Fuel cell system for product management

Abstract

The present invention relates to a fuel cell system for product management. According to one embodiment, a fuel cell system for product management can be provided, the system comprising: a first fuel tank in which cathode fuel is stored; a second fuel tank in which anode fuel is stored; a fuel cell stack receiving, from the first fuel tank and the second fuel tank, the cathode fuel and the anode fuel, which are reaction gases, thereby generating electric energy; a purge valve for discharging, from the fuel cell stack to the outside, a product resulting from the reaction of the cathode fuel and the anode fuel; and a control unit for controlling opening and closing operations of the purge valve on the basis of the concentration or internal humidity of the reaction gases in the fuel cell stack.

Description

Fuel cell system for product management

[0001] The present invention relates to a fuel cell system for product management.

[0002] Fuel cells are power generation devices that directly convert the chemical energy of hydrogen and oxygen into electrical energy. They are considered an efficient and environmentally friendly alternative to conventional internal combustion engines and chemical batteries. Unlike conventional batteries, fuel cells can continuously produce electricity simply by supplying hydrogen and oxygen, and their energy generation efficiency is higher.

[0003] These fuel cells generally produce electricity by directly reacting hydrogen and oxygen, and when using a reformer, they are a power generation system that can directly convert the chemical reaction energy of hydrogen contained in hydrocarbon-based substances such as LNG (liquefied natural gas), LPG (liquefied petroleum gas), methanol (CH3OH), ethanol (C2H5OH), and gasoline into electrical energy. At the cathode, an electrochemical reaction occurs where a reduction reaction of oxygen, which is an oxidizing agent, occurs, and at the anode, an oxidation reaction of hydrogen, which is a fuel, occurs, generating electricity, heat, water, etc.

[0004] Meanwhile, in the case of conventional fuel cell systems, it is known that hydrogen ions and oxygen meet at the cathode of the fuel cell stack to generate water, but due to back diffusion caused by the difference in water concentration or pressure between the cathode and the anode, a significant amount of water generated at the cathode moves to the anode through the electrolyte membrane.

[0005] That is, not only the cathode but also the anode side continues to accumulate water that has flowed from the cathode without being removed to a significant extent, and accordingly, a separate discharge valve must be installed in the fuel cell stack to periodically discharge the water.

[0006] However, the water discharge method in these conventional fuel cell systems has the following problems.

[0007] When the reaction gas is discharged through the operation of a hydrogen and oxygen purge valve separately provided in the fuel cell stack of the fuel cell system, water may be discharged together with the reaction gas, but as a one-way gas flow of the reaction gas is generated, the vaporized water or liquefied water may flow along the one-way gas flow and accumulate in a predetermined area within the fuel cell stack.

[0008] In addition, when the reaction gas is discharged, new reaction gas is introduced into the fuel cell stack through the operation of separately provided hydrogen and oxygen supply valves to replenish the amount of reaction gas in the fuel cell stack, and accordingly, the newly introduced reaction gas also flows along a one-way gas flow. Here, since the newly introduced reaction gas is reaction gas with almost no moisture, the area in the fuel cell stack into which the reaction gas is introduced can be in a dry state.

[0009] In addition, when the fuel cell stack rotates through the operation of a separately provided rotor, vaporized or liquefied water in the internal space of the fuel cell stack can be moved to a predetermined area within the fuel cell stack by centrifugal force.

[0010] In other words, in the fuel cell system as described above, water is distributed unevenly in the internal space of the fuel cell stack, and more specifically, the area where the reaction gas flows into the fuel cell stack may experience a phenomenon in which the cell performance is reduced due to insufficient moisture (drying), and the area where the reaction gas is discharged from the fuel cell stack or the area far from the rotation axis may experience a phenomenon in which an excessive amount of condensate blocks the microscopic channels of the anode and cathode, thereby blocking the flow path of the reaction gas (flooding).

[0011] Accordingly, various problems may arise due to reduced performance and output limitations of the fuel cell, and if continuous drying and flooding occur, the durability of the fuel cell catalyst may be reduced due to deterioration, and the problem of increased replacement costs may arise due to the deterioration of the durability of the fuel cell.

[0012] A fuel cell system for product management according to one embodiment of the present invention is proposed to solve the above problems, and by uniformly distributing products generated in the fuel cell system within the fuel cell stack, drying and flooding within the fuel cell stack can be prevented, and the stability and durability of the fuel cell system can be improved.

[0013] According to one embodiment, a fuel cell system for product management may be provided, including: a first fuel tank storing cathode fuel; a second fuel tank storing anode fuel; a fuel cell stack receiving cathode fuel and anode fuel, which are reaction gases, from the first fuel tank and the second fuel tank to generate electrical energy; a purge valve discharging a product resulting from the reaction of the cathode fuel and the anode fuel to the outside from the fuel cell stack; and a control unit controlling an opening and closing operation of the purge valve based on a concentration or internal humidity of a reaction gas within the fuel cell stack. The control unit may control the opening and closing operation of the purge valve to form a first flow, which is a gas flow in which the cathode fuel and the anode fuel flow from one side to the other side within the fuel cell stack, or a second flow, which is a gas flow in which the cathode fuel and the anode fuel flow from the other side to one side within the fuel cell stack.

[0014] In addition, a fuel cell system for product management may be provided, wherein the purge valve includes a first purge valve that induces cathode fuel and anode fuel to flow in a first flow, which is a gas flow from one side to the other side inside the fuel cell stack; and a second purge valve that induces cathode fuel and anode fuel to flow in a second flow, which is a gas flow from the other side to the one side inside the fuel cell stack.

