JP6936036B2 - Fuel cell and fuel cell system - Google Patents

Description

The present invention relates to a fuel cell and a fuel cell system.

Conventionally, a fuel cell that generates electric energy by a chemical reaction between a fuel gas and an oxidant gas is known. In a fuel cell, a plurality of cells capable of generating electric energy by a chemical reaction between a fuel gas and an oxidant gas are stacked to increase the output voltage of the fuel cell. At this time, it is required to supply a sufficient amount of fuel gas to each of the plurality of stacked cells so that the power generation performance of the cells can be sufficiently exhibited. For example, Patent Document 1 describes a fuel cell including a plurality of cells and a fuel gas supply pipe provided in a fuel gas manifold formed so as to penetrate a plurality of stacked cells in a stacking direction. ing.

Japanese Unexamined Patent Publication No. 2004-327425

In the fuel cell described in Patent Document 1, the fuel gas supply pipe has a plurality of injection holes capable of injecting fuel gas into each of the plurality of cells. When the fuel gas is supplied to the fuel gas supply pipe from one end side of the fuel gas supply pipe, the pressure of the fuel gas injected from the injection hole on the other end side of the fuel gas supply pipe is the pressure on one end side of the fuel gas supply pipe. It is lower than the pressure of the fuel gas injected from the injection hole. Therefore, a sufficient amount of fuel gas cannot be supplied to the cell located on the other end side of the fuel gas supply pipe.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a fuel cell capable of increasing the output voltage while stabilizing it.

One aspect of the present invention is a fuel cell, which comprises a plurality of cells (25), a fuel gas manifold (261), and a plurality of fuel gas supply pipes (101, 102, 21, 22, 23, 36, 37). , 38, 42).
The cells are formed so as to be able to generate electric energy by the reaction of the fuel gas and the oxidant gas, and are stacked along one direction.
The fuel gas manifold communicates with the fuel gas flow path (260) of each of the plurality of cells, and the fuel gas can flow through the manifold.
The fuel gas supply pipe is housed in the fuel gas manifold. The fuel gas supply pipe is formed so as to extend along one direction from one end side in one direction of the plurality of cells, and can supply fuel gas to the cells.
The fuel gas supply pipe has a plurality of injection holes (210, 220, 230, 360, 370, 380, 423, 426, 103, 104) capable of injecting fuel gas toward each of the plurality of cells.
In the fuel cell of the present invention, the first fuel gas supply pipes (23, 38, 102) of the plurality of fuel gas supply pipes are located on the other end side cells (257) located on the other end side in one direction of the plurality of cells. the fuel gas Ru Tei provided to be supplied.

The fuel cell of the present invention includes a plurality of fuel gas supply pipes housed in a fuel gas manifold communicating with a fuel gas flow path of each of the plurality of cells. Of the plurality of fuel gas supply pipes, the first fuel gas supply pipe can supply fuel gas to the other end cell located on the other end side opposite to one end side in one direction in which fuel gas is supplied. It is provided in. As a result, a sufficient amount of fuel gas can be supplied to the other end cell so that the power generation performance of the cell can be sufficiently exhibited, so that electric energy is stably generated in each of the plurality of stacked cells. At the same time, the power generation performance of each of the plurality of cells can be fully exhibited. Therefore, the fuel cell of the present invention can be increased while stabilizing the output voltage.

It is a conceptual diagram of the fuel cell system by 1st Embodiment. It is a schematic diagram of the fuel cell according to 1st Embodiment. FIG. 3 is a cross-sectional view taken along the line III of FIG. It is a characteristic diagram which shows the relationship between the hydrogen utilization rate of the fuel cell and the stack voltage by 1st Embodiment. It is a characteristic figure which shows the relationship between the cell stacking position of the fuel cell and the output voltage by 1st Embodiment. It is a schematic diagram of the fuel cell according to the 2nd Embodiment. It is a schematic diagram of the fuel cell according to the third embodiment. It is sectional drawing of the fuel gas supply pipe provided in the fuel cell according to 4th Embodiment. It is a conceptual diagram of the fuel cell system by 5th Embodiment. It is a schematic diagram of the switching valve provided in the fuel cell system according to the fifth embodiment. It is a flowchart of the method of switching the supply destination of hydrogen in the fuel cell system according to 5th Embodiment. It is a schematic diagram explaining the operation of the switching valve provided in the fuel cell system according to the fifth embodiment. It is a schematic diagram explaining the operation of the switching valve provided in the fuel cell system according to the fifth embodiment, and is the schematic diagram explaining the operation different from FIG. It is a schematic diagram explaining the operation of the fuel cell system by 5th Embodiment. It is a schematic diagram of the switching valve provided in the fuel cell system according to the sixth embodiment. It is a schematic diagram of the switching valve provided in the fuel cell system according to the seventh embodiment. It is a schematic diagram of the switching valve provided in the fuel cell system according to the eighth embodiment.

Hereinafter, embodiments of the fuel cell and the fuel cell system of the present invention will be described with reference to the drawings. In a plurality of embodiments, substantially the same configurations are designated by the same reference numerals and description thereof will be omitted.

(First Embodiment)
The fuel cell according to the first embodiment is applied to, for example, an electric vehicle in which a motor is driven and traveled by electric energy generated by the fuel battery. FIG. 1 shows a conceptual diagram of a fuel cell system 5 including a fuel cell 1. The fuel cell system 5 includes a fuel cell 1, a fuel gas flow system 11, an oxidant gas flow system 12, a cooling system 13, and an ECU 15. The fuel cell system 5 generates electrical energy by utilizing an electrochemical reaction between hydrogen as a "fuel gas" and oxygen as an "oxidizing agent gas".

The fuel cell 1 is, for example, a solid polymer electrolyte fuel cell. Air containing hydrogen and oxygen and cooling water are supplied to the fuel cell 1. The detailed configuration of the fuel cell 1 will be described later.

The fuel gas distribution system 11 includes a hydrogen tank 110, a hydrogen tank pipe 111, a hydrogen discharge pipe 112, a first sealing valve 113, a pressure regulating valve 114 as a "pressure adjusting unit", a second blocking valve 115, and a third sealing valve. Has 116.
The hydrogen tank 110 can store hydrogen supplied to the fuel cell 1. The hydrogen tank 110 can be filled with high-pressure hydrogen.

The hydrogen tank pipe 111 is connected to the hydrogen tank 110. The hydrogen tank pipe 111 is connected to the hydrogen supply pipes 21, 22, 23 of the fuel cell 1 on the side opposite to the side connected to the hydrogen tank 110. That is, the hydrogen tank pipe 111 has three branches on the side opposite to the side connected to the hydrogen tank 110.

The hydrogen discharge pipe 112 is connected to a hydrogen manifold 262 (see FIG. 3) included in the fuel cell 1. Hydrogen discharged from the fuel cell 1 flows through the hydrogen discharge pipe 112.

The first sealing valve 113, the pressure regulating valve 114, and the second sealing valve 115 are provided in the hydrogen tank pipe 111 in this order from the hydrogen tank 110. The first sealing valve 113, the pressure regulating valve 114, and the second sealing valve 115 are electrically connected to the ECU 15. The pressure regulating valve 114 is a so-called injector, and regulates the pressure of hydrogen supplied by the hydrogen tank 110.
When hydrogen is supplied to the fuel cell 1, the first block valve 113 and the second block valve 115 are opened in response to a command from the ECU 15. At this time, the pressure regulating valve 114 adjusts the pressure of hydrogen supplied by the hydrogen tank 110 to a desired pressure in response to a command from the ECU 15. Further, when the vehicle is stopped, the first seal valve 113 and the second seal valve 115 are closed for safety.

The third sealing valve 116 is provided in the hydrogen discharge pipe 112. The third sealing valve 116 is electrically connected to the ECU 15. When the third sealing valve 116 is opened in response to a command from the ECU 15, impurities such as unreacted hydrogen, steam or water discharged from the fuel cell 1, nitrogen and oxygen mixed in the unreacted hydrogen are discharged.

The oxidant gas distribution system 12 is formed so as to communicate with the atmosphere. The oxidant gas flow system 12 includes an air compression unit 120, an air supply pipe 121, an air discharge pipe 122, a pressure regulating valve 123, and a water condensing unit 124.
The air compression unit 120 is provided in the air supply pipe 121. The air compression unit 120 supplies the fuel cell 1 while compressing the atmosphere.

The air supply pipe 121 is connected to the air manifolds 271,272,273 (see FIG. 3) included in the fuel cell 1. The air supplied to the fuel cell 1 flows through the air supply pipe 121.

