Cooling structure of air cooler

Abstract

A structure for cooling an air cooler includes: a stack cooling line in which a stack coolant for cooling a fuel cell stack circulates; an electronic component cooling line in which an electronic component coolant for cooling the electronic component circulates; an air cooler disposed on the electronic component cooling line to cool air supplied to the cathode of the fuel cell stack; and a first valve connected to a front side of the air cooler to supply at least one of the stack coolant and the electronic component coolant to the air cooler. The structure for cooling the air cooler may include a bypass line connecting the electronic component cooling line upstream of the first valve to the electronic component cooling line downstream of the air cooler so that the electronic component coolant bypasses the air cooler.

Description

Technical Field

[0001] The present invention relates to a cooling structure of an air cooler capable of preventing an increase in ion conductivity of a stack coolant while cooling an air cooler for cooling air supplied to a fuel cell stack using at least one of a stack coolant and an electronic component coolant. Background Art

[0002] A fuel cell system is a power generation system that generates electric energy by an electrochemical reaction between hydrogen and oxygen using a fuel cell. The fuel cell system is applied to environmentally friendly vehicles such as electric vehicles or hybrid vehicles to supply the electric energy required to operate an electric motor.

[0003] The fuel cell system includes a fuel cell stack as a power generation assembly of unit fuel cells each including an air electrode and a fuel electrode, an air supply device for supplying air to the air electrode of the fuel cell, and a hydrogen supply device for supplying hydrogen to the fuel electrode of the fuel cell. The air supply device may include an air compressor for supplying compressed air to the fuel cell stack.

[0004] In a polymer fuel cell, the ion exchange membrane of the membrane-electrode assembly (MEA) requires an appropriate amount of moisture to function smoothly (i.e., consistently or efficiently). To this end, the air supply device of the fuel cell system includes a humidifier for humidifying the air supplied to the fuel cell by an air compressor. For example, the humidifier humidifies the dry air supplied by the compressor using the moisture contained in the high-temperature and high-humidity air (humid air) discharged from the air electrode of the fuel cell, and supplies the humidified air to the air electrode of the fuel cell.

[0005] The air, which may be overheated by the compressor, is introduced into the air cooler in order to be cooled before being supplied to the humidifier. The air cooler requires a refrigerant to cool the overheated air. Typically, the air cooler is cooled using additionally supplied external air, an electronic component coolant in a fuel cell system, or a stack coolant for cooling a fuel cell stack.

[0006] However, the temperature of the electronic component coolant is a temperature that converges to the temperature of the outside air. If only the electronic component coolant is used to cool the air cooler when the outside air temperature is low, water droplets will be introduced into the fuel cell stack, resulting in degradation of the durability of the fuel cell stack. In addition, using the electronic component coolant to cool the air cooler will result in insufficient cooling of the electronic components.

[0007] In addition, in a mode where the output of the fuel cell stack is high, the temperature of the stack coolant is relatively high. Therefore, if the air cooler is cooled using only the stack coolant, it may be difficult for the air cooler to cool the outside air to a desired temperature.

[0008] Both the stack coolant and the electronic component coolant may be used to cool the air cooler. However, in this case, since the electronic component coolant has a higher ionic conductivity than the stack coolant, the ionic conductivity of the coolant circulating through the stack cooling line increases.

[0009] The above information described in this Background section is provided only to enhance the understanding of the background of the present invention. Therefore, the Background section may contain information that does not constitute prior art known to a person of ordinary skill in the art. Summary of the invention

[0010] The present invention is directed to solving the above-mentioned problems associated with the prior art. An object of the present invention is to provide a cooling structure of an air cooler capable of preventing an increase in the ionic conductivity of a stack coolant during cooling of an air cooler for cooling air supplied to a fuel cell stack using at least one of a stack coolant and an electronic component coolant.

[0011] In one aspect, the present invention provides a structure for cooling an air cooler. The structure for cooling the air cooler includes: a stack cooling line configured to circulate a stack coolant for cooling a fuel cell stack therein; an electronic component cooling line configured to circulate an electronic component coolant for cooling electronic components therein; an air cooler configured on the electronic component cooling line to cool air supplied to a cathode of the fuel cell stack; and a first valve connected to the front side of the air cooler to supply at least one of the stack coolant and the electronic component coolant to the air cooler. The structure for cooling the air cooler includes a bypass line that connects the electronic component cooling line upstream of the first valve to the electronic component cooling line downstream of the air cooler so that the electronic component coolant bypasses the air cooler.

[0012] In one embodiment, the first valve may be disposed on a branch line connecting the air cooler to the front side of the fuel cell stack.

[0013] In another embodiment, the structure for cooling the air cooler may further include a second valve disposed on the bypass line, and a third valve disposed on a collecting line connecting the air cooler with a stack cooling line downstream of the fuel cell stack.

[0014] In yet another embodiment, when the output of the fuel cell stack is less than a predetermined output, the first port of the first valve connected to the stack cooling line may be fully opened, the second port of the first valve connected to the electronic component cooling line may be fully closed, and the second valve and the third valve may be opened.

[0015] In yet another embodiment, when the output of the fuel cell stack becomes equal to or greater than a predetermined output, the first port of the first valve connected to the stack cooling line may be gradually closed, the second port of the first valve connected to the electronic component cooling line may be gradually opened, and the second valve and the third valve may be gradually closed.

[0016] In yet another embodiment, the stack coolant and the electronic component coolant may flow into the air cooler through the first valve while the first port of the first valve is fully closed or the second port of the first valve is fully opened.

[0017] In another embodiment, when the output of the fuel cell stack is equal to or greater than a predetermined output, the first port of the first valve connected to the stack cooling line can be fully closed, the second port of the first valve connected to the electronic component cooling line can be fully opened, and in the state where the first port of the first valve is fully closed, the second valve and the third valve can be fully closed.

[0018] In yet another embodiment, when the first port of the first valve is completely closed, only the electronic component coolant can flow into the air cooler, and the electronic component coolant that has cooled the air cooler can circulate along the electronic component cooling line and can flow into the electronic component radiator arranged on the electronic component cooling line.

[0019] In yet another embodiment, the opening angles of the second valve and the third valve may correspond to the opening angle of the first port of the first valve.