[0015] A concentration calculation unit for calculating the concentration of a reaction gas within the fuel cell stack may be provided.

[0016] The above control unit can open the first purge valve when the concentration of the reaction gas calculated from the concentration calculation unit is less than the reference concentration value.

[0017] The concentration calculation unit may further include at least one of a concentration sensor unit that measures the partial pressure of the reaction gas within the fuel cell stack and then calculates a concentration value of the reaction gas based on the partial pressure and provides the concentration value of the reaction gas to the control unit; a current integration calculation unit that calculates a stack current integration value by integrating current output from the fuel cell stack and calculates a concentration value of the reaction gas based on the stack current integration value; a voltage deviation calculation unit that calculates a voltage deviation, which is a difference between an average output voltage of the fuel cell stack and a minimum output voltage among the output voltages of the fuel cell stack, and calculates a concentration value of the reaction gas based on the voltage deviation; and a humidity calculation unit that calculates an internal humidity within the fuel cell stack and calculates a concentration value of the reaction gas based on the voltage deviation.

[0018] In addition, a fuel cell system for product management may be provided in which the control unit receives the concentration of the reaction gas calculated from the concentration sensor unit, and outputs an opening signal to provide the signal to a purge valve when the concentration of the calculated reaction gas is lower than a preset reference concentration value.

[0019] In addition, a fuel cell system for product management may be provided in which the control unit outputs a first opening signal for inducing the first flow within the fuel cell stack or a second opening signal for inducing the second flow within the fuel cell stack.

[0020] In addition, a fuel cell system for product management may be provided in which the first purge valve receives a first opening signal from the control unit and performs an opening operation to induce the product to flow in the same direction as the first flow for a preset reference time and discharge it to the outside, and the second purge valve receives a second opening signal from the control unit and performs an opening operation to induce the product to flow in the same direction as the second flow for a preset reference time and discharge it to the outside.

[0021] In addition, a fuel cell system for product management may be provided, wherein the fuel cell stack further includes a humidity calculation unit that calculates the internal humidity within the fuel cell stack and provides the calculated humidity to the control unit.

[0022] The above humidity calculation unit can calculate the internal humidity of one side of the fuel cell stack.

[0023] In addition, the control unit may be provided with a fuel cell system for product management that provides an opening signal to the second purge valve when the internal humidity of one side of the stack internal area calculated by the humidity calculation unit is less than the reference humidity value.

[0024] According to another embodiment, a method for operating a fuel cell system for product management is provided, the method comprising: receiving a concentration of a reaction gas within the fuel cell stack; opening a first purge valve when the concentration of the reaction gas is less than a preset reference concentration value to form a first flow, which is a gas flow of cathode fuel and anode fuel from one side to the other side within the fuel cell stack; and opening a second purge valve when the humidity of one side within the fuel cell stack is less than the reference humidity value to form a second flow, which is a gas flow of cathode fuel and anode fuel from the other side to the one side within the fuel cell stack.

[0025] According to one embodiment, a computer program stored on a recording medium may be provided to execute a method of operating a fuel cell system for product management using a computing device.

[0026] A fuel cell system for product management according to one embodiment of the present invention has the effect of preventing drying and flooding inside a fuel cell stack and improving the stability and durability of the fuel cell system by uniformly distributing products generated in the fuel cell system within the fuel cell stack.

[0027] FIG. 1 is a drawing schematically illustrating a fuel cell system for product management according to one embodiment of the present invention.

[0028] FIG. 2 is a drawing for explaining the flow of products flowing through a rotating body in a fuel cell system for product management according to one embodiment of the present invention.

[0029] FIG. 3 is a drawing for explaining the non-uniform distribution of products within a cathode in a fuel cell system for product management according to one embodiment of the present invention.

[0030] FIG. 4 is a drawing for explaining the uniform distribution of products in a cathode due to the opening operation of a second purge valve in a fuel cell system for product management according to one embodiment of the present invention.

[0031] FIG. 5 is a flowchart illustrating an operating method of a fuel cell system for product management according to one embodiment of the present invention.

[0032] In order to fully understand the configuration and effect of the present invention, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0033] The present invention is not limited to the embodiments disclosed below, but can be implemented in various forms and subject to various modifications and changes. However, the description of these embodiments is provided to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the present invention of the scope of the invention. In the attached drawings, components are illustrated in enlarged size for convenience of explanation, and the proportions of each component may be exaggerated or reduced.

[0034] The terminology used herein is for the purpose of describing embodiments and is not intended to limit the present invention. In addition, the terms used herein can be interpreted as having the meaning commonly known to those of ordinary skill in the art, unless otherwise defined. In this specification, the singular also includes the plural unless specifically stated in the phrase. As used herein, the words "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components, steps, operations, and / or elements mentioned.

[0035] Meanwhile, the open cathode fuel cell, a type of fuel cell with a lightweight stack, features an open cathode structure without a dedicated coolant path. Air is supplied to the cathode electrode, which is exposed to the air, allowing the stack to cool through the airflow.

[0036] Another type of fuel cell, the closed cathode type fuel cell, is cooled by using dedicated coolant channels provided within the bipolar plates.

[0037] The fuel cell of the present invention can be formed as a closed cathode type fuel cell as well as an open cathode type fuel cell.

[0038] In the present invention, a fuel cell system for product management capable of preventing drying and flooding by including a predetermined purge valve for inducing a change in the flow of fluid within a fuel cell stack, thereby inducing a uniform distribution of products generated within the fuel cell system within the fuel cell stack, is secured.

[0039] FIG. 1 is a drawing schematically illustrating a fuel cell system for product management according to one embodiment of the present invention, and FIG. 2 is a drawing for explaining a flow of products flowing by a rotating body operation in a fuel cell system for product management according to one embodiment of the present invention.