The air discharge pipe 122 is connected to the air manifold 274,275,276 (see FIG. 3) included in the fuel cell 1. The air discharged from the fuel cell 1 flows through the air discharge pipe 122.

The pressure regulating valve 123 is provided in the air discharge pipe 122. The pressure regulating valve 123 regulates the pressure of the air discharged from the fuel cell 1 so that the pressure of the air supplied to the fuel cell 1 becomes a desired pressure.
The water condensing unit 124 condenses and recovers the water contained in the air flowing through the air discharge pipe 122. The recovered water is supplied to the fuel cell 1 by a pump (not shown).

The cooling system 13 includes a cooling pipe 131, a water pump 132, a radiator 133, a fan 134, a bypass pipe 135, and a flow path switching valve 136. The cooling system 13 maintains the temperature of the fuel cell 1 so that it is, for example, a permissible temperature or less and about 80 ° C. in order to prevent damage to the electrolyte membrane of the fuel cell 1 while ensuring power generation efficiency.
The cooling pipe 131 is connected to the cooling water manifold 281,282,283,284,285,286 (see FIG. 3) included in the fuel cell 1. The cooling pipe 131 flows cooling water for cooling the fuel cell 1.

The water pump 132 circulates cooling water in the cooling pipe 131.
The radiator 133 cools the cooling water flowing through the cooling pipe 131. The fan 134 is electrically connected to the ECU 15 and rotates in response to a command from the ECU 15 to adjust the degree of cooling of the cooling water in the radiator 133.

The bypass pipe 135 bypasses a part of the cooling water flowing through the cooling pipe 131 so as not to pass through the radiator 133. At the confluence of the cooling pipe 131 and the bypass pipe 135, a flow path switching valve 136 capable of adjusting the flow rate of the cooling water flowing through the bypass pipe 135 is provided.

The ECU 15 is composed of a well-known microcomputer equipped with a CPU, ROM, RAM, I / O, and the like. The ECU 15 is electrically connected to the first sealing valve 113, the pressure regulating valve 114, the second blocking valve 115, the third sealing valve 116, the pressure regulating valve 123, the fan 134, and the flow path switching valve 136. The ECU 15 executes various calculations and the like according to a program stored in a ROM or the like according to the running state of the electric vehicle equipped with the fuel cell system 5 and the operation of the driver who drives the electric vehicle.

Next, the configuration of the fuel cell 1 will be described with reference to FIGS. 2 and 3. FIG. 2 shows an external view of the fuel cell 1. The fuel cell 1 includes a cell 25, two electrodes 31, 32, and hydrogen supply pipes 21, 22, and 23 as "fuel gas supply pipes".

The cell 25 has an electrolyte membrane, an MEA having electrodes provided on both side surfaces of the electrolyte membrane, and a pair of separators sandwiching the MEA. The cell 25 is formed so as to be able to flow while separating hydrogen and air. The cell 25 can generate a potential difference, that is, electrical energy, between the anode and the cathode of the pair of separators by the reaction of hydrogen and oxygen contained in air.
The fuel cell 1 has a plurality of cells 25. The plurality of cells 25 are stacked along the stacking direction as "one direction" (the direction indicated by the solid arrow Ld0 shown in FIG. 2) to form a so-called cell stack. The anode and cathode of each of the plurality of cells 25 are electrically connected in series.

The fuel cell 1 is a hydrogen manifold 261,262 as a "fuel gas manifold" formed along the stacking direction, and an air manifold 271,272,273,274,275 as an "oxidant gas manifold". It has 276 and cooling water manifolds 281,282,283,284,285,286. The hydrogen manifold 261,262, the air manifold 271,272, 273, 274, 275,276, and the cooling water manifold 281,282,283,284,285,286 form a plurality of stacked cells 25. It is formed to penetrate.

As shown in FIG. 3, the hydrogen manifolds 261,262 communicate with the hydrogen flow path 260 as a “fuel gas flow path” capable of flowing hydrogen formed in the separator 250 of each of the plurality of cells 25. Is formed. As shown in FIG. 3, the hydrogen manifold 261 is formed in the substantially rectangular cell 25 along the side surface 251 of the plurality of cells 25. The hydrogen manifold 262 is formed along the side surface 252 substantially parallel to the side surface 251 of the plurality of cells 25. As shown in FIG. 3, the hydrogen manifold 261 and the hydrogen manifold 262 are provided at positions symmetrical with respect to a point on the substantially center C25 of the cell 25. The hydrogen manifold 261 and the hydrogen manifold 262 communicate with each other via the hydrogen flow path 260.

The air manifolds 271,272,273,274,275,276 are formed so as to communicate air formed in a separator (not shown) different from the separator 250 of each of the plurality of cells 25 to a flowable air flow path. Has been done. The air manifolds 271,272,273 are formed in the substantially rectangular cell 25 along the side surface 253 located at a position substantially perpendicular to the side surfaces 251,252 of the plurality of cells 25, as shown in FIG. ing. The air manifolds 274, 275 and 276 are formed along the side surface 254 substantially parallel to the side surface 253 of the plurality of cells 25. The air manifolds 271,272,273 and the air manifolds 274,275,276 communicate with each other via the air flow path of the separator.

The cooling water manifolds 281, 228, 283, 284, 285, 286 are formed so that the cooling water flowing through the cell 25 can flow. The cooling water manifolds 281, 282, 283 are formed in the substantially rectangular cell 25 so as to be adjacent to the hydrogen manifold 261 along the side surfaces 251 of the plurality of cells 25, as shown in FIG. The cooling water manifolds 284, 285 and 286 are formed so as to be adjacent to the hydrogen manifold 262 along the side surfaces 252 of the plurality of cells 25.

The electrodes 31 and 32 are provided at both ends of the plurality of stacked cells 25 in the stacking direction, respectively. The electrodes 31 and 32 output the electrical energy generated by the plurality of cells 25 to the outside.

The hydrogen supply pipes 21, 22, and 23 are inserted into the hydrogen manifold 261. The hydrogen supply pipes 21, 22, and 23 are formed so as to extend in one direction from one end side in the stacking direction.
Each of the hydrogen supply pipes 21, 22, and 23 has injection holes 210, 220, and 230 capable of injecting hydrogen. The injection holes 210, 220, and 230 are formed so as to correspond to the respective positions of the plurality of cells 25. Specifically, the injection holes 210, 220, 230 are formed so that the cell 25 is located ahead of the hydrogen injection direction in the injection holes 210, 220, 230.
As shown in FIG. 2, the injection holes 210, 220, and 230 are formed so that the inner diameter increases as the distance from one end side in the stacking direction increases. In the present embodiment, each of the hydrogen supply pipes 21, 22, and 23 is formed so that the lengths at which the injection holes 210, 220, and 230 are formed are substantially the same.

The hydrogen supply pipe 21 is formed so that hydrogen flowing through the hydrogen tank pipe 111 can be supplied to one end side in the stacking direction in the plurality of cells 25, for example, the cell 255 as the “one end side cell” shown in FIG.
The hydrogen supply pipe 22 is formed so as to be able to supply hydrogen flowing through the hydrogen tank pipe 111 to substantially the center of the plurality of cells 25 in the stacking direction, for example, the cell 256 shown in FIG.
The hydrogen supply pipe 23 as the "first fuel gas supply pipe" has a hydrogen tank pipe 111 in the other end side in the stacking direction in the plurality of cells 25, for example, the cell 257 as the "other end side cell" shown in FIG. It is formed so that it can supply flowing hydrogen.

Next, the effect of the fuel cell 1 according to the present embodiment will be described with reference to FIGS. 4 and 5 showing the experimental results by the inventors.

FIG. 4 shows a change in the magnitude of the stack voltage with respect to a change in the hydrogen utilization rate in the fuel cell 1. In FIG. 4, the horizontal axis shows the hydrogen utilization rate in the plurality of cells 25, and the vertical axis shows the magnitude of the stack voltage. In FIG. 4, as a comparative example, the magnitude of the stack voltage with respect to the hydrogen utilization rate in a fuel cell that does not have a hydrogen supply pipe and supplies hydrogen to a plurality of cells only by a hydrogen manifold is shown by a dotted line Lc1.
As shown in FIG. 4, in the fuel cell of the comparative example, it was clarified that the stack voltage decreased relatively significantly when the hydrogen utilization rate decreased. On the other hand, in the fuel cell 1, as shown by the solid line L11 in FIG. 4, it was clarified that the degree of decrease in the stack voltage when the hydrogen utilization rate decreased was smaller than that in the comparative example.

