EP1458045A2 - Catalytic combustor and fuel cell system - Google Patents
Catalytic combustor and fuel cell system Download PDFInfo
- Publication number
- EP1458045A2 EP1458045A2 EP03028645A EP03028645A EP1458045A2 EP 1458045 A2 EP1458045 A2 EP 1458045A2 EP 03028645 A EP03028645 A EP 03028645A EP 03028645 A EP03028645 A EP 03028645A EP 1458045 A2 EP1458045 A2 EP 1458045A2
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- EP
- European Patent Office
- Prior art keywords
- gas
- exhaust
- housing
- fuel
- oxidizer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN A CARRIER GAS OR AIR
- F23C13/00—Apparatus in which combustion takes place in the presence of catalytic material
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
- F23D14/46—Details, e.g. noise reduction means
- F23D14/62—Mixing devices; Mixing tubes
- F23D14/64—Mixing devices; Mixing tubes with injectors
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D2900/00—Special features of, or arrangements for burners using fluid fuels or solid fuels suspended in a carrier gas
- F23D2900/14—Special features of gas burners
- F23D2900/14021—Premixing burners with swirling or vortices creating means for fuel or air
Definitions
- the present invention relates to a catalytic combustor and a fuel cell system and, more particularly, to a catalytic combustor and a fuel cell system wherein mixed gas containing exhaust fuel and exhaust oxidizing agent from a fuel electrode and an oxidizer electrode of a fuel cell, respectively, is combusted using a catalyst.
- Japanese Patent Application Laid-Open Publication No. 2002-231294 discloses a structure wherein when discharging exhaust fuel, expelled from a fuel electrode of a fuel cell, to an outside through a purge conduit, exhaust fuel is combusted with a catalytic combustor.
- the present invention has been completed upon such studies by the present inventors and has an object to provide a catalytic combustor and a fuel cell system that can reliably combust exhaust fuel from a fuel cell in a catalytic combustor.
- one aspect of the present invention is a catalytic combustor comprising: a housing supplied with mixed gas including exhaust fuel gas from a fuel electrode of a fuel cell and exhaust oxidizer gas from an oxidizer electrode of the fuel cell; and a catalyst combusting the mixed gas, wherein at an area upstream of the catalyst, an inner periphery surface of the housing has a continuous shape, and at least one of the exhaust fuel gas and the exhaust oxidizer gas is supplied to the housing in a way to generate swirl flow in the mixed gas so as to swirl along the inner peripheral surface.
- another aspect of the present invention is a fuel cell system comprising: a fuel cell having a fuel electrode and an oxidizer electrode; and a catalytic combustor provided with: a housing supplied with mixed gas including exhaust fuel gas from a fuel electrode of a fuel cell and exhaust oxidizer gas from an oxidizer electrode of the fuel cell; and a catalyst combusting the mixed gas, wherein at an area upstream of the catalyst, an inner periphery surface of the housing has a continuous shape, and at least one of the exhaust fuel gas and the exhaust oxidizer gas is supplied to the housing in a way to generate swirl flow in the mixed gas so as to swirl along the inner peripheral surface.
- another aspect of the present invention is a method of supplying gas to a catalytic combustor provided with a housing supplied with mixed gas including exhaust fuel gas from a fuel electrode of a fuel cell and exhaust oxidizer gas from an oxidizer electrode of the fuel cell, and a catalyst combusting the mixed gas, wherein at an area upstream of the catalyst, an inner periphery surface of the housing has a continuous shape, the method comprising: supplying at least one of the exhaust fuel gas and the exhaust oxidizer gas to the housing so as to generate swirl flow to occur in the mixed gas so as to swirl along the inner peripheral surface.
- Fig. 1 is an overall structural view showing a fuel cell system S equipped with a catalytic combustor of the presently filed embodiment.
- a fuel cell 1 is comprised of an anode electrode 3, serving as a fuel electrode, and a cathode electrode 5 serving as an oxidizer electrode.
- An inlet 3a of the anode electrode 3 is supplied with fuel gas from a fuel gas supply unit 7 via a fuel gas supply conduit 9 and an inlet 5a of the cathode electrode 5 is supplied with oxidizing agent gas from an oxidizing agent gas supply unit 11 via an oxidizing agent gas supply conduit 13, thereby permitting the fuel cell 1 to achieve electrochemical reaction to generate electric power.
- hydrogen gas is used as fuel gas
- air is used as oxidizing agent gas (oxidizer).
- an electrolyte layer 4 interleaved between the anode electrode 3 and the cathode electrode 5 is an electrolyte layer 4, and a plurality of structural bodies, each composed of the anode electrode 3, the electrolyte 4 and the cathode electrode 5, may be employed in a stack via a separator, which is not shown, for suitably intervening between the adjacently disposed structural bodies.
- anode off-gas which is not used and remains as exhaust fuel
- cathode off-gas which is not used and remains as exhaust oxidizing agent
- anode off-gas contains moisture content as a result of electric power generation.
- anode off-gas contains moisture content due to water that is reversely dispersed from the cathode electrode 5 to the anode electrode 3.
- anode off-gas recirculation conduit 17 Connected between the outlet 3b of the anode electrode 3 and the fuel gas supply conduit 9 is an anode off-gas recirculation conduit 17 that serves as a recirculation flow passage equipped with an anode off-gas recirculation device 15.
- a catalytic combustor 23 Connected to the anode off-gas recirculation device 15 through an anode off-gas supply conduit 21 through an anode off-gas exhaust valve 19, serving as an opening and closing valve, is a catalytic combustor 23.
- the catalytic combustor 23 and an outlet 5b of the cathode electrode 5 of the fuel cell 1 are connected to one another through a cathode off-gas supply conduit 25.
- An exhaust pipe 27 is connected to the catalytic combustor 23 at a position opposite to the inlet to which the cathode off-gas supply conduit 25 is connected.
- each functional component element of the fuel cell system is preferably controlled by a system controller 33.
- a voltage sensor 31 is disposed in the fuel cell 1 and if the voltage sensor 31 detects a lower voltage than a predetermined voltage, the system controller 33 is operative to open the anode off-gas exhaust valve 19 in response to a purge signal delivered from the system controller 33, thereby permitting anode off-gas to be supplied to the catalytic combustor 23 from the anode off-gas recirculation device 15 at a predetermined flow rate.
- Fig. 2A is a side cross sectional view showing an internal structure of the catalytic combustor 23, and Fig. 2B is a cross section taken on line A-A of Fig. 2A.
- the catalytic combustor 23 includes a housing 35 formed in a cylindrical shape symmetric with respect to a central axis CX.
- the cathode off-gas supply conduit 25 is connected to a substantially center of one end (an introducing end) 35a of the housing 35, and the exhaust pipe 27 is connected to a substantially center of the other end (an exhausting end) 35b.
- a catalyst 37 is accommodated in the housing 35 in an area closer to the exhaust pipe 27 for enabling combustion of mixed gas (especially anode off-gas) between anode off-gas and cathode off-gas.
- the anode off-gas supply conduit 21 with a circular cross section is inserted to an interior of the housing 35 through a cylindrical section 35c of the housing 35 at an area in the vicinity of the introducing end 35a.