[0020] In yet another embodiment, the structure for cooling the air cooler may further include a controller configured to control a first valve and a flow control valve configured on the stack cooling line, and the controller may control the first valve and the flow control valve based on the output of the fuel cell stack. When the electronic component coolant and the stack coolant flow into the air cooler simultaneously through the first valve, the controller may control the flow control valve so that the coolant circulates to the ion filter configured on the stack cooling line.

[0021] In another embodiment, when the opening of the first port of the first valve connected to the stack cooling line changes based on the output of the fuel cell stack, the controller may control the flow control valve based on the ionic conductivity of the coolant circulating through the stack cooling line so that the coolant circulates to the ion filter.

[0022] In yet another embodiment, when the first port of the first valve is closed from a fully open state and when the second port of the first valve connected to the electronic component cooling line is closed from a fully open state, the controller may control the flow control valve so that the coolant circulates to the ion filter within a predetermined period of time.

[0023] In still another embodiment, the predetermined time period may be a time period shorter than a time period taken for the first port of the first valve to be fully closed from a fully open state or a time period taken for the second port of the first valve to be fully closed from a fully open state.

[0024] In yet another embodiment, the structure for cooling the air cooler may further include a second valve disposed on the bypass line, and when the first valve is controlled to allow the electronic component coolant to flow into the air cooler, the second valve may be opened.

[0025] On the other hand, the present invention provides a structure for cooling an air cooler. The structure for cooling an air cooler includes: a stack cooling line configured to circulate a stack coolant for cooling a fuel cell stack; an electronic component cooling line configured to circulate an electronic component coolant for cooling electronic components; an air cooler configured on the electronic component cooling line to cool the air supplied to the cathode of the fuel cell stack; and a first valve connected to the front side of the air cooler to supply at least one of the stack coolant and the electronic component coolant to the air cooler. The first valve is controlled based on the output of the fuel cell stack. When the first valve is controlled, a flow control valve configured on the stack cooling line is controlled based on the ionic conductivity of the stack coolant, so that the stack coolant flows into an ion filter configured on the stack cooling line.

[0026] In one embodiment, the structure for cooling the air cooler may include a bypass line connecting the electronic component cooling line upstream of the first valve to the electronic component cooling line downstream of the air cooler so that the electronic component coolant bypasses the air cooler, and a second valve may be configured on the bypass line.

[0027] In another embodiment, the opening angle of the second valve may correspond to the opening angle of the first port of the first valve connected to the stack cooling line.

[0028] In yet another embodiment, when the first port of the first valve is closed from a fully open state and when the second port of the first valve connected to the electronic component cooling line is closed from a fully open state, the flow control valve arranged on the stack cooling line can be controlled so that the coolant flows into the ion filter within a predetermined period of time.

[0029] In yet another embodiment, when the output of the fuel cell stack is less than a predetermined output, the first port of the first valve connected to the stack cooling line may be fully opened, and the second port of the first valve connected to the electronic component cooling line may be fully closed.

[0030] In yet another embodiment, when the output of the fuel cell stack is equal to or greater than a predetermined output, the first valve may be controlled so that the first port of the first valve connected to the stack cooling line is fully closed and the second port of the first valve connected to the electronic component cooling line is fully opened.

[0031] Other aspects and embodiments of the invention are discussed herein.

[0032] It should be understood that the terms "vehicle" or "vehicle-like" or other similar terms used herein generally include motor vehicles. Thus, these terms may cover passenger vehicles including sport utility vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft including various boats and ships, aircraft, etc. These terms may also include hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels obtained from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle having two or more sources of power, such as a vehicle having both gasoline power and electric power.

[0033] The above and other features of the invention are discussed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above and other features of the invention are described in detail with reference to certain embodiments of the invention shown in the accompanying drawings, which are given hereinafter by way of illustration only and therefore do not limit the invention, and in which:

[0035] Figure 1 is a diagram showing a cooling structure of an air cooler according to an embodiment of the present invention;

[0036] Figure 2 is a block diagram for illustrating a control strategy of a valve according to an embodiment of the present invention;

[0037] Figure 3 to Figure 5 is a diagram for explaining a control strategy of a first valve according to an output of a fuel cell stack according to an embodiment of the present invention;

[0038] Figure 6 is a flowchart illustrating a method for controlling a cooling structure of an air cooler according to an embodiment of the present invention; and

[0039] Figure 7 is a diagram showing a cooling structure of an air cooler according to another embodiment of the present invention.

[0040] It should be understood that the accompanying drawings are not necessarily drawn to scale, but rather present somewhat simplified representations of various features illustrating the basic principles of the invention. The specific design features of the present invention disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes, will be determined in part by the specific intended application and use environment.

[0041] In the drawings, like reference numbers refer to the same or equivalent parts of the present invention throughout the several views. DETAILED DESCRIPTION

[0042] The advantages and features of the present invention and their implementation methods should be more clearly understood through the embodiments described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in a variety of different forms and should not be construed as being limited to the embodiments described herein. On the contrary, these embodiments are provided to make this disclosure detailed and complete and to fully convey the scope of the present invention to those of ordinary skill in the art. The present invention is limited only by the scope of the claims. Throughout the specification, the same reference numerals represent the same components.

[0043] The terms “…section”, “…unit” and “…module” used in this specification mean a unit for processing at least one function or operation and can be implemented as a hardware component, a software component, or a combination of a hardware component and a software component.

[0044] In addition, in the following description, the terms "first" and "second" are used only to avoid confusion about the designated components, and do not indicate the order or importance of the components or the relationship between the components. When a component, device, element, etc. of the present invention is described as having a purpose or performing an operation, function, etc., the component, device or element should be considered herein as "configured to" meet the purpose or perform the operation or function.

[0045] The detailed description is an illustration of the present invention. The following description is intended to illustrate and explain embodiments of the present invention, and the present invention may be used in various other combinations, modifications and environments. In other words, the present invention may be changed or modified within the scope of the inventive concept disclosed herein, the scope of the equivalents of the present invention and / or the technology or knowledge in the art. The described embodiments illustrate the state of the technical ideas for implementing the present invention, and various changes may be made to it according to the needs of the specific application and use of the present invention. Therefore, the following detailed description is not intended to limit the present invention to the embodiments disclosed herein. Moreover, the appended claims should be interpreted as covering such other embodiments.

