JP2006331745A - Exhaust gas treatment device for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust gas treatment device for a fuel cell that can contribute to the improvement of efficiency in a fuel cell system by reducing pressure loss when introducing a diluent gas. <P>SOLUTION: The exhaust gas treatment device for a fuel cell is provided with a dilution container 51, an anode off-gas introduction path 52 for introducing an anode off-gas into the dilution container 51, a diluent gas path 57 in which the diluent gas circulates, and a diluent gas introducer 58 made to communicate with the diluent gas path 57 and introducing the diluent gas circulating in the diluent gas path 57 into the dilution container 51. The diluent gas introducer 58 is formed so that the circulation direction of the diluent gas to be introduced is coincident with that of the diluent gas flowing in the diluent gas path 52 on its upstream side. The diluent gas path 52 is formed so that the circulation direction of the diluent gas is changed at the downstream side of the diluent gas introducer 58. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an exhaust gas processing apparatus for diluting a gas discharged from a fuel cell.

  Some fuel cells mounted on fuel cell vehicles or the like obtain electric power by electrochemical reaction of reaction gases. As this type of fuel cell, an anode and a cathode are provided on both sides of a solid polymer electrolyte membrane, a fuel gas (eg, hydrogen gas) is supplied to the anode, and an oxidant gas (eg, air containing oxygen) is supplied to the cathode. In some cases, chemical energy related to the oxidation-reduction reaction of these reaction gases is directly extracted as electric energy.

  In this fuel cell, water is generated on the cathode side with power generation, and a part of this generated water permeates the solid polymer electrolyte membrane and enters the anode side. In addition, a small amount of nitrogen in the air supplied to the cathode permeates the solid polymer electrolyte membrane to the anode side and enters hydrogen gas. These impurities such as moisture and nitrogen on the anode side may make power generation of the fuel cell unstable.

In particular, in a circulation type fuel cell system in which unreacted hydrogen (anode offgas) discharged from the fuel cell is recycled to mix with fresh hydrogen gas and supplied to the fuel cell again in order to increase the fuel utilization rate, The impurity concentration on the anode side tends to increase gradually.
Therefore, in this type of fuel cell, the anode offgas containing the impurities is discharged by periodically opening the discharge valve from the anode offgas circulation path through which the anode offgas circulates, thereby reducing the impurity concentration in the anode offgas.

When the anode off-gas discharged from the anode off-gas circulation path is discharged to the outside (atmosphere), the anode off-gas is discharged with a dilution gas (for example, air as cathode off-gas discharged from the cathode) by an exhaust gas processing device. Diluted to reduce hydrogen concentration before discharging.
Patent Document 1 discloses an example of a conventional exhaust gas processing apparatus. In this exhaust gas processing apparatus, a branch introduction flow path branched from a cathode off gas flow path (oxygen off gas discharge flow path) is connected to a diluter, and the cathode off gas is introduced into the diluter through the branch introduction flow path. ing.
JP 2002-289237 A

By the way, in the prior art, in order to prevent the anode gas introduced into the diluter from being discharged from the branch introduction passage of the cathode off gas, a pressure loss portion is provided in the branch introduction passage. . As a result, a large pressure loss occurs when introducing the cathode off gas into the diluter, and as a result, the burden required for the compressor that supplies the cathode gas to the fuel cell is greatly increased. There is a problem of reducing the efficiency of the fuel cell system.
It is an object of the present invention to provide a fuel cell exhaust gas treatment device that can contribute to improving the efficiency of a fuel cell system by reducing pressure loss when introducing a diluent gas.

  The invention according to claim 1 is directed to a fuel cell exhaust gas processing apparatus that mixes and discharges an anode off-gas exhausted from an anode of a fuel cell with a diluent gas. An anode off-gas introduction path (for example, anode off-gas introduction pipe 52 in the embodiment) for introducing the anode off-gas into the dilution container, and a dilution gas path (for example, dilution gas pipe 57 in the embodiment) through which the dilution gas flows. ) And a dilution gas introduction part (for example, the dilution gas discharge hole 58 in the embodiment) for introducing the dilution gas flowing through the dilution gas path into the dilution container. The dilution gas introduction part is configured such that the flow direction of the dilution gas to be introduced coincides with the flow direction of the dilution gas flowing through the dilution gas path on the upstream side. The dilution gas passage is formed to change the flow direction of the dilution gas downstream of the dilution gas introduction part (for example, a step part 57c in the embodiment). To do.