FIG. 5 shows the magnitude of the output voltage of the cell 25 with respect to the stacking position of the cell 25 in the fuel cell 1. In FIG. 5, the horizontal axis shows the stacking position of the cells 25. On the horizontal axis, one end side in the stacking direction, which is the side where hydrogen is supplied, is located on the left side of the paper surface, and the other end side in the stacking direction, which is the opposite side to the side where hydrogen is supplied, is located on the right side of the paper surface. .. Further, in FIG. 5, the vertical axis shows the magnitude of the output voltage of one cell 25. In FIG. 5, the magnitude of the output voltage with respect to the stacking position of the cells in the fuel cell of the comparative example shown in FIG. 4 is shown by the dotted line Lc2.
As shown in FIG. 5, in the fuel cell of the comparative example, it was clarified that the output voltage of the cell decreased relatively significantly as the distance from one end side increased. On the other hand, in the fuel cell 1, as shown by the solid line L12 in FIG. 5, it was clarified that the decrease in the output voltage of the cell 25 was relatively small and the voltage distribution was relatively uniform even when the cell 25 was separated from one end side.

(A) The fuel cell 1 according to the first embodiment includes a plurality of hydrogen supply pipes 21, 22, 23 capable of supplying hydrogen to each of the plurality of cells 25. Of the plurality of hydrogen supply pipes 21, 22, 23, the hydrogen supply pipe 23 is provided so as to be able to supply hydrogen to the other end side of the plurality of cells 25 in the stacking direction, for example, the cell 257 shown in FIG. As a result, a sufficient amount of hydrogen can be supplied to the cell 257, which is relatively difficult to distribute hydrogen, so that electric energy can be stably generated in each of the plurality of stacked cells 25, and a plurality of cells 25 can be stably generated. The power generation performance of each of the cells 25 can be fully exhibited. Therefore, the fuel cell 1 can be increased while stabilizing the output voltage.

(B) The injection holes 210, 220, and 230 of the hydrogen supply pipes 21, 22, and 23 are formed so as to correspond to the respective positions of the plurality of cells 25. As a result, the hydrogen injected from the injection holes 210, 220, and 230 is reliably supplied to each of the plurality of cells 25. Further, the water in the hydrogen flow path 260 included in the cell 25 can be discharged by the flow velocity and pressure pulsation of hydrogen injected from the injection holes 210, 220, 230. Therefore, the output voltage can be further stabilized.

(C) In the fuel cell 1, the injection holes 210, 220, and 230 of the hydrogen supply pipes 21, 22, and 23 are formed so that the inner diameters increase as the inner diameter increases from one end side in the stacking direction. As a result, even if the pressure of hydrogen in the hydrogen supply pipes 21, 22, and 23 decreases as the distance from one end side in the stacking direction decreases, a sufficient amount of hydrogen is supplied to the corresponding cell 25 on the other end side in the stacking direction. can do. Therefore, the fuel cell 1 can further stabilize the output voltage and further increase the output voltage.

(Second Embodiment)
The fuel cell according to the second embodiment will be described with reference to FIG. The second embodiment is different from the first embodiment in that it includes a hydrogen concentration sensor.

The configuration of the fuel cell 2 according to the second embodiment will be described with reference to FIG. The fuel cell 2 includes cells 25, two electrodes 31, 32, hydrogen supply pipes 21, 22, 23, and a hydrogen concentration sensor 361, 362, 371, 372, 381, 382 as a "fuel gas concentration detector". Be prepared.

The hydrogen concentration sensors 361, 371 and 381 are provided in the hydrogen manifold 261. The hydrogen concentration sensors 361, 371 and 381 are electrically connected to the ECU 15. The hydrogen concentration sensor 361 is provided near the other end side of the hydrogen supply pipe 21 in the stacking direction. The hydrogen concentration sensor 371 is provided in the vicinity of the other end side of the hydrogen supply pipe 22 in the stacking direction. The hydrogen concentration sensor 381 is provided in the vicinity of the other end side of the hydrogen supply pipe 23 in the stacking direction.
The hydrogen concentration sensor 361, 371, 381 detects the hydrogen concentration in the hydrogen manifold 261 and outputs a signal to the ECU 15 according to the detected hydrogen concentration.

The hydrogen concentration sensor 362, 372, 382 is provided in the hydrogen manifold 262. The hydrogen concentration sensors 362,372,382 are electrically connected to the ECU 15. The hydrogen concentration sensor 362 is provided in the vicinity of the outlet where hydrogen is discharged in the cell 25 through which hydrogen supplied by the hydrogen supply pipe 21 flows. The hydrogen concentration sensor 371 is provided in the vicinity of the outlet where hydrogen is discharged in the cell 25 through which hydrogen supplied by the hydrogen supply pipe 22 flows. The hydrogen concentration sensor 381 is provided in the vicinity of the outlet where hydrogen is discharged in the cell 25 through which hydrogen supplied by the hydrogen supply pipe 23 flows.
The hydrogen concentration sensor 362, 372, 382 detects the hydrogen concentration in the hydrogen manifold 262 and outputs a signal to the ECU 15 according to the detected hydrogen concentration.

The fuel cell 2 according to the second embodiment includes a hydrogen concentration sensor 361, 362, 371, 372, 381, 382 that can detect the hydrogen concentration in the hydrogen manifolds 261,262. The ECU 15 controls the operation of the pressure regulating valve 114 so as to suppress variations in the hydrogen concentration flowing through the plurality of cells 25 based on the hydrogen concentration detected by the hydrogen concentration sensor 361, 362, 371, 372, 381, 382. As a result, for example, even if the inner diameters of the injection holes 210, 220, 230 of the hydrogen supply pipes 21, 22, and 23 vary due to manufacturing errors, it is possible to suppress variations in the hydrogen concentration flowing through the plurality of cells 25. As a result, the fuel cell 2 can make the amount of hydrogen supplied to the plurality of cells 25 the optimum amount for power generation. Therefore, the second embodiment has the same effect as that of the first embodiment, and can further stabilize the output voltage and further increase the output voltage.

Further, when the gas contained in the air permeates the hydrogen flow path 260 side of the separator 250, the hydrogen concentration may vary as an impurity mixed in the hydrogen. In the fuel cell 2, the hydrogen concentration sensor 362, 372, 382 detects the hydrogen concentration in the vicinity of the outlet where hydrogen is discharged in the cell 25, and outputs the hydrogen concentration to the ECU 15. This makes it possible to further suppress variations in hydrogen concentration.

(Third Embodiment)
The fuel cell according to the third embodiment will be described with reference to FIG. In the third embodiment, the region where the injection hole is formed in the hydrogen supply pipe is different from that in the first embodiment.

The configuration of the fuel cell 3 according to the third embodiment will be described with reference to FIG. The fuel cell 3 includes a cell 25, two electrodes 31, 32, and hydrogen supply pipes 36, 37, 38 as "fuel gas supply pipes".

The hydrogen supply pipes 36, 37, 38 are inserted into the hydrogen manifold 261. The hydrogen supply pipes 36, 37, 38 are connected to the hydrogen tank pipe 111. That is, the hydrogen flowing through the hydrogen tank pipe 111 branches into the hydrogen supply pipes 36, 37, 38. The hydrogen supply pipes 36, 37, and 38 are formed so as to extend from one end side in the stacking direction along the stacking direction. The hydrogen supply pipes 36, 37, 38 can supply hydrogen to a plurality of cells 25.

Each of the hydrogen supply pipes 36, 37, 38 has injection holes 360, 370, 380 capable of injecting hydrogen. The injection holes 360, 370, and 380 are formed so as to correspond to the respective positions of the plurality of cells 25. Specifically, the injection holes 360, 370, 380 are formed so that the cell 25 is located ahead of the hydrogen injection direction in the injection holes 360, 370, 380. As shown in FIG. 7, the injection holes 360, 370, and 380 are formed so that the inner diameter increases as the distance from one end side in the stacking direction increases.

In the present embodiment, the lengths at which the injection holes 360, 370, and 380 are formed are different in the hydrogen supply pipes 36, 37, and 38, respectively. In the present embodiment, the region A37 in which the injection holes 370 of the hydrogen supply pipe 37 are formed is narrower than the regions A36 and A38 in which the injection holes 360 and 380 of the hydrogen supply pipes 36 and 38 are formed. As a result, the number of injection holes 360, 380 of the hydrogen supply pipes 36 and 38 is smaller than the number of injection holes 370 of the hydrogen supply pipe 37.

The hydrogen supply pipe 36 as the "second fuel gas supply pipe" is formed so as to be able to supply hydrogen to one end side in the stacking direction including the cell 255.
The hydrogen supply pipe 37 as the “other fuel gas supply pipe” is formed so as to be able to supply hydrogen to a plurality of cells 25 substantially in the center in the stacking direction, for example, the cell 256 shown in FIG.
The hydrogen supply pipe 38 as the "first fuel gas supply pipe" is formed so as to be able to supply hydrogen to the other end side in the stacking direction including the cell 257.

