KR102775074B1 - Fuel cell stack and Fuel cell system including the same - Google Patents

Abstract

The present invention relates to a fuel cell stack and a fuel cell system including the same, which can selectively operate the stacks by supplying reaction gases to each of the separated stacks while having the stacks divided into two by a conductive center plate.
According to one embodiment of the present invention, a fuel cell stack is formed by stacking a plurality of unit cells, and includes: a first stack module and a second stack module in which a plurality of unit cells are stacked; a first end plate disposed on one side of the first stack module; a second end plate disposed on one side of the second stack module; and a center plate disposed between the other side of the first stack module and the other side of the second stack module, and connecting the first stack module and the second stack module in series while dividing the first stack module and the second stack module.

Description

Fuel cell stack and fuel cell system including the same {Fuel cell stack and fuel cell system including the same}

The present invention relates to a fuel cell stack and a fuel cell system including the same, and more particularly, to a fuel cell stack and a fuel cell system including the same, wherein the stack is provided so as to be divided into two by a conductive center plate, and a reaction gas is supplied to each of the separated stacks to selectively operate the stacks.

A fuel cell is a type of power generation device that converts the chemical energy of fuel into electrical energy by electrochemically reacting it within a stack. It can be used to supply power for industrial, household, and vehicle driving, as well as for small electronic products such as portable devices. Recently, its use has been gradually expanding as a high-efficiency, clean energy source.

Figure 1 is a diagram showing the configuration of a typical fuel cell stack.

As can be seen in Fig. 1, a typical fuel cell stack is formed by stacking a plurality of unit cells, each of which has a membrane-electrode assembly (MEA) positioned at the innermost part, and this membrane-electrode assembly (100) is composed of a polymer electrolyte membrane (110) capable of moving hydrogen cations (protons), and a catalyst layer applied on both sides of the electrolyte membrane so that hydrogen and oxygen can react, i.e., a fuel electrode (120: anode) and an air electrode (130: cathode).

In addition, a gas diffusion layer (200, GDL: Gas Diffusion Layer) is laminated on the outer part of the membrane electrode assembly (100), that is, the outer part where the fuel electrode (120) and the air electrode (130) are located, and a separator (300) having a flow field formed therein to supply fuel and discharge water generated by the reaction is positioned with a gasket (400, Gasket) interposed therebetween, and an end plate (500, End Plate) is coupled to the outermost part to support and fix the above-described respective components.

Accordingly, in the fuel electrode (120) of the fuel cell stack, an oxidation reaction of hydrogen occurs, generating hydrogen ions (protons) and electrons. The hydrogen ions and electrons generated at this time move to the air electrode (130) through the electrolyte membrane (110) and the wire, respectively. In the air electrode (130), water is generated through an electrochemical reaction involving the hydrogen ions and electrons moved from the fuel electrode (120) and oxygen in the air, and electrical energy is generated from the flow of electrons.

A fuel cell stack produces approximately 200 W of output per unit cell when in operation, and the number of unit cells is determined according to the purpose and required output and connected in series to form a stack.

Recently, as the required output increases, the number of stacked unit cells is gradually increasing.

However, as the number of unit cells increases, the volume of the stack increases. The increase in the volume of the stack means that the length of the stack increases, and accordingly, the length of the manifold that supplies the reaction gas and cooling water increases, causing a deviation in the amount of reaction gas supplied to each unit cell, and the farther the unit cell is from the manifold inlet, the more the generated water accumulates, resulting in secondary problems such as generated water removal and heat management.

The content described as background technology above is only for understanding the background of the present invention, and should not be taken as an acknowledgment that it corresponds to prior art already known to those skilled in the art.

Japanese Patent Publication No. 4505204 (April 30, 2010) Korean Patent Publication No. 10-1184930 (2012.09.06)

The present invention provides a fuel cell stack and a fuel cell system including the same, which can selectively operate the stacks by supplying reaction gases to each of the separated stacks while having the stacks divided into two by a conductive center plate.

According to one embodiment of the present invention, a fuel cell stack is formed by stacking a plurality of unit cells, and includes: a first stack module and a second stack module in which a plurality of unit cells are stacked; a first end plate disposed on one side of the first stack module; a second end plate disposed on one side of the second stack module; and a center plate disposed between the other side of the first stack module and the other side of the second stack module, and connecting the first stack module and the second stack module in series while dividing the first stack module and the second stack module.

