Cooling structure for an air cooler

Abstract

A cooling structure for an air cooler may include: a stack cooling line through which stack coolant circulates to cool a fuel cell stack; an electronic component cooling line through which electronic component coolant circulates to cool an electronic component; an air cooler disposed on the electronic component cooling line for cooling air supplied to a cathode of the fuel cell stack; and a first valve connected to the front of the air cooler for supplying at least one of the stack coolant and the electronic component coolant to the air cooler. The cooling structure for an 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 to allow the electronic component coolant to bypass the air cooler.

Description

BACKGROUND(a) Technical field

[0001] The present disclosure relates to a cooling structure for an air cooler capable of preventing an increase in ionic conductivity of a stack coolant while using at least one of a stack coolant or electronic component coolant to cool an air cooler for cooling air supplied to a fuel cell stack. (b) State of the art

[0002] A fuel cell system is a power generation system that produces electrical energy through the electrochemical reaction between hydrogen and oxygen using a fuel cell. The fuel cell system is used in environmentally friendly vehicles, such as electric or hybrid vehicles, to provide the electrical energy required to operate an electric motor.

[0003] The fuel cell system includes a fuel cell stack, which is a power-generating assembly of unit fuel cells. Each includes an air electrode and a fuel electrode, an air supply device configured to supply air to the air electrode of the fuel cell, and a hydrogen supply device configured to supply hydrogen to the fuel electrode of the fuel cell. The air supply device may include an air compressor configured to supply compressed air to the fuel cell stack.

[0004] In a polymer fuel cell, an adequate amount of moisture is required for the ion exchange membrane of a membrane electrode assembly (MEA) to function smoothly, i.e., evenly or efficiently. For this purpose, the air supply device of the fuel cell system includes a humidifier to humidify the air supplied to the fuel cell by the air compressor. The humidifier humidifies, for example, the dry air supplied by the compressor using moisture contained in the high-temperature, high-humidity air (wet 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, possibly superheated by the compressor, is directed to an air cooler to be cooled before being fed to the humidifier. The air cooler requires a refrigerant to cool the superheated air. Typically, additional outside air, electronic component coolant in the fuel cell system, or stack coolant for cooling the fuel cell stack are used to cool the air cooler.

[0006] However, the temperature of the electronic component coolant is close to the outside air temperature. If the air cooler is cooled only with the electronic component coolant in a situation where the outside air temperature is low, water droplets will be introduced into the fuel cell stack, resulting in a deterioration in the durability of the fuel cell stack. Furthermore, using the electronic component coolant to cool the air cooler will result in insufficient cooling of the electronic components.

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

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

[0009] The above information disclosed in this Background section is intended merely to enhance the understanding of the background of the disclosure. Therefore, the Background section may contain information that is not prior art and that would be readily known to a person skilled in the art. SUMMARY OF REVELATION

[0010] The present disclosure was made in an effort to solve the above-described problems associated with the prior art. It is an object of the present disclosure to provide a cooling structure for an air cooler capable of preventing an increase in the ionic conductivity of the stack coolant in a process in which at least one of a stack coolant or an electronic component coolant is used to cool an air cooler for cooling air supplied to a fuel cell stack.

[0011] In one aspect, the present disclosure provides a structure for cooling an air cooler. The structure for cooling an air cooler includes a stack cooling line configured to allow stack coolant to circulate therethrough for cooling a fuel cell stack, an electronic component cooling line configured to allow electronic component coolant to circulate therethrough, an air cooler disposed on the electronic component cooling line to cool air supplied to a 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 or the electronic component coolant to the air cooler.The air cooler cooling structure includes 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 to allow the electronic component coolant to bypass the air cooler.

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

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

[0014] In another embodiment, when the power of the fuel cell stack is less than a predetermined power, a first opening of the first valve connected to the stack cooling line may be fully opened, a second opening 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 another embodiment, when the power of the fuel cell stack becomes equal to or greater than the predetermined power, the first opening of the first valve connected to the stack cooling line may be successively closed, the second opening of the first valve connected to the electronic component cooling line may be successively opened, and the second valve and the third valve may be successively closed.

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

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

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

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

[0020] In another embodiment, the air cooler cooling structure may further include a controller configured to control the first valve and a flow control valve disposed on the stack cooling line, and the controller may control the first valve and the flow control valve based on a performance of the fuel cell stack. When the electronic component coolant and the stack coolant flow into the air cooler through the first valve at the same time, the controller may control the flow control valve so that the coolant circulates to an ion filter disposed in the stack cooling line.

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

[0022] In another embodiment, when the first opening of the first valve is closed from a fully open state and when the second opening 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 for a predetermined period of time.

[0023] In yet another embodiment, the predetermined time period may be a time period shorter than a time period required to completely close the first opening of the first valve from a fully open state or a time period required to completely close the second opening of the first valve from a fully open state.