In a fuel cell, since heat dissipation at both ends of a plurality of stacked cells is large due to the structure, the temperature of the cells at both ends in the stacking direction of the plurality of cells tends to decrease. Therefore, water may stay in the flow path through which the fuel gas or oxidant gas contained in the cell flows.
In the fuel cell 3, hydrogen supply pipes 36, 38 having a relatively small number of injection holes 360, 380 are provided so that hydrogen can be supplied to both ends in the stacking direction. As a result, the amount of hydrogen passing through the injection holes 360 and 380 of the hydrogen supply pipes 36 and 38 becomes relatively large, so that the water convected in the hydrogen flow path 260 due to the decrease in temperature can be discharged by the hydrogen flow. can. Therefore, the third embodiment has the same effect as that of the first embodiment, and can recover the output voltage of the cell 25 which may be lowered by the water staying in the hydrogen flow path 260.

(Fourth Embodiment)
The fuel cell according to the fourth embodiment will be described with reference to FIG. In the fourth embodiment, the configuration of the hydrogen supply pipe is different from that in the first embodiment.

The configuration of the fuel cell according to the fourth embodiment will be described with reference to FIG. The fuel cell according to the fourth embodiment includes a cell 25, two electrodes 31, 32, hydrogen supply pipes 21, 42, 23, and a drive unit 44. The hydrogen supply pipe 42 corresponds to the "fuel gas supply pipe" described in the claims.

The hydrogen supply pipe 42 is inserted into the hydrogen manifold 261. The hydrogen supply pipe 42 is connected to the hydrogen tank pipe 111. That is, the hydrogen flowing through the hydrogen tank pipe 111 branches into the hydrogen supply pipes 21, 42, and 23. The hydrogen supply pipe 42 is formed so as to extend from one end side in the stacking direction along the stacking direction. The hydrogen supply pipe 42 can supply hydrogen to the cell 25 substantially at the center in the stacking direction.

As shown in FIG. 8, the hydrogen supply pipe 42 has an outer pipe 421 and an inner pipe 422.
The outer pipe 421 is an outer shell of the hydrogen supply pipe 42 formed in a cylindrical shape, and as shown in FIG. 8, has a cross-sectional shape perpendicular to the central axis C42 of the outer pipe 421 along the direction in which hydrogen flows. It is formed in a substantially annular shape. The outer tube 421 has an outer injection hole 423 on the side wall. The outer injection hole 423 is formed so that the inner diameter increases as the distance from one end side in the stacking direction increases.

The inner pipe 422 is provided so as to be rotatable relative to the outer pipe 421 coaxially with the central axis C42 on the radial inside of the outer pipe 421. The inner pipe 422 has a substantially annular cross-sectional shape perpendicular to the central axis C42, and the outer wall 424 is slidably formed on the inner wall 425 of the outer pipe 421. The inner pipe 422 has a hydrogen supply path 420 formed so as to extend along the central axis C42, and an inner injection hole 426 capable of communicating the hydrogen supply path 420 and the outer injection hole 423.

The drive unit 44 is connected to the inner pipe 422. The drive unit 44 outputs a rotational torque that allows the inner pipe 422 to rotate relative to the outer pipe 421. The drive unit 44 outputs rotational torque in response to a command from the electrically connected ECU 15.

In the fuel cell according to the fourth embodiment, when hydrogen is supplied to the cell 25 by the hydrogen supply pipe 42, the inner pipe 422 rotates with respect to the outer pipe 421, and as shown in FIG. 8A, the inner injection hole 426 And the outer injection hole 423 are communicated with each other. As a result, hydrogen flowing through the hydrogen supply path 420 is supplied to the corresponding cell 25 through the inner injection hole 426 and the outer injection hole 423.
Further, when the amount of hydrogen supplied to the cell 25 is set to 0, the inner pipe 422 is rotated with respect to the outer pipe 421, and as shown in FIG. 8B, the inner injection hole 426 is relative to the outer injection hole 423. To shift the position. As a result, the hydrogen supply path 420 and the outer injection hole 423 are cut off, so that the supply of hydrogen to the cell 25 is stopped.

As described above, in the fuel cell according to the fourth embodiment, the hydrogen supply path 420 and the cell 25 can be communicated or cut off by the relative rotation of the inner pipe 422 with respect to the outer pipe 421. Thereby, the hydrogen supply amount can be controlled in the hydrogen supply pipe 42. Therefore, the fourth embodiment has the same effect as that of the first embodiment, and the amount of hydrogen supplied to the cell 25 can be controlled with high accuracy.

(Fifth Embodiment)
The fuel cell system according to the fifth embodiment will be described with reference to FIGS. 9 to 14. The fifth embodiment is different from the first embodiment in that a switching valve is provided.

FIG. 9 shows a conceptual diagram of the fuel cell system 6 including the fuel cell 10. The fuel cell system 6 includes a fuel cell 10, a fuel gas flow system 11, a switching valve 60, a pressure detection unit 691 as a "physical quantity detection unit", a hydrogen concentration sensor 692 as a "physical quantity detection unit", and an oxidizing agent gas distribution system 12. , Cooling system 13, and ECU 15. The fuel cell system 6 generates electrical energy by utilizing an electrochemical reaction between hydrogen and oxygen.

The fuel cell 10 is, for example, a solid polymer electrolyte fuel cell. Air containing hydrogen and oxygen and cooling water are supplied to the fuel cell 10. The fuel cell 10 includes a cell 25, two electrodes 31, 32, and hydrogen supply pipes 101, 102 as "fuel gas supply pipes".

The hydrogen supply pipes 101 and 102 are inserted into the hydrogen manifold 261. The hydrogen supply pipes 101 and 102 are connected to the switching valve 60. The hydrogen flowing through the hydrogen tank pipe 111 branches to the hydrogen supply pipes 101 and 102 at the switching valve 60.
The hydrogen supply pipe 101 is formed so as to extend from one end side in the stacking direction along the stacking direction. The hydrogen supply pipe 101 has an injection hole 103 capable of injecting hydrogen. The injection holes 103 are formed so as to correspond to the respective positions of all the cells 25 included in the fuel cell 10.
The hydrogen supply pipe 102 is formed so as to extend from one end side in the stacking direction along the stacking direction. The hydrogen supply pipe 102 has an injection hole 104 capable of injecting hydrogen. The injection hole 104 is formed so as to correspond to the position of the cell 25 on the other end side in the stacking direction, for example, the cell 257 shown in FIG.

The switching valve 60 is provided in the hydrogen tank pipe 111 between the pressure regulating valve 114 and the fuel cell 10. The switching valve 60 switches the hydrogen supply destination to the hydrogen supply pipe 101 or the hydrogen supply pipe 102 according to the supply pressure of hydrogen flowing through the hydrogen tank pipe 111. As shown in FIG. 10, the switching valve 60 has a first housing 61, a second housing 62, a valve member 63, and an urging member 64.

The first housing 61 is formed in a substantially bottomed cylindrical shape. The first housing 61 has an introduction port 611, a first outlet port 612, and a second outlet port 613.
The introduction port 611 is formed on the radial outer side wall 614 of the first housing 61. In the introduction port 611, hydrogen whose pressure is adjusted by the pressure regulating valve 114 can be introduced into the internal space 600 as "inside the housing" of the first housing 61.
The first outlet 612 is formed at the bottom 615 of the first housing 61. The first outlet 612 is connected to the hydrogen supply pipe 101. The first outlet 612 can derive hydrogen in the internal space 600 to the hydrogen supply pipe 101.
The second outlet 613 is a side wall 614 of the first housing 61, and is formed on the side opposite to the introduction port 611 with the central axis C60 of the switching valve 60 interposed therebetween. The second outlet 613 is connected to the hydrogen supply pipe 102. The second outlet 613 can lead the hydrogen in the internal space 600 to the hydrogen supply pipe 102.

The second housing 62 is a substantially flat plate-shaped member formed so as to close the opening of the first housing 61.

The valve member 63 is provided so as to be reciprocally movable in the internal space 600. The valve member 63 has a contact portion 631, a first communication portion 632, a shaft portion 633, and a second communication portion 634.
The contact portion 631 is provided on the side of the first outlet 612 in the internal space 600. The contact portion 631 is formed so as to be able to contact the edge portion 616 on the internal space 600 side of the first outlet 612.

