KR20230156547A - Fuel cell system and thermal management method of the same - Google Patents

Abstract

According to embodiments disclosed in this document, a fuel cell system includes: a fuel cell stack; a first cooling line through which first coolant circulates through the fuel cell stack; a first radiator disposed on the first cooling line and cooling the first coolant; a cooling unit in which a plurality of cooling fans are arranged in a plurality of lines and is set to blow outside air to the first radiator; and a control unit connected to the cooling unit and controlling the rotation speed of the plurality of cooling fans based on the coolant temperature at the inlet of the fuel cell stack.

Description

Fuel cell system and its thermal management method {FUEL CELL SYSTEM AND THERMAL MANAGEMENT METHOD OF THE SAME}

Embodiments disclosed in this document relate to a fuel cell system and its thermal management method.

A fuel cell system can generate electrical energy using a fuel cell stack. For example, if hydrogen is used as a fuel for a fuel cell stack, it can be an alternative to solving global environmental problems, so continuous research and development is being conducted on fuel cell systems. The fuel cell system consists of a fuel cell stack that generates electrical energy, a fuel supply device that supplies fuel (hydrogen) to the fuel cell stack, an air supply device that supplies oxygen from the air, an oxidizing agent necessary for electrochemical reactions, to the fuel cell stack, and fuel. It may include a thermal management system (TMS) that removes reaction heat from the cell stack to the outside of the system, controls the operating temperature of the fuel cell stack, and performs a water management function.

The thermal management system is a type of cooling device that maintains an appropriate temperature (e.g., 60 to 70°C) by circulating antifreeze, which acts as coolant, into the fuel cell stack. It consists of a TMS line through which coolant circulates, a reservoir where coolant is stored, It may include a pump that circulates coolant, an ion filter that removes ions contained in the coolant, and a radiator that radiates heat from the coolant to the outside. In addition, the thermal management system may include a heater that heats coolant, and an air conditioning unit (e.g., a heating heater) that uses coolant to cool or heat the interior of a device (e.g., vehicle) containing a fuel cell system. . The thermal management system can maintain the appropriate temperature of not only the fuel cell stack but also the vehicle's electrical components.

Fuel cells for non-vehicles such as construction equipment can adjust the coolant temperature at the stack inlet to the target temperature by discharging heat generated from the stack into the atmosphere through a radiator. At this time, it is important to optimize and control the rotation speed of the cooling fan to match the coolant temperature at the stack inlet to the target temperature. However, such as when the fuel cell stack output is low or the outside temperature is low, the coolant temperature at the stack inlet may be lower than the target temperature even though the cooling fan is controlled to the minimum rotation speed. To solve this problem, turning off the cooling fan may have the opposite effect of causing the coolant temperature at the stack inlet to become higher than the target temperature.

According to embodiments disclosed in this document, a fuel cell system includes: a fuel cell stack; a first cooling line through which first coolant circulates through the fuel cell stack; a first radiator disposed on the first cooling line and cooling the first coolant; a cooling unit in which a plurality of cooling fans are arranged in a plurality of lines and is set to blow outside air to the first radiator; and a control unit connected to the cooling unit and controlling the rotation speed of the plurality of cooling fans based on the coolant temperature at the inlet of the fuel cell stack.

According to an embodiment disclosed in this document, a method of thermal management of a fuel cell system includes turning off a plurality of cooling fans of the fuel cell; Obtaining the coolant temperature at the fuel cell stack inlet; and controlling the rotation speed of the plurality of cooling fans based on the coolant temperature at the stack inlet.

The fuel cell system according to embodiments disclosed in this document can suppress internal damage to the stack and improve power generation efficiency by maintaining the target temperature of the coolant at the inlet of the stack of the fuel cell.

Additionally, the fuel cell system according to the embodiments disclosed in this document can efficiently control thermal management of electrical components to secure cooling performance and prevent deterioration of the lifespan of electrical components.

Additionally, the fuel cell system according to the embodiments disclosed in this document can improve the thermal and power efficiency of the fuel cell by preventing unnecessary cooling fan operation through optimal control of the cooling fan.

In addition, various effects that can be directly or indirectly identified through this document may be provided.

1 is a diagram showing a fuel cell system according to an embodiment disclosed in this document.
Figure 2 is a diagram showing a fuel cell system according to another embodiment disclosed in this document.
Figure 3 is a block diagram of a fuel cell system according to an embodiment disclosed in this document.
Figure 4 is a diagram showing the configuration of a cooling unit according to an embodiment disclosed in this paper.
Figure 5 is a diagram showing the configuration of a cooling unit according to another embodiment disclosed in this paper.
Figure 6 is a flowchart for explaining a cooling fan control process of the cooling unit according to an embodiment disclosed in this document.
Figure 7 is a flowchart for explaining a heat management method of a fuel cell system according to an embodiment disclosed in this paper.
FIG. 8 is a flowchart illustrating a sequential cooling fan control process of a fuel cell system according to an embodiment disclosed in this document.

Hereinafter, various embodiments of the present invention are described with reference to the accompanying drawings. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include various modifications, equivalents, and/or alternatives to the embodiments of the present invention.

In this document, the singular form of a noun corresponding to an item may include one or plural items, unless the relevant context clearly indicates otherwise. In this document: “A or B”, “at least one of A and B”, “at least one of A or B”, “A, B or C”, “at least one of A, B and C” and “A, Each of phrases such as “at least one of B, or C” may include any one of the items listed together in the corresponding phrase, or any possible combination thereof. Terms such as "first", "second", or "first" or "second" may be used simply to distinguish one component from another, and to refer to that component in other respects (e.g., importance or order) is not limited. One (e.g., first) component is said to be “coupled” or “connected” to another (e.g., second) component, with or without the terms “functionally” or “communicatively.” When mentioned, it means that any of the components can be connected to the other components directly (e.g. wired), wirelessly, or through a third component.

