JPH04355061A - Fuel cell - Google Patents

Abstract

PURPOSE:To enable gas to uniformly flow by decreasing a sectional area from respective inlet parts to internal parts in supply paths of fuel gas and oxidizer gas and a sectional area from respective outlet parts to internal parts in discharge paths of fuel gas and oxidizer gas. CONSTITUTION:Fuel gas (a) and oxidizer gas (b) are supplied to each supply path 19 of a fuel gas supply path 11 and an oxidizer gas supply path 12 or the like and discharged from each discharge path 20 of a fuel gas discharge path 13 and an oxidizer gas discharge path 14 or the like. Here, tilt parts 23, 26 are provided in a part in a central side of cells 9 in each supply path 19 and discharge path 20. In accordance with advancing to internal parts 22, 25 from a side of inlet and outlet parts 21, 24, a sectional area of a flow path is decreased in accordance with a change of flow amount of the gases (a), (b). In this way, a pressure in the inside of each supply path 19 and discharge path 20 is uniformly generated, and a pressure in inlet/outlet sides of the fuel gas and oxidizer gas flow paths of the cell 9 in each layer is uniformly generated so that the gases (a), (b) are allowed to flow uniformly in each layer cell 9.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molten carbonate fuel cell.

0002

2. Description of the Related Art A conventional fuel cell will be explained below with reference to FIGS. 3 to 7.

[0003] For example, a rectangular electrolyte plate 1 is provided by impregnating a porous material with a carbonate such as lithium carbonate or potassium carbonate, or by press-molding the carbonate together with a holding material.
The electrolyte plate 1 is sandwiched between an anode 2 (anode) and a cathode 3 (cathode), and the anode 2 and cathode 3 are sandwiched between a punch plate 4 in which a large number of holes are punched. A stack 6 is constructed by laminating punch plates 4 in multiple layers with corrugated corrugates 5 and separators 27 interposed therebetween.

At this time, as shown in FIG. 7, the fuel gas a containing hydrogen and carbon monoxide as main components can flow between the corrugated corrugate 5 and the anodes 2 and punch plates 4 of each layer. A gas flow path 7 is formed, and an oxidizing gas flow that allows oxidizing gas b mainly composed of oxygen and carbon dioxide to flow between the corrugated corrugated plate 5 and the cathode 3 and punch plate 4 of each layer. A channel 8 is formed, and a structural unit of the stack 6 called a cell 9 is formed by the fuel gas channel 7, punch plate 4, anode 2, electrolyte plate 1, cathode 3, punch plate 4, and oxidant gas channel 8. .

The anode 2, cathode 3, and punch plate 4 are formed into a frame-shaped mask plate 10 that is smaller than the electrolyte plate 1 and whose planar shape is shown in FIG.
is housed in.

The stack 6 having the above structure includes cells 9 in each layer.
As shown in FIGS. 6 and 7, one end of the fuel gas flow path 7 and the oxidant gas flow path 8 is formed by vertically penetrating the electrolyte plate 1, the mask plate 10, and the separator 27. Fuel gas supply passages 11 communicating with each other and oxidizing gas supply passages 12 communicating with the oxidizing gas passage 8 are formed alternately (see FIG. 4).

Similarly, on the other end side of the fuel gas flow path 7 and the oxidant gas flow path 8 in the cells 9 of each layer, there is a fuel gas flow path 7 and a fuel gas flow path that vertically penetrate the electrolyte plate 1, the mask plate 10, and the separator 27. A fuel gas discharge path 13 that is communicated with, and
Oxidizing gas discharge passages 14 communicating with the oxidizing gas passages 8 are formed alternately (see FIG. 4).

[0008]Furthermore, as shown in FIG.
The fuel gas supply port 15 and the oxidant gas supply port 16, which supply and discharge fuel gas a and oxidant gas b, respectively, to the lower side of the stack 6, and the fuel gas exhaust port An outlet 17 and an oxidizing gas outlet 18 are formed.

