JP2010186730A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To uniformly and reliably distribute and supply reactant gas to each power generation cell in a fuel cell stack, and to prevent dew condensation water from being introduced into the fuel cell stack. <P>SOLUTION: The fuel cell system 10 includes a passage block 90 interposed between the fuel cell stack 14 and an ejector 50. A bending/connecting passage 120, which bends twice by substantially 90 degrees, is provided in the passage block 90 having an entrance 120a allowing the insertion of a diffuser 100 and an exit 120b communicating with a fuel gas supply-communicating hole 76a. The inner wall surface 126 is provided on the front side of a jetting path 116 of the diffuser 100, and the jetting path 116 and the fuel gas supply-communicating hole 76a are disposed to be mutually shifted in the laminating direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention provides a fuel cell stack in which a plurality of power generation cells are stacked, and an ejector that introduces a reaction gas into the fuel cell stack and returns spent reaction gas discharged from the fuel cell stack to the fuel cell stack. And a fuel cell system.

  For example, in a polymer electrolyte fuel cell, an electrolyte membrane / electrode structure (MEA) in which an anode side electrode and a cathode side electrode are disposed on both sides of an electrolyte membrane made of a polymer ion exchange membrane is sandwiched by separators. It has a power generation cell. This type of fuel cell is normally used as a fuel cell stack by stacking a predetermined number of power generation cells.

  By the way, in the fuel cell, fuel gas such as hydrogen gas is supplied to the anode side electrode, and fuel off-gas containing unreacted fuel gas that is not used for power generation is discharged from the fuel cell. Therefore, in order to make effective use of the fuel gas in consideration of economy, the fuel off gas is supplied again to the anode side electrode as the fuel gas.

  For example, in the fuel cell system disclosed in Patent Document 1, as shown in FIG. 12, a hydrogen supply path for supplying hydrogen from a hydrogen supply device 1 to a fuel cell 2 (a stack of a plurality of power generation cells 2a). 3, the off gas discharged from the fuel cell 2 joins the hydrogen supply path 3 and is recirculated to the fuel cell 2, the off gas is circulated to the off gas circulation path 4, and the off gas The amount of circulation is controllable, and an ejector pump 5 that mixes off-gas with main supply hydrogen and a pressure sensor 6 that detects the discharge pressure of the ejector pump 5 are provided.

JP 2004-95528 A

  By the way, when the ejector pump 5 is disposed in the vicinity of the fuel cell 2, hydrogen is discharged from the ejector pump 5 into the hydrogen supply communication hole of the fuel cell 2 at a high pressure. The static pressure distribution tends to occur. As a result, in the fuel cell 2, hydrogen is not sufficiently supplied to the power generation cell 2a located particularly on the hydrogen inlet side, and there is a problem that power generation performance is deteriorated.

  Further, the off gas contains water generated by the power generation reaction of the fuel cell 2, and the water vapor is likely to be condensed due to the condensation of the water vapor due to the temperature drop. When the water droplets are introduced into the fuel cell 2, there is a problem that it is difficult to stably maintain the power generation performance of the fuel cell 2. Moreover, since water vapor circulates in the off-gas circulation path 4 along with the flow of hydrogen, there is a problem that it is impossible to prevent the dew condensation from entering the fuel cell 2.

  The present invention solves this type of problem, and distributes and supplies reaction gas uniformly and reliably to each power generation cell stacked in the fuel cell stack, and condensed water is contained in the fuel cell stack. An object of the present invention is to provide a fuel cell system capable of preventing the introduction as much as possible.

  The present invention provides a reactive gas in which a plurality of power generation cells are stacked in a horizontal direction, an end plate is disposed at an end in the stacking direction, and at least a reaction gas that is a fuel gas or an oxidant gas is supplied along the stacking direction. A fuel cell stack provided with a supply communication hole, and a spent reaction gas that is attached to the end plate, introduces the reaction gas into the reaction gas supply communication hole from a reaction gas outlet, and is discharged from the fuel cell stack The present invention relates to a fuel cell system provided with an ejector that returns the gas to the reactive gas outlet for mixing with the unused reactive gas.

  In this fuel cell system, the reaction gas outlet of the ejector and the reaction gas supply communication hole of the end plate are arranged so as to be shifted from each other with respect to the stacking direction.