[0046] Figure 1 is a diagram showing a cooling structure of an air cooler according to an embodiment of the present invention. Figure 2 is a block diagram for explaining a control strategy of a valve according to an embodiment of the present invention.

[0047] Reference Figure 1 and Figure 2The cooling structure of the air cooler may be a structure capable of cooling the air cooler 200 for cooling the air supplied to the fuel cell stack 10 using any one of the coolant circulating through the stack cooling line 5 and the coolant circulating through the electronic component cooling line 6. The stack cooling line 5 may be a line through which the stack coolant flows for cooling the fuel cell stack 10. The electronic component cooling line 6 may be a line through which the electronic component coolant flows for cooling the electronic components 230, 240, 250, 260, and 270.

[0048] The fuel cell stack 10 , the radiator 20 , the flow control valve 30 , the cathode oxygen consumption (COD) heater 40 , the heater core 50 , the coolant pump 60 , and the ion filter 70 may be disposed on the stack cooling line 5 .

[0049] The fuel cell stack 10 can generate electricity by a chemical reaction between the supplied air and hydrogen. The fuel cell stack 10 can be a polymer electrolyte membrane fuel cell (PEMFC) using a polymer membrane that can allow hydrogen ions to pass through as an electrolyte. In other words, the fuel cell stack 10 may include a polymer electrolyte membrane or a proton exchange membrane (PEM). The power generation efficiency of the fuel cell stack 10 may vary depending on the moisture supplied to the polymer electrolyte membrane. The fuel cell stack 10 may include a fuel electrode (anode) and an air electrode (cathode). Reformed hydrogen may be supplied to the fuel electrode of the fuel cell stack 10, and air (oxygen) may be supplied to the air electrode of the fuel cell stack 10. In order to dissipate the heat generated as a byproduct of the chemical reaction between hydrogen and oxygen occurring in the fuel cell stack 10, a coolant may be introduced into the fuel cell stack 10. While the fuel cell stack 10 generates electricity by an electrochemical reaction between hydrogen and air, high temperature and high humidity air may be discharged from the air electrode of the fuel cell stack 10.

[0050] The radiator 20 may cool the coolant whose temperature rises after the chemical reaction in the fuel cell stack 10. The cooled coolant may flow to the flow control valve 30. The reservoir 25 may adjust the pressure of the coolant of the fuel cell thermal management system. The reservoir 25 may suppress the occurrence of cavitation in the coolant pump 60, and may adjust the pressure of the coolant to prevent the pressure of the fuel cell stack 10 from exceeding a predetermined internal pressure. Cavitation is a phenomenon in which impact noise or erosion occurs when bubbles generated in a high-speed low-pressure portion in the coolant pump 60 move to a high-pressure portion and disappear. In addition, the reservoir 25 may store coolant to adjust the pressure of the coolant. The reservoir 25 may be configured downstream of the fuel cell stack 10 and between the fuel cell stack 10 and the front side of the coolant pump 60. The coolant discharged from the fuel cell stack 10 may be stored in the reservoir 25. The coolant discharged from the reservoir 25 may flow into the coolant pump 60. The reservoir 25 may be configured in parallel with the radiator 20.

[0051] The flow control valve 30 may control the path and flow rate of the coolant flowing through the stack cooling line 5. The flow control valve 30 may be a five-way valve. However, unlike the above example, the valve constituting the fuel cell thermal management system may include at least one of a four-way valve and a three-way valve. The coolant may flow from the fuel cell stack 10, the radiator 20, the COD heater 40, and the ion filter 70 to the flow control valve 30. The coolant may flow from the flow control valve 30 to the coolant pump 60. The flow control valve 30 may be controlled according to an opening strategy that varies depending on the output of the fuel cell stack 10 or the operating mode of the thermal management system.

[0052] The COD heater 40 may consume the power generated by the fuel cell stack 10 in order to increase the temperature of the coolant when it is necessary to increase the temperature of the coolant or to reduce the voltage of the fuel cell stack 10. Specifically, the COD heater 40 may operate to consume the power generated by the fuel cell stack 10 when the fuel cell system is turned on or off and when regenerative braking is continuously performed in a state where the state of charge (SOC) of the high-voltage battery is sufficient.

[0053] The heater core 50 may be a component that performs vehicle interior heating through heat exchange between the coolant whose temperature has been raised by the COD heater 40 and the outside air. During interior heating, the coolant whose temperature has been raised by the COD heater 40 may flow into the heater core 50 to heat the heater core 50, and through heat exchange between the compressed outside air and the heated coolant in the heater core 50, high-temperature air may flow into the interior space of the vehicle.

[0054] The coolant pump 60 may supply the coolant delivered from the flow control valve 30 to the fuel cell stack 10 , the COD heater 40 , or the ion filter 70 .

[0055] The ion filter 70 may remove ions contained in the coolant. The ion filter 70 may remove ions contained in the coolant provided by the coolant pump 60 , and the coolant from which ions have been removed may be delivered to the flow control valve 30 .

[0056] The air cooler 200 , the electronic component radiator 210 , the electronic component coolant pump 220 , the electronic components 230 , 240 , 250 , 260 , and 270 , and the air compressor 280 may be disposed on the electronic component cooling line 6 .

[0057] The air cooler 200 may perform heat exchange between high temperature air and a refrigerant to cool the high temperature air. In other words, the air cooler 200 may cool the air supplied to the cathode of the fuel cell stack 10. The refrigerant may be a coolant. In one example, the coolant used as the refrigerant may include at least one of a stack coolant for cooling the fuel cell stack 10 and an electronic component coolant for cooling the electronic components 230, 240, 250, 260, and 270. The air cooled by the coolant may be supplied to the humidifier 400. The temperature of the air supplied from the air cooler 200 to the humidifier 400 may vary according to the temperature of the coolant supplied to the air cooler 200.

[0058] The electronic component heat sink 210 may cool the coolant whose temperature has been increased in the process of cooling the electronic components 230, 240, 250, 260, and 270. The coolant cooled by the electronic component heat sink 210 may be supplied to the electronic component coolant pump 220. The electronic component coolant pump 220 may supply the cooled coolant to the electronic components 230, 240, 250, 260, and 270.