- the nozzle 39 serving as a fuel supply port of the anode off-gas supply conduit 21 inserted to the interior of the housing 35 from the cylindrical section 35c, includes a base portion 39a extending toward a central portion of the housing 35 in a radial direction perpendicular to the central axis CX of the housing 35, a bent portion 39b bent from the base portion 39a toward the catalyst 37 at an angle of 90 degrees in a circular arc configuration, and a distal end portion 39c extending from the bent portion 39b toward the catalyst 37 so as to allow a distal end of the bent portion 39b to extend along the central axis CX so as to open to the catalyst 37, with a central axis of a circular cross section of the distal end 39c being held in alignment with the central axis CX
- Fig. 3A is a cross sectional view showing an internal structure of the distal end portion 39c of the nozzle 39 by which anode off-gas is supplied
- Fig. 3B is a cross sectional view taken on line B-B of Fig. 3A
- Fig. 3C is a cross sectional view taken on line C-C of Fig. 3A
- Fig. 3D is a cross sectional view taken on line D-D of Fig. 3A.
- the distal end portion 39c of the nozzle 39 takes the form of the same channel structure (flow passage structure) as that used for a so-called swirl type liquid injection valve and causes anode off-gas, supplied into the catalytic combustor 23, to generate a swirl flow along an inner peripheral wall of the cylindrical portion 35c.
- FIG. 3A and Fig. 3B that is the cross section, taken on line B-B, of Fig. 3A, formed on an upstream of the distal end portion 39c are communicating apertures 41, 41 that respectively extend in directions (directions perpendicular to a paper surface of the figure) parallel to the central axis CX at two upper and lower positions in the figure.
- FIG. 3A and Fig. 3C that is the cross section, taken along C-C, of Fig. 3A, formed on the distal end portion 39c at a position downstream of the communicating apertures 41, 41 in point symmetry with respect to the central axis CX are respectively communicating channels 43, 43, whose outer peripheral terminal portions 43a, 43a, as shown in Fig.
- FIG. 3C respectively communicate with the communicating apertures 41, 41, and which respectively extend in directions parallel to one another with a predetermined distance.
- inner peripheral terminal portions 43b, 43b of the respective communicating channels 43, 43, shown in Fig. 3C respectively communicate with an outer periphery of an ejector channel 45 located at a central position of the cylindrical portion 35c, as shown in Fig. 3D that is the cross section, taken on line D-D, of Fig. 3A.
- the ejector channel 45 extends parallel to the central axis CX to be in communication with an interior of the cylindrical portion 35c.
- anode off-gas ejecting from the ejector channel 45 is enabled to form swirl flow SW, of mixed gas also containing cathode off-gas, which flows into the cylindrical portion 35c of the housing 35 while swirling along the inner peripheral surface of the cylindrical portion 35c.
- the uppermost upstream portion (a portion extending along a circumferential direction of an inner periphery of the cylindrical portion 35c and shown as an upstream position P for the sake of convenience) of an area at which such resulting swirl flow SW impinges upon the inner peripheral surface of the cylindrical portion 35c is set to be located upstream (rightward in Fig. 2A) of the catalyst 37.
- annular protrusion 47 formed between the upstream position P of swirl flow SW and the catalyst 37 is an annular protrusion 47 that protrudes toward a center in the radial direction of the cylindrical portion 35c of the housing 35. Also, in the figure, typically, the protrusion 47 is shown as having a cross sectional shape in a triangular configuration.
- an entire flow of anode off-gas expelled from the outlet 3b of the anode electrode 3 is recirculated to the fuel gas recirculation conduit 9 via the anode off-gas recirculation conduit 17 by the anode off-gas recirculation device 15 and is supplied to the inlet 3a of the anode electrode 3 again.
- the fuel cell system provides improved fuel consumption.
- cathode off-gas expelled from the outlet 5b of the cathode electrode 5 has no recirculation line and exhausted to the outside of the fuel cell system through the catalytic combustor 23 and the exhaust pipe 27.
- the hydrogen concentration in anode off-gas to be recirculated through the anode off-gas recirculation device 15 drops equal to or below a predetermined concentration due to nitrogen or moisture reversely diffused to the anode electrode 3 from the cathode electrode 5, the result is that the output voltage of the fuel cell 1 tends to drop.
- the output voltage of such a fuel cell 1 is detected by the voltage sensor 31 and, if the system controller 33 discriminates that such a detected voltage is lower than a predetermined voltage level, the anode off-gas exhaust valve 19 is opened. This allows anode off-gas to be delivered through the anode off-gas supply conduit 21 from the anode off-gas recirculation device 15 at a predetermined flow rate to be mixed with cathode off-gas to form mixed gas, which is supplied to the catalytic combustor 23.
- anode off-gas delivered through the anode off-gas supply conduit 21 is discharged from the nozzle 39 that protrudes in the housing 35.
- anode off-gas reaches the communicating channels 43, 43 through the communicating apertures 41, 41 and when flowing through the communicating channels 43, 43 toward the center of the cylindrical portion 35c of the housing 35, anode off-gas flows out to the outer peripheral side of the ejecting channel 45 whereby anode off-gas flows toward the catalyst 37 in Fig. 2A and forms swirl flow SW that turns clockwise in Fig. 2B.
- Such condensed water is formed in a substantially hollow cone-shaped mist flow due to swirl flow SW and is dispersed in water droplets W toward the outer peripheral wall in the radial direction of the cylindrical portion 35c of the housing 35 in a way to reach the inner peripheral wall of the cylindrical portion 35c (schematically shown to remain in a regional area outside a dotted area in which swirl flow SW is present).
- condensed water can be avoided from directly reaching the catalyst 37 of the catalytic combustor 23 and the catalyst 37 can be prevented from being deteriorated in an activity, and thus, anode off-gas can be combusted in the catalyst 37 in a reliable manner.
- annular protrusion 47 being formed over the inner peripheral wall of the cylindrical portion 35c of the housing 35 at the area close proximity to the catalyst 37, even in the presence of a situation where water droplets W and a part of hollow cone-shaped mist flow, containing water droplets W, are probable to reach not only the inner peripheral wall of the cylindrical portion 35c, but also the catalyst 37, the water droplets W and the portion of hollow cone-shaped mist flow, which would tend to reach the catalyst 37, can be avoided from reaching the catalyst 37.
- the water droplets W and the hollow cone-shaped mist flow are blocked from traveling toward the catalyst 37, thereby enabling condensed water to be reliably avoided from being deposited to the catalyst 37.
- cathode off-gas flows into the upstream area of the catalytic combustor 23 and is mixed with anode off-gas prior to reaching the catalyst 37, condensed water contained in cathode off-gas is similarly dispersed in water droplets W to deposit onto the inner peripheral wall of the cylindrical portion 35c and is also blocked by the annular protrusion 47, water droplets W can be blocked by the annular protrusion 47 and prevented from being deposited onto the catalyst 37 in the same way as that achieved in respect of anode off-gas from which steam is blocked from getting the catalyst 37.
- the shape of the nozzle 39 disposed in the anode off-gas supply conduit 21 is not limited to a particular cylindrical shape and may take the form of a configuration to enables swirl flow to be creased with no excess and shortage.
- the number of pieces and layout of the communicating apertures 41 and the communicating channels 43 are not limitative, and these components may be arranged in a suitable number of pieces and layout capable for swirl flow to be generated.
- the housing 35 is not limited to a particular cylindrical shape and may be formed in a curved shape, which continuously varies, so as to enable swirl flow to turn, with no undesired attenuation caused in swirl flow, in the direction along the inner peripheral wall of the housing 35.
- the number of pieces and the shape of the annular protrusion 47 are not limitative and may be suffice to be formed in a suitable arrangement to enable water droplets from getting the catalyst.