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

[0025] In another aspect, the present disclosure provides a structure for cooling air. The air cooler cooling structure includes a stack cooling line configured to allow stack coolant to circulate therethrough for cooling a fuel cell stack, an electronic component cooling line configured to allow electronic component coolant to circulate therethrough for cooling an electronic component, an air cooler disposed on the electronic component cooling line for cooling air supplied to a cathode of the fuel cell stack, and a first valve connected to the air cooler for supplying at least one of the stack coolant and the electronic component coolant to the air cooler. The first valve is controlled depending on the performance of the fuel cell stack.When the first valve is controlled, a flow control valve arranged 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 arranged on the stack cooling line.

[0026] In one embodiment, the structure for cooling an 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 to allow the electronic component coolant to bypass the air cooler, and a second valve may be arranged on the bypass line.

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

[0028] In another embodiment, when the first opening of the first valve is closed from a fully open state and when a second opening 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 may be controlled so that coolant flows into the ion filter for a predetermined period of time.

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

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

[0031] Further aspects and embodiments of the disclosure are discussed herein.

[0032] It should be understood that the terms “vehicle” or “vehicle” or other similar terms as used herein encompass motor vehicles in general. Thus, these terms may include passenger cars including sport utility vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like. 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 derived from resources other than petroleum). A hybrid vehicle is a vehicle that has two or more power sources, e.g., a vehicle powered by both gasoline and electricity.

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

[0034] The above and other features of the present disclosure will be described in detail with reference to specific embodiments illustrated in the accompanying drawings, which are given below for illustrative purposes only and thus do not limit the present disclosure, and wherein: Fig. 1 is a diagram showing a cooling structure for an air cooler according to an embodiment of the present disclosure; Fig. 2 is a block diagram for explaining control strategies of valves according to an embodiment of the present disclosure; Fig. 3-5 are diagrams for explaining a control strategy of a first valve according to the performance of a fuel cell stack according to an embodiment of the present disclosure; Fig. 6 is a flowchart illustrating a method for controlling the cooling structure for an air cooler according to an embodiment of the present disclosure; and Fig. 7 is a diagram showing a cooling structure for an air cooler according to another embodiment of the present disclosure.

[0035] It should be understood that the accompanying drawings are not necessarily drawn to scale and present a somewhat simplified representation of various features illustrating the basic principles of the disclosure. The specific design features of the present disclosure as disclosed herein, including, for example, specific dimensions, orientations, positions, and shapes, will be determined in part by the particular intended application and environment of use.

[0036] In the figures, the same reference numerals refer to the same or equivalent parts of the present disclosure in the different figures of the drawing. DETAILED DESCRIPTION

[0037] Advantages and features of the present disclosure and methods of carrying them out should become more apparent from the embodiments described in detail below with reference to the accompanying drawings. The present disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure is thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. The present disclosure is defined only by the scope of the claims. Throughout this specification, the same reference numerals represent the same components.

[0038] The terms “part”, “unit” and “module” used in the description refer to units for processing at least one function or operation and can be implemented as hardware components, software components or combinations of hardware components and software components.

[0039] Furthermore, in the following description, the terms "first" and "second" are used only to avoid confusion among the designated components and do not indicate the order or importance of the components or the relationships between the components. When a component, device, element, or the like of the present disclosure is described as having a purpose or performing an operation, function, or the like, the component, device, or element should be considered herein as "configured to" fulfill that purpose or perform that operation or function.

[0040] The detailed description is provided to illustrate the present disclosure. The following description is intended to illustrate and explain the embodiments of the present disclosure, and the present disclosure may be used in various other combinations, modifications, and environments. In other words, the present disclosure may be changed or modified within the scope of the inventive concept disclosed herein, the scope of equivalents to the disclosure, and / or the scope of technology or knowledge in the art. The described embodiments represent one example of implementing the technical spirit of the present disclosure, and various changes may be made thereto as required for particular applications and uses of the present disclosure.Accordingly, the following detailed description is not intended to limit the present disclosure to the embodiments disclosed herein. The appended claims should also be interpreted to include such other embodiments.

[0041] Fig. 1 is a diagram showing a cooling structure for an air cooler according to an embodiment of the present disclosure. Fig. 2 is a block diagram for explaining control strategies of valves according to an embodiment of the present disclosure.

[0042] With reference to the Fig. 1 and Fig. 2, the cooling structure for an air cooler may be a structure capable of cooling an air cooler 200 for cooling air supplied to a fuel cell stack 10 using either a coolant circulating through a stack cooling line 5 or a coolant circulating through an electronic component cooling line 6. The stack cooling line 5 may be a line through which stack coolant flows to cool the fuel cell stack 10. The electronic component cooling line 6 may be a line through which electronic component coolant flows to cool the electronic components 230, 240, 250, 260, and 270.

[0043] The fuel cell stack 10, a cooler 20, a flow control valve 30, a cathode oxygen depletion (COD) heater 40, a heater core 50, a coolant pump 60, and an ion filter 70 may be arranged in the stack cooling line 5.

