JP2002231294A - Fuel cell device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the residence of condensate by optimizing the vertical positional relationship among the respective parts of a hydrogen circulating system. SOLUTION: This device is provided with an ejector pump 13 for mixing an exhaust fuel from a fuel outlet 3b of a fuel cell 1 with a raw fuel to feed the gaseous mixture to an fuel inlet 3a. A passage shut-off valve 19 between the fuel outlet 3b and an exhaust fuel inlet 13b of the ejector pump 13 is disposed higher than the exhaust fuel inlet 13b, an exhaust side water separator 17 between the fuel outlet 3b and the shut-off valve 19 is disposed lower than the fuel outlet 3b and the shut-off valve 19, a purge pipe 25 for purging the exhaust fuel gas outside is connected to a pipe 21 on the upstream side of the shut-off valve 19 at a purge branch part 23, a purge gas shut-out valve 27 on the purge pipe 25 is disposed higher than the branch part 23, and a feeding-side water separator 15 mounted on the downstream side of a mixed fuel outlet 13a of the ejector pump 13 is disposed lower than the outlet 13a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a fuel circulating means for mixing raw fuel and exhaust fuel discharged from a fuel outlet of a fuel electrode in a fuel cell and circulating the mixed fuel to a fuel inlet of the fuel electrode. To a fuel cell device.

[0002]

2. Description of the Related Art In recent years, attention has been paid to a fuel cell technology capable of achieving clean exhaust and high energy efficiency with respect to environmental problems, in particular, air pollution caused by automobile exhaust gas and global warming caused by carbon dioxide. . Fuel cells supply hydrogen as a fuel or hydrogen-rich reformed gas and air as an oxidizing agent, for example, to a polymer membrane-electrocatalyst composite, causing an electrochemical reaction to convert chemical energy into electric energy. It is a conversion system. Among them, a solid polymer electrolyte fuel cell having a particularly high output density has attracted attention as a power source for a mobile body such as an automobile.

In a polymer electrolyte fuel cell using a polymer electrolyte membrane as an electrolyte, an anode electrode (fuel electrode) to which hydrogen serving as a fuel is supplied and air serving as an oxidant are supplied to the electrolyte membrane. It is configured to be arranged between a cathode electrode (oxidant electrode). When hydrogen is supplied to the fuel electrode, it is dissociated into hydrogen ions and electrons, the hydrogen ions pass through the electrolyte membrane, and the electrons generate electric power through an external circuit and move to the oxidant electrode.

On the other hand, at the oxidant electrode, oxygen in the supplied air reacts with the hydrogen ions and the electrons to generate water, which is discharged to the outside.

[0005] In such a fuel cell device, hydrogen not used for power generation at the fuel electrode is recirculated and mixed with hydrogen of raw fuel, and this mixed fuel is supplied to the fuel electrode. . For example, in Japanese Patent Application Laid-Open No. Hei 9-213353, excess hydrogen discharged from the fuel electrode is returned to an ejector pump via a recirculation gas circuit, and the returned excess hydrogen and a high concentration of hydrogen separately introduced into the ejector pump are high. The mixed fuel mixed with the raw fuel is supplied to the fuel electrode.

The recirculation gas circuit includes a heat exchanger for cooling the exhaust gas, which is provided with a tank for storing condensed and liquefied product water from the fuel outlet side of the fuel electrode to the ejector pump, and a load for the fuel cell. A recirculation gas flow control valve for adjusting the flow rate of the recirculation gas accordingly is provided in order. Further, a gas purge circuit is provided between the heat exchanger and the recirculation gas flow control valve.

[0007]

By the way, in the above-mentioned conventional fuel cell device, a recirculation gas flow control valve, a gas purge pipe, and the like are arranged in a recirculation gas circuit from the fuel cell. , Especially the top and bottom, is not taken into account.
Depending on the vertical arrangement, condensed water accumulates in the recirculation gas flow control valve, and a predetermined amount of hydrogen cannot be supplied to the fuel cell.
In addition, condensed water accumulates in the gas purge pipe, and a predetermined purge flow rate cannot be obtained during the purge control, so that stable control cannot be performed and controllability is deteriorated.

Accordingly, an object of the present invention is to prevent stagnation of condensed water by optimizing the vertical position of each part in the recirculation gas circuit.

[0009]

According to a first aspect of the present invention, there is provided a fuel cell comprising: mixing raw fuel with exhaust fuel discharged from a fuel outlet of a fuel electrode in a fuel cell; In a fuel cell device provided with a fuel circulating means for circulating a fuel at a fuel inlet of the fuel electrode, a flow path shutoff valve is provided in a pipe between a fuel outlet of the fuel electrode and a discharged fuel inlet of the fuel circulating means. The shut-off valve is arranged at a position higher than a discharge fuel inlet of the fuel circulation means.