The center plate is characterized in that a current collecting area is formed that connects the first stack module and the second stack module in series, an insulation area is formed around the current collecting area, and a plurality of inlet manifold areas and discharge manifold areas are formed in the insulation area, which are selectively connected to a plurality of inlet manifolds and discharge manifolds formed in the first stack module and the second stack module.

The first stack module and the second stack module are respectively formed with a hydrogen inlet manifold, a coolant inlet manifold, an air inlet manifold, a hydrogen exhaust manifold, a coolant exhaust manifold, and an air exhaust manifold, and the center plate is respectively formed with a hydrogen inlet manifold region, a coolant inlet manifold region, an air inlet manifold region, a hydrogen exhaust manifold region, a coolant exhaust manifold region, and an air exhaust manifold region which selectively connect the hydrogen inlet manifold, the coolant inlet manifold, the air inlet manifold, the hydrogen exhaust manifold, the coolant exhaust manifold region, and the air exhaust manifold region formed in the first stack module and the second stack module, wherein the hydrogen inlet manifold region, the coolant inlet manifold region, the air inlet manifold region, the hydrogen exhaust manifold region, the coolant exhaust manifold region, and the air exhaust manifold region are characterized in that they are selectively penetrated.

Meanwhile, a fuel cell system according to one embodiment of the present invention includes: a first stack module and a second stack module in which a plurality of unit cells are stacked; a first end plate disposed on one side of the first stack module; a second end plate disposed on one side of the second stack module; a center plate disposed between the other side of the first stack module and the other side of the second stack module and connecting the first stack module and the second stack module in series while distinguishing the first stack module and the second stack module; a motor operated by electricity generated in at least one stack module among the first stack module and the second stack module; and a relay selectively opening and closing an electric circuit between the first stack module, the second stack module, and the motor.

It includes a first wiring electrically connecting the first end plate and the motor; a second wiring electrically connecting the center plate and the relay; and a third wiring electrically connecting the second end plate and the motor while connecting the relay connected to the second wiring.

It is characterized in that a first switch is connected to the first wiring, a second switch is connected to the second wiring, and an electric means operated by electricity generated in the first stack module and the second stack module is connected to the third wiring.

It further includes a hydrogen supply means, a cooling water supply means and an air supply means for supplying hydrogen, cooling water and air to at least one of the first end plate and the second end plate, respectively.

According to an embodiment of the present invention, by dividing a stack in which a plurality of unit cells are laminated by a conductive center plate, and electrically connecting a first stack module and a second stack module, which are separated on both sides by the center plate, in series, it is expected that the first stack module and the second stack module can be operated individually or together according to a required output.

Accordingly, by avoiding low current operation conditions when only half of the stack is used, flooding can be prevented by preventing accumulation of generated water within the stack, and cell durability can be improved by avoiding high potentials as current usage increases and voltage decreases.

In addition, the distribution of the reaction gas and the cooling water can be improved by individually supplying the reaction gas and the cooling water to the first stack module and the second stack module, which are separated on both sides by the center plate, thereby improving performance stabilization and durability.

Figure 1 is a drawing showing the configuration of a typical fuel cell stack.
Figures 2 and 3 are drawings showing a fuel cell system according to one embodiment of the present invention.
FIG. 4 is a drawing showing a center plate according to one embodiment of the present invention;
FIGS. 5 and 6 are drawings showing examples of implementing a fuel cell system according to one embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and these embodiments are provided only to make the disclosure of the present invention complete and to fully inform a person having ordinary skill in the art of the scope of the invention. In the drawings, the same reference numerals refer to the same elements.

FIGS. 2 and 3 are drawings showing a fuel cell system according to one embodiment of the present invention, and FIG. 4 is a drawing showing a center plate according to one embodiment of the present invention.

As illustrated in the drawing, a fuel cell system according to one embodiment of the present invention comprises a first stack module (S1) and a second stack module (S2) that are connected in series to each other and selectively operated, an electrical wiring means that enables selective operation of the first stack module (S1) and the second stack module (S2) is provided, and a reaction gas and cooling water supply means that enables selective operation of the first stack module (S1) and the second stack module (S2) is provided.

The first stack module (S1) and the second stack module (S2), which are fuel cell stacks (10) constituting the fuel cell system, are elements each configured by stacking a plurality of unit cells, and each unit cell is applied to a unit cell applied to a general fuel cell stack. For example, each unit cell is configured by including an electrode membrane assembly, a pair of gas diffusion layers, and a pair of separators, and each unit cell is configured by connecting a plurality of unit cells in series.

