KR102496635B1 - Air distribution apparatus for fuel cell system and method for controlling the same - Google Patents

Abstract

An air distribution device of a fuel cell system that variably distributes air flow rates supplied to a first stack module and a second stack module, comprising: a first air supply path for guiding a flow of air supplied to a first stack module; a second air supply path for guiding a flow of air supplied to the second stack module; and a flap rotatably installed between the first air supply path and the second air supply path, wherein the flow path cross-sectional area of the first air supply path and the flow path of the second air supply path are generated by rotation of the flap. The cross-sectional area is relatively variable.

Description

Air distribution device of fuel cell system and its control method {AIR DISTRIBUTION APPARATUS FOR FUEL CELL SYSTEM AND METHOD FOR CONTROLLING THE SAME}

The present invention relates to an air distribution device of a fuel cell system and a control method thereof, and more particularly, to a performance and durability lifespan of two stack modules by variably adjusting the distribution of air flow supplied to two stack modules in various situations. It relates to an air distribution device of a fuel cell system capable of maintaining the same and a control method thereof.

As is generally known, a fuel cell system is a kind of power generation system that directly converts chemical energy of fuel into electrical energy. Such a fuel cell system includes a fuel cell stack generating electrical energy, a fuel supply device supplying fuel (hydrogen) to the fuel cell stack, and an air supply supplying oxygen in the air, which is an oxidizing agent required for an electrochemical reaction, to the fuel cell stack. and a heat and water management device for removing reaction heat from the fuel cell stack to the outside of the system and controlling an operating temperature of the fuel cell stack. Such a fuel cell system generates electricity through an electrochemical reaction between hydrogen as a fuel and oxygen in the air, and emits heat and water as reaction by-products.

In some fuel cell systems, two stack modules are stacked in an enclosure, and a manifold block, which is an interface flow path that equally supplies and discharges air and hydrogen to and from each stack module, may be installed on one side of the enclosure. The manifold block may be hermetically coupled to one side of the enclosure as well as mounting the stack modules.

The manifold block may be configured with an air path (air supply path and air discharge path) and a hydrogen path (hydrogen supply path and hydrogen discharge path) to optimize performance and package. In addition, the manifold block may be modularized by providing a hydrogen shutoff valve, a hydrogen supply valve, a hydrogen purge valve, a water trap, a drain valve, a hydrogen ejector, and the like of the hydrogen supply system.

On the other hand, in the manifold block, one air flow path is divided into two and an air supply path connected to each module is formed so that the air supplied through the humidifier can be divided and supplied to the two stack modules. It is designed to evenly distribute the air into the stacked modules.

However, when a pressure difference (differential pressure) occurs between the two stack modules, the designed distribution amount of air may be distorted. In this way, when the distribution amount of air is distorted due to various variables, performance deviation may occur between the two stack modules, resulting in a problem in that the durability of the two stack modules differs from each other.

The present invention has been devised in view of the above, and by variably adjusting the distribution of the air flow supplied to the two stack modules according to various situations, the fuel that can maintain the same performance and durability of the two stack modules Its purpose is to provide an air distribution device for a battery system and a control method thereof.

One aspect of the present invention for achieving the above object is an air distribution device for a fuel cell system that variably adjusts distribution of air flow rates supplied to a first stack module and a second stack module,

a first air supply path for guiding a flow of air supplied to the first stack module;

a second air supply path for guiding a flow of air supplied to the second stack module; and

A flap rotatably installed between the first air supply path and the second air supply path;

By the rotation of the flap, the passage cross-sectional area of the first air supply passage and the passage cross-sectional area of the second air supply passage are relatively variable.

Another aspect of the present invention is a control method of an air distribution device of a fuel cell system,

When the first air flow rate introduced into the first stack module is greater than the second air flow rate introduced into the second stack module, the flap may be rotated at a predetermined angle toward the first air supply path.