  Moreover, it is preferable that the reaction gas ejection port of the ejector is disposed below the reaction gas supply communication hole of the end plate.

  Furthermore, it is preferable that a water discharge port is provided below the tip of the reaction gas outlet of the ejector.

  Furthermore, an inner wall surface for forming a flow path communicating with the reaction gas supply communication hole of the end plate in the upward direction is disposed in front of the reaction gas ejection port of the ejector, and is orthogonal to the reaction gas ejection direction. It is preferable to extend in the vertical direction.

  Moreover, it is preferable that the inner wall surface is provided with a protrusion that is located above the reactive gas outlet and protrudes into the flow path from the end plate side.

  Furthermore, it is preferable that a concave portion is formed in the inner wall surface in front of the reaction gas outlet of the ejector.

  Furthermore, a flow path block is interposed between the end plate and the ejector, and the flow path block has an inlet communicating with the reactive gas ejection port and an outlet communicating with the reactive gas supply communication hole. It is preferable to provide a bent connection channel.

  Further, the end plate is preferably provided with a bent connection channel having an inlet communicating with the reactive gas ejection port and an outlet communicating with the reactive gas supply communication hole.

  Furthermore, it is preferable that a resin joint member for mounting the ejector is connected to the end plate.

  Furthermore, in the fuel cell system according to the present invention, a bent connection channel that connects the reaction gas outlet of the ejector and the reaction gas supply communication hole of the end plate is provided, and the bent connection channel is formed in a V shape downward. It has a bent part that bends.

  In addition, a flow path block is interposed between the end plate and the ejector, and the flow path block has a bent portion having an inlet communicating with the reactive gas ejection port and an outlet communicating with the reactive gas supply communication hole. It is preferable to provide a connection channel.

  According to the present invention, when the reactive gas is injected from the reactive gas outlet of the ejector into the reactive gas supply passage of the end plate, the relative displacement between the reactive gas outlet and the reactive gas supply passage is caused. The flow rate of the reaction gas is reduced, and moisture in the reaction gas is removed as condensed water.

  For this reason, reducing the flow velocity of the reaction gas improves the static pressure distribution in the reaction gas supply passage, while preventing the introduction of condensed water into the fuel cell stack as much as possible. it can. This makes it possible to uniformly and reliably distribute and supply the reaction gas to the power generation cells stacked in the fuel cell stack, and to stably maintain the power generation performance of the fuel cell stack.

  Further, according to the present invention, the bent connection channel that connects the reaction gas ejection port of the ejector and the reaction gas supply communication hole of the end plate has a bent portion bent downward in a V shape. Therefore, the reaction gas is rectified at the bent portion of the bent connection flow path, and condensed water is removed. For this reason, it is possible to distribute and supply the reaction gas uniformly and reliably to each power generation cell stacked in the fuel cell stack and to stably maintain the power generation performance of the fuel cell stack.

1 is a schematic configuration diagram of a fuel cell system according to a first embodiment of the present invention. It is a disassembled perspective explanatory drawing of the electric power generation cell which comprises the said fuel cell stack. It is principal part sectional drawing of the said fuel cell system. It is a schematic block diagram of the fuel cell system which concerns on the 2nd Embodiment of this invention. It is principal part sectional drawing of the said fuel cell system. It is principal part sectional explanatory drawing of the fuel cell system which concerns on the 3rd Embodiment of this invention. It is principal part sectional explanatory drawing of the fuel cell system which concerns on the 4th Embodiment of this invention. It is principal part sectional explanatory drawing of the fuel cell system which concerns on the 5th Embodiment of this invention. It is principal part sectional explanatory drawing of the fuel cell system which concerns on the 6th Embodiment of this invention. It is a schematic block diagram of the fuel cell system which concerns on the 7th Embodiment of this invention. It is principal part cross-sectional explanatory drawing of the fuel cell system which concerns on the 8th Embodiment of this invention. 2 is an explanatory diagram of a fuel cell system disclosed in Patent Document 1. FIG.

  FIG. 1 is a schematic configuration diagram of a fuel cell system 10 according to a first embodiment of the present invention.