[0059] The electronic components 230 , 240 , 250 , 260 , and 270 may include a converter 230 , an external power supply unit 240 , a power distribution unit 250 , an inverter 260 , and a motor 270 .

[0060] The converter 230 may be an integrated DC-DC converter in which a bidirectional high-voltage DC-DC converter (BHDC) provided between the fuel cell stack 10 and the high-voltage battery installed in the vehicle and a low-voltage DC-DC converter (LDC) that converts a DC high voltage supplied by the high-voltage battery into a DC low voltage are integrated with each other. The coolant supplied from the electronic component coolant pump 220 may cool the converter 230, and the coolant that has cooled the converter 230 may flow into the external power supply unit 240.

[0061] The external power supply unit 240 may include a component that supplies power of a high voltage battery installed in the vehicle to the outside (Vehicle to Load (V2L)). The coolant that has cooled the external power supply unit 240 may flow into the air compressor 280 .

[0062] The air compressor 280 may compress external air and may supply the compressed external air to the air cooler 200. The external air may remove foreign matter through the air filter 300 and then may flow into the air compressor 280. Since the air compressor 280 compresses the air, the pressure and temperature of the air may increase, and the high-temperature and high-pressure air may be supplied to the air cooler 200.

[0063] A power distribution unit (PDU) 250 may be a device that controls electric power. The coolant supplied from the electronic component coolant pump 220 may cool the power distribution unit 250. The coolant that has cooled the power distribution unit 250 may flow into the inverter 260.

[0064] The inverter 260 may be a component that converts current applied or provided to the motor 270 that provides driving force required to drive the vehicle. The coolant that has cooled the inverter 260 may flow into the motor 270.

[0065] The motor 270 may provide driving force required to drive the vehicle. The coolant that has cooled the inverter 260 may cool the motor 270 or provide an oil cooler for cooling oil of the motor 270. The coolant that has cooled the motor 270 or the oil cooler may flow into the electronic component radiator 210.

[0066] The humidifier 400 may humidify the air supplied from the air cooler 200. The humidifier 400 may then supply the humidified air to the cathode (air electrode) of the fuel cell stack 10. For example, the humidifier 400 may be a membrane humidifier, but the present invention is not limited to any particular type of humidifier 400. The dry air cooled by the air cooler 200 may flow into the fuel cell stack 10 through the humidifier 400.

[0067] The first valve 100 for controlling the coolant flowing into the air cooler 200 may be connected to the front side (e.g., upstream) of the fuel cell stack 10. Specifically, the first valve 100 may be configured on the branch line 7 connecting the air cooler 200 to the front side of the fuel cell stack 10. In addition, the first valve 100 may be connected to the electronic component cooling line 6. The coolant of the cooled air compressor 280 may flow into the first valve 100 before flowing into the air cooler 200. In other words, the first valve 100 may be configured on the front side (e.g., upstream) of the air cooler 200. For example, the first valve 100 may be a three-way valve. The first valve 100 may supply at least one of the stack coolant flowing in from the stack cooling line 5 and the electronic component coolant flowing in from the electronic component cooling line 6 to the air cooler 200.

[0068] The first valve 100 may include a first port connected to the stack cooling line 5, a second port connected to the electronic component cooling line 6, and a third port for discharging the coolant to the air cooler 200. Specifically, the stack coolant supplied from the stack cooling line 5 may flow into the first port, and the coolant of the cooled air compressor 280 may flow into the second port. For example, the opening of the first port and the second port may be adjusted by controlling the opening of the first valve 100. The third port may always be maintained in an open state. Therefore, the first valve 100 may supply at least one of the stack coolant flowing into the first port and the electronic component coolant flowing into the second port to the air cooler 200.

[0069] The cooling structure of the air cooler may include a bypass line 8 for diverting the coolant of the cooled air compressor 280 to the electronic component radiator 210. The bypass line 8 may be branched from the line between the air compressor 280 and the first valve 100, and may be connected to the rear side (e.g., downstream) of the air cooler 200. The bypass line 8 may connect the electronic component cooling line 6 upstream of the first valve 100 to the electronic component cooling line 6 downstream of the air cooler 200. Therefore, when the second port of the first valve 100 is completely closed, the coolant of the cooled air compressor 280 may not circulate toward the air cooler 200, but may circulate along the bypass line 8 and flow into the electronic component radiator 210. The second valve 110 may be disposed on the bypass line 8. The second valve 110 may not be an on / off valve, but may be a two-way valve that gradually opens or closes the bypass line 8. Even if the electronic component coolant having cooled the air compressor 280 is not introduced into the air cooler 200 through the first valve 100, the electronic component coolant may circulate through the bypass line 8. Therefore, the electronic components 230, 240, 250, 260, and 270 may be continuously cooled.

[0070] The coolant discharged from the air cooler 200 may circulate along the electronic component cooling line 6. The collecting line 9 branched from the electronic component cooling line 6 may be connected to the downstream of the air cooler 200. The collecting line 9 may branch from the electronic component cooling line 6 and may be connected to the stack cooling line 5. Specifically, the collecting line 9 may branch from the electronic component cooling line 6 downstream of the air cooler 200 and may be connected to the stack cooling line 5 downstream of the fuel cell stack 10. The coolant circulating through the collecting line 9 may be a stack coolant or a mixture of a stack coolant and an electronic component coolant. Therefore, the stack coolant and the electronic component coolant may be coolants composed of the same components. The coolant circulating through the collecting line 9 may flow into the stack cooling line 5 downstream of the fuel cell stack 10, and then may flow into the radiator 20. The third valve 120 may be configured on the collecting line 9. The third valve 120 may not be an on / off valve, but may be a two-way valve that gradually opens or closes the collecting line 9. When only the electronic component coolant flows into the air cooler 200 , the third valve 120 is closed, thereby preventing the electronic component coolant from flowing into the stack cooling line 5 to the greatest extent.

