JP2009283185A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system for restraining decrease of insulation resistance of a piping, without lengthening parts extended upward and downward of the piping for product water of a fuel cell to flow in. <P>SOLUTION: The fuel cell system includes the fuel cell, the piping 15 through which product water 30 produced by power generation of the fuel cell flows, and a blocking part 20 fitted at a vertically extended piping part 15a extended upward and downward from the piping 15 separating at least part of the product water 30 from an inner periphery face 15c of the vertically extended piping part 15a. The blocking part 20 includes a platy base part 21, and a plurality of vertical plate parts 22 fitted to a top face of the base part 21 and arrayed in parallel in a direction crossing a flowing direction of the product water 30. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell system.

  In the fuel cell system, water (generated water) is generated by the power generation of the fuel cell. It is known that the conductivity of produced water increases when impurity ions (for example, metal ions) are mixed with the produced water. When the conductivity in the generated water increases, a path for current to flow is formed between the fuel cell system and a mobile body (for example, a vehicle) on which the fuel cell system is mounted, and the insulation resistance between the fuel cell and the mobile body is reduced. May decrease.

Conventionally, in order to avoid the above-described problem, a technique is known in which a blocking portion for blocking the flow of generated water is provided in a plurality of stages in a vertically extending portion of a pipe for discharging the generated water of a fuel cell. (For example, refer to Patent Document 1).
JP 2006-339078 A JP 2006-290033 A

  However, in the technique described in Patent Document 1 of the related art, since the obstructing portion is provided in a plurality of stages in the vertically extending portion of the piping for discharging the generated water, it is necessary to lengthen the vertically extending portion of the piping. For this reason, when the length of the part extending up and down of the pipe cannot be made so long, for example, when the fuel cell is installed under the floor of the vehicle, it is difficult to apply the technique of Patent Document 1.

  This invention is made in view of such a problem, and can suppress the fall of the insulation resistance in piping, without lengthening the length of the up-and-down extending piping part extended up and down of the piping which discharges the produced water of a fuel cell. The object is to provide a fuel cell system.

The present invention employs the following means in order to solve the above problems.
That is, the present invention
A fuel cell;
Piping through which generated water generated by power generation of the fuel cell flows;
Provided in a vertically extending pipe part extending vertically in the pipe, and comprising an inhibiting part for separating at least a part of the generated water from an inner peripheral surface of the pipe,
The inhibition part has a plurality of protrusions or grooves arranged in a direction intersecting the direction in which the generated water flows.

  According to the present invention, at least a part of the generated water generated by the power generation of the fuel cell is separated from the inner peripheral surface of the pipe by the hindering portion, and the amount of generated water that contacts the inner peripheral surface of the pipe is reduced. Since the generated water is divided into a plurality of portions by the plurality of protrusions or grooves, a break can be formed in the generated water, and a decrease in insulation resistance in the piping can be suppressed. In addition, since the inhibition portion can be effectively suppressed from lowering the insulation resistance in the piping by providing, for example, only one stage in the vertically extending piping portion extending up and down of the piping, it is not necessary to increase the length of the vertically extending piping portion of the piping. . Therefore, the fuel cell system can be installed under the floor of the vehicle.

Here, the said inhibition part can be made into the structure provided in the said up-and-down extending piping part of the said piping over several steps. According to this configuration, since at least a part of the generated water can be separated from the inner peripheral surface of the pipe over a plurality of stages and a break can be formed in the generated water, a decrease in insulation resistance in the pipe can be suppressed more effectively.

  Moreover, it can be set as the structure where the said protrusion or the said groove | channel of the said inhibition part adjacent up and down is mutually arrange | positioned. Furthermore, it can be set as the structure which the said processus | protrusion or the groove | channel which adjoins up and down is arranged alternately. According to this configuration, the generated water can be more reliably separated from the inner peripheral surface of the pipe.

