TWI594491B - Bipolar plate and fuel cell stack unit - Google Patents

Description

Bipolar plate and fuel cell stack unit

The present invention relates to a bipolar plate, and more particularly to a bipolar plate and a fuel cell stack unit having different flow path cross-sectional areas.

The fuel cell converts the chemical energy in the fuel into electrical energy, which can provide stable power without charging or replacing. The solid oxide fuel cell (SOFC) can be simply connected to the fuel cell stack by stacking. The unit improves the output of electric energy and has the advantages of long-term stability and low cost, so it is favored in various application fields.

However, under the premise of not changing the structural design of the fuel flow field of the bipolar plate, there is still room for improvement in power density, fuel utilization rate, and power generation efficiency of the existing fuel cell stack unit.

Accordingly, it is an object of the present invention to provide a bipolar plate that overcomes the above-discussed shortcomings of the prior art.

Thus, the bipolar plate of the present invention comprises an anode side and a cathode side disposed opposite the anode side. The anode side has a set of fluid fuel inlet channels, a set of fluid fuel outlet channels, and a communication line a fluid fuel inlet flow path and a fluid fuel flow field of the set of fluid fuel outlet flow passages, the flow path cross-sectional area of the set of fluid fuel inlet flow passages communicating with the fluid fuel flow flow passage being greater than the set of fluid fuels A cross-sectional area of the flow path where the outlet flow path communicates with the fluid fuel flow field. The cathode side has a set of oxygen-containing fluid inlet flow passages, a set of oxygen-containing fluid outlet flow passages, and an oxygen-containing fluid flow field connecting the set of oxygen-containing fluid inlet flow passages and the set of oxygen-containing fluid outlet flow passages.

Another object of the present invention is to provide a fuel cell stack unit comprising two bipolar plates and a laminate as described above. The laminate is disposed between the two bipolar plates, and includes: an anode metal mesh disposed corresponding to the fluid fuel flow field, a cathode metal mesh disposed corresponding to the oxygen-containing fluid flow field, and a cathode metal layer disposed on the anode metal a SOFC unit cell between the net and the cathode metal mesh, the boundary of the anode metal mesh being defined by the SOFC unit cell, the fluid fuel flow field and an anode sealing region The boundary of the cathode metal mesh is defined by the SOFC unit cell, the oxygen-containing fluid flow field and a cathode sealing zone.

The effect of the invention is that the bipolar plate can improve the flow uniformity of the fluid fuel, and improve the maximum power density, fuel utilization rate and power generation efficiency of the fuel cell stack unit.

The present invention will be described in detail below. Preferably, the set of fluid fuel inlet flow passages and the set of fluid fuel outlet flow passages are mutually corresponding linear flow passages, and the set of oxygen-containing fluid inlet flow passages and the set of The linear flow passages of the oxygen fluid outlet flow passages correspond to each other to control the fluid flow direction and have a rectifying action. More preferably, the set of fluid fuel inlet flow channels and the set of fluid fuel outlet flow channels are respectively located on opposite sides of the fluid fuel flow field, the set of oxygen-containing fluid inlet flow paths and The set of oxygen-containing fluid outlet flow channels are respectively located on opposite sides of the oxygen-containing fluid flow field. Still more preferably, the set of fluid fuel inlet flow passages and the set of fluid fuel outlet flow passages extend perpendicularly to the set of oxygen-containing fluid inlet flow passages and the direction in which the set of oxygen-containing fluid outlet flow passages extend.

Preferably, the fluid fuel flow field and the oxygen-containing fluid flow field respectively have a column array arranged in a checkerboard shape to respectively form a mesh network.

Preferably, the material of the anode sealing zone and the cathode sealing zone is selected from glass ceramics, mica or solder alloy to insulate the anode metal mesh and the cathode metal mesh, respectively.

Preferably, the material of the two bipolar plates is stainless steel, such as, but not limited to, SUS 430, SUS 431, SUS 441, and Crofer® 22.