[0071] The controller 500 may control the flow control valve 30, the first valve 100, the second valve 110, and the third valve 120 based on the output of the fuel cell stack 10 and the ionic conductivity of the coolant circulating through the stack cooling line 5. The opening angle or degree of the second valve 110 and the third valve 120 may correspond to the opening angle or degree of the first port of the first valve 100. In other words, when the first port of the first valve 100 is in a fully open state, the second valve 110 and the third valve 120 may be in a fully open state, and when the first port of the first valve 100 is in a fully closed state, the second valve 110 and the third valve 120 may be in a fully closed state. In addition, as the first port of the first valve 100 is gradually closed, the second valve 110 and the third valve 120 may be closed to the same extent as the first port of the first valve 100, and as the first port of the first valve 100 is gradually opened, the second valve 110 and the third valve 120 may be opened to the same extent as the first port of the first valve 100.

[0072] The controller 500 may control the first valve 100 based on whether the output of the fuel cell stack 10 is equal to or greater than a predetermined output. The fuel cell thermal management system may control the flow path of the coolant differently according to the normal output mode or the high output mode of the fuel cell stack 10. The predetermined output may be a reference for determining whether the fuel cell stack 10 is in the high output mode. When the output of the fuel cell stack 10 is equal to or greater than the predetermined output, the maximum cooling of the air cooler 200 is required, and the controller 500 may control the first valve 100 to allow the electronic component coolant to flow into the air cooler 200. When the output of the fuel cell stack 10 is less than the predetermined output, if the relatively low temperature electronic component coolant flows into the air cooler 200, the air supplied to the fuel cell stack 10 may be overcooled. Therefore, droplets may be introduced into the fuel cell stack 10, thereby deteriorating the durability of the fuel cell stack 10. Therefore, in order to prevent overcooling of the air cooler 200, the controller 500 may control the first valve 100 so that only the stack coolant flows into the air cooler 200.

[0073] When both the electronic component coolant and the stack coolant flow into the air cooler 200, the controller 500 may measure the ionic conductivity of the coolant circulating through the stack cooling line 5. When both the electronic component coolant and the stack coolant flow into the air cooler 200, the electronic component coolant may flow into the stack cooling line 5 through the collecting line 9. The electronic component coolant may have a higher ionic conductivity than the stack coolant. Therefore, as the electronic component coolant flows into the stack cooling line 5, a problem of increased ionic conductivity of the coolant circulating through the stack cooling line 5 may occur. Therefore, the controller 500 may control the flow control valve 30 based on the ionic conductivity so that the coolant flows into the ion filter 70. When the fuel cell stack 10 is in high output mode, the electronic component coolant may flow into the stack cooling line 5. When the fuel cell stack 10 is in high output mode, the controller 500 may control the flow control valve 30 so that the coolant temporarily flows into the ion filter 70.

[0074] According to an aspect of the present invention, since the temperature of the coolant supplied to the air cooler 200 by the first valve 100 is controlled in a wide range, the temperature of the air supplied from the air cooler 200 to the humidifier 400 can be controlled in a wide range. Therefore, the temperature of the air supplied to the humidifier 400 can be actively controlled, so that the humidification performance of the humidifier 400 can be improved.

[0075] According to an aspect of the present invention, by preventing the temperature of air flowing into the fuel cell stack 10 from being excessively reduced or increased, stable performance of the fuel cell stack 10 can be ensured, and the durability of the fuel cell stack 10 can be improved.

[0076] According to one aspect of the present invention, in normal mode, a relatively high temperature stack coolant may be used to adjust the temperature of the air cooler 200 to prevent droplets from flowing into the fuel cell stack 10. In high output mode, a relatively low temperature electronic component coolant may be used to achieve maximum cooling of the air cooler 200.

[0077] Figure 3 to Figure 5 is a diagram for explaining a control strategy of a first valve according to an output of a fuel cell stack according to an embodiment of the present invention. Figure 3 is a diagram showing a condition in which only the stack coolant is introduced into the air cooler through the first valve when the output of the fuel cell stack is less than a predetermined output.

[0078] Figure 4 is a diagram showing a condition in which both the stack coolant and the electronic component coolant are introduced into the air cooler through the first valve when the output of the fuel cell stack is equal to or greater than a predetermined output. Figure 5 is a diagram showing a condition in which only the electronic component coolant is introduced into the air cooler through the first valve when the output of the fuel cell stack is equal to or greater than a predetermined output.

[0079] Reference Figure 2 and Figure 3 , when the output of the fuel cell stack 10 is less than the predetermined output, the controller 500 may fully open the first port of the first valve 100 connected to the stack cooling line 5. When the vehicle is in a normal driving condition, the output of the fuel cell stack 10 is less than the predetermined output. In this case, the first port of the first valve 100 may be maintained in an open state. In addition, the second port of the first valve 100 connected to the electronic component cooling line 6 may be in a fully closed state, and the second valve 110 and the third valve 120 may be in a fully open state so as to correspond to the first port of the first valve 100. Therefore, only the stack coolant may be supplied to the air cooler 200, and the stack coolant that has cooled the air cooler 200 may circulate to the stack cooling line 5 through the collecting line 9. The electronic component coolant that has cooled the electronic components 230, 240, 250, 260 and 270 may circulate along the bypass line 8 and may flow into the electronic component radiator 210. Since the electronic component coolant does not flow into the stack cooling line 5 , the controller 500 may not need to control the flow control valve 30 to allow the coolant to flow into the ion filter 70 .

[0080] Reference Figure 2 and Figure 4 , when the output of the fuel cell stack 10 is equal to or greater than the predetermined output, the controller 500 may control the first valve 100 so that the first port of the first valve 100 connected to the stack cooling line 5 is completely closed. In this case, the first port of the first valve 100 may be gradually closed, and the second port of the first valve 100 may be gradually opened. The second valve 110 and the third valve 120 may be gradually closed in the same manner as the opening strategy of the first port of the first valve 100.

[0081] When the first port of the first valve 100, the second valve 110, and the third valve 120 are gradually closed, both the stack coolant and the electronic component coolant may flow into the air cooler 200. The stack coolant may flow into the first port of the first valve 100 through the branch line 7, and may flow into the air cooler 200 through the first port of the opened first valve 100. The electronic component coolant of the cooled air compressor 280 may flow into the second port of the first valve 100, and may flow into the air cooler 200 through the second port of the first valve 100. As the second valve 110 is gradually closed, the coolant of the cooled air cooler 200 may be discharged to the collecting line 9 and the electronic component cooling line 6. In addition, as the third valve 120 is gradually closed, the electronic component coolant may also circulate through the bypass line 8. When both the stack coolant and the electronic component coolant flow into the air cooler 200, the third valve 120 is also in a partially open state, so the electronic component coolant flows into the stack cooling line 5. In this case, the controller 500 may control the flow control valve 30 so that the coolant circulating through the stack cooling line 5 flows into the ion filter 70 , thereby appropriately controlling the ion conductivity of the coolant.