According to the present invention, the flow rate of air supplied to the first stack module and the second stack module can be appropriately distributed by relatively varying the cross-sectional area of the flow path of the first air supply path and the cross-sectional area of the flow path of the second air supply path according to various situations. Through this, there is an advantage in maintaining the same performance and durability of the first and second stack modules.

In addition, the present invention can always uniformly distribute the amount of air supplied to the two stack modules, through which the deterioration of the two stack modules can proceed simultaneously, and in the event of an abnormal situation such as flooding or sudden voltage drop, the air amount can be reduced. By arbitrarily adjusting, each stack module can be easily normalized.

1 is a configuration diagram illustrating a fuel cell system to which an air distribution device according to an embodiment of the present invention is applied.
2 is a view showing an air distribution device according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view taken along line AA of FIG. 2 .
4 is a first use state diagram illustrating a state in which a flap of an air distribution device according to an embodiment of the present invention is rotated toward a first air supply path.
5 is a second use state diagram illustrating a state in which the flam of the air distribution device according to an embodiment of the present invention is rotated toward the second air supply path.
6 is a flowchart illustrating a control method of an air distribution device according to an embodiment of the present invention.
7 is a flowchart illustrating a control method of an air distribution device according to another embodiment of the present invention.
8 is a flowchart illustrating a control method of an air distribution device according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. For reference, the sizes and line thicknesses of components shown in the drawings referred to in describing the present invention may be somewhat exaggerated for convenience of understanding. In addition, the terms used in the description of the present invention are defined in consideration of the functions in the present invention, and may vary depending on the user, operator's intention, convention, and the like. Therefore, the definition of this term should be made based on the contents throughout this specification.

1 illustrates a fuel cell system 1 to which an air distribution device according to an embodiment of the present invention is applicable. The fuel cell system 1 includes a first stack module 11 and a second stack module 12. The installed enclosure (10), the manifold block 15 installed on one side of the enclosure 10, the air supply unit 20 for supplying air to the manifold block 15 side, and the manifold block 15 side A hydrogen supply unit 30 supplying hydrogen may be included.

The first stack module 11 and the second stack module 12 may be stacked inside the enclosure 10 in a vertical direction.

The enclosure 10 may be configured to safely protect the first stack module 11 and the second stack module 12 and to secure sealing properties.

The manifold block 15 includes an air inlet 16 through which air passing through the air supply unit 20 is introduced, an air outlet 17 through which air is discharged from each stack module 11 and 12, and a hydrogen supply unit 30 ) may have a hydrogen inlet 18 through which hydrogen is introduced, and a hydrogen outlet 19 through which hydrogen is discharged from each of the stack modules 11 and 12 .

Inside the manifold block 15, an air supply path for guiding the flow of air supplied to each stack module 11 and 12 and an air discharge path for guiding the flow of air discharged from each stack module 11 and 12 are provided. The path, the hydrogen supply path for guiding the flow of hydrogen supplied to each stack module (11, 12), and the hydrogen discharge path for guiding the flow of hydrogen discharged from each stack module (11, 12) are integrally formed. It can be.

Each of the stack modules 11 and 12 may be configured to stack unit fuel cells having an anode and a cathode. Each stack module (11, 12) has a membrane electrode assembly, and the membrane electrode assembly is an electrolyte membrane capable of moving hydrogen ions (Proton), and a catalyst layer coated on both sides of the electrolyte membrane to allow hydrogen and oxygen to react (ie, cathode and anode).

The air supply unit 20 may include an air supply line 21 connected to the cathode of each stack module 11 and 12 and an air supply unit 22 installed in the air supply line 21 .

The air supply unit 22 is composed of an air blower or an air compressor driven by electric energy, and can forcibly supply air to the cathodes of the respective stack modules 11 and 12 .

An air filter 25 may be installed on the upstream side of the air supply unit 22 .

A humidifier 23 is installed in the middle of the air supply line 21 , and the humidifier 23 may be configured to humidify the air supplied by the air supply unit 22 .