Then, the fuel gas a supplied from the fuel gas supply port 15 on the lower side of the stack 6 to the fuel gas supply path 11 is distributed to the fuel gas flow path 7 in the cell 9 of each layer, and the fuel gas flow path of each layer is 7 contacts the anode 2 through the hole in the mask plate 10 and contributes to the reaction at the anode 2, and then is collected from the fuel gas flow path 7 in the cells 9 of each layer to the fuel gas discharge path 13, and the fuel in the lower side of the stack 6 The oxidizing gas b discharged from the gas exhaust port 17 and supplied to the oxidizing gas supply path 12 from the oxidizing gas supply port 16 on the lower side of the stack 6 is sent to the oxidizing gas flow path 8 in the cells 9 of each layer. The oxygen-containing gas is distributed, contacts the cathode 3 through the hole in the mask plate 10 in the oxidant gas flow path 8 of each layer, and contributes to the reaction at the cathode 3, and then flows from the oxidant gas flow path 8 in the cell 9 of each layer to the oxidant gas discharge path. 14 and is discharged from the oxidizing gas outlet 18 on the lower side of the stack 6, and at this time, the reaction between the anode 2 and the cathode 3 is caused by the reaction a of the fuel gas at the anode 2 and the reaction of the oxidizing gas b at the cathode 3. Electricity is generated by the potential difference created between the two.

0010

[Problems to be Solved by the Invention] However, the above conventional fuel cells have the following problems.

That is, each supply path such as the fuel gas supply path 11 and the oxidizing gas supply path 12, and each exhaust path such as the fuel gas exhaust path 13 and the oxidizing gas exhaust path 14, are used to supply the cells 9 of each layer. An inlet portion (fuel gas supply port 15, oxidant gas supply port 16, and fuel gas discharge port 1) through which a large amount of fuel gas a before distribution and oxidant gas b after gathering from cells 9 of each layer flows
7) near the oxidizing gas discharge port 18 side) and, conversely, near the inner part where the fuel gas a after being distributed to the cells 9 of each layer and the oxidizing gas b before collecting from the cells 9 of each layer flow slightly. in,
Although the flow rates of fuel gas a and oxidizing gas b were different, the cross-sectional area of each supply path 11, 12 and each discharge path 13, 14 was made uniform from the inlet to the inner part, so that each The pressure in the supply channels 11 and 12 and the discharge channels 13 and 14 is high on the inlet side and low on the inner side, and the pressure on the inlet and outlet sides of the fuel gas flow path 7 and oxidant gas flow path 8 of the cells 9 in each layer is The fuel gas a and the oxidizing gas b become non-uniform, and the fuel gas a and the oxidizing gas b are distributed in the cells 9 of each layer.
There is a problem in that the fuel gas does not flow uniformly through the fuel gas flow path 7 and the oxidizing gas flow path 8, which is an obstacle to increasing the number of stacked cells 9 and increasing the capacity of the fuel cell.

In view of the above-mentioned circumstances, the present invention has been developed to reduce the pressure inside each supply path such as a fuel gas supply path and an oxidant gas supply path, and each exhaust path such as a fuel gas discharge path and an oxidant gas discharge path. The object of the present invention is to provide a fuel cell in which the fuel gas and the oxidant gas can flow uniformly through the fuel gas flow path and the oxidant gas flow path of the cells in each layer.

[0013]

[Means for Solving the Problems] In the present invention, an anode is arranged on one side of an electrolyte plate, a cathode is arranged on the other side of the electrolyte plate, and a fuel gas flow path is provided on the side of the anode opposite to the electrolyte plate. At the same time, an oxidant gas flow path is formed on the surface of the cathode opposite to the electrolyte plate to form a cell, and the cells are laminated in multiple layers to form a stack, and the fuel gas flow path and oxidant gas flow in the stack are A fuel gas supply passage extending in the stacking direction of the stack and communicating with the fuel gas passage of each layer and an oxidizing gas supply passage communicating with the oxidizing gas passage of each layer are formed at one end side of the passage, and the fuel gas flow in the stack is A fuel gas exhaust passage that extends in the stacking direction of the stack and communicates with the fuel gas passage of each layer, and an oxidant gas exhaust passage that communicates with the oxidant gas passage of each layer are formed on the other end side of the passage and the oxidizing gas passage. In the fuel cell, each of the fuel gas supply path and the oxidant gas supply path is provided with an inclined portion whose cross-sectional area decreases as it goes deeper from the inlet, and the fuel gas discharge path and the oxidant gas discharge path are each provided with an inclined portion whose cross-sectional area decreases as it goes deeper. The present invention relates to a fuel cell characterized in that it is provided with an inclined part whose cross-sectional area decreases as it goes from one part to the other part.

