Fuel cell system and vehicle

Abstract

The utility model relates to the technical field of vehicles, and discloses a fuel cell system and a vehicle, the system comprises a first fuel cell stack, a second fuel cell stack, a hydrogen supply loop and an air supply loop, the hydrogen supply loop comprises a first hydrogen supply loop and a second hydrogen supply loop; the first hydrogen supply loop comprises a first shut-off valve and a first ejector, the hydrogen source is connected with a first gas inlet of the first ejector through the first shut-off valve, and a gas outlet of the first ejector is connected with a first inlet of the first fuel cell stack; the second hydrogen supply loop comprises a second shut-off valve and a second ejector, the hydrogen source is connected with a first gas inlet of the second ejector through the second shut-off valve, and a gas outlet of the second ejector is connected with a first inlet of the second fuel cell stack. Therefore, the utility model can meet the idle speed power constraint requirement and the voltage requirement of the whole vehicle, reduce the attenuation damage to the electric pile caused by a pile stopping method, reduce the hydrogen consumption and prolong the service life of the electric pile.

Description

Technical Field

[0001] This utility model relates to the field of vehicle technology, and in particular to a fuel cell system and a vehicle. Background Technology

[0002] Currently, high-power fuel cell systems have high idle power, which can easily lead to overcharging of the power battery. Conversely, lower idle power in high-power fuel cell systems means lower current density and higher average cell voltage, resulting in accelerated stack degradation. High-power fuel cell systems, characterized by high idle power under idling conditions, struggle to meet the upper limit requirements of vehicle idle power, and also exhibit high average cell voltage, further accelerating stack degradation and shortening fuel cell lifespan. Utility Model Content

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the first objective of this invention is to propose a fuel cell system that reduces the idling power of the fuel cell system to meet the vehicle's idling power constraints and voltage requirements. Under idling conditions, it switches from multi-stack operation to single-stack operation. Based on this, the current density can be increased to reduce the average single-cell voltage to meet the requirement of below 0.85V. Single-stack operation also ensures that the output power is below the vehicle's required idling power constraints. By using water injection to rest the stack, the generation of the hydrogen-air interface is avoided, reducing the degradation damage to the stack caused by the resting process, decreasing hydrogen consumption, and increasing the stack's lifespan.

[0004] The second objective of this utility model is to provide a vehicle.

[0005] To achieve the above objectives, the first aspect of this utility model provides a fuel cell system, comprising: a first fuel cell stack and a second fuel cell stack; a hydrogen supply circuit, including a first hydrogen supply circuit and a second hydrogen supply circuit; the first hydrogen supply circuit including a first shut-off valve and a first ejector, wherein a hydrogen source is connected to a first air inlet of the first ejector through the first shut-off valve, and an air outlet of the first ejector is connected to a first inlet of the first fuel cell stack; the second hydrogen supply circuit including a second shut-off valve and a second ejector, wherein a hydrogen source is connected to a first air inlet of the second ejector through the second shut-off valve, and an air outlet of the second ejector is connected to a first inlet of the second fuel cell stack; and an air supply circuit, including a first air compressor, a second air compressor, and an intercooler. The system includes a bypass valve, a third shut-off valve, a third solenoid directional valve, and a fourth solenoid directional valve. The air inlets of the first and second air compressors are connected to the atmospheric environment. The air outlet of the first air compressor is connected to the first air inlet of the intercooler. The first air outlet of the intercooler is connected to the first inlet of the fourth solenoid directional valve. The outlet of the fourth solenoid directional valve is connected to the first inlet of the third solenoid directional valve. The first outlet of the third solenoid directional valve is connected to the second inlet of the second fuel cell stack. The air outlet of the second air compressor is connected to the second air inlet of the intercooler. The second air outlet of the intercooler is connected to the air inlet of the bypass valve. The air outlet of the bypass valve is connected to the second inlet of the third solenoid directional valve via the third shut-off valve. The second outlet of the third solenoid directional valve is connected to the second inlet of the first fuel cell stack.

[0006] In addition, the fuel cell system described above according to this utility model may also have the following additional technical features:

[0007] Furthermore, the aforementioned fuel cell system also includes a water pump, the water pump's inlet being connected to a water tank, and the water pump's outlet being connected to the second inlet of a fourth electromagnetic reversing valve.