  According to this invention, at least a part of the dilution gas flowing through the dilution gas passage passes through the dilution gas introduction portion formed so as to coincide with the flow direction by inertia. And when passing through the dilution gas introduction part, it is introduced into the dilution container without changing the flowing direction. Therefore, when introduced into the dilution container, loss of kinetic energy provided in the dilution gas can be suppressed, and this kinetic energy can be utilized to promote diffusion in the dilution container and mixing of the anode off gas. it can. In addition, since the pressure of the dilution gas discharged from the dilution gas introduction part can be secured above a certain level, the anode off-gas introduced into the dilution container can be prevented from flowing into the dilution gas introduction part. Therefore, when introducing the dilution gas into the dilution container, there is no need to form a pressure loss portion in the dilution gas introduction portion, thereby reducing the load required to distribute the dilution gas, This can contribute to improving the efficiency of the fuel cell system.

The invention according to claim 2 is the invention according to claim 1, wherein the dilution gas introduction portion is disposed in the dilution gas path so as to be perpendicular to the direction in which the dilution gas is introduced into the dilution container. It is the formed through-hole.
According to the present invention, the dilution gas introduction part can be formed simply by drilling the member communicated with the dilution gas path, so that the dilution gas introduction part can be formed easily and at low cost. In addition, since the through hole is formed perpendicular to the direction of introduction into the dilution container, energy loss of the dilution gas passing through the through hole can be minimized, and the dilution gas can be circulated. Therefore, the load required for this can be further reduced.

According to a third aspect of the present invention, there is provided the first or second aspect of the present invention, wherein the dilution gas path is provided with a compressor for sending the dilution gas.
According to the present invention, since the load required for the compressor to introduce the dilution gas into the dilution container can be suppressed, the size of the compressor can be reduced, and the degree of layout can be increased accordingly. it can.

According to the first aspect of the invention, the pressure loss when introducing the dilution gas can be reduced, which can contribute to improving the efficiency of the fuel cell system.
According to the invention which concerns on Claim 2, formation of a dilution gas introduction part can be performed simply and at low cost, and the load required in order to distribute | circulate dilution gas can further be reduced.
According to the invention which concerns on Claim 3, size reduction of a compressor can be achieved and the freedom degree of a layout can be raised by that much.

Hereinafter, an embodiment of an exhaust gas treatment apparatus for a fuel cell according to the present invention will be described with reference to the drawings of FIGS. 1 to 3. FIG. 1 is a schematic diagram of a fuel cell system provided with the exhaust gas treatment apparatus according to the present invention. It is a block diagram and is mounted on a fuel cell vehicle in this embodiment.
The fuel cell 1 is of a type in which a reaction gas is electrochemically reacted to obtain electric power. For example, the fuel cell 1 is formed by sandwiching a solid polymer electrolyte membrane 2 made of a solid polymer ion exchange membrane or the like between an anode 3 and a cathode 4 from both sides. A plurality of cells are stacked (only a single cell is shown in FIG. 1), hydrogen gas (reactive gas) is supplied as fuel gas to the anode 3, and oxygen (reactive gas) is used as the oxidant gas to the cathode 4. When the air containing oxygen is supplied, hydrogen ions generated by the catalytic reaction at the anode 3 pass through the solid polymer electrolyte membrane 2 to the cathode 4 and cause an electrochemical reaction with oxygen at the cathode 4 to generate electricity, Water is produced. Since part of the generated water generated on the cathode side permeates the solid polymer electrolyte membrane 2 and back diffuses to the anode side, the generated water also exists on the anode side.

  Air is pressurized to a predetermined pressure by a compressor 7 such as a supercharger (S / C), and supplied to the cathode 4 of the fuel cell 1 through an air supply path 8. After the air supplied to the fuel cell 1 is used for power generation, it is discharged from the fuel cell 1 together with the produced water on the cathode side into the air discharge passage 9 and introduced into the exhaust gas processing device 50 through the pressure control valve 10. . Hereinafter, the air supplied to the fuel cell 1 is distinguished as supply air, and the air discharged from the fuel cell 1 is distinguished as exhaust air (dilution gas).

