transfer subsequent to passing the radiator (152, 156) and prior to return introduction of the coolant to the fuel cell stack assembly (12); and
relatively increasing the temperature and humidity (72) of the inlet oxidant stream (134′) prior to introduction of the inlet oxidant stream to the fuel cell stack assembly oxidant region inlet (36), thereby to distribute the heat of at least the fuel cell stack assembly (12) and the radiator (152, 156) so as to relatively increase the coolant exit temperature from the fuel cell stack assembly (12) and to the radiator (152, 156) so as to relatively increase said temperature differential between the source temperature and the sink temperature.
2. The method of claim 1 wherein the steps of cooling (74) the coolant in the coolant loop (114) by heat and mass transfer subsequent to passing the radiator (152, 156) and prior to return introduction of the coolant to the fuel cell stack assembly (12) and of relatively increasing the temperature and humidity (72) of the inlet oxidant stream (134,134′) prior to introduction of the inlet oxidant stream to the fuel cell stack assembly oxidant region inlet (36) comprise flowing the coolant and the oxidant stream through a humidifier (70) connected in the coolant loop (114) between the radiator (152, 156) and the coolant region inlet (48) and in the inlet oxidant stream (134′) to perform both steps.
3. In a fuel cell power plant (110) including a fuel cell stack assembly (12); an inlet oxidant stream (134,134′) operatively connected to a fuel cell stack assembly oxidant region inlet (36); a coolant loop (114) operatively connected to a fuel cell stack assembly coolant region inlet (48) and outlet (50), the coolant loop (114) including a radiator (152, 156) configured as a sink to transfer heat from a fuel cell stack assembly coolant at a source temperature to a sink temperature lower than the source temperature, the difference between said source temperature and said sink temperature being a temperature differential, a method of relatively increasing said temperature differential comprising the steps of:
cooling (74) the coolant in the coolant loop (114) subsequent to passing the radiator (152, 156) and prior to return introduction of the coolant to the fuel cell stack assembly (12); and
relatively increasing the temperature and humidity (72) of the inlet oxidant stream (134′) prior to introduction of the inlet oxidant stream to the fuel cell stack assembly oxidant region inlet (36), thereby to distribute the heat of at least the fuel cell stack assembly (12) and the radiator (152, 156) so as to relatively increase the coolant exit temperature from the fuel cell stack assembly (12) and to the radiator (152, 156) so as to relatively increase said temperature differential between the source temperature and the sink temperature; and
said steps of cooling (74) the coolant in the coolant loop (114) subsequent to passing the radiator (152, 156) and prior to return introduction of the coolant to the fuel cell stack assembly (12) and of relatively increasing the temperature and humidity (72) of the inlet oxidant stream (134,134′) prior to introduction of the inlet oxidant stream to the fuel cell stack assembly oxidant region inlet (36) comprise flowing both the coolant and the oxidant stream through a humidifier (70) connected in the coolant loop (114) and in the inlet oxidant stream (134′) to perform both steps.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/803,640 US20100279190A1 (en) | 2003-11-26 | 2010-07-01 | Cathode saturation arrangement for fuel cell power plant |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/723,081 US7014933B2 (en) | 2003-11-26 | 2003-11-26 | Cathode saturation arrangement for fuel cell power plant |
US11/327,912 US20060121323A1 (en) | 2003-11-26 | 2006-01-09 | Cathode saturation arrangement for fuel cell power plant |
US11/787,570 US20080171238A1 (en) | 2003-11-26 | 2007-04-17 | Cathode saturation arrangement for fuel cell power plant |
US12/803,640 US20100279190A1 (en) | 2003-11-26 | 2010-07-01 | Cathode saturation arrangement for fuel cell power plant |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US11/787,570 Continuation US20080171238A1 (en) | 2003-11-26 | 2007-04-17 | Cathode saturation arrangement for fuel cell power plant |
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US20100279190A1 true US20100279190A1 (en) | 2010-11-04 |
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US10/723,081 Expired - Lifetime US7014933B2 (en) | 2003-11-26 | 2003-11-26 | Cathode saturation arrangement for fuel cell power plant |
US11/327,912 Abandoned US20060121323A1 (en) | 2003-11-26 | 2006-01-09 | Cathode saturation arrangement for fuel cell power plant |
US11/787,570 Abandoned US20080171238A1 (en) | 2003-11-26 | 2007-04-17 | Cathode saturation arrangement for fuel cell power plant |
US12/803,640 Abandoned US20100279190A1 (en) | 2003-11-26 | 2010-07-01 | Cathode saturation arrangement for fuel cell power plant |
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US10/723,081 Expired - Lifetime US7014933B2 (en) | 2003-11-26 | 2003-11-26 | Cathode saturation arrangement for fuel cell power plant |