  According to the present invention, at least a part of the generated water generated by the power generation of the fuel cell is separated from the inner peripheral surface of the pipe by the hindrance in the pipe, and the generated water can be divided into a plurality of parts. It can suppress that insulation resistance falls. Moreover, since the fall of the insulation resistance in piping can be suppressed by providing only one step of obstruction | occlusion parts in piping, it is not necessary to lengthen the length of piping. Therefore, the fuel cell system can be installed in a place where the vertical distance is relatively narrow, such as under the floor of a vehicle.

  Hereinafter, a fuel cell system according to the best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described with reference to the drawings. In addition, the structure of the following embodiment is an illustration and this invention is not limited to the structure of embodiment.

<< First Embodiment >>
FIG. 1 shows a configuration of a fuel cell system 10 according to a first embodiment of the present invention. The fuel cell system 10 is mounted on a moving body such as a vehicle. In FIG. 1, a polymer electrolyte fuel cell (PEFC) is applied to the fuel cell 1. The fuel cell 1 is composed of at least one cell.

This cell includes a solid polymer electrolyte membrane, a fuel electrode (anode) and an air electrode (oxidant electrode: cathode) that sandwich the solid polymer electrolyte membrane from both sides, and a fuel electrode side separator that sandwiches these fuel electrode and air electrode. And an air electrode side separator.

The fuel electrode has a diffusion layer and a catalyst layer. A fuel containing hydrogen such as hydrogen gas or hydrogen rich gas is supplied to the fuel electrode by the fuel supply system. The fuel supplied to the fuel electrode is diffused in the diffusion layer and reaches the catalyst layer. In the catalyst layer, hydrogen is separated into protons (hydrogen ions) and electrons. Hydrogen ions move to the air electrode through the solid polymer electrolyte membrane, and electrons move to the air electrode through an external circuit (not shown).

  On the other hand, the air electrode has a diffusion layer and a catalyst layer. An oxidant gas such as air is supplied to the air electrode by the oxidant supply system. The oxidant gas supplied to the air electrode is diffused in the diffusion layer and reaches the catalyst layer. In the catalyst layer, water is generated through a reaction between the oxidant gas, hydrogen ions that have reached the air electrode through the solid polymer electrolyte membrane, and electrons that have reached the air electrode through the external circuit.

  Electrons passing through an external circuit during a reaction at the fuel electrode and the air electrode are used as electric power for a load connected between both terminals of the fuel cell 1. The fuel cell 1 is connected to a fuel supply / discharge system for supplying and discharging fuel and an oxidant supply / discharge system for supplying and discharging oxidant. In FIG. 1, the fuel supply / discharge system is configured as follows.

In other words, the fuel inlet 1 </ b> A provided in the fuel cell 1 is connected to the hydrogen source (for example, a tank storing high-pressure hydrogen) 2 and the pressure regulating valve 3 through the pipe 4. On the other hand, a fuel outlet 1 B provided in the fuel cell 1 is connected to an inlet of a gas-liquid separator 6 for fuel gas via a pipe 5. Inside the fuel cell 1, there is provided a fuel passage 1C connecting the fuel inlet 1A and the fuel outlet 1B and passing through the fuel electrode of the cell.

  The gas side outlet of the gas-liquid separator 6 is connected to an inlet of a circulation pump 8 driven by a motor via a pipe 7. A pipe 9 is provided at the outlet of the circulation pump 8. The pipe 9 is connected to the pipe 4 via the check valve 31. Further, an exhaust pipe 11 and an exhaust valve 12 are arranged in the pipe 9. The gas discharged from the exhaust valve 12 passes through a diluter (not shown), and after being diluted with hydrogen, is discharged to the outside.

  With such a configuration, high-pressure hydrogen gas (fuel gas) delivered from the hydrogen source 2 is regulated by the pressure regulating valve 3 and then supplied to the fuel cell 1 from the fuel inlet 1 </ b> A through the pipe 4. Hydrogen gas is consumed in the electrode reaction at the fuel electrode when passing through the fuel passage 1C. Thereafter, the hydrogen gas that has passed through the fuel electrode is discharged from the fuel outlet 1 </ b> B to the pipe 5 (outside of the fuel cell 1) as a fuel off-gas and sent to the gas-liquid separator 6.