1‧‧‧fuel cell stack unit

2‧‧‧ bipolar plates

24‧‧‧ anode side

241‧‧‧Fluid fuel inlet runner

242‧‧‧Fluid fuel outlet runner

243‧‧‧Fluid fuel flow field

248‧‧‧Anode column array

249‧‧‧Anode flow channel network

25‧‧‧ Cathode side

251‧‧‧Oxygen fluid inlet runner

252‧‧‧Oxygen-containing fluid outlet flow path

253‧‧‧Oxygen-containing fluid flow field

258‧‧‧cathode pillar array

259‧‧‧Cathodic flow channel network

3‧‧‧Layer

33‧‧‧SOFC unit battery

34‧‧‧Anode metal mesh

35‧‧‧Cathed metal mesh

36‧‧‧Anode sealing area

37‧‧‧Cathodic sealing area

4‧‧‧Anode separation module

5‧‧‧Cathode separation module

Other features and effects of the present invention will be apparent from the following description of the drawings, wherein: FIG. 1 is a perspective view of a first embodiment of the fuel cell stack unit of the present invention; [FIG. 2] An exploded perspective view of the first embodiment; [Fig. 3] is an exploded perspective view of a bipolar plate, an anode separation module and a cathode separation module of the first embodiment; FIG. 5 is a cross-sectional view taken along line VV of FIG. 1; FIG. 6 is the bipolar of the first embodiment. A top view of the plate, the anode separation module and the cathode separation module; and [FIG. 7] is a bottom view of the bipolar plate, the anode separation module and the cathode separation module of the first embodiment .

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.

The invention is further described in the following examples, but it should be understood that these examples are for illustrative purposes only and are not to be construed as limiting.

Referring to FIG. 1 to FIG. 3, a first embodiment of the flat type solid oxide fuel cell stack unit 1 of the present invention comprises two bipolar plates 2, a laminate 3, an anode separation module 4 and a cathode separation module 5.

Each bipolar plate 2 includes an anode side 24 and a cathode side 25 disposed opposite the anode side 24.

The anode side 24 has a set of fluid fuel inlet runners 241, a set of fluid fuel outlet runners 242 (see FIG. 7), and a fluid fuel that communicates the set of fluid fuel inlet runners 241 with the set of fluid fuel outlet runners 242. Flow field 243 (see Figure 7). The set of fluid fuel inlet flow passages 241 and the set of fluid fuel outlet flow passages 242 are mutually corresponding linear flow passages and are located on opposite sides of the fluid fuel flow field 243, respectively. The fluid fuel flow field 243 has an anode stud array 248 (see Fig. 7) arranged in a checkerboard shape to form a grid-shaped anode runner network 249 (see Fig. 7).

The cathode side 25 has a set of oxygen-containing fluid inlet channels 251, a set of oxygen-containing fluid outlet channels 252, and an oxygen-containing fluid connecting the set of oxygen-containing fluid inlet channels 251 and the set of oxygen-containing fluid outlet channels 252. Flow field 253. The set of oxygen-containing fluid inlet flow passages 251 and the set of oxygen-containing fluid outlet flow passages 252 are linear flow passages corresponding to each other, and are respectively located at two opposite sides of the oxygen-containing fluid flow field 253. The oxygen-containing fluid flow field 253 has a chess A cathode-arc array 258 (see Fig. 6) is provided in a disk shape to form a grid-like cathode runner network 259 (see Fig. 6).

The set of fluid fuel inlet runners 241 and the set of fluid fuel outlet runners 242 extend perpendicularly to the direction in which the set of oxygenated fluid inlet runners 251 and the set of oxygenated fluid outlet runners 252 extend.

The laminated body 3 is disposed between the two bipolar plates 2, and includes: an anode metal mesh 34 corresponding to the fluid fuel flow field 243, a cathode metal mesh 35 corresponding to the oxygen-containing fluid flow field 253, and An SOFC unit cell 33 disposed between the anode metal mesh 34 and the cathode metal mesh 35, the anode metal mesh 34 is bounded by the SOFC unit cell 33, the fluid fuel flow field 243 and a The anode sealing zone 36 is collectively defined. The boundary of the cathode metal mesh 35 is defined by the SOFC unit cell 33, the oxygen-containing fluid flow field 253 and a cathode sealing zone 37.

In the first embodiment, the anode sealing region 36 and the cathode sealing region 37 are made of glass ceramic to insulate the anode metal mesh 34 and the cathode metal mesh 35, respectively.

