Fuel cell system and control method using the same

Abstract

The present invention relates to a fuel cell system and a control method using the same. [Solution] The present invention may include a propeller blade connected to a rotor for the flight of an aircraft, a main radiator and a sub-radiator arranged to release heat from the cooling water by the downdraft generated by the rotation of the propeller blade, and a control unit that controls the supply of the cooling water to at least one or more of the main radiator and sub-radiator based on the operating mode of the aircraft.

Description

Technical Field

[0001] The present invention relates to a fuel cell system used in a flying object and a control method using the same.

Background Art

[0002] Fuel cells are being increasingly used as a highly efficient clean energy source. Among various types of fuel cells, in particular, polymer electrolyte membrane fuel cells (PEMFCs) operate at a lower temperature compared to other forms of fuel cells, have a short startup time, and exhibit rapid response characteristics to load changes.

[0003] Moreover, polymer electrolyte membrane fuel cells are highly efficient, with high current density and output density. They are not very sensitive to pressure changes in the reaction gases (hydrogen and oxygen in air) and can produce various ranges of output. For these reasons, they can be applied in various fields such as power sources for pollution-free vehicles, home power generation, mobile and military power sources.

[0004] On the other hand, in reality, in order to obtain the required potential for vehicles (Vehicle) and drones (Drone), it is necessary to stack unit cells by the required potential, and the stack formed by stacking unit cells in this way is called a stack (or fuel cell stack). The potential generated by one unit cell is about 1.2V, and a large number of cells are stacked in series to supply the power required for the load.

[0005] Each unit cell includes a membrane electrode assembly (MEA). On both sides of the polymer electrolyte membrane through which hydrogen ions are transmitted in the membrane electrode assembly, an anode electrode supplied with hydrogen and a cathode electrode supplied with air (oxygen) are provided. In addition, a gas diffusion layer is arranged outside the anode electrode and the cathode electrode including the catalyst layer, and the fuel cell stack is formed by sequentially stacking such a membrane electrode assembly, a separator in which reaction gas and cooling water flow paths are formed.

[0006] Fuel cell systems generate electrical energy and produce heat as a reaction byproduct; therefore, a device to cool the stack is essential to prevent the stack temperature from rising. [Overview of the project] [Problems that the invention aims to solve]

[0007] The embodiments of the present invention aim to provide a fuel cell system and a control method therefor that can efficiently release the heat generated in a fuel cell system used in an aircraft.

[0008] The technical problems of the present invention are not limited to those mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0009] An embodiment of the present invention may include a fuel cell system comprising: propeller blades connected to a rotor for the flight of an aircraft; a main radiator and a sub-radiator arranged to release heat from cooling water by the downdraft generated by the rotation of the propeller blades; and a control unit that controls the supply of the cooling water to at least one or more of the main radiator and sub-radiator based on the operating mode of the aircraft.

[0010] In one embodiment, the operating modes of the aircraft include an initial startup mode, an emergency operation mode, a normal operation mode, and a maximum output mode, and the control unit can control the supply of coolant to the main radiator when the aircraft is in the initial startup mode or the emergency operation mode, to supply the coolant to the sub-radiator when the aircraft is in the normal operation mode, and to supply the coolant to both the main radiator and the sub-radiator when the aircraft is in the maximum output mode.

[0011] In one embodiment, the fuel cell system may further include a first coolant valve that either transmits the coolant to the main radiator or blocks the coolant from being transmitted to the main radiator, and a second coolant valve that either transmits the coolant to the sub-radiator or blocks the coolant from being transmitted to the sub-radiator.

[0012] In one embodiment, the control unit can switch the first cooling water valve to an open state and the second cooling water valve to a closed state when in the initial startup mode or the emergency operation mode.

[0013] In one embodiment, the control unit can switch the first cooling water valve to a closed state and the second cooling water valve to an open state when in the normal operating mode.

[0014] In one embodiment, the control unit can switch the first and second cooling water valves to an open state when the maximum output mode is active.

[0015] In one embodiment, the system further includes a cooling water pump for circulating the cooling water, and the control unit can control the rotational speed of the cooling water pump based on the external air temperature.

[0016] In one embodiment, the control unit can increase the rotation speed of the cooling water pump as the external air temperature increases, and decrease the rotation speed of the cooling water pump as the external air temperature decreases.

[0017] In one embodiment, the cooling water can be circulated through at least one of the main radiator and the sub-radiator, a temperature control valve, a stack cooling water pump, a bypass valve, and a fuel cell stack.

[0018] In one embodiment, the cooling water can be circulated through at least one of the main radiator and the sub-radiator, as well as through a stack cooling water pump, a fuel cell stack, and a flow path switching valve.

[0019] A control method for a fuel cell system according to one embodiment of the present invention may include the steps of: controlling the aircraft to release heat from the cooling water via the main radiator during initial startup; selecting one of the following operating modes for the aircraft: emergency operation mode, normal operation mode, and maximum power operation mode; and controlling the aircraft to release heat from the cooling water via at least one of the main radiator and sub-radiator according to the selected operating mode.

