Method of controlling air supply system for fuel cell

Abstract

A method of controlling an air supply system for a fuel cell, in which the air supply system includes a fuel cell stack, an air passage supplying air to an inlet of the fuel cell stack, a gas adsorption unit disposed on the air passage and configured to adsorb oxygen contained in the air introduced into the air passage, the method includes: determining whether to resume a power generation operation of the fuel cell stack; controlling a voltage source to apply a voltage to the gas adsorption unit when the power generation operation of the fuel cell stack is restored; and supplying air to the fuel cell through the air passage in a state in which a voltage is applied to the gas adsorption unit.

Description

[0001] This application is a divisional application of a patent application for invention with the application date of October 14, 2020, application number 202011094518.8, and title "Air Supply System of Fuel Cell and Its Control Method". Technical Field

[0002] The present invention relates to an air supply system for a fuel cell and a control method thereof. Background Art

[0003] The statements in this section only provide background information related to the present disclosure and may not constitute prior art.

[0004] A fuel cell is a power generation device that directly converts the chemical energy generated by fuel oxidation into electrical energy. A fuel cell is basically the same as a chemical battery in that it uses oxidation and reduction reactions, but a fuel cell is different from a chemical battery in that the latter is a closed reaction system in which reactants are continuously supplied and reaction products are continuously removed. In recent years, fuel cells have been put into practical use, and since the reaction product of such a fuel cell is pure water, active research has been conducted to use such a fuel cell as an energy source for environmentally friendly vehicles.

[0005] A fuel cell includes a fuel cell stack that generates electrical energy through a chemical reaction, a gas supply device that supplies air to the air electrode of the fuel cell stack, and a hydrogen supply device that supplies hydrogen to the hydrogen electrode of the fuel cell stack.

[0006] In other words, air containing oxygen is supplied to the air electrode (cathode) of the fuel cell stack, and hydrogen is supplied to the hydrogen electrode (anode) of the fuel cell stack.

[0007] When the operation of the fuel cell stack stops, the supply of air to the fuel cell stack is stopped. In this state, due to the cross-over phenomenon, hydrogen remaining in the hydrogen supply pipeline is introduced into the air electrode, and the introduced hydrogen and the remaining oxygen react on the air electrode. Due to this reaction, a negative pressure is generated in the fuel cell stack, resulting in the problem of introducing external air into the fuel cell stack.

[0008] Figure 1 is a diagram showing a potential curve when oxygen is introduced into the hydrogen electrode in the prior art, and Figure 2 is a graph showing I-V performance curves respectively showing the case where the electrode is corroded and the case where the electrode is not corroded.

[0009] Refer to Figure 1 and Figure 2 , when the fuel cell system stops generating electricity, it is necessary to prevent the supply of air to the fuel cell stack. However, it is difficult to completely prevent air from being introduced into the fuel cell stack.

[0010] Air introduced into the air electrode of a fuel cell stack permeates through the hydrogen electrode. In this case, oxygen in the air is the main cause of electrode corrosion in the fuel cell stack.

[0011] We have found that when the power generation operation of a fuel cell stack resumes after a temporary stop and hydrogen is supplied to the hydrogen electrode, a hydrogen / oxygen interface is formed between region A and region B, thereby forming a high-potential region. Due to the presence of this high-potential region, corrosion is likely to occur on the electrodes of the fuel cell stack.

[0012] When the electrodes in a fuel cell stack are corroded, as can be seen from Figure 2 each unit cell in the fuel cell stack provides a reduced voltage for the same current. That is, the power generation performance of the fuel cell stack is reduced.

[0013] The foregoing is only intended to assist in understanding the background of the present invention and is not intended to represent that the present invention falls within the scope of the prior art known to those skilled in the art. Summary of the Invention

[0014] The present invention provides an air supply system for a fuel cell, which can suppress or prevent oxygen from being introduced into the fuel cell stack when the fuel cell stack stops generating power.

[0015] In one form of the present invention, an air supply system for a fuel cell may include: a fuel cell stack in which a plurality of unit cells are stacked and generate electricity through a chemical reaction; an air passage that supplies introduced air containing oxygen to an inlet of the fuel cell stack and transfers the air discharged from an outlet of the fuel cell stack to the outside of the air supply system; and a gas adsorption unit that is arranged on the air passage, near the outlet of the fuel cell stack, and adsorbs oxygen contained in the air introduced into the air passage.

