JP2001202983A - Gas manifold for phosphate fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas manifold of low manufacturing cost, of which the piping connecting section allows easy anticorrosive treatment. SOLUTION: A PTFE(polytetrafluoroethylene) ring 6A of a U-shape cross section for a corrosion protection sheet lining is mounted in the nozzle flange 3, attached to the gas manifold for piping connection. A cushion sheet 7 is interposed between the connection piping 8 provided with the lining 9 and the PTFE ring 6A and the nozzle flange 3 to be connected, and the connection piping 8 is tightened to the nozzle flange 3 by means of the tightening stud 10. The other side of the PTFE ring 6A is fused at the fusion section 5A with the corrosion protection sheet 4, attached inside the manifold side plate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas manifold mounted on a cell stack of a phosphoric acid type fuel cell, and more particularly to a connection structure of piping for supplying and discharging gas.

[0002]

2. Description of the Related Art Since a phosphoric acid type fuel cell is operated at a high temperature using liquid phosphoric acid as an electrolyte, the gas flowing through the cell stack contains phosphoric acid mist. Therefore, the inner surface of the gas manifold mounted on the battery stack is subjected to anticorrosion treatment using a sheet made of polytetrafluoroethylene (hereinafter abbreviated as PTFE), and the like.
Corrosion prevention measures against phosphoric acid mist are also taken at the gas supply / discharge pipe connection part connected to the gas manifold using a PTFE-wrapped gasket.

FIG. 4 is a cross-sectional view showing a basic configuration of a pipe connection portion of a conventional gasoline manifold of a phosphoric acid type fuel cell. Gas supply and discharge of a gas manifold mounted on a cell stack arranged on the left side of FIG. Is a cross-sectional view of a connecting portion of a piping for use. In the figure, 1 is a manifold side plate forming a gas manifold body, 11 is a nozzle pipe with a flange welded to the manifold side plate 1 for connecting gas supply and discharge pipes, and 2 is a nozzle hole.
The connecting pipe 8 for supplying gas from the outside or discharging the gas to the outside and the nozzle pipe 11 are connected to the fastening stud 1.
0 is flanged. In order to prevent corrosion by phosphoric acid mist, an anticorrosion sheet 4 is provided on the inner surface of the manifold side plate 1, and a nozzle lining 12 is provided on an inner surface of the nozzle pipe 11. Further, the nozzle lining 12 is fused to the anticorrosion sheet 4 at the fusion portion 5D. The connection pipe 8 is also provided with a pipe lining 9 for preventing corrosion by phosphoric acid mist, and the connection flange of the nozzle pipe 11 is connected to the connection pipe 8.
PTF with a U-shaped cross section
P in which cushioning material 7 is stored in outer shell 13 of E ring
A TFE wrapped gasket is used. The PTFE-wrapped gasket has a characteristic that the cushioning material 7 absorbs the unevenness of the flange surface so that the sealing performance can be secured even at a low tightening pressure, and is generally marketed as a gasket for connecting a lining pipe. In such a commercially available gasket, PTFE having a thickness of about 0.1 to 0.5 mm is usually used as the outer cover 13.

[0004]

As described above, the pipe connection of the gas manifold of the conventional phosphoric acid type fuel cell is provided with the flange of the nozzle pipe 11 provided with the nozzle lining 12 and the pipe lining 9. A gasket wrapped with PTFE is arranged between the connection pipe 8 and the flange of the connection pipe 8 so as to prevent corrosion by phosphoric acid mist.
Is performed by passing a pipe made of PTFE through the inside of the nozzle pipe 11 and then flaring the gasket surface of the flange portion. The joint portion with the anticorrosion sheet 4 arranged on the inner surface of the gas manifold side plate 1 is joined by welding when the anticorrosion sheet 4 is thick, and made of PTFE that passes through the inside of the nozzle pipe 11 when the anticorrosion sheet 4 is thin. Are joined by the same flaring process as the gasket surface of the flange portion.