  On the other hand, the hydrogen gas supplied from the hydrogen tank 15 flows through the hydrogen gas supply path 17, and is depressurized to a predetermined pressure by the regulator 16 on the way, controlled to a predetermined flow rate by the flow control valve 23, and passes through the ejector 19 to the fuel. Supplied to the anode 3 of the battery 1. The unreacted hydrogen gas that has not been consumed is discharged from the fuel cell 1 as an anode off-gas, sucked into the ejector 19 through the anode off-gas passage 18, and merged with fresh hydrogen gas supplied from the hydrogen tank 15. It is supplied again to the anode 3 of the fuel cell 1. That is, the anode offgas discharged from the fuel cell 1 circulates in the fuel cell 1 through the anode offgas passage 18 and the hydrogen gas supply passage 17 downstream of the ejector 19. In this embodiment, the hydrogen gas supply path 17 and the anode off-gas path 18 downstream from the ejector 19 constitute a fuel gas circulation path 20.

  An anode offgas discharge path 22 having a discharge valve 21 branches from the anode offgas path 18, and the anode offgas discharge path 22 is connected to the exhaust gas processing device 50. In the exhaust gas processing device 50, the anode off gas discharged from the anode off gas discharge path 22 is diluted by the exhaust air discharged from the air discharge path 9 and is discharged to the discharge portion via the mixed gas discharge path 30.

The electric power obtained by the power generation of the fuel cell 1 is supplied to a load such as a vehicle driving motor (not shown).
The rotational speed of the compressor 7, the opening degree of the pressure control valve 10 and the flow rate control valve 23, and the opening / closing of the discharge valve 21 are controlled by an electronic control unit (hereinafter abbreviated as ECU) 40.

In the fuel cell system configured as described above, when continuously operating, the concentration of impurities (water, nitrogen, etc.) in the hydrogen gas flowing through the fuel gas circulation path 20 increases as described above. The power generation of the battery 1 may become unstable.
Therefore, in this fuel cell system, when the ECU 40 determines that the fuel cell system has been continuously operated for a certain period of time, or when it is determined that the power generation stability of the fuel cell 1 has been reduced, there is an impurity emission request. In the hydrogen gas flowing through the anode 3 of the fuel cell 1, the discharge valve 21 is opened and the anode offgas containing impurities is discharged from the anode offgas passage 18 to the exhaust gas treatment device 50 through the anode offgas discharge passage 22. The impurity concentration of the fuel cell 1 is controlled to be a predetermined value or less, and the power generation of the fuel cell 1 is maintained in a stable state.

Next, the configuration of the exhaust gas treatment device 50 will be described in detail with reference to the drawings of FIGS.
The exhaust gas treatment device 50 includes a sealed cylindrical dilution container 51. The dilution container 51 is installed in the vehicle in a posture in which its axial center is substantially horizontal, and has an elliptical shape with the same cross-sectional shape orthogonal to the axial direction over the entire length in the axial direction. The major axis of the ellipse is arranged in the vertical direction.
In other words, the dilution container 51 has its axial center set in a substantially horizontal posture, and the cross-sectional shape orthogonal to the axial direction is a curve that is convex outward over the entire circumference of the closed cross-section. It is configured.

  An anode off-gas introduction pipe (anode off-gas introduction path) 52, which is disposed in a horizontal position slightly below the axis of the dilution container 51, passes through and is fixed to the end plate 51 a at one axial end side of the dilution container 51. Has been. An anode off gas discharge path 22 is connected to the base end of the anode off gas introduction pipe 52, and when the discharge valve 21 is opened, the anode off gas is introduced into the dilution container 51 from the anode off gas introduction pipe 52.