[0020] In one embodiment, the main radiator and the sub-radiator may be arranged such that the heat of the cooling water is released by the downdraft generated by the rotation of the propellers for the flight of the aircraft.

[0021] In one embodiment, the step of controlling the release of heat from the coolant through at least one of the main radiator and sub-radiators depending on the selected operating mode may include: controlling the release of heat from the coolant through the main radiator when the emergency operating mode is selected; controlling the release of heat from the coolant through the sub-radiator when the normal operating mode is selected; and controlling the release of heat from the coolant through the main radiator and sub-radiators when the maximum power operating mode is selected.

[0022] In one embodiment, the control method for the fuel cell system may further include the step of controlling the system to release heat from the cooling water through at least one of the main radiator and sub-radiator, depending on the selected operating mode, and then determining whether or not to terminate the operation of the aircraft.

[0023] In one embodiment, when it is determined that the operation of the aircraft has not ended, the step of selecting one of the emergency operation mode, normal operation mode, and maximum output operation mode of the aircraft can also be performed.

[0024] A method for controlling a fuel cell system according to an embodiment of the present invention includes a step of setting an initial rotational speed of a cooling water pump according to an operation mode of the aircraft, a step of determining whether a cooling water temperature is higher than a target temperature, a step of determining whether a difference between the cooling water temperature and the target temperature is within a preset temperature difference when the cooling water temperature is higher than the target temperature, and a step of increasing the rotational speed of the cooling water pump when the difference between the cooling water temperature and the target temperature is greater than the preset temperature difference.

[0025] In one embodiment, the method for controlling a fuel cell system may further include a step of decreasing the rotational speed of the cooling water pump when the cooling water temperature is lower than the target temperature and a difference between the cooling water temperature and the target temperature is greater than the preset temperature difference.

[0026] [[ID=**14**]]In one embodiment, the method for controlling a fuel cell system may further include a step of resetting the initial rotational speed of the cooling water pump based on the external air temperature.

[0027] In one embodiment, the step of resetting the initial rotational speed of the cooling water pump based on the external air temperature includes a step of maintaining the currently set initial rotational speed of the cooling water pump when the external air temperature is within the currently set applicable range, and a step of selecting an applicable range set according to the external air temperature and resetting the initial rotational speed of the cooling water pump according to the selected applicable range when the external air temperature deviates from the currently set applicable range.

Advantages of the Invention

[0028] This technology has the advantage that heat generated in a fuel cell system used in an aircraft can be efficiently released.

[0029] In addition, various effects directly or indirectly understood from this document can be provided.

Brief Description of the Drawings

[0030] [Figure 1] It is a diagram showing the configuration of an aircraft to which a fuel cell system according to an embodiment of the present invention is applied. [Figure 2] It is a diagram showing the configuration of a fuel cell system according to an embodiment of the present invention. [Figure 3] It is a diagram showing the configuration of a fuel cell system according to another embodiment of the present invention. [Figure 4] It is a diagram showing a flowchart for explaining the control operation of a fuel cell system according to an embodiment of the present invention. [Figure 5] It is a diagram showing a flowchart for explaining the control operation of a fuel cell system according to an embodiment of the present invention.

Modes for Carrying Out the Invention

[0031] Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. When attaching reference numerals to the components of each drawing, it should be noted that, for the same components, as long as they are shown on other drawings, they are given the same reference numerals as much as possible. In addition, when explaining the embodiments of the present invention, if it is determined that a detailed explanation of a related known configuration or function hinders the understanding of the embodiments of the present invention, the detailed explanation thereof will be omitted.

[0032] In describing the components of embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc., may be used. Such terms are used to distinguish a component from other components, and the terms do not limit the essence, order, or sequence of the component. Furthermore, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as those generally understood by a person of ordinary skill in the art to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0033] The embodiments of the present invention will be described in detail below with reference to Figures 1 to 5.

[0034] Figure 1 shows the configuration of an aircraft to which a fuel cell system according to one embodiment of the present invention is applied.

[0035] Referring to Figure 1, the aircraft to which the fuel cell system is applied is configured such that the radiators 110, 120, and 130 are arranged so that the downdraft (wind force) generated by the rotor rotation for the aircraft's flight passes through the radiators 110, 120, and 130 of the fuel cell system 100.

[0036] In this context, Figure 1 shows that radiators 110, 120, and 130 include a main radiator 110 and two sub-radiators 120 and 130, but this does not limit the number of main radiators 110 and sub-radiators 120 and 130.

[0037] The main radiator 110 may include a cooling fan 111.

[0038] In this case, the cooling fan 111 can be positioned perpendicular to the direction of the downdraft so that it does not rotate due to the downdraft generated by the propeller blades 200.

[0039] Furthermore, the main radiator 110 and the sub-radiators 120 and 130 may each include a stack radiator (STACK RAD) for releasing heat generated by the fuel cell stack 143 (Figure 2) and an electrical radiator (ELEC RAD) for releasing heat generated by the electrical components 152 (Figure 2).