In a second aspect of the present invention, in the first aspect, the fuel supplied to the fuel cell is humidified.

According to a third aspect of the present invention, in the configuration of the first or second aspect of the invention, a fuel discharge-side water separation device separates water in the discharged fuel into a pipe between the fuel outlet of the fuel electrode and the flow path cutoff valve. Means is provided, and the fuel discharge side water separating means is arranged at a position lower than the fuel outlet and the flow path cutoff valve.

According to a fourth aspect of the present invention, in the configuration of any one of the first to third aspects of the present invention, a purge pipe for discharging discharged fuel to the outside is connected to a pipe on the upstream side of the flow path cutoff valve. And a purge gas cutoff valve is provided in the purge pipe, and the purge gas cutoff valve is arranged at a position higher than the purge branch portion.

According to a fifth aspect of the present invention, in the configuration of any one of the first to fourth aspects of the present invention, a fuel supply-side water separating means is provided in a pipe connected to the mixed fuel outlet of the fuel circulating means. The mixed fuel inlet of the side moisture separating means is arranged at a position lower than the mixed fuel outlet of the fuel circulating means.

According to a sixth aspect of the present invention, in the configuration of any one of the first to fifth aspects, a plurality of pipes connected to the fuel inlet of the fuel cell are provided in parallel, and a fuel circulation means is provided in each of the parallel pipes. In addition, a plurality of pipes connected to the fuel outlet of the fuel cell are provided in parallel, and a flow path cutoff valve is provided in each of the parallel pipes.

According to a seventh aspect of the present invention, in the configuration of the sixth aspect of the present invention, the plurality of fuel circulating means have different circulating flow characteristics, and accordingly, the flow path diameter of each parallel pipe connected to each fuel circulating means. Also has a different configuration.

According to an eighth aspect of the present invention, in the configuration of the seventh aspect of the present invention, a junction between a plurality of parallel pipes connected to the fuel inlet of the fuel cell and a parallel pipe connected to the fuel outlet of the fuel cell are provided. The configuration is such that a pipe having a small diameter on the small flow rate side is arranged to be closer to a vertical state than a pipe having a large diameter on the large flow rate side with respect to at least one of the mutual branch portions.

According to a ninth aspect of the present invention, in the configuration of the eighth aspect, the inclination angle of the straight pipe having the small diameter on the small flow rate side with respect to the horizontal plane is larger than that of the straight pipe having the large diameter on the large flow rate side. It is configured to be larger than the same inclination angle.

According to a tenth aspect of the present invention, in the configuration of the eighth aspect, the radius of curvature of the curved pipe having the small diameter on the small flow rate side is changed to the radius of curvature of the curved pipe having the large diameter on the large flow rate side. It is configured to be smaller.

The invention according to claim 11 is the invention according to claims 7 to 10
In any one of the aspects of the invention, at least one of the merging portion and the branch portion of the parallel pipes is provided with a throttle on the large-diameter pipe.

The invention of claim 12 is the invention of claims 1 to 11
In the configuration of any one of the inventions, the raw fuel inlet of the fuel circulating means is arranged at a position higher than the mixed fuel outlet, and the discharged fuel inlet of the fuel circulating means is connected to the discharged fuel inlet and the fuel in the fuel circulating means. It is configured to be arranged at a position higher than the junction with the passage.

[0021]

According to the first aspect of the present invention, a flow path cutoff valve provided in a pipe between a fuel outlet of a fuel electrode of a fuel cell and a discharged fuel inlet of a fuel circulating means is provided for discharging the fuel circulating means. Since it is arranged at a position higher than the fuel inlet, the stagnation of condensed water in the flow path cutoff valve can be prevented, and fuel can be appropriately supplied from the fuel circulation means to the fuel electrode.

According to the second aspect of the invention, it is possible to prevent the humidification water for humidifying the fuel from remaining in the flow path shutoff valve, and to appropriately supply the fuel from the fuel circulation means to the fuel electrode. be able to.

According to the third aspect of the present invention, the fuel discharge side water separating means provided in the pipe between the fuel outlet of the fuel cell and the flow path cutoff valve is located at a position lower than the fuel outlet and the flow path cutoff valve. Since the condensed water is disposed, the condensed water efficiently accumulates in the water separating means on the fuel discharge side, so that the condensed water can be prevented from staying in the flow path cutoff valve, and the fuel can be appropriately supplied from the fuel circulating means to the fuel electrode.