As described above, in the conventional gas manifold of the phosphoric acid type fuel cell, the nozzle pipe 1
In the construction of the anticorrosion nozzle lining 12 to 1
Since flare processing is required, there is a problem that the manufacturing cost of the gas manifold increases. SUMMARY OF THE INVENTION An object of the present invention is to provide a gasoline manifold for a phosphoric acid-type fuel cell which can solve the above-mentioned drawbacks of the prior art, facilitates anticorrosion treatment of a pipe connection portion, and can be manufactured at low cost.

[0006]

In order to achieve the above object, according to the present invention, in a gas manifold mounted for supplying and discharging gas to and from a cell stack of a phosphoric acid type fuel cell, a gas manifold is provided. The connection flange surface of the gas supply / discharge lining pipe connected to the gas manifold is connected to the provided connection flange surface having the anticorrosion sheet lining on the upper surface, and the connection flange of the gas manifold is provided. A cushion sheet is interposed between the surface and the above-mentioned anticorrosion sheet lining, and the above-mentioned anticorrosion sheet lining is formed by PTF manufactured by molding or cutting.
It consists of an E ring. Alternatively, it is configured by a PTFE ring manufactured from a sheet.

As described above, a cushion sheet is interposed on the connection flange surface of the gas manifold to provide an anticorrosion sheet lining, and a connection flange surface of a lining pipe for gas supply and discharge is fastened and connected to this surface. if,
Due to the function of the cushion sheet, the anticorrosion sheet lining is pressed against the lining of the connection flange surface of the lining pipe for gas supply and discharge, keeps airtight, and has the same function as the PTFE wrapped gasket used in the conventional configuration. It will be. Therefore, the anticorrosion treatment of the pipe connection can be easily performed without using a conventional PTFE wrapped gasket or a flanged nozzle for incorporating the same.

[0008]

FIG. 1 is a sectional view showing a basic structure of a first embodiment of a gas manifold for a phosphoric acid type fuel cell according to the present invention, similar to the conventional example of FIG. FIG. 3 is a cross-sectional view of a gas supply / discharge pipe connection portion of a gas manifold mounted on a battery stack arranged on the left side of the drawing. In the figure, components having the same functions as those in FIG. 4 are denoted by the same reference numerals, and redundant description will be omitted.

In this configuration, a nozzle flange 3 is provided at a portion of the manifold side plate 1 where the nozzle hole 2 is formed, and the nozzle flange 3 is formed thick to prevent deformation at the time of tightening. Nozzle hole 2 of nozzle flange 3
, A PTFE ring 6A having a U-shaped cross section manufactured by molding is fitted as an anticorrosion sheet lining. One end of a side of the U-shaped cross section of the PTFE ring 6A is The gasket surface of the nozzle flange 3 connected to the external connection pipe 8 provided with the pipe lining 8,
At A, it is fused to the anticorrosion sheet 4 arranged on the inner surface of the manifold side plate 1. Furthermore, a PTFE ring 6
A cushion sheet 7 similar to that used in the conventional example is inserted between the nozzle flange 3 and the portion of the nozzle flange 3 arranged on the gasket surface. The connection pipe 8 provided with the pipe lining 8 is connected as a structure having airtightness and anticorrosion by pressing and fastening the connection flange to the nozzle flange 3 with the fastening stud 10. With this configuration, there is no need to incorporate a PTFE-wrapped gasket as in the conventional example or a flanged nozzle for incorporating the gasket, and the piping connection can be formed at low cost.

In this configuration, the PTFE ring 6A manufactured by molding is used as the anticorrosion sheet lining, but the PTFE ring having the same function can be manufactured by cutting. <Embodiment 2> FIG. 2 is a cross-sectional view showing a basic structure of a gas manifold for a phosphoric acid fuel cell according to a second embodiment of the present invention. As in FIG. 1 shows a cross section of a connection portion of a gas supply / discharge pipe of a gas manifold attached to a gas manifold.