Each component (eg, module or program) described in this document may include singular or plural entities. According to various embodiments, one or more of the corresponding components or operations may be omitted, or one or more other components or operations may be added. Alternatively or additionally, multiple components (eg, modules or programs) may be integrated into a single component. In this case, the integrated component may perform one or more functions of each component of the plurality of components in the same or similar manner as those performed by the corresponding component of the plurality of components prior to the integration. . According to various embodiments, operations performed by a module, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or , or one or more other operations may be added.

As used in this document, the term "module", or "part" may include a unit implemented in hardware, software, or firmware, and may include terms such as logic, logic block, component, or circuit. Can be used interchangeably. A module may be an integrated part or a minimum unit of the parts or a part thereof that performs one or more functions. For example, according to one embodiment, the module may be implemented in the form of an application-specific integrated circuit (ASIC).

Various embodiments of this document may be implemented as software (e.g., a program or application) including one or more instructions stored in a storage medium (e.g., memory) that can be read by a machine. For example, the processor of the device may call at least one instruction among one or more instructions stored from a storage medium and execute it. This allows the device to be operated to perform at least one function according to the at least one instruction called. The one or more instructions may include code generated by a compiler or code that can be executed by an interpreter. A storage medium that can be read by a device may be provided in the form of a non-transitory storage medium. Here, 'non-transitory' simply means that the storage medium is a tangible device and does not contain signals (e.g. electromagnetic waves). This term refers to cases where data is stored semi-permanently in the storage medium. There is no distinction between temporary storage cases.

1 to 2 show fuel cell systems according to various embodiments.

Referring to FIG. 1, the fuel cell system for a vehicle is configured such that the first coolant circulates through the fuel cell stack 10 of the vehicle and passes through the first cooling line 110 and power electronic parts 200 of the vehicle. It may include a second cooling line 120 through which a second coolant is circulated. According to an embodiment, the fuel cell system may further include a heat exchanger for exchanging heat between the first coolant and the second coolant, but may be omitted.

The fuel cell system forms a heating loop (heating circulation path, or heating loop) with the first cooling line 110, or a first connection line 130 to form a cooling line with the first cooling line 110, It may include a second connection line 150 and a third connection line 140. The first coolant may be cooled or heated while circulating through the first connection line 130, the second connection line 150, or the third connection line 140. For example, the first cooling line 110 forms a heating loop with the first connection line 130 and the third connection line 140 to secure cold start capability during the initial starting state of the vehicle, and during driving, the fuel cell A cooling loop through which the first coolant passes through the first radiator 60 may be formed so that heat generated in the stack 10 can be discharged to the outside. According to another embodiment, when the outside air is as high as a specified temperature, the first cooling line 110 does not form a heating loop and the fuel cell system can secure starting ability through the heat of the fuel cell stack 10. On the first cooling line 110 through which the first coolant circulates, a fuel cell stack 10, a first valve 20, a first pump 30, a second valve 40, and a first radiator 60 are installed. can be placed.

The fuel cell stack 10 (or may be referred to as a 'fuel cell') is a structure capable of producing electricity through a redox reaction of fuel (eg, hydrogen) and an oxidizing agent (eg, air). can be formed. As an example, the fuel cell stack 10 is a membrane electrode assembly (MEA) with catalyst electrode layers where electrochemical reactions occur on both sides of the electrolyte membrane through which hydrogen ions move, and evenly distributes the reaction gases. A gas diffusion layer (GDL) that plays a role in transmitting the generated electrical energy, a gasket and fastening device to maintain the airtightness and appropriate fastening pressure of the reaction gases and the first coolant, and the reaction gases and the first coolant. It may include a bipolar plate that moves coolant.

In the fuel cell stack 10, hydrogen as a fuel and air (oxygen) as an oxidizing agent are supplied to the anode and cathode of the membrane electrode assembly through the flow path of the separator, respectively. Hydrogen is supplied to the anode, and air is supplied to the anode. can be supplied to the cathode. The hydrogen supplied to the anode is decomposed into hydrogen ions (protons) and electrons (electrons) by the catalyst in the electrode layer formed on both sides of the electrolyte membrane, and only hydrogen ions are selectively passed through the electrolyte membrane, which is a cation exchange membrane, and transferred to the cathode. At the same time, electrons can be transferred to the cathode through the conductive gas diffusion layer and separator plate. At the cathode, hydrogen ions supplied through the electrolyte membrane and electrons transferred through the separator meet oxygen in the air supplied to the cathode by the air supply device, causing a reaction to generate water. Due to the movement of hydrogen ions that occurs at this time, a flow of electrons occurs through the external conductor, and current can be generated through this flow of electrons.

The first valve 20 may change the flow path of the first coolant on the first cooling line 110 to the first connection line 130 or the fuel cell stack 10 where the heater 50 is disposed. For example, the first valve 20 may be connected to one end of the first pump 30, one end of the first connection line 130, and one end of the fuel cell stack 10 on the first cooling line 110. there is. The first valve 20 may include various valve means that can selectively change the flow path of the first coolant. For example, the first valve 20 may be a three-way valve. In this case, the first valve 20 includes a first port 21 connected to the first cooling line 110 so that the first coolant pumped by the first pump 30 flows in, and a first valve 20. A second port 22 connected to the first cooling line 110 so that the first coolant passing through flows into the fuel cell stack 10, and a third port connected to one end of the first connection line 130 ( 23) may be included. By opening and closing the second port 22 and the third port 23 of the first valve 20, the flow path of the first coolant is connected to the heater 50 or the fuel cell stack 10 of the first connection line 130. can be converted to That is, when the second port 22 is open and the third port 23 is blocked, the first coolant flows into the fuel cell stack 10. Conversely, when the third port 23 is open and the second port 22 is blocked, the first coolant flows into the fuel cell stack 10. ) is blocked, the first coolant can flow into the heater 50 through the first connection line 130.