According to the fourth aspect of the present invention, a purge branch for connecting a purge pipe for discharging discharged fuel to the outside is provided in the pipe on the upstream side of the flow path cutoff valve, and the purge gas cutoff valve provided in the purge pipe is provided. Is located at a position higher than the purge branch portion, so that condensed water can be prevented from staying in the purge gas shutoff valve,
The purge gas operation can be performed properly, and the fuel can be properly supplied from the fuel circulation means to the fuel electrode.

According to the fifth aspect of the present invention, the mixed fuel inlet of the fuel supply side water separating means provided on the pipe connected to the mixed fuel outlet of the fuel circulating means is positioned lower than the mixed fuel outlet of the fuel circulating means. Therefore, the condensed water flows efficiently to the fuel supply-side water separating means without staying in the pipe, and the fuel can be appropriately supplied from the fuel circulating means to the fuel electrode.

According to the invention of claim 6, in a fuel cell apparatus having a plurality of fuel circulation circuits having a plurality of fuel circulation means and a flow path cutoff valve, the condensed water is supplied to each flow path cutoff valve. Stagnation can be prevented, and fuel can be properly supplied from each fuel circulation means to the fuel electrode.

According to the seventh aspect of the present invention, the plurality of fuel circulating means have different circulating flow characteristics from each other, and accordingly, the diameter of each pipe connected to each fuel circulating means is also different. In addition, the accumulation of the condensed water in each flow path shutoff valve can be prevented, and the fuel can be appropriately supplied from each fuel circulation means to the fuel electrode.

According to the invention of claim 8, at least one of a junction between the plurality of parallel pipes connected to the fuel inlet of the fuel cell and a branch between the parallel pipes connected to the fuel outlet of the fuel cell. On the other hand, the small-diameter pipe on the small flow rate side is arranged so as to be closer to the vertical than the large-diameter pipe on the large flow rate side, so the condensed water tends to stay in the small-diameter pipe. Of the condensed water can be prevented, and the fuel can be properly supplied from the fuel circulation means to the fuel electrode.

According to the ninth aspect of the present invention, the inclination angle of the small-diameter straight pipe on the small flow rate side with respect to the horizontal plane is larger than the inclination angle of the large-diameter straight pipe on the large flow rate side. In addition, the accumulation of the condensed water in the small-diameter pipe in which the condensed water is easily accumulated can be suppressed, and the fuel can be appropriately supplied from the fuel circulation means to the fuel electrode.

According to the tenth aspect of the present invention, the radius of curvature of the small-diameter curved pipe on the small flow rate side is made smaller than the radius of curvature of the large-diameter curved pipe on the large flow rate side, thereby achieving a more vertical Therefore, the condensed water can be prevented from staying in the small-diameter pipe in which the condensed water easily stays, and the fuel can be appropriately supplied from the fuel circulation means to the fuel electrode.

According to the eleventh aspect of the present invention, a throttle is provided in at least one of the large-diameter side of the junction and the branch of the parallel pipes. As a result, condensed water is sucked from the small-diameter pipe on the small flow rate side to the large-diameter pipe on the large flow rate side. The fuel can be appropriately supplied to the fuel electrode.

According to the twelfth aspect of the invention, the raw fuel inlet of the fuel circulating means is arranged at a position higher than the mixed fuel outlet, and the discharged fuel inlet of the fuel circulating means is connected to the discharged fuel inlet and the fuel circulating means. Since it is arranged at a position higher than the junction with the fuel passage, the accumulation of condensed water in the fuel circulation means can be prevented, and fuel can be appropriately supplied from the fuel circulation means to the fuel electrode.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings.

FIG. 1 is an overall configuration diagram of a fuel cell device according to a first embodiment of the present invention. Reference numeral 1 denotes a fuel cell structure in which a fuel electrode 3 and an oxidant electrode 5 are arranged to face each other with a solid polymer electrolyte membrane (not shown) interposed therebetween. It is a configured fuel cell stack (hereinafter simply referred to as a fuel cell). 7
Denotes a humidifier, in which the fuel gas and the oxidizing gas are adjacent to the pure water through the semipermeable membrane, respectively, and the water molecules pass through the semipermeable membrane to humidify the fuel gas and the oxidizing gas. Things.

In this embodiment, hydrogen is used as fuel and air is used as oxidant. After the hydrogen stored in the hydrogen tank 9 is regulated by the fuel pressure regulating valve 11, the hydrogen is supplied to the ejector pump 13 as fuel circulation means, the supply water separator 15 as fuel supply water separation means, and the humidifier 7. As described above, the fuel is supplied to the fuel cell 1 from the fuel inlet 3a of the fuel electrode 3.

The mixed gas of hydrogen and water vapor discharged from the fuel outlet 3b of the fuel electrode 3 passes through the discharge water separator 17 as fuel discharge water separation means, the flow path shutoff valve 19, and the ejector pump. At 13, the fuel gas is mixed with the raw fuel gas, and the mixed gas is circulated to the fuel electrode 3 of the fuel cell 1 through the above-described supply-side water separator 15 and humidifier 7.