[0040] Referring to FIGS. 1 and 2, a fuel cell system (1) for product management according to one embodiment of the present invention may include a first fuel tank (10) in which cathode fuel is stored; a second fuel tank (20) in which anode fuel is stored; a fuel cell stack (30) that receives cathode fuel and anode fuel, which are reaction gases, from the first fuel tank (10) and the second fuel tank (20) to generate electrical energy; a purge valve (40) that discharges a product resulting from the reaction of the cathode fuel and the anode fuel to the outside from the fuel cell stack (30); a driving unit (50) that provides rotational force; and a rotating body (60) that can be rotated by the rotational force of the driving unit.

[0041] First, the first fuel tank (10) can store cathode fuel, and the cathode fuel can be oxygen (O2).

[0042] Here, oxygen may be supplied to the fuel cell stack (30) described later, either pure or impure (i.e., with a concentration of less than 100%). Furthermore, the oxygen may be compressed and stored in a gaseous state in the first fuel tank (10), or may be stored in a liquid state.

[0043] More specifically, the internal pressure of the first fuel tank (10) may be 700 bar, but is not limited thereto, and a vaporizer may be installed and used when liquid oxygen is used.

[0044] In addition, the fuel cell system (1) for product management may include a cathode fuel supply line (11) that can supply oxygen by connecting the first fuel tank (10) and the fuel cell stack (30), and a cathode fuel supply valve (12) that opens the cathode fuel supply line (11).

[0045] The cathode fuel supply line (11) may include at least one cathode fuel pressure reducing valve (13). Specifically, at least one cathode fuel pressure reducing valve (13) may lower the pressure of oxygen in order to stably supply oxygen compressed and stored at high pressure to the fuel cell stack (30).

[0046] The cathode fuel supply valve (12) and the cathode fuel pressure relief valve (13) can be opened using a 12V or 24V battery, but are not limited thereto. In addition, when using liquid oxygen, a separate vaporizer can be installed to ensure a smooth supply of oxygen.

[0047] Here, supplying pure oxygen to the fuel cell stack (30) supplies a higher concentration of oxygen than supplying air containing approximately 21% oxygen. Therefore, the increased oxygen concentration increases the oxygen reduction reaction rate, thereby increasing the electrical energy generation efficiency. Therefore, the use of pure oxygen through the first fuel tank (10) can improve the output of the fuel cell system, making it suitable for aircraft applications requiring lightweight design.

[0048] In addition, since compressed oxygen or vaporized oxygen is supplied to the fuel cell system (1) for product management using a vaporizer (the vaporizer can be deleted when using gaseous oxygen) and a cathode fuel supply valve (12), a separate air supply device and a high-voltage battery, DC-DC converter, etc. used to drive the air supply compressor of the air supply device can be eliminated, making it easy to reduce weight and size. Accordingly, the fuel cell system (1) for product management according to one embodiment of the present invention can be applied and designed not only for aviation but also for a wide range of fields.

[0049] However, it is not limited thereto, and the fuel cell system (1) can supply air to the stack (30) through a conventional air compressor or air blower. That is, the oxidizer supply unit can include one or more of an oxidizer tank, an air blower, and an air compressor.

[0050] In addition, as will be described later, the fuel cell system (1) can supply air inside the stack by rotation of the rotor and stack.

[0051] In one embodiment, the fuel cell system (1) may additionally include one or more of an oxidizer tank, an air blower, and an air compressor, while supplying air inside the stack by rotation of the rotor and the stack.

[0052] The second fuel tank (20) can store anode fuel, and the anode fuel can be hydrogen (H2) in gaseous or liquid form.

[0053] The hydrogen stored in the second fuel tank (20) may be compressed and stored in a gaseous state, or may be stored in a liquid state. Specifically, the internal pressure of the second fuel tank (20) may be 700 bar, but is not limited thereto.

[0054] A fuel cell system (1) for product management may include an anode fuel supply line (21) that can supply hydrogen by connecting a second fuel tank (20) and a fuel cell stack (30), and an anode fuel supply valve (22) that opens the anode fuel supply line (21). The anode fuel supply line (21) may include at least one anode fuel pressure reducing valve (23). Specifically, at least one anode fuel pressure reducing valve (23) may lower the pressure of hydrogen in order to stably supply hydrogen compressed and stored at high pressure to the fuel cell stack (30). The anode fuel supply valve (22) and the anode fuel pressure reducing valve (23) may be opened using a 12 V or 24 V battery, but are not limited thereto.

[0055] When the second fuel tank (20) is opened to initiate hydrogen supply from the second fuel tank (20) in the same manner as the oxygen supply method, at least one anode fuel pressure reducing valve (23) reduces the hydrogen to an appropriate pressure. The hydrogen reduced to an appropriate pressure is supplied to the fuel cell stack (30) at an appropriate pressure through the anode fuel supply valve (22).

[0056] Accordingly, the fuel cell stack (30) supplied with cathode fuel and anode fuel, i.e., reaction gas containing oxygen and hydrogen, is ready for operation with its voltage rising to OCV (Open Circuit Voltage). Accordingly, the electricity generated by the fuel cell stack (30) can supply electricity to components included in the fuel cell system (1) for product management, and the fuel cell system (1) for product management can be capable of operating independently.

[0057] In addition, the fuel cell system (1) for product management according to one embodiment of the present invention has the advantage that the operating time is very fast since the reaction gases, hydrogen and oxygen, are supplied at a constant supply pressure within the fuel cell stack (30) without a device composed of a compressor, an intercooler, a humidifier, etc.