  The fuel cell system 10 is mounted on a fuel cell vehicle (not shown). The fuel cell stack 14, a cooling medium supply mechanism 16 for supplying a cooling medium to the fuel cell stack 14, and the fuel cell stack 14 are oxidized. An oxidant gas supply mechanism 18 for supplying an agent gas (reactive gas) and a fuel gas supply mechanism 20 for supplying a fuel gas (reactive gas) to the fuel cell stack 14 are provided.

  The cooling medium supply mechanism 16 includes a radiator 24. A cooling medium supply pipe 28 and a cooling medium discharge pipe 30 are connected to the radiator 24 via a refrigerant pump 26.

  The oxidant gas supply mechanism 18 includes an air pump 32 disposed close to the refrigerant pump 26. An air supply pipe 34 having one end connected to the air pump 32 is connected to the humidifier 36, and the fuel cell stack 14 is connected to the humidifier 36 via a humidified air supply pipe 38. Is done. The fuel cell stack 14 and the humidifier 36 are connected to an off-gas supply pipe 40 for supplying a used oxidant gas (hereinafter referred to as off-gas) as a humidified fluid. In the humidifier 36, a back pressure valve 42 is disposed on the discharge side of the off gas supplied through the off gas supply pipe 40.

  The fuel gas supply mechanism 20 includes a fuel gas tank 44 in which hydrogen gas is stored as fuel gas. One end of a fuel gas pipe 45 is connected to the fuel gas tank 44, and the fuel gas pipe 45 is connected to the fuel cell stack 14 via a shut-off valve 46, a regulator 48 and an ejector 50.

  An exhaust fuel gas pipe 52 through which used fuel gas is discharged is connected to the fuel cell stack 14. The exhaust fuel gas pipe 52 is connected to the ejector 50 through a return pipe 54 and partly communicates with a dilution box 58 through a purge valve 56. For example, used oxidant gas discharged from the fuel cell stack 14 is introduced into the dilution box 58 as dilution air.

  In the fuel cell stack 14, a plurality of power generation cells 60 are stacked in the horizontal direction (the direction of arrow A in FIG. 2), and at both ends in the stacking direction, although not shown, end plates are connected via terminal plates and insulating plates. 62a and 62b are disposed (see FIG. 1). The fuel cell stack 14 includes, for example, a casing (not shown) having end plates 62a and 62b as end plates, or tie rods (not shown) that fasten the end plates 62a and 62b.

  Power extraction terminals 63a and 63b are provided on the terminal plate, and the power extraction terminals 63a and 63b protrude outward from the end plates 62a and 62b in the stacking direction. The electric power takeout terminals 63a and 63b are connected to a traveling motor and auxiliary equipment (not shown).

  As shown in FIG. 2, each power generation cell 60 includes an electrolyte membrane / electrode structure 66 and first and second separators 68 and 70 that sandwich the electrolyte membrane / electrode structure 66, and has a vertically long configuration. Is done. In addition, the 1st and 2nd separators 68 and 70 are comprised with a carbon separator or a metal separator.

  One end edge (upper end edge) of the power generation cell 60 in the long side direction (arrow C direction) communicates with each other in the arrow A direction to supply an oxidant gas, for example, an oxygen-containing gas. A supply communication hole (reaction gas supply communication hole) 72a and a fuel gas supply communication hole (reaction gas supply communication hole) 76a for supplying a fuel gas, for example, a hydrogen-containing gas, are provided.

  The other end edge (lower end edge) in the long side direction of the power generation cell 60 communicates with each other in the direction of the arrow A, and discharges the oxidant gas discharge communication hole 72b for discharging the oxidant gas and the fuel gas. A fuel gas discharge communication hole 76b is provided.

  A cooling medium supply communication hole 74a for supplying a cooling medium is provided at one end edge of the power generation cell 60 in the short side direction (arrow B direction), and the other end edge of the power generation cell 60 in the short side direction. Is provided with a cooling medium discharge communication hole 74b for discharging the cooling medium. The cooling medium supply communication hole 74a and the cooling medium discharge communication hole 74b are set in a vertically long shape.

  The electrolyte membrane / electrode structure 66 includes, for example, a solid polymer electrolyte membrane 78 in which a thin film of perfluorosulfonic acid is impregnated with water, and an anode side electrode 80 and a cathode side electrode 82 that sandwich the solid polymer electrolyte membrane 78. With.