The discharge-side water separator 17 and the flow path shutoff valve 1
A purge pipe 25 for purging hydrogen is branched and connected to a pipe 21 between the pipe 9 and a purge branch section 23. The purge pipe 25 is provided with a purge gas cutoff valve 27 and a purge gas catalyst 29.

The air as the oxidizing agent is supplied to the compressor 31
The fuel is supplied from the oxidizer inlet 5a to the oxidizer electrode 5 of the fuel cell 1 through the humidifier 7 described above. The exhaust gas discharged from the oxidant outlet 5b of the oxidant electrode 5 contains water vapor and liquid water, and the liquid separator 33 separates the liquid water. The water separator 33 is provided with an air purge pipe 35 and a purge gas cutoff valve 37 for supplying air during the above-described hydrogen purging. At the time of hydrogen purging, air is supplied to the purge gas catalyst 29 and discharged to the outside. An air discharge pipe 39 is branched and connected to the air purge pipe 35, and the air discharge pipe 39 is provided with an air pressure regulating valve 41.

The control unit (not shown) receives a detection signal from a sensor (not shown) that detects the power generation state of the fuel cell 1 and, based on the power generation state, determines the hydrogen pressure and the air pressure based on the detection values of the sensor (not shown). Feedback control is performed so as to be adjusted by the fuel pressure control valve 11 and the air pressure control valve 41, and feedback control is performed so that the air flow rate is adjusted by the rotation speed of the compressor 31 based on a detection value of a sensor (not shown).

FIG. 2 shows the upper and lower positional relationships of the respective components of the hydrogen circulation system in the fuel cell device having the above-described configuration. The hydrogen stored in the hydrogen tank 9 is regulated to a predetermined pressure by the fuel pressure regulating valve 11 as described above, and then mixed with the hydrogen discharged and circulated from the fuel cell 1 by the ejector pump 13 to be supplied. It is sent to the side water separator 15.

At this time, the mixed fuel inlet 15 a of the supply-side water separator 15 is connected to the mixed fuel outlet 13 of the ejector pump 13.
a. In this case, in FIG. 2, the pipe 43 connecting the ejector pump 13 and the supply-side water separator 15 is curved, but may be arranged linearly and inclined. When the fuel cell device is mounted on a vehicle with the pipe 43 being straight, the inclination angle of the pipe 43 is set to 50 degrees to 90 degrees with respect to the horizontal plane H in consideration of the inclination and acceleration of the vehicle. It is desirable. Note that this inclination angle does not necessarily have to be constant from the ejector pump 13 to the supply-side water separator 15.

With this arrangement, the water condensed between the ejector pump 13 and the supply-side water separator 15 does not accumulate in the pipe 43.
The flow of hydrogen is not hindered by water, so that the supply of hydrogen to the fuel cell 1 can be properly performed, and the controllability of the control unit can be prevented from deteriorating.

The hydrogen exiting the feed-side water separator 15 is supplied to the humidifier 7
To the fuel electrode 3 of the fuel cell 7 from the fuel inlet 3a. The mixed gas of hydrogen and steam flowing out of the fuel outlet 3b of the fuel electrode 3 passes through the discharge-side water separator 17, and the flow path shutoff valve 1
Flowing to 9.

At this time, the inlet 17 of the discharge-side water separator 17
a is disposed at a position lower than the fuel outlet 3b of the hydrogen electrode 3, and the outlet 17b of the discharge-side water separator 17 is disposed at a position lower than the flow path shutoff valve 19. in this case,
In FIG. 2, a pipe 45 connecting the fuel cell 1 and the discharge-side water separator 17, and the discharge-side water separator 17 and the flow path shutoff valve 1
The pipe 21 connecting to the pipe 9 has a curved shape, but may be arranged linearly and inclined. Piping 4
When the fuel cell device is mounted on a vehicle with the straight lines 5 and 21 mounted, the inclination angles of the pipes 45 and 21 are set to 5 degrees with respect to the horizontal plane H in consideration of the inclination of the vehicle and acceleration.
It is desirable that the angle be 0 degrees to 90 degrees. Note that this inclination angle may not be constant from the fuel cell 1 to the discharge water separator 17 or from the discharge water separator 17 to the flow path shutoff valve 19.

With this arrangement, the piping 45
The water condensed in the fuel cell 1 and 21 efficiently flows down to the water separator 17 on the discharge side, so that the backflow of water to the fuel cell 1 can be prevented, and the water in the pipes 45 and 21 stays in the closed state and the valve is closed. The stagnation of water in the flow path shutoff valve 19 can be prevented. Thus, the flow of hydrogen when the flow path shutoff valve 19 is opened is not hindered by water, and the supply of hydrogen to the fuel cell 1 can be properly performed, and the controllability of the control unit is prevented from deteriorating. Can be.