Further, inside the dilution container 51, a partition plate 53 is fixed in a substantially vertical posture in front of the tip of the anode off-gas introduction pipe 52 and substantially in the center of the dilution container 51 in the axial direction. The partition plate 53 has a shape in which an upper portion of the ellipse is cut out, and is fixed in close contact with the inner surface of the dilution container 51 except for the cutout portion 53a. The inside of the dilution container 51 is partitioned by the partition plate 53 into an upstream chamber 54 that communicates with the anode off-gas introduction pipe 52 and the dilution gas discharge hole 58 described later, and a downstream chamber 55 that communicates with the mixed gas discharge hole 61 described later. The upper side of 53 a is a communication gas path 56 that communicates the upstream chamber 54 and the downstream chamber 55.
The notch 53 a of the partition plate 53 is located sufficiently above the axis of the dilution container 51, and the partition plate 53 is also present on the axial extension of the anode offgas introduction pipe 52. Therefore, as shown in FIG. 3, most of the anode off gas released from the anode off gas introduction pipe 52 is released toward the partition plate 53.

  Furthermore, the dilution container 51 is provided with a dilution gas pipe (dilution gas passage) 57 that penetrates from the end plate 51a on one end side in the axial direction to the end plate 51b on the other end side. The upstream end 57a of the dilution gas pipe 57 is fixed along a predetermined position below the anode off-gas introduction pipe 52, and the downstream end 57b of the dilution gas pipe 57 is the lowermost part of the inner surface of the dilution container 51 ( It is fixed along the inner bottom. In this embodiment, the fixing position of the upstream end 57 a is set above the diameter of the dilution gas pipe 57 from the lowest part (inner bottom part) of the inner surface of the dilution container 51. The upstream end 57a is formed at a position near the end plate 51a in the dilution container 51, and a step 57c that changes the flow path is formed at the lowermost part (inner bottom) of the inner surface of the dilution container 51. The dilution gas pipe 57 also penetrates the partition plate 53 on the downstream side of the stepped portion 57c. The dilution gas pipe 57 is connected to the upstream end 57 a of the air discharge passage 9 and connected to the downstream end 57 b of the mixed gas discharge passage 30, and is discharged from the cathode of the fuel cell 1 to the air discharge passage 9. The exhausted air passes through the dilution gas pipe 57 and is discharged to the discharge portion through the mixed gas discharge path 30.

  A dilution gas discharge hole 58 is provided in the stepped portion 57 c of the dilution gas pipe 57. A part of the exhaust air (cathode off gas) flowing through the dilution gas pipe 57 is discharged from the dilution gas discharge hole 58 to the upstream chamber 54. The dilution gas discharge hole 58 is formed at the same position as the upstream end 57a when viewed from the axial direction of the dilution container 51 so as to be orthogonal to the axial direction. Thereby, the distribution direction of the exhaust air introduced into the dilution container 51 coincides with the distribution direction of the exhaust air flowing through the upstream end 57a.

  Further, in the dilution gas pipe 57, a drainage hole 60 is provided in a portion accommodated in each of the upstream chamber 54 and the downstream chamber 55 on the downstream side of the stepped portion 57 c. The liquid accumulated in the inner bottom portion of the upstream chamber 54 or the downstream chamber 55 is sucked into the dilution gas pipe 57 through these drain holes 60.

  Further, a portion of the dilution gas pipe 57 accommodated in the downstream chamber 55 is provided with a mixed gas discharge hole 61 on the downstream side of the drainage hole 60 and in the vicinity of the end plate 51b. The mixed gas discharge hole 61 opens at the top of the dilution gas pipe 57, and the gas in the downstream chamber 55 is discharged into the dilution gas pipe 57 through the mixed gas discharge hole 61.

Next, the operation of the exhaust gas processing device 50 will be described.
In this exhaust gas processing device, exhaust air discharged from the cathode 4 of the fuel cell 1 is always supplied from the compressor 7 to the cathode 4 of the fuel cell 1. Is introduced into the dilution gas pipe 57 of the exhaust gas processing device 50, and circulates through the dilution gas pipe 57 toward the mixed gas discharge path 30.

  At this time, at least a part of the exhaust air flowing through the upstream end 57a of the dilution gas pipe 57 passes through the dilution gas discharge hole 58 formed so as to coincide with the flow direction by inertia. Then, when passing through the dilution gas discharge hole 58, it is introduced into the upstream chamber 54 of the dilution container 51 without changing the flow direction. Therefore, when introduced into the dilution container 51, the loss of kinetic energy provided in the exhaust air is suppressed.