  In the gas-liquid separator 6, the fuel off-gas is separated into a gas phase component and a liquid phase component. The gas phase component is supplied to the pipe 4 again by the circulation pump 8 through the pipe 7. Thereby, the fuel gas supplied to the fuel cell 1 is configured to circulate. Then, hydrogen in the fuel off-gas that has not been consumed at the fuel electrode (supplied excessively) is supplied to the fuel electrode again. Further, the hydrogen concentration of the fuel gas is maintained in an appropriate range by opening / closing control of the pressure regulating valve 3 and the exhaust valve 12.

  On the other hand, in FIG. 1, the oxidant supply / discharge system is configured as follows. In other words, the oxidant inlet 1 </ b> D provided in the fuel cell 1 is connected to the air compressor 14 via the pipe 13. An oxidant outlet 1 </ b> E provided in the fuel cell 1 is connected to an inlet of an exhaust pipe (muffler) 16 through a pipe 15. Inside the fuel cell 1, there is provided an oxidant passage 1F that connects the oxidant inlet 1D and the oxidant outlet 1E and that passes through the air electrode of the cell. Furthermore, the outlet of the liquid phase component of the gas-liquid separator 6 is connected to one end of the pipe 17 via a drain valve 18. The other end of the pipe 17 is connected to the exhaust pipe 16.

  In the fuel cell system 10, air as an oxidant gas is supplied to the fuel cell 1 through a pipe 13 by driving the air compressor 14 with a motor. Air enters the fuel cell 1 from the oxidant inlet 1D and is consumed in the electrode reaction at the air electrode when passing through the oxidant passage 1F. Thereafter, the air that has passed through the air electrode is discharged as an oxidant off-gas from the oxidant outlet 1E to the pipe 15 (outside the fuel cell 1). The oxidant off-gas sent to the pipe 15 is introduced into the exhaust pipe 16 and discharged outside (in the atmosphere).

Here, part of the water (generated water) generated at the air electrode by the power generation of the fuel cell 1 moves to the fuel electrode through the solid polymer electrolyte membrane, and is discharged to the pipe 5 together with the fuel off-gas. Thereafter, the produced water reaches the exhaust pipe 16 through the pipe 5, the gas-liquid separator 6, the drain valve 18, and the pipe 17, and is discharged from the exhaust pipe 16. A part of the produced water 30 generated at the air electrode is discharged together with the oxidant off-gas to the pipe 15, reaches the exhaust pipe 16, and is discharged. The pipe 5, the gas-liquid separator 6, the drain valve 18, the pipe 17, the pipe 15, and the exhaust pipe 16 constitute a drainage passage (pipe) for the generated water 30.

For example, impurity ions (for example, metal ions) eluted from the fuel cell 1 may be eluted in the generated water 30. When impurity ions are mixed into the generated water 30, the conductivity increases. When the product water containing impurity ions is connected in the pipe, a current flow path is formed there, and the insulation resistance between the pipe and the moving body (vehicle) component may be reduced.

  Here, when the fuel cell 1 is installed in the lower part of the vehicle, for example, under the floor of the vehicle, the fuel outlet 1B or the oxidant outlet 1E that is the outlet of the generated water 30 of the fuel cell 1 and the outlet of the pipe 5 or the pipe 15 19 and the height of the same, the generated water 30 discharged into the pipe 5 or 15 is not interrupted, and the insulation resistance of the pipe 5 or 15 may be reduced.

  Therefore, as shown in FIG. 2, the fuel cell system 10 of the present invention extends above and below a pipe connected to the oxidant outlet 1E or the fuel outlet 1B, in this embodiment, a pipe 15 connected to the oxidant outlet 1E. By providing the obstruction part 20 in the vertically extending piping part 15a which is a part, at least a part of the generated water 30 flowing through the vertically extending piping part 15a of the pipe 15 is separated (floated) from the inner peripheral surface 15c of the vertically extending piping part 15a. ) Is configured as follows.