The first connection line 130 may form a heating loop (heating circulation path) with the first cooling line 110 to heat the first coolant. For example, the first coolant flowing along the first connection line 130 may be heated while passing through the heater 50 installed in the first connection line 130. One end of the first connection line 130 is connected to the first cooling line 110 at a first point located between the outlet of the first pump 30 and the fuel cell stack 10, and the first connection line ( The other end of 130) may be connected to the first cooling line 110 at a second point located between the inlet of the first pump 30 and the fuel cell stack 10. Here, the inlet of the first pump 30 may be defined as an inlet through which the first coolant flows into the first pump 30. Additionally, the outlet of the first pump 30 may be defined as an outlet through which the first coolant passing through the first pump 30 is discharged. In addition, between the outlet of the first pump 30 and the fuel cell stack 10, the first coolant discharged from the first pump 30 reaches the first coolant inlet (not shown) of the fuel cell stack 10. It can be defined as a flowing section. In addition, between the inlet of the first pump 30 and the fuel cell stack 10, the first coolant discharged from the coolant outlet (not shown) of the fuel cell stack 10 reaches the inlet of the first pump 30. It can be defined as a flowing section.

The first pump 30 may be set to forcibly flow the first coolant. The first pump 30 may include various means for pumping the first coolant, and the type and number of the first pump 30 are not limited in this document.

The second valve 40 may change the flow path of the first coolant on the first cooling line 110 to the first radiator 60 or the fuel cell stack 10. For example, the second valve 40 is provided on the first cooling line 110 to be located between the first pump 30 and the first radiator 60, and is connected to one end of the third connection line 140. And it may be connected to the outlet of the first radiator 60. The second valve 40 may include various valve means that can selectively switch the flow path of the first coolant to the first radiator 60 or the fuel cell stack 10. For example, the second valve 40 may be a four-way valve or a three-way valve. In the case of a three-way valve, the second valve 40 is connected to the first port 41 connected to the third connection line 140, and the first cooling line 110 so that the first coolant passing through the first radiator 60 flows in. ) and a third port 44 connected to the first cooling line 110 so that the first coolant flows into the first pump 30, and a second port 44 that is a four-way valve. The valve 40 may further include a third port 43 connected to one end of the second connection line 150. By opening and closing the first port 41 or the second port 42 of the second valve 40, the flow path of the first coolant can be switched to the first radiator 60 or the fuel cell stack 10. That is, when the first port 41 is opened and the second port 42 is blocked, the first coolant flows into the fuel cell stack 10 without passing through the first radiator 60, and conversely, the second port 42 ) is open and the first port 41 is blocked, the first coolant may pass through the first radiator 60 and then flow into the fuel cell stack 10.

The second connection line 150 may form a heating loop with the first cooling line 110 to heat the air conditioning unit (HAVC UNIT) 90. As an example, the second connection line 150 may form a loop that heats a heater (not shown) of the air conditioning unit 90. One end of the second connection line 150 undergoes first cooling between the first point (the point where one end of the first connection line 130 is connected to the first cooling line 110) and the inlet of the fuel cell stack 10. It is connected to the line 110, and some of the first coolant may circulate through the second connection line 150. The other end of the second connection line 150 is connected to the first pump 30 and the second point (the point where the other end of the first connection line 130 is connected to the first cooling line 110). It can be connected to the cooling line 110.

The second connection line 150 may be provided with an ion filter 95 that filters ions of the first coolant that has passed through the air conditioning unit 90. If the electrical conductivity of the first coolant increases due to corrosion or exudation of the system, electricity flows into the first coolant, causing a problem in which the fuel cell stack 10 is short-circuited or current flows toward the first coolant. , the first coolant must be able to maintain low electrical conductivity. The ion filter 95 may be set to remove ions contained in the first coolant so that the electrical conductivity of the first coolant can be maintained below a certain level. In this way, during cold starting when the supply of the first coolant flowing to the fuel cell stack 10 is blocked (the second port 22 of the first valve 20 is blocked), the first coolant flows through the first connection line 130. ), the ion filter 95 provided in the second connection line 150 even during cold start by circulating (temperature increase loop) through the heater 50 and simultaneously circulating along the second connection line 150. ) Filtering (removal of ions contained in the first coolant) is possible. Therefore, it is possible to obtain the advantageous effect of maintaining the electrical conductivity of the first coolant flowing into the fuel cell stack 10 immediately after cold starting below a certain level.

The third connection line 140 may form a cooling loop with the first cooling line 110 to cool the first coolant. As an example, one end of the third connection line 140 is connected to the first cooling line 110 between the first pump 30 and the first radiator 60, and the other end of the third connection line 140 may be connected to the first cooling line 110 between the coolant outlet of the fuel cell stack 10 and the first radiator 60.

The first radiator 60 may be set to cool the first coolant. The first radiator 60 may be formed in various structures capable of cooling the first coolant, and the present invention is not limited or limited by the type and structure of the first radiator 60. The first radiator 60 may be connected to the first reservoir 62 where the first coolant is stored.