[0040] As illustrated in Figure 1, a fuel cell system according to one embodiment of the present invention applied to an aircraft may include a main radiator 110 for releasing heat using the downdraft generated by the propeller blades for the aircraft's flight, and sub-radiators 120, 130.

[0041] Furthermore, the main radiator 110 and the sub-radiators 120 and 130 are distinguished by the presence or absence of a cooling fan 111.

[0042] In this case, the cooling fan 111 can be positioned on the main radiator 110 perpendicular to the direction of the downdraft so that it does not rotate due to the downdraft generated by the propeller blades.

[0043] Figure 2 shows the configuration of a fuel cell system according to one embodiment of the present invention.

[0044] Referring to Figure 2, the fuel cell system 100 may include a main radiator 110, a first sub-radiator 120, a second sub-radiator 130, a stack coolant pump 141, a bypass valve 142, a fuel cell stack 143, a heater 144, first to third stack coolant valves 145, 146, 147, a temperature control valve 148, an electrical coolant pump 151, electrical components 152, first to third electrical coolant valves 153, 154, 155, and a control unit 160.

[0045] The main radiator 110 may include a stack radiator, an electrical radiator, and a cooling fan 111.

[0046] The stack radiator included in the main radiator 110 can release the heat from the coolant flowing in through the first stack coolant valve 145 to the outside air.

[0047] The ELEC RAD electrical radiator included in the main radiator 110 can release the heat from the coolant flowing in via the first electrical coolant valve 153 to the outside air.

[0048] The cooling fan 111 can supply external air to the stack radiator and electrical radiator of the main radiator 110.

[0049] In this configuration, the cooling fan 111 can be rotated under the control of the control unit 160, and when rotating, it can supply external air to the main radiator 110.

[0050] The first sub-radiator 120 may include a stack radiator and an electric radiator.

[0051] The stack radiator of the first sub-radiator 120 can release the heat of the coolant flowing in through the second coolant valve 146 to the outside air.

[0052] The electrical radiator ELEC RAD of the first sub-radiator 120 can release the heat from the coolant flowing in through the second electrical coolant valve 154 to the outside air.

[0053] The second sub-radiator 130 can include a stack radiator (STACK RAD) and an electric radiator (ELEC RAD).

[0054] The stack radiator of the second sub-radiator 130 can release the heat from the coolant flowing in through the third coolant valve 147 to the outside air.

[0055] The electrical radiator ELEC RAD of the second sub-radiator 130 can release the heat of the coolant flowing in through the third electrical coolant valve 155 to the outside air.

[0056] In this process, the coolant that has passed through the stack radiator of the main radiator 110, the stack radiator of the first sub-radiator 120, and the stack radiator of the second sub-radiator 130 can flow into the temperature control valve 148.

[0057] Furthermore, the coolant that has passed through the ELEC RAD of the main radiator 110, the ELEC RAD of the first sub-radiator 120, and the ELEC RAD of the second sub-radiator 130 can be fed into the ELEC RAD of the electric coolant pump 141.

[0058] The temperature control valve 148 can receive both cooling water that has passed only through the fuel cell stack 143 and cooling water that has passed through the stack radiator (STACK RAD) of the fuel cell stack 143, the main radiator 110, and the first and second sub-radiators 120 and 130.

[0059] The temperature control valve 148, under the control of the control unit 160, can control the amount of coolant flowing in only through the fuel cell stack 143 and the amount of coolant passing through the stack radiators of the main radiator 110 and the first and second sub-radiators 120 and 130, thereby controlling the temperature of the coolant supplied to the stack coolant pump 141.

[0060] In other words, the temperature control valve 148 can supply the stack cooling water pump 141 with cooling water flowing in from a passage that passes only through the fuel cell stack 143, and cooling water flowing in from a passage that passes through the stack radiator STACK RAD of the fuel cell stack 143, the main radiator 110, and the first and second sub-radiators 120 and 130.

[0061] The stack cooling water pump 141 can circulate cooling water through the bypass valve 142, the fuel cell stack 143, the heater 144, the stack radiator STACK RAD of the main radiator 110, the stack radiators STACK RAD of the first and second sub-radiators 120 and 130, and the temperature control valve 148 in order to release the heat generated in the fuel cell stack 143.

[0062] The stack cooling water pump 141 can have its rotational speed controlled by the control unit 160, and the circulation speed of the cooling water can be increased or decreased based on the rotational speed controlled by the control unit 160.

[0063] The bypass valve 142 can transmit the cooling water supplied from the stack cooling water pump 141 to the fuel cell stack 143 or to the heater 144 under the control of the control unit 160.

[0064] When cooling water is supplied from the bypass valve 142, the heater 144 can be controlled by the control unit 160 to raise the temperature of the cooling water.

[0065] The first stack coolant valve 145 can, under the control of the control unit 160, either transmit coolant to the stack radiator of the main radiator 110 or block the transmission of coolant to the stack radiator of the main radiator 110.

[0066] The second stack coolant valve 146 can, under the control of the control unit 160, either transmit coolant to the stack radiator of the first sub-radiator 120 or block the transmission of coolant to the stack radiator of the first sub-radiator 120.