Referring to FIGS. 2 to 4 , the anode separation module 4 is disposed on the anode side 24 of the bipolar plate 2 and is detachably embedded in the set of fluid fuel inlet flow passages 241 and the set of fluid fuel outlet passages 242 . (See FIG. 7) and in the same plane as the fluid fuel flow field 243 to sealingly separate the set of fluid fuel inlet runners 241 from the anode seal zone 36 and sealingly separate the set of fluid fuel outlet runners 242 And the anode sealing zone 36, so that the anode sealing zone 36 is evenly stressed when the fuel cell stack unit 1 is packaged, and is not deformed with the set of fluid fuel inlet flow passages 241 and the set of fluid fuel outlet flow passages 242. And avoiding the set of fluid fuel inlet flow passages 241 and the set of fluid fuel outlets The fluid fuel in the flow passage 242 acts or dissolves the material of the anode seal zone 36.

Referring to FIG. 1 to FIG. 3, the cathode separation module 5 is disposed on the cathode side 25 of the bipolar plate 2, and is detachably embedded in the set of oxygen-containing fluid inlet flow passages 251 and the set of oxygen-containing fluid outlet flows. Lane 252 and in the same plane as the oxygen-containing fluid flow field 253 to sealingly separate the set of oxygen-containing fluid inlet flow passages 251 from the cathode seal region 37 and sealingly separate the set of oxygen-containing fluid outlet passages 252 And the cathode sealing zone 37, so that the cathode sealing zone 37 is evenly stressed when the fuel cell stack unit 1 is packaged, so as not to follow the set of oxygen-containing fluid inlet flow channels 251 and the set of oxygen-containing fluid outlet flow channels 252. The deformation and the oxygen-containing fluid inlet flow passage 251 and the oxygen-containing fluid in the set of oxygen-containing fluid outlet passages 252 are prevented from acting or dissolving with the material of the cathode sealing zone 37.

In the first embodiment, the flow path cross-sectional area (about 22.1 mm ² ) at which the set of fluid fuel inlet runners 241 communicate with the fluid fuel flow field 243 is greater than the set of fluid fuel outlet runners 242 and the fluid The cross-sectional area of the flow path at the junction of the fuel flow field 243 (about 13.26 mm ² ).

In the first embodiment, the material of the two bipolar plates 2 is stainless steel, and the anode separation module 4 and the cathode separation module 5 are each two stainless steel sheets, which are resistant to high temperature and have good electrical conductivity at high temperatures. .

Referring to FIGS. 5-7, when the fuel cell stack unit 1 performs power generation, a fluid fuel flows into the fluid fuel flow field 243 from the set of fluid fuel inlet channels 241, and is evenly distributed by the anode stud array 248. Flowing through the anode metal mesh 34, an oxidation reaction occurs in the SOFC unit cell 33, and the remaining fluid fuel flows out of the set of fluid fuel outlet channels 242; meanwhile, an oxygen-containing fluid flows in from the set of oxygen-containing fluid inlet channels 251. The oxygen-containing fluid flow field 253 is evenly distributed by the cathode stud array 258. Flowing through the cathode metal mesh 35, a reduction reaction occurs in the SOFC unit cell 33, and the remaining oxygen-containing fluid flows out of the set of oxygen-containing fluid outlet channels 252.

A second embodiment of a fuel cell stack unit 1 of the present invention is similar to the first embodiment in that the set of fluid fuel inlet flow passages 241 are in communication with the fluid fuel flow field 243 in the second embodiment. The cross-sectional area of the flow path is equal to the cross-sectional area of the flow path where the set of fluid fuel outlet flow passages 242 communicate with the fluid fuel flow field 243 (both about 22.1 mm ² ).

a hydrogen-nitrogen mixed gas (containing 3% water vapor) is introduced from the set of fluid fuel inlet flow passages 241 of the first embodiment and the fuel cell stack unit 1 (single layer) of the second embodiment, respectively, and The oxygen-containing fluid inlet flow passage 251 is passed through dry air for 100 hours, and the maximum power density is measured using an electronic load [set tensile load current of 32.4 A, operating voltage of 0.6 to 0.7 V]. (650 ° C), fuel utilization rate and power generation efficiency (test temperature 620 ° C), the results are shown in Table 1 below.