At this time, the number of unit cells stacked on the first stack module (S1) and the second stack module can be configured to be the same, but the number can be set differently so that the output amounts output from the first stack module (S1) and the second stack module (S2) can be set differently.

And, a plurality of inlet manifolds and discharge manifolds for introducing and discharging reaction gas and cooling water are formed in the first stack module (S1) and the second stack module (S2), respectively. For example, a hydrogen inlet manifold, a cooling water inlet manifold, an air inlet manifold, a hydrogen discharge manifold, a cooling water discharge manifold, and an air discharge manifold are formed in the first stack module (S1) and the second stack module (S2), respectively.

Meanwhile, a conductive center plate (13) is interposed between the first stack module (S1) and the second stack module (S2) so that the first stack module (S1) and the second stack module (S2) can be selectively driven while being connected in series.

To elaborate, a first end plate (11) is arranged on one side of the first stack module (S1), a second end plate (12) is arranged on one side of the second stack module (S2), and a center plate (13) is arranged between the other side of the first stack module (S1) and the other side of the second stack module (S2).

At this time, the first end plate (11) and the second end plate (12) are applied as end plates placed at both ends of a general fuel cell stack.

However, the center plate (13) is conductive so that the first end plate (11) and the second end plate (12) are connected in series, and the reaction gas and cooling water supplied to the first end plate (11) and the second end plate (12) can be individually supplied.

To this end, as illustrated in Fig. 4, a center plate (13) is formed with a current collecting area (13b) that connects the first stack module (S1) and the second stack module (S2) in series, and an insulating area (13a) is formed around the current collecting area (13b). Thus, the first stack module (S1) and the second stack module (S2) are electrically connected in series through the current collecting area (13b).

And in the insulation region (13a), a plurality of inlet manifold regions (14a, 15a, 16a) and discharge manifold regions (14b, 15b, 16b) are formed, which are selectively connected to a plurality of inlet manifolds and discharge manifolds formed in the first stack module (S1) and the second stack module (S2).

For example, a hydrogen inlet manifold region (14a), a coolant inlet manifold region (15a), an air inlet manifold region (16a), a hydrogen exhaust manifold region (14b), a coolant exhaust manifold region (15b), and an air exhaust manifold region (16b) are formed in the center plate (13). However, the hydrogen inlet manifold region (14a), the coolant inlet manifold region (15a), the air inlet manifold region (16a), the hydrogen exhaust manifold region (14b), the coolant exhaust manifold region (15b), and the air exhaust manifold region (16b) formed in the center plate (13) are selectively penetrated or closed.

At this time, a plurality of inlet manifold regions (14a, 15a, 16a) and discharge manifold regions (14b, 15b, 16b) formed on the center plate (13) are formed at positions where the corresponding inlet manifolds and discharge manifolds formed on the first stack module (S1) and the second stack module (S2) are formed.

For example, the hydrogen inlet manifold area (14a) formed on the center plate (13) is formed at a position that connects the hydrogen inlet manifolds formed on the first stack module (S1) and the second stack module (S2). Similarly, the coolant inlet manifold area (15a) formed on the center plate (13) is formed at a position that connects the coolant inlet manifolds formed on the first stack module (S1) and the second stack module (S2).

Likewise, the air inlet manifold region (16a), the hydrogen exhaust manifold region (14b), the coolant exhaust manifold region (15b), and the air exhaust manifold region (16b) are formed at positions that connect the air inlet manifold, the hydrogen exhaust manifold, the coolant exhaust manifold, and the air exhaust manifold formed in the first stack module (S1) and the second stack module (S2), respectively.

Meanwhile, electrical wiring means are provided that can selectively drive the first stack module (S1) and the second stack module (S2).

For example, as shown in FIGS. 2 and 3, it includes a motor (20) operated by electricity generated from at least one of the first stack module (S1) and the second stack module (S2); and a relay (30) selectively opening and closing an electric circuit between the first stack module (S1), the second stack module (S2), and the motor (20).

And, it includes a first wiring (60a) that electrically connects the first end plate (11) and the motor (20); a second wiring (60b) that electrically connects the center plate (13) and the relay (30); and a third wiring (60c) that electrically connects the second end plate (12) and the motor (20) while connecting the relay (30) connected to the second wiring (60b).