The hydrogen supply unit 30 may include a hydrogen supply line 31 connected to the anodes of each stack module 11 and 12 and a hydrogen supply valve 32 installed in the hydrogen supply line 31 . The supply amount of hydrogen may be determined according to the opening degree of the hydrogen supply valve 32 .

The first stack module 11 and the second stack module 12 may be individually connected to the control unit 40, and the control unit 40 controls the voltage of the first stack module 11 and the second stack module 12. voltage can be monitored individually.

A first flow sensor 41 may be installed in the first stack module 11 , and the air flow rate of the first stack module 11 may be measured in real time by the first flow sensor 41 . A second flow sensor 42 may be installed in the second stack module 12 , and the air flow rate of the second stack module 12 may be measured in real time by the second flow sensor 42 . The first flow sensor 41 and the second flow sensor 42 may be connected to the controller 40, and the controller 40 controls the air flow rate of the first stack module 11 and the second stack module 12. The air flow rate can be monitored in real time.

The air distribution device 50 is a device for distributing the air flow rate supplied to the first stack module 11 and the second stack module 12, and may be provided inside the manifold block 15.

Referring to FIG. 2 , the air distribution device 50 according to the embodiment of the present invention includes a first air supply path 51 and a second air supply path communicating with the air inlet 16 of the manifold block 15 ( 52) may be included.

The first air supply path 51 may be configured to guide the flow of air supplied to the first stack module 11 side, and the second air supply path 52 is the air supplied to the second stack module 12 side. It can be configured to guide the flow of.

The first air supply path 51 and the second air supply path 52 may be configured to branch from the air inlet 16 of the manifold block 15, and the first air supply path 51 and the second air The supply path 52 may be branched so that the distribution ratio of the air flow rate supplied to each of the stack modules 11 and 12 is within 1% of each other.

A flap 55 may be rotatably installed at the branching portion of the first air supply path 51 and the second air supply path 52 . 2 shows a state in which the flap 55 is located in a neutral position. Here, the neutral position means a position where the passage cross-section area of the first air supply passage 51 and the passage cross-sectional area of the second air supply passage 52 are equal to each other.

By the rotation of the flap 55, the cross-sectional area of the flow path of the first air supply path 51 and the cross-sectional area of the flow path of the second air supply path 52 can be relatively changed, and through this, the first stack module 11 and the The air flow rate supplied to the two-stack module 12 can be variably distributed.

The flap 55 can be rotated in both directions (clockwise and counterclockwise) by the driving motor 56, the driving motor 56 is disposed outside the manifold block 15, and the flap 55 is It may be disposed inside the manifold block 15.

According to the embodiment of the present invention, the flap 55 may be formed in a wedge shape with a narrow front end, and the front end of the flap 55 is rotated by the rotation of the flap 55 to the first air supply path 51 And it can move selectively to the second air supply path (52). Accordingly, the passage cross-sectional area of the first air supply passage 51 and the passage cross-sectional area of the second air supply passage 52 can be more precisely changed by the rotation of the flap 55 .

A motor controller 57 is connected to the driving motor 56, and the motor controller 57 can be connected to the side of the controller 40, whereby the motor controller 57 receiving a control signal from the controller 40 is driven. Driving of the motor 56 can be controlled.

When the air flow rate supplied to any one of the first stack module 11 and the second stack module 12 is relatively small, the controller 40 supplies air to the stack module having a relatively large air flow rate. It may be configured to rotate the flap 55 towards the path.

For example, when it is recognized that the air flow rate supplied to the second stack module 12 is distributed smaller than the air flow rate supplied to the first stack module 11 by the controller 40, as shown in FIG. 4, the controller (40) rotates the flap 55 at a predetermined angle toward the first air supply path 51 with a relatively large air flow rate, thereby reducing the cross-sectional area of the passage of the first air supply path 51 and the second air supply path 51. A passage cross-sectional area of the air supply path 52 may be increased. Accordingly, since the air flow rate supplied to the second stack module 12 is relatively increased, the air flow rate supplied to the second stack module 12 and the first stack module 11 can be appropriately distributed.