[0044] The fuel cell stack 10 can generate electricity through a chemical reaction between air and supplied hydrogen. The fuel cell stack 10 can be a polymer electrolyte membrane fuel cell (PEMFC), which uses a polymer membrane through which hydrogen ions can pass as an electrolyte. In other words, the fuel cell stack 10 can comprise a polymer electrolyte membrane or a proton exchange membrane (PEM). The power generation efficiency of the fuel cell stack 10 can vary depending on the moisture supplied to the polymer electrolyte membrane. The fuel cell stack 10 can comprise a fuel electrode (anode) and an air electrode (cathode). Reformed hydrogen can be supplied to the fuel electrode of the fuel cell stack 10, and air (oxygen) can be supplied to the air electrode of the fuel cell stack 10.Coolant may be introduced into the fuel cell stack 10 to dissipate the heat generated as a byproduct of the chemical reaction between hydrogen and oxygen in the fuel cell stack 10. While the fuel cell stack 10 generates electrical energy through the electrochemical reaction between hydrogen and air, high-temperature, high-humidity air may be discharged from the air electrode of the fuel cell stack 10.

[0045] The cooler 20 can cool the coolant that has increased in temperature after the chemical reaction in the fuel cell stack 10. The cooled coolant can flow to the flow control valve 30. A reservoir 25 can regulate the coolant pressure of the fuel cell thermal management system. The reservoir 25 can suppress the occurrence of cavitation in the coolant pump 60 and regulate the coolant pressure to prevent the pressure of the fuel cell stack 10 from exceeding a predetermined internal pressure. Cavitation is a phenomenon in which impulsive noise or erosion occurs when bubbles generated in a high-speed and low-pressure part of the coolant pump 60 migrate to a high-pressure part and disappear. In addition, the reservoir 25 can store the coolant to regulate the coolant pressure.The reservoir 25 may be arranged downstream of the fuel cell stack 10 and between the fuel cell stack 10 and the front 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 arranged parallel to the radiator 20.

[0046] The flow control valve 30 can control the path and flow rate of the coolant flowing through the stack cooling line 5. The flow control valve 30 can be a 5-way valve. However, unlike the example described above, the valve constituting the fuel cell thermal management system can also include at least one of a 4-way valve or a 3-way valve. The coolant can flow from the fuel cell stack 10, the cooler 20, the COD heater 40, and the ion filter 70 to the flow control valve 30. The coolant can flow from the flow control valve 30 to the coolant pump 60. The flow control valve 30 can be controlled according to an opening strategy that varies depending on the performance of the fuel cell stack 10 or the operating mode of the thermal management system.

[0047] The COD heater 40 may consume the energy generated by the fuel cell stack 10 to increase the coolant temperature when an increase in the coolant temperature is required, or to decrease the voltage of the fuel cell stack 10. Specifically, when the fuel cell system is turned on or off, and when regenerative braking is continuously performed in the state where the state of charge (SOC) of a high-voltage battery is sufficient, the COD heater 40 may operate to consume the energy generated by the fuel cell stack 10.

[0048] The heater core 50 may be a component that performs interior heating of the vehicle through heat exchange between the coolant whose temperature has been increased by the COD heater 40 and the outside air. During interior heating, the coolant whose temperature has been increased by the COD heater 40 may flow into the heater core 50 to heat the heater core 50, and high-temperature air may flow into the interior of the vehicle through the heat exchange between the compressed outside air and the heated coolant in the heater core 50.

[0049] The coolant pump 60 can supply the coolant supplied from the flow control valve 30 to the fuel cell stack 10, the COD heater 40, or the ion filter 70.

[0050] The ion filter 70 can remove ions contained in the coolant. The ion filter 70 can remove ions contained in the coolant supplied by the coolant pump 60, and the coolant with the ions removed therefrom can be supplied to the flow control valve 30.

[0051] An air cooler 200, an electronic component cooler 210, an electronic component coolant pump 220, electronic components 230, 240, 250, 260 and 270 and an air compressor 280 may be arranged in the electronic component cooling line 6.

[0052] The air cooler 200 can perform heat exchange between high-temperature air and refrigerant to cool the high-temperature air. In other words, the air cooler 200 can cool the air supplied to the cathode of the fuel cell stack 10. The refrigerant can be a coolant. In one example, the coolant used as the refrigerant can include at least one of a stack coolant for cooling the fuel cell stack 10 or an electronic component coolant for cooling the electronic components 230, 240, 250, 260, and 270. The air cooled by the coolant can be supplied to a humidifier 400. The temperature of the air supplied from the air cooler 200 to the humidifier 400 can vary depending on the temperature of the coolant supplied to the air cooler 200.

[0053] The electronic component cooler 210 can cool the coolant whose temperature has increased during the cooling of the electronic components 230, 240, 250, 260, and 270. The coolant cooled by the electronic component cooler 210 can be supplied to the electronic component coolant pump 220. The electronic component coolant pump 220 can supply the cooled coolant to the electronic components 230, 240, 250, 260, and 270.

[0054] 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.

[0055] 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 a vehicle-mounted high-voltage battery and a low-voltage DC-DC converter (LDC) that converts the high voltage supplied by the high-voltage battery to low voltage are integrated. The coolant supplied by 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.

[0056] The external power supply unit 240 may include a component (Vehicle to Load (V2L)) that routes the power from the vehicle-mounted high-voltage battery to the outside. The coolant that the external power supply unit 240 has cooled may flow into the air compressor 280.