Therefore, the electric circuit is configured to drive only the first stack module (S1) or to drive both the first stack module (S1) and the second stack module (S2) by controlling the relay (30). Accordingly, the motor (20) can be driven only by driving the first stack module (S1), and the motor (20) can be driven by driving both the first stack module (S1) and the second stack module (S2).

Meanwhile, a first switch (50a) is connected to the first wiring (60a), and a second switch (50b) is connected to the second wiring (60b). In addition, an electric field means (40) operated by electricity generated in the first stack module (S1) and the second stack module (S2) can be connected to the third wiring (60c).

At this time, the electrical means (40) refers to various electrical components used in the vehicle. At this time, the electrical means (40) may be one or more electrical components, and may be a battery that is charged with electricity provided to the electrical components.

Therefore, depending on the opening and closing of the relay (30), the first switch (50a), and the second switch (50b), various modes can be implemented, such as driving only the first stack module (S1), driving only the second stack module (S2), or driving both the first stack module (S1) and the second stack module (S2) together.

And, a hydrogen supply means (70), a cooling water supply means (80), and an air supply means (90) are provided to supply hydrogen, cooling water, and air to at least one of the first end plate (11) and the second end plate (12), respectively.

At this time, the hydrogen supply means (70), the coolant supply means (80), and the air supply means (90) are configured to supply hydrogen, coolant, and air to the first end plate (11) and the second end plate (12), respectively, and depending on whether the hydrogen inlet manifold area (14a), the coolant inlet manifold area (15a), and the air inlet manifold area (16a) formed in the center plate (13) are selectively penetrated and closed, it is possible to select whether to supply hydrogen, coolant, and air to the first end plate (11) and/or the second end plate (12).

An example of implementing a fuel cell system according to one embodiment of the present invention configured as described above will be described with reference to the drawings.

FIGS. 5 and 6 are drawings showing examples of implementing a fuel cell system according to one embodiment of the present invention.

First, when supplying hydrogen, coolant, and air to the first stack module (S1) and the second stack module (S2), respectively, the hydrogen inlet manifold area (14a), the coolant inlet manifold area (15a), the air inlet manifold area (16a), the hydrogen discharge manifold area (14b), the coolant discharge manifold area (15b), and the air discharge manifold area (16b) formed in the center plate (13) are all configured to be closed, and the hydrogen supply means (70), the coolant supply means (80), and the air supply means (90) are configured to supply hydrogen, coolant, and air to the first end plate (11) and the second end plate (12), respectively.

Therefore, hydrogen, cooling water and air supplied from the hydrogen supply means (70), cooling water supply means (80) and air supply means (90) are supplied to the first end plate (11) and the second end plate (12), respectively, and are individually introduced into the first stack module (S1) and the second stack module (S2) and then discharged.

If hydrogen and air are individually introduced and discharged from the first stack module (S1) and the second stack module (S2), while cooling water is introduced and discharged by connecting the first stack module (S1) and the second stack module (S2), a fuel cell system is implemented as shown in FIG. 5.

For example, as illustrated in FIG. 5, the hydrogen inlet manifold region (14a), the air inlet manifold region (16a), the hydrogen discharge manifold region (14b), and the air discharge manifold region (16b) formed in the center plate (13) are configured in a closed state, and the coolant inlet manifold region (15a) and the coolant discharge manifold region (15b) are configured in a penetrating state. In addition, the hydrogen supply means (70) and the air supply means (90) are configured to supply hydrogen and air to the first end plate (11) and the second end plate (12), respectively, and the coolant supply means (80) can supply coolant only to the second end plate (12).

Thus, hydrogen and air can be individually introduced and discharged from the first stack module (S1) and the second stack module (S2), while the cooling water can be introduced and discharged by connecting the first stack module (S1) and the second stack module (S2).

And, in order to individually introduce and discharge coolant and air into and out of the first stack module (S1) and the second stack module (S2), while connecting the first stack module (S1) and the second stack module (S2) to introduce and discharge hydrogen, a fuel cell system is implemented as shown in Fig. 6.

For example, as illustrated in FIG. 6, the coolant inlet manifold region (15a), the air inlet manifold region (16a), the coolant discharge manifold region (15b), and the air discharge manifold region (16b) formed in the center plate (13) are configured in a closed state, and the hydrogen inlet manifold region (14a) and the hydrogen discharge manifold region (14b) are configured in a penetrating state. In addition, the coolant supply means (80) and the air supply means (90) are configured to supply hydrogen and air to the first end plate (11) and the second end plate (12), respectively, and the hydrogen supply means (70) can supply hydrogen only to the second end plate (12).