After that, hydrogen is supplied from the flow path cutoff valve 19 to the ejector pump 13, and the ejector pump 13
It is mixed with the raw fuel gas supplied through the fuel pressure regulating valve 11 and circulated to the fuel cell 1 side.

At this time, the flow path cutoff valve 19 is arranged at a position higher than the discharge fuel inlet 13 b of the ejector pump 13. In this case, in FIG. 2, the pipe 49 connecting the flow path cutoff valve 19 and the ejector pump 13 has a curved shape, but may be arranged linearly and inclined. When the fuel cell device is mounted on a vehicle with the pipe 49 being straight, the inclination angle of the pipe 49 should be 50 to 90 degrees with respect to the horizontal plane H in consideration of the inclination of the vehicle and acceleration.
Degree is desirable. Note that this inclination angle may not be constant from the flow path cutoff valve 19 to the ejector pump 13.

By arranging in this way, backflow of water condensed between the flow path cutoff valve 19 and the ejector pump 13 to the flow path cutoff valve 19 is prevented, and the flow path cutoff section 19 in the closed state is prevented. Water can be prevented from staying in
The stagnation of water in the inside 9 can also be prevented. Thereby, the flow of hydrogen when the flow path cutoff valve 19 is opened is not hindered by water, and the supply of hydrogen can be appropriately performed, and deterioration of controllability by the control unit can be prevented.

Further, the pipe 21 downstream of the discharge-side water separator 17
Flows through the purge branch section 23 into the purge pipe 25, flows through the purge gas cutoff valve 27, is supplied to the purge gas catalyst 29, and is discharged to the outside.

At this time, the purge gas cutoff valve 27 is arranged at a position higher than the purge branch portion 23. in this case,
In FIG. 2, the purge pipe 25 connecting the purge gas cutoff valve 27 and the purge branch portion 23 has a curved shape.
You may make it arrange incline as a linear shape. When the fuel cell device is mounted on a vehicle with the purge pipe 25 being straight, the inclination angle of the purge pipe 25 should be 50 degrees or less with respect to the horizontal plane H in consideration of the inclination and acceleration of the vehicle.
It is desirable that the angle be 90 degrees. In addition, this inclination angle is
From the purge gas cutoff valve 27 to the purge branching section 23, it does not have to be constant.

By arranging in this manner, backflow of water condensed between the purge branch section 23 and the purge gas cutoff valve 27 to the purge branch section 23 is prevented, and the purge gas cutoff valve 27 in the closed state is prevented from flowing. Of water in the purge pipe 25 can be prevented.
Thus, the flow of the purge gas when the purge gas cutoff valve 27 is opened is not hindered by the water, and the controllability of the control unit can be prevented from deteriorating.

FIG. 3 is an overall configuration diagram of a fuel cell device showing a second embodiment of the present invention. In this embodiment, an ejector pump 130 is additionally provided in parallel with the ejector pump 13 in the first embodiment. Correspondingly, the fuel pressure regulating valve 110 is connected to the fuel pressure regulating valve 11 and the flow path is shut off. A flow path cutoff valve 190 is additionally provided in parallel with the valve 19. Other configurations are the same as those shown in FIG. 1, and the same components as those in FIG. 1 are denoted by the same reference numerals. In addition, the ejector pump, the fuel pressure regulating valve, and the flow path shutoff valve may have a configuration in which three or more are all provided in parallel.

FIG. 4 shows the upper and lower positional relationships of the components of the hydrogen circulation system in the fuel cell device having the configuration shown in FIG. The ejector pump 130 and the pipe 43 are connected at a junction 51 by a pipe 53 parallel to the pipe 51. At this time, the junction 51 is disposed at a position lower than the mixed fuel outlet 130a of the ejector pump 130. Have been.

In this case, the pipe 53 connecting the ejector pump 130 and the junction 51 may be curved or straight, but when it is straight, the inclination angle with respect to the horizontal plane H is:
As in the case of the pipe 43, when the fuel cell device is mounted on a vehicle, the fuel cell device is set at 50 degrees to 50 degrees in consideration of the inclination and acceleration of the vehicle.
It is desirable that the angle be 90 degrees. In addition, this inclination angle is
It does not necessarily have to be constant from the ejector pump 130 to the branch portion 51.

With this arrangement, the water condensed between the ejector pump 130 and the branch portion 51 does not accumulate in the pipe 53, so that the flow of hydrogen is not hindered by the water. Hydrogen can be appropriately supplied, and deterioration of controllability by the control unit can be prevented.