[0082] As the electronic component coolant flows into the stack cooling line 5 through the collecting line 9, the ionic conductivity of the coolant circulating through the stack cooling line 5 may increase. The controller 500 may control the flow control valve 30 based on the ionic conductivity of the coolant acquired from the ionic conductivity sensor so that the coolant flows into the ion filter 70. When the opening of the first valve 100 changes, the controller 500 may control the flow control valve 30 based on the ionic conductivity of the coolant circulating through the stack cooling line 5 so that the coolant circulates to the ion filter 70. The case where the opening of the first valve 100 changes may correspond to the case where the first port of the first valve 100 is closed from a fully open state and the case where the second port of the first valve 100 is closed from a fully open state. In other words, when the first port of the first valve 100 is maintained in a fully open state and when the first port of the first valve 100 is maintained in a fully closed state, the controller 500 may determine that it is not necessary to remove the ions contained in the coolant circulating through the stack cooling line 5. In addition, when the opening of the first valve 100 changes, if the ion conductivity is less than the threshold value, the controller 500 may not control the flow control valve 30 to circulate the coolant to the ion filter 70. When the opening of the first valve 100 changes and when the ion conductivity is equal to or greater than the threshold value, the controller 500 may control the flow control valve 30 so that the coolant circulates to the ion filter 70. In this case, the controller 500 may control the flow control valve 30 so that the coolant circulates to the ion filter 70 for a predetermined period of time. The predetermined period of time may be defined as a period of time shorter than the period of time taken for the first port of the first valve 100 to be completely closed from a fully open state or the period of time taken for the second port of the first valve 100 to be completely closed from a fully open state. However, the predetermined period of time may be a period of time that can be changed by the designer.

[0083] Reference Figure 2 and Figure 5 , when the output of the fuel cell stack 10 is equal to or greater than the predetermined output, the opening degree of the first valve 100 may be gradually changed so that the first port of the first valve 100 is completely closed, and the second port of the first valve 100 is completely opened. In this case, the second valve 110 and the third valve 120 may be completely closed in the same manner as the opening strategy of the first port of the first valve 100. Therefore, only the low-temperature electronic component coolant of the cooled air compressor 280 may flow into the air cooler 200, and the stack coolant may not flow into the air cooler 200. Since the third valve 120 is in a completely closed state, the electronic component coolant of the cooled air compressor 280 may circulate only to the air cooler 200. Since the second valve 110 is in a completely closed state, the electronic component coolant of the cooled air cooler 200 may circulate along the electronic component cooling line 6.

[0084] During the period when the first port of the first valve 100 is maintained in the fully closed state, the controller 500 may determine that there is no need to flow the coolant into the ion filter 70. Since the second valve 110 is in the fully closed state, the electronic component coolant does not flow into the stack cooling line 5 through the collecting line 9. Since there is no possibility that the ion conductivity of the coolant circulating through the stack cooling line 5 is increased due to the inflow of the electronic component coolant, the controller 500 may not control the flow control valve 30.

[0085] Unlike the above example, the flow control valve 30 may be controlled according to a control strategy of a fuel cell thermal management system. One aspect of the present invention describes controlling the first valve 100 and the flow control valve 30 based on the output of the fuel cell stack 10 and the ionic conductivity of the coolant circulating through the stack cooling line 5.

[0086] According to an aspect of the present invention, when electronic component coolant flows into the stack cooling line 5, the controller 500 may control the flow control valve 30 to circulate the coolant to the ion filter 70, thereby preventing the ion conductivity of the coolant circulating through the stack cooling line 5 from increasing.

[0087] According to one aspect of the present invention, when the cooling performance of the air cooler 200 needs to be ensured due to the high output mode of the fuel cell stack 10, only the electronic component coolant that has cooled the air compressor 280 flows into the air cooler 200 through the first valve 100, thereby maximally cooling the air cooler 200.

[0088] According to one aspect of the present invention, the coolant discharged from the air cooler 200 circulates along the electronic component cooling line 6, and can prevent the electronic component coolant from flowing into the stack cooling line 5 through the collecting line 9 branched from the electronic component cooling line 6 and the second valve 120 configured on the collecting line 9 to the greatest extent.

[0089] Figure 6 is a flowchart illustrating a method of controlling a cooling structure of an air cooler according to an embodiment of the present invention.

[0090] Reference Figure 1 , Figure 2 and Figure 6 , the controller 500 may monitor whether the fuel cell stack 10 is operated in the high output mode. When the fuel cell stack 10 is operated in the high output mode, the temperature of the stack coolant circulating through the stack cooling line 5 may be very high. When the high-temperature stack coolant is used to cool the air cooler 200, the air cooler 200 may have difficulty in lowering the temperature of the air supplied to the fuel cell stack 10 to a desired temperature due to relatively low cooling efficiency (S100).

[0091] When the fuel cell stack 10 is in the normal mode instead of the high output mode, the temperature of the stack coolant circulating through the stack cooling line 5 may be lower than the temperature of the stack coolant when the fuel cell stack 10 is in the high output mode. Therefore, even if the stack coolant cooling air cooler 200 is used, the air supplied to the fuel cell stack 10 may be cooled to a desired temperature. The controller 500 may maintain the first port of the first valve 100 connected to the stack cooling line 5 in a fully open state. Since the first port of the first valve 100 is maintained in a fully open state, the second valve 110 and the third valve 120 may also be maintained in a fully open state (S200).

[0092] When the fuel cell stack 10 is in the high output mode, the controller 500 may control the first valve 100 so that the second port of the first valve 100 connected to the electronic component cooling line 6 is fully opened, so that the relatively low temperature electronic component coolant flows into the air cooler 200. As the second port of the first valve 100 is gradually opened, the second valve 110 and the third valve 120 may be gradually closed (S300).