[0016] The gas adsorption unit may include diatomaceous earth powder containing a metal and a catalyst, such that oxygen in the air flowing through the air passage is adsorbed in the gas adsorption unit.

[0017] The system may further include: a voltage source configured to apply a voltage to the gas adsorption unit to cause the oxygen adsorbed in the gas adsorption unit to react with fuel; and a power supply controller configured to control the voltage source to apply or not apply a voltage to the gas adsorption unit based on the operating state of the fuel cell stack.

[0018] The voltage source may be a part of a plurality of unit cells included in the fuel cell stack.

[0019] The system may further include: a switch disposed between the voltage source and the gas adsorption unit. The power controller is configured to control the switch to turn on when the power generation operation of the fuel cell stack resumes, so that a voltage is applied to the gas adsorption unit through the switch.

[0020] The system may further include: a fuel return passage configured to return the fuel discharged from the outlet of the fuel cell stack to the inlet of the fuel cell stack; a purification passage connecting the fuel return passage and the air passage, wherein the purification passage is connected to the fuel return passage at a position near the outlet of the fuel cell stack; a purification valve disposed on the purification passage and configured to adjust the flow rate of the fuel flowing through the purification passage when the air in the fuel return passage is discharged to the air passage through the purification passage; and a purification controller configured to control the purification valve to open when the power generation operation of the fuel cell stack resumes.

[0021] In another form, the system may further include: a fuel return passage configured to return the fuel discharged from the outlet of the fuel cell stack to the inlet of the fuel cell stack; a purification passage connecting the fuel return passage and the air passage, wherein the purification passage is connected to the fuel return passage at a position near the outlet of the fuel cell stack; and a purification valve disposed on the purification passage and configured to adjust the flow rate of the fuel flowing through the purification passage when the air in the fuel return passage is discharged to the air passage through the purification passage, wherein when the purification valve is controlled to open, the power controller may control the voltage source to apply a voltage to the gas adsorption unit.

[0022] The system may further include: a shut-off valve disposed on the air passage, near the outlet of the fuel cell stack and downstream of the gas adsorption unit, wherein the shut-off valve is configured to prevent air from flowing through the air passage when the power generation operation of the fuel cell stack stops.

[0023] In another form of the present invention, a method for controlling an air supply system for a fuel cell includes: determining whether the power generation operation of the fuel cell stack resumes; when the power generation operation of the fuel cell stack resumes, controlling the voltage source to apply a voltage to the gas adsorption unit; and supplying air to the fuel cell stack through the air passage in a state where a voltage is applied to the gas adsorption unit.

[0024] The method may further include: after supplying air to the fuel cell stack, purifying the fuel return passage by discharging the fuel in the fuel return passage to the air passage, wherein the fuel discharged from the outlet of the fuel cell stack returns to the inlet of the fuel cell stack through the fuel return passage.

[0025] The method may further include: after purifying the fuel return passage, stopping applying a voltage from the voltage source to the gas adsorption unit.

[0026] The method may further include: determining whether the power generation operation of the fuel cell stack has stopped before determining whether to resume the power generation operation of the fuel cell stack; and when the power generation operation of the fuel cell stack stops, stopping applying voltage from the voltage source to the gas adsorption unit.

[0027] In the step of controlling the application of voltage to the gas adsorption unit, a part of the plurality of unit cells included in the fuel cell stack may be connected to the gas adsorption unit.

[0028] When the power generation operation of the fuel cell stack stops, the system and method of the present invention can prevent oxygen from being introduced into the fuel cell stack. Therefore, the system and method can prevent corrosion of the fuel cell electrodes when resuming the power generation operation of the fuel cell stack, thereby improving the durability of the fuel cell stack.

[0029] In addition, the system and method of the present invention are configured such that when resuming the power generation operation of the fuel cell stack, hydrogen discharged from the fuel return channel can react with oxygen. Therefore, when resuming the power generation operation of the fuel cell stack, the concentration of hydrogen discharged into the external air can be reduced.

[0030] Based on the description provided herein, other application fields will become apparent. It should be understood that the description and specific examples are for illustrative purposes only and are not intended to limit the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] For a better understanding of the present invention, various forms of the present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0032] Figure 1 is a diagram showing a potential curve when oxygen is introduced into the fuel electrode in the prior art;

[0033] Figure 2 is a graph showing I-V performance curves respectively showing the case where the electrode is corroded and the case where the electrode is not corroded;

[0034] Figure 3 is a schematic diagram showing the structure of a fuel cell air supply system according to one form of the present invention;

[0035] Figure 4 is a view showing the overall structure of a gas adsorption unit used in one form of the present invention;

[0036] Figure 5 is a flowchart showing a method for controlling a fuel cell air supply system according to one form of the present invention; and

[0037] Figure 6It is a graph showing the performance difference between a fuel cell of a fuel cell air supply system applying one form of the present invention and a typical fuel cell of a comparative example.