The difference between this embodiment and the first embodiment is that the shape of the PTFE ring fitted as an anticorrosion sheet lining inside the nozzle flange 3 facing the nozzle hole 2 and the PTFE ring and the manifold side plate 1 It has a connection structure with the anticorrosion sheet 4 arranged on the inner surface. That is, while the PTFE ring 6A having a U-shaped cross section is used in the first embodiment, the Z
PTFE ring 6B formed to have a U-shaped cross section
And one end thereof is fused to the anticorrosion sheet 4 at a fusion portion 5 </ b> B protruding inward from the peripheral edge of the nozzle hole 2. In this configuration, as in the first embodiment, PTFE
It is not necessary to incorporate a wrapping gasket or a nozzle with a flange for incorporating the gasket, so that the pipe connection can be formed at a low cost, and the anticorrosion sheet 4 does not need to be bent as in the first embodiment. There is an advantage that the gas manifold using the anticorrosion sheet 4 can be easily constructed.

<Embodiment 3> FIG. 3 is a sectional view showing a basic structure of a third embodiment of the gas manifold of the phosphoric acid type fuel cell according to the present invention. FIG. 2 shows a cross section of a connection portion of a gas supply / discharge pipe of a gas manifold mounted on a battery stack provided.

The feature of this embodiment is that the PTFE rings 6A and 6A of the first and second embodiments are used as anticorrosion sheet linings.
A PTFE ring 6C made of a PTFE flat sheet is used in place of B, and one end of the PTFE ring 6C protrudes inward from the peripheral edge of the nozzle hole 2 to form the anticorrosion sheet 4C.
In that it is fused. PTF used in this configuration
Since the ring 6C made of E is obtained by simply cutting out a flat sheet of PTFE, the gas manifold having this configuration can be manufactured particularly inexpensively.

[0014]

As described above, according to the present invention, in a gas manifold mounted for supplying and discharging gas to and from a cell stack of a phosphoric acid type fuel cell, PTFE is provided on an upper surface provided in the gas manifold. The connection flange surface of the gas supply and discharge lining piping connected to the gas manifold is fastened and connected to the connection flange surface having the anticorrosion sheet lining made of stainless steel, and the connection flange surface of the gas manifold and the connection flange surface described above. As we decided to interpose a cushion sheet between the anticorrosion sheet lining,
Corrosion protection can be easily performed without using a conventional PTFE wrapped gasket or a nozzle with a flange to incorporate the gasket, so that the corrosion prevention of the pipe connection is easy and the phosphoric acid type fuel cell can be manufactured at low cost. A gas manifold was obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a basic configuration of a first embodiment of a gas manifold of a phosphoric acid type fuel cell according to the present invention.

FIG. 2 is a sectional view showing a basic configuration of a second embodiment of the gas manifold of the phosphoric acid type fuel cell according to the present invention.

FIG. 3 is a sectional view showing a basic configuration of a third embodiment of the gas manifold of the phosphoric acid type fuel cell according to the present invention.

FIG. 4 is a cross-sectional view showing a basic configuration of a pipe connection portion of a gas manifold of a conventional phosphoric acid fuel cell.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Manifold side plate 2 Nozzle hole 3 Nozzle flange 4 Corrosion-proof sheet 5A, 5B, 5C Fusion part 6A, 6B, 6C PTFE ring 7 Cushion sheet 8 Connection piping 9 Piping lining 10 Tightening stud

Claims (3)

[Claims] 1. A gas manifold mounted for supplying and discharging gas to and from a cell stack of a phosphoric acid fuel cell, wherein a gas is provided on a connection flange surface of the gas manifold having an anticorrosion sheet lining on an upper surface. A connection flange surface of a gas supply / discharge lining pipe connected to the manifold is fastened and connected, and a cushion sheet is interposed between the connection flange surface provided in the gas manifold and the anticorrosion sheet lining. A gas manifold for a phosphoric acid fuel cell, wherein the gas manifold is formed. 2. The anticorrosion sheet lining is formed by molding,
2. A ring made of polytetrafluoroethylene manufactured by cutting.
The gas manifold of the phosphoric acid type fuel cell according to 1. 3. The gas manifold according to claim 1, wherein the anticorrosion sheet lining is made of a polytetrafluoroethylene ring manufactured from a sheet.