[0093] When the opening degree of the first valve 100 changes, the controller 500 may measure the ionic conductivity of the coolant circulating through the stack cooling line 5. The ionic conductivity may be monitored at any time by an ionic conductivity sensor disposed on the stack cooling line 5 (S400).

[0094] When the ion conductivity of the coolant circulating through the stack cooling line 5 is less than the threshold value, even if the opening degree of the first valve 100 is changed, the coolant circulating through the stack cooling line 5 may not flow into the ion filter 70. When the ion conductivity is less than the threshold value, the coolant may not flow into the ion filter 70 to ensure the durability of the ion filter 70 (S500).

[0095] When the ion conductivity of the coolant circulating through the stack cooling line 5 is equal to or greater than the threshold value, the controller 500 may control the flow control valve 30 so that the coolant flows into the ion filter 70. The flow control valve 30 may be a valve capable of changing the path of the coolant to the ion filter 70. The controller 500 may control the flow control valve 30 so that the coolant flows into the ion filter 70 only during a predetermined period of time (S600).

[0096] The controller 500 can continuously monitor the output of the fuel cell stack 10. When the high output mode of the fuel cell stack 10 is not terminated, the second port of the first valve 100 can be maintained in a fully open state. Since the state in which the second port of the first valve 100 is maintained in a fully open state is a state in which the opening of the first valve 100 does not change, the controller 500 can control the flow control valve 30 so that the coolant circulating through the stack cooling line 5 does not flow into the ion filter 70. While the second port of the first valve 100 is controlled to be fully opened from a fully closed state, the coolant circulating through the stack cooling line 5 can pass through the ion filter 70. Therefore, while the second port of the first valve 100 is maintained in a fully open state, it is not necessary to remove the ions contained in the coolant circulating through the stack cooling line 5 (S700).

[0097] When the high output mode of the fuel cell stack 10 is terminated, the controller 500 may control the first valve 100 so that the first port of the first valve 100 connected to the stack cooling line 5 is fully opened. While controlling the first port of the first valve 100 to be fully opened, the controller 500 may monitor the ion conductivity of the coolant circulating through the stack cooling line 5. When the ion conductivity of the coolant circulating through the stack cooling line 5 becomes equal to or greater than the threshold value before the first port of the first valve 100 is fully opened, the controller 500 may control the flow control valve 30 so as to remove ions contained in the coolant circulating through the stack cooling line 5 (S800).

[0098] Figure 7 is a diagram showing a cooling structure of an air cooler according to another embodiment of the present invention. Figure 1 A repeated description of the same structure shown in .

[0099] Reference Figure 7 , a separate valve may not be provided on the collecting line 9. The stack coolant circulating through the stack cooling line 5 and the electronic component coolant circulating through the electronic component cooling line 6 may be coolants composed of the same components.

[0100] When the first port of the first valve 100 is fully opened and the second valve 110 is fully opened, only the stack coolant may flow into the air cooler 200. The stack coolant that has cooled the air cooler 200 may flow into the stack cooling line 5 through the collecting line 9.

[0101] When the first port of the first valve 100 is partially opened and the second valve 110 is partially opened, the stack coolant and the electronic component coolant may flow into the air cooler 200. The stack coolant and the electronic component coolant that have cooled the air cooler 200 may be mixed, the mixture thereof may circulate through the electronic component cooling line 6, and a portion of the mixture may flow into the stack cooling line 5 through the collecting line 9. When the electronic component coolant flows into the stack cooling line 5 and thus the ion conductivity of the coolant circulating through the stack cooling line 5 becomes equal to or greater than a threshold value, the controller controlling the first valve 100 may control the flow control valve 30 so that the coolant flows into the ion filter 70.

[0102] When the first port of the first valve 100 is completely closed and the second valve 110 is completely closed, the electronic component coolant may flow into the air cooler 200. The electronic component coolant that has cooled the air cooler 200 may circulate through the electronic component cooling line 6, and a portion thereof may flow into the stack cooling line 5 through the collecting line 9. The situation in which the first port of the first valve 100 is completely closed and the second valve 110 is completely closed corresponds to the situation in which the fuel cell stack 10 is in a high output mode. Usually the fuel cell stack 10 is maintained in a high output mode for a short time. Therefore, when the first port of the first valve 100 is completely closed and the second valve 110 is completely closed, the controller may control the flow control valve 30 so that the coolant flows into the ion filter 70, thereby preventing the ionic conductivity of the coolant circulating through the stack cooling line 5 from increasing.

[0103] According to an embodiment of the present invention, even if the coolant discharged from the air cooler 200 is circulated to the collecting line 9 of the stack cooling line 5 and is always maintained in an open state, the ionic conductivity of the coolant circulating through the stack cooling line 5 can be prevented from increasing by controlling the flow control valve 30. Since no valve is provided on the collecting line 9, a situation in which the electronic component coolant flows into the stack cooling line 5 may occur relatively frequently. However, the controller may temporarily control the flow control valve 30 so that the coolant circulating through the stack cooling line 5 flows into the ion filter 70, thereby preventing the ionic conductivity of the coolant circulating through the stack cooling line 5 from increasing.

[0104] As should be clear from the above description, according to one aspect of the present invention, since the temperature of the coolant supplied to the air cooler by the three-way valve is controlled in a wide range, the temperature of the air supplied from the air cooler to the humidifier can be controlled in a wide range. Therefore, the temperature of the air supplied to the humidifier can be actively controlled, thereby improving the humidification performance of the humidifier.

[0105] According to an aspect of the present invention, by preventing the temperature of air flowing into a fuel cell stack from being excessively reduced or increased, stable performance of the fuel cell stack can be ensured, and the durability of the fuel cell stack can be improved.

[0106] According to one aspect of the invention, in normal mode, a relatively high temperature stack coolant can be used to adjust the temperature of the air cooler to prevent droplets from flowing into the fuel cell stack. In high output mode, a relatively low temperature electronic component coolant can be used to achieve maximum cooling of the air cooler.

[0107] According to an aspect of the present invention, when electronic component coolant flows into the stack cooling line, the controller may control the flow control valve to circulate the coolant to the ion filter, thereby preventing the ion conductivity of the coolant circulating through the stack cooling line from increasing.

[0108] According to an aspect of the present invention, when the cooling performance of the air cooler needs to be ensured due to the high output mode of the fuel cell stack, only the electronic component coolant that has cooled the air compressor flows into the air cooler through the first valve, thereby maximally cooling the air cooler.