US11/327,912 Abandoned US20060121323A1 (en) | 2003-11-26 | 2006-01-09 | Cathode saturation arrangement for fuel cell power plant |
US11/787,570 Abandoned US20080171238A1 (en) | 2003-11-26 | 2007-04-17 | Cathode saturation arrangement for fuel cell power plant |
Country Status (4)
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US (4) | US7014933B2 (en) |
JP (1) | JP2007534117A (en) |
DE (1) | DE112004002303T5 (en) |
WO (1) | WO2005055333A2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
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US9947946B2 (en) | 2013-06-27 | 2018-04-17 | Dana Canada Corporation | Integrated gas management device for a fuel cell system |
Families Citing this family (4)
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JP4868251B2 (en) * | 2005-10-21 | 2012-02-01 | トヨタ自動車株式会社 | Fuel cell system, anode gas generation amount estimation device, and anode gas generation amount estimation method |
US7846603B2 (en) * | 2007-03-19 | 2010-12-07 | Gm Global Technology Operations, Inc. | Coolant reservoir purge system for fuel cell systems and vehicles |
US20140045084A1 (en) * | 2011-04-26 | 2014-02-13 | United Technologies Corporation | Internal steam generation for fuel cell |
WO2013061170A1 (en) * | 2011-10-24 | 2013-05-02 | Tata Motors Limited | An air humidification system of a fuel cell stack and method thereof |
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US6207308B1 (en) * | 1999-04-20 | 2001-03-27 | International Fuel Cells, Llc | Water treatment system for a fuel cell assembly |
US6428916B1 (en) * | 1999-12-20 | 2002-08-06 | Utc Fuel Cells, Llc | Coolant treatment system for a direct antifreeze cooled fuel cell assembly |
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US3677823A (en) * | 1969-10-06 | 1972-07-18 | United Aircraft Corp | Fuel saturator for low temperature fuel cells |
US4001041A (en) * | 1975-02-12 | 1977-01-04 | United Technologies Corporation | Pressurized fuel cell power plant |
US4011041A (en) * | 1975-06-16 | 1977-03-08 | Tifcon Company | Tobacco curing and drying apparatus |
US4530886A (en) * | 1984-12-06 | 1985-07-23 | United Technologies Corporation | Process for humidifying a gaseous fuel stream |
US4539267A (en) * | 1984-12-06 | 1985-09-03 | United Technologies Corporation | Process for generating steam in a fuel cell powerplant |
US5382478A (en) * | 1992-11-03 | 1995-01-17 | Ballard Power Systems Inc. | Electrochemical fuel cell stack with humidification section located upstream from the electrochemically active section |
US5573866A (en) * | 1995-05-08 | 1996-11-12 | International Fuel Cells Corp. | Direct methanol oxidation polymer electrolyte membrane power system |
US6048383A (en) * | 1998-10-08 | 2000-04-11 | International Fuel Cells, L.L.C. | Mass transfer composite membrane for a fuel cell power plant |
WO2000022152A1 (en) * | 1998-10-13 | 2000-04-20 | Avigen, Inc. | Compositions and methods for producing recombinant adeno-associated virus |
US6329090B1 (en) * | 1999-09-03 | 2001-12-11 | Plug Power Llc | Enthalpy recovery fuel cell system |
US6274259B1 (en) * | 1999-09-14 | 2001-08-14 | International Fuel Cells Llc | Fine pore enthalpy exchange barrier |
US6416892B1 (en) * | 2000-07-28 | 2002-07-09 | Utc Fuel Cells, Llc | Interdigitated enthally exchange device for a fuel cell power plant |
-
2003
- 2003-11-26 US US10/723,081 patent/US7014933B2/en not_active Expired - Lifetime
-
2004
- 2004-11-17 JP JP2006541374A patent/JP2007534117A/en active Pending
- 2004-11-17 DE DE112004002303T patent/DE112004002303T5/en not_active Withdrawn
- 2004-11-17 WO PCT/US2004/038717 patent/WO2005055333A2/en active Application Filing
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2006
- 2006-01-09 US US11/327,912 patent/US20060121323A1/en not_active Abandoned
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- 2007-04-17 US US11/787,570 patent/US20080171238A1/en not_active Abandoned
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2010
- 2010-07-01 US US12/803,640 patent/US20100279190A1/en not_active Abandoned
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
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US6207308B1 (en) * | 1999-04-20 | 2001-03-27 | International Fuel Cells, Llc | Water treatment system for a fuel cell assembly |
US6428916B1 (en) * | 1999-12-20 | 2002-08-06 | Utc Fuel Cells, Llc | Coolant treatment system for a direct antifreeze cooled fuel cell assembly |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
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US9947946B2 (en) | 2013-06-27 | 2018-04-17 | Dana Canada Corporation | Integrated gas management device for a fuel cell system |
Also Published As
Publication number | Publication date |
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JP2007534117A (en) | 2007-11-22 |
US20060121323A1 (en) | 2006-06-08 |
US7014933B2 (en) | 2006-03-21 |
WO2005055333A3 (en) | 2005-09-01 |
US20050112437A1 (en) | 2005-05-26 |
WO2005055333A2 (en) | 2005-06-16 |
US20080171238A1 (en) | 2008-07-17 |
DE112004002303T5 (en) | 2006-09-28 |
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