[0058] A fuel cell stack (30) may be a stacked cell composed of a separator, a membrane electrode assembly (MEA), and other auxiliary components. At this time, hydrogen, which is an anode fuel, is supplied to the anode, and oxygen, which is a cathode fuel, is supplied to the cathode.

[0059] The supplied reaction gas reacts on the catalyst in the catalyst layer of the MEA in the fuel cell stack (30). At this time, water is generated as a product of the reaction. Some of the product water is liquefied inside the fuel cell stack (30), and since this liquefied water is the main cause of lowering the performance of the fuel cell stack (30) and deteriorating its durability, the liquefied water must be discharged outside the fuel cell stack (30). Here, the product includes water, but more specifically, may include vaporized water and liquefied water. Hereinafter, vaporized water is expressed as moisture, and liquefied water is expressed as condensate.

[0060] For example, in order to discharge condensate from inside the cell to the outside of the fuel cell stack (30), the conventional technology designed the structure of the cathode separator of the fuel cell stack (30) to facilitate water discharge. The conventional separator added a 3D porous body to facilitate condensate discharge. However, this increases the weight and volume of the stack because it necessarily requires additional components. In addition, this has the disadvantage of increasing the price of the stack because it requires the production of an additional mold to process a complex structure.

[0061] Another conventional technique eliminates the 3D porous structure and curves the channel shape of the separator to alter the flow of the reactant gas, thereby facilitating the discharge of condensate through changes in flow direction and pressure. However, this method also complicates the structure of the separator, increasing processing costs. Another conventional technique adjusts the operating conditions of the fuel cell to remove condensate within the stack. However, this method also complicates the operation, making control difficult, leading to higher costs and reduced durability.

[0062] A fuel cell system (1) for product management according to one embodiment of the present invention may include a purge valve (40) for discharging products, a cathode discharge line (43), an anode discharge line (44), and a reaction gas discharge line (45). The function of the purge valve (40) is to correct the concentration of reaction gases in the anode and cathode, and to remove products.

[0063] In other words, the purge valve (40) can be used to correct the concentration of oxygen and hydrogen in the fuel cell stack (30) and to remove condensate.

[0064] Here, the purge valve (40) includes a first purge valve (41) and a second purge valve (42), and the first purge valve (41) may include a cathode purge valve (41a) and an anode purge valve (41b).

[0065] For example, when the fuel cell stack (30) is operated, the amount of oxygen diffusing through the membrane from the cathode to the anode increases, and since hydrogen is used as fuel, the concentration of hydrogen decreases. As a result, the voltage of the fuel cell stack (30) decreases, and eventually the operation of the fuel cell stack (30) stops. At this time, when the anode purge valve (41b) is opened, pure hydrogen is supplied from the second fuel tank (20) to the fuel cell stack (30), and the concentration of hydrogen in the anode increases again, allowing the fuel cell stack (30) to operate stably.

[0066] Likewise, in the case of the cathode, when the cathode purge valve (41a) is opened, pure oxygen is supplied from the first fuel tank (10) in the fuel cell stack (30) to the fuel cell stack (30), and the concentration of oxygen in the cathode increases again, enabling the fuel cell stack (30) to operate stably.

[0067] Furthermore, the first purge valve (41) and the second purge valve (42) can discharge products (e.g., moisture and condensate) resulting from the reaction of oxygen and hydrogen from the fuel cell stack (30) to the outside. At this time, since the internal pressure of the fuel cell stack (30) is higher than the external pressure, the products are discharged from the fuel cell stack (30) to the outside by opening the first purge valve (41) or the second purge valve (42).

[0068] Meanwhile, a fuel cell system (1) for product management according to one embodiment of the present invention may include a driving unit (50), a rotating body (60), and at least one fuel cell stack (30). Specifically, the fuel cell system (1) for product management may include a driving unit (50) that provides power for the rotational operation of the rotating body (60), a rotating body (60) that rotates with the power provided from the driving unit (50), and at least one fuel cell stack (30) connected to the rotating body (60). At this time, at least one fuel cell stack (30) is connected to the rotating body (60) and its position may be changed by the rotation of the rotating body (60). The number of fuel cell stacks (30) is not particularly limited, and may be configured as a single or multiple fuel cell stacks as needed.

[0069] Accordingly, as the rotor (60) rotates, the fuel cell stack (30) also moves, and the moving fuel cell stack (30) moves the surrounding air in a direction perpendicular to the rotational direction. At this time, if the stack (30) is of the open cathode type, since the air supply channel and the air supply channel for cooling are the same, the moving air is not only supplied to the inside of the separator of the rotating stack (30), but also passes through the cooling fins or cooling structures located inside the separator of the fuel cell stack (30), so that the fuel cell stack (30) can be cooled.

[0070] At this time, when the rotation speed increases, the intensity of the moving air becomes stronger and the cooling amount of the fuel cell stack (30) increases, so that the temperature of the fuel cell stack (30) can be easily and quickly lowered, and conversely, when the rotation speed decreases, the intensity of the moving air becomes weaker, so that the temperature of the stack at the beginning of operation can be quickly raised to the operating temperature.

[0071] That is, the rotation speed can be adjusted to control the optimal operating conditions of the fuel cell system (1) for product management, and this can eliminate the cooling system of the existing fuel cell system.

[0072] Specifically, conventional open cathode type fuel cells use an air blower (or cooling fan) to supply external air to the open cathode path and cool the stack. In contrast, in the present invention, as the rotor (80) and the stack (30) rotate, external air can be supplied into the stack, and the stack can be additionally cooled. Accordingly, conventional pumps, air blowers (cooling fans), 3-way valves, ion removers, cooling water pipes, etc. can be eliminated, and the high-voltage battery for driving the pump and the converter for operating it can be eliminated, thereby enabling miniaturization and weight reduction of the fuel cell system.

