JPH0521082A - Manifold for reaction gas of phosphoric acid fuel cell - Google Patents

Abstract

PURPOSE:To provide a coating layer of the thickness of a minimum necessary level by installing a bush, which has anti-corrosion and insulating characteristics, and which is provided with a flange and a channel hole, in a nozzle at intervals between the flange and the coating layer provided on the side route of a manifold, and by mounting this on the manifold. CONSTITUTION:A bush 5 having anti-corrosion and insulating characteristics is composed of a screw-processed installation part 6, a mounting part 8, and of a flange 9 protruded away from a mounting seat 7 of the mounting part 8. A channel hole 10 is opened to the end surfaces of the mounting part 8 and the installation part 6. The bush 5 is mounted on a discharging manifold 1 in such a way that the installation part 6 is screwed into a nozzle 3 and the mounting seat 7 is connected to a coating layer 4 of a manifold side plate 2, which is fastened. A gap 11 is created between the coating layer 4 and the flange 9 thereby. A reaction gas is collected into the side plate 2, and is run down into the nozzle 3 as indicated by arrows in the drawing. The reaction gas thus being discharged is not flowed into the gap 11, while a phosphoric acid mist and the like is not adhered to the vicinity of the angle of mounting the nozzle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manifold attached to the side surface of a cell stack of a phosphoric acid fuel cell for supplying and discharging a reaction gas, and more particularly to a structure of a manifold for discharging the reaction gas.

[0002]

2. Description of the Related Art In a phosphoric acid fuel cell having a cell stack formed by stacking cells using phosphoric acid as an electrolyte, a cell stack of a cell stack for supplying and discharging a reaction gas to and from each cell of the cell stack. A manifold is attached to the side.

The manifold distributes the reaction gas to each cell of the cell stack when supplying the reaction gas to the cell stack, while discharging the reaction gas from each cell of the cell stack when the reaction gas is discharged.
It is composed of a manifold side plate that forms a chamber that collects the reaction gas discharged from each unit cell of the battery stack, and a nozzle that is attached to this side plate and through which the reaction gas flows.

By the way, an exhaust manifold shown in FIG. 3 is known as an exhaust manifold used when exhausting a reaction gas from a battery stack. In FIG. 3, the discharge manifold 1 is composed of a manifold side plate 2 and a nozzle 3, and the inner surface of the manifold side plate 2 and the nozzle 3 has a phosphoric acid mist and unit cells contained in the reaction gas discharged from the battery stack. The coating layer 4 is provided with a coating or sheet of polytetrafluoroethylene resin or the like in order to prevent insulation deterioration and corrosion due to phosphoric acid dripping from the like.

[0005]

In the above exhaust manifold, the phosphoric acid mist contained in the exhausted reaction gas changes the speed and direction of the exhausted reaction gas more rapidly than the flat portion. Many adhere to the vicinity.

However, since the coating of the coating layer 4 and the defects of the sheet are few in the flat portion and often occur in the vicinity of the nozzle mounting corner portion which is not the flat portion, in order to prevent this defect, the inner surface of the conventional discharge manifold 1 is coated. Although the coating layer 4 is provided by increasing the thickness of the layer, this method results in a coating layer having an unnecessarily large thickness on the inner surface portion of the manifold other than the vicinity of the nozzle mounting corner, resulting in high manufacturing cost. There is a drawback that

An object of the present invention is to provide a reaction of a phosphoric acid fuel cell in which the corrosion resistance and the insulating property in the vicinity of the nozzle mounting corner are not deteriorated even if the thickness of the coating layer on the inner surface of the reaction gas manifold is made to be the minimum necessary thickness. A gas exhaust manifold is provided.

[0008]

In order to solve the above-mentioned problems, according to the present invention, the battery is attached to the side surface of a battery stack formed by stacking cells having a phosphoric acid electrolyte and discharged from the battery stack. A manifold for a reaction gas of a phosphoric acid fuel cell, comprising a manifold side plate forming a chamber for collecting a reaction gas and a nozzle attached to the side plate, and having a coating layer having corrosion resistance and insulation on the inner surface. Which has a flange at the end of the nozzle, has flow passage holes open at both end surfaces, and is mounted on the nozzle with a bush having corrosion resistance and insulation properties with a gap between the flange and the coating layer of the manifold side plate. And

[0009] The bush is mounted on the nozzle, is thicker in a step from the mounting portion, and is protruded from a mounting portion having this step surface as a mounting seat and a mounting portion separated from the mounting seat. It is composed of a flange, a mounting part and a flow path hole that opens to the end surface of the mounting part, and is configured to have corrosion resistance and insulating properties. It shall be attached to the nozzle and attached to the manifold.