- the presently filed embodiment mainly differs from the first embodiment in respect of a connecting structure of the anode of-gas supply conduit 21 and the cathode of-gas supply conduit 25 with respect to the housing 35 of the catalytic combustor 23, and a main differing point resides in that swirl flows are generated not only in anode off-gas but also in cathode off-gas, and the other structure is similar to that of the first embodiment.
- like component parts bear the same reference numerals as those of the first embodiment, with description being made in a suitably simplified fashion or omitted.
- Fig. 4A is a side cross sectional view showing an internal structure of the catalytic combustor 23 of the presently filed embodiment
- Fig. 4B is a cross section, taken on line E-E, of Fig. 4A
- Fig. 5 is an illustrative view showing a status where cathode off-gas flows in the catalytic combustor 23.
- the anode off-gas supply conduit 21 is connected to a central part of one end wall (introducing end wall) 35a of the housing 35 of the catalytic combustor 23 along the central axis CX and the nozzle 39, forming a fuel supply port, is inserted through the housing 35.
- the nozzle 39 extends on the central axis CX, with a distal end portion 39A having a structure, similar to that of the first embodiment shown in Fig. 3, which forms swirl flow SW swirling along the inner peripheral surface of the cylindrical portion 35c of the housing 35. That is, the distal end portion 39A of the nozzle 39 is provided with the communicating apertures 41, 41, the communicating channels 43, 43 and the ejector channel 45 in the same manner as shown in Fig. 3.
- the cathode off-gas supply conduit 25 is connected to the cylindrical portion 35c, in a way to be oriented along a deviated direction CA that is not directed toward the central axis CX of the cylindrical portion 35c, that is, with respect to the cylindrical portion 35c of the housing 35, in a way to extend along the direction CA that is perpendicular to the central axis CX of the cylindrical portion 35c as shown in Fig. 4A and separated from the central axis CX of the cylindrical portion 35c as shown in Fig. 4B.
- a distal end of the cathode off-gas supply conduit 25 has a discharge port 49 that serves as a supply section for supplying cathode off-gas involving oxidizing agent.
- the cathode off-gas supply conduit 25 is connected to the cylindrical portion 35c of the housing 35 with respect of the inner peripheral surface thereof such that, as shown in Fig. 4B, a right end portion, which forms the outermost area to cause swirl flow, extends along a tangential line of the inner peripheral surface of the cylindrical portion 35c while a left end portion, which forms the innermost area to cause swirl flow, terminates in the inner peripheral surface of the cylindrical portion 35c at a position displaced rightward from the central axis CX.
- the discharge port 49 of the cathode off-gas supply conduit 25 penetrates through the cylindrical portion 35c of the housing 35, and a boundary surface 49A between the cathode off-gas supply conduit 25 and the interior of the cylindrical portion 35c of the housing 35 lies along a part of the inner peripheral surface of the cylindrical portion 35c. Also, such a discharge port 49 is located at a position closer to the introducing end wall 35a of the housing 35 than the distal end 39A of the nozzle 39 as viewed in Fig. 4A.
- cathode off-gas ejecting from the discharge port 49 can be supplied into the housing 35 as swirl flow SWA, with no occurrence of undesired interference with swirl flow SW of anode off-gas, while swirling along the circumferential inner peripheral surface of the cylindrical portion 35c of the housing 35. Also, a direction in which swirl flow SWA of cathode off-gas shown in Fig. 5 occurs is clockwise, that is, in the same direction as that of swirl flow SW of anode off-gas.
- cathode off-gas when cathode off-gas is discharged into the catalytic combustor 23, it is conceived that steam in cathode off-gas is condensed in the cathode off-gas supply conduit 25 to form liquid water which enters the housing 35.
- Such condensed water is subject to swirl flow SWA of cathode off-gas and is dispersed by a centrifugal force, as shown in Fig. 5, to be formed into water droplets W that deposit to the inner peripheral surface of the cylindrical portion 35c of the housing 35.
- this avoids condensed water from directly reaching the catalyst 37 to preclude the catalyst 37 from loosing an activity, thereby enabling anode off-gas to be reliably combusted.
- the protrusion 47 which is formed on the inner peripheral wall of the cylindrical portion 35c of the housing 35 in an annular configuration at the area near the catalyst 37, blocks the flow of condensed water from traveling to the catalyst 37, thereby condensed water to be reliably protected from depositing to the catalyst 37.
- the presently filed embodiment mainly differs from the second embodiment in respect of a connecting structure of the anode of-gas supply conduit 21 and the cathode of-gas supply conduit 25 with respect to the housing 35 of the catalytic combustor 23, and a main different point resides in that, in order for swirl flow to be generated not only in anode off-gas but also in cathode off-gas, the anode off-gas supply conduit 21 and the cathode off-gas supply conduit 25 are concentrically connected to the housing 35, and the other structure is similar to the second embodiment.
- like component parts bear the same reference numerals as those of the first embodiment, with description being made in a suitably simplified form or omitted.
- the connecting structure, in the presently filed embodiment, of the cathode off-gas supply conduit 25 with respect to the housing 35 is identical to that of the cathode off-gas supply conduit 25 in the second embodiment shown in Fig. 4.
- the anode off-gas supply conduit 21 is located inside such structured cathode off-gas supply conduit 25 and connected to the housing 35 concentrically with the cathode off-gas supply conduit 25 along a central axis CX'.
- a nozzle 39B, forming a fuel supply port, of the anode off-gas supply conduit 21 is accommodated in the cathode off-gas supply conduit 25 so as to lie on the same plane as the boundary surface 49A of the discharge port 49 of the cathode off-gas supply conduit 25 or to be located in a position proximity to the boundary surface 49A at an area outside thereof.
- Such a layout position of the nozzle 39B of the anode off-gas supply conduit 21 is determined so as to assume a position such that a direction in which anode off-gas is supplied into the cylindrical portion 35c is oriented in substantially the same direction as the direction in which cathode off-gas is supplied through the discharge port 49 of the cathode off-gas supply conduit 25 whereby swirl flow is formed in anode off-gas per se without undesirably and adversely affecting swirl flow of cathode off-gas.
- a direction in which anode off-gas is supplied through the nozzle 39B of the anode off-gas supply conduit 21 is oriented in the same direction as the direction in which cathode off-gas is supplied through the discharge port 49 of the cathode off-gas supply conduit 25 to allow anode off-gas to be supplied into the housing 35 along the circular inner peripheral surface of the cylindrical portion 35c of the housing 35 and mixed with cathode off-gas to form mixed gas with swirl flow SW swirling along the inner peripheral surface of the cylindrical portion 35c of the housing 35 being formed.
- the cathode off-gas supply conduit 25 may be disposed inside the anode off-gas supply conduit 21.
- an inner peripheral shape, in cross section, of the housing of the catalytic combustor, intersecting a direction in which mixed gas between exhaust fuel and exhaust air flows into the catalyst is typically formed to have the substantially circular configuration to allow exhaust fuel and exhaust air to be supplied to the interior of the housing at the areas upstream of the catalyst of the catalytic combustor such that swirl flow occurs along the inner peripheral surface of the housing, condensed water involved in exhaust fuel and exhaust air can be dispersed toward the outer peripheral side of the housing to avoid condensed water from adhering to the catalyst for thereby precluding the catalyst from deteriorated in activity, thereby enabling mixed gas, especially exhaust fuel, expelled from the fuel cell to be reliably combusted.