The flow path cutoff valve 190 and the pipe 21
The branch 55 is connected by a pipe 57 parallel to the pipe 21 at this time.
It is located at a lower position. In this case, in FIG.
Piping 57 for connecting the branch portion 55 and the flow path cutoff valve 190
Has a curved shape, but may be arranged linearly and inclined. When the fuel cell device is mounted on a vehicle with the pipe 57 being straight, the inclination angle of the pipe 57 is set to 50 to 90 degrees with respect to the horizontal plane H in consideration of the inclination of the vehicle and acceleration. It is desirable. Note that this inclination angle may not be constant from the branch portion 55 to the flow path shutoff valve 190.

With this arrangement, the piping 57
Since the water condensed inside flows down to the branch portion 55 efficiently, it is possible to prevent water from staying in the pipe 57 and water from staying in the flow path shutoff valve 190 in a closed state. Accordingly, the flow of hydrogen when the flow path cutoff valve 190 is opened is not hindered by water, and the supply of hydrogen can be appropriately performed, so that the controllability of the control unit can be prevented from deteriorating.

Further, the flow path cutoff valve 190 and the ejector pump 130 are connected by a pipe 59, and this pipe 59
The flow path cutoff valve 190 is set to be disposed at a position higher than the discharge fuel inlet 130b of the ejector pump 130. In this case, in FIG. 2, the pipe 59 connecting the flow path cutoff valve 190 and the ejector pump 130 has a curved shape, but may be arranged linearly and inclined. When the fuel cell device is mounted on a vehicle with the pipe 59 formed in a straight line, the inclination angle of the pipe 59 should be 50 to 90 degrees with respect to the horizontal plane H in consideration of the inclination and acceleration of the vehicle.
Degree is desirable. Note that this inclination angle may not be constant from the flow path cutoff valve 190 to the ejector pump 130.

By arranging in this manner, backflow of water condensed between the flow path cutoff valve 190 and the ejector pump 130 to the flow path cutoff valve 190 is prevented, and the flow path cutoff section 190 in a closed state is prevented. Of the water in the pipe 59 and the water in the pipe 59 can also be prevented. Accordingly, the flow of hydrogen when the flow path cutoff valve 190 is opened is not hindered by water, and the supply of hydrogen can be appropriately performed, so that the controllability of the control unit can be prevented from deteriorating.

In FIG. 4, a first hydrogen circulation system including a fuel pressure regulating valve 11, an ejector pump 13, a flow path shutoff valve 19, etc., a fuel pressure regulating valve 110, an ejector pump 130
The flow characteristics may be the same as or different from those of the second hydrogen circulation system including the flow path cutoff valve 190 and the like.

When the flow characteristics are the same, first, the fuel pressure regulating valve 11 of the first hydrogen circulation system is gradually opened as shown by the solid line a in FIG. At this point, as shown by the solid line b, the fuel pressure regulating valve 110 of the second hydrogen circulation system is gradually opened. Thereby, the fuel cell 1
It is possible to respond from a low flow rate to a high flow rate in accordance with the amount of power generation.

On the other hand, when the flow rate characteristics are different, as shown in FIG. 6, the fuel pressure regulating valve 11 of the first hydrogen circulation system is gradually opened, and the flow rate over the required flow rate at this time is reduced. The shortage is detected from the power generation amount of the fuel cell 1 and the like, and based on this, the opening degree of the fuel pressure regulating valve 110 is adjusted in such a manner that the second hydrogen circulation system corrects the flow rate.

When the flow characteristics are different, the hydrogen supply capacity of the second hydrogen circulation system is set lower than that of the first hydrogen circulation system, and each pipe has a smaller capacity of the second hydrogen circulation system.
Set the piping diameter of the hydrogen circulation system to small. That is, in FIG. 4, regarding the pipe diameter, the pipe 53 is smaller than the pipe 43, the pipe 57 is smaller than the pipe 21, and the pipe 59 is smaller than the pipe 49, respectively.

As described above, when the pipe diameters are different between the first and second hydrogen circulating systems, both the merging section 51 and the branching section 55 are shown in FIGS. 7 (a) and 7 (b). As shown in the figure, the inclination angle θ ₁ of the small-diameter straight pipes 53, 57 with respect to the horizontal plane H is changed to the straight large-diameter pipe 4.
It is larger than the inclination angle theta ₂ of 3, 21, and more vertical close state. For example, the inclination angle theta ₂ of the large-diameter pipe 43,21 is set to be 50 degrees the fuel cell system as the preferred angle of inclination when installed in a vehicle, a small diameter pipe 5
The inclination angle θ _{1 of} 3,57 is an angle exceeding 50 degrees.