Further, an annular groove surrounding the flow path hole is provided in the mounting seat of the bush, and the bush is mounted through a gasket having corrosion resistance and insulation which is inserted into the groove, and the mounting seat is covered with a coating layer of the manifold side plate. , And the mounting part is mounted on the nozzle and mounted on the manifold.

[0011]

Operation: When a bush having a flange at one end and having flow passage holes open at both end faces and having corrosion resistance and insulation properties is attached to the nozzle, the flange and manifold side plate have corrosion resistance and insulation properties. There is a gap between the layers. At this time, a mounting part that mounts the bush on the nozzle, a mounting part that makes a step from this mounting part and becomes thicker, and a mounting part that uses this step surface as a mounting seat, and a flange that protrudes from a location apart from the mounting seat, and the mounting part. And a flow path hole that opens at the end face of the mounting portion, and is configured to have corrosion resistance and insulation properties.This bush has a mounting seat of the mounting portion that is provided on the manifold side plate and has corrosion resistance and insulation properties. By attaching the mounting portion to the nozzle and mounting it on the manifold by contacting the layer, the flange projects from a position away from the mounting seat, so there is a gap between the flange and the coating layer of the manifold side plate. .

By the way, the reaction gas discharged from each unit cell of the battery stack is collected in the chamber formed by the manifold side plate and then discharged to the outside through the nozzle. At this time, the gap between the flange of the bush and the coating layer of the manifold side plate becomes a dead space, and the reaction gas does not flow in. Therefore, since the phosphoric acid mist or the like in the discharged reaction gas does not adhere, even if there is a defect in the coating layer near the nozzle mounting corner, the insulation and corrosion resistance do not deteriorate. Therefore, the coating layer provided on the inner surface of the manifold is required to have a minimum necessary thickness that does not cause defects in the flat portion.

When the nozzle is mounted on the lowermost part of the manifold side plate, a gasket having corrosion resistance and insulation is inserted into an annular groove provided on the bush seat, and the bush is mounted on the seat as described above. Is attached to the cover layer of the manifold side plate, and the mounting part is attached to the nozzle to attach it to the manifold, so that the phosphoric acid mist and water drain flow into the gap between the flange of the bottom bush and the cover layer of the manifold side plate. However, since it does not flow into the vicinity of the nozzle mounting corner due to the gasket, even if there is a defect in the coating layer near the nozzle mounting corner, the insulation and corrosion resistance do not deteriorate.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial cross-sectional view of a reaction gas discharge manifold of a phosphoric acid fuel cell according to an embodiment of the present invention. In FIG. 1 and FIG. 2 which will be described later, the same parts as those of the conventional example of FIG. 1 is different from the conventional example in that a female thread is formed on the nozzle 3, and a bush 5 is screwed onto the female thread to be attached to the discharge manifold 1.

The bush 5 has a threaded mounting portion 6
And a mounting portion 8 having a stepped surface that is thicker than the mounting portion 6 and has a step surface as a mounting seat 7, and a flange 9 protruding away from the mounting seat 7 of the mounting portion 8. A flow path hole 10 that opens to the end face of the mounting portion 6 is provided. In addition, the bush 5 is made of an insulating material having corrosion resistance, or an insulating coating is applied to another material so as to prevent corrosion.
Has insulation properties.

To attach such a bush 5 to the discharge manifold 1, the mounting portion 6 of the bush 5 is attached to the nozzle 3.
Then, the mounting seat 7 of the mounting portion 8 is brought into contact with the covering layer 4 of the manifold side plate 2 and tightened. By doing so, a gap 11 is formed between the coating layer 4 of the manifold side plate 2 and the flange 9.

With such a structure, the reaction gas discharged from each unit cell of the battery stack is collected in the manifold side plate 2 and flows in the direction of the arrow to the nozzle 3 through the flow passage hole 10 of the bush 5. , Is sent to the outside through a pipe (not shown) connected to this. In this case, the discharged reaction gas does not flow into the gap 11, so that the phosphoric acid mist or the like does not adhere to the vicinity of the nozzle mounting corner.