[0008] Furthermore, the hydrogen supply circuit also includes a hydrogen circulation circuit; the hydrogen circulation circuit includes a first electromagnetic reversing valve, a drain valve, a hydrogen circulation pump, and a second electromagnetic reversing valve. The first inlet of the first electromagnetic reversing valve is connected to the first outlet of the first fuel cell stack, the second inlet of the first electromagnetic reversing valve is connected to the first outlet of the second fuel cell stack, the outlet of the first electromagnetic reversing valve is connected to the inlet of the drain valve, the first outlet of the drain valve is connected to the inlet of the hydrogen circulation pump, the second outlet of the drain valve is connected to the water tank, the outlet of the hydrogen circulation pump is connected to the inlet of the second electromagnetic reversing valve, the first outlet of the second electromagnetic reversing valve is connected to the second air inlet of the first ejector, and the second outlet of the second electromagnetic reversing valve is connected to the second air inlet of the second ejector.

[0009] Furthermore, the air supply circuit also includes an air circulation circuit; the air circulation circuit includes a humidifier, a water distributor, a three-way valve, a back pressure valve, a fourth shut-off valve, a fifth shut-off valve, and a sixth shut-off valve; the third outlet of the intercooler is connected to the inlet of the three-way valve, the first outlet of the three-way valve is connected to the first inlet of the humidifier, the second outlet of the three-way valve is connected to the first inlet of the water distributor through the sixth shut-off valve, the first outlet of the humidifier is connected to the second inlet of the third solenoid reversing valve through the third shut-off valve, the second outlet of the first fuel cell stack is connected to the second inlet of the humidifier through the fifth shut-off valve, the second outlet of the second fuel cell stack is connected to the second inlet of the humidifier through the fourth shut-off valve, the second outlet of the humidifier is connected to the second inlet of the water distributor through the back pressure valve, the first outlet of the water distributor is connected to the water tank, and the second outlet of the water distributor is connected to the atmospheric environment.

[0010] Furthermore, the aforementioned fuel cell system also includes a switching circuit, which is disposed between the first fuel cell stack and the second fuel cell stack, and is used to control the operating status of the first fuel cell stack and the second fuel cell stack.

[0011] Furthermore, the switching circuit includes a DC-DC converter, a first switch, a second switch, and a third switch; the positive terminal of the DC-DC converter is selectively connected to the positive terminal of the first fuel cell stack or the positive terminal of the second fuel cell stack through the first switch, the negative terminal of the first fuel cell stack is selectively connected to the positive terminal of the first fuel cell stack through the second switch, and the negative terminal of the DC-DC converter is selectively connected to the negative terminal of the first fuel cell stack or the negative terminal of the second fuel cell stack through the third switch.

[0012] Furthermore, the aforementioned fuel cell system also includes a water-cooling circuit that runs through the first fuel cell stack and the second fuel cell stack. The water-cooling circuit is used to control the temperature of the first fuel cell stack or the second fuel cell stack, or both the first fuel cell stack and the second fuel cell stack.

[0013] Furthermore, the aforementioned fuel cell system further includes: a first flow meter, disposed between the first outlet of the third electromagnetic reversing valve and the second inlet of the second fuel cell stack, for detecting the first flow rate at the second inlet of the second fuel cell stack; a second flow meter, disposed between the second outlet of the third electromagnetic reversing valve and the second inlet of the first fuel cell stack, for detecting the second flow rate at the second inlet of the first fuel cell stack; a third flow meter, disposed between the second outlet of the second fuel cell stack and the second inlet of the humidifier, for detecting the third flow rate at the second outlet of the second fuel cell stack; and a fourth flow meter, disposed between the second outlet of the first fuel cell stack and the second inlet of the humidifier, for detecting the fourth flow rate at the second outlet of the first fuel cell stack.