The fuel cell system includes a first temperature sensor 112 that measures the temperature of the first coolant between the fuel cell stack 10 and a first point (the first valve 20), and a first connection line 130. A second temperature sensor 114 that measures the temperature of the first coolant between the other end and the first pump 30, and a third temperature sensor 116 that measures the temperature of the first coolant in the heater 50. It can be included. The fuel cell system determines the inflow rate of the first coolant flowing into the fuel cell stack 10 based on the temperature measured by the first temperature sensor 112, the second temperature sensor 114, and the third temperature sensor 116. can be controlled. For example, if the measured temperature of the first coolant circulating along the first cooling line 110 is lower than a preset target temperature, the inflow rate of the first coolant may be controlled to be lower than the preset set flow rate. In this way, when the measured temperature of the first coolant is low, the inflow rate of the first coolant flowing into the fuel cell stack 10 is controlled to be low, so that the temperature of the first coolant stagnant inside the fuel cell stack 10 and The advantageous effect of minimizing thermal shock and performance degradation due to the difference between the temperatures of the first coolant flowing into the fuel cell stack 10 can be obtained.

The second cooling line 120 is configured to pass through the vehicle's electrical components 200, and the second coolant can circulate along the second cooling line 120. Here, the electrical components 200 of the vehicle can be understood as components that use the vehicle's power source as an energy source, and the present invention is not limited or limited by the type and number of the electrical components 200. As an example, the electrical component 200 includes a bi-directional high voltage DC-DC converter (BHDC) 210 and the fuel cell stack 10 provided between the fuel cell stack 10 and the high-voltage battery (not shown) of the vehicle. BPCU (blower pump control unit) 220 that controls a blower (not shown) that supplies outdoor air for driving, and LDC (low-voltage DC-DC converter) that converts high DC voltage supplied from a high voltage battery into low DC voltage. It may include at least one of (230), an air compressor (ACP) 240 that compresses the air supplied to the fuel cell stack 10, and an air cooler (250). Although not shown in FIGS. 1 and 2, the electrical component 200 may further include a DC-DC buck/boost converter.

A second pump 205 may be disposed on the second cooling line 120 to forcibly flow the second coolant. The second pump 205 may include a pumping means capable of pumping the second coolant, and the type and characteristics of the second pump 205 are not limited or limited.

A second radiator 70 may be disposed on the second cooling line 120 to cool the second coolant. The second radiator 70 may be formed in various structures capable of cooling the second coolant, and the type and structure of the second radiator 70 are not limited or limited. The second radiator 70 may be connected to the second reservoir 72 where the second coolant is stored.

According to an embodiment, the first radiator 60 and the second radiator 70 may be configured to be cooled simultaneously by one cooling unit 400 as shown in FIG. 1. For example, the first radiator 60 and the second radiator 70 are arranged side by side, and the cooling unit 80 may be set to blow outside air to the first radiator 60 and the second radiator 70. . By allowing the first radiator 60 and the second radiator 70 to be cooled simultaneously by one cooling unit 400, the structure of the fuel cell system can be simplified and design freedom and space utilization can be improved. , power consumption for cooling the first radiator 60 and the second radiator 70 can be minimized. This structure of the cooling unit 400 may be referred to as a ‘dual type’.

According to another embodiment, as shown in FIG. 2, the first cooling unit 81 for cooling the first radiator 60 and the second cooling unit 420 for cooling the second radiator 70 are separately installed. can be placed. In this case, the fuel cell system may exclude parameters related to the thermal load of the electrical component 200 when controlling the rotation speed of the first cooling unit 410. The structure of the cooling units 410 and 420 may be referred to as 'multi-type'.

Figure 3 is a block diagram of a fuel cell system according to an embodiment disclosed in this document.

Figure 4 is a diagram showing the configuration of a cooling unit according to an embodiment disclosed in this paper.

3 and 4, in the fuel cell system 1, the control unit 300 is connected to the cooling unit 400 and controls the rotation speed of the plurality of cooling fans 401 to 406 constituting the cooling unit 400. You can control it. The fuel cell system 1 can raise the coolant temperature on its own using the heat generated by the stack, allowing the coolant temperature at the stack inlet to reach the target temperature. In addition, by maintaining the coolant temperature at the stack inlet and the coolant temperature at the electrical component inlet at the target temperature, damage to the stack and electrical components can be suppressed and power generation efficiency can be improved.

The cooling unit 400 may blow outside air to the first radiator 60. At this time, the cooling unit 400 can control the temperature of the first coolant passing through the first radiator 60 by blowing outside air to the first radiator 60 .

According to an embodiment, the cooling unit 400 may include a plurality of cooling fans 401 to 406 arranged in a plurality of lines. At this time, at least one cooling fan may be placed in each line. For example, the cooling unit 400 may form a plurality of lines by arranging a plurality of cooling fans 401 to 406 in a plurality of rows or columns at regular intervals. For example, in FIG. 4, the cooling unit 400 includes a plurality of cooling fans 401 to 406 arranged in three rows, and two cooling fans may be arranged in each row. However, this is only an example and the number of rows or columns and the number of cooling fans arranged in each row or column are not limited.

Here, the plurality of lines of the cooling unit 400 can be ordered based on rows or columns. For example, the plurality of lines of the cooling unit 400 can be set as the first line starting from the line closest to the stack entrance. . .

According to an embodiment, the control unit 300 may control the rotation speed of the plurality of cooling fans 401 to 406 based on the temperature of the first coolant at the inlet of the fuel cell stack. The control unit 300 can control the rotation speed of the plurality of cooling fans 401 to 406 to be the same, control the rotation speed differently for each line, and control the rotation speed of each of the plurality of cooling fans 401 to 406. The number can also be controlled differently.