  On the other hand, as described above, the anode off-gas is discharged from the anode off-gas passage 18 when the exhaust valve 21 is opened when the ECU 40 determines that there is an impurity discharge request, and is discharged from the anode off-gas discharge passage 22. Are introduced into the anode off-gas introduction pipe 52, and discharged from the tip of the anode off-gas introduction pipe 52 into the upstream chamber 54.

  Therefore, when the anode off gas is not discharged from the anode off gas introduction pipe 52 to the upstream chamber 54 (that is, when the discharge valve 21 is closed), the pressure in the dilution container 51 hardly increases, but the discharge valve 21 Is opened and the anode off-gas is discharged from the anode off-gas introduction pipe 52 to the upstream chamber 54, the internal pressure of the dilution container 51 is rapidly increased. That is, there is a pressure change in the dilution container 51 in accordance with the anode off-gas discharge cycle.

  In the dilution container 51 in this embodiment, the cross-sectional shape orthogonal to the axial direction is configured by a curved line (ellipse) that protrudes outward along the entire circumference of the closed cross section. Both have an extremely high mechanical strength (pressure strength) against internal pressure and deformation (repetitive stress) caused by respiration of the dilution container, and can sufficiently withstand without any special reinforcing structure. And since the special reinforcement structure is unnecessary, manufacture of the exhaust gas processing apparatus 50 becomes easy.

  As shown in FIG. 3, the anode off-gas released from the anode off-gas introduction pipe 52 collides with the partition plate 53 to change the direction of the flow. It spreads almost entirely in the upstream chamber 54 at a flow rate. As a result, the anode off-gas is partially mixed with the exhaust air in the upstream chamber 54. As described above, when the exhaust air is introduced into the upstream chamber 54, the loss of kinetic energy provided in the exhaust air is suppressed, so that the kinetic energy is utilized to diffuse in the upstream chamber 54. And mixing of the anode off gas can be promoted. In addition, since the pressure of the exhaust air discharged from the dilution gas discharge hole 58 can be secured above a certain level, the anode off gas introduced into the dilution container 51 can be prevented from flowing into the dilution gas discharge hole 58. The other exhaust air that has not been discharged from the dilution gas discharge hole 58 flows through the dilution gas pipe 57 along the lowermost portion (inner bottom portion) of the inner surface of the dilution container 51 via the stepped portion 57c, and the downstream end It will head for the part 57b.

  As described above, the anode off-gas flows into the downstream chamber 55 through the communication gas path 56 and flows toward the mixed gas discharge hole 61 while being mixed with the discharge air. During this time, the mixed gas flowing in from the upstream chamber 54 and the gas in the downstream chamber 55 are further mixed. Then, the gas in the downstream chamber 55 is discharged from the mixed gas discharge hole 61 to the dilution gas pipe 57, mixed with the exhaust air flowing through the dilution gas pipe 57, further diluted and discharged.

  In this embodiment, by providing the partition plate 53, the moving distance of the gas in the dilution container 51 can be increased. Furthermore, the dilution gas discharge hole 58 is disposed in the vicinity of one end portion of the dilution container 51 in the axial direction, and the mixed gas discharge hole 61 is disposed in the vicinity of the other end portion of the dilution container 51 in the axial direction. The moving distance of the gas in 51 can be lengthened. As a result, the residence time of the gas in the dilution container 51 can be earned, and the time necessary for dilution can be secured, so that the anode off-gas can be reliably diluted.

Further, as described above, the anode off-gas introduced into the dilution container 51 contains water in a liquid or gas (vapor) state.
Further, in this embodiment, since the anode off gas is discharged from the anode off gas introduction pipe 52 toward the partition plate 53, the liquid contained in the anode off gas collides with and adheres to the partition plate 53, and the partition in the vertical posture is formed. It falls along the board 53. Further, the vapor in the anode off-gas collides with the partition plate 53 to promote condensation, and this condensate falls along the partition plate 53 in a vertical posture. That is, the partition plate 53 captures moisture in the anode off gas and makes it easier to gather below the dilution container 51.