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Abstract
A catalytic combustor is provided with a housing supplied with mixed gas including exhaust
fuel gas from a fuel electrode of a fuel cell and exhaust oxidizer gas from an oxidizer electrode
of the fuel cell, and a catalyst combusting the mixed gas. At an area upstream of the catalyst, an
inner periphery surface of the housing has a continuous shape, and at least one of the exhaust
fuel gas and the exhaust oxidizer gas is supplied to the housing in a way to generate swirl flow
in the mixed gas so as to swirl along the inner peripheral surface. Such a catalytic combustor is
applied to a fuel cell system provided with a fuel cell having a fuel electrode and an oxidizer
electrode.
Description
- The present invention relates to a catalytic combustor and a fuel cell system and, more particularly, to a catalytic combustor and a fuel cell system wherein mixed gas containing exhaust fuel and exhaust oxidizing agent from a fuel electrode and an oxidizer electrode of a fuel cell, respectively, is combusted using a catalyst.
- Japanese Patent Application Laid-Open Publication No. 2002-231294 discloses a structure wherein when discharging exhaust fuel, expelled from a fuel electrode of a fuel cell, to an outside through a purge conduit, exhaust fuel is combusted with a catalytic combustor.
- However, according to the present inventors, such a structure is conceived to encounter a tendency in that if the catalytic combustor is intermittently supplied with exhaust fuel each for a short time interval, water generated through condensation of exhaust fuel enters an interior of the catalytic combustor with a resultant loss in an activity of a catalyst due to water being absorbed therein.
- The present invention has been completed upon such studies by the present inventors and has an object to provide a catalytic combustor and a fuel cell system that can reliably combust exhaust fuel from a fuel cell in a catalytic combustor.
- To achieve the above object, one aspect of the present invention is a catalytic combustor comprising: a housing supplied with mixed gas including exhaust fuel gas from a fuel electrode of a fuel cell and exhaust oxidizer gas from an oxidizer electrode of the fuel cell; and a catalyst combusting the mixed gas, wherein at an area upstream of the catalyst, an inner periphery surface of the housing has a continuous shape, and at least one of the exhaust fuel gas and the exhaust oxidizer gas is supplied to the housing in a way to generate swirl flow in the mixed gas so as to swirl along the inner peripheral surface.
- In the meantime, another aspect of the present invention is a fuel cell system comprising: a fuel cell having a fuel electrode and an oxidizer electrode; and a catalytic combustor provided with: a housing supplied with mixed gas including exhaust fuel gas from a fuel electrode of a fuel cell and exhaust oxidizer gas from an oxidizer electrode of the fuel cell; and a catalyst combusting the mixed gas, wherein at an area upstream of the catalyst, an inner periphery surface of the housing has a continuous shape, and at least one of the exhaust fuel gas and the exhaust oxidizer gas is supplied to the housing in a way to generate swirl flow in the mixed gas so as to swirl along the inner peripheral surface.
- On the other hand, another aspect of the present invention is a method of supplying gas to a catalytic combustor provided with a housing supplied with mixed gas including exhaust fuel gas from a fuel electrode of a fuel cell and exhaust oxidizer gas from an oxidizer electrode of the fuel cell, and a catalyst combusting the mixed gas, wherein at an area upstream of the catalyst, an inner periphery surface of the housing has a continuous shape, the method comprising: supplying at least one of the exhaust fuel gas and the exhaust oxidizer gas to the housing so as to generate swirl flow to occur in the mixed gas so as to swirl along the inner peripheral surface.
- Other and further features, advantages, and benefits of the present invention will become more apparent from the following description taken in conjunction with the following drawings.
-
- Fig. 1 is an overall structural view showing a fuel cell system equipped with a catalytic combustor of a first embodiment according to the present invention;
- Fig. 2A is a side cross sectional view showing an internal structure of the catalytic combustor shown in Fig. 1, and Fig. 2B is a cross sectional view taken on a line A-A of Fig. 2A, respectively in the first embodiment;
- Fig. 3A is a cross sectional view showing an internal structure of a nozzle distal end of the catalytic combustor that supplies anode off-gas, Fig. 3B is a cross sectional view taken on a line B-B of Fig. 3A, Fig. 3C is a cross sectional view taken on a line C-C of Fig. 3A and Fig. 3D is a cross sectional view taken on a line D-D of Fig. 3A, respectively in the first embodiment;
- Fig. 4A is a side cross sectional view showing an internal structure of a catalytic combustor of a second embodiment according to the present invention, and Fig. 4B is a cross sectional view taken on line E-E of Fig. 4A in the second embodiment;
- Fig. 5 is an illustrative view showing a state where cathode off-gas flows in the catalytic combustor of the second embodiment;
- Fig. 6A is a side cross sectional view showing an internal structure of a catalytic combustor of a third embodiment of the present invention and Fig. 6B is a cross sectional view taken on line F-F of Fig. 6A in the third embodiment; and
- Fig. 7 is an illustrative view showing a state where cathode off-gas and anode off-gas flow in a catalytic combustor of the third embodiment.
-
- A catalytic combustor and a fuel cell system of each embodiment according to the present invention are described hereunder with reference to Figs. 1 to 7.
- First, a catalytic combustor and a fuel cell system of a first embodiment according to the present invention are described in detail with reference to Figs. 1 to 3D.
- Fig. 1 is an overall structural view showing a fuel cell system S equipped with a catalytic combustor of the presently filed embodiment.
- In Fig. 1, a
fuel cell 1 is comprised of ananode electrode 3, serving as a fuel electrode, and acathode electrode 5 serving as an oxidizer electrode. Aninlet 3a of theanode electrode 3 is supplied with fuel gas from a fuelgas supply unit 7 via a fuel gas supply conduit 9 and aninlet 5a of thecathode electrode 5 is supplied with oxidizing agent gas from an oxidizing agentgas supply unit 11 via an oxidizing agentgas supply conduit 13, thereby permitting thefuel cell 1 to achieve electrochemical reaction to generate electric power. Here, hydrogen gas is used as fuel gas, and air is used as oxidizing agent gas (oxidizer). Incidentally, interleaved between theanode electrode 3 and thecathode electrode 5 is anelectrolyte layer 4, and a plurality of structural bodies, each composed of theanode electrode 3, theelectrolyte 4 and thecathode electrode 5, may be employed in a stack via a separator, which is not shown, for suitably intervening between the adjacently disposed structural bodies. - During electric power generation of the
fuel cell 1, anode off-gas, which is not used and remains as exhaust fuel, is expelled from anoutlet 3b of theanode electrode 3, and cathode off-gas, which is not used and remains as exhaust oxidizing agent, is expelled from anoutlet 5b of thecathode 5. Further, typically, when using a solid polymer electrolyte of a proton conductivity as electrolyte of theelectrolyte layer 4, cathode off-gas contains moisture content as a result of electric power generation. Additionally, it is conceived that anode off-gas contains moisture content due to water that is reversely dispersed from thecathode electrode 5 to theanode electrode 3. - Connected between the
outlet 3b of theanode electrode 3 and the fuel gas supply conduit 9 is an anode off-gas recirculation conduit 17 that serves as a recirculation flow passage equipped with an anode off-gas recirculation device 15. - Connected to the anode off-
gas recirculation device 15 through an anode off-gas supply conduit 21 through an anode off-gas exhaust valve 19, serving as an opening and closing valve, is acatalytic combustor 23. - The