The first series passage portion 632 is provided on the second housing 62 side of the contact portion 631. In the first series passage portion 632, the outer wall surface 635 on the outer side in the radial direction is formed so as to be slidable on the inner wall surface 617 of the side wall 614 of the first housing 61. As a result, the first communication unit 632 divides the internal space 600 into a space 601 as a "first space" on the first outlet 612 side and a space 602 communicating with the introduction port 611. The first communication unit 632 has an orifice 636 that communicates the space 601 and the space 602.

The shaft portion 633 is provided on the second housing 62 side of the first series passage portion 632. The shaft portion 633 is formed so that the outer diameter is smaller than the outer diameter of the first communication portion 632 and the outer diameter of the second communication portion 634. The shaft portion 633 has an opening 637 that communicates with the introduction port 611.

The second communication portion 634 is provided on the second housing 62 side of the shaft portion 633. The second communication portion 634 is formed so that the end surface 638 as the "second pressure receiving surface" on the second housing 62 side can come into contact with the end surface 621 on the internal space 600 side of the second housing 62. In the second communication portion 634, the outer wall surface 639 on the outer side in the radial direction is slidably formed on the inner wall surface 617 of the side wall 614 of the first housing 61. As a result, the second communication unit 634 divides the internal space 600 into a space 602 and a space 603 (see FIG. 12) as a "second space" capable of communicating with the second outlet 613.

The second communication portion 634 has an opening 641 in the end face 638. The opening 641 and the opening 637 of the shaft portion 633 are communicated with each other by a communication passage 642. As a result, the communication passage 642 can communicate with the space 602 and the space 603.

The urging member 64 is provided in the space 601. One end of the urging member 64 is in contact with the inner wall surface of the bottom 615 of the first housing 61. The other end of the urging member 64 is in contact with the end surface 643 on the bottom 615 side of the first series passage portion 632. The urging member 64 is a valve member 63 so that the contact portion 631 and the edge portion 616 of the first housing 61 are separated from each other, and the end surface 638 of the second communication portion 634 and the end surface 621 of the second housing 62 are in contact with each other. To urge.

The pressure detection unit 691 is provided in the hydrogen tank pipe 111 between the pressure regulating valve 114 and the switching valve 60. The pressure detection unit 691 detects the pressure of hydrogen whose pressure is adjusted by the pressure regulating valve 114. The pressure detection unit 691 outputs a signal corresponding to the detected hydrogen pressure to the ECU 15.

The hydrogen concentration sensor 692 is provided in the hydrogen manifold 261. The hydrogen concentration sensor 692 detects the hydrogen concentration in the vicinity of the injection hole 104 of the hydrogen supply pipe 102 in the hydrogen manifold 261 and outputs a signal to the ECU 15 according to the detected hydrogen concentration.

Next, a method of switching the hydrogen supply destination in the fuel cell system 6 will be described with reference to FIGS. 11 to 14. FIG. 11 shows a flowchart of a method of switching the hydrogen supply destination. The process shown in the flowchart of FIG. 11 is always performed when the fuel cell system 6 is in operation.

When the fuel cell system 6 is operating, the switching valve 60 is in the state shown in FIG. Specifically, the valve member 63 is in a state in which the end surface 638 of the second communication portion 634 is in contact with the end surface 621 of the second housing 62. As a result, since the opening 641 is closed by the end face 621, the hydrogen introduced into the space 602 from the introduction port 611 is supplied with hydrogen through the space 602, the orifice 636, the space 601 and the first outlet port 612. It is supplied to the pipe 101. The hydrogen in the hydrogen supply pipe 101 is injected from the injection hole 103 of the hydrogen supply pipe 101 and is supplied to all the cells 25 included in the fuel cell 1.

First, in step 101 (hereinafter, simply referred to as “S”) 101, the hydrogen concentration of the hydrogen manifold 261 is calculated. In S101, the ECU 15 calculates the hydrogen concentration in the vicinity of the injection hole 104 of the hydrogen supply pipe 102 based on the signal output by the hydrogen concentration sensor 692.

Next, in S102, it is determined whether or not the hydrogen concentration is equal to or less than the threshold value. In S102, the ECU 15 determines whether or not the hydrogen concentration in the vicinity of the injection hole 104 of the hydrogen supply pipe 102 calculated in S101 is equal to or less than a predetermined threshold value. If the hydrogen concentration is equal to or less than a predetermined threshold value, the process proceeds to S103. When the hydrogen concentration is larger than a predetermined threshold value, the process returns to S101 to calculate the hydrogen concentration in the vicinity of the injection hole 104 of the hydrogen supply pipe 102.

When it is determined in S102 that the hydrogen concentration is equal to or less than a predetermined threshold value, the hydrogen supply pressure is changed to the recovery pressure in S103. In S103, the ECU 15 controls the pressure regulating valve 114 and changes the hydrogen supply pressure supplied to the switching valve 60 to a recovery pressure that is larger than the hydrogen pressure in S101. At this time, the hydrogen pressure detected by the pressure detection unit 691 is output to the ECU 15 and fed back to the hydrogen pressure adjustment in the pressure regulating valve 114.

When the hydrogen supply pressure is changed to the recovery pressure, the valve member 63 is affected by the hydrogen pressure acting on the end face 640 as the "first pressure receiving surface" on the second housing 62 side of the first series passage 632. As shown in FIG. 12, the movement in the direction of the first outlet 612 is started against the urging force of the urging member 64. When the valve member 63 starts moving in the direction of the first outlet 612, the end face 638 and the end face 621 are separated from each other, so that hydrogen of recovery pressure flows into the space 603 through the opening 641. As a result, the valve member 63 is accelerated in the direction of the first outlet 612 by the pressure of hydrogen acting on the end surface 638 of the second communication portion 634.

When the valve member 63 further moves in the direction of the first outlet 612 from the position shown in FIG. 12, the space 603 and the second outlet 613 communicate with each other as shown in FIG. As a result, hydrogen in space 603 is supplied to the hydrogen supply pipe 102. The hydrogen supplied to the hydrogen supply pipe 102 is injected from the injection hole 104 toward the cell 25 on the other end side in the stacking direction. On the other hand, when the valve member 63 moves in the direction of the first outlet 612, the contact portion 631 and the edge portion 616 come into contact with each other as shown in FIG. As a result, the space 601 and the first outlet 612 are cut off, so that the supply of hydrogen to the hydrogen supply pipe 101 is stopped.
In this way, when the switching valve 60 is in the state shown in FIG. 13, hydrogen is supplied from the hydrogen supply pipe 102 only to the cell 25 on the other end side in the stacking direction in the fuel cell 10.

Next, in S104, the hydrogen concentration of the hydrogen manifold 261 is calculated. In S104, the ECU 15 calculates the hydrogen concentration in the vicinity of the injection hole 104 of the hydrogen supply pipe 102 based on the signal output by the hydrogen concentration sensor 692. At this time, the hydrogen concentration in the vicinity of the injection hole 104 increases because hydrogen is preferentially supplied by the hydrogen supply pipe 102.

Next, in S105, it is determined whether or not the hydrogen concentration is larger than the threshold value. In S105, the ECU 15 determines whether or not the hydrogen concentration in the vicinity of the injection hole 104 of the hydrogen supply pipe 102 calculated in S104 is greater than a predetermined threshold value. If the hydrogen concentration is greater than a predetermined threshold, the process proceeds to S106. When the hydrogen concentration is equal to or less than a predetermined threshold value, the process returns to S104 to calculate the hydrogen concentration in the vicinity of the injection hole 104 of the hydrogen supply pipe 102.

When it is determined in S105 that the hydrogen concentration is greater than a predetermined threshold value, the hydrogen supply pressure is returned to the original pressure in S106. Here, the "original pressure" is, for example, the pressure of hydrogen in S101. At this time, the hydrogen pressure detected by the pressure detection unit 691 is output to the ECU 15 and fed back to the hydrogen pressure adjustment in the pressure regulating valve 114.
In the fuel cell system 6, the hydrogen supply destination is switched in this way.

In the fuel cell system 6 according to the fifth embodiment, two hydrogen supply pipes 101 and 102 are inserted into the hydrogen manifold 261. The hydrogen supply pipe 101 has an injection hole 103 formed so as to correspond to each position of all the cells 25. Further, the hydrogen supply pipe 102 is formed so as to correspond to the position of the cell 25 on the other end side in the stacking direction including the cell 257. As a result, the fifth embodiment exhibits the effects (a) and (c) of the first embodiment.