[0014] The fuel cell system according to this utility model includes: a first fuel cell stack and a second fuel cell stack; a hydrogen supply circuit, which includes a first hydrogen supply circuit and a second hydrogen supply circuit; the first hydrogen supply circuit includes a first shut-off valve and a first ejector, wherein a hydrogen source is connected to a first air inlet of the first ejector through the first shut-off valve, and an air outlet of the first ejector is connected to a first inlet of the first fuel cell stack; the second hydrogen supply circuit includes a second shut-off valve and a second ejector, wherein a hydrogen source is connected to a first air inlet of the second ejector through the second shut-off valve, and an air outlet of the second ejector is connected to a first inlet of the second fuel cell stack; and an air supply circuit, which includes a first air compressor, a second air compressor, an intercooler, a bypass valve, and a third... The system includes a shut-off valve, a third solenoid directional valve, and a fourth solenoid directional valve. The air inlets of the first and second air compressors are connected to the atmospheric environment. The air outlet of the first air compressor is connected to the first air inlet of the intercooler. The first air outlet of the intercooler is connected to the first inlet of the fourth solenoid directional valve. The outlet of the fourth solenoid directional valve is connected to the first inlet of the third solenoid directional valve. The first outlet of the third solenoid directional valve is connected to the second inlet of the second fuel cell stack. The air outlet of the second air compressor is connected to the second air inlet of the intercooler. The second air outlet of the intercooler is connected to the air inlet of the bypass valve. The air outlet of the bypass valve is connected to the second inlet of the third solenoid directional valve via the third shut-off valve. The second outlet of the third solenoid directional valve is connected to the second inlet of the first fuel cell stack. Therefore, this system reduces the idling power of the fuel cell system to meet the vehicle's idling power constraints and voltage requirements. Under idling conditions, it switches from multi-stack operation to single-stack operation. On this basis, the current density can be increased to reduce the average single-cell voltage to meet the requirement of below 0.85V. Single-stack operation also ensures that the output power is lower than the vehicle's required idling power constraints. By injecting water to rest the stack, the generation of the hydrogen-air interface is avoided, reducing the damage to the stack caused by the resting process, reducing hydrogen consumption, and improving the stack's service life.

[0015] To achieve the above objectives, a second aspect of this utility model provides a vehicle including the aforementioned fuel cell system.

[0016] According to the present invention, the vehicle utilizes the aforementioned fuel cell system to reduce the idling power of the fuel cell system, thereby meeting the vehicle's idling power constraints and voltage requirements. Under idling conditions, the system switches from multi-stack operation to single-stack operation. Based on this, the current density can be increased to reduce the average single-cell voltage to meet the requirement of below 0.85V. Single-stack operation also ensures that the output power is lower than the vehicle's required idling power constraints. By injecting water to rest the stack, the generation of the hydrogen-air interface is avoided, reducing the damage to the stack caused by the resting process, reducing hydrogen consumption, and improving the stack's service life.

[0017] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] Figure 1 This is a block diagram of a fuel cell system according to some embodiments of the present invention;

[0019] Figure 2 This is a block diagram of a switching circuit according to some embodiments of the present invention;

[0020] Figure 3 This is a block diagram of a vehicle according to some embodiments of the present invention.

[0021] Explanation of reference numerals in the attached figures:

[0022] 100-Fuel cell system, 8-First fuel cell stack, 7-Second fuel cell stack, 4-First shut-off valve, 6-First ejector, 1-Hydrogen source, 3-Second shut-off valve, 5-Second ejector, 9-First solenoid directional valve, 10-Drain valve, 11-Hydrogen circulation pump, 12-Second solenoid directional valve, 2-Proportional valve, 28-First air compressor, 15-Second air compressor, 14-Intercooler, 18-Bypass valve, 19-Third shut-off valve, 20-Third Solenoid directional valve, 29-Fourth solenoid directional valve, 17-Humidifier, 25-Water distributor, 16-Three-way valve, 23-Back pressure valve, 21-Fourth shut-off valve, 22-Fifth shut-off valve, 24-Sixth shut-off valve, 27-Water pump, 26-Water tank, 35-DC converter, 36-First switch, 38-Second switch, 37-Third switch, 34-Water cooling circuit, 30-First flow meter, 31-Second flow meter, 32-Third flow meter and 33-Fourth flow meter. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0024] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this utility model should have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "first," "second," and similar words used in the embodiments of this utility model do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0025] As mentioned in the background section, currently, high-power fuel cell systems have relatively high idle power, which can easily lead to overcharging of the power battery. Conversely, lower idle power in high-power fuel cell systems means lower current density and higher average cell voltage, resulting in accelerated stack degradation. Therefore, manufacturers specify that the idle power of the fuel cell system cannot exceed a certain value, and the average cell voltage cannot exceed a certain value.

[0026] High-power fuel cell systems have high idling power under idling conditions, which makes it difficult to meet the upper limit requirements of the vehicle's idling power. They also have high average single-cell voltage, which accelerates the degradation of the fuel cell stack and reduces the lifespan of the fuel cell.