[0057] The air compressor 280 can compress outside air and supply the compressed outside air to the air cooler 200. The outside air can flow through the air filter 300 and then flow into the air compressor 280, removing foreign matter. When the air compressor 280 compresses the air, the pressure and temperature of the air can be increased, and the high-temperature and high-pressure air can be supplied to the air cooler 200.

[0058] The power distribution unit (PDU) 250 may be a device that controls the power supply. The coolant supplied by 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.

[0059] Inverter 260 may be a component that converts the power applied or provided to motor 270, which provides the motive power required to propel the vehicle. The coolant that cooled inverter 260 may flow into motor 270.

[0060] The motor 270 can provide the driving force required to propel the vehicle. The coolant that cooled the inverter 260 can cool the motor 270 or an oil cooler that provides oil to cool the motor 270. The coolant that cooled the motor 270 or the oil cooler can flow into the cooler of the electronic component 210.

[0061] Humidifier 400 may humidify the air supplied by air cooler 200. Humidifier 400 may then supply the humidified air to the cathode (air electrode) of fuel cell stack 10. Humidifier 400 may, for example, be a membrane humidifier, but the disclosure is not limited to any particular type of humidifier 400. The dry air cooled by air cooler 200 may flow into fuel cell stack 10 via humidifier 400.

[0062] A first valve 100 for controlling the coolant flowing into the air cooler 200 may be connected to the front (e.g., upstream) of the fuel cell stack 10. In detail, the first valve 100 may be arranged on a branch line 7 connecting the air cooler 200 to the front of the fuel cell stack 10. Furthermore, the first valve 100 may be connected to the electronic component cooling line 6. The coolant that has cooled the 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 arranged at the front (e.g., upstream) of the air cooler 200. The first valve 100 may, for example, be a 3-way valve. The first valve 100 can supply at least one of the stack coolant from the stack cooling line 5 or electronic component coolant from the electronic component cooling line 6 to the air cooler 200.

[0063] The first valve 100 may include a first opening connected to the stack cooling line 5, a second opening connected to the electronic component cooling line 6, and a third opening that discharges the coolant to the air cooler 200. In detail, the stack coolant supplied from the stack cooling line 5 may flow into the first opening, and the coolant that has cooled the air compressor 280 may flow into the second opening. The opening degrees of the first opening and the second opening may be controlled, for example, by controlling the opening degree of the first valve 100. The third opening may always be kept in an open state. Therefore, the first valve 100 can supply the air cooler 200 with at least one of the stack coolant flowing into the first opening and the electronic component coolant flowing into the second opening.

[0064] The air cooler cooling structure may include a bypass line 8 for redirecting the coolant that has cooled the air compressor 280 to the electronic component cooler 210. The bypass line 8 may be branched from a line between the air compressor 280 and the first valve 100 and may be connected to the rear (e.g., downstream) side 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 opening of the first valve 100 is fully closed, the coolant that has cooled the air compressor 280 cannot circulate to the air cooler 200, but can circulate along the bypass line 8 and flow into the electronic component cooler 210. A second valve 110 may be arranged in the bypass line 8.The second valve 110 may not be an on / off valve, but may be a two-way valve that successively opens or closes the bypass line 8. Even if the electronic component coolant that has 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. Accordingly, the electronic components 230, 240, 250, 260, and 270 can be continuously cooled.

[0065] The coolant discharged from the air cooler 200 may circulate along the electronic component cooling line 6. A manifold 9 branching from the electronic component cooling line 6 may be connected downstream of the air cooler 200. The manifold 9 may branch from the electronic component cooling line 6 and be connected to the stack cooling line 5. In detail, the manifold 9 may branch from the electronic component cooling line 6 downstream of the air cooler 200 and be connected to the stack cooling line 5 downstream of the fuel cell stack 10. The coolant circulating through the manifold 9 may be the stack coolant or a mixture of the stack coolant and the electronic component coolant. Thus, the stack coolant and the electronic component coolant may be coolants formed from the same components.The coolant circulating through the manifold 9 can flow into the stack cooling line 5 downstream of the fuel cell stack 10 and then flow into the cooler 20. A third valve 120 can be arranged in the manifold 9. The third valve 120 may not be an on / off valve, but may be a two-way valve that successively opens or closes the manifold 9. When only the electronic component coolant flows into the air cooler 200, the third valve 120 is closed, thereby largely preventing the electronic component coolant from flowing into the stack cooling line 5.

[0066] A 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 performance of the fuel cell stack 10 and the ionic conductivity of the coolant circulating through the stack cooling line 5. The opening angles or degrees of the second valve 110 and the third valve 120 may correspond to the opening angle or degree of the first opening of the first valve 100. In other words, when the first opening of the first valve 100 is fully open, the second valve 110 and the third valve 120 may be fully open, and when the first opening of the first valve 100 is fully closed, the second valve 110 and the third valve 120 may be fully closed.When the first opening of the first valve 100 is successively closed, the second valve 110 and the third valve 120 can be closed at the same angle as the first opening of the first valve 100, and when the first opening of the first valve 100 is successively opened, the second valve 110 and the third valve 120 can be opened at the same angle as the first opening of the first valve 100.