Further, the fuel cell system 6 includes a switching valve 60 capable of switching the hydrogen supply destination to the hydrogen supply pipe 101 or the hydrogen supply pipe 102 according to the magnitude of the hydrogen supply pressure. As a result, when hydrogen is supplied to all the cells 25 included in the fuel cell 10, the hydrogen supply pressure at the pressure regulating valve 114 is such that the valve member 63 does not move in the direction of the first outlet 612. The pressure is adjusted and hydrogen is supplied by the hydrogen supply pipe 101. The hydrogen injected from the injection hole 103 of the hydrogen supply pipe 101 goes to each of all the cells 25 of the fuel cell 10 (see the practical arrow F51 in FIG. 14A).
On the other hand, when hydrogen is preferentially supplied to the cell 257 on the other end side in the stacking direction, the pressure of hydrogen is adjusted by the pressure regulating valve 114 so as to be the recovery pressure, as shown in FIG. 14 (b). The valve member 63 is moved in the direction of the first outlet 612. As a result, the introduction port 611 and the second outlet port 613 communicate with each other, so that the hydrogen in the hydrogen tank pipe 111 is supplied to the cell 25 on the other end side in the stacking direction by the hydrogen supply pipe 102 (FIG. 14B). See the practice arrow F52).
As described above, in the fuel cell system 6, the switching valve 60 capable of switching the hydrogen supply destination according to the magnitude of the hydrogen pressure easily transfers hydrogen to the cell 25 on the other end side in the stacking direction in which hydrogen is difficult to spread. Can be supplied. Therefore, the fifth embodiment can increase the output voltage while stabilizing it by controlling the pressure of hydrogen.

Further, the valve member 63 included in the switching valve 60 has an end face 640 of the first communication portion 632 and an end face 638 of the second communication portion 634 on which the pressure of hydrogen acts. When the hydrogen pressure in the internal space 600 first acts on the end face 640 and then the hydrogen pressure acts on the end face 638, which is larger than the area of the end face 640, the movement of the valve member 63 in the direction of the first outlet 612 is accelerated. do. As a result, the supply of hydrogen to the hydrogen supply pipe 101 can be stopped quickly. Therefore, the hydrogen concentration of the cell 25 on the other end side in the stacking direction can be quickly restored, so that the output voltage can be further stabilized.

(Sixth Embodiment)
The fuel cell system according to the sixth embodiment will be described with reference to FIG. In the sixth embodiment, the configuration of the switching valve is different from that in the fifth embodiment.

The fuel cell system according to the sixth embodiment includes a fuel cell 10, a fuel gas flow system 11, a switching valve 70, a pressure detection unit 691, a hydrogen concentration sensor 692, an oxidant gas flow system 12, a cooling system 13, and an ECU 15. ..

The switching valve 70 is provided in the hydrogen tank pipe 111 between the pressure regulating valve 114 and the fuel cell 10. The switching valve 70 switches the hydrogen supply destination to the hydrogen supply pipe 101 or the hydrogen supply pipe 102 according to the pressure of hydrogen flowing through the hydrogen tank pipe 111. As shown in FIG. 15, the switching valve 70 has a first housing 71, a second housing 72, a valve member 73, and an urging member 74.

The first housing 71 is formed in a substantially bottomed cylindrical shape. The first housing 71 has a first outlet 711 and a second outlet 712.
The first outlet 711 is formed at the bottom 713 of the first housing 71. The first outlet 711 is connected to the hydrogen supply pipe 101. The first outlet 711 can derive hydrogen in the internal space 700 "inside the housing" to the hydrogen supply pipe 101.
The second outlet 712 is formed on the radial outer side wall 714 of the first housing 71. The second outlet 712 is connected to the hydrogen supply pipe 102. The second outlet 712 can lead the hydrogen in the internal space 700 to the hydrogen supply pipe 102.

The second housing 72 is a substantially flat plate-shaped member formed so as to close the opening of the first housing 71. The second housing 72 has an introduction port 721.
The introduction port 721 is formed in the switching valve 70 on the side opposite to the first outlet port 711. The introduction port 721 is connected to the hydrogen tank pipe 111. Hydrogen can be introduced into the internal space 700 at the introduction port 721.

The valve member 73 is provided so as to be reciprocally movable in the internal space 700. The valve member 73 has a contact portion 731 and a sliding portion 732.
The contact portion 731 is provided on the side of the first outlet 711 in the internal space 700. The contact portion 731 is formed so as to be able to contact the edge portion 715 on the internal space 700 side of the first outlet 711.
The sliding portion 732 is formed in a substantially columnar shape and is provided on the introduction port 721 side of the contact portion 731. The outer diameter wall surface 733 of the sliding portion 732 is slidably formed on the inner wall surface 716 of the side wall 714 of the first housing 71. As a result, the sliding portion 732 divides the internal space 700 into a space 701 as a "first space" on the first outlet 711 side and a space 702 as a "second space" on the introduction port 721 side.
The valve member 73 has a plurality of orifices 734 formed along the central axis C70 of the switching valve 70. The orifice 734 communicates the space 701 and the space 702.

The urging member 74 is provided in the space 701. One end of the urging member 74 is in contact with the inner wall surface of the bottom 713 of the first housing 71. The other end of the urging member 74 is in contact with the end surface 735 on the bottom 713 side of the contact portion 731. The urging member 74 urges the valve member 73 so that the contact portion 731 and the edge portion 715 are separated from each other. When only the urging force of the urging member 74 acts on the valve member 73, the valve member 73 is in a position to close the opening 717 on the internal space 700 side of the second outlet 712.

In the fuel cell system according to the sixth embodiment, when hydrogen is supplied to all the cells 25 of the fuel cell 10, the switching valve 70 is in the state shown in FIG. Specifically, the contact portion 731 and the edge portion 715 are separated from each other, and the opening 717 of the second outlet 712 is closed by the valve member 73. At this time, the hydrogen introduced into the internal space 700 from the introduction port 721 is supplied to the hydrogen supply pipe 101 through the space 702, the orifice 734 and the space 701.

When the hydrogen concentration detected by the hydrogen concentration sensor 692 becomes equal to or less than a predetermined threshold value, the pressure regulating valve 114 raises the hydrogen pressure to the recovery pressure. As a result, the valve member 73 moves in the direction of the first outlet 711 against the urging force of the urging member 74. When the opening 717 is opened by the movement of the valve member 73, hydrogen is supplied to the hydrogen supply pipe 102 through the opening 717 and the second outlet 712. When the contact portion 731 and the edge portion 715 come into contact with each other, the supply of hydrogen to the hydrogen supply pipe 101 is stopped. As a result, the hydrogen in the hydrogen tank pipe 111 is supplied to the cell 25 on the other end side in the stacking direction by the hydrogen supply pipe 102. Therefore, the sixth embodiment has the same effect as the fifth embodiment.

(Seventh Embodiment)
The fuel cell system according to the seventh embodiment will be described with reference to FIG. In the seventh embodiment, the configuration of the switching valve is different from that in the fifth embodiment.

The fuel cell system according to the seventh embodiment includes a fuel cell 10, a fuel gas flow system 11, a switching valve 80, a pressure detection unit 691, a hydrogen concentration sensor 692, an oxidant gas flow system 12, a cooling system 13, and an ECU 15. ..

The switching valve 80 is provided in the hydrogen tank pipe 111 between the pressure regulating valve 114 and the fuel cell 10. The switching valve 80 switches the hydrogen supply destination to the hydrogen supply pipe 101 or the hydrogen supply pipe 102 according to the pressure of hydrogen flowing through the hydrogen tank pipe 111. As shown in FIG. 16, the switching valve 80 has a first housing 81, a second housing 82, a valve member 83, and an urging member 84.

The first housing 81 is formed in a substantially bottomed cylindrical shape. The first housing 81 has a first outlet 811.
The first outlet 811 is formed at the bottom 812 of the first housing 81. The first outlet 811 is connected to the hydrogen supply pipe 101. The first outlet 811 can lead hydrogen in the internal space 800 as “inside the housing” of the first housing 81 to the hydrogen supply pipe 101.

The second housing 82 is a substantially flat plate-shaped member formed so as to close the opening of the first housing 81. The second housing 82 has an introduction port 821 and a second outlet port 822.
A plurality of introduction ports 821 are formed at positions relatively distant from the central axis C80 of the switching valve 80. The introduction port 821 is connected to the hydrogen tank pipe 111. Hydrogen can be introduced into the internal space 800 of the introduction port 821.
The second outlet 822 is formed in the second housing 82 in the in-diameter direction of the plurality of introduction ports 821. In the present embodiment, the second outlet 822 is formed on the central axis C80. The second outlet 822 is connected to the hydrogen supply pipe 102. The second outlet 822 can derive the hydrogen in the internal space 800 to the hydrogen supply pipe 102.