[0027] In the process of developing this utility model, the applicant discovered that fuel cell systems typically exhibit a high potential during idling. For high-power fuel cells, the average voltage per cell is relatively high, which easily accelerates the degradation of the fuel cell stack. In related technologies, using a high potential for a short period exacerbates stack degradation and severely impacts fuel cell lifespan.

[0028] Therefore, this invention reduces the idling power of the fuel cell system to meet the vehicle's idling power constraints and voltage requirements. Under idling conditions, it switches from multi-stack operation to single-stack operation. On this basis, the current density can be increased to reduce the average single-cell voltage to meet the requirement of below 0.85V. Single-stack operation also ensures that the output power is lower than the vehicle's required idling power constraints. By injecting water to rest the stack, the generation of the hydrogen-air interface is avoided, reducing the damage to the stack caused by the resting process, reducing hydrogen consumption, and improving the stack's service life.

[0029] The fuel cell system and vehicle proposed in the embodiments of this utility model are described below with reference to the accompanying drawings.

[0030] refer to Figure 1 This is a block diagram of a fuel cell system according to some embodiments of the present invention.

[0031] The fuel cell system 100 of this utility model includes a first fuel cell stack 8, a second fuel cell stack 7, a hydrogen supply circuit, and an air supply circuit. The number of fuel cell stacks is at least two, and the fuel cell stacks can be connected in parallel.

[0032] The hydrogen supply circuit includes a first hydrogen supply circuit and a second hydrogen supply circuit. The first hydrogen supply circuit includes a first shut-off valve 4 and a first ejector 6. The hydrogen source 1 is connected to the first air inlet of the first ejector 6 through the first shut-off valve 4. The hydrogen source 1 is used to supply hydrogen. The air outlet of the first ejector 6 is connected to the first inlet of the first fuel cell stack 8.

[0033] The second hydrogen supply circuit includes a second shut-off valve 3 and a second ejector 5. The hydrogen source 1 is connected to the first inlet of the second ejector 5 through the second shut-off valve 3, and the outlet of the second ejector 5 is connected to the first inlet of the second fuel cell stack 7.

[0034] The hydrogen supply circuit also includes a hydrogen circulation circuit, which includes a first electromagnetic reversing valve 9, a drain valve 10, a hydrogen circulation pump 11, and a second electromagnetic reversing valve 12. The first inlet of the first electromagnetic reversing valve 9 is connected to the first outlet of the first fuel cell stack 8, the second inlet of the first electromagnetic reversing valve 9 is connected to the first outlet of the second fuel cell stack 7, the outlet of the first electromagnetic reversing valve 9 is connected to the inlet of the drain valve 10, the first outlet of the drain valve 10 is connected to the inlet of the hydrogen circulation pump 11, the second outlet of the drain valve 10 is connected to the water tank 26, the outlet of the hydrogen circulation pump 11 is connected to the inlet of the second electromagnetic reversing valve 12, the first outlet of the second electromagnetic reversing valve 12 is connected to the second air inlet of the first ejector 6, and the second outlet of the second electromagnetic reversing valve 12 is connected to the second air inlet of the second ejector 5. The second electromagnetic reversing valve 12 serves as a preliminary working step for the reactor shutdown process, preparing for the shutdown operation.

[0035] The hydrogen supply circuit also includes a proportional valve 2, the inlet of which is connected to the hydrogen source 1, and the outlet of which is connected to the inlet of the first shut-off valve 4 and the second shut-off valve 3, respectively.

[0036] The air supply circuit includes a first air compressor 28, a second air compressor 15, an intercooler 14, a bypass valve 18, a third shut-off valve 19, a third solenoid directional valve 20, and a fourth solenoid directional valve 29. The air inlet of the first air compressor 28 is connected to the atmospheric environment, the air outlet of the first air compressor 28 is connected to the first air inlet of the intercooler 14, the first air outlet of the intercooler 14 is connected to the first inlet of the fourth solenoid directional valve 29, the outlet of the fourth solenoid directional valve 29 is connected to the first inlet of the third solenoid directional valve 20, and the first outlet of the third solenoid directional valve 20 is connected to the second inlet of the second fuel cell stack 7.

[0037] The air inlet of the second air compressor 15 is connected to the atmospheric environment, the air outlet of the second air compressor 15 is connected to the second air inlet of the intercooler 14, the second air outlet of the intercooler 14 is connected to the air inlet of the bypass valve 18, the air outlet of the bypass valve 18 is connected to the second inlet of the third solenoid directional valve 20 through the third shut-off valve 19, and the second outlet of the third solenoid directional valve 20 is connected to the second inlet of the first fuel cell stack 8.