According to the embodiment, when the first coolant temperature at the stack inlet is less than a preset temperature while the plurality of cooling fans 401 to 406 are turned off, the control unit 300 cools the plurality of cooling fans 400. The cooling fan of the first line among the fans 401 to 406 can be controlled to have a minimum rotation speed. For example, in FIG. 4, the control unit 300 may control the cooling fans 401 and 402 arranged in the first line to have the minimum rotation speed.

According to an embodiment, the minimum rotation speed of the plurality of cooling fans 401 to 406 may be set based on the power generation capacity of the fuel cell system, the heat generation amount of the fuel cell, the number of cooling fans disposed, the coolant flow rate, etc.

Meanwhile, the preset temperature may include the target temperature of the first coolant at the stack inlet. For example, the target temperature of the first coolant at the stack inlet may be set differently depending on the type of vehicle in which the fuel cell system 1 is used, whether it is a non-vehicle, the power generation capacity of the fuel cell, etc.

According to an embodiment, the first coolant temperature at the stack inlet may be obtained based on the first temperature sensor 112, etc. For example, the first temperature sensor 112 may measure the temperature of the first coolant at the stack entrance, measure the temperature of the first coolant at a point other than the stack entrance, and control unit 300 may measure the temperature of the first coolant at a point other than the stack entrance. Based on this, the temperature of the first coolant at the stack inlet may be predicted.

According to the embodiment, the control unit 300 controls the cooling fan in the first line among the plurality of cooling fans 401 to 406 to have the minimum rotation speed, and then after a preset time has elapsed, the first coolant temperature at the stack inlet and the preset Temperatures can be compared. Since it takes a certain amount of time for the temperature of the first coolant to change after the control of the cooling fan by the control unit 300, in order to control the cooling unit 400 through more accurate temperature comparison of the first coolant, the control unit 300 sets the preset time. After this lapse, the first coolant temperature can be compared with the preset temperature. Meanwhile, the preset time can be set differently depending on the heat generation amount of the fuel cell, the coolant flow rate, the number of installed cooling fans, etc.

At this time, when the temperature of the first coolant at the stack inlet is higher than a preset temperature, the control unit 300 may control the second line cooling fan among the plurality of cooling fans 401 to 406 to have the minimum rotation speed. For example, in FIG. 4, the control unit 300 may control the cooling fans 403 and 404 arranged in the second line to the minimum rotation speed. If the temperature of the first coolant at the stack inlet is higher than the preset target temperature, the first coolant temperature must be lowered than the current temperature, so the control unit 300 may additionally operate some of the cooling fans that were turned off. At this time, for efficient control of the cooling fan, the control unit 300 does not operate the cooling fan indiscriminately, but sequentially controls the cooling fan according to the order in which they are arranged in the plurality of lines of the cooling unit 400. .

Additionally, when the temperature of the first coolant at the stack inlet is below a preset temperature, the controller 300 may control to turn off at least one cooling fan among the cooling fans in the first line. For example, in FIG. 4, the controller 300 may control to turn off one of the cooling fans 401 and 402 arranged in the first line. If the temperature of the first coolant at the stack inlet is lower than the preset temperature, the first coolant temperature must be raised to the current temperature, so the control unit 300 turns off some of the cooling fans operating at the minimum rotation speed to control the cooling water by the cooling unit 400. 1 The cooling effect of the coolant can be reduced. Through this, the control unit 300 can ensure that the temperature of the first coolant is sufficiently raised so that the temperature of the first coolant sufficiently reaches the target temperature.

The cooling fan control described above can be equally applied to a plurality of lines constituting the cooling unit 400. That is, according to the embodiment, the control unit 300 controls the cooling fan in the ith line among the plurality of cooling fans 401 to 406 to have the minimum rotation speed, and then after a preset time has elapsed, the temperature of the first coolant at the stack inlet is increased. You can compare the previously set temperature. At this time, when the temperature of the first coolant at the stack inlet is higher than a preset temperature, the control unit 300 may control the cooling fan of the i+1th line among the plurality of cooling fans 401 to 406 to have the minimum rotation speed. . Additionally, when the temperature of the first coolant at the stack inlet is less than a preset temperature, the controller 300 may control to turn off at least one cooling fan among the cooling fans of the i-th line.

Through the repetitive and sequential cooling fan control process of the control unit 300 as described above, the fuel cell system 1 efficiently controls the plurality of cooling fans 401 to 406 arranged in the cooling unit 400 to reduce power consumption and The efficiency of thermal management can be reconsidered.

According to an embodiment, when the first coolant temperature at the stack inlet is less than a preset temperature while only one cooling fan among the plurality of cooling fans 401 to 406 operates at the minimum rotation speed, the control unit 300 operates the plurality of cooling fans 401 to 406. The cooling fans 401 to 406 can be controlled to turn off. In this case, even though only one cooling fan was controlled to the minimum rotation speed, it may be determined that the temperature of the first coolant was not sufficiently increased to reach the target temperature, and the control unit 300 may control all of the plurality of cooling fans 401 to 406. can be turned off to induce an increase in the temperature of the first coolant.

Figure 5 is a diagram showing the configuration of a cooling unit according to another embodiment disclosed in this paper.

Referring to FIG. 5, the cooling unit 400 may include a first cooling unit 410 and a second cooling unit 420, and each of the first cooling unit 410 and the second cooling unit 420 A plurality of cooling fans 411 to 413 and 421 to 423 are arranged in a plurality of lines, and at least one cooling fan may be arranged in each line.