The valve member 83 is provided so as to be reciprocally movable in the internal space 800. The valve member 83 has a first shaft portion 831, a first contact portion 832, a sliding portion 833, a second shaft portion 834, and a second contact portion 835.
The first shaft portion 831 is a substantially columnar portion provided on the side of the first outlet 811 in the internal space 800. The first shaft portion 831 has an outer diameter smaller than the inner diameter of the first outlet 811.
The first contact portion 832 is a collar-shaped portion provided on the radial outer side of the first shaft portion 831. The first contact portion 832 is formed so as to be able to contact the edge portion 813 on the internal space 800 side of the first outlet 811.

The sliding portion 833 is formed in a substantially columnar shape and is provided on the second housing 82 side of the first shaft portion 831. The outer diameter wall surface 836 of the sliding portion 833 is slidably formed on the inner wall surface 815 of the side wall 814 of the first housing 81. As a result, the sliding portion 833 divides the internal space 800 into a space 801 as a "first space" on the first outlet 811 side and a space 802 as a "second space" on the second outlet 822 side. .. The sliding portion 833 has a plurality of orifices 837 that communicate the space 801 and the space 802.

The second shaft portion 834 is a substantially columnar portion provided on the second housing 82 side of the sliding portion 833. The second shaft portion 834 has an outer diameter smaller than the inner diameter of the second outlet 822 and the outer diameter of the first shaft portion 831.
The second contact portion 835 is a collar-shaped portion provided on the radial outer side of the second shaft portion 834. The second contact portion 835 is formed so as to be able to contact the edge portion 816 on the internal space 800 side of the second outlet 822.

The urging member 84 is provided in the space 801. One end of the urging member 84 is in contact with the inner wall surface of the bottom portion 812 of the first housing 81. The other end of the urging member 84 is in contact with the end surface 838 on the bottom 812 side of the sliding portion 833. The urging member 84 urges the valve member 83 so that the first contact portion 832 and the edge portion 813 are separated from each other and the second contact portion 835 and the edge portion 816 are in contact with each other.

In the fuel cell system according to the seventh embodiment, when hydrogen is supplied to all the cells 25 of the fuel cell 10, the switching valve 80 is in the state shown in FIG. Specifically, the first contact portion 832 and the edge portion 813 are separated from each other, and the opening 823 of the second outlet 822 is closed by the valve member 83. At this time, the hydrogen introduced into the internal space 800 from the introduction port 821 of the switching valve 80 is supplied to the hydrogen supply pipe 101 through the space 802, the orifice 837 and the space 801.

When the hydrogen concentration detected by the hydrogen concentration sensor 692 becomes equal to or less than a predetermined threshold value, the pressure regulating valve 114 raises the hydrogen pressure to the recovery pressure. As a result, the valve member 83 moves in the direction of the first outlet 811 against the urging force of the urging member 84. When the opening 823 is opened by the movement of the valve member 83, hydrogen is supplied to the hydrogen supply pipe 102 through the opening 823 and the second outlet 822. When the first contact portion 832 and the edge portion 813 come into contact with each other, the supply of hydrogen to the hydrogen supply pipe 101 is stopped. As a result, the hydrogen in the hydrogen tank pipe 111 is supplied to the cell 25 on the other end side in the stacking direction by the hydrogen supply pipe 102. Therefore, the seventh embodiment has the same effect as the fifth embodiment.

(Eighth embodiment)
The fuel cell system according to the eighth embodiment will be described with reference to FIG. In the eighth embodiment, the configuration of the switching valve is different from that in the fifth embodiment.

The fuel cell system according to the eighth embodiment includes a fuel cell 10, a fuel gas flow system 11, a switching valve 90, a pressure detection unit 691, a hydrogen concentration sensor 692, an oxidant gas flow system 12, a cooling system 13, and an ECU 15. ..

The switching valve 90 is provided in the hydrogen tank pipe 111 between the pressure regulating valve 114 and the fuel cell 10. The switching valve 90 switches the hydrogen supply destination to the hydrogen supply pipe 101 or the hydrogen supply pipe 102 according to the pressure of hydrogen flowing through the hydrogen tank pipe 111. As shown in FIG. 17, the switching valve 90 has a first housing 91, a second housing 92, a valve member 93, and an urging member 94.

The first housing 91 is formed in the shape of a spherical shell in a hemisphere. The first housing 91 has an introduction port 911 and a second outlet port 912.
The introduction port 911 is formed so that the internal space 900 as "inside the housing" of the first housing 91 and the outside can communicate with each other along the radial direction of the first housing 91. In the present embodiment, the introduction port 911 is formed in the vicinity of the second housing 92 as shown in FIG. The introduction port 911 is connected to the hydrogen tank pipe 111. The introduction port 911 can introduce hydrogen into the internal space 900.
The second outlet 912 is formed at a location different from the introduction port 911 of the first housing 91 so that the internal space 900 and the outside can communicate with each other along the radial direction of the first housing 91. In the present embodiment, the second outlet 912 is formed at a position farther from the second housing 92 than the introduction port 911. The second outlet 912 is connected to the hydrogen supply pipe 102. The second outlet 912 can derive the hydrogen in the internal space 900 to the hydrogen supply pipe 102.

The second housing 92 is formed so as to close the opening of the first housing 91. The second housing 92 has a closing portion 921 and a protruding portion 922.
The closing portion 921 is a substantially flat plate-shaped portion formed so as to close the opening of the first housing 91.
The protruding portion 922 is provided in the closing portion 921 on the side opposite to the introduction port 911 with the valve member 93 interposed therebetween. The projecting portion 922 is formed so as to project from the end surface 923 on the internal space 900 side of the closing portion 921 into the internal space 900. The protrusion 922 has an opening 924 at the end on the internal space 900 side. The end face 925 as the "edge" in which the opening 924 is formed is formed so as to be inclined with respect to the end face 923.
The second housing 92 has a first outlet 926 that communicates the internal space 900 with the outside through the opening 924. The first outlet 926 is connected to the hydrogen supply pipe 101. The first outlet 926 can derive the hydrogen in the internal space 900 to the hydrogen supply pipe 101.

The valve member 93 is provided so as to be movable in the internal space 900. The valve member 93 has a rotating shaft 931, an extension portion 932, and a sliding portion 933.
The rotary shaft 931 is rotatably provided on the closing portion 921.
The extension portion 932 is formed so as to extend in the radial direction of the first housing 91 from the rotating shaft 931 to the inner wall surface 913 of the first housing 91. The extension 932 has a plurality of orifices 934.
The sliding portion 933 is formed along the inner wall surface 913 of the first housing 91 from the end portion of the extension portion 932 opposite to the side connected to the rotating shaft 931. The wall surface 935 of the sliding portion 933 is slidably formed on the inner wall surface 913. As a result, the internal space 900 is divided into a space 901 as a "first space" on the first outlet 926 side and a space 902 as a "second space" on the second outlet 912 side. Space 901 and space 902 are communicated with each other by an orifice 934.
The valve member 93 is rotatably provided as shown by the white arrow F81 shown in FIG. 17 while sliding on the inner wall surface 913 of the first housing 91 with the rotation shaft C90 of the rotation shaft 931 as the center of rotation.

The urging member 94 is provided so as to connect the second housing 92 and the valve member 93. The urging member 94 is a so-called winding spring, and urges the valve member 93 to rotate counterclockwise in FIG. When only the urging force of the urging member 94 is acting on the valve member 93, in the valve member 93, as shown in FIG. 17, the sliding portion 933 opens the opening 914 on the internal space 900 side of the second outlet 912. It is in a position to block.

In the fuel cell system according to the eighth embodiment, when hydrogen is supplied to all the cells 25 of the fuel cell 10, the switching valve 90 is in the state shown in FIG. Specifically, in the valve member 93, the sliding portion 933 closes the opening 914 of the second outlet 912. At this time, the hydrogen introduced into the internal space 900 from the introduction port 911 of the switching valve 90 is supplied to the hydrogen supply pipe 101 through the space 902, the orifice 934 and the space 901.

When the hydrogen concentration detected by the hydrogen concentration sensor 692 becomes equal to or less than a predetermined threshold value, the pressure regulating valve 114 raises the hydrogen pressure to the recovery pressure. As a result, the valve member 93 rotates clockwise against the urging force of the urging member 94. When the valve member 93 rotates clockwise to open the opening 914, hydrogen is supplied to the hydrogen supply pipe 102 through the opening 914 and the second outlet 912. Further, as shown by the dotted line VL93 shown in FIG. 17, when the end surface 936 of the extension portion 932 of the valve member 93 comes into contact with the end surface 925 of the protrusion 922, the opening 924 is closed. As a result, the supply of hydrogen to the hydrogen supply pipe 101 is stopped, and the hydrogen in the hydrogen tank pipe 111 is supplied to the cell 25 on the other end side in the stacking direction by the hydrogen supply pipe 102. Therefore, the eighth embodiment has the same effect as the fifth embodiment.