  A fuel gas flow path 84 that connects the fuel gas supply communication hole 76 a and the fuel gas discharge communication hole 76 b is formed on the surface 68 a of the first separator 68 facing the electrolyte membrane / electrode structure 66. The fuel gas channel 84 is constituted by, for example, a groove extending in the direction of arrow C. A cooling medium flow path 86 that connects the cooling medium supply communication hole 74 a and the cooling medium discharge communication hole 74 b is formed on the surface 68 b opposite to the surface 68 a of the first separator 68. The cooling medium flow path 86 is constituted by a groove portion extending in the arrow B direction.

  The surface 70a of the second separator 70 facing the electrolyte membrane / electrode structure 66 is provided with, for example, an oxidant gas flow path 88 formed of a groove extending in the direction of arrow C. The oxidant gas supply communication hole 72a and the oxidant gas discharge communication hole 72b communicate with each other. A cooling medium flow path 86 is integrally formed on the surface 70b opposite to the surface 70a of the second separator 70 so as to overlap the surface 68b of the first separator 68. Although not shown, the first and second separators 68 and 70 are provided with seal members as necessary.

  As shown in FIG. 3, the ejector 50 is attached to the end plate 62b via a flow path block 90 that is a manifold member. The ejector 50 includes a cylindrical main body 94, and the main body 94 accommodates a nozzle 98 and a diffuser 100. An off gas passage 104 is formed in the main body portion 94. The nozzle 98 is provided with a fuel gas passage 106 communicating with the fuel gas pipe 45, and this fuel gas passage 106 is opened into the diffuser 100 from an injection port 110 provided at the tip of the nozzle 98.

  The off gas passage 104 communicates with the return pipe 54 and also communicates with the suction chamber 114 through a hole 112 formed on the outer periphery of the diffuser 100. The suction chamber 114 communicates with an injection passage (reactive gas outlet) 116 that is reduced in diameter toward the distal end side and then continuously increases in diameter toward the downstream in the flow direction.

  The tip of the diffuser 100 protrudes from the end of the main body 94 and is inserted into the inlet 120 a of the bent connection channel 120 provided in the channel block 90. The bent connection flow path 120 is bent twice by approximately 90 ° in the horizontal direction, and the outlet 120b communicates with the fuel gas supply communication hole 76a of the end plate 62b. Seal members 124a and 124b are interposed between the tip of the diffuser 100 and the inlet 120a, and between the outlet 120b and the fuel gas supply communication hole 76a of the end plate 62b, respectively.

  The injection passage 116 of the ejector 50 communicates with the inlet 120 a of the bent connection channel 120, while the fuel gas supply communication hole 76 a of the end plate 62 b communicates with the outlet 120 b of the bent connection channel 120. That is, the injection passage 116 of the ejector 50 and the fuel gas supply communication hole 76a of the end plate 62b are arranged so as to be shifted from each other with respect to the stacking direction (arrow A direction).

  The operation of the fuel cell system 10 configured as described above will be described below.

  First, as shown in FIG. 1, the air pump 32 constituting the oxidant gas supply mechanism 18 is driven, and external air that is an oxidant gas is sucked and introduced into the air supply pipe 34. The air is introduced into the humidifier 36 from the air supply pipe 34 and then supplied to the humidified air supply pipe 38.

  At that time, as will be described later, off-gas which is an oxidant gas used for the reaction is supplied to the off-gas supply pipe 40. For this reason, moisture contained in the off-gas moves to the air before use, and the air before use is humidified. The humidified air is supplied from the humidified air supply pipe 38 to the oxidant gas supply communication hole 72a in the fuel cell stack 14 through the end plate 62b.

  On the other hand, in the fuel gas supply mechanism 20, after the shutoff valve 46 is opened, the fuel gas (hydrogen gas) in the fuel gas tank 44 is stepped down by the regulator 48, and then the fuel cell stack passes from the ejector 50 through the end plate 62b. 14 is introduced into the fuel gas supply communication hole 76a.

  Further, in the cooling medium supply mechanism 16, under the action of the refrigerant pump 26, the cooling medium is introduced from the cooling medium supply pipe 28 through the end plate 62 a to the cooling medium supply communication hole 74 a in the fuel cell stack 14.