[0038] The air supply circuit also includes an air circulation circuit, which includes a humidifier 17, a water distributor 25, a three-way valve 16, a back pressure valve 23, a fourth shut-off valve 21, a fifth shut-off valve 22, and a sixth shut-off valve 24. The third outlet of the intercooler 14 is connected to the inlet of the three-way valve 16. The first outlet of the three-way valve 16 is connected to the first inlet of the humidifier 17. The second outlet of the three-way valve 16 is connected to the first inlet of the water distributor 25 via the sixth shut-off valve 24. The first outlet of the humidifier 17 is connected to the second inlet of the third solenoid directional valve 20 via the third shut-off valve 19. The second outlet of the first fuel cell stack 8 is connected to the second inlet of the humidifier 17 via the fifth shut-off valve 22. The second outlet of the second fuel cell stack 7 is connected to the second inlet of the humidifier 17 via the fourth shut-off valve 21. The second outlet of the humidifier 17 is connected to the second inlet of the water distributor 25 via the back pressure valve 23. The first outlet of the water distributor 25 is connected to the water tank 26, and the second outlet of the water distributor 25 is connected to the atmospheric environment.

[0039] The fuel cell system 100 also includes a water pump 27, the inlet of which is connected to a water tank 26, and the outlet of which is connected to the second inlet of a fourth solenoid directional valve 29. The water pump 27 is used to draw water stored in the water tank 26.

[0040] The purging function can be achieved by turning on the first air compressor 28, turning off the water pump 27, and changing the opening of the fourth electromagnetic reversing valve 29, ultimately realizing the shutdown function of the fuel cell stack.

[0041] The fuel cell system 100 also includes a switching circuit, which is located between the first fuel cell stack 8 and the second fuel cell stack 7, and is used to control the operating state of the first fuel cell stack 8 and the second fuel cell stack 7 (i.e., to control whether the operating state of the first fuel cell stack 8 and the second fuel cell stack 7 is a standby state).

[0042] refer to Figure 2 The diagram below is a block diagram of a switching circuit according to some embodiments of the present invention. The switching circuit includes a DC-DC converter 35, a first switch 36, a second switch 38, and a third switch 37. The positive terminal of the DC-DC converter 35 is selectively connected to the positive terminal of the first fuel cell stack 8 or the positive terminal of the second fuel cell stack 7 through the first switch 36. The negative terminal of the first fuel cell stack 8 is selectively connected to the positive terminal of the first fuel cell stack 8 through the second switch 38. The negative terminal of the DC-DC converter 35 is selectively connected to the negative terminal of the first fuel cell stack 8 or the negative terminal of the second fuel cell stack 7 through the third switch 37.

[0043] Continue to refer to Figure 2 When both the first fuel cell stack 8 and the second fuel cell stack 7 are operating (i.e., in a continuous stack operation), the first switch 36 is connected to the positive terminal of the first fuel cell stack 8, the second switch 38 is connected to the negative terminal of the second fuel cell stack 7, and the third switch 37 is in a closed state. When only one stack is required to operate, the third switch 37 is in an open state, the first switch 36 is connected to the positive terminal of the operating stack, and the second switch 38 is connected to the negative terminal of the operating stack.

[0044] The fuel cell system 100 also includes a water-cooling circuit 34, which runs through the first fuel cell stack 8 and the second fuel cell stack 7. The water-cooling circuit 34 is used to control the temperature of the first fuel cell stack 8 or the second fuel cell stack 7, or both of the first fuel cell stack 8 and the second fuel cell stack 7, so as to cool down the first fuel cell stack 8 or the second fuel cell stack 7 when they are at high temperatures.

[0045] Even after the fuel cell stack is idle, the water-cooling circuit 34 continues to pump coolant into either the first fuel cell stack 8 or the second fuel cell stack 7, or both, with the flow rate adjusted by a thermostat. The coolant output from the working stack provides heat to the idle fuel cell stack via the water-cooling circuit 34, effectively preventing icing in the idle fuel cell stack.