  Thereby, it is possible to suppress a decrease in the insulation resistance of the pipe 15 without lengthening the vertically extending pipe section 15a. In FIG. 2, components other than the pipe 15 connected to the fuel cell 1 and the oxidant outlet 1E are omitted. In the present embodiment, the case where the inhibition unit 20 is provided in the pipe 15 connected to the oxidant outlet 1E of the fuel cell 1 will be described. However, the inhibition unit 20 is connected to the fuel outlet 1B of the fuel cell 1. Applicable to piping 5 and the like.

  Although this embodiment demonstrates the case where the inhibition part 20 is provided in the up-and-down extending piping part 15a of the piping 15 which discharges the produced water 30 produced | generated by the air electrode side in the fuel cell 1, the inhibition part 20 is a fuel cell. It can be provided in a vertically extending piping portion of a pipe through which the generated water 30 flows, such as a vertically extending piping portion in the piping 5 that discharges the generated water 30 generated on one fuel electrode side.

  The vertically extending pipe portion 15a of the pipe 15 is formed in a cylindrical shape. In the present embodiment, the vertically extending pipe portion 15a extends in a substantially vertical direction, but the vertically extending pipe portion 15a may have a certain inclination with respect to the vertical direction as long as the generated water 30 flows up and down. good.

  In addition, here, the inhibition portion 20 is formed of metal, but may be formed of various materials such as resin. Moreover, when forming the inhibition part 20 with a metal, it is preferable to contain an insulating agent in the metal used as a raw material. That is, it is preferable to form the inhibition part 20 with an insulating material. Furthermore, since the produced water 30 discharged from the fuel cell 1 is relatively small, the produced water 30 flows in contact with a part of the inner peripheral surface of the vertically extending pipe portion 15a in the pipe 15. For this reason, it is preferable to arrange | position the inhibiting part 20 in the part which the production | generation water 30 contacts among the up-and-down extending piping parts 15a.

  For example, as shown in FIG. 2, when the pipe 15 has a horizontal extension pipe part 15 b extending from the fuel cell 1 in the horizontal direction and a vertical extension pipe part 15 a extending downward from the horizontal extension pipe part 15 b, As shown in FIG. 3, the produced water 30 flows in contact with or close to the portion on the fuel cell 1 side (the left portion of the vertically extending piping portion 15a in FIG. 3) on the inner peripheral surface 15c of the vertically extending piping portion 15a. Therefore, in the present embodiment, the inhibition portion 20 is provided on the fuel cell 1 side of the inner peripheral surface 15c of the vertically extending piping portion 15a.

  As shown in FIG. 4, the blocking portion 20 includes a base portion 21 fixed to the inner peripheral surface 15c of the vertically extending piping portion 15a, and a plurality of protrusions or grooves provided on the upper surface of the base portion 21. It has the vertical board part 22 which is a protrusion in a form. The base portion 21 has a shape in which a part on the outer peripheral side of a disk having the same diameter as the inner periphery 15c of the pipe 15 is cut out by a linear edge 21a.

The vertical plate portion 22 extends from the linear end edge 21a of the base portion 21 in a direction substantially orthogonal to the end edge 21a. As shown in FIG. 5, a predetermined gap is provided between the inner edge 22a of the vertical plate portion 22 and the inner peripheral surface 15c of the vertically extending piping portion 15a. Moreover, the some vertical board part 22 is mutually arrange | positioned in parallel. Furthermore, the vertical plate portion 22 is arranged in parallel in a direction intersecting with the direction (vertical direction) in which the generated water 30 flows, in the present embodiment, in a substantially orthogonal direction.

  The base portion 21 and the vertical plate portion 22 of the inhibition portion 20 can be integrally formed by cutting a metal member. Moreover, the inhibition part 20 can be attached by fixing the base part 21 to a predetermined position on the inner peripheral surface 15c of the vertically extending pipe part 15a with an adhesive or the like.