  As shown in FIG. 2, the air supplied to each power generation cell 60 in the fuel cell stack 14 is introduced into the oxidant gas flow path 88 of the second separator 70 from the oxidant gas supply communication hole 72a, and the electrolyte membrane / It moves along the cathode side electrode 82 of the electrode structure 66. On the other hand, the fuel gas is introduced into the fuel gas flow path 84 of the first separator 68 from the fuel gas supply communication hole 76 a and moves along the anode side electrode 80 of the electrolyte membrane / electrode structure 66.

  Therefore, in each electrolyte membrane / electrode structure 66, the oxygen in the air supplied to the cathode side electrode 82 and the fuel gas (hydrogen) supplied to the anode side electrode 80 undergo an electrochemical reaction in the electrode catalyst layer. To generate electricity.

  Next, the air consumed by being supplied to the cathode side electrode 82 flows along the oxidant gas discharge communication hole 72b, and is then discharged from the end plate 62b to the off gas supply pipe 40 as an off gas (see FIG. 1).

  Similarly, the fuel gas consumed by being supplied to the anode side electrode 80 is discharged and flows into the fuel gas discharge communication hole 76b, and is discharged from the end plate 62b to the discharged fuel gas pipe 52 as the discharged fuel gas (see FIG. 1). A part of the discharged fuel gas discharged to the discharged fuel gas pipe 52 passes through the return pipe 54 and is mixed into new fuel gas under the suction action of the ejector 50 and is supplied into the fuel cell stack 14. The remaining exhausted fuel gas is introduced into the dilution box 58 under the action of opening the purge valve 56.

  As shown in FIG. 2, the cooling medium is introduced into the cooling medium flow path 86 between the first and second separators 68 and 70 from the cooling medium supply communication hole 74 a and then flows along the arrow B direction. . The cooling medium cools the electrolyte membrane / electrode structure 66, moves through the cooling medium discharge communication hole 74 b, and is discharged from the end plate 62 a to the cooling medium discharge pipe 30. As shown in FIG. 1, the cooling medium is cooled by a radiator 24 and then supplied to the fuel cell stack 14 from a cooling medium supply pipe 28 under the action of a refrigerant pump 26.

  In this case, in the first embodiment, as shown in FIG. 3, the fuel gas supplied from the fuel gas pipe 45 to the fuel gas passage 106 of the nozzle 98 is supplied from the injection port 110 provided at the tip of the nozzle 98. It is injected into the diffuser 100. For this reason, a negative pressure is generated in the suction chamber 114, and the exhaust fuel gas is sucked into the suction chamber 114 from the return pipe 54 through the off gas passage 104.

  Accordingly, the discharged fuel gas is mixed with the fuel gas injected from the nozzle 98, and the mixed fuel gas is discharged from the injection passage 116 of the diffuser 100 toward the bent connection passage 120 of the passage block 90.

  At that time, the bent connection channel 120 is bent twice by approximately 90 ° in the horizontal direction. Thus, the fuel gas discharged to the inlet 120a is supplied to the fuel gas supply communication hole 76a of the end plate 62b from the outlet 120b after the flow velocity is reduced by the inner wall surface 126 constituting the bent portion of the bent connection channel 120. The In addition, when the fuel gas is blown onto the inner wall surface 126, the moisture in the fuel gas is removed as condensed water.

  For this reason, the flow rate of the fuel gas is reduced to improve the static pressure distribution in the fuel gas supply communication hole 76a, while preventing the introduction of condensed water into the fuel cell stack 14 as much as possible. Can do. In particular, the fuel gas can be surely distributed and supplied to the power generation cell 60 on the ejector 50 side where the fuel gas hardly enters.

  Therefore, in the first embodiment, the fuel gas is distributed and supplied to each power generation cell 60 stacked in the fuel cell stack 14 uniformly and reliably, and the power generation performance of the fuel cell stack 14 is stably provided. The effect that it becomes possible to maintain is acquired.

  In the first embodiment, the fuel gas circulated and supplied to the fuel cell stack 14 as the reaction gas has been described. However, the present invention is not limited to this, and the oxidizing gas is used as the reaction gas. The present invention can also be applied to the case where the fuel cell stack 14 is circulated and supplied. It is particularly suitable when pure oxygen is used as the oxidant gas. The same applies to the second and subsequent embodiments described below.

  Furthermore, in the first embodiment, the bent connecting flow path 120 is bent twice by approximately 90 ° in the horizontal direction, but instead, the inlet 120a is located above and the outlet 120b is located below. Further, it may be configured to be bent twice by approximately 90 ° in the vertical direction.