[0109] According to an aspect of the present invention, coolant exhausted from the air cooler circulates along the electronic component cooling line and can be prevented to the greatest extent possible from flowing into the stack cooling line through a collecting line branched from the electronic component cooling line and a second valve arranged on the collecting line.

[0110] The present invention has been described above with reference to several embodiments. The embodiments described in the specification and shown in the drawings are exemplary only and are not intended to represent all aspects of the present invention. Therefore, the present invention is not limited to the embodiments presented herein, and it should be understood by those skilled in the art that various modifications or changes may be made without departing from the technical ideas or essential features of the present invention as set forth in the appended claims.

Claims

1. A structure for cooling an air cooler, the structure comprising: a stack cooling line configured to circulate a stack coolant for cooling the fuel cell stack therein; an electronic component cooling line configured to circulate an electronic component coolant for cooling the electronic components therein; an air cooler, disposed on the electronic component cooling line to cool air supplied to the cathode of the fuel cell stack; a first valve connected to a front side of the air cooler to supply at least one of the stack coolant and the electronic component coolant to the air cooler; as well as A bypass line connects the electronic component cooling line upstream of the first valve to the electronic component cooling line downstream of the air cooler so that the electronic component coolant bypasses the air cooler.

2. The structure according to claim 1, wherein: The first valve is disposed on a branch line connecting the air cooler to a front side of the fuel cell stack.

3. The structure according to claim 1, further comprising: A second valve is disposed on the bypass line; as well as A third valve is disposed on a collecting line connecting the air cooler to a stack cooling line downstream of the fuel cell stack.

4. The structure according to claim 3, wherein: When the output of the fuel cell stack is less than a predetermined output, the first port of the first valve connected to the stack cooling line is fully opened, the second port of the first valve connected to the electronic component cooling line is fully closed, and the second valve and the third valve are opened.

5. The structure according to claim 4, wherein: When the output of the fuel cell stack becomes equal to or greater than the predetermined output, the first port of the first valve connected to the stack cooling line gradually closes, the second port of the first valve connected to the electronic component cooling line gradually opens, and the second valve and the third valve gradually close.

6. The structure according to claim 5, wherein: While the first port of the first valve is completely closed or the second port of the first valve is completely opened, the stack coolant and the electronic component coolant flow into the air cooler through the first valve.

7. The structure according to claim 3, wherein: When the output of the fuel cell stack is equal to or greater than a predetermined output, the first port of the first valve connected to the stack cooling line is completely closed, the second port of the first valve connected to the electronic component cooling line is completely opened, and the second valve and the third valve are completely closed when the first port of the first valve is completely closed.

8. The structure according to claim 7, wherein: When the first port of the first valve is completely closed, only the electronic component coolant flows into the air cooler; and The electronic component coolant that has cooled the air cooler circulates along the electronic component cooling line, and flows into the electronic component radiator arranged on the electronic component cooling line.

9. The structure according to claim 3, wherein: The opening angles of the second valve and the third valve correspond to the opening angle of the first port of the first valve.

10. The structure according to claim 1, further comprising a controller configured to control the first valve and a flow control valve configured on the stack cooling line, in, The controller controls the first valve and the flow control valve based on an output of the fuel cell stack, and When the electronic component coolant and the stack coolant flow into the air cooler simultaneously through the first valve, the controller controls the flow control valve so that the coolant circulates to the ion filter arranged on the stack cooling line.

11. The structure according to claim 10, wherein: When the opening degree of the first port of the first valve connected to the stack cooling line changes based on the output of the fuel cell stack, the controller controls the flow control valve based on the ionic conductivity of the coolant circulating through the stack cooling line so that the coolant circulates to the ion filter.

12. The structure according to claim 11, wherein: The controller controls the flow control valve so that coolant circulates to the ion filter for a predetermined period of time when the first port of the first valve is closed from a fully open state and when the second port of the first valve connected to the electronic component cooling line is closed from a fully open state.

13. The structure according to claim 12, wherein: The predetermined period of time is a period of time shorter than a period of time taken for the first port of the first valve to be fully closed from a fully open state or a period of time taken for the second port of the first valve to be fully closed from a fully open state.

14. The structure according to claim 1, further comprising a second valve disposed on the bypass line, in, When the first valve is controlled to allow the electronic component coolant to flow into the air cooler, the second valve is opened.

15. A structure for cooling an air cooler, the structure comprising: a stack cooling line configured to circulate a stack coolant for cooling the fuel cell stack therein; an electronic component cooling line configured to circulate an electronic component coolant for cooling the electronic components therein; an air cooler, disposed on the electronic component cooling line to cool air supplied to the cathode of the fuel cell stack; as well as a first valve connected to a front side of the air cooler to supply at least one of the stack coolant and the electronic component coolant to the air cooler, wherein the first valve is controlled based on the output of the fuel cell stack, and When the first valve is controlled, a flow control valve arranged on the stack cooling line is controlled based on the ion conductivity of the stack coolant, so that the stack coolant flows into the ion filter arranged on the stack cooling line.

16. The structure of claim 15, further comprising: a bypass line connecting the electronic component cooling line upstream of the first valve to the electronic component cooling line downstream of the air cooler so that the electronic component coolant bypasses the air cooler, Wherein, a second valve is arranged on the bypass line.

17. The structure according to claim 16, wherein: The opening angle of the second valve corresponds to the opening angle of the first port of the first valve connected to the stack cooling line.

18. The structure according to claim 17, wherein: When the first port of the first valve is closed from a fully open state and when the second port of the first valve connected to the electronic component cooling line is closed from a fully open state, a flow control valve arranged on the stack cooling line is controlled so that coolant flows into the ion filter within a predetermined period of time.

19. The structure of claim 15, wherein: When the output of the fuel cell stack is less than a predetermined output, the first port of the first valve connected to the stack cooling line is fully opened, and the second port of the first valve connected to the electronic component cooling line is fully closed.

20. The structure of claim 15, wherein: When the output of the fuel cell stack is equal to or greater than a predetermined output, the first valve is controlled so that a first port of the first valve connected to the stack cooling line is fully closed and a second port of the first valve connected to the electronic component cooling line is fully opened.

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