catalytic combustor 23 and anoutlet 5b of thecathode electrode 5 of thefuel cell 1 are connected to one another through a cathode off-gas supply conduit 25. Anexhaust pipe 27 is connected to thecatalytic combustor 23 at a position opposite to the inlet to which the cathode off-gas supply conduit 25 is connected. - Incidentally, each functional component element of the fuel cell system is preferably controlled by a
system controller 33. Typically, in respect of control of the anode off-gas exhaust valve 19, avoltage sensor 31 is disposed in thefuel cell 1 and if thevoltage sensor 31 detects a lower voltage than a predetermined voltage, thesystem controller 33 is operative to open the anode off-gas exhaust valve 19 in response to a purge signal delivered from thesystem controller 33, thereby permitting anode off-gas to be supplied to thecatalytic combustor 23 from the anode off-gas recirculation device 15 at a predetermined flow rate. - Fig. 2A is a side cross sectional view showing an internal structure of the
catalytic combustor 23, and Fig. 2B is a cross section taken on line A-A of Fig. 2A. - As shown in Figs. 2A and 2B, the
catalytic combustor 23 includes ahousing 35 formed in a cylindrical shape symmetric with respect to a central axis CX. The cathode off-gas supply conduit 25 is connected to a substantially center of one end (an introducing end) 35a of thehousing 35, and theexhaust pipe 27 is connected to a substantially center of the other end (an exhausting end) 35b. And, acatalyst 37 is accommodated in thehousing 35 in an area closer to theexhaust pipe 27 for enabling combustion of mixed gas (especially anode off-gas) between anode off-gas and cathode off-gas. - On the other hand, the anode off-
gas supply conduit 21 with a circular cross section is inserted to an interior of thehousing 35 through acylindrical section 35c of thehousing 35 at an area in the vicinity of the introducingend 35a. Thenozzle 39, serving as a fuel supply port of the anode off-gas supply conduit 21 inserted to the interior of thehousing 35 from thecylindrical section 35c, includes abase portion 39a extending toward a central portion of thehousing 35 in a radial direction perpendicular to the central axis CX of thehousing 35, abent portion 39b bent from thebase portion 39a toward thecatalyst 37 at an angle of 90 degrees in a circular arc configuration, and adistal end portion 39c extending from thebent portion 39b toward thecatalyst 37 so as to allow a distal end of thebent portion 39b to extend along the central axis CX so as to open to thecatalyst 37, with a central axis of a circular cross section of thedistal end 39c being held in alignment with the central axis CX of the circular cross section of thehousing 35. - Fig. 3A is a cross sectional view showing an internal structure of the
distal end portion 39c of thenozzle 39 by which anode off-gas is supplied, Fig. 3B is a cross sectional view taken on line B-B of Fig. 3A, Fig. 3C is a cross sectional view taken on line C-C of Fig. 3A, and Fig. 3D is a cross sectional view taken on line D-D of Fig. 3A. - In Figs. 3A to 3D, the
distal end portion 39c of thenozzle 39 takes the form of the same channel structure (flow passage structure) as that used for a so-called swirl type liquid injection valve and causes anode off-gas, supplied into thecatalytic combustor 23, to generate a swirl flow along an inner peripheral wall of thecylindrical portion 35c. - That is, as shown in Fig. 3A and Fig. 3B that is the cross section, taken on line B-B, of Fig. 3A, formed on an upstream of the
distal end portion 39c are communicatingapertures distal end portion 39c at a position downstream of the communicatingapertures channels terminal portions apertures terminal portions channels ejector channel 45 located at a central position of thecylindrical portion 35c, as shown in Fig. 3D that is the cross section, taken on line D-D, of Fig. 3A. Theejector channel 45 extends parallel to the central axis CX to be in communication with an interior of thecylindrical portion 35c. - With such a structure of the
distal end portion 39c of thenozzle 39, anode off-gas ejecting from theejector channel 45 is enabled to form swirl flow SW, of mixed gas also containing cathode off-gas, which flows into thecylindrical portion 35c of thehousing 35 while swirling along the inner peripheral surface of thecylindrical portion 35c. The uppermost upstream portion (a portion extending along a circumferential direction of an inner periphery of thecylindrical portion 35c and shown as an upstream position P for the sake of convenience) of an area at which such resulting swirl flow SW impinges upon the inner peripheral surface of thecylindrical portion 35c is set to be located upstream (rightward in Fig. 2A) of thecatalyst 37. - Still also, formed between the upstream position P of swirl flow SW and the
catalyst 37 is anannular protrusion 47 that protrudes toward a center in the radial direction of thecylindrical portion 35c of thehousing 35. Also, in the figure, typically, theprotrusion 47 is shown as having a cross sectional shape in a triangular configuration. - Next, operation of the above-described structure of the fuel cell system S is described in detail.
- During normal operation of the fuel cell system, an entire flow of anode off-gas expelled from the
outlet 3b of theanode electrode 3 is recirculated to the fuel gas recirculation conduit 9 via the anode off-gas recirculation conduit 17 by the anode off-gas recirculation device 15 and is supplied to theinlet 3a of theanode electrode 3 again. With such a structure, during normal operation, the fuel cell system provides improved fuel consumption. - In the meanwhile, cathode off-gas expelled from the
outlet 5b of thecathode electrode 5 has no recirculation line and exhausted to the outside of the fuel cell system through thecatalytic combustor 23 and theexhaust pipe 27. - Here, if the hydrogen concentration in anode off-gas to be recirculated through the anode off-
gas recirculation device 15 drops equal to or below a predetermined concentration due to nitrogen or moisture reversely diffused to theanode electrode 3 from thecathode electrode 5, the result is that the output voltage of thefuel cell 1 tends to drop. - The output voltage of such a
fuel cell 1 is detected by thevoltage sensor 31 and, if thesystem controller 33 discriminates that such a detected voltage is lower than a predetermined voltage level, the anode off-gas exhaust valve 19 is opened. This allows anode off-gas to be delivered through the anode off-gas supply conduit 21 from the anode off-gas recirculation device 15 at a predetermined flow rate to be mixed with cathode off-gas to form mixed gas, which is supplied to thecatalytic combustor 23. - In the
catalytic combustor 23, anode off-gas delivered through the anode off-gas supply conduit 21 is discharged from thenozzle 39 that protrudes in thehousing 35. Inside thenozzle 39, as shown in Figs. 3A to 3D, anode off-gas reaches the communicatingchannels apertures channels cylindrical portion 35c of thehousing 35, anode off-gas flows out to the outer peripheral side of the ejectingchannel 45 whereby anode off-gas flows toward thecatalyst 37 in Fig. 2A and forms swirl flow SW that turns clockwise in Fig. 2B. - That is, such swirl flow SW flows out into the
cylindrical portion 35c of thehousing 35 through theejector channel 45. - Here, when supplying anode off-gas to the
catalytic combustor 23, it is conceived that steam contained in anode off-gas is condensed in the anode off-gas supply conduit 21 to form liquid water that is to enter thehousing 35. - Such condensed water is formed in a substantially hollow cone-shaped mist flow due to swirl flow SW and is dispersed in water droplets W toward the outer peripheral wall in the radial direction of the
cylindrical portion 35c of thehousing 35 in a way to reach the inner peripheral wall of thecylindrical portion 35c (schematically shown to remain in a regional area outside a dotted area in which swirl flow SW is present). With such a structure, condensed water can be avoided from directly reaching thecatalyst 37 of thecatalytic combustor 23 and thecatalyst 37 can be prevented from being deteriorated in an activity, and thus, anode off-gas can be combusted in thecatalyst 37 in a reliable manner. - Still also, here, with the