As can be seen from the above Table 1, the maximum power density, fuel utilization rate and power generation efficiency of the first embodiment are greater than that of the second embodiment, showing that the fluid fuel of the first embodiment is in its fluid fuel flow field 243. Flow uniformity is preferred.

In summary, the bipolar plate 2 of the present invention has a flow passage cross-sectional area at which the fluid fuel inlet flow passage 241 communicates with the fluid fuel flow field 243 is larger than the set of fluid fuel outlet flow passage 242 and the fluid fuel flow. The cross-sectional area of the flow channel at the intersection of field 243, The flow uniformity of the fluid fuel in the fluid fuel flow field 243 is enhanced, thereby increasing the maximum power density, fuel utilization rate, and power generation efficiency of the fuel cell stack unit 1, so that the object of the present invention can be achieved.

However, the above is only the embodiment of the present invention, and the scope of the invention is not limited thereto, and all the equivalent equivalent changes and modifications according to the scope of the patent application and the patent specification of the present invention are still The scope of the invention is covered.

24‧‧‧ anode side

241‧‧‧Fluid fuel inlet runner

25‧‧‧ Cathode side

251‧‧‧Oxygen fluid inlet runner

252‧‧‧Oxygen-containing fluid outlet flow path

253‧‧‧Oxygen-containing fluid flow field

4‧‧‧Anode separation module

5‧‧‧Cathode separation module

Claims (8)

A bipolar plate comprising: an anode side having a plurality of fluid fuel inlet flow passages, a set of fluid fuel outlet flow passages, and a fluid fuel flow field communicating the set of fluid fuel inlet flow passages and the set of fluid fuel outlet flow passages a cross-sectional area of the flow passage of the fluid fuel inlet flow passage communicating with the fluid fuel flow passage is greater than a cross-sectional area of the flow passage of the fluid vapor outlet flow passage and the fluid fuel flow passage; and an anode a side opposite the cathode side, having a set of oxygen-containing fluid inlet flow channels, a set of oxygen-containing fluid outlet flow channels, and an oxygen-containing fluid flow connecting the set of oxygen-containing fluid inlet flow channels and the set of oxygen-containing fluid outlet flow channels field. The bipolar plate according to claim 1, wherein the set of fluid fuel inlet flow passages and the set of fluid fuel outlet flow passages are mutually corresponding linear flow passages, the set of oxygen-containing fluid inlet flow passages and the oxygen-containing group A linear flow path in which fluid outlet flow paths correspond to each other. The bipolar plate of claim 2, wherein the set of fluid fuel inlet flow channels and the set of fluid fuel outlet flow channels are respectively located on opposite sides of the fluid fuel flow field, the set of oxygenated fluid inlet flow paths and The set of oxygen-containing fluid outlet flow channels are respectively located on opposite sides of the oxygen-containing fluid flow field. The bipolar plate of claim 3, wherein the set of fluid fuel inlet flow channels and the set of fluid fuel outlet flow paths extend perpendicular to the set of oxygen-containing fluid inlet flow channels and the set of oxygen-containing fluid outlet flow paths The direction of extension. The bipolar plate according to claim 1, wherein the fluid fuel flow field and the oxygen-containing fluid flow field respectively have a column array arranged in a checkerboard shape to respectively form a mesh network. A fuel cell stack unit comprising: the bipolar plate according to claim 1; and a layer disposed between the two bipolar plates, comprising: an anode metal mesh corresponding to the fluid fuel flow field; a cathode metal mesh corresponding to the flow field of the oxygen-containing fluid and a SOFC unit cell disposed between the anode metal mesh and the cathode metal mesh, the boundary of the anode metal mesh being the SOFC unit cell, the fluid fuel The flow field is defined together with an anode sealing zone, and the boundary of the cathode metal mesh is defined by the SOFC unit cell, the oxygen-containing fluid flow field and a cathode sealing zone. The fuel cell stack unit of claim 6, wherein the material of the anode sealing zone and the cathode sealing zone is selected from the group consisting of glass ceramics, mica or solder alloys. The fuel cell stack unit of claim 6, wherein the material of the two bipolar plates is stainless steel.