[0073] However, it is not limited thereto, and the stack (30) may be formed as a closed cathode type, in which case the stack (30) may be cooled by flowing a cooling fluid into a dedicated coolant passage.

[0074] As illustrated in FIG. 2, the product (e.g., moisture, condensate) is generated inside the fuel cell stack (30) and then can flow to the other side (arrow direction) of the fuel cell stack (30) by centrifugal force caused by the rotation of the rotor (60).

[0075] At this time, the product can be discharged to the outside from the fuel cell stack (30) by opening the first purge valve (41) or the second purge valve (42).

[0076] In addition, the fuel cell system (1) for product management may further be equipped with a control unit (not shown) for controlling the driving unit (50), a temperature sensor unit (not shown), a concentration calculation unit (not shown), and a humidity calculation unit (not shown).

[0077] The control unit can detect the temperature within the fuel cell stack (30) through the temperature sensor unit, and when the detected temperature exceeds a preset reference temperature value, the driving unit (50) can be operated.

[0078] In addition, the control unit can open the first purge valve (41) or the second purge valve (42) based on the concentration of the reaction gas obtained through the concentration calculation unit and the internal humidity obtained through the humidity calculation unit to allow new reaction gas to be supplied to the fuel cell stack (30) while discharging the product to the outside.

[0079] That is, the fuel cell system (1) for product management not only enables cooling of the fuel cell stack (30) by utilizing the rotational motion of the rotor (60), but also eliminates the product by opening the first purge valve (41) or the second purge valve (42), thereby eliminating the use of a separator having a complex structure, thereby reducing the price and weight of the stack and enabling the design of a control program and controller to be simplified.

[0080] In addition, since the cooling of the fuel cell stack (30) through rotation is controlled by the flow of air using centrifugal force, the air supply system and cooling system existing in the existing fuel cell system can be eliminated, which reduces the price and weight of the fuel cell system and allows the system and control program to be designed simply, making it suitable as a fuel cell for use in aviation.

[0081] Referring again to FIGS. 1 and 2, in the fuel cell system (1) for product management according to one embodiment of the present invention, the purge valve (40) may include a first purge valve (41) that induces the cathode fuel and the anode fuel to flow in a first flow, which is a gas flow from one side to the other side inside the fuel cell stack (30), and a second purge valve (42) that induces the cathode fuel and the anode fuel to flow in a second flow, which is a gas flow from the other side to the one side inside the fuel cell stack (30), and the control unit may control the opening and closing operation of the purge valve (40) based on the concentration or internal humidity of the reaction gas in the fuel cell stack (30).

[0082] As described above, the first purge valve (41) may include a cathode purge valve (41a) and an anode purge valve (41b), and when the cathode purge valve (41a) is opened, the cathode fuel in the cathode region of the fuel cell stack (30) flows in the first flow, which is a gas flow from one side to the other side, while the product in the cathode region is discharged to the outside, and when the anode purge valve (41b) is opened, the anode fuel in the anode region of the fuel cell stack (30) flows in the first flow, which is a gas flow from one side to the other side, while the product in the anode region is discharged to the outside.

[0083] That is, when the cathode purge valve (41a) or the anode purge valve (41b) is opened, the reaction gas inside the fuel cell stack (30) is discharged in the first flow, and new cathode fuel and anode fuel are supplied into the fuel cell stack (30), while the product inside the fuel cell stack (30) flows along the first flow and can be discharged to the outside.

[0084] Next, by opening the second purge valve (42), the cathode fuel and anode fuel in the cathode region and anode region of the fuel cell stack (30) flow as a second flow, which is a gas flow from one side to the other, and the products in the cathode region and anode region can be discharged to the outside.

[0085] Furthermore, the discharge direction of the product within the fuel cell stack (30) can be changed by opening the second purge valve (42).

[0086] As previously explained, the rotational motion of the rotor (60) is performed to cool the fuel cell stack (30), and due to the centrifugal force caused by the rotational motion of the rotor (60), the fuel cell stack (30) has an uneven product distribution in which the amount of product is small in one area and large in the other area.

[0087] That is, when the second purge valve (42) is opened, the reaction gas inside the fuel cell stack (30) is discharged as a second flow, and new cathode fuel and anode fuel are supplied into the fuel cell stack (30), and at the same time, the products that are unevenly distributed inside the fuel cell stack (30) can flow along the second flow and be discharged to the outside, thereby redistributing the products inside the fuel cell stack (30).

[0088] Meanwhile, in the fuel cell system (1) for product management according to one embodiment of the present invention, the concentration calculation unit and the humidity calculation unit may be provided in the fuel cell stack (30), and specifically, the control unit may control the opening and closing operation of the purge valve (40) through the concentration calculation unit capable of calculating the concentration of the reaction gas in the fuel cell stack (30) and the humidity calculation unit capable of calculating the internal humidity in the fuel cell stack (30).

[0089] More specifically, the concentration calculation unit may include a concentration sensor unit that measures the partial pressure of the reaction gas within the fuel cell stack (30) and then calculates the concentration value of the reaction gas based on the partial pressure measured, a current integration calculation unit that calculates a stack current integration value by integrating the current output from the fuel cell stack and calculates the concentration value of the reaction gas based on the stack current integration value, a voltage deviation calculation unit that calculates a voltage deviation, which is the difference between the average output voltage of the fuel cell stack and the minimum output voltage among the output voltages of the fuel cell stack, and calculates the concentration value of the reaction gas based on the voltage deviation, and a humidity calculation unit that calculates the internal humidity within the fuel cell stack and calculates the concentration value of the reaction gas based on the voltage deviation.