annular protrusion 47 being formed over the inner peripheral wall of thecylindrical portion 35c of thehousing 35 at the area close proximity to thecatalyst 37, even in the presence of a situation where water droplets W and a part of hollow cone-shaped mist flow, containing water droplets W, are probable to reach not only the inner peripheral wall of thecylindrical portion 35c, but also thecatalyst 37, the water droplets W and the portion of hollow cone-shaped mist flow, which would tend to reach thecatalyst 37, can be avoided from reaching thecatalyst 37. With such a structure, the water droplets W and the hollow cone-shaped mist flow are blocked from traveling toward thecatalyst 37, thereby enabling condensed water to be reliably avoided from being deposited to thecatalyst 37. - Further, in the meanwhile, it is supposed that when cathode off-gas is discharged toward the
catalytic combustor 23, steam contained in cathode off-gas is condensed in the cathode off-gas supply conduit 25 to form liquid water which flows into thehousing 35. Inside thehousing 35, since because of the presence of swirl flow SW, cathode off-gas flows into the upstream area of thecatalytic combustor 23 and is mixed with anode off-gas prior to reaching thecatalyst 37, condensed water contained in cathode off-gas is similarly dispersed in water droplets W to deposit onto the inner peripheral wall of thecylindrical portion 35c and is also blocked by theannular protrusion 47, water droplets W can be blocked by theannular protrusion 47 and prevented from being deposited onto thecatalyst 37 in the same way as that achieved in respect of anode off-gas from which steam is blocked from getting thecatalyst 37. - Incidentally, no limitation for the shapes, positional relationships and the number of pieces of various component parts of the presently filed embodiment is intended, and other shapes or the like may be used provided that similar functions are exhibited. The shape of the
nozzle 39 disposed in the anode off-gas supply conduit 21 is not limited to a particular cylindrical shape and may take the form of a configuration to enables swirl flow to be creased with no excess and shortage. The number of pieces and layout of the communicatingapertures 41 and the communicatingchannels 43 are not limitative, and these components may be arranged in a suitable number of pieces and layout capable for swirl flow to be generated. Thehousing 35 is not limited to a particular cylindrical shape and may be formed in a curved shape, which continuously varies, so as to enable swirl flow to turn, with no undesired attenuation caused in swirl flow, in the direction along the inner peripheral wall of thehousing 35. The number of pieces and the shape of theannular protrusion 47 are not limitative and may be suffice to be formed in a suitable arrangement to enable water droplets from getting the catalyst. - Next, a catalytic combustor and a fuel cell system of a second embodiment according to the present invention are described below in detail with reference to Figs. 4A to 5. The presently filed embodiment mainly differs from the first embodiment in respect of a connecting structure of the anode of-
gas supply conduit 21 and the cathode of-gas supply conduit 25 with respect to thehousing 35 of thecatalytic combustor 23, and a main differing point resides in that swirl flows are generated not only in anode off-gas but also in cathode off-gas, and the other structure is similar to that of the first embodiment. Thus, like component parts bear the same reference numerals as those of the first embodiment, with description being made in a suitably simplified fashion or omitted. - Fig. 4A is a side cross sectional view showing an internal structure of the
catalytic combustor 23 of the presently filed embodiment, Fig. 4B is a cross section, taken on line E-E, of Fig. 4A and Fig. 5 is an illustrative view showing a status where cathode off-gas flows in thecatalytic combustor 23. - As shown in Figs. 4A and 4B, the anode off-
gas supply conduit 21 is connected to a central part of one end wall (introducing end wall) 35a of thehousing 35 of thecatalytic combustor 23 along the central axis CX and thenozzle 39, forming a fuel supply port, is inserted through thehousing 35. Thenozzle 39 extends on the central axis CX, with adistal end portion 39A having a structure, similar to that of the first embodiment shown in Fig. 3, which forms swirl flow SW swirling along the inner peripheral surface of thecylindrical portion 35c of thehousing 35. That is, thedistal end portion 39A of thenozzle 39 is provided with the communicatingapertures channels ejector channel 45 in the same manner as shown in Fig. 3. - In the meanwhile, the cathode off-
gas supply conduit 25 is connected to thecylindrical portion 35c, in a way to be oriented along a deviated direction CA that is not directed toward the central axis CX of thecylindrical portion 35c, that is, with respect to thecylindrical portion 35c of thehousing 35, in a way to extend along the direction CA that is perpendicular to the central axis CX of thecylindrical portion 35c as shown in Fig. 4A and separated from the central axis CX of thecylindrical portion 35c as shown in Fig. 4B. A distal end of the cathode off-gas supply conduit 25 has adischarge port 49 that serves as a supply section for supplying cathode off-gas involving oxidizing agent. - In particular, the cathode off-
gas supply conduit 25 is connected to thecylindrical portion 35c of thehousing 35 with respect of the inner peripheral surface thereof such that, as shown in Fig. 4B, a right end portion, which forms the outermost area to cause swirl flow, extends along a tangential line of the inner peripheral surface of thecylindrical portion 35c while a left end portion, which forms the innermost area to cause swirl flow, terminates in the inner peripheral surface of thecylindrical portion 35c at a position displaced rightward from the central axis CX. Further, as a result of such structure, thedischarge port 49 of the cathode off-gas supply conduit 25 penetrates through thecylindrical portion 35c of thehousing 35, and aboundary surface 49A between the cathode off-gas supply conduit 25 and the interior of thecylindrical portion 35c of thehousing 35 lies along a part of the inner peripheral surface of thecylindrical portion 35c. Also, such adischarge port 49 is located at a position closer to the introducingend wall 35a of thehousing 35 than thedistal end 39A of thenozzle 39 as viewed in Fig. 4A. With such a structure, as shown in Fig. 5, cathode off-gas ejecting from thedischarge port 49 can be supplied into thehousing 35 as swirl flow SWA, with no occurrence of undesired interference with swirl flow SW of anode off-gas, while swirling along the circumferential inner peripheral surface of thecylindrical portion 35c of thehousing 35. Also, a direction in which swirl flow SWA of cathode off-gas shown in Fig. 5 occurs is clockwise, that is, in the same direction as that of swirl flow SW of anode off-gas. - Here, when cathode off-gas is discharged into the
catalytic combustor 23, it is conceived that steam in cathode off-gas is condensed in the cathode off-gas supply conduit 25 to form liquid water which enters thehousing 35. - Such condensed water is subject to swirl flow SWA of cathode off-gas and is dispersed by a centrifugal force, as shown in Fig. 5, to be formed into water droplets W that deposit to the inner peripheral surface of the
cylindrical portion 35c of thehousing 35. With such a structure, this avoids condensed water from directly reaching thecatalyst 37 to preclude thecatalyst 37 from loosing an activity, thereby enabling anode off-gas to be reliably combusted. - Further, the
protrusion 47, which is formed on the inner peripheral wall of thecylindrical portion 35c of thehousing 35 in an annular configuration at the area near thecatalyst 37, blocks the flow of condensed water from traveling to thecatalyst 37, thereby condensed water to be reliably protected from depositing to thecatalyst 37. - Furthermore, like in the first embodiment, since swirl flow SW occurs in anode off-gas supplied from the
nozzle 39A of the anode off-gas supply conduit 21, condensed water in anode off-gas is dispersed onto the outer peripheral side within thehousing 35, thereby enabling condensed water from depositing to thecatalyst 37. - Incidentally, while the presently filed embodiment has been described in conjunction with the structure wherein the