[0014]

[Operation] According to the present invention, when fuel gas is supplied to the fuel gas supply path, the fuel gas is dispersed from the fuel gas supply path to the fuel gas flow path of each layer, flows through the fuel gas flow path, and is brought into contact with the anode. After contributing to the reaction at the anode, it is collected and discharged into the fuel gas exhaust channel.

Furthermore, when the oxidant gas is supplied to the oxidant gas supply path, the oxidant gas is dispersed from the oxidant gas supply path to the oxidant gas flow path of each layer, flows through the oxidant gas flow path, and comes into contact with the cathode. After contributing to the reaction at the cathode, it is collected and discharged to the oxidant gas discharge path.

[0016] Electric power is generated by the potential difference generated between the anode and the cathode due to the reaction of the fuel gas at the anode and the reaction of the oxidant gas at the cathode.

[0017] At this time, an inclined part whose cross-sectional area decreases as it goes deeper from the inlet part provided in each of the fuel gas supply passage and the oxidant gas supply passage, and a slope part which is provided in each of the fuel gas supply passage and the oxidant gas discharge passage, and whose cross-sectional area decreases as it goes deeper The fuel gas and oxidant gas flowing inside the fuel gas supply path, the oxidant gas supply path, the fuel gas discharge path, and the oxidant gas discharge path are Since the pressure difference from the inlet and outlet to the inner part is eliminated or reduced, the fuel gas and the oxidizing gas flow evenly into the fuel gas passages of each layer and the oxidizing gas passages of each layer.

[0018]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention.

Further, in the drawings, the same components as those in FIGS. 3 to 7 are given the same reference numerals, and the explanation thereof will be omitted, and only the structures unique to the present invention will be explained below.

[0021] Fuel gas supply path 11 and oxidant gas supply path 1
In each supply path 19 such as 2, the fuel gas a is added to the central part of the cell 9 as it progresses from the inlet part 21 side to the inner part 22 side.
and an inclined portion 23 that reduces the cross-sectional area of the flow path according to changes in the flow rate of the oxidant gas b.

Similarly, in each discharge passage 20 such as the fuel gas discharge passage 13 and the oxidant gas discharge passage 14, the fuel gas a and A slope portion 26 is provided to reduce the cross-sectional area of the flow path according to a change in the flow rate of the oxidant gas b.

Each supply path 19 has an inlet portion 21 on the bottom side and a deep portion 22 on the top side, and each discharge path 20 has an outlet portion 24 on the top side and a deep portion 25 on the bottom side.

Next, the operation will be explained.

The process of operating the fuel cell is shown in FIGS.
Since it is the same as FIG. 7, the explanation will be omitted.

Fuel gas supply path 11 and oxidant gas supply path 1
When supplying fuel gas a and oxidant gas b to each supply path 19 such as 2, etc., and from each exhaust path 20 such as fuel gas discharge path 13 and oxidant gas discharge path 14, fuel gas a and oxidant gas b are When discharging, slope portions 23 and 26 are provided in the central portion of the cell 9 in each supply path 19 and each discharge path 20,
Since the flow passage cross-sectional area is reduced in accordance with the change in the flow rate of fuel gas a and oxidizing gas b as it advances from the inlet part 21 and outlet part 24 side to the inner parts 22 and 25 side, each supply path 19 and The pressure inside each discharge passage 20 is equalized, and therefore the pressure on the inlet and outlet sides of the fuel gas passage 7 and oxidant gas passage 8 of the cells 9 of each layer is equalized, so that the fuel gas a and the oxidant gas b are equalized. are the fuel gas passages 7 and oxidant gas passages 8 of the cells 9 in each layer.
It will flow evenly.