Conversely, when it is recognized by the control unit 40 that the air flow rate supplied to the first stack module 11 is distributed smaller than the air flow rate supplied to the second stack module 12, as shown in FIG. 5, The control unit 40 rotates the flap 55 at a predetermined angle toward the second air supply path 52 with a relatively large air flow rate, thereby reducing the cross-sectional area of the passage of the second air supply path 52. The cross-sectional area of the passage of the first air supply passage 51 may be increased. Accordingly, since the air flow rate supplied to the first stack module 11 is relatively increased, the air flow rate supplied to the first stack module 11 and the second stack module 12 can be appropriately distributed.

As described above, the present invention provides the first stack module 11 and the second stack module by relatively varying the cross-sectional area of the flow path of the first air supply path 51 and the cross-sectional area of the flow path of the second air supply path 52 according to various situations. The air flow rate supplied to (12) can be appropriately distributed, and through this, the performance and durability of the first and second stack modules 11 and 12 can be maintained the same.

6 is a flowchart illustrating a control method of an air distribution device according to an embodiment of the present invention.

First, the first air flow rate FL1 introduced into the first stack module 11 is measured by the first flow sensor 41, and flowed into the second stack module 12 by the second flow sensor 42. The second air flow rate FL2 is measured (S1).

After receiving the air flow rates FL1 and FL2 from the first flow sensor 41 and the second flow sensor 42, the controller 40 converts the first air flow rate FL1 to the second air flow rate FL2. It is determined whether it is greater than (S2). That is, it is determined whether the air flow rate introduced into the first stack module 11 is greater than the air flow rate introduced into the second stack module 12 .

When it is determined that the first air flow rate FL1 is greater than the second air flow rate FL2, the controller 40 rotates the flap 55 toward the first air supply path 51 at a predetermined rotational angle to supply the second air. The passage sectional area of the passage 52 can be relatively increased, and through this, the air flow rate supplied to the second stack module 12 can be increased (S3).

Here, the rotation angle of the flap 55 may be set to correspond to the difference between the first air flow rate FL1 and the second air flow rate FL2.

If it is determined in step S2 that the first air flow rate FL1 is not greater than the second air flow rate FL2, it is determined whether the second air flow rate FL2 is greater than the first air flow rate FL1 (S4). That is, it is determined whether the air flow rate introduced into the second stack module 12 is greater than the air flow rate introduced into the first stack module 11 .

When it is determined that the second air flow rate FL2 is greater than the first air flow rate FL1, the control unit 40 rotates the flap 55 toward the second air supply path 52 at a predetermined rotational angle to supply the first air. The passage sectional area of the passage 51 can be relatively increased, and through this, the air flow rate supplied to the first stack module 11 can be increased (S5).

In step S4, if the second air flow rate FL2 is not greater than the first air flow rate FL1, it may be determined that the second air flow rate FL2 and the first air flow rate FL1 are equal to each other, and the control unit 40 ) places the flap 55 in a neutral position (S6).

7 is a flowchart illustrating a control method of an air distribution device according to another embodiment of the present invention.

The controller 40 monitors the voltage generation speed VS1 of the first stack module 11 and the voltage generation speed VS2 of the second stack module 12 (S11).

When the air flow rate is sufficiently supplied, the SR (stoichiometric ratio of air) is sufficient, so that the distribution ratio between the air flow rate of the first stack module 11 and the air flow rate of the second stack module 12 differs within 1% However, even if a slight difference in air flow rate between the first stack module 11 and the second stack module 12 occurs during the initial operation of the fuel cell system, a relatively small air flow rate is supplied. The voltage generation speed of the stack module may be slow. Although this occurs for a very short time, if it is repeated frequently, durability life between the first stack module 11 and the second stack module 12 may be different in the long term.