[0046] The fuel cell system 100 also includes a first flow meter 30, a second flow meter 31, a third flow meter 32, and a fourth flow meter 3333. The first flow meter 30 is disposed between the first outlet of the third electromagnetic reversing valve 20 and the second inlet of the second fuel cell stack 7, and is used to detect the first flow rate at the second inlet of the second fuel cell stack 7. The second flow meter 31 is disposed between the second outlet of the third electromagnetic reversing valve 20 and the second inlet of the first fuel cell stack 8, and is used to detect the second flow rate at the second inlet of the first fuel cell stack 8. The third flow meter 32 is disposed between the second outlet of the second fuel cell stack 7 and the second inlet of the humidifier 17, and is used to detect the third flow rate at the second outlet of the second fuel cell stack 7. The fourth flow meter 3333 is disposed between the second outlet of the first fuel cell stack 8 and the second inlet of the humidifier 17, and is used to detect the fourth flow rate at the second outlet of the first fuel cell stack 8.

[0047] Therefore, the fuel cell system 100 of this utility model includes a first fuel cell stack 8, a second fuel cell stack 7, a first shut-off valve 4, a first ejector 6, a hydrogen source 1, a second shut-off valve 3, a second ejector 5, a first solenoid directional valve 9, a drain valve 10, a hydrogen circulation pump 11, a second solenoid directional valve 12, a proportional valve 2, a first air compressor 28, a second air compressor 15, an intercooler 14, a bypass valve 18, a third shut-off valve 19, a third solenoid directional valve 20, a fourth solenoid directional valve 29, a humidifier 17, a water distributor 25, a three-way valve 16, a back pressure valve 23, a fourth shut-off valve 21, a fifth shut-off valve 22, a sixth shut-off valve 24, a water pump 27, a water tank 26, a DC-DC converter 35, a first switch 36, a second switch 38, a third switch 37, a water cooling circuit 34, a first flow meter 30, a second flow meter 31, a third flow meter 32, and a fourth flow meter 3333.

[0048] Hydrogen gas enters hydrogen source 1 and proportional valve 2, then enters second shut-off valve 3 and first shut-off valve 4 respectively, and passes through second ejector 5 and first ejector 6 to enter first fuel cell stack 8 and second fuel cell stack 7 respectively. The remaining mixed gas enters drain valve 10 through first solenoid reversing valve 9, liquid water enters water tank 26, and the gas returns to first ejector 6 and second ejector 5 for secondary flow through hydrogen circulation pump 11 and second solenoid reversing valve 12.

[0049] Air passes through the atmosphere via the first air compressor 28 and the second air compressor 15, entering the intercooler 14 and then the three-way valve 16 and the bypass valve 18. Air entering the three-way valve 16 can either enter the water distributor 25 through the sixth shut-off valve 24, or it can merge with the humidifier 17 and the bypass valve 18 interface, then pass through the third shut-off valve 19 and the third solenoid directional valve 20 to enter the first fuel cell stack 8 and the second fuel cell stack 7. Remaining gas can enter the fourth shut-off valve 21 and the fifth shut-off valve 22, then merge into the humidifier 17 and pass through the back pressure valve 23 to enter the water distributor 25. Liquid water enters the water tank 26, and some gaseous gas is discharged into the atmosphere. Water in the water tank 26 can be pumped into a specific fuel cell stack via the water pump 27 and the fourth solenoid directional valve 29, depending on the operating conditions.

[0050] In summary, the fuel cell system according to the embodiments of this utility model includes: a first fuel cell stack and a second fuel cell stack; a hydrogen supply circuit, which includes a first hydrogen supply circuit and a second hydrogen supply circuit; the first hydrogen supply circuit includes a first shut-off valve and a first ejector, wherein a hydrogen source is connected to a first air inlet of the first ejector through the first shut-off valve, and an air outlet of the first ejector is connected to a first inlet of the first fuel cell stack; the second hydrogen supply circuit includes a second shut-off valve and a second ejector, wherein a hydrogen source is connected to a first air inlet of the second ejector through the second shut-off valve, and an air outlet of the second ejector is connected to a first inlet of the second fuel cell stack; and an air supply circuit, which includes a first air compressor, a second air compressor, an intercooler, and a bypass. The system includes a valve, a third shut-off valve, a third solenoid directional valve, and a fourth solenoid directional valve; the air inlets of the first and second air compressors are connected to the atmospheric environment; the air outlet of the first air compressor is connected to the first air inlet of the intercooler; the first air outlet of the intercooler is connected to the first inlet of the fourth solenoid directional valve; the outlet of the fourth solenoid directional valve is connected to the first inlet of the third solenoid directional valve; the first outlet of the third solenoid directional valve is connected to the second inlet of the second fuel cell stack; the air outlet of the second air compressor is connected to the second air inlet of the intercooler; the second air outlet of the intercooler is connected to the air inlet of the bypass valve; the air outlet of the bypass valve is connected to the second inlet of the third solenoid directional valve via the third shut-off valve; and the second outlet of the third solenoid directional valve is connected to the second inlet of the first fuel cell stack. Therefore, this system reduces the idling power of the fuel cell system to meet the vehicle's idling power constraints and voltage requirements. Under idling conditions, it switches from multi-stack operation to single-stack operation. On this basis, the current density can be increased to reduce the average single-cell voltage to meet the requirement of below 0.85V. Single-stack operation also ensures that the output power is lower than the vehicle's required idling power constraints. By injecting water to rest the stack, the generation of the hydrogen-air interface is avoided, reducing the damage to the stack caused by the resting process, reducing hydrogen consumption, and improving the stack's service life.