[0067] The controller 500 may control the first valve 100 depending on whether the power of the fuel cell stack 10 is equal to or greater than a predetermined power. The fuel cell thermal management system may control the coolant flow path differently depending on a normal power mode or a high power mode of the fuel cell stack 10. The predetermined power may be a reference value used to determine whether the fuel cell stack 10 is in the high power mode. When the power of the fuel cell stack 10 is equal to or greater than the predetermined power, 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 power of the fuel cell stack 10 is lower than the predetermined power, the air supplied to the fuel cell stack 10 may be overcooled when the electronic component coolant, which has a relatively low temperature, flows into the air cooler 200. Accordingly, droplets may be introduced into the fuel cell stack 10, affecting the durability of the fuel cell stack 10. Therefore, 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.

[0068] 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. 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 manifold 9. The electronic component coolant may have a higher ionic conductivity than the stack coolant. Therefore, when the electronic component coolant flows into the stack cooling line 5, a problem may occur in which the ionic conductivity of the coolant circulating through the stack cooling line 5 increases. 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.The electronic component coolant may flow into the stack cooling line 5 when the fuel cell stack 10 is in high power mode. When the fuel cell stack 10 is in high power mode, the controller 500 may control the flow control valve 30 to temporarily allow the coolant to flow into the ion filter 70.

[0069] According to one aspect of the present disclosure, since the temperature of the coolant supplied to the air cooler 200 through the first valve 100 is controlled over a wide range, the temperature of the air supplied from the air cooler 200 to the humidifier 400 can be controlled over a wide range. Accordingly, the temperature of the air supplied to the humidifier 400 can be actively controlled, thereby improving the humidification performance of the humidifier 400.

[0070] According to one aspect of the present disclosure, stable performance of the fuel cell stack 10 can be ensured and its durability can be improved by preventing the temperature of the air flowing into the fuel cell stack 10 from excessively decreasing or increasing.

[0071] According to one aspect of the present disclosure, in normal mode, the stack coolant having a relatively high temperature may be used to regulate the temperature of the air cooler 200 to prevent droplets from flowing into the fuel cell stack 10. In high power mode, the electronic component coolant having a relatively low temperature may be used to achieve maximum cooling of the air cooler 200.

[0072] The Fig. 3-5 are diagrams for explaining a control strategy of the first valve depending on the performance of the fuel cell stack according to an embodiment of the present disclosure. Fig. 3 is a diagram showing a situation where only the stack coolant is introduced into the air cooler through the first valve when the power of the fuel cell stack is less than the predetermined power. Fig. 4 is a diagram showing a situation in which both the stack coolant and the electronic component coolant are introduced into the air cooler through the first valve when the power of the fuel cell stack is equal to or greater than the predetermined power. Fig. 5 is a diagram showing a situation in which only the electronic component coolant is introduced into the air cooler through the first valve when the power of the fuel cell stack is equal to or greater than the predetermined power.

[0073] With reference to the Fig. 2 and Fig. 3, the controller 500 may fully open the first opening of the first valve 100 connected to the stack cooling line 5 when the power of the fuel cell stack 10 is less than the predetermined power. When the vehicle is in a normal driving situation, the power of the fuel cell stack 10 is less than the predetermined power. In this case, the first opening of the first valve 100 may be maintained in an open state. Furthermore, the second opening of the first valve 100 connected to the electronic component cooling line 6 may be fully closed, and the second valve 110 and the third valve 120 may be in a fully open state to correspond to the first opening of the first valve 100.Therefore, only the stack coolant can be supplied to the air cooler 200, and the stack coolant that has cooled the air cooler 200 can circulate through the manifold 9 to the stack cooling line 5. The electronic component coolant that has cooled the electronic components 230, 240, 250, 260, and 270 can circulate along the bypass line 8 and flow into the electronic component cooler 210. Since the electronic component coolant does not flow into the stack cooling line 5, the controller 500 does not need to control the flow control valve 30 to allow the coolant to flow into the ion filter 70.

[0074] With reference to the Fig. 2 and Fig. 4, when the power of the fuel cell stack 10 is equal to or greater than the predetermined power, the controller 500 may control the first valve 100 such 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 successively closed and the second port of the first valve 100 may be successively opened. The second valve 110 and the third valve 120 may be successively closed in the same manner as the opening strategy of the first port of the first valve 100.

[0075] When the first opening of the first valve 100, the second valve 110, and the third valve 120 are successively closed, both the stack coolant and the electronic component coolant can flow into the air cooler 200. The stack coolant can flow through the branch line 7 into the first opening of the first valve 100 and through the opened first opening of the first valve 100 into the air cooler 200. The electronic component coolant that has cooled the air compressor 280 can flow into the second opening of the first valve 100 and flow through the second opening of the first valve 100 into the air cooler 200. When the second valve 110 is successively closed, the coolant that has cooled the air cooler 200 can be discharged into the manifold 9 and the electronic component cooling line 6. When the third valve 120 is successively closed, the electronic component coolant can 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 that the electronic component coolant flows into the stack cooling line 5. In this case, the controller 500 can 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.