The controller 40 determines whether the voltage generation speed VS2 of the second stack module 12 is slower than the voltage generation speed VS1 of the first stack module 11 (S12). That is, it is determined whether the air flow rate introduced into the second stack module 12 is smaller than the air flow rate introduced into the first stack module 11 .

When it is determined that the voltage generation speed VS2 of the second stack module 12 is slower than the voltage generation speed VS1 of the first stack module 11, the controller 40 moves the flap 55 to the first air supply path. (51) by rotating at a certain rotation angle, the cross-sectional area of the passage of the second air supply path 52 is relatively increased, and the air flow rate supplied to the second stack module 12 is increased to increase the flow rate of the second stack module 12. It is possible to match the voltage generation speed (VS2) of the voltage generation speed (VS1) of the first stack module 11 (S13).

Here, the rotation angle of the flap 55 may be set to correspond to a difference between the voltage generation speed VS2 of the second stack module 12 and the voltage generation speed VS1 of the first stack module 11 .

If it is determined in step S12 that the voltage generation speed VS2 of the second stack module 12 is not slower than the voltage generation speed VS1 of the first stack module 11, the voltage generation speed of the first stack module 11 ( It is determined whether VS1) is slower than the voltage generation speed (VS2) of the second stack module 12 (S14). That is, it is determined whether the air flow rate introduced into the first stack module 11 is smaller than the air flow rate introduced into the second stack module 12 .

When it is determined that the voltage generation speed VS1 of the first stack module 11 is slower than the voltage generation speed VS2 of the second stack module 12, the control unit 40 moves the flap 55 to the second air supply path. (52) by rotating at a certain rotation angle, the cross-sectional area of the passage of the first air supply path 51 is relatively increased, and the air flow rate supplied to the first stack module 11 is increased to increase the flow rate of the first stack module 11. The voltage generation rate (VS1) of the second stack module 12 may match the voltage generation rate (VS2) (S15).

In step S14, if the voltage generation speed VS1 of the first stack module 11 is not slower than the voltage generation speed VS2 of the second stack module 12, the voltage generation speed VS1 of the first stack module 11 ) can determine that the voltage generation speed (VS2) of the second stack module 12 is the same, and the controller 40 places the flap 55 in a neutral position (S16).

8 is a flowchart illustrating a control method of an air distribution device according to another embodiment of the present invention.

The controller 40 monitors the voltage V1 of the first stack module 11 and the voltage V2 of the second stack module 12 (S21).

If the fuel cell system suddenly operates in an idle state, water condensed in the humidifier 23 may flow into the stack modules 11 and 12, which may cause a rapid voltage drop (cell loss) due to flooding. . In this way, when a sudden voltage drop occurs in any one of the first stack module 11 and the second stack module 12, the air flow rate supplied to the stack module is increased to prevent the sudden voltage drop due to flooding. need to be resolved quickly.

The controller 40 determines whether a sudden voltage drop occurs in the first stack module 11 and the second stack module 12 (S22).

When it is determined that a rapid voltage drop has occurred in the second stack module 12, the control unit 40 rotates the flap 55 toward the first air supply path 51 at a predetermined rotational angle, thereby increasing the second air supply path 52. A rapid voltage drop due to flooding in the second stack module 12 can be quickly resolved by increasing the cross-sectional area of the passage and increasing the air flow rate supplied to the second stack module 12 (S23). .

Here, the rotation angle of the flap 55 may be set according to the rapid voltage drop of the second stack module 12 .

If it is determined in step S22 that no rapid voltage drop occurs in the second stack module 12, it is determined whether or not a rapid voltage drop occurs in the first stack module 11 (S24).

When it is determined that a sudden voltage drop occurs in the first stack module 11, the control unit 40 rotates the flap 55 toward the second air supply path 52 at a predetermined rotational angle, so that the first air supply path 51 ), and by increasing the air flow rate supplied to the first stack module 11, it is possible to quickly resolve the rapid voltage drop due to flooding in the first stack module 11 (S25 ).