nozzle 39A of the anode off-gas supply conduit 21 also forms swirl flow SW, it is, of course, to be noted that another alternative may be employed wherein such a structure can be omitted to allow only swirl flow SWA to occur in cathode off-gas, with anode off-gas being supplied to thehousing 35 without causing swirl flow SW. - Next, a catalytic combustor and a fuel cell system of a third embodiment according to the present invention are described below in detail with reference to Figs. 6A to 7. The presently filed embodiment mainly differs from the second embodiment in respect of a connecting structure of the anode of-
gas supply conduit 21 and the cathode of-gas supply conduit 25 with respect to thehousing 35 of thecatalytic combustor 23, and a main different point resides in that, in order for swirl flow to be generated not only in anode off-gas but also in cathode off-gas, the anode off-gas supply conduit 21 and the cathode off-gas supply conduit 25 are concentrically connected to thehousing 35, and the other structure is similar to the second embodiment. Thus, like component parts bear the same reference numerals as those of the first embodiment, with description being made in a suitably simplified form or omitted. - As shown in Figs. 6A and 6B, the connecting structure, in the presently filed embodiment, of the cathode off-
gas supply conduit 25 with respect to thehousing 35 is identical to that of the cathode off-gas supply conduit 25 in the second embodiment shown in Fig. 4. And, the anode off-gas supply conduit 21 is located inside such structured cathode off-gas supply conduit 25 and connected to thehousing 35 concentrically with the cathode off-gas supply conduit 25 along a central axis CX'. More particularly, anozzle 39B, forming a fuel supply port, of the anode off-gas supply conduit 21 is accommodated in the cathode off-gas supply conduit 25 so as to lie on the same plane as theboundary surface 49A of thedischarge port 49 of the cathode off-gas supply conduit 25 or to be located in a position proximity to theboundary surface 49A at an area outside thereof. Such a layout position of thenozzle 39B of the anode off-gas supply conduit 21 is determined so as to assume a position such that a direction in which anode off-gas is supplied into thecylindrical portion 35c is oriented in substantially the same direction as the direction in which cathode off-gas is supplied through thedischarge port 49 of the cathode off-gas supply conduit 25 whereby swirl flow is formed in anode off-gas per se without undesirably and adversely affecting swirl flow of cathode off-gas. - And, a direction in which anode off-gas is supplied through the
nozzle 39B of the anode off-gas supply conduit 21 is oriented in the same direction as the direction in which cathode off-gas is supplied through thedischarge port 49 of the cathode off-gas supply conduit 25 to allow anode off-gas to be supplied into thehousing 35 along the circular inner peripheral surface of thecylindrical portion 35c of thehousing 35 and mixed with cathode off-gas to form mixed gas with swirl flow SW swirling along the inner peripheral surface of thecylindrical portion 35c of thehousing 35 being formed. - Even with such a structure, since swirl flow can be generated in cathode off-gas inside the
cylindrical portion 35c of thehousing 35 of thecatalytic combustor 23 and also anode off-gas is supplied in the same direction as cathode off-gas, anode off-gas is similarly able to form swirl flow. That is, as shown in Fig. 7, swirl flows SW can be formed in cathode off-gas and anode off-gas and therefore condensed water contained in anode off-gas and cathode off-gas is dispersed in the inner peripheral surface of thecylindrical portion 35c of thehousing 35 due to centrifugal forces exerted by swirl flows SW with a resultant formation of water droplets W that can deposit to the inner peripheral surface of thecylindrical portion 35c. Such a structure enables condensed water to be blocked from directly getting thecatalyst 37 and to preclude thecatalyst 37 from being deteriorated in activity and thus, anode off-gas can be reliably combusted. - Incidentally, while the presently filed embodiment has been described with reference to the structure wherein the anode off-
gas supply conduit 21 is disposed inside the cathode off-gas supply conduit 25, the cathode off-gas supply conduit 25 may be disposed inside the anode off-gas supply conduit 21. - With the various embodiments according to the present invention set forth above, since an inner peripheral shape, in cross section, of the housing of the catalytic combustor, intersecting a direction in which mixed gas between exhaust fuel and exhaust air flows into the catalyst, is typically formed to have the substantially circular configuration to allow exhaust fuel and exhaust air to be supplied to the interior of the housing at the areas upstream of the catalyst of the catalytic combustor such that swirl flow occurs along the inner peripheral surface of the housing, condensed water involved in exhaust fuel and exhaust air can be dispersed toward the outer peripheral side of the housing to avoid condensed water from adhering to the catalyst for thereby precluding the catalyst from deteriorated in activity, thereby enabling mixed gas, especially exhaust fuel, expelled from the fuel cell to be reliably combusted.
- Although the invention has been described above by reference to certain embodiments of the invention, the invention is not limited to the embodiments described above. Modifications and variations of the embodiments described above will occur to those skilled in the art, in light of the teachings. The scope of the invention is defined with reference to the following claims.
Claims (20)
- A catalytic combustor (23) comprising:a housing (35) supplied with mixed gas including exhaust fuel gas from a fuel electrode (3) of a fuel cell (1) and exhaust oxidizer gas from an oxidizer electrode (5) of the fuel cell; anda catalyst (37) combusting the mixed gas,
- The catalytic combustor according to claim 1, wherein the inner peripheral surface is a cylindrical surface.
- The catalytic combustor according to claim 1, wherein supplying at least one of the exhaust fuel gas and the exhaust oxidizer gas into the housing while causing swirl flow (SW, SWA) to occur therein allows the swirl flow (SW) to occur in the mixed gas.
- The catalytic combustor according to claim 3, wherein an exhaust fuel supply port (39) supplying the exhaust fuel gas to the housing (35) is placed in opposition to the catalyst (37) and disposed along a central axis (CX) of the inner peripheral surface of the housing.
- The catalytic combustor according to claim 4, wherein the exhaust fuel supply port (39) causes swirl flow (SW) in the exhaust fuel gas.
- The catalytic combustor according to claim 3, wherein an exhaust oxidizer supply port (49) supplying the exhaust oxidizer gas to the housing (35) includes a portion connected to the inner peripheral surface of the housing in a tangential direction thereof.
- The catalytic combustor according to claim 6, wherein the exhaust oxidizer supply port (49) causes swirl flow (SWA) to occur in the exhaust oxidizer gas.
- The catalytic combustor according to claim 3, wherein an exhaust fuel supply port (39B) supplying the exhaust fuel gas to the housing (35) is disposed in an exhaust oxidizer supply port (49) supplying the exhaust oxidizer gas to the housing so as to allow the exhaust fuel gas to be supplied in a direction as same as that of the exhaust oxidizer gas.
- The catalytic combustor according to claim 1, wherein the inner peripheral surface of the housing (35) includes an annular protrusion (47) that protrudes inward from the inner peripheral surface at an area upstream of the catalyst (37).
- A fuel cell system (S) comprising:a fuel cell (1) having a fuel electrode (3) and an oxidizer electrode (5); anda catalytic combustor (23) provided with:a housing (35) supplied with mixed gas including exhaust fuel gas from a fuel electrode of a fuel cell and exhaust oxidizer gas from an oxidizer electrode of the fuel cell; anda catalyst (37) combusting the mixed gas,
- The fuel cell system according to claim 10, further comprising:a recirculation passage (17) supplying the exhaust fuel gas from the fuel electrode to the fuel electrode;an exhaust fuel gas supply passage (21) supplying the exhaust fuel gas from a midcourse of the recirculation passage to the catalytic combustor (23); anda valve (19) disposed in the recirculation passage and operative to be opened to supply the exhaust fuel gas to the catalytic combustor.
- The fuel cell system according to claim 10, wherein the inner peripheral surface is a cylindrical surface.