[0067] The third stack coolant valve 147 can, under the control of the control unit 160, either transmit coolant to the stack radiator of the second sub-radiator 130 or block the transmission of coolant to the stack radiator of the second sub-radiator 130.

[0068] The electrical coolant pump 151 can circulate the electrical radiator coolant from the main radiator 110 to dissipate the heat generated by the electrical components 152.

[0069] The rotational speed of the electrical cooling water pump 151 can be controlled by the control unit 160, and the rotational speed controlled by the control unit 160 can be used to increase or decrease the circulation speed of the cooling water used to dissipate the heat generated by the electrical components 152.

[0070] The first electrical coolant valve 153 can, under the control of the control unit 160, either transmit coolant to the electrical radiator ELEC RAD of the main radiator 110, or block the transmission of coolant to the electrical radiator ELEC RAD of the main radiator 110.

[0071] The second electrical coolant valve 154 can, under the control of the control unit 160, either transmit coolant to the electrical radiator ELEC RAD of the first sub-radiator 120, or block the transmission of coolant to the electrical radiator ELEC RAD of the first sub-radiator 120.

[0072] The third electrical coolant valve 155 can, under the control of the control unit 160, either transmit coolant to the electrical radiator ELEC RAD of the second sub-radiator 130, or block the transmission of coolant to the electrical radiator ELEC RAD of the second sub-radiator 130.

[0073] The electrical radiator ELEC RAD of the main radiator 110 can dissipate the heat of the coolant transmitted via the first electrical coolant valve 153 to the outside air.

[0074] The electrical radiator ELEC RAD of the first sub-radiator 120 can dissipate the heat of the coolant, which is transmitted via the second electrical coolant valve 154, to the outside air.

[0075] The electrical radiator ELEC RAD of the second sub-radiator 130 can discharge the heat of the coolant, which is transmitted via the third electrical coolant valve 155, to the outside air.

[0076] In this process, the coolant from which heat has been released by the ELEC RAD of the main radiator 110, the ELEC RAD of the first sub-radiator 120, and the ELEC RAD of the second sub-radiator 130 can flow into the ELEC RAD of the electric coolant pump 151.

[0077] The control unit 160 can control the first to third stack cooling water valves 145, 146, 147, the first to third electrical cooling water valves 153, 154, 155, the stack cooling water pump 141, and the electrical cooling water pump 151 based on the external air temperature and the aircraft's operating mode.

[0078] For example, the control unit 160 can control the rotation speed of the stack cooling water pump 141 and the electrical cooling water pump 151 based on the temperature of the outside air and the operating mode of the aircraft.

[0079] Furthermore, the control unit 160 can switch the first to third stack cooling water valves 145, 146, 147 and the first to third electrical cooling water valves 153, 154, 155, respectively, to an open or closed state based on the aircraft's operating mode.

[0080] More specifically, the control unit 160 determines the rotational speed range based on the aircraft's operating mode, and within the determined rotational speed range, it can increase or decrease the rotational speeds of the stack cooling water pump 141 and the electrical cooling water pump 151 respectively, according to the external air temperature.

[0081] The control unit 160 determines the rotation speed range based on the aircraft's operating mode, and within the determined rotation speed range, it can reduce the rotation speed of the stack cooling water pump 141 and the electrical cooling water pump 151 as the external air temperature decreases.

[0082] On the other hand, the control unit 160 determines the range of rotational speeds based on the aircraft's operating mode, and within the determined range of rotational speeds, it can increase the rotational speeds of the stack cooling water pump 141 and the electrical cooling water pump 151 as the external air temperature increases.

[0083] The aircraft's operating modes may include initial startup mode, emergency operation mode, normal operation mode, and maximum power mode.

[0084] The control unit 160 can switch the first stack cooling water valve 145 and the first electrical cooling water valve 153 to an open state and the second and third stack cooling water valves 146, 147 and the second and third electrical cooling water valves 154, 155 to a closed state when the aircraft's operating mode is the initial startup mode or emergency operation mode.

[0085] In this case, when coolant flows into the main radiator 110 via the first stack coolant valve 145 and the first electrical coolant valve 153, the control unit 160 can rotate the cooling fan 111. Therefore, the coolant can release heat through the stack radiator and electrical radiator of the main radiator 110.

[0086] When the aircraft's operating mode is in normal operation mode, the control unit 160 can switch the second and third stack cooling water valves 146, 147 and the second and third electrical cooling water valves 154, 155 to the open state, and switch the first stack cooling water valve 145 and the first electrical cooling water valve 153 to the closed state.

[0087] In this case, when coolant flows into the stack radiators and electrical radiators of the first and second sub-radiators 120 and 130 via the second and third stack coolant valves 146 and 147 and the second and third electrical coolant valves 154 and 155, the control unit 160 can stop the rotation of the cooling fan 111. Therefore, the coolant can release heat through the stack radiators and electrical radiators of the first and second sub-radiators 120 and 130.

[0088] The control unit 160 can switch the first to third stack cooling water valves 145, 146, 147 and the first to third electrical cooling water valves 153, 154, 155 to an open state when the aircraft's operating mode is the maximum output mode.