According to the embodiment, the fuel cell system 1 includes a plurality of electrical components 200, a second cooling line 120 through which the second coolant circulates through the plurality of electrical components 200, and a second cooling line 120. ) and may further include a second radiator 70 that cools the second coolant.

At this time, the cooling unit 400 may blow outside air to at least one of the first radiator 60 and the second radiator 70. In addition, the control unit 300 controls the number of rotations of the plurality of cooling fans 411 to 413 and 421 to 423 based on at least one of the first coolant temperature at the fuel cell stack inlet and the second coolant temperature at the inlet of the plurality of electrical components. You can control it.

According to the embodiment, the cooling unit 400 includes a first cooling unit 410 set to blow outside air to the first radiator 60 and a second cooling unit 420 set to blow outside air to the second radiator 70. may include. At this time, the first cooling unit 410 and the second cooling unit 420 may be arranged in series or parallel. For example, in FIG. 5, the first cooling unit 410 and the second cooling unit 420 are shown as being arranged in parallel, but in some cases, they may be arranged in series.

According to an embodiment, the first cooling unit 410 and the second cooling unit 420 may each have a plurality of lines and a plurality of cooling fans 411 to 413 and 421 to 423 may be disposed. For example, when the cooling unit 400 has a plurality of cooling fans 411 to 413 and 421 to 423 arranged in two rows, the cooling fans 411 to 413 in the first row constitute the first cooling unit 410. And, the cooling fans 421 to 423 in the second row may form the second cooling unit 420. The arrangement of the plurality of cooling fans 411 to 413 and 421 to 423 shown in FIG. 5 is only an example and is not limited thereto. The plurality of cooling fans 411 to 413 and 421 to 423 in FIG. 5 may be substantially the same as the plurality of cooling fans 401 to 406 in FIG. 4 .

According to the embodiment, a plurality of cooling fans 411 to 413, 421 to 423 disposed in the cooling unit 400 are provided based on the location, size, capacity, etc. of the first radiator 60 and the second radiator 70. It can be arranged separately into a first cooling unit 410 and a second cooling unit 420.

According to an embodiment, the control unit 300 controls the rotation speed of the first cooling unit 410 based on the result of comparing the first coolant temperature at the stack inlet and the first temperature, and controls the rotation speed of the first cooling unit 410 at the entrance of the plurality of electrical components. The rotational speed of the second cooling unit 420 may be controlled based on the result of comparing the coolant temperature and the second temperature.

According to an embodiment, the first temperature may include a target temperature of the first coolant temperature at the stack inlet, and the second temperature may include a target temperature of the second coolant temperature at the inlet of the plurality of electrical components. The first temperature and the second temperature may be set differently based on the heating value of the stack and the electrical components, usage purpose, coolant flow rate, etc. The first temperature may be substantially the same as the preset temperature described above.

In general, since the heat generation amount of the stack and the electrical components are different, controlling the temperature of the first coolant through the stack and the second coolant through a plurality of electrical components by separating the cooling unit 400 provides optimal efficiency. It may be advantageous to: Accordingly, the fuel cell system 1 includes a cooling unit 400 with a first cooling unit 410 that blows external air to the first radiator 60 and a second cooling unit that blows external air to the second radiator 70 ( 420) can be separated and controlled. Through this, the fuel cell system 1 can increase thermal management efficiency by controlling the first cooling unit 410 to control the temperature of the first coolant and controlling the second cooling unit 420 to control the second coolant temperature. there is. At this time, the fuel cell system 1 may exclude parameters related to the thermal load of the electrical component 200 when controlling the rotation speed of the first cooling unit 410. Conversely, the fuel cell system 1 may exclude parameters related to the heat load of the stack when controlling the rotation speed of the second cooling unit 420.

According to an embodiment, the control unit 300 may compare the second coolant temperature at the inlet of the electrical component with the second temperature after a preset time has elapsed. At this time, when the temperature of the second coolant at the inlet of the electrical component is higher than the second temperature, the control unit 300 may control the cooling fan of the second line among the plurality of cooling fans of the second cooling unit 420 to have the minimum rotation speed. . In addition, the control unit 300 may control to turn off at least one cooling fan among the cooling fans in the first line of the second cooling unit 420 when the temperature of the second coolant at the inlet of the electrical component is lower than the second temperature. .

The cooling fan control of the control unit 300 described above may be equally applied to a plurality of lines constituting the second cooling unit 420. According to an embodiment, the control unit 300 may control the cooling fan of the ith (i is a natural number) line among the plurality of cooling fans of the second cooling unit 420 to have the minimum rotation speed. At this time, the control unit 300 compares the second temperature with the second coolant temperature at the inlet of the plurality of electrical components after a preset time has elapsed, and when the second coolant temperature at the inlet of the plurality of electrical components is higher than the second temperature. Among the plurality of cooling fans of the second cooling unit 420, the cooling fan of the i+1th line can be controlled to have the minimum rotation speed. Additionally, the control unit 300 controls the temperature of the second cooling water at the inlet of the plurality of electrical components. If is less than the second temperature, at least one cooling fan among the cooling fans in the ith row among the plurality of cooling fans of the second cooling unit 420 may be controlled to be turned off.

Through the repetitive and sequential cooling fan control process of the control unit 300 as described above, the control unit 300 efficiently controls the plurality of cooling fans 411 to 413 arranged in the second cooling unit 420 to reduce power consumption and The efficiency of thermal management can be reconsidered.

Figure 6 is a flowchart for explaining the cooling fan control process of the cooling unit according to an embodiment disclosed in this document.