The inclination angle θ of the small-diameter pipes 53 and 57
_1, and greater than the inclination angle theta ₂ of the pipe 43,21 of larger diameter, by a more vertical close state, the retention of condensed water in the condensed water within the small diameter pipes 53 and 57 easily stay Thus, the supply of hydrogen to the fuel cell 1 can be appropriately performed.

FIGS. 8 (a) and 8 (b) show respective pipes 43 and 53.
In this case, the radius of curvature R ₁ of the small-diameter pipes 53 and 57 is smaller than the radius of curvature R ₂ of the large-diameter pipes 43 and 21. . As a result, the small-diameter pipes 43 and 21 are closer to the vertical than the large-diameter pipes 43 and 21,
It is possible to prevent the condensed water from staying in the small-diameter pipes 53 and 57 where the condensed water easily stays.

[0067] Incidentally, the R ₁ = pipe diameter side as R ₂ 53, 57 without the R ₁ <R _2, for pipes 43,21 of the large diameter side, if the more vertical close state, R ₁ = R ₂ may be used.

In short, the pipes 53 and 57 on the small diameter side where the condensed water is liable to stay are made closer to vertical,
The water in the small-diameter pipes 53 and 57 is changed to the large-diameter pipes 43 and 2.
1, the water can efficiently flow down, and water can be prevented from staying in the small-diameter pipes 53, 57.

FIG. 9 shows a configuration in which a throttle 61 is provided on the pipe 21 side of the junction 55 in FIG. 7B. By providing the throttle 61, the gas flow velocity in the throttle 61 increases, so that the condensed water generated in the small-diameter pipe 57 flows down to the large-diameter pipe 21 so as to be sucked into this high-speed gas flow. ,
The stagnation of water in the pipe 57 can be prevented.

Note that. The same effect can be obtained by providing a stop in the branch 51 shown in FIG. 7A and also in the junction 51 and the branch 55 shown in FIGS. 8A and 8B in the same manner as the stop 61 described above. can get.

FIG. 10 is a sectional view of the ejector pumps 13 and 130. FIG. 3A shows the exhaust fuel inlets 13b, 1b.
The flow of gas in the suction port SP having the fuel mixture 30b is supplied from the raw fuel inlets 13c and 130c to the mixed fuel outlet 13
a, 130a in a direction perpendicular to the gas flow downward in the vertical direction.

The raw fuel inlets 13c, 13 in FIG.
0c is a position higher than the mixed fuel outlets 13a, 130a, and the raw fuel inlets 13c, 130c and the mixed fuel outlet 13
a, the angle α between the horizontal line H connecting the straight line P connecting
Is a right angle. Thereby, the ejectors 13, 13
The stagnation of condensed water within 0 can be prevented. In addition,
The angle α between the straight line P and the horizontal plane H is determined in consideration of the inclination and acceleration of the vehicle when the fuel cell device is mounted on the vehicle,
The range may be 50 degrees to 90 degrees.

FIG. 10B is different from FIG. 10A in that the suction port SP is connected to the exhaust fuel inlets 13b and 130b.
However, the exhaust fuel inlets 13b, 130b and the ejector 1
Ejector junction 65 with fuel passage 63 in
It is formed to be inclined to a higher position.
By doing so, it is possible to reliably prevent the condensed water from staying in the ejectors 13 and 130 including the inside of the suction port SP. In FIG. 10B, the angle β formed between the center line Q of the flow in the suction port SP and the straight line P takes into consideration the inclination of the vehicle when the fuel cell device is mounted on the vehicle, acceleration, and the like. It is desirable that the angle be about 50 degrees.

In each of the embodiments described above,
Although the ejector pumps 13 and 130 are used as the fuel circulating means, the invention is not limited to this as long as hydrogen is circulated.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a fuel cell device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the upper and lower positional relationships of respective components of a hydrogen circulation system in the fuel cell device of FIG.

FIG. 3 is an overall configuration diagram of a fuel cell device according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing the upper and lower positional relationship of each component of a hydrogen circulation system in the fuel cell device of FIG. 3;

FIG. 5 is an opening characteristic diagram of each fuel pressure regulating valve with respect to a required flow rate when two hydrogen circulation systems have the same flow rate characteristic.

FIG. 6 is an opening characteristic diagram of a fuel pressure regulating valve on a main side with respect to a required flow rate when two hydrogen circulation systems have different flow rate characteristics.

FIG. 7A is an explanatory diagram of an operation of a merging portion when a pipe is linear, and FIG. 7B is an explanatory diagram of an operation of a branch portion when a pipe is linear.

8A is an explanatory diagram of an operation of a merging portion when the pipe is curved, and FIG. 8B is an explanatory diagram of an operation of a branch portion when the pipe is curved.