[0089] In this case, the control unit 160 can rotate the cooling fan 111, and the coolant can dissipate heat through the main radiator 110 and the stack radiators and electrical radiators of the first and second sub-radiators 120 and 130.

[0090] Figure 3 shows the configuration of a fuel cell system according to another embodiment of the present invention.

[0091] Referring to Figure 3, another embodiment of the present invention of a fuel cell system may include a main radiator 110, a first sub-radiator 120, a second sub-radiator 130, a stack cooling water pump 141, a fuel cell stack 143, a heater 144, first to third stack cooling water valves 145, 146, 147, a flow path switching valve 149, an electrical cooling water pump 151, electrical components 152, first to third electrical cooling water valves 153, 154, 155, and a control unit 160.

[0092] The main radiator 110, first sub-radiator 120, second sub-radiator 130, stack coolant pump 141, fuel cell stack 143, heater 144, first to third stack coolant valves 145, 146, 147, electrical coolant pump 151, electrical components 152, first to third electrical coolant valves 153, 154, 155 and control unit 160 shown in Figure 3 are the same as the main radiator 110, first sub-radiator 120, second sub-radiator 130, stack coolant pump 141, fuel cell stack 143, heater 144, first to third stack coolant valves 145, 146, 147, electrical coolant pump 151, electrical components 152, first to third electrical coolant valves 153, 154, 155 and control unit 160 shown in Figure 2. Since the radiator 120, second sub-radiator 130, stack coolant pump 141, fuel cell stack 143, heater 144, first to third stack coolant valves 145, 146, 147, electrical coolant pump 151, electrical components 152, first to third electrical coolant valves 153, 154, 155, and control unit 160 can be configured to perform the same operation, a detailed explanation of each configuration will be replaced by the explanation of each configuration in Figure 2.

[0093] The flow path switching valve 149 can perform the operations previously performed by the bypass valve 142 and temperature control valve 148 in Figure 2, under the control of the control unit 160.

[0094] For example, the flow path switching valve 149 can, under the control of the control unit 160, adjust the amount of coolant that has passed through the main radiator 110 and the first and second sub-radiators 120 and 130 and direct it to the stack coolant pump 141, adjust the amount of coolant that has passed through the heater 144 (which is turned off) without passing through the main radiator 110 and the first and second sub-radiators 120 and 130 and direct it to the stack coolant pump 141, and adjust the temperature of the coolant flowing into the stack coolant pump 141.

[0095] Furthermore, the flow path switching valve 149 can control the flow path of the cooling water so that the cooling water circulates through either the fuel cell stack 143 or the heater 144, under the control of the control unit 160.

[0096] Figures 4 and 5 are flowcharts illustrating the control operation of a fuel cell system according to one embodiment of the present invention.

[0097] In particular, Figure 4 is a diagram illustrating the operation of circulating cooling water through at least one of the main radiator 110, the first sub-radiator 120, and the second sub-radiator 130, depending on the aircraft's operating mode.

[0098] Referring to Figure 4, a cooling water circulation control method for a fuel cell system according to one embodiment of the present invention may include an initial start-up mode step (S1), a first valve control step (S2), an operation mode selection step (S3), an emergency operation mode application step (S4), a second valve control step (S5), a normal operation mode application step (S6), a third valve control step (S7), a maximum output operation mode application step (S8), a fourth valve control step (S9), and an operation termination determination step (S10).

[0099] The initial startup mode step (S1) can be the mode selected when the aircraft starts up.

[0100] In this process, the fuel cell stack 143 generates electrical energy and supplies it to the aircraft's rotor, thereby causing the rotor to rotate. The rotation of the rotor causes the propeller blades 200 to rotate, and the rotation of the propeller blades 200 creates a downdraft, allowing the aircraft to take off.

[0101] The first valve control step (S2) may include the steps of switching the first stack coolant valve 145 and the first electric coolant valve 153 to an open state so that coolant is supplied to the stack radiator STACK RAD and the electric radiator ELEC RAD of the main radiator 110 for stable thermal management of the fuel cell stack 143 and electric components 152 during the initial startup mode, and the steps of operating the cooling fan 111.

[0102] The operating mode selection step (S3) may include a step in which, after the initial startup mode step (S1), the aircraft operator or the aircraft's system selects one of the following operating modes: emergency operating mode (S4), normal operating mode (S6), and maximum power operating mode (S8).

[0103] If the emergency operation mode (S4) is selected in the operation mode selection step (S3), the second valve control step (S5) can be performed.

[0104] Furthermore, if the normal operating mode (S6) is selected in the operating mode selection step (S3), the third valve control step (S7) can be performed.

[0105] Furthermore, if the maximum output operating mode (S8) is selected in the operating mode selection step (S3), the fourth valve control step (S9) can be performed.

[0106] The second valve control step (S5) may include, in emergency operation mode, switching the first stack coolant valve 145 and the first electric coolant valve 153 to an open state so that coolant is supplied to the stack radiator STACK RAD and the electric radiator ELEC RAD of the main radiator 110 for stable thermal management of the fuel cell stack 143 and the electric components 152, and operating the cooling fan 111.