  In the inhibition unit 20, the generated water 30 that has fallen in contact with or close to the inner peripheral surface 15 c of the vertically extending piping part 15 a falls on the base part 21 of the inhibiting part 20 and moves up and down on the base part 21. It flows in a direction away from the inner peripheral surface 15c of the portion 15a, is divided into a plurality by the plurality of vertical plate portions 22, and falls from the linear edge 21a of the base portion 21.

  According to the fuel cell system 10, the obstruction part 20 having the base part 21 and the plurality of vertical plate parts 22 arranged in parallel on the base part 21 is provided in the vertically extending pipe part 15 a of the pipe 15. Since the plurality of vertical plate portions 22 are arranged in parallel in a direction intersecting with the flowing direction of the generated water 30 in the vertically extending piping portion 15a of the pipe 15, the generated water is generated by the plurality of vertical plate portions 22. 30 is divided into a plurality of parts, and at least a part of the divided plurality of generated waters 30 is separated from the inner peripheral surface 15c of the vertically extending pipe portion 15a. Thereby, a break can be formed in the produced water 30. Accordingly, the amount of the produced water 30 that contacts the inner peripheral surface 15c of the vertically extending pipe portion 15a is reduced, and the produced water 30 itself is interrupted, so that it is possible to suppress the insulation resistance of the pipe 15 from being lowered.

  Moreover, since the inhibition part 20 can suppress the fall of the insulation resistance in the piping 15 by providing only one step in the up-and-down extending piping part 15a of the piping 15, it is not necessary to lengthen the up-and-down extending piping part 15a. Therefore, the fuel cell system 10 can be installed in a place where the vertical distance is relatively narrow, such as under the floor of a vehicle.

  In addition, the space | interval b (refer FIG. 4) of the vertical plate parts 22 and the length L of the vertical plate part 22 are the internal diameter of the up-and-down extending piping part 15a in the piping 15, and the flow volume of the produced water 30 which flows through the up-and-down extending piping part 15a. It can set suitably according to etc.

  Moreover, in the said embodiment, although the base part 21 and the vertical board part 22 of the inhibition part 20 were formed integrally, the base part 21 and the vertical board part 22 are formed separately, and a plurality of pieces are formed on the base part 21. The vertical plate portion 22 can be integrally joined by appropriate joining means such as welding, fitting, and adhesion. Further, the base portion 21 can be provided with a groove in place of the protrusions such as the vertical plate portion 22, whereby the same effect as described above can be obtained. In this case, it is preferable that the thickness of the base portion 21 is made relatively thick and the depth of the groove is increased to some extent.

<< Second Embodiment >>
Although 1st Embodiment demonstrated the case where the obstructing part 20 was provided in the up-and-down extending piping part 15a of the piping 15 only one step, as shown in FIG. It can be provided over the steps (two or more steps). In this case, the vertical plate portion 22 in the upper inhibition portion 20 and the vertical plate portion 22 in the lower inhibition portion 20 can be provided so as to overlap in the vertical direction.

Moreover, as shown in FIG. 6, it can arrange | position so that the up-and-down vertical board part 22 may become alternate. In this case, since the generated water 30 divided by the upper vertical plate portion 22 is further divided by the lower vertical plate portion 22, it is possible to further suppress a decrease in insulation resistance in the pipe 15.

<< Third Embodiment >>
The obstruction part 20 of 1st and 2nd embodiment provides the vertical board part 22 on the base part 21, and the produced | generated water 30 flows on the base part 21 in a horizontal direction, and is divided | segmented by the several vertical board part 22. FIG. However, as will be described next, when the generated water 30 falls in the vertical direction, it can be divided into a plurality of parts.