FIG. 2 is a partial cross-sectional view of a reaction gas exhaust manifold of a phosphoric acid fuel cell according to another embodiment of the present invention. In FIG. 2, the nozzle 3 is the manifold side plate 2
It is installed at the bottom of. In this case, an annular groove 12 is provided in the mounting seat 7 of the mounting portion 8 of the bush 5, and a gasket 13 having corrosion resistance and insulation is inserted into this groove 12.
Then, the bush 5 is attached to the coating layer 4 of the manifold side plate 2 so that the mounting seat 7 is in contact with the coating layer 4 via the gasket 13.
It is attached by screwing on.

With such a structure, the reaction gas discharged from the unit cell of the battery stack flows from the inside of the manifold side plate 2 through the flow passage hole 10 of the bush 5 as described above, but into the gap 11 as described above. Does not flow into the reaction gas containing phosphoric acid mist. However, since the nozzle 3 is located at the lowermost portion, the phosphate mist and the drain of water flow into the gap 11, but the gasket 13 prevents them from flowing near the nozzle mounting corners. Therefore, even if the nozzle 3 is located at the lowermost portion of the manifold side plate 2, phosphoric acid or the like does not adhere to the vicinity of the nozzle mounting corner.

[0020]

As is apparent from the above description, according to the present invention, a bush having a corrosion resistance and an insulating property and having a flange and a flow path hole is provided on the flange and the manifold side plate. By mounting the nozzle on the discharge manifold with a gap between the cover layer and the coating layer, the gap becomes a dead space, and the reaction gas discharged from the battery stack does not flow into the discharge manifold. The phosphoric acid mist mixed with the reaction gas does not adhere to the vicinity of the nozzle mounting corner, and therefore the corrosion resistance and insulating property can be maintained near the nozzle mounting corner even if there are defects in the coating layer. The thickness is required to be the minimum necessary thickness that does not cause defects in the flat portion of the manifold, which has the effect of reducing the manufacturing cost.

When the nozzle is attached to the lower part of the manifold side plate, a gasket having corrosion resistance and insulation is inserted in the annular groove provided in the bush, and the bush is contacted with the covering layer of the manifold side plate through the gasket. ,
Since the drain is attached to the discharge manifold with a gap as described above, even if the drainage of phosphoric acid or water flows into this gap, it is blocked by the gasket and does not flow near the nozzle mounting corners. Is obtained.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a reaction gas discharge manifold of a phosphoric acid fuel cell according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of a reaction gas exhaust manifold of a phosphoric acid fuel cell according to another embodiment of the present invention.

FIG. 3 is a partial sectional view of a conventional reaction gas discharge manifold of a phosphoric acid fuel cell.

[Explanation of symbols]

1 Discharge manifold 2 Manifold side plate 3 nozzles 4 coating layer 5 bush 6 mounting part 7 mounting seat 8 Mounting part 9 flange 10 channel holes 12 grooves 13 gasket

Claims (3)

[Claims] 1. A manifold side plate, which is attached to a side surface of a battery stack formed by stacking single cells having a phosphoric acid electrolyte and forms a chamber in which a reaction gas discharged from the battery stack is collected, and a side plate. In a reaction gas manifold of a phosphoric acid fuel cell, which comprises a nozzle to be attached and has a coating layer having corrosion resistance and insulation on the inner surface, a flange is provided at one end, and a flow passage hole that opens at both end surfaces is provided. Have,
A reaction gas manifold for a phosphoric acid fuel cell, characterized in that a bush having corrosion resistance and insulation is attached to the nozzle with a gap between the flange and the coating layer of the manifold side plate. 2. The reaction gas manifold for a phosphoric acid fuel cell according to claim 1, wherein the bush has a mounting portion that can be mounted on the nozzle, and the mounting portion is thicker in a stepped manner. A mounting portion that is a seat, a flange that projects from a portion of the mounting portion that is distant from the mounting seat, and a flow path hole that opens to the end surface of the mounting portion and the mounting portion, and is configured to have corrosion resistance and insulation properties, A reaction gas manifold for a phosphoric acid fuel cell, characterized in that the bush is attached to the manifold with its mounting seat in contact with the coating layer of the manifold side plate, and the mounting portion is mounted to the nozzle. 3. The reaction gas manifold for a phosphoric acid fuel cell according to claim 2, wherein an annular groove surrounding a flow path hole is provided in the mounting seat of the bush, and corrosion resistance and insulation are inserted into the groove. A reaction gas manifold for a phosphoric acid fuel cell, characterized in that the bush has a mounting seat in contact with a coating layer of a manifold side plate through a gasket, and the mounting portion is mounted on a nozzle to mount the bush on the manifold.