[0090] That is, the concentration calculation unit can use a conventionally known concentration sensor, current accumulation, voltage deviation, and internal humidity to measure the oxygen concentration in the cathode and the hydrogen concentration in the anode.

[0091] In addition, the humidity calculation unit can calculate the humidity inside the fuel cell stack (30) using a conventionally known method such as AC impedance, current interrupt, current sweep, and humidity sensor.

[0092] The above concentration calculation unit can measure the partial pressure of the reaction gas within the fuel cell stack (30) and then calculate the concentration of the reaction gas based on this and provide it to the control unit.

[0093] For example, the concentration sensor unit may measure the partial pressure of the anode fuel in the anode region and then calculate the concentration of the anode fuel based on this and provide this to the control unit, or may measure the partial pressure of the cathode fuel in the cathode region and then calculate the concentration of the cathode fuel based on this and provide this to the control unit.

[0094] In addition, the humidity calculation unit can calculate the internal humidity within the fuel cell stack (30) and provide it to the control unit.

[0095] The above control unit can be implemented as a processor such as a central processing unit, a graphic processing unit, a microprocessor, or an application-specific semiconductor, and controls the operation of various electronic devices constituting the fuel cell system (1) for product management of the present invention.

[0096] The control unit receives the concentration of the reaction gas calculated from the concentration calculation unit, and if the concentration of the calculated reaction gas is less than a preset reference concentration value, outputs an opening signal and provides it to the purge valve (40), but can output the opening signal so that the first purge valve (41) and the second purge valve (42) sequentially and repeatedly operate.

[0097] Specifically, the control unit receives the concentration of the produced reaction gas, and when the concentration of the produced reaction gas is less than a preset reference concentration value, outputs a first opening signal for inducing the first flow within the fuel cell stack (30) or a second opening signal for inducing the second flow within the fuel cell stack (30) while the operation of the fuel cell stack (30) is maintained, and can sequentially and repeatedly output the first opening signal and the second opening signal.

[0098] Here, the control unit provides the first opening signal to the first purge valve (41) and the second opening signal to the second purge valve (42).

[0099] Accordingly, the first purge valve (41) may receive a first opening signal from the control unit and perform an opening operation to allow the product to flow in the same direction as the first flow for a preset reference time and be discharged to the outside, and the second purge valve (42) may receive a second opening signal from the control unit and perform an opening operation to allow the product to flow in the same direction as the second flow for a preset reference time and be discharged to the outside. Here, the preset reference time may be 5 to 10 minutes.

[0100] For example, the control unit may receive the concentration of the above-described reaction gas, and if the concentration of the above-described reaction gas is less than the preset reference concentration value (once), the control unit may output a first opening signal and provide it to the first purge valve (41), thereby causing the product to be discharged to the outside by the first purge valve (41). Thereafter, the control unit may again receive the concentration of the above-described reaction gas, and if the concentration of the above-described reaction gas is less than the preset reference concentration value (twice), the control unit may output a second opening signal and provide it to the second purge valve (42), thereby causing the product to be discharged to the outside by the second purge valve (42). That is, the control unit may control the first purge valve (41) and the second purge valve (42) to sequentially and repeatedly operate.

[0101] In addition, the control unit receives the concentration of the reaction gas calculated from the concentration sensor unit, and when the concentration of the calculated reaction gas is lower than a preset reference concentration value, outputs an opening signal to provide it to the purge valve (40), and can output the opening signal so that the second purge valve (42) operates after the first purge valve (41) operates continuously multiple times.

[0102] Specifically, the control unit receives the concentration of the produced reaction gas, and when the concentration of the produced reaction gas is less than a preset reference concentration value, the control unit outputs a plurality of first opening signals for inducing the first flow within the fuel cell stack (30) or a second opening signal for inducing the second flow within the fuel cell stack (30) while the operation of the fuel cell stack (30) is maintained, and the plurality of first opening signals and the second opening signals can be sequentially and repeatedly output.

[0103] For example, in the operation process of the fuel cell stack (30), if the control unit receives the concentration of the calculated reaction gas and the concentration of the calculated reaction gas is less than the preset reference concentration value five times, the control unit may output the first opening signal in the first and second times and then provide it to the first purge valve (41) so that the product is discharged to the outside by the first purge valve (41), and then the control unit may output the second opening signal in the third time and then provide it to the second purge valve (42) so that the product is discharged to the outside by the second purge valve (42), and again, the control unit may output the first opening signal in the fourth and fifth times and then provide it to the first purge valve (41). That is, the control unit can control the first purge valve (41) and the second purge valve (42) so that the opening operation in which the first purge valve (41) operates multiple times (twice) and the second purge valve (42) operates single time (once) can be repeatedly performed.

[0104] In addition, when the internal humidity calculated from the humidity calculation unit after the opening operation is completed is less than the reference humidity value, the control unit may re-output the opening signal and provide it to the second purge valve (42). At this time, preferably, the humidity calculation unit may calculate the internal humidity of one side within the fuel cell stack (30) and provide it to the control unit. That is, when one area within the fuel cell stack into which the reaction gas flows in becomes dry, the control unit may open the second purge valve (42) to allow the unevenly distributed products within the fuel cell stack (30) to flow to one side along the second flow. Accordingly, redistribution of the products within the fuel cell stack (30) is achieved, and the humidity of one area within the fuel cell stack into which the reaction gas flows in can be improved.