In step S24, if it is determined that no sudden voltage drop has occurred in the first stack module 11, no sudden voltage drop has occurred in any stack module among the first stack module 11 and the second stack module 12. Since it can be determined that it is, the control unit 40 maintains the flap 55 in a neutral position (S26).

Although the specific embodiments of the present invention have been described above, the present invention is not limited by the embodiments disclosed herein and the accompanying drawings, and may be variously modified by those skilled in the art without departing from the technical spirit of the present invention. .

10: Enclosure
11: first stack module
12: second stack module
15: Manifold block
20: air supply unit
30: hydrogen supply unit
50: air distribution device
51: first air supply path
52: second air supply path
55: flap

Claims (15)

An air distribution device of a fuel cell system that variably adjusts distribution of air flow rates supplied to a first stack module and a second stack module,
a first air supply path for guiding a flow of air supplied to the first stack module;
a second air supply path for guiding a flow of air supplied to the second stack module; and
A flap rotatably installed in the branching portions of the first air supply path and the second air supply path;
The passage cross-sectional area of the first air supply passage and the passage cross-sectional area of the second air supply passage are relatively variable by rotation of the flap,
Air of a fuel cell system in which a manifold block is commonly connected to the first stack module and the second stack module, and the first air supply path and the second air supply path diverge from the air inlet of the manifold block. distribution device. The method of claim 1,
The air distribution device of a fuel cell system in which the first stack module and the second stack module are installed in an enclosure. The method of claim 2,
An air distribution device of a fuel cell system in which the manifold block is installed on one side of the enclosure. The method of claim 1,
The flap is an air distribution device of a fuel cell system formed in a wedge shape with a narrow tip. The method of claim 1,
The air distribution device of a fuel cell system in which the flap is rotatable in both directions by a driving motor. The method of claim 5,
A motor controller is connected to the drive motor, and the motor controller is connected to a control unit. The method of claim 6,
When the air flow rate supplied to any one of the first stack module and the second stack module is relatively small, the controller rotates the flap toward the air supply path of the stack module having a relatively large air flow rate. The air distribution device of the fuel cell system. A control method of an air distribution device of a fuel cell system according to claim 1,
Control of the air distribution device of the fuel cell system for rotating the flap toward the first air supply path at a predetermined angle when the first air flow rate introduced into the first stack module is greater than the second air flow rate introduced into the second stack module method. The method of claim 8,
Control of the air distribution device of the fuel cell system for rotating the flap toward the second air supply path at a predetermined angle when the flow rate of the second air introduced into the second stack module is greater than the flow rate of the first air introduced into the first stack module. method. The method of claim 8,
A method of controlling an air distribution device of a fuel cell system in which the flap is positioned at a neutral position when the second air flow rate introduced into the second stack module is the same as the first air flow rate introduced into the first stack module. A control method of an air distribution device of a fuel cell system according to claim 1,
and rotating the flap toward the first air supply path at a predetermined angle when the voltage generation speed of the second stack module is slower than the voltage generation speed of the first stack module. The method of claim 11,
and rotating the flap toward the second air supply path at a predetermined angle when the voltage generation speed of the first stack module is slower than the voltage generation speed of the second stack module. The method of claim 11,
A method of controlling an air distribution device of a fuel cell system in which the flap is positioned at a neutral position when the voltage generation speed of the first stack module and the voltage generation speed of the second stack module are the same. A control method of an air distribution device of a fuel cell system according to claim 1,
When a sudden voltage drop occurs in any one of the first stack module and the second stack module, the fuel cell system rotates the flap at a predetermined angle toward the air supply path of the stack module where the sudden voltage drop does not occur. Control method of air distribution device. The method of claim 14,
A method for controlling an air distribution device of a fuel cell system, in which the flap is positioned in a neutral position when a sudden voltage drop does not occur in any one of the first stack module and the second stack module.

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