[0038] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present invention in any way. Detailed Description

[0039] The following description is merely exemplary in nature and is not intended to limit the present invention, its application, or uses. It should be understood that in all the accompanying drawings, corresponding reference numerals denote the same or corresponding components and features.

[0040] A specific structural or functional description of a form of the present invention is provided for illustrative purposes only. The present invention can be implemented in various forms and should not be construed as being limited to the forms described in the present invention.

[0041] According to the concept of the present invention, it can have various forms, and only some forms will be shown in the accompanying drawings and described in detail below. Therefore, the present invention should be construed as covering not only the specific forms but also all modifications, equivalents, and alternatives falling within the concept and technical spirit of the present invention.

[0042] The terms "first", "second", etc. used in the specification may be used to distinguish one element from another element. Unless otherwise specified, the order or priority of these elements is not limited by these terms. Therefore, without departing from the scope of the present invention, for the purpose of merely distinguishing one element from another element, the first element of one form may be referred to as the second element of another form, and similarly, the second element of one form may be referred to as the first element of another form.

[0043] It should be understood that when an element is referred to as "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be an intermediate element between them. Conversely, it should be understood that when an element is referred to as "directly coupled" or "directly connected" to another element, there is no intermediate element. Other expressions used herein to describe the relationship between elements, such as "between", "directly between", "adjacent", or "directly adjacent", should be interpreted in the same manner as described above.

[0044] The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the present invention. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It is further to be understood that when the terms "comprises", "comprising", or "has" are used in this specification, they specify the presence of stated features, regions, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and / or combinations thereof.

[0045] In addition, all terms including technical or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present invention. These terms should not be interpreted as having an ideal or overly formal meaning unless expressly defined in this application.

[0046] Hereinafter, exemplary forms of the present invention will be described with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

[0047] Figure 3 is a schematic diagram showing the configuration of a fuel cell air supply system in one form of the present invention, and Figure 4 is a schematic diagram showing the configuration of a gas adsorption unit used in one form of the present invention.

[0048] Referring to Figure 3 and Figure 4 , the fuel cell air supply system includes: a fuel cell stack 10 including a plurality of unit cells stacked on one another and generating electric power through a chemical reaction; an air passage 20 configured to supply oxygen-containing air to an inlet 11 of the fuel cell stack and discharge the air discharged from an outlet 12 of the fuel cell stack 10 to the outside; and a gas adsorption unit 30 disposed on the air passage 20, near the outlet 12 of the fuel cell stack 10, and configured to absorb oxygen in the air introduced into the air passage 20.

[0049] The fuel cell stack 10 receives hydrogen used as fuel and oxygen-containing air and generates electric power through a chemical reaction at an anode (also referred to as a hydrogen electrode or a fuel electrode) and a cathode (also referred to as an oxygen electrode or an air electrode). In the fuel cell stack 10, hydrogen and oxygen react with each other, thereby producing water as a by-product.

[0050] The fuel cell stack 10 is a stack of a plurality of unit cells. Fuel (hydrogen) and air (oxygen) are introduced into each unit cell to generate electricity. The unit cells are connected in series so that the fuel cell stack 10 can output a rated voltage.

[0051] The air passage 20 is used to supply external air to the fuel cell stack 10 and discharge the used air discharged from the fuel cell stack 10 to the outside. A blower or compressor 21 is located at the input port of the air passage 20.

[0052] When the fuel cell stack 10 generates electric power, the blower or compressor 21 operates so that air can be introduced into the fuel cell stack 10 through the air passage 20, and then the used air is discharged from the fuel cell stack 10 to the outside through the air passage 20.

[0053] However, when the power generation operation of the fuel cell stack 10 stops, the introduction of air into the air passage 20 is stopped. At this time, the air flows back into the fuel cell stack 10 through the outlet 12.