Referring to FIG. 6, in step S10, when the first coolant temperature at the stack inlet is less than a preset temperature while the plurality of cooling fans 401 to 406 of the cooling unit 400 are turned off, the control unit 300 performs cooling. Among the plurality of cooling fans 401 to 406 of the unit 400, the first line cooling fan may be controlled to have a minimum rotation speed.

In step S20, if the temperature of the first coolant at the stack inlet is higher than the preset temperature after a preset time has elapsed, the control unit 300 controls the cooling fan in the second line among the plurality of cooling fans 401 to 406 to have the minimum rotation speed. And, when the temperature of the first coolant at the stack inlet is less than a preset temperature, at least one cooling fan of the first line cooling fans can be controlled to be turned off.

In step S30, if the temperature of the first coolant at the stack inlet is less than a preset temperature while only one cooling fan among the plurality of cooling fans 401 to 406 of the cooling unit operates at the minimum rotation speed, the control unit 300 operates the plurality of cooling fans 401 to 406. The cooling fans 401 to 406 can be controlled to turn off.

Figure 7 is a flowchart for explaining a heat management method of a fuel cell system according to an embodiment disclosed in this paper.

Referring to FIG. 7, the thermal management method of the fuel cell system includes turning off a plurality of cooling fans of the fuel cell (S100), obtaining the coolant temperature at the fuel cell stack inlet (S200), and calculating the coolant temperature at the stack inlet. It may include a step (S300) of controlling the rotation speed of a plurality of cooling fans based on the cooling speed. Here, the coolant may be substantially the same as the first coolant.

In step S100, the control unit 300 may turn off all of the plurality of cooling fans 401 to 406. This can be understood as a preparatory operation for optimal control of the rotation speed of the plurality of cooling fans 401 to 406.

In step S200, the first temperature sensor 112, etc. may acquire the coolant temperature at the entrance of the fuel cell stack. The coolant temperature may be calculated through direct measurement or indirect calculation.

In step S300, the control unit 300 may control the rotation speed of the plurality of cooling fans based on the temperature of the coolant at the stack inlet. A specific cooling fan control method of the control unit 300 will be described later with reference to FIG. 8.

FIG. 8 is a flowchart illustrating a sequential cooling fan control process of a fuel cell system according to an embodiment disclosed in this document.

Referring to FIG. 8, in step S310, the control unit 300 may compare the coolant temperature at the stack inlet and a preset temperature.

In step S320, the control unit 300 may control the cooling fan of the ith line among the plurality of cooling fans to the minimum rotation speed.

In steps S330 and S340, the control unit 300 may compare the coolant temperature at the stack inlet with the preset temperature after a preset time has elapsed.

In step S350, when the coolant temperature at the stack inlet is higher than a preset temperature, the control unit 300 may control the cooling fan of the i+1th line among the plurality of cooling fans to have the minimum rotation speed.

In step S360, the control unit 300 may control to turn off at least one cooling fan among the cooling fans of the i-th line when the coolant temperature at the stack inlet is less than a preset temperature. Through the repetitive and sequential cooling fan control process of the control unit 300 as described above, the fuel cell system 1 efficiently controls the plurality of cooling fans 401 to 406 arranged in the cooling unit 400 to reduce power consumption and The efficiency of thermal management can be reconsidered.

In the above, just because all the components constituting the embodiments disclosed in this document are described as being combined or operated in combination, the embodiments disclosed in this document are not necessarily limited to these embodiments. That is, as long as it is within the scope of the purpose of the embodiments disclosed in this document, all of the components may be operated by selectively combining one or more of them.

In addition, terms such as “include,” “comprise,” or “have,” as used above, mean that the corresponding component may be contained, unless specifically stated to the contrary, and thus exclude other components. It should be interpreted as being able to include other components. All terms, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the embodiments disclosed in this document belong, unless otherwise defined. Commonly used terms, such as terms defined in dictionaries, should be interpreted as consistent with the contextual meaning of the relevant technology, and should not be interpreted in an idealized or overly formal sense unless explicitly defined in this document.

The above description is merely an illustrative explanation of the technical idea disclosed in this document, and those skilled in the art in the technical field to which the embodiments disclosed in this document belong will understand without departing from the essential characteristics of the embodiments disclosed in this document. Various modifications and variations will be possible. Accordingly, the embodiments disclosed in this document are not intended to limit the technical idea of the embodiments disclosed in this document, but rather to explain them, and the scope of the technical idea disclosed in this document is not limited by these embodiments. The scope of protection of the technical ideas disclosed in this document shall be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope shall be interpreted as being included in the scope of rights of this document.

Claims (14)