[0107] The third valve control step (S7) may include switching the second and third stack coolant valves 146, 147 and the second and third electric coolant valves 154, 155 to an open state so that coolant is supplied to the first and second sub-radiators 120, 130 when in normal operating mode. At this time, the stack radiators and electric radiators of the first and second sub-radiators 120, 130 can release the heat from the coolant using the downdraft caused by the rotation of the propeller blades 200.

[0108] The fourth valve control step (S9) may include the steps of switching the first to third stack coolant valves 145, 146, 147 and the first to third electrical coolant valves 153, 154, 155 to an open state so that coolant can be supplied to the main radiator 110 and the first and second sub-radiators 120, 130 when in maximum power operation mode, and operating the cooling fan 111.

[0109] The fourth valve control step (S9) can supply coolant to all radiators 110, 120, and 130 so that the heat from the fuel cell stack 143 and electrical components 152 can be released to the maximum extent during maximum power operation mode.

[0110] After one of the second to fourth valve control steps (S5, S7, S9) is performed, the operation termination determination step (S10) can be performed.

[0111] The step for determining whether operation can be terminated (S10) may include a step for determining whether the operation of the aircraft has been terminated.

[0112] If, for example, the operation of the aircraft is not terminated in the operation termination determination step (S10) (No), the process can be restarted from the operation mode selection step (S3).

[0113] On the other hand, if it is determined in the operation termination determination step (S10) that the operation of the aircraft has ended (Yes), the cooling water circulation control method for the fuel cell system according to one embodiment of the present invention can be terminated.

[0114] Figure 5 illustrates how to control the cooling water pump of the fuel cell system based on the aircraft's operating mode and the external air (outside air) temperature.

[0115] In this case, Figure 5 shows a method for controlling the circulation speed of the cooling water by controlling the rotation speed of the cooling water pump according to the aircraft's operating mode and ambient temperature.

[0116] The term "cooling water pump" may include the stack cooling water pump 141 and the electrical cooling water pump 151 shown in Figure 2.

[0117] [Table 1]

[0118] Table 1 can show the initial selection values ​​for the cooling water pump rotation speed based on ambient temperature and the aircraft's operating mode.

[0119] In this case, the rotational speeds of the stack cooling water pump 141 and the electrical cooling water pump 151 for each operating mode can be different from each other.

[0120] For example, if the ambient temperature Temp is lower than A1, the initial rotation speed of the cooling water pump can be set to B0 during initial startup or emergency operation mode, to C0 during normal operation mode, and to D0 during maximum output operation.

[0121] Furthermore, if the ambient temperature Temp is higher than A1 and lower than A2, the initial rotation speed of the cooling water pump can be set to B1 during initial startup or emergency operation mode, to C1 during normal operation mode, and to D1 during maximum output operation.

[0122] Furthermore, if the external temperature Temp is higher than An, the initial rotation speed of the cooling water pump can be set to the maximum value (Max) in initial startup, emergency operation mode, normal operation mode, and maximum output operation mode.

[0123] In this case, the higher the ambient temperature (Temp), the higher the initial rotation speed of the cooling water pump in each operating mode can be.

[0124] In other words, B1 can be a higher value than B0, C1 can be a higher value than C0, and D1 can be a higher value than D0.

[0125] Referring to Table 1 and Figure 5, a method for controlling the cooling water pump of a fuel cell system according to one embodiment of the present invention will be described as follows.

[0126] A cooling water pump control method for a fuel cell system according to one embodiment of the present invention may include an initial start mode or emergency operation mode selection step (S11), a normal operation mode selection step (S12), a maximum output mode selection step (S13), a cooling water pump rotation speed selection step (S14), a cooling water pump rotation speed input step (S15), a temperature comparison step (S16), a first temperature difference determination step (S17), a rotation speed increase step (S18), a second temperature difference determination step (S19), a rotation speed decrease step (S20), an ambient temperature applicable range change determination step (S21), and an applicable range selection step (S22).

[0127] One of the following operating modes can be selected: initial startup mode or emergency operation mode selection step (S11), normal operation mode selection step (S12), or maximum output mode selection step (S13).

[0128] The cooling water pump rotation speed selection step (S14) may include a step of selecting the initial rotation speed of the cooling water pump according to the selected operating mode.

[0129] Referring to Table 1, the cooling water pump rotation speed selection step (S14) can select one of the values ​​in Table 1 depending on the selected operating mode.

[0130] The cooling water pump rotation speed input step (S15) can be a step in which one value selected from the values ​​in Table 1 is set as the initial rotation speed of the cooling water pump.

[0131] In this case, once the initial rotational speed of the cooling water pump is set, the cooling water pump can operate at the set initial rotational speed.

[0132] The temperature comparison step (S16) may include a step to determine whether the measured cooling water temperature is higher than the target temperature.

[0133] In this case, the measured cooling water temperature can be the temperature of the cooling water flowing out to the fuel cell stack 143.

[0134] If the cooling water temperature measured in the temperature comparison step (S16) is not higher than the target temperature (No), the first temperature difference determination step (S17) can be performed.