  FIG. 4 is a schematic configuration diagram of a fuel cell system 140 according to the second embodiment of the present invention. The same components as those of the fuel cell system 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. Similarly, in the third and subsequent embodiments described below, detailed description thereof is omitted.

  A gas-liquid separator 142 communicates with the fuel cell stack 14 through a fuel gas discharge communication hole 76b, and a drain channel 146 connected to the channel block 144 is connected to the gas-liquid separator 142. .

  As shown in FIG. 5, the flow path block 144 is interposed between the end plate 62 b and the ejector 50 and is provided with a bent connection flow path 148. The distal end of the diffuser 100 is inserted into the inlet 148a of the bent connection channel 148, and the outlet 148b of the bent connection channel 148 communicates with the fuel gas supply communication hole 76a. The inlet 148a is disposed below the outlet 148b, and the injection passage 116 is disposed below the fuel gas supply communication hole 76a.

  Inside the flow path block 144, an inner wall surface 150 for forming a flow path that is located in front of the injection passage 116 and communicates with the fuel gas supply communication hole 76 a in the upward direction is provided as fuel from the injection passage 116. It is orthogonal to the gas ejection direction and extends in the vertical direction. A water discharge port 152 is provided below the tip of the injection passage 116, and the water discharge port 152 communicates with the drain channel 146.

  In the second embodiment configured as described above, as shown in FIG. 5, the bent connection channel 148 has an inlet 148 a disposed below the outlet 148 b and is bent approximately 90 ° vertically upward. is doing. For this reason, the fuel gas discharged from the injection passage 116 of the diffuser 100 to the inlet 148a of the bent connection channel 148 is supplied from the outlet 148b to the fuel gas supply passage 76a after the flow velocity is reduced by the inner wall surface 150.

  Therefore, the flow rate of the fuel gas is reduced, and the static pressure distribution in the fuel gas supply communication hole 76a is improved. On the other hand, the condensed water adhering to the inner wall surface 150 passes from the water discharge port 152 through the drain channel 146. It is discharged to the gas-liquid separator 142. Thereby, in 2nd Embodiment, the effect similar to said 1st Embodiment is acquired, and also dew condensation water is not stored in the flow path block 144, and an advantage that drainage property improves further. Is obtained.

  FIG. 6 is an explanatory cross-sectional view of a main part of a fuel cell system 160 according to the third embodiment of the present invention.

  The fuel cell system 160 includes a flow path block 162 interposed between the end plate 62b and the ejector 50. Similar to the second embodiment, the flow path block 162 is provided with a bent connection flow path 148 that bends by approximately 90 ° in the vertical upward direction, and is positioned on the inner wall surface 150 in front of the injection passage 116. A recess 164 is formed.

  In the third embodiment configured as described above, the fuel gas discharged from the injection passage 116 to the bent connection flow path 148 is blown to the concave portion 164 of the inner wall surface 150 to reduce the flow velocity and to the concave portion 164. Condensation water adheres. The condensed water is reliably prevented from moving upward from the recess 164 and has an advantage that the condensed water is reliably and smoothly discharged to the drain channel 146 through the water discharge port 152.

  FIG. 7 is an explanatory cross-sectional view of a main part of a fuel cell system 170 according to the fourth embodiment of the present invention.

  The fuel cell system 170 includes a flow path block 172 interposed between the end plate 62 b and the ejector 50. As in the third embodiment, the flow path block 172 has a recess 164 formed in the inner wall surface 150, and a protrusion 174 protruding above the recess 164 toward the bent connection flow path 148. Is provided.

  Accordingly, in the fourth embodiment, the fuel gas discharged from the injection passage 116 to the bent connection flow path 148 is decelerated by the recess 164 and the condensed water is removed by the recess 164. At that time, it is possible to reliably prevent the dew condensation water from moving to the fuel gas supply communication hole 76a side, particularly through the protrusion 174.

  FIG. 8 is a cross-sectional explanatory view of a main part of a fuel cell system 180 according to the fifth embodiment of the present invention.

  The fuel cell system 180 includes a flow path block 182 interposed between the end plate 62 b and the ejector 50. The flow path block 182 is formed with a projection 184 that is located above the injection passage 116 on the inner wall surface 150 and protrudes toward the bent connection flow path 148.