Further, moisture (liquid and vapor) in the anode off-gas is also captured on the inner surface of the dilution container 51. The liquid adhering to the inner surface of the dilution container 51 and the condensate condensed on the inner surface of the dilution container 51 fall along the inner surface of the dilution container 51.
In this embodiment, the axial center of the dilution container 51 is installed in a substantially horizontal posture, and the shape of the cross section orthogonal to the axial direction is convex outward over the entire circumference of the closed cross section. The liquid can be reliably collected at the lowest vertical portion in the dilution container 51 (that is, the inner bottom of the dilution container 51), and no liquid pool is generated in other parts.
In particular, in this embodiment, the cross-sectional shape of the dilution container 51 is an ellipse, and the major axis of the ellipse is arranged in the vertical direction, so that the flow velocity of the liquid flowing down along the inner surface of the dilution container 51 can be increased. As a result, the liquid can be quickly collected in the lowermost part (that is, the inner bottom part) of the dilution container 51.

The liquid collected in the inner bottom portion of the dilution container 51 in this manner is sucked into the dilution gas pipe 57 from the drainage hole 60 and discharged to the mixed gas discharge path 30 together with the mixed gas.
In this embodiment, since the drainage hole 60 is provided in the lower half of the dilution gas pipe 57 and close to the inner bottom of the dilution container, the liquid accumulated at the bottom of the dilution container 51 can be easily discharged. Since the liquid remaining in the dilution container 51 without being discharged can be reduced, the drainage performance is improved.

Further, in this embodiment, since the dilution gas discharge hole 58, the mixed gas discharge hole 61, and the drainage hole 60 are all provided directly in the dilution gas pipe 57, the structure of the exhaust gas processing apparatus is simplified.
And in this Example, the load required in order to distribute | circulate exhaust air can be reduced by introduce | transducing the exhaust air which is dilution gas into the dilution container 51, without forming a pressure loss part. Therefore, since the load required for the compressor 7 to introduce the exhaust air into the dilution container 51 can be suppressed, it is possible to contribute to improving the efficiency of the fuel cell system.

In addition, since the exhaust air can be introduced into the dilution container 51 simply by making the dilution gas discharge hole 58 in the dilution gas pipe 57, the exhaust air can be introduced easily and at low cost. In addition, since the dilution gas discharge hole 58 is formed perpendicular to the introduction direction to the dilution container 51, the energy loss of the exhaust air passing through the dilution gas discharge hole 58 can be minimized, The load required to distribute this exhaust air can be further reduced.
Furthermore, since the size of the compressor 7 can be reduced by suppressing the load required for the compressor 7, the degree of freedom in layout can be increased.

[Other Examples]
The present invention is not limited to the embodiment described above. Hereinafter, modified examples of the present invention will be described with reference to FIGS. 4 and 5. In addition, about the structure similar to the Example mentioned above, the same number is attached | subjected and the description is abbreviate | omitted suitably.
FIG. 4 is a sectional view corresponding to FIG. 3, showing a modified embodiment of the exhaust gas treatment apparatus of the present invention. As shown in the figure, it is inclined at a predetermined angle with respect to the axis of the dilution vessel 51 so that the end surface constituting the stepped portion 57c ′ faces upward, and a dilution gas discharge hole 58 ′ is formed on this end surface. ing. Therefore, most of the exhausted air discharged from the dilution gas discharge hole 58 ′ is inclined upward along the center line of the dilution gas discharge hole 58 ′. Since the loss of kinetic energy of the exhaust gas discharged from the dilution gas discharge hole 58 ′ can be reduced, it is not necessary to form a pressure loss portion, and the same effect as the above-described embodiment can be obtained. Here, the predetermined angle is preferably set to 45 degrees or more.

  In the partition plate 53, the inclination angle of the end surface of the step portion 53 is such that the extension line of the axial center of the anode off-gas introduction pipe 52 and the extension line of the axial center of the dilution gas discharge hole 58 ′ substantially coincide with each other. Is preferable in that the mixing of the dilution gas and the anode off-gas can be promoted.