[0054] A humidifier 22 for humidifying the air to be introduced into the fuel cell stack 10 is located near the input port of the air passage 20. The humidifier 22 is connected to the output port of the air passage 20, and the air passage 20 is connected to the outlet 12 of the fuel cell stack 10. The humidifier 22 can be used to transfer the moisture contained in the air discharged from the output port of the air passage 20 to the inlet 11 of the fuel cell stack 10.

[0055] The gas adsorption unit 30 is provided near the outlet of the air passage 20. In other words, the gas adsorption unit 30 is provided on the air passage 20 and is located near the outlet 12 of the fuel cell stack 10.

[0056] In a state where the power generation operation of the fuel cell stack 10 is not performed, the gas adsorption unit 30 adsorbs and removes the oxygen contained in the air discharged from the output port of the air passage 20.

[0057] Therefore, when the power generation operation of the fuel cell stack 10 stops, the introduction of oxygen into the fuel cell stack 10 is blocked or prevented, and since the corrosion of the electrodes is prevented when the power generation operation of the fuel cell stack 10 is restored, the durability of the fuel cell stack 10 can be improved.

[0058] In one form, the gas adsorption unit 30 includes diatomaceous earth powder containing a metal and a catalyst. The gas adsorption unit 30 adsorbs the oxygen contained in the air flowing through the air passage 20.

[0059] The diatomaceous earth powder may include iron powder, promoter (catalyst) particles, and a filler. The gas adsorption unit 30 is made of coated diatomaceous earth nanoparticles. The gas adsorption unit 30 adsorbs the oxygen contained in the air flowing through the air passage 20.

[0060] When a voltage is applied to the gas adsorption unit 30, hydrogen and oxygen react with each other to produce water. The hydrogen in the air flowing through the air passage 20 reacts with the oxygen adsorbed on the gas adsorption unit 30. Therefore, the amount of hydrogen discharged through the air passage 20 can be reduced.

[0061] The air supply system further includes: a voltage source 40 that applies a voltage to the gas adsorption unit 30 so that the oxygen adsorbed on the gas adsorption unit 30 can react with the fuel (i.e., hydrogen); and a power supply controller 80 that controls the application of voltage from the voltage source to the gas adsorption unit 30 based on the operating state of the fuel cell stack 10.

[0062] In another form, when the power generation operation of the fuel cell stack 10 is resumed, the power supply controller 80 controls the voltage source 40 to apply a voltage to the gas adsorption unit 30. Therefore, the oxygen adsorbed in the gas adsorption unit 30 reacts with the hydrogen discharged from the fuel return passage into the air passage 20, thereby removing hydrogen from the air for discharge to the outside.

[0063] In some forms, when the power generation operation of the fuel cell stack 10 stops, the power supply controller 80 controls the voltage source 40 to stop applying a voltage to the gas adsorption unit 30. Therefore, oxygen can be adsorbed in the gas adsorption unit 30.

[0064] In some forms, it is possible to stop applying voltage from the voltage source 40 to the gas adsorption unit 30 while continuing the power generation operation of the fuel cell stack. In a state where the power generation operation of the fuel cell stack stops, the voltage source 40 is controlled to apply a voltage to the gas adsorption unit 30 for a predetermined period of time to remove the oxygen adsorbed in the gas adsorption device 30.

[0065] The voltage source 40 can be implemented by a part of the plurality of unit cells included in the fuel cell stack 10. In other words, the voltage source 40 can be implemented by a discrete device (e.g., a separate battery) or a part of the plurality of unit cells included in the fuel cell stack 10.

[0066] The air supply system further includes a switch 41 provided between the voltage source 40 and the gas adsorption unit 30. The power supply controller 80 controls the switch 41 to be turned on so that when the power generation operation of the fuel cell stack 10 stops and then resumes, a voltage can be applied to the gas adsorption unit 30 through the switch.

[0067] The power supply controller 80 can control the switch 41 to be turned on so that the voltage source 40 and the gas adsorption unit 30 are connected to each other or control the switch 41 to be turned off so that the voltage source 40 and the gas adsorption unit 30 are disconnected from each other.

[0068] The air supply system further includes a fuel return passage 50 through which fuel discharged from the outlet of the fuel cell stack 10 returns to the inlet of the fuel cell stack 10.

[0069] In another form, the system may further include a purge valve 61 disposed on a purge passage 60 connecting the fuel return passage 50 and the air passage 20. In some forms, the purge passage 60 is connected to the fuel return passage 50 at a location near the outlet of the fuel cell stack 10, and the purge valve 61 controls the flow rate of fuel discharged from the fuel return passage 50 to the air passage 20 through the purge passage 60. In one form, the system may further include a purge controller 70 that controls the purge valve to open when the power generation operation of the fuel cell stack 10 stops and then resumes.