[0051] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this utility model also provides a vehicle, such as... Figure 3 As shown, vehicle 700 includes the aforementioned fuel cell system 100.

[0052] According to the vehicle of this utility model embodiment, the above-described fuel cell system reduces the idling power of the fuel cell system to meet the vehicle's idling power constraints and voltage requirements. Under idling conditions, the system switches from multi-stack operation to single-stack operation. Based on this, the current density can be increased to reduce the average single-cell voltage to meet the requirement of below 0.85V. Single-stack operation also ensures that the output power is lower than the vehicle's required idling power constraints. By injecting water to rest the stack, the generation of the hydrogen-air interface is avoided, reducing the damage to the stack caused by the resting process, reducing hydrogen consumption, and improving the stack's service life.

[0053] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this utility model should have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "first," "second," and similar words used in the embodiments of this utility model do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0054] While the spirit and principles of this invention have been described with reference to several specific embodiments, it should be understood that this invention is not limited to the disclosed specific embodiments, and the division of aspects does not imply that features in these aspects cannot be combined for benefit; such division is merely for ease of description. This invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the appended claims is to be interpreted in the broadest sense, thereby encompassing all such modifications and equivalent structures and functions.

Claims

1. A fuel cell system, characterized in that, include: The first fuel cell stack (8) and the second fuel cell stack (7); The hydrogen supply circuit includes a first hydrogen supply circuit and a second hydrogen supply circuit. The first hydrogen supply circuit includes a first shut-off valve (4) and a first ejector (6). The hydrogen source (1) is connected to the first inlet of the first ejector (6) through the first shut-off valve (4), and the outlet of the first ejector (6) is connected to the first inlet of the first fuel cell stack (8). The second hydrogen supply circuit includes a second shut-off valve (3) and a second ejector (5). The hydrogen source (1) is connected to the first inlet of the second ejector (5) through the second shut-off valve (3), and the outlet of the second ejector (5) is connected to the first inlet of the second fuel cell stack (7). An air supply circuit includes a first air compressor (28), a second air compressor (15), an intercooler (14), a bypass valve (18), a third shut-off valve (19), a third solenoid directional valve (20), and a fourth solenoid directional valve (29). The air inlets of the first air compressor (28) and the second air compressor (15) are connected to the atmospheric environment. The air outlet of the first air compressor (28) is connected to the first air inlet of the intercooler (14). The first air outlet of the intercooler (14) is connected to the first inlet of the fourth solenoid directional valve (29). The outlet of the fourth solenoid directional valve (29) is connected to the first inlet of the intercooler (14). The first inlet of the third electromagnetic reversing valve (20) is connected, and the first outlet of the third electromagnetic reversing valve (20) is connected to the second inlet of the second fuel cell stack (7); the outlet of the second air compressor (15) is connected to the second inlet of the intercooler (14), the second outlet of the intercooler (14) is connected to the inlet of the bypass valve (18), the outlet of the bypass valve (18) is connected to the second inlet of the third electromagnetic reversing valve (20) through the third shut-off valve (19), and the second outlet of the third electromagnetic reversing valve (20) is connected to the second inlet of the first fuel cell stack (8).

2. The fuel cell system according to claim 1, characterized in that, It also includes a water pump (27), the inlet of which is connected to the water tank (26), and the outlet of which is connected to the second inlet of the fourth electromagnetic reversing valve (29).