FIG. 5 is a schematic plan view showing another modified embodiment of the exhaust gas processing apparatus of the present invention. As shown in the figure, the upstream end 57 a is disposed at the lowermost part (inner bottom) of the inner surface of the dilution container 51. The upstream end 57 a is connected to detours 57 c ″ and 57 c ″ that bypass both side surfaces of the dilution container 51 before the end plate 51 a of the dilution container 51. On the other hand, the end plate 51a of the dilution container 51 is formed with a dilution gas discharge hole 58 '' at a portion facing the upstream end 57a.
The downstream end 57 b is connected to detours 57 c ″ and 57 c ″ that bypass both side surfaces of the dilution container 51 before the end plate 51 b of the dilution container 51. On the other hand, the end plate 51b of the dilution container 51 is formed with a mixed gas discharge hole 61 '' at a portion facing the downstream end 57b. In the figure, the anode off-gas introduction pipe 52 and the like are not shown.

  With this configuration, the exhaust air discharged from the dilution gas discharge hole 58 ″ is introduced into the upstream chamber 54 of the dilution container 51 without changing the flow direction to the upstream end 57 a. Therefore, when introduced into the dilution container 51, the loss of kinetic energy provided in the exhaust air is suppressed, and the same effect as the above-described embodiment can be achieved.

In addition to the above-described modifications, various modes are possible. For example, in the above-described embodiment, the dilution container has an elliptical cross section, but may be circular.
It is also possible to provide these holes in a branch pipe branched from the dilution gas path without providing the dilution gas discharge hole, the mixed gas discharge hole and the drainage hole directly in the dilution gas path.
In the embodiment described above, exhaust air (cathode off-gas) discharged from the cathode of the fuel cell is used as the dilution gas, but the dilution gas is not limited to this.
In the present embodiment, only one partition plate is provided, but a plurality of partition plates may be provided, for example, alternately arranged. In this case, some of the plurality of partition plates form an upstream chamber and a downstream chamber, and a location where the upstream chamber and the downstream chamber communicate with each other is a communication gas path.
In this embodiment, the partition plate is fixed in close contact with the inner surface of the dilution container except for the notch, but a slit may be provided at the lowermost portion of the partition plate. In this way, since the liquid inside the dilution container can move through the partition plate, for example, even when the drainage hole is installed only in either the upstream chamber or the downstream chamber, the drainage hole However, it is preferable because drainage can be performed at a location that is not installed.
In addition, the communication gas path is a notch in the above-described embodiment, but may be formed by piping.
In the above-described embodiment, the partition plate is provided inside the dilution container. However, the present invention can be realized without the partition plate.

It is a schematic block diagram of the fuel cell system provided with the exhaust gas processing apparatus which concerns on this invention. It is a perspective view of the exhaust gas processing apparatus in an Example. It is sectional drawing of the said exhaust gas processing apparatus. It is sectional drawing equivalent to FIG. 3 which shows the modified Example of the exhaust gas processing apparatus of this invention. It is a schematic plan view which shows the other modified example of the exhaust gas processing apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fuel cell 3 ... Anode 50 ... Exhaust gas processing apparatus 51 ... Dilution container 52 ... Anode offgas introduction pipe (anode offgas introduction path)
57 ... Dilution gas pipe (dilution gas passage)
57c ... Step part 58 ... Dilution gas discharge hole (dilution gas introduction part)

Claims (3)

In an exhaust gas treatment apparatus for a fuel cell that mixes and discharges an anode off-gas discharged from the anode of the fuel cell with a diluent gas,
A dilution container;
An anode offgas introduction path for introducing the anode offgas into the dilution container;
A dilution gas passage through which the dilution gas flows;
A dilution gas introduction part that communicates with the dilution gas path and introduces the dilution gas flowing through the dilution gas path into the dilution container; and
The dilution gas introduction part is formed so that the flow direction of the dilution gas to be introduced coincides with the flow direction of the dilution gas flowing through the dilution gas path on the upstream side thereof,
The exhaust gas processing apparatus for a fuel cell, wherein the dilution gas path is formed to change a flow direction of the dilution gas downstream of the dilution gas introduction portion. The dilution gas introduction part is
2. The exhaust gas processing apparatus for a fuel cell according to claim 1, wherein the exhaust gas processing apparatus is a through-hole formed in the dilution gas passage so as to be perpendicular to a direction in which the dilution gas is introduced into the dilution container. 3. The exhaust gas processing apparatus for a fuel cell according to claim 1, wherein the dilution gas passage is provided with a compressor that delivers the dilution gas. 4.

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