[0135] On the other hand, if the cooling water temperature measured in the temperature comparison step (S16) is higher than the target temperature (Yes), the second temperature difference determination step (S19) can be performed.

[0136] The first temperature difference determination step (S17) may include a step of determining whether the difference between the measured cooling water temperature and the target temperature is within a preset temperature difference.

[0137] If the difference between the cooling water temperature measured in the first temperature difference determination step (S17) and the target temperature is within a preset temperature difference (Yes), then the ambient temperature applicable range change determination step (S21) can be performed.

[0138] On the other hand, if the difference between the cooling water temperature measured in the first temperature difference determination step (S17) and the target temperature is not within a preset temperature difference (No), the rotation speed reduction step (S18) can be performed.

[0139] The rotation speed reduction step (S18) may include a step of reducing the rotation speed of the cooling water pump. After the rotation speed reduction step (S18) is performed, the ambient temperature applicable range change determination step (S21) may be performed.

[0140] In other words, if the measured cooling water temperature is not higher than the target temperature, and the difference between the measured cooling water temperature and the target temperature is within a preset temperature difference, the ambient temperature range change determination step (S21) can be performed.

[0141] On the other hand, if the measured coolant temperature is not higher than the target temperature, and the difference between the measured coolant temperature and the target temperature is not within a preset temperature difference (i.e., it is greater than a preset temperature difference), the rotation speed of the coolant pump can be reduced, and then the ambient temperature applicable range change determination step (S21) can be performed.

[0142] The second temperature difference determination step (S19) may include a step of determining whether the difference between the measured ambient temperature and the target temperature, when the measured cooling water temperature is higher than the target temperature, is within a preset temperature difference.

[0143] If the difference between the cooling water temperature measured in the second temperature difference determination step (S19) and the target temperature is within a preset temperature difference (Yes), the ambient temperature applicable range change determination step (S21) can be performed.

[0144] On the other hand, if the difference between the cooling water temperature measured in the second temperature difference determination step (S19) and the target temperature is not within a preset temperature difference (No, it is greater than the preset temperature difference), the rotation speed increase step (S20) can be performed.

[0145] The rotational speed increase step (S20) may include increasing the rotational speed of the cooling water pump.

[0146] In other words, if the cooling water temperature is higher than the target temperature by a preset temperature difference, the rotation speed of the cooling water pump can be increased, and then the ambient temperature applicable range change determination step (S21) can be performed.

[0147] On the other hand, if the cooling water temperature is higher than the target temperature by less than a preset temperature difference, the ambient temperature range change determination step (S21) can be performed.

[0148] In other words, the cooling water pump control method for a fuel cell system according to one embodiment of the present invention can be configured such that, if the difference between the cooling water temperature measured after the initial rotation speed of the cooling water pump is set according to the operating mode is greater than or equal to a preset temperature difference, the rotation speed of the cooling water pump is increased or decreased, and then the ambient temperature applicable range determination step (S21) is performed.

[0149] Furthermore, in the cooling water pump control method for a fuel cell system according to one embodiment of the present invention, if the difference between the cooling water temperature measured after the initial rotation speed of the cooling water pump is set according to the operating mode and the target temperature is within a preset temperature difference, the rotation speed of the cooling water pump is not increased or decreased, and the ambient temperature applicable range determination step (S21) is performed.

[0150] The ambient temperature range determination step (S21) may include a step to determine whether the measured ambient temperature Temp has fallen outside the currently selected temperature range shown in Table 1.

[0151] If the ambient temperature measured in the ambient temperature applicability range determination step (S21) falls outside the selected temperature range (Yes), then the applicability range selection step (S22) can be performed to select a temperature range based on the measured ambient temperature.

[0152] On the other hand, if the ambient temperature measured in the ambient temperature applicability range determination step (S21) is not outside the selected temperature range (No), the step of maintaining the initial rotation speed of the cooling water pump (S15) can be performed.

[0153] As described above, the cooling water control method for a fuel cell system according to one embodiment of the present invention can improve the thermal management efficiency of the fuel cell system and minimize the power consumption required for thermal management by controlling the rotation speed of the cooling water pump based on the operating mode and ambient temperature.

[0154] The above description is merely illustrative of the technical concept of the present invention, and any person with ordinary skill in the art to which the present invention belongs can make various modifications and alterations without departing from the essential characteristics of the present invention.

[0155] Therefore, the embodiments disclosed in this invention are for illustrative purposes only, and not to limit the technical concept of the invention, and the scope of the technical concept of the invention is not limited by such embodiments. The scope of protection of this invention should be interpreted in accordance with the following claims, and all technical concepts within an equivalent scope should be interpreted as being included within the scope of the rights of this invention.

Claims

1. A propeller blade connected to a rotor for the flight of an aircraft, A main radiator and a sub-radiator are arranged to release heat from the cooling water by the downdraft generated by the rotation of the propeller blades, A fuel cell system comprising a control unit that controls the supply of the cooling water to at least one or more of the main radiator and sub-radiators based on the operating mode of the aircraft.