- The fuel cell system according to claim 10, wherein supplying at least one of the exhaust fuel gas and the exhaust oxidizer gas into the housing while causing swirl flow (SW, SWA) to occur therein allows the swirl flow (SW) to occur in the mixed gas.
- The fuel cell system according to claim 13, wherein an exhaust fuel supply port (39) supplying the exhaust fuel gas to the housing (35) is placed in opposition to the catalyst (37) and disposed along a central axis (CX) of the inner peripheral surface of the housing.
- The fuel cell system according to claim 14, wherein the exhaust fuel supply port (39) causes the swirl flow (SW) in the exhaust fuel gas.
- The fuel cell system according to claim 13, wherein an exhaust oxidizer supply port (49) supplying the exhaust oxidizer gas to the housing (35) includes a portion connected to the inner peripheral surface of the housing in a tangential direction thereof.
- The fuel cell system according to claim 16, wherein the exhaust oxidizer supply port (49) causes swirl flow (SWA) to occur in the exhaust oxidizer gas.
- The fuel cell system according to claim 13, wherein an exhaust fuel supply port (39B) supplying the exhaust fuel gas to the housing (35) is disposed in an exhaust oxidizer supply port (49) supplying the exhaust oxidizer gas to the housing so as to allow the exhaust fuel gas to be supplied in a direction as same as that of the exhaust oxidizer gas.
- The fuel cell system according to claim 10, wherein the inner peripheral surface of the housing (35) includes an annular protrusion (47) that protrudes inward from the inner peripheral surface at an area upstream of the catalyst (37).
- A method of supplying gas to a catalytic combustor (23) provided with a housing (35) supplied with mixed gas including exhaust fuel gas from a fuel electrode (3) of a fuel cell (1) and exhaust oxidizer gas from an oxidizer electrode (5) of the fuel cell, and a catalyst (37) combusting the mixed gas, wherein at an area upstream of the catalyst, an inner periphery surface of the housing has a continuous shape, the method comprising:supplying at least one of the exhaust fuel gas and the exhaust oxidizer gas to the housing so as to generate swirl flow (SW) to occur in the mixed gas so as to swirl along the inner peripheral surface.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002374440A JP2004207025A (en) | 2002-12-25 | 2002-12-25 | Catalytic combustor and fuel cell system |
JP2002374440 | 2002-12-25 |
Publications (1)
Publication Number | Publication Date |
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EP1458045A2 true EP1458045A2 (en) | 2004-09-15 |
Family
ID=32652677
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP03028645A Withdrawn EP1458045A2 (en) | 2002-12-25 | 2003-12-15 | Catalytic combustor and fuel cell system |
Country Status (3)
Country | Link |
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US (1) | US20040126724A1 (en) |
EP (1) | EP1458045A2 (en) |
JP (1) | JP2004207025A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2004105165A2 (en) * | 2003-05-21 | 2004-12-02 | Nissan Motor Co., Ltd. | Fuel cell arrangement |
DE102005059481B3 (en) * | 2005-12-07 | 2007-07-12 | DAS - Dünnschicht Anlagen Systeme GmbH | Reaction chamber wall cleaning device for use in solid state technology, has feeder with water nozzles, where water from nozzle is sprayed between burner and reaction chamber wall in specific interval |
CN111156532A (en) * | 2020-02-27 | 2020-05-15 | 四川恒泰环境技术有限责任公司 | VOCs processing method and device |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4784078B2 (en) * | 2004-11-26 | 2011-09-28 | 日産自動車株式会社 | Catalytic combustor |
GB0509163D0 (en) * | 2005-05-05 | 2005-06-15 | Boc Group Plc | Gas combustion apparatus |
JP2007042597A (en) * | 2005-07-01 | 2007-02-15 | Nissan Motor Co Ltd | Catalytic combustor |
KR100686714B1 (en) * | 2005-11-22 | 2007-02-26 | 대구도시가스 주식회사 | Heat recovery device for cogeneration fuel cell system |
WO2008091801A2 (en) * | 2007-01-22 | 2008-07-31 | Rolls-Royce Fuel Cell Systems Inc. | Multistage combustor and method for starting a fuel cell system |
CN102147111B (en) * | 2011-03-21 | 2012-06-06 | 重庆大学 | Grading catalytic combustion device capable of coupling strong and weak heat release |
US9422862B2 (en) * | 2012-02-27 | 2016-08-23 | Mitsubishi Hitachi Power Systems, Ltd. | Combined cycle power system including a fuel cell and a gas turbine |
US9190676B2 (en) * | 2012-09-28 | 2015-11-17 | Fuelcell Energy, Inc. | Flame stabilized mixer-eductor-oxidizer for high temperature fuel cells |
GB2621338A (en) * | 2022-08-08 | 2024-02-14 | Ceres Ip Co Ltd | Fuel cell system and method of operating the same |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR1094871A (en) * | 1959-01-22 | 1955-05-25 | Thomson Houston Comp Francaise | Improvements to injected fuel combustion devices |
US3635682A (en) * | 1969-06-13 | 1972-01-18 | United Aircraft Corp | Fuel cell reactor-burner assembly |
US4054418A (en) * | 1975-11-10 | 1977-10-18 | E. I. Du Pont De Nemours And Company | Catalytic abatement system |
DE2614673C3 (en) * | 1976-04-05 | 1981-06-25 | Siemens AG, 1000 Berlin und 8000 München | Starting device for a gap gas generator |
US4118171A (en) * | 1976-12-22 | 1978-10-03 | Engelhard Minerals & Chemicals Corporation | Method for effecting sustained combustion of carbonaceous fuel |
DE2836534C2 (en) * | 1978-08-21 | 1982-09-02 | Oertli AG Dübendorf, Dübendorf | Process for burning liquid fuel and burners for carrying out the process |
US4930454A (en) * | 1981-08-14 | 1990-06-05 | Dresser Industries, Inc. | Steam generating system |
EP0716263B1 (en) * | 1994-12-06 | 2002-10-09 | Matsushita Electric Industrial Co., Ltd. | Combustion apparatus |
US6835354B2 (en) * | 2000-04-05 | 2004-12-28 | Hyradix, Inc. | Integrated reactor |
US6596424B2 (en) * | 2001-03-30 | 2003-07-22 | General Motors Corporation | Apparatus for mixing fuel and an oxidant |
US6712603B2 (en) * | 2002-08-07 | 2004-03-30 | General Motors Corporation | Multiple port catalytic combustion device and method of operating same |
-
2002
- 2002-12-25 JP JP2002374440A patent/JP2004207025A/en active Pending
-
2003
- 2003-11-12 US US10/704,777 patent/US20040126724A1/en not_active Abandoned
- 2003-12-15 EP EP03028645A patent/EP1458045A2/en not_active Withdrawn
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2004105165A2 (en) * | 2003-05-21 | 2004-12-02 | Nissan Motor Co., Ltd. | Fuel cell arrangement |
WO2004105165A3 (en) * | 2003-05-21 | 2005-02-24 | Nissan Motor | Fuel cell arrangement |
DE102005059481B3 (en) * | 2005-12-07 | 2007-07-12 | DAS - Dünnschicht Anlagen Systeme GmbH | Reaction chamber wall cleaning device for use in solid state technology, has feeder with water nozzles, where water from nozzle is sprayed between burner and reaction chamber wall in specific interval |
CN111156532A (en) * | 2020-02-27 | 2020-05-15 | 四川恒泰环境技术有限责任公司 | VOCs processing method and device |
Also Published As
Publication number | Publication date |
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JP2004207025A (en) | 2004-07-22 |
US20040126724A1 (en) | 2004-07-01 |
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