[0076] When the electronic component coolant flows through the manifold 9 into the stack cooling line 5, 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 detected by an ionic conductivity sensor, so that the coolant flows into the ion filter 70. When the opening degree of the first valve 100 is changed, 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 degree of the first valve 100 is changed may correspond to a case where the first opening of the first valve 100 is closed from a fully open state and a case where the second opening of the first valve 100 is closed from a fully open state. In other words, when the first opening of the first valve 100 is maintained in a fully open state and when the first opening of the first valve 100 is maintained in a fully closed state, the controller 500 may determine that there is no need to remove ions contained in the coolant circulating through the stack cooling line 5. Furthermore, when the opening degree of the first valve 100 is changed when the ion conductivity is below a threshold value, the controller 500 may not control the flow control valve 30 so that the coolant can circulate to the ion filter 70.When the opening degree of the first valve 100 is changed 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 a period of time required to fully close the first opening of the first valve 100 from a fully open state or a period of time required to fully close the second opening of the first valve 100 from a fully open state. However, the predetermined period of time may be a period of time that can be changed by a designer.

[0077] With reference to the Fig. 2 and Fig. 5, when the power of the fuel cell stack 10 is equal to or greater than the predetermined power, the opening degree of the first valve 100 can be successively changed so that the first opening of the first valve 100 is fully closed and the second opening of the first valve 100 is fully opened. In this case, the second valve 110 and the third valve 120 can be fully closed in the same manner as the opening strategy of the first opening of the first valve 100. Therefore, only the low-temperature electronic component coolant that has cooled the air compressor 280 can flow into the air cooler 200, and the stack coolant cannot flow into the air cooler 200. Since the third valve 120 is in a fully closed state, the electronic component coolant that has cooled the air compressor 280 can only circulate to the air cooler 200.Since the first valve 110 is in a fully closed state, the electronic component coolant that has cooled the air cooler 200 can circulate along the electronic component cooling line 6.

[0078] While the first opening of the first valve 100 is maintained in a fully closed state, the controller 500 may determine that there is no need to allow the coolant to flow into the ion filter 70. Since the second valve 110 is in a fully closed state, the electronic component coolant cannot flow through the manifold 9 into the stack cooling line 5. Since there is no possibility of the ion conductivity of the coolant circulating through the stack cooling line 5 being increased by the inflow of the electronic component coolant, the controller 500 cannot control the flow control valve 30.

[0079] In contrast to the example described above, the flow control valve 30 can be controlled according to the control strategy of the fuel cell thermal management system. One aspect of the present disclosure illustrates that the first valve 100 and the flow control valve 30 are controlled depending on the performance of the fuel cell stack 10 and the ionic conductivity of the coolant circulating through the stack cooling line 5.

[0080] According to one aspect of the present disclosure, when the electronic component coolant flows into the stack cooling line 5, the controller 500 may control the flow control valve 30 to allow the coolant to circulate to the ion filter 70, thereby preventing an increase in the ion conductivity of the coolant circulating through the stack cooling line 5.

[0081] According to one aspect of the present disclosure, under the condition that the cooling performance of the air cooler 200 needs to be ensured due to the high power 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 110, thereby cooling the air cooler 200 to the maximum.

[0082] According to one aspect of the present disclosure, the coolant discharged from the air cooler 200 circulates along the electronic component cooling line 6, and the inflow of the electronic component coolant into the stack cooling line 5 through the manifold 9 branching from the electronic component cooling line 6 and the second valve 120 arranged on the manifold 9 can be largely prevented.

[0083] Fig. 6 is a flowchart showing a method for controlling the air cooler cooling structure according to an embodiment of the present disclosure.

[0084] With reference to the Fig. 1, Fig. 2 and Fig. 6, the controller 500 may monitor whether the fuel cell stack 10 is operating in high power mode. When the fuel cell stack 10 is operating in high power 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, it may be difficult for the air cooler 200 to reduce the temperature of the air supplied to the fuel cell stack 10 to a desired temperature due to a relatively low cooling efficiency (S100).

[0085] When the fuel cell stack 10 is in the normal mode and not in the high power 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 power mode. Therefore, the air supplied to the fuel cell stack 10 can be cooled to a desired temperature even when the air cooler 200 is cooled with the stack coolant. The controller 500 may maintain the first opening of the first valve 100 connected to the stack cooling line 5 in a fully open state. Since the first opening 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).

[0086] When the fuel cell stack 10 is in the high power mode, the controller 500 may control the first valve 100 to fully open the second port of the first valve 100 connected to the electronic component cooling line 6, so that the electronic component coolant having a relatively low temperature flows into the air cooler 200. As the second port of the first valve 100 is successively opened, the second valve 110 and the third valve 120 may be successively closed (S300).

[0087] When the opening degree of the first valve 100 is changed, the controller 500 can measure the ionic conductivity of the coolant circulating through the stack cooling line 5. The ionic conductivity can be monitored at any time by the ionic conductivity sensor arranged in the stack cooling line 5 (S400).

[0088] When the ion conductivity of the coolant circulating through the stack cooling line 5 is below the threshold, the coolant circulating through the stack cooling line 5 cannot flow into the ion filter 70 even if the opening degree of the first valve 100 is changed. When the ion conductivity is below the threshold, the coolant is not allowed to flow into the ion filter 70 to ensure the durability of the ion filter 70 (S500).