2. The operating mode of the aforementioned aircraft is: This includes initial startup mode, emergency operation mode, normal operation mode, and maximum output mode. The control unit, In the initial startup mode and the emergency operation mode, the system controls the supply of the cooling water to the main radiator. In the normal operating mode, the system controls the supply of the cooling water to the sub-radiator. The fuel cell system according to claim 1, characterized in that, when in the maximum output mode, the cooling water is controlled to be supplied to the main radiator and the sub-radiator.

3. A first coolant valve that either transmits the coolant to the main radiator or blocks the transmission of the coolant to the main radiator, The fuel cell system according to claim 2, further comprising a second coolant valve that transmits the coolant to the sub-radiator or blocks the transmission of the coolant to the sub-radiator.

4. The control unit, The fuel cell system according to claim 3, characterized in that when in the initial startup mode or the emergency operation mode, the first cooling water valve is switched to an open state and the second cooling water valve is switched to a closed state.

5. The control unit, The fuel cell system according to claim 3, characterized in that, when in the normal operating mode, the first cooling water valve is switched to a closed state and the second cooling water valve is switched to an open state.

6. The control unit, The fuel cell system according to claim 3, characterized in that when the maximum output mode is activated, the first and second cooling water valves are switched to an open state.

7. The system further includes a cooling water pump for circulating the aforementioned cooling water, The control unit, The fuel cell system according to claim 1, characterized in that the rotation speed of the cooling water pump is controlled based on the external air temperature.

8. The control unit, As the external air temperature increases, the rotation speed of the cooling water pump is increased. The fuel cell system according to claim 7, characterized in that the rotation speed of the cooling water pump is reduced as the external air temperature decreases.

9. The aforementioned cooling water is The fuel cell system according to claim 1, characterized in that at least one of the main radiator and the sub-radiator is circulated via a temperature control valve, a stack cooling water pump, a bypass valve, and a fuel cell stack.

10. The aforementioned cooling water is The fuel cell system according to claim 1, characterized in that at least one of the main radiator and the sub-radiator is circulated via a stack cooling water pump, a fuel cell stack, and a flow path switching valve.

11. The steps include controlling the release of heat from the cooling water via the main radiator during the initial startup of the aircraft, The steps include: selecting one of the following operating modes for the aircraft: emergency operation mode, normal operation mode, and maximum power operation mode; A method for controlling a fuel cell system, characterized by including the step of controlling the release of heat from the cooling water through at least one of the main radiator and sub-radiator, depending on the selected operating mode.

12. The main radiator and the sub-radiator are, A control method for a fuel cell system according to claim 11, characterized in that the cooling water is arranged such that the heat is released by the downdraft generated by the rotation of the propeller for the flight of the aircraft.

13. Depending on the selected operating mode, the step of controlling the release of heat from the coolant through at least one of the main radiator and sub-radiator is: When the emergency operation mode is selected, the process includes controlling the system so that the heat of the coolant is released through the main radiator, When the normal operating mode is selected, the process includes controlling the system so that the heat of the coolant is released through the sub-radiator, A method for controlling a fuel cell system according to claim 11, characterized in that when the maximum output operating mode is selected, the method includes the step of controlling the system so that the heat of the cooling water is released through the main radiator and the sub-radiator.

14. A control method for a fuel cell system according to claim 11, further comprising the step of controlling the system to release heat from the cooling water through at least one of the main radiator and sub-radiator according to the selected operating mode, and then determining whether or not to terminate the operation of the aircraft.

15. The step of determining whether or not the operation of the aforementioned aircraft can be terminated is: The control method for a fuel cell system according to claim 14, further characterized in that if it is determined that the operation of the aircraft has not ended, the step of selecting one of the operating modes of the aircraft, from emergency operation mode, normal operation mode, and maximum output operation mode, is performed.

16. The steps include: setting the initial rotation speed of the cooling water pump according to the operating mode of the aircraft; and determining whether the cooling water temperature is higher than the target temperature. If the cooling water temperature is higher than the target temperature, the step is to determine whether the difference between the cooling water temperature and the target temperature is within a predetermined temperature difference. A method for controlling a fuel cell system, characterized by including the step of increasing the rotation speed of the cooling water pump if the difference between the cooling water temperature and the target temperature is greater than the preset temperature difference.

17. A method for controlling a fuel cell system according to claim 16, further comprising the step of reducing the rotation speed of the cooling water pump when the cooling water temperature is lower than the target temperature and the difference between the cooling water temperature and the target temperature is greater than the preset temperature difference.

18. The control method for a fuel cell system according to claim 17, further comprising the step of resetting the initial rotation speed of the cooling water pump based on the external air temperature.

19. The step of resetting the initial rotation speed of the cooling water pump based on the external air temperature includes, if the external air temperature is within the currently set applicable range, the step of maintaining the currently set initial rotation speed of the cooling water pump. A control method for a fuel cell system according to claim 18, characterized in that, if the external air temperature deviates from the currently set applicable range, a set applicable range based on the external air temperature is selected, and the initial rotation speed of the cooling water pump is reset according to the selected applicable range.

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