[0105] However, it is not limited thereto, and the humidity calculation unit can re-output the opening signal and provide it to the second purge valve (42) when the internal humidity of the other side area where the reaction gas is discharged within the fuel cell stack exceeds the preset humidity value.

[0106] In addition, the humidity calculation unit calculates the average humidity based on the humidity of the cathode region and the anode region within the fuel cell stack (30) to calculate the internal humidity and then provides the calculated internal humidity to the control unit, and when the internal humidity exceeds a reference humidity value, for example, 40%, the control unit can output a second opening signal and provide the signal to the second purge valve (42).

[0107] Hereinafter, the redistribution of products within the cathode due to the opening operation of the second purge valve (42) of the fuel cell system (1) for product management will be described.

[0108] FIG. 3 is a drawing for explaining the non-uniform distribution of a product in a cathode in a fuel cell system for product management according to one embodiment of the present invention, and FIG. 4 is a drawing for explaining the uniform distribution of a product in a cathode due to the opening operation of a second purge valve in a fuel cell system for product management according to one embodiment of the present invention.

[0109] Referring to FIG. 3, a fuel cell system (1) for product management may include a cathode fuel supply line (11), a cathode fuel supply valve (12), a cathode within a fuel cell stack (30), a cathode discharge line (43), and a cathode purge valve (41a).

[0110] In order to cool the fuel cell stack (30), a rotating body (60) is operated, and the cathode within the fuel cell stack (30) has an uneven product distribution due to centrifugal force resulting from the rotation of the rotating body (60).

[0111] Specifically, the cathode can be broadly divided into a one-sided region, a middle region, and a second-sided region, and the amount of product increases in the order of the one-sided region, the middle region, and the second-sided region due to centrifugal force. Here, the amount of product refers to the total amount of moisture and condensate.

[0112] At this time, when the cathode purge valve (41a) is opened, the pressure difference between the cathode and the external atmospheric pressure causes oxygen to flow as a first flow, which is a gas flow from one side to the other, and eventually, oxygen and products are discharged together along the cathode discharge line (43).

[0113] That is, the fuel cell system (1) for product management according to the present invention can easily discharge products resulting from the reaction between cathode fuel and anode fuel to the outside while emitting oxygen at high temperature and humidity and having a low concentration.

[0114] However, the products within the cathode may still be unevenly distributed as the hot, humid oxygen and products are exhausted and then supplied with new, cold, dry oxygen.

[0115] Referring to FIG. 4, a fuel cell system (1) for product management includes a cathode fuel supply line (11), a cathode fuel supply valve (12), a cathode in a fuel cell stack (30), a reaction gas discharge line (45), and a second purge valve (42).

[0116] As previously explained, the rotor (60) is operated for cooling according to the operation of the fuel cell stack (30), and the cathode within the fuel cell stack (30) has an uneven product distribution due to the centrifugal force according to the rotational operation of the rotor (60).

[0117] Specifically, the cathode can be broadly divided into a one-sided region, a middle region, and a second-sided region, and the amount of product increases in the order of the one-sided region, the middle region, and the second-sided region due to centrifugal force. Here, the amount of product refers to the total amount of moisture and condensate.

[0118] At this time, when the second purge valve (42) is opened, the pressure difference between the cathode and the external atmospheric pressure causes oxygen to flow as a second flow, which is a gas flow from the other side to one side, and eventually, oxygen and products are discharged together along the cathode fuel supply line (11) and the reaction gas discharge line (45).

[0119] Here, the reaction gas discharge line (45) may be connected to the cathode fuel supply line (11), but is not limited thereto, and may be connected to any configuration in which oxygen flows as a second flow.

[0120] That is, due to the opening of the second purge valve (42), the product within the cathode can be uniformly distributed throughout the entire cathode region, and specifically, the total amount gradient of the product corresponding to one side region, the middle region, and the other side region is minimized, which prevents the drying phenomenon that is likely to occur in the one side region and prevents the flooding phenomenon that is likely to occur in the other side region, thereby achieving an improvement in the stability and durability of the fuel cell system.

[0121] FIG. 5 is a flowchart illustrating an operating method of a fuel cell system for product management according to one embodiment of the present invention.

[0122] A method for operating a fuel cell system for product management according to one embodiment of the present invention (S10) comprises: a first fuel tank storing cathode fuel; a second fuel tank storing anode fuel; a fuel cell stack that receives cathode fuel and anode fuel, which are reaction gases, and generates electrical energy; a purge valve that discharges a product resulting from a reaction of the cathode fuel and the anode fuel to the outside of the fuel cell stack, and includes a first purge valve that induces the cathode fuel and the anode fuel to flow in a first flow, which is a gas flow from one side to the other side within the fuel cell stack, and a second purge valve that induces the cathode fuel and the anode fuel to flow in a second flow, which is a gas flow from the other side to the one side within the fuel cell stack; a driving unit that provides a rotational force; a rotating body that can be rotated by the rotational force of the driving unit; And a control unit for controlling the opening and closing operation of the purge valve based on the concentration or internal humidity of the reaction gas in the fuel cell stack; In the operating method of a fuel cell system for product management, the method may include a step (S100) of receiving the concentration of the reaction gas calculated from a concentration calculation unit provided in the fuel cell stack, a step (S200) of opening the first purge valve by outputting an opening signal when the calculated concentration of the reaction gas is lower than a preset reference concentration value, and a step (S300) of opening the second purge valve by outputting the opening signal when the internal humidity of one side of the fuel cell stack calculated from the humidity calculation unit provided in the fuel cell stack is lower than the reference humidity value.