  FIG. 8 shows the inhibition unit 40 of the third embodiment. The inhibition portion 40 includes a partial circular base portion 41 and a plurality of vertical plate portions 42 protruding from the linear end edge 41 a of the base portion 41. As shown in FIG. 9, the base portion 41 has an arcuate edge 41b having the same radius of curvature as the radius of the inner peripheral surface 15c of the vertically extending pipe portion 15a. The vertical plate portions 42 are arranged in parallel to each other. Further, the vertical plate portion 42 is arranged in parallel in a direction intersecting with the direction in which the generated water 30 flows (in the present embodiment, a direction substantially orthogonal).

  The base portion 41 and the vertical plate portion 42 of the inhibition portion 40 can be integrally formed by cutting a metal member. Moreover, the inhibiting part 40 can be fixed with an adhesive or the like at a predetermined position on the inner peripheral surface 15c of the vertically extending pipe part 15a.

  According to the inhibition unit 40, the generated water 30 that falls vertically by the plurality of vertical plate portions 42 is divided into a plurality of parts, and at least a part of the divided generated water 30, in this embodiment, substantially all are vertically stretched piping parts. The generated water 30 is separated from the inner peripheral surface 15c of 15a. Therefore, it can suppress that the insulation resistance of the piping 15 falls.

  In the above embodiment, the base portion 41 and the vertical plate portion 42 are integrally formed. However, as shown in FIG. 10, the base portion 41 and the vertical plate portion 42 are separately formed, and the vertical plate portion is formed. 42 can be coupled to the base portion 41 by an appropriate joining means such as welding, fitting, or bonding.

1 is a block diagram showing a fuel cell system according to a first embodiment. It is a figure which shows the state which provided the obstruction part which concerns on 1st Embodiment in the up-and-down extending | stretching piping part of piping. It is a longitudinal cross-sectional view which shows the inhibition part which concerns on 1st Embodiment. It is a perspective view which shows the inhibition part which concerns on 1st Embodiment. It is a top view which shows the inhibition part which concerns on 1st Embodiment, and is A arrow line view of FIG. It is sectional drawing at the time of providing the obstruction part which concerns on 2nd Embodiment in multiple steps. It is a top view which shows the case where the up-and-down vertical board part which concerns on 2nd Embodiment is arrange | positioned alternately, and is B arrow line view of FIG. It is sectional drawing which shows the inhibition part which concerns on 3rd Embodiment. It is a top view which shows the inhibition part which concerns on 3rd Embodiment, and is C arrow line view of FIG. It is a top view which shows the case where the base part and vertical board part of the inhibition part which concern on 3rd Embodiment are formed separately.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell 1A Fuel inlet 1B Fuel outlet 1C Fuel passage 1D Oxidant inlet 1E Oxidant outlet 1F Oxidant passage 2 Hydrogen source 3 Pressure regulating valve 15 Piping 6 Gas-liquid separator 8 Circulation pump 10 Fuel cell system 11 Exhaust pipe 12 Exhaust valve Reference Signs List 14 Air Compressor 15a Vertical Stretched Piping Section 15b Horizontal Stretched Piping Section 15c Piping Inner Surface 16 Exhaust Pipe 18 Drain Valve 19 Outlet 20, 40 Blocking Section 21, 41 Base Portion 21a Linear Edge 21b Arc-shaped Edge 22 42 Vertical plate (projection)
22a Tip of vertical plate part 30 Generated water 31 Check valve 41a Linear edge 41b Arc-shaped edge

Claims (3)

A fuel cell;
Piping through which generated water generated by power generation of the fuel cell flows;
Provided in a vertically extending pipe part extending vertically in the pipe, and comprising an inhibiting part for separating at least a part of the generated water from an inner peripheral surface of the pipe,
The said inhibition part is a fuel cell system which has a some protrusion or groove | channel arranged in the direction which cross | intersects with respect to the direction through which the said generated water flows.   The fuel cell system according to claim 1, wherein the inhibition part is provided in a plurality of stages in the vertical direction.   The fuel cell system according to claim 2, wherein the protrusions or the grooves of the obstructing portions adjacent to each other in the vertical direction are arranged in directions opposite to each other.

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