fuel cell stack;
a first cooling line through which first coolant circulates through the fuel cell stack;
a first radiator disposed on the first cooling line and cooling the first coolant;
a cooling unit in which a plurality of cooling fans are arranged in a plurality of lines and is set to blow outside air to the first radiator; and
A fuel cell system comprising a control unit connected to the cooling unit and controlling rotational speeds of the plurality of cooling fans based on the temperature of the first coolant at the inlet of the fuel cell stack.
According to paragraph 1,
The control unit,
When the first coolant temperature at the stack inlet is less than a preset temperature while the plurality of cooling fans in the cooling unit are OFF, the cooling fan in the first line among the plurality of cooling fans in the cooling unit is set to the minimum rotation speed. A fuel cell system that is controlled to have
According to paragraph 2,
The control unit,
After a preset time has elapsed, by comparing the first coolant temperature at the stack inlet with the preset temperature,
When the temperature of the first coolant at the stack inlet is equal to or higher than the preset temperature, controlling the second line cooling fan among the plurality of cooling fans to have the minimum rotation speed,
A fuel cell system that controls to turn off at least one cooling fan among the cooling fans in the first line when the temperature of the first coolant at the stack inlet is less than the preset temperature.
According to paragraph 1,
The control unit
Controlling the cooling fan of the ith (i is a natural number) line among the plurality of cooling fans to have a minimum rotation speed, and comparing the first cooling water temperature at the stack inlet with the preset temperature after a preset time has elapsed,
If the temperature of the first coolant at the stack inlet is higher than the preset temperature, control the cooling fan of the i+1th line among the plurality of cooling fans to have the minimum rotation speed,
A fuel cell system that controls to turn off at least one cooling fan among the cooling fans in the ith row among the plurality of cooling fans when the temperature of the first coolant at the stack inlet is less than the preset temperature.
According to paragraph 4,
The control unit,
When the temperature of the first coolant at the stack inlet is less than the preset temperature while only one cooling fan among the plurality of cooling fans of the cooling unit operates at the minimum rotation speed, the plurality of cooling fans are turned off (OFF) ) A fuel cell system that is controlled to operate.
According to paragraph 1,
Multiple electrical components;
a second cooling line through which second coolant circulates through the plurality of electrical components;
It further includes a second radiator disposed on the second cooling line and cooling the second coolant,
The cooling unit blows outside air to at least one of the first radiator and the second radiator,
The control unit controls the rotation speed of the plurality of cooling fans based on at least one of the first coolant temperature at the inlet of the fuel cell stack and the second coolant temperature at the inlet of the plurality of electrical components.
According to clause 6,
The cooling unit,
a first cooling unit in which the plurality of cooling fans are arranged in a plurality of lines and is set to blow outside air to the first radiator; and
The plurality of cooling fans are arranged in a plurality of lines and include a second cooling unit configured to blow outside air to the second radiator,
A fuel cell system in which the first cooling unit and the second cooling unit are arranged in parallel.
In clause 7,
The control unit,
Controlling the rotation speed of the first cooling unit based on a result of comparing the first temperature with the first coolant temperature at the stack inlet,
A fuel cell system that controls the rotation speed of the second cooling unit based on a result of comparing the second temperature with the second coolant temperature at the inlet of the plurality of electrical components.
According to clause 8,
The control unit,
After a preset time has elapsed, the second coolant temperature at the inlet of the electrical component is compared with the second temperature,
When the temperature of the second coolant at the inlet of the electrical component is higher than the second temperature, the cooling fan in the second line among the plurality of cooling fans in the second cooling unit is controlled to have a minimum rotation speed,
A fuel cell system that controls to turn off at least one cooling fan among the cooling fans of the first line of the second cooling unit when the temperature of the second coolant at the inlet of the electrical component is lower than the second temperature.
According to clause 8,
The control unit
The cooling fan of the ith (i is a natural number) line among the plurality of cooling fans of the second cooling unit is controlled to have a minimum rotation speed, and after a preset time has elapsed, the second cooling water temperature at the inlet of the plurality of electrical components and the By comparing the second temperature,
When the second coolant temperature at the inlet of the plurality of electrical components is higher than the second temperature, controlling the cooling fan of the i+1th line of the plurality of cooling fans of the second cooling unit to have the minimum rotation speed,
When the second coolant temperature at the inlet of the plurality of electrical components is less than the second temperature, controlling to turn off at least one cooling fan among the cooling fans in the ith row among the plurality of cooling fans of the second cooling unit. Fuel cell system.
According to clause 10,
The control unit,
When the second cooling water temperature at the inlet of the plurality of electrical components is less than the second temperature while only one cooling fan among the plurality of cooling fans of the second cooling unit operates at the minimum rotation speed, the second cooling A fuel cell system that controls the plurality of cooling fans to be turned off.
Turning off a plurality of cooling fans of the fuel cell;
Obtaining the coolant temperature at the fuel cell stack inlet; and
A thermal management method for a fuel cell system comprising controlling the rotation speed of the plurality of cooling fans based on the coolant temperature at the stack inlet.
According to clause 12,
The step of controlling the rotation speed of the plurality of cooling fans based on the coolant temperature at the stack inlet,
Comparing the coolant temperature at the fuel cell stack inlet and a preset temperature;
If the coolant temperature at the fuel cell stack inlet is below the preset temperature, controlling the cooling fan in the first line among the plurality of cooling fans to the minimum rotation speed; and
After a preset time has elapsed, the coolant temperature at the stack inlet is compared with the preset temperature, and if the coolant temperature at the stack inlet is higher than the preset temperature, the cooling fan of the second line among the plurality of cooling fans is adjusted to the minimum rotation speed. and controlling to turn off at least one cooling fan among the cooling fans in the first line among the plurality of cooling fans when the coolant temperature at the stack inlet is below the preset temperature. Heat management methods.
According to clause 12,
The step of controlling the rotation speed of the plurality of cooling fans based on the coolant temperature at the stack inlet,
Controlling the cooling fan of the ith (i is a natural number) line among the plurality of cooling fans to have a minimum rotation speed;
Comparing the coolant temperature at the stack inlet with the preset temperature after a preset time has elapsed; and
When the coolant temperature at the stack inlet is above the preset temperature, the cooling fan on the i+1th line among the plurality of cooling fans is controlled to have the minimum rotation speed, and when the coolant temperature at the stack inlet is below the preset temperature, the cooling fan on the i+1th line is controlled to have a minimum rotation speed. A heat management method for a fuel cell system including the step of controlling to turn off at least one cooling fan among the cooling fans of the ith line among a plurality of cooling fans.

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