(Other embodiments)
In the above embodiment, the "fuel gas" is hydrogen and the "oxidizer gas" is air. However, the fuel gas and the oxidant gas are not limited to this. It suffices if electric energy can be generated by the reaction between the fuel gas and the oxidant gas.

In the first to fourth embodiments, three hydrogen supply pipes are provided. In the fifth to eighth embodiments, two hydrogen supply pipes are provided. However, the number of hydrogen supply pipes provided is not limited to this. A plurality of hydrogen supply pipes may be provided, and one of the hydrogen supply pipes may be provided so as to be able to supply hydrogen to the cell located on the other end side in the stacking direction.

In the first embodiment, it is assumed that each of the three hydrogen supply pipes is formed so that the lengths at which the injection holes are formed are substantially the same. However, the length at which the injection holes are formed may be different.

In the second embodiment, the number of hydrogen concentration sensors is assumed to be six, three are provided in the hydrogen manifold that supplies hydrogen to the cell, and three are provided in the hydrogen manifold through which hydrogen discharged from the cell flows. .. However, the number and installation location of hydrogen concentration sensors are not limited to this.

In the first to third embodiments, hydrogen is allowed to flow through the three hydrogen supply pipes. However, it is not necessary to flow hydrogen through all three. The gas flow rate of the hydrogen supply pipe capable of supplying hydrogen to the central cell may be set to 0, and the gas may flow only through the hydrogen supply pipe capable of supplying hydrogen to both ends in the stacking direction. Further, in a normal state where the output voltages of the cells at both ends in the stacking direction are not a problem, a gas flow rate corresponding to the number of cells may be flowed.

In the fourth embodiment, the hydrogen supply pipe capable of supplying hydrogen to the cell substantially in the center of the stacking direction has a double structure of an outer pipe and an inner pipe. However, other hydrogen supply pipes may also have a double structure. Further, the outer tube may be provided so as to be rotatable with respect to the inner tube.

The fuel cells of the first to fourth embodiments may be applied to the fuel cell system of the fifth to eighth embodiments.

In the fifth to eighth embodiments, the hydrogen supply pressure is changed based on the hydrogen concentration in the hydrogen manifold detected by the hydrogen concentration sensor. However, the criteria for changing the hydrogen supply pressure are not limited to this. The hydrogen supply pressure may be changed based on the physical quantity of hydrogen detected by the “physical quantity detection unit”.

As described above, the present invention is not limited to such embodiments, and can be implemented in various embodiments without departing from the spirit of the invention.

1,2,3,10 ... Fuel cell 101,21,22,36,37,42 ... Hydrogen supply pipe (fuel gas supply pipe)
102, 23, 38 ... Hydrogen supply pipe (fuel gas supply pipe, first fuel gas supply pipe)
25, 255, 256 ... cell 257 ... cell (other end cell)
260 ... Hydrogen flow path (fuel gas flow path)
261 ... Hydrogen manifold (fuel gas manifold)
5, 6 ... Fuel cell system

Claims (10)

A plurality of cells (25) that are formed so as to be able to generate electric energy by the reaction of the fuel gas and the oxidant gas and are stacked along one direction, and
A fuel gas manifold (261) that communicates with the fuel gas flow path (260) of each of the plurality of cells and is capable of flowing fuel gas.
A plurality of fuel gas supply pipes (101,) housed in the fuel gas manifold, formed so as to extend along the one direction from one end side of the one direction of the plurality of cells, and capable of supplying fuel gas to the cells. 102,21,22,23) and
A fuel gas concentration detection unit (361, 362, 371, 372, 381, 382) capable of detecting the concentration of fuel gas flowing through the fuel gas flow path, and
With
The first fuel gas supply pipes (23, 102) of the plurality of fuel gas supply pipes can supply fuel gas to the other end side cells (257) located on the other end side of the plurality of cells in one direction. Tei Ru fuel cell provided. A plurality of cells (25) that are formed so as to be able to generate electric energy by the reaction of the fuel gas and the oxidant gas and are stacked along one direction, and
A fuel gas manifold (261) that communicates with the fuel gas flow path (260) of each of the plurality of cells and is capable of flowing fuel gas.
A plurality of fuel gas supply pipes (101,) housed in the fuel gas manifold, formed so as to extend along the one direction from one end side of the one direction of the plurality of cells, and capable of supplying fuel gas to the cells. 102,21,22,23,36,37,38,42),
With
The fuel gas supply pipe has a plurality of injection holes (210, 220, 230, 360, 370, 380, 423, 426, 103, 104) capable of injecting fuel gas toward each of the plurality of cells. ,
The first fuel gas supply pipes (23, 38, 102) of the plurality of fuel gas supply pipes supply fuel gas to the other end side cells (257) located on the other end side of the plurality of cells in one direction. to be able to Tei Ru fuel cell provided. The fuel cell according to claim 2, wherein the plurality of injection holes are formed so that the inner diameter increases as the distance from one end side of the plurality of cells in one direction increases. The second fuel gas supply pipes (36) of the plurality of fuel gas supply pipes are provided so as to be able to supply fuel gas to one end side cells (255) located on one end side in the one direction of the plurality of cells.
The number of the injection holes of the first fuel gas supply pipe or the number of the injection holes of the second fuel gas supply pipe is the number of the first fuel gas supply pipe and the second of the plurality of fuel gas supply pipes. The fuel cell according to claim 2 or 3, wherein the number of injection holes is smaller than that of the fuel gas supply pipe (37) other than the fuel gas supply pipe. The fuel gas supply pipe includes an outer pipe (421) having an outer injection hole (423) as the injection hole on the radial outer side of the injection hole, and a center of the outer pipe on the radial inner side of the outer pipe. Claims having an inner tube (422) having an inner injection hole (426) as the injection hole that is coaxial with the shaft (C42) and is rotatably provided relative to the outer tube and can communicate with the outer injection hole. The fuel cell according to any one of 2 to 4. The fuel according to any one of claims 2 to 5, further comprising a fuel gas concentration detecting unit (361, 362, 371, 372, 381, 382) capable of detecting the concentration of the fuel gas flowing through the fuel gas flow path. battery. A pressure regulator (114) that can adjust the pressure of the fuel gas supplied by the fuel gas tank,
A switching valve (60, 70, 80, 90) provided between the pressure adjusting unit and the plurality of fuel gas supply pipes and capable of switching the fuel gas supply destination according to the fuel gas pressure.
The fuel cell according to any one of claims 1 to 5.
A physical quantity detecting unit (691, 692) that is provided so as to be able to detect the physical quantity of the fuel gas whose pressure is controlled by the pressure adjusting unit and can output a signal corresponding to the physical quantity.
A control unit (15) that is electrically connected to the pressure adjusting unit and the physical quantity detecting unit and controls the operation of the pressure adjusting unit based on a signal output by the physical quantity detecting unit.
Fuel cell system with. The physical quantity detecting unit can detect the concentration of the fuel gas in the fuel gas manifold, and can detect the concentration of the fuel gas.
The control unit controls the operation of the pressure adjusting unit so as to increase the pressure of the fuel gas when the concentration of the fuel gas detected by the physical quantity detecting unit is equal to or less than the threshold value.
The fuel cell system according to claim 7, wherein the switching valve switches the fuel gas supply destination to the first fuel gas supply pipe. The switching valve is
A first outlet (612,711,811,926) capable of communicating with fuel gas supply pipes other than the first fuel gas supply pipe of the plurality of fuel gas supply pipes, and communication with the first fuel gas supply pipe. With a housing (61,62,71,72,81,82,91,92) having a possible second outlet (613,712,922,912),
The first space (601,701,801,901) and the second guide are provided so as to be reciprocally movable in the housing (600, 700, 800, 900) and can communicate with the first outlet in the housing. It is separably formed in a second space (603, 702, 802, 902) that can communicate with the outlet, and has an orifice (636,734,837,934) that communicates the first space and the second space. A valve member (63, 73, 83, 93) capable of contacting the inner edge of the housing (616,715,816,925) of the first outlet, and a valve member (63, 73, 83, 93).
The fuel cell system according to claim 7 or 8. The valve member has a first pressure receiving surface (640) on which the fuel gas pressure acts and a second pressure receiving surface on which the area on which the fuel gas pressure acts is larger than the area on which the fuel gas pressure acts on the first pressure receiving surface. Has (638) and
The fuel cell system according to claim 9, wherein the pressure of the fuel gas acts on the first pressure receiving surface and then the pressure of the fuel gas acts on the second pressure receiving surface.

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