[0070] The fuel return passage 50 is a flow path along which hydrogen gas mixed with impurities such as moisture and nitrogen flows. The fuel return passage 50 is periodically purged so that hydrogen gas with impurities in the fuel return passage 50 can be removed periodically.

[0071] The purge controller 70 controls the purge valve to open or close. In this way, the fuel return passage 50 can be purged. The purge controller 70 estimates the hydrogen concentration in the air within the fuel return passage 50 and controls the purge valve to open when the estimated hydrogen concentration is lower than a predetermined lower limit value to purge the fuel return passage 50.

[0072] During the power generation operation stop of the fuel cell stack 10, hydrogen gas is not supplied to the fuel electrode. In this state, a crossover phenomenon occurs between the fuel electrode and the air electrode, so the impurity concentration increases.

[0073] For this reason, when the power generation operation of the fuel cell stack 10 stops and then resumes, the purge controller 70 controls the purge valve to open, so that the fuel return passage 50 can be purged.

[0074] When controlling the purge valve to open, the power controller 80 controls the voltage source 40 to apply a voltage to the gas adsorption unit 30.

[0075] The purge controller 70 controls the purge valve to open so that the fuel return passage 50 can be purged not only when the power generation operation of the fuel cell stack 10 stops and then resumes, but also when the power generation operation of the fuel cell stack 10 continues.

[0076] When the purge controller 70 controls the purge valve to open, the power controller 80 controls the voltage source 40 to apply a voltage to the gas adsorption unit 30 so that hydrogen gas discharged from the fuel return passage 50 to the air passage 20 can react with oxygen adsorbed on the gas adsorption unit 30.

[0077] The system may further include shut-off valves 23 and 24, which are arranged on the air passage 20, downstream of the gas adsorption unit 30, and configured to prevent air from flowing through the air passage 20 when the power generation operation of the fuel cell stack 10 stops.

[0078] In one form, the shut-off valves 23 and 24 are arranged on the air passage 20 and are near the outlet 12 of the fuel cell stack 10. The shut-off valves 23 and 24 prevent air from flowing through the air passage during a period when the power generation operation of the fuel cell stack 10 stops.

[0079] However, even in a state where the shut-off valves 23 and 24 are closed, if the state where the power generation operation of the fuel cell stack 10 stops continues for a long time, air may also be introduced into the air passage 20. The gas adsorption unit 30 arranged on the air passage 20 is near the outlet 12 of the fuel cell stack 10 and is downstream of the shut-off valves 23 and 24.

[0080] In addition, other shut-off valves 23 and 24 may be arranged on the air passage 20 and are near the inlet 11 of the fuel cell stack 10.

[0081] In one form of the present invention, the purification controller 70 and the power supply controller 80 may be implemented by: a non-volatile memory (not shown), which is configured to store data associated with an algorithm for controlling the operation of various components of the vehicle or data associated with software instructions for executing the algorithm; a processor (not shown), which is configured to perform the operations described below using the data stored in the non-volatile memory. The memory and the processor may be implemented by discrete chips respectively. The memory and the processor may be implemented by an integrated chip. The processor may be implemented by a processor array.

[0082] Figure 5 is a flowchart showing a method of controlling such a fuel cell air supply system according to one form of the present invention.

[0083] Referring to Figure 5 , a method of controlling a fuel cell air supply system includes: step S300 of determining whether to resume the power generation operation of the fuel cell stack 10; step S400 of applying a voltage to the gas adsorption unit 30 when it is determined that the power generation operation of the fuel cell stack 10 resumes; and step S500 of supplying air to the air passage 20 connected to the fuel cell stack 10 in a state where a voltage is applied to the gas adsorption unit 30.

[0084] Before step S300, the method may further include: step S100 of determining whether the power generation operation of the fuel cell stack 10 stops; and step S200 of stopping applying a voltage to the gas adsorption unit 30 when it is determined that the power generation operation of the fuel cell stack 10 stops.

[0085] When it is determined that the power generation operation of the fuel cell stack 10 stops, the switch 41 is turned off so that a voltage cannot be applied to the gas adsorption unit 30. In this case, the oxygen contained in the air flowing through the air passage 20 can be adsorbed on the gas adsorption unit 30.