FIG. 9 is an operation explanatory diagram showing an example in which a stop is provided in the branch portion shown in FIG. 7B.

FIGS. 10A and 10B are cross-sectional views of the ejector pump, wherein FIG. 10A shows a state in which a suction port is arranged orthogonal to a fuel passage in the ejector pump, and FIG. 10B shows a state in which the suction port is inclined with respect to the fuel passage in the ejector pump. It is arranged as follows.

[Explanation of symbols]

 Reference Signs List 1 fuel cell 3 fuel electrode 3a fuel inlet 3b fuel outlet 7 humidifier 13,130 ejector pump (fuel circulating means) 13a, 130a mixed fuel outlet 13b, 130b discharged fuel inlet 13c, 130c raw fuel inlet 15 supply side water separator ( Fuel supply side water separation means) 15a mixed fuel inlet 17 discharge side water separator (fuel discharge side water separation means) 19,190 flow path cutoff valve 21,57 parallel pipe 23 purge branch section 25 purge pipe 27 purge gas cutoff valve 43, 53 Parallel piping 51 Merging part 55 Branch part 61 Restrictor 63 Fuel passage 65 Merging part in ejector

Claims (12)

[Claims] 1. A fuel cell device comprising a fuel circulation means for mixing raw fuel and fuel discharged from a fuel outlet of a fuel electrode in a fuel cell and circulating the mixed fuel to a fuel inlet of the fuel electrode. A flow path cutoff valve is provided in a pipe between a fuel outlet of the fuel electrode and a discharge fuel inlet of the fuel circulation means, and the flow path cutoff valve is disposed at a position higher than the discharge fuel inlet of the fuel circulation means. A fuel cell device comprising: 2. The fuel cell device according to claim 1, wherein the fuel supplied to the fuel cell is humidified. 3. A fuel discharge side water separating means for separating water in discharged fuel is provided in a pipe between a fuel outlet of a fuel electrode and a flow path cutoff valve, and the fuel discharge side water separating means is provided with the fuel outlet and the fuel outlet. 3. The fuel cell device according to claim 1, wherein the fuel cell device is arranged at a position lower than the flow path shutoff valve. 4. A purge pipe for discharging discharged fuel to the outside is connected to a pipe on the upstream side of the flow path cutoff valve to provide a purge branch portion, and a purge gas cutoff valve is provided in the purge pipe. 4. The fuel cell device according to claim 1, wherein the fuel cell device is disposed at a position higher than the purge branch portion. 5. A fuel supply-side water separation means is provided in a pipe connected to a mixed fuel outlet of the fuel circulation means, and a mixed fuel inlet of the fuel supply-side water separation means is connected to a mixed fuel outlet of the fuel circulation means. The fuel cell device according to any one of claims 1 to 4, wherein the fuel cell device is arranged at a low position. 6. A plurality of pipes connected to a fuel inlet of a fuel cell are provided in parallel, a fuel circulation means is arranged in each parallel pipe, and a plurality of pipes connected to a fuel outlet of the fuel cell are provided in parallel. The fuel cell device according to any one of claims 1 to 5, wherein a flow path cutoff valve is provided in each of the parallel pipes. 7. The fuel circulation means according to claim 6, wherein the circulation flow characteristics are different from each other, and accordingly, the diameter of each parallel pipe connected to each fuel circulation means is also different.
The fuel cell device according to claim 1. 8. A small junction between at least one of a junction of a plurality of parallel pipes connected to a fuel inlet of a fuel cell and a branch of a parallel pipe connected to a fuel outlet of the fuel cell. 8. The fuel cell device according to claim 7, wherein the small-diameter pipe on the flow rate side is arranged to be closer to the vertical than the large-diameter pipe on the large flow rate side. 9. An inclination angle of a small-diameter straight pipe on a small flow rate side with respect to a horizontal plane is larger than an inclination angle of a large-diameter straight pipe on a large flow rate side. The fuel cell device according to claim 1. 10. The fuel according to claim 8, wherein the radius of curvature of the curved pipe having a small diameter on the small flow rate side is smaller than the radius of curvature of the curved pipe having a large diameter on the large flow rate side. Battery device. 11. The fuel cell according to claim 7, wherein a throttle is provided in at least one of the large-diameter pipes at a junction or a branch of the parallel pipes. apparatus. 12. The fuel supply device according to claim 1, wherein a raw fuel inlet of the fuel circulating means is disposed at a position higher than the mixed fuel outlet, and a discharged fuel inlet of the fuel circulating means is connected to the discharged fuel inlet and a fuel passage in the fuel circulating means. The fuel cell device according to claim 1, wherein the fuel cell device is disposed at a position higher than the portion.