[0089] When the ionic 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 for a predetermined period of time (S600).

[0090] The controller 500 can continuously monitor the performance of the fuel cell stack 10. When the high power mode of the fuel cell stack 10 is not terminated, the second opening of the first valve 100 can be maintained in a fully open state. Since the state in which the second opening of the first valve 100 is maintained in a fully open state is a state in which there is no change in the opening degree of the first valve 100, 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 opening 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 flow through the ion filter 70.Therefore, while the second opening of the first valve 100 is kept in a fully open state, there may be no need to remove the ions contained in the coolant circulating through the stack cooling line 5 (S700).

[0091] When the high power mode of the fuel cell stack 10 is ended, the controller 500 may control the first valve 100 to fully open the first opening of the first valve 100 connected to the stack cooling line 5. While the first opening of the first valve 100 is fully opened, the controller 500 may monitor the ionic conductivity of the coolant circulating through the stack cooling line 5. If the ionic conductivity of the coolant circulating through the stack cooling line 5 becomes equal to or greater than the threshold before the first opening of the first valve 100 is fully opened, the controller 500 may control the flow control valve 30 to remove the ions contained in the coolant circulating through the stack cooling line 5 (S800).

[0092] Fig. 7 is a diagram showing an air cooler cooling structure according to another embodiment of the present disclosure. For the sake of simplicity, a redundant description of the same configuration as in Fig. 1 omitted.

[0093] As in Fig. As shown in Figure 7, no separate valve may be arranged in the manifold 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 consisting of the same components.

[0094] When the first opening of the first valve 100 is fully open and the second valve 110 is fully open, only the stack coolant can flow into the air cooler 200. The stack coolant that has cooled the air cooler 200 can flow through the manifold 9 into the stack cooling line 5.

[0095] When the first opening of the first valve 100 is partially open and the second valve 110 is partially open, the stack coolant and the electronic component coolant can flow into the air cooler 200. The stack coolant and the electronic component coolant that have cooled the air cooler 200 can be mixed, a mixture of which can circulate through the electronic component cooling line 6, and a portion of the mixture can flow into the stack cooling line 5 through the manifold 9. When the electronic component coolant flows into the stack cooling line 5 and thus the ionic conductivity of the coolant circulating through the stack cooling line 5 becomes equal to or higher than a threshold value, the controller controlling the first valve 100 can control the flow control valve 30 so that the coolant flows into the ion filter 70.

[0096] When the first opening of the first valve 100 is fully closed and the second valve 110 is fully closed, the electronic component coolant can flow into the air cooler 200. The electronic component coolant that has cooled the air cooler 200 can circulate through the electronic component cooling line 6, and a portion of it can flow into the stack cooling line 5 through the manifold 9. The case where the first opening of the first valve 100 is fully closed and the second valve 110 is fully closed corresponds to a case where the fuel cell stack 10 is in the high power mode. It is common for the fuel cell stack 10 to be kept in the high power mode for a short period of time.Therefore, when the first opening of the first valve 100 is fully closed and the second valve 110 is fully closed, the controller can control the flow control valve 30 so that the coolant flows into the ion filter 70, thereby preventing an increase in the ion conductivity of the coolant circulating through the stack cooling line 5.

[0097] According to an embodiment of the present disclosure, an increase in the ionic conductivity of the coolant circulating through the stack cooling line 5 can be prevented by controlling the flow control valve 30 even if the manifold 9, which circulates the coolant discharged from the air cooler 200 to the stack cooling line 5, is always kept open. Since no valve is provided in the manifold 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 an increase in the ionic conductivity of the coolant circulating through the stack cooling line 5.

[0098] As should be apparent from the above description, according to one aspect of the present disclosure, since the temperature of the coolant supplied to an air cooler through a three-way valve is controlled over a wide range, the temperature of the air supplied from the air cooler to a humidifier can be controlled over a wide range. Accordingly, the temperature of the air supplied to the humidifier can be actively controlled, thereby improving the humidification performance of the humidifier.

[0099] According to one aspect of the present disclosure, stable performance of a fuel cell stack can be ensured and its lifetime can be improved by preventing the temperature of the air flowing into the fuel cell stack from excessively decreasing or increasing.

[0100] According to one aspect of the present disclosure, in a normal mode, the stack coolant having a relatively high temperature may be used to regulate the temperature of the air cooler to prevent droplets from flowing into the fuel cell stack. In a high power mode, an electronic component coolant having a relatively low temperature may be used to achieve maximum cooling of the air cooler.

[0101] According to one aspect of the present disclosure, when the electronic component coolant flows into a stack cooling line, a controller may control a flow control valve to allow the coolant to circulate to an ion filter, thereby preventing an increase in ionic conductivity of the coolant circulating through the stack cooling line.

[0102] According to one aspect of the present disclosure, under the condition that the cooling performance of the air cooler needs to be ensured due to the high power mode of the fuel cell stack, only the electronic component coolant that has cooled an air compressor flows into the air cooler through a first valve, thereby cooling the air cooler to the maximum.