  Therefore, in the fifth embodiment, the fuel gas discharged from the injection passage 116 to the bent connection flow path 148 is decelerated by the inner wall surface 150 and condensed water adheres to the inner wall surface 150. At this time, it is possible to reliably prevent the dew condensation water from moving upward by the protrusion 184, and it is possible to reliably prevent the dew condensation water from being introduced into the fuel gas supply communication hole 76a.

  FIG. 9 is an explanatory cross-sectional view of a main part of a fuel cell system 190 according to the sixth embodiment of the present invention.

  The fuel cell system 190 includes a flow path block 192 interposed between the end plate 62 b and the ejector 50. The flow path block 192 includes a bent connection flow path 194 that connects the injection passage 116 and the fuel gas supply communication hole 76a. The bent connection channel 194 is bent downward in a V shape, and the diffuser 100 is inserted into the inlet 194a, while the fuel gas supply communication hole 76a communicates with the outlet 194b. The drain channel 146 communicates with the V-shaped lower end side of the bent connection channel 194 through the water discharge port 152.

  In the sixth embodiment configured as described above, the fuel gas discharged from the injection passage 116 to the bent connection flow path 194 moves along the shape of the bent connection flow path 194, thereby reducing the flow velocity. Moisture is removed as condensed water. For this reason, it is possible to distribute and supply the fuel gas uniformly and surely to each power generation cell 60 in the fuel cell stack 14, and to prevent the intrusion of condensed water and stably maintain the power generation performance.

  FIG. 10 is a schematic configuration diagram of a fuel cell system 200 according to the seventh embodiment of the present invention.

  The fuel cell system 200 includes a drain valve 202 connected to the drain flow path 146, and the outlet side of the drain valve 202 is connected to the dilution box 58. Therefore, in the seventh embodiment, the dew condensation water discharged to the drain flow path 146 is discharged to the dilution box 58 under the switching action of the drain valve 202.

  FIG. 11 is a cross-sectional explanatory view of a main part of a fuel cell system 210 according to the eighth embodiment of the present invention.

  The fuel cell system 210 includes an end plate 212 instead of the end plate 62b. The end plate 212 is provided with a bent connection flow path 214 having an inlet 214a communicating with the injection passage 116 of the ejector 50 and an outlet 214b communicating with the fuel gas supply communication hole 76a. The bent connection channel 214 is formed with a recess 164 positioned in front of the injection passage 116, and a projection 174 protruding toward the injection passage 116 is provided above the recess 164.

  A resin joint member 216 for mounting the ejector 50 is connected to the end plate 212.

  In the eighth embodiment configured as described above, the ejector 50 is directly attached to the end plate 212 via the resin joint member 216. For this reason, the effect that the weight reduction of the whole fuel cell system 210 and cost reduction are achieved easily is acquired.

  Further, the end plate 212 is formed with a bent connection channel 214, and a projection 174 is provided in the bent connection channel 214. Therefore, the number of parts and the manufacturing cost can be reduced, and the number of assembly steps can be reduced.

  Furthermore, the ejector 50 and the end plate 212 are connected via a resin joint member 216. Accordingly, the resin joint member 216 itself is inclined, so that the relative alignment between the ejector 50 and the end plate 212 is facilitated, and the mounting property is improved.

  In the eighth embodiment, although not shown, the resin joint member 216 may be configured to communicate with the drain channel via the water discharge port (see the second embodiment).