[0086] When the power generation operation of the fuel cell stack 10 is resumed after the stop, a voltage can be applied to the gas adsorption unit 30 from the voltage source 40.

[0087] In step S500, air is supplied to the air passage 20 and a voltage is continuously applied to the gas adsorption unit 30, whereby the oxygen adsorbed on the gas adsorption unit 30 can be removed.

[0088] After the step S500 of supplying air, the method may further include step S600: purifying the fuel return passage 50 through which the fuel discharged from the outlet of the fuel cell stack 10 returns to the inlet of the fuel cell stack 10, so that the fuel in the fuel return passage 50 is discharged into the air passage 20.

[0089] While air is being supplied to the air passage 20, the fuel in the fuel return passage 50 is discharged into the air passage 20. Therefore, the fuel in the fuel return passage 50 is diluted by the air before being discharged to the outside.

[0090] In step S500 of supplying air, since the gas adsorption unit 30 is in a state where a voltage is applied, the discharged fuel (hydrogen) reacts with the oxygen adsorbed on the gas adsorption unit 30. Therefore, the concentration of hydrogen is reduced before the air is discharged to the outside.

[0091] After step S600 in which the fuel is discharged into the air passage 20, when the fuel is completely discharged from the fuel return passage, the method may further include step S700: stopping the application of voltage from the voltage source 40 to the gas adsorption unit 30.

[0092] In other words, when the purification is completed and thus there is no hydrogen in the air passage 20, the switch 41 is turned off, so that the application of voltage from the voltage source 40 to the gas adsorption unit 30 can be stopped. Through this process, power consumption can be reduced.

[0093] In addition, when it is desired to stop the power generation operation of the fuel cell stack 10, the switch 41 is turned on so that the application of voltage from the voltage source 40 to the gas adsorption unit 30 is started again. In this way, the oxygen adsorbed on the gas adsorption unit 30 can be removed before the power generation operation of the fuel cell stack 10 stops.

[0094] In step S400 of applying a voltage from voltage source 40 to gas adsorption unit 30, a part of the plurality of unit cells included in fuel cell stack 10 is connected to gas adsorption unit 30. In this case, the electric power generated by fuel cell stack 10 is used to apply a voltage to gas adsorption unit 30 without using an additional power source.

[0095] Figure 6 is a graph showing the performance difference between a fuel cell of a fuel cell air supply system to which one form of the present invention is applied and a typical fuel cell of a comparative example.

[0096] In this graph, each curve represents the average voltage of each unit cell of the plurality of unit cells in the corresponding fuel cell when it is assumed that each fuel cell supplies the same current.

[0097] Referring to Figure 6 , in the case of using a fuel cell air supply system of one form of the present invention to suppress or prevent electrode corrosion of a fuel cell, the performance degradation of the fuel cell of the present invention is slower than that of a typical fuel cell of a comparative example.

[0098] Although only exemplary forms have been described, those skilled in the art will understand that various modifications and changes can be made thereto without departing from the scope and spirit of the present invention.

Claims

1. A method for controlling an air supply system for a fuel cell, wherein, The air supply system includes a fuel cell stack, an air passage for supplying air to an inlet of the fuel cell stack, and a gas adsorption unit provided on the air passage and configured to adsorb oxygen contained in the air introduced into the air passage. The method includes: Determining whether to resume the power generation operation of the fuel cell stack; When the power generation operation of the fuel cell stack is resumed, controlling a voltage source to apply a voltage to the gas adsorption unit; and Supplying air to the fuel cell stack through the air passage in a state where a voltage is applied to the gas adsorption unit.

2. The method according to claim 1 further comprises: After supplying air to the fuel cell stack, purifying the fuel return passage by discharging fuel in the fuel return passage into the air passage, wherein the fuel discharged from an outlet of the fuel cell stack returns to the inlet of the fuel cell stack through the fuel return passage.

3. The method according to claim 2 further comprises: After purifying the fuel return passage, stopping applying a voltage from the voltage source to the gas adsorption unit.

4. The method according to claim 1, further comprising: Before determining whether to resume the power generation operation of the fuel cell stack, determining whether the power generation operation of the fuel cell stack has stopped; And When the power generation operation of the fuel cell stack stops, preventing a voltage from being applied to the gas adsorption unit.

5. The method according to claim 1, wherein In the step of controlling the voltage source to apply a voltage to the gas adsorption unit, connecting a part of a plurality of unit cells included in the fuel cell stack to the gas adsorption unit.

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