[0027] This makes it possible to manufacture a compact, large-capacity, high-performance fuel cell by arbitrarily increasing the number of stacked cells 9.

Furthermore, since the inlet portion 21 of each supply path 19 is placed on the lower side and the inner portion 22 is placed on the upper side, the outlet portion 24 of each discharge path 20 is placed on the upper side and the inner portion 25 is placed on the lower side. Fuel gas passages 7 and oxidant gas passages 8 of cells 9 in each layer
The length becomes constant, which is advantageous for mass production.

FIG. 2 shows a second embodiment of the present invention, which has the same structure as the previous embodiment except that the outlet 24 of the discharge passage 20 is placed on the lower side and the inner part 25 is placed on the upper side. Therefore, by arbitrarily increasing the number of stacked cells 9, it becomes possible to manufacture a small-sized, large-capacity, high-performance fuel cell.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

[0031]

Effects of the Invention As explained above, according to the fuel cell of the present invention, each supply path such as a fuel gas supply path and an oxidant gas supply path, as well as a fuel gas discharge path and an oxidant gas discharge path, By making the pressure inside each discharge path uniform, an excellent effect can be achieved in that the fuel gas and the oxidant gas can be uniformly flowed through the fuel gas flow path and the oxidant gas flow path of the cells in each layer.

[Brief explanation of drawings]

FIG. 1 is an overall schematic side view of a first embodiment of the present invention.

FIG. 2 is an overall schematic side view of a second embodiment of the present invention.

FIG. 3 is an overall schematic side view of a conventional example.

FIG. 4 is a plan view of the mask plate provided in FIG. 3;

5 is a partial cross-sectional view of the fuel cell seen from the V-V direction in FIG. 4. FIG.

6 is a partial cross-sectional view of the fuel cell seen from the direction VI-VI in FIG. 4. FIG.

7 is a partial cross-sectional view of the fuel cell seen from the direction VII-VII in FIGS. 5 and 6. FIG.

[Explanation of symbols]

1 Electrolyte plate 2 Anode 3 Cathode 6 Stack 7 Fuel gas flow path 8 Oxidizing gas flow path 9 cell 11 Fuel gas supply path 12 Oxidizing gas supply path 13 Fuel gas exhaust path 14 Oxidizing gas discharge path 21 Entrance section 22, 25 Back 23, 26 Slope part 24 Exit part

Claims (1)

[Claims] Claim 1: An anode is disposed on one side of the electrolyte plate, a cathode is disposed on the other side of the electrolyte plate, a fuel gas flow path is formed on the surface of the anode on the side opposite to the electrolyte plate, and the anti-electrolyte plate of the cathode is disposed on the opposite side of the electrolyte plate. A cell is formed by forming an oxidizing gas flow path on a side surface, a stack is formed by laminating the cells in multiple layers, and the stack is stacked on one end side of the fuel gas flow path and the oxidant gas flow path in the stack. A fuel gas supply passage extending in the direction and communicating with the fuel gas passage of each layer and an oxidizing gas supply passage communicating with the oxidizing gas passage of each layer are formed, and the fuel gas passage and the oxidizing gas passage in the stack are formed. In a fuel cell in which a fuel gas exhaust passage extending in the stacking direction of the stack and communicating with the fuel gas passage of each layer and an oxidizing gas exhaust passage communicating with the oxidizing gas passage of each layer are formed on the other end side, the fuel gas is supplied. Each of the fuel gas discharge passage and the oxidant gas supply passage is provided with an inclined part whose cross-sectional area decreases as it progresses from the inlet to the inner part, and the fuel gas discharge passage and the oxidant gas discharge passage are each provided with an inclined part that decreases in cross-sectional area as they proceed from the outlet to the inner part. A fuel cell characterized by having a sloped portion whose area decreases.