Thus, while the coolant and air can be individually introduced and discharged from the first stack module (S1) and the second stack module (S2), the hydrogen can be introduced and discharged by connecting the first stack module (S1) and the second stack module (S2).

Although the present invention has been described with reference to the attached drawings and the preferred embodiments described above, the present invention is not limited thereto, but is defined by the claims set forth below. Accordingly, those skilled in the art can variously modify and alter the present invention without departing from the technical spirit of the claims set forth below.

S1: 1st stack module S2: 2nd stack module
10: Fuel cell 11: First end plate
12: 2nd end plate 13: Center plate
13a: Insulation area 13b: Current collection area
14a: Hydrogen inlet manifold area 15a: Coolant inlet manifold area
16a: Air inlet manifold area 14b: Hydrogen exhaust manifold area
15b: Coolant exhaust manifold area 16b: Air exhaust manifold area
20: Motor 30: Relay
40: Battlefield Means 50a: 1st Switch
50b: 2nd switch 60a: 1st wiring
60b: 2nd wire 60c: 3rd wire
70: Hydrogen supply means 80: Cooling water supply means
90: Air supply means

Claims (9)

A fuel cell stack formed by stacking a number of unit cells,
A first stack module and a second stack module in which a plurality of unit cells are stacked;
A first end plate disposed on one side of the first stack module;
A second end plate disposed on one side of the second stack module;
A center plate is disposed between the other side of the first stack module and the other side of the second stack module, and connects the first stack module and the second stack module in series while distinguishing them,
A fuel cell stack characterized in that the outputs of the first stack module and the second stack module are different from each other.
In claim 1,
A fuel cell stack, characterized in that the center plate has a current collecting area formed therein that connects the first stack module and the second stack module in series, an insulation area formed around the current collecting area, and a plurality of inlet manifold areas and exhaust manifold areas selectively connected to a plurality of inlet manifolds and exhaust manifolds formed in the first stack module and the second stack module are formed in the insulation area.
In claim 2,
The first stack module and the second stack module are each formed with a hydrogen inlet manifold, a coolant inlet manifold, an air inlet manifold, a hydrogen exhaust manifold, a coolant exhaust manifold, and an air exhaust manifold,
A fuel cell stack characterized in that a hydrogen inlet manifold region, a coolant inlet manifold region, an air inlet manifold region, a hydrogen exhaust manifold region, a coolant exhaust manifold region, and an air exhaust manifold region are formed on the center plate, which selectively connect the hydrogen inlet manifold, the coolant inlet manifold, the air inlet manifold, the hydrogen exhaust manifold, the coolant exhaust manifold, and the air exhaust manifold region formed on the first stack module and the second stack module, respectively, wherein the hydrogen inlet manifold region, the coolant inlet manifold region, the air inlet manifold region, the hydrogen exhaust manifold region, the coolant exhaust manifold region, and the air exhaust manifold region are selectively penetrated.
A first stack module and a second stack module in which a plurality of unit cells are stacked;
A first end plate disposed on one side of the first stack module;
A second end plate disposed on one side of the second stack module;
A center plate arranged between the other side of the first stack module and the other side of the second stack module, and connecting the first stack module and the second stack module in series while distinguishing them;
A motor driven by electricity generated in at least one of the first stack module and the second stack module;
A relay is included for selectively opening and closing an electric circuit between the first stack module, the second stack module, and the motor.
A fuel cell system characterized in that the outputs of each of the first stack module and the second stack module are different.
In claim 4,
A first wiring electrically connecting the first end plate and the motor;
A second wire electrically connecting the center plate and the relay;
A fuel cell system including a third wire connected to a relay connected to the second wire while electrically connecting the second end plate and the motor.
In claim 5,
The first switch is connected to the above first wiring,
A second switch is connected to the above second wiring,
A fuel cell system characterized in that an electric means operated by electricity generated in the first stack module and the second stack module is connected to the third wiring.
In claim 4,
A fuel cell system further comprising a hydrogen supply means, a cooling water supply means, and an air supply means for supplying hydrogen, cooling water, and air to at least one of the first end plate and the second end plate, respectively.
In claim 1,
The number of unit cells in each of the first and second stack modules is different.
A fuel cell stack characterized by having different outputs of the first stack module and the second stack module.
In claim 4,
The number of unit cells in each of the first and second stack modules is different.
A fuel cell system characterized by having different outputs of the first stack module and the second stack module.

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