[0123] Although the fuel cell system for product management according to the embodiments of the present invention has been described in specific embodiments, these are merely examples, and the present invention is not limited thereto, and should be construed to have the broadest scope in accordance with the basic concepts disclosed in this specification. Those skilled in the art may implement embodiments not specified by combining or substituting the disclosed embodiments, but this also does not exceed the scope of the present invention. In addition, those skilled in the art may easily modify or alter the disclosed embodiments based on this specification, and it is clear that such modifications or alterations also fall within the scope of the present invention.

[0124]

[0125] - This research was supported by the Startup Growth Technology Development Project of the Ministry of SMEs and Startups [RS-2024-00437505].

[0126]

[0127] [Explanation of symbols]

[0128] 1: Fuel cell system for product management

[0129] 10: No. 1 fuel tank

[0130] 11: Cathode fuel supply line

[0131] 12: Cathode fuel supply valve

[0132] 13: Cathode fuel pressure relief valve

[0133] 20: Second fuel tank

[0134] 21: Anode fuel supply line

[0135] 22: Anode fuel supply valve

[0136] 23: Anode fuel pressure relief valve

[0137] 30: Fuel cell stack

[0138] 40: Purge valve

[0139] 41: 1st purge valve

[0140] 41a: Cathode purge valve

[0141] 41b: Anode purge valve

[0142] 42: Second purge valve

[0143] 43: Cathode exhaust line

[0144] 44: Anode discharge line

[0145] 45: Reaction gas discharge line

[0146] 50: Drive unit

[0147] 60: Rotor

Claims

1. A first fuel tank storing cathode fuel; A second fuel tank storing anode fuel; A fuel cell stack that generates electrical energy by receiving cathode fuel and anode fuel, which are reaction gases, from the first fuel tank and the second fuel tank; A purge valve that discharges the products resulting from the reaction between the cathode fuel and the anode fuel from the fuel cell stack to the outside; and A fuel cell system for product management, comprising a control unit that controls the opening and closing operation of the purge valve based on the concentration or internal humidity of the reaction gas within the fuel cell stack.

2. In paragraph 1, The above control unit controls the opening and closing operation of the purge valve, A first flow or a gas flow in which cathode fuel and anode fuel flow from one side to the other inside the fuel cell stack A fuel cell system for product management, wherein cathode fuel and anode fuel are capable of forming a second flow, which is a gas flow from one side to the other inside the fuel cell stack.

3. In paragraph 1, The above purge valve, A first purge valve for causing cathode fuel and anode fuel to flow in a first flow, which is a gas flow from one side to the other inside the fuel cell stack; and A fuel cell system for product management, comprising a second purge valve for causing cathode fuel and anode fuel to flow in a second flow, which is a gas flow from one side to the other side within the fuel cell stack.

4. In paragraph 3, The above fuel cell stack, A fuel cell system for product management, comprising a concentration calculation unit for calculating the concentration of a reaction gas within the fuel cell stack.

5. In paragraph 4, The above control unit, A fuel cell system for product management, which opens the first purge valve when the concentration of the reaction gas calculated from the concentration calculation unit is less than the reference concentration value.

6. In paragraph 4, The above concentration calculation unit, A concentration sensor unit that measures the partial pressure of a reaction gas within the fuel cell stack and then calculates the concentration value of the reaction gas based on the partial pressure; A current integration calculation unit that calculates a stack current integration value by integrating the current output from the fuel cell stack and calculates a concentration value of a reaction gas based on the stack current integration value; A voltage deviation calculation unit that calculates a voltage deviation, which is the difference between the average output voltage of the fuel cell stack and the minimum output voltage among the output voltages of the fuel cell stack, and calculates a concentration value of the reaction gas based on the voltage deviation; and A fuel cell system for product management, comprising at least one humidity calculation unit that calculates the internal humidity within the fuel cell stack and calculates the concentration value of a reaction gas based on the internal humidity.

7. In paragraph 3, The above control unit, A fuel cell system for product management, which outputs a first opening signal for inducing the first flow within the fuel cell stack or a second opening signal for inducing the second flow within the fuel cell stack.

8. In paragraph 7, The above first purge valve, When a first opening signal is provided from the above control unit, an opening operation is performed to induce the product to be discharged to the outside for a preset reference time in the same direction as the first flow, The above second purge valve, A fuel cell system for product management, which receives a second opening signal from the above control unit and performs an opening operation to allow the product to flow in the same direction as the second flow for a preset reference time and be discharged to the outside.

9. In paragraph 3, The above fuel cell stack, A fuel cell system for product management, further comprising a humidity calculation unit that calculates the internal humidity within the fuel cell stack and provides the calculated humidity to the control unit.

10. In paragraph 9, The above humidity calculation unit is, A fuel cell system for product management that calculates the internal humidity of one side area inside the fuel cell stack.

11. In paragraph 10, The above control unit, A fuel cell system for product management, which provides an opening signal to the second purge valve when the internal humidity of one side of the stack calculated from the above humidity calculation unit is less than the reference humidity value.

12. In the method of operating a fuel cell system for product management, A step of receiving the concentration of a reaction gas within the fuel cell stack; A step of opening the first purge valve when the concentration of the reaction gas is lower than a preset reference concentration value to form a first flow, which is a gas flow in which cathode fuel and anode fuel flow from one side to the other inside the fuel cell stack; and A method for operating a fuel cell system for product management, comprising the step of opening the second purge valve when the humidity on one side inside the fuel cell stack is lower than the reference humidity value, thereby forming a second flow, which is a gas flow in which cathode fuel and anode fuel flow from the other side to one side inside the fuel cell stack.

13. A computer program stored on a recording medium to execute the method of Article 12 using a computing device.

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