[0103] According to one aspect of the present disclosure, the coolant discharged from the air cooler circulates along an electronic component cooling line, and the inflow of the electronic component coolant into the stack cooling line can be maximally prevented by a manifold branching from the electronic component cooling line and a second valve arranged on the manifold.

[0104] The present disclosure has been described above with reference to several embodiments. The embodiments described in the specification and illustrated in the accompanying drawings are merely exemplary and are not intended to represent all aspects of the disclosure. Therefore, the present disclosure is not limited to the embodiments illustrated herein, and those skilled in the art will understand that various modifications or changes may be made without departing from the technical spirit or essential features of the disclosure as disclosed in the appended claims.

Claims

[1] Structure for cooling an air cooler, the structure comprising: a stack cooling line configured to circulate stack coolant therethrough for cooling a fuel cell stack; an electronic component cooling conduit configured to circulate electronic component coolant therethrough for cooling an electronic component; an air cooler arranged on the electronic component cooling line for cooling the air supplied to a cathode of the fuel cell stack; a first valve connected to a front side of the air cooler for supplying at least one of the stack coolant or the electronic component coolant to the air cooler; and 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 to allow the electronic component coolant to bypass the air cooler. [2] The structure of 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 of claim 1 or 2, further comprising: a second valve arranged on the bypass line; and a third valve arranged on a manifold connecting the air cooler to the stack cooling line downstream of the fuel cell stack. [4] The structure according to claim 3, wherein, when a power of the fuel cell stack is less than a predetermined power, a first opening of the first valve connected to the stack cooling line is fully opened, a second opening 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 power of the fuel cell stack becomes equal to or greater than the predetermined power, the first port of the first valve connected to the stack cooling line is successively closed, the second port of the first valve connected to the electronic component cooling line is successively opened, and the second valve and the third valve are successively closed. [6] The structure according to claim 5, wherein, while the first opening of the first valve is fully closed or the second opening of the first valve is fully 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 a power of the fuel cell stack is equal to or greater than a predetermined power, 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, and the second valve and the third valve are fully closed in a fully closed state of the first port of the first valve. [8] Structure according to claim 7, wherein: when the first opening 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 an electronic component cooler arranged on the electronic component cooling line. [9] The structure according to claim 3, wherein opening angles of the second valve and the third valve correspond to an opening angle of a first opening of the first valve. [10] The structure of any preceding claim, further comprising a controller configured to control the first valve and a flow control valve disposed on the stack cooling line, wherein the controller controls the first valve and the flow control valve based on a performance of the fuel cell stack, and wherein, when the electronic component coolant and the stack coolant flow simultaneously through the first valve into the air cooler, the controller controls the flow control valve so that the coolant circulates to an ion filter disposed on the stack cooling line. [11] The structure according to claim 10, wherein, when an opening degree of a first opening of the first valve connected to the stack cooling line is changed based on the performance of the fuel cell stack, the controller controls the flow control valve based on an ion 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 when the first opening of the first valve is closed from a fully open state and when a second opening of the first valve connected to the electronic component cooling line is closed from a fully open state, the controller controls the flow control valve so that the coolant circulates to the ion filter for a predetermined period of time. [13] The structure according to claim 12, wherein the predetermined time period is a time period shorter than a time period required to completely close the first opening of the first valve from a fully open state or a time period required to completely close the second opening of the first valve from a fully open state. [14] The structure of claim 1, further comprising a second valve disposed on the bypass line, wherein when the first valve is controlled to allow the electronic component coolant to flow into the air cooler, the second valve is opened. [15] Structure for cooling an air cooler, the structure comprising: a stack cooling line configured to circulate stack coolant therethrough for cooling a fuel cell stack; an electronic component cooling conduit configured to circulate electronic component coolant therethrough for cooling an electronic component; an air cooler arranged on the electronic component cooling line for cooling air supplied to a cathode of the fuel cell stack; and a first valve connected to the air cooler for supplying at least one of the stack coolant or the electronic component coolant to the air cooler, wherein the first valve is controlled based on a performance of the fuel cell stack, and wherein, when the first valve is controlled, a flow control valve disposed on the stack cooling line is controlled based on an ion conductivity of the stack coolant so that the stack coolant flows into an ion filter disposed 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 can bypass the air cooler, wherein a second valve is arranged on the bypass line. [17] The structure of claim 16, wherein an opening angle of the second valve corresponds to an opening angle of a first opening of the first valve connected to the stack cooling line. [18] The structure according to claim 17, wherein when the first opening of the first valve is closed from a fully open state and when a second opening 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 for a predetermined period of time. [19] The structure according to claim 15, wherein, when the power of the fuel cell stack is less than a predetermined power, a first opening of the first valve connected to the stack cooling line is fully opened, and a second opening of the first valve connected to the electronic component cooling line is fully closed. [20] The structure according to claim 15, wherein, when the power of the fuel cell stack is equal to or greater than a predetermined power, the first valve is controlled so that a first opening of the first valve connected to the stack cooling line is fully closed and a second opening of the first valve connected to the electronic component cooling line is fully opened.

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