3. The fuel cell system according to claim 2, characterized in that, The hydrogen supply circuit also includes a hydrogen circulation circuit; The hydrogen circulation loop includes a first electromagnetic reversing valve (9), a drain valve (10), a hydrogen circulation pump (11), and a second electromagnetic reversing valve (12). The first inlet of the first electromagnetic reversing valve (9) is connected to the first outlet of the first fuel cell stack (8), the second inlet of the first electromagnetic reversing valve (9) is connected to the first outlet of the second fuel cell stack (7), the outlet of the first electromagnetic reversing valve (9) is connected to the inlet of the drain valve (10), the first outlet of the drain valve (10) is connected to the inlet of the hydrogen circulation pump (11), the second outlet of the drain valve (10) is connected to the water tank (26), the outlet of the hydrogen circulation pump (11) is connected to the inlet of the second electromagnetic reversing valve (12), the first outlet of the second electromagnetic reversing valve (12) is connected to the second air inlet of the first ejector (6), and the second outlet of the second electromagnetic reversing valve (12) is connected to the second air inlet of the second ejector (5).

4. The fuel cell system according to claim 2, characterized in that, The air supply circuit also includes an air circulation circuit; The air circulation loop includes a humidifier (17), a water distributor (25), a three-way valve (16), a back pressure valve (23), a fourth shut-off valve (21), a fifth shut-off valve (22), and a sixth shut-off valve (24); the third outlet of the intercooler (14) is connected to the inlet of the three-way valve (16), the first outlet of the three-way valve (16) is connected to the first inlet of the humidifier (17), the second outlet of the three-way valve (16) is connected to the first inlet of the water distributor (25) through the sixth shut-off valve (24), and the first outlet of the humidifier (17) is connected to the third shut-off valve (19). The second inlet of the third electromagnetic reversing valve (20) is connected, the second outlet of the first fuel cell stack (8) is connected to the second inlet of the humidifier (17) through the fifth shut-off valve (22), the second outlet of the second fuel cell stack (7) is connected to the second inlet of the humidifier (17) through the fourth shut-off valve (21), the second outlet of the humidifier (17) is connected to the second inlet of the water distributor (25) through the back pressure valve (23), the first outlet of the water distributor (25) is connected to the water tank (26), and the second outlet of the water distributor (25) is connected to the atmospheric environment.

5. The fuel cell system according to claim 2, characterized in that, It also includes a switching circuit, which is disposed between the first fuel cell stack (8) and the second fuel cell stack (7) for controlling the working state of the first fuel cell stack (8) and the second fuel cell stack (7).

6. The fuel cell system according to claim 5, characterized in that, The switching circuit includes a DC-DC converter (35), a first switch (36), a second switch (38), and a third switch (37). The positive terminal of the DC-DC converter (35) is selectively connected to the positive terminal of the first fuel cell stack (8) or the positive terminal of the second fuel cell stack (7) through the first switch (36). The negative terminal of the first fuel cell stack (8) is selectively connected to the positive terminal of the first fuel cell stack (8) through the second switch (38). The negative terminal of the DC-DC converter (35) is selectively connected to the negative terminal of the first fuel cell stack (8) or the negative terminal of the second fuel cell stack (7) through the third switch (37).

7. The fuel cell system according to claim 2, characterized in that, It also includes a water-cooling circuit (34), which runs through the first fuel cell stack (8) and the second fuel cell stack (7). The water-cooling circuit (34) is used to control the temperature of the first fuel cell stack (8) or the second fuel cell stack (7) or the first fuel cell stack (8) and the second fuel cell stack (7).

8. The fuel cell system according to claim 4, characterized in that, Also includes: The first flow meter (30) is disposed between the first outlet of the third electromagnetic reversing valve (20) and the second inlet of the second fuel cell stack (7) for detecting the first flow rate at the second inlet of the second fuel cell stack (7); The second flow meter (31) is disposed between the second outlet of the third electromagnetic reversing valve (20) and the second inlet of the first fuel cell stack (8) for detecting the second flow rate at the second inlet of the first fuel cell stack (8); The third flow meter (32) is disposed between the second outlet of the second fuel cell stack (7) and the second inlet of the humidifier (17) for detecting the third flow rate at the second outlet of the second fuel cell stack (7); A fourth flow meter (33) is disposed between the second outlet of the first fuel cell stack (8) and the second inlet of the humidifier (17) for detecting the fourth flow rate at the second outlet of the first fuel cell stack (8).

9. A vehicle, characterized in that, Including the fuel cell system as described in any one of claims 1-8.

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