DESCRIPTION OF SYMBOLS 10, 140, 160, 170, 180, 190, 200, 210 ... Fuel cell system 14 ... Fuel cell stack 16 ... Coolant supply mechanism 18 ... Oxidant gas supply mechanism 20 ... Fuel gas supply mechanism 28 ... Coolant supply pipe 30 ... cooling medium discharge pipe 34 ... air supply pipe 36 ... humidifier 38 ... humidified air supply pipe 40 ... off gas supply pipe 44 ... fuel gas tank 45 ... fuel gas pipe 50 ... ejector 52 ... exhaust fuel gas pipe 54 ... return pipe 60 ... power generation cell 62a, 62b, 212 ... end plate 66 ... electrolyte membrane / electrode structure 68, 70 ... separator 72a ... oxidant gas supply communication hole 72b ... oxidant gas discharge communication hole 74a ... cooling medium supply communication hole 74b ... cooling medium discharge communication Hole 76a ... Fuel gas supply communication hole 76b ... Fuel gas discharge communication hole 78 ... Solid polymer battery Membrane 80 ... Anode side electrode 82 ... Cathode side electrode 84 ... Fuel gas flow path 86 ... Cooling medium flow path 88 ... Oxidant gas flow path 90, 144, 162, 172, 182, 192 ... Flow path block 94 ... Main body 98 ... Nozzle 100 ... Diffuser 104 ... Off-gas passage 116 ... Injection passage 120, 148, 194, 214 ... Bent connection passage 120a, 148a, 194a, 214a ... Inlet 120b, 148b, 194b, 214b ... Outlet 126, 150 ... Inner wall surface 142 ... Gas-liquid separator 146 ... Drain flow path 152 ... Water discharge port 164 ... Recess 174, 184 ... Protrusion 202 ... Drain valve 216 ... Resin joint member

Claims (11)

A plurality of power generation cells are stacked in a horizontal direction, an end plate is disposed at an end in the stacking direction, and a reaction gas supply communication hole that supplies at least a reaction gas that is a fuel gas or an oxidant gas along the stacking direction. A fuel cell stack provided;
The reaction gas is mounted on the end plate, and the reaction gas is introduced from the reaction gas outlet into the reaction gas supply communication hole, and the spent reaction gas discharged from the fuel cell stack is mixed with the unused reaction gas. An ejector for returning to the reactive gas outlet,
A fuel cell system comprising:
The fuel cell system, wherein the reaction gas outlet of the ejector and the reaction gas supply hole of the end plate are arranged so as to be shifted from each other with respect to the stacking direction.   2. The fuel cell system according to claim 1, wherein the reactive gas ejection port of the ejector is disposed below the reactive gas supply communication hole of the end plate. 3.   3. The fuel cell system according to claim 1, wherein a water discharge port is provided below the tip of the reactive gas outlet of the ejector. 4.   4. The fuel cell system according to claim 2, wherein a flow path is formed in front of the reaction gas outlet of the ejector so as to communicate with the reaction gas supply communication hole of the end plate in an upward direction. A fuel cell system, wherein an inner wall surface is provided so as to be orthogonal to the reactive gas ejection direction and extend in the vertical direction.   5. The fuel cell system according to claim 4, wherein the inner wall surface is formed with a protrusion that is located above the reactive gas jet port and protrudes from the end plate side into the flow path. Battery system.   6. The fuel cell system according to claim 4, wherein a concave portion is formed in the inner wall surface in front of the reactive gas outlet of the ejector. The fuel cell system according to any one of claims 1 to 6, wherein a flow path block is interposed between the end plate and the ejector,
The fuel cell system according to claim 1, wherein the flow path block includes a bent connection flow path having an inlet communicating with the reactive gas ejection port and an outlet communicating with the reactive gas supply communication hole.   The fuel cell system according to any one of claims 1 to 6, wherein the end plate has a bent connection flow having an inlet communicating with the reactive gas ejection port and an outlet communicating with the reactive gas supply communication hole. A fuel cell system provided with a path.   9. The fuel cell system according to claim 8, wherein a resin joint member for mounting the ejector is connected to the end plate. A plurality of power generation cells are stacked in a horizontal direction, an end plate is disposed at an end in the stacking direction, and a reaction gas supply communication hole that supplies at least a reaction gas that is a fuel gas or an oxidant gas along the stacking direction. A fuel cell stack provided;
The reaction gas is mounted on the end plate, and the reaction gas is introduced from the reaction gas outlet into the reaction gas supply communication hole, and the spent reaction gas discharged from the fuel cell stack is mixed with the unused reaction gas. An ejector for returning to the reactive gas outlet,
A fuel cell system comprising:
A bent connecting flow path that connects the reactive gas ejection port of the ejector and the reactive gas supply communication hole of the end plate;
The fuel cell system, wherein the bent connection channel has a bent portion bent downward in a V shape. The fuel cell system according to claim 10, wherein a flow path block is interposed between the end plate and the ejector,
The fuel cell system, wherein the flow path block includes the bent connection flow path having an inlet communicating with the reactive gas ejection port and an outlet communicating with the reactive gas supply communication hole.

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