Control method and device of fuel cell system

Abstract

The invention relates to the technical field of vehicles, and discloses a control method and device for a fuel cell system, and the method comprises the steps: determining whether the fuel cell system is in an idling condition or not; determining whether the first fuel cell stack and the second fuel cell stack are both in a working state in response to the condition that the fuel cell system is in the idling working condition; responding to the fact that the first fuel cell stack and the second fuel cell stack are both in a working state; a first shut-off valve, a second shut-off valve, a water pump, a first switch, a second switch, a third switch, a first electromagnetic directional valve, a second electromagnetic directional valve, a third electromagnetic directional valve and a fourth electromagnetic directional valve are controlled according to the residual life of the first fuel cell stack and the second fuel cell stack; the first fuel cell stack or the second fuel cell stack is in a non-working state. Therefore, the attenuation damage to the electric pile caused by a pile stopping method can be reduced, the hydrogen consumption is reduced, and the service life of the electric pile is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles, and in particular, to a control method for a fuel cell system and a control device for a fuel cell system. Background Art

[0002] Currently, the idle power of high-power fuel cell systems is relatively high, which easily causes the problem of overcharging of the power battery. At the same time, the lower the idle power of high-power fuel cell systems, the lower the current density and the higher the average single-cell voltage, resulting in an aggravated attenuation of the fuel cell stack. Under idle conditions, high-power fuel cell systems have the characteristics of high idle power, making it difficult to meet the upper limit requirements of the vehicle's idle power. At the same time, they also have the characteristic of high average single-cell voltage, accelerating the attenuation of the fuel cell stack and shortening the service life of the fuel cell. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems in the related art to some extent. To this end, the first object of the present invention is to propose a control method for a fuel cell system, which reduces the idle power of the fuel cell system to meet the vehicle's idle power constraint requirements and voltage requirements. Under idle conditions, the operation changes from multiple fuel cell stacks to a single fuel cell stack. On this basis, the current density can be increased to reduce the average single-cell voltage to be lower than 0.85V. The operation of a single fuel cell stack also ensures that the output power is lower than the idle power constraint requirements of the vehicle. By means of water injection and stack shutdown, the generation of the hydrogen-air interface is avoided, the attenuation damage of the stack shutdown method to the fuel cell stack is reduced, the hydrogen consumption is reduced, and the service life of the fuel cell stack is extended.

[0004] The second object of the present invention is to propose a control device for a fuel cell system.

[0005] To achieve the above object, a control method for a fuel cell system according to an embodiment of the first aspect of the present invention includes: determining whether the fuel cell system is in an idle condition; in response to the fuel cell system being in an idle condition, determining whether the first fuel cell stack and the second fuel cell stack are both in a working state; in response to both the first fuel cell stack and the second fuel cell stack being in a working state, controlling a first shut-off valve, a second shut-off valve, a water pump, a first switch, a second switch, a third switch, a first electromagnetic directional valve, a second electromagnetic directional valve, a third electromagnetic directional valve, and a fourth electromagnetic directional valve according to the remaining service lives of the first fuel cell stack and the second fuel cell stack, so that either the first fuel cell stack or the second fuel cell stack is in a non-working state.

[0006] In addition, the control method for a fuel cell system according to the above embodiment of the present invention may further have the following additional technical features:

[0007] According to some embodiments of the present invention, before determining whether the fuel cell system is in an idle condition, the method further includes: controlling to open the first shut-off valve, the second shut-off valve, the third shut-off valve, the fourth shut-off valve, and the fifth shut-off valve, controlling the first electromagnetic reversing valve, the second electromagnetic reversing valve, the third electromagnetic reversing valve, and the fourth electromagnetic reversing valve to be in a second preset position, and controlling the water pump to close.

[0008] According to some embodiments of the present invention, controlling the first shut-off valve, the second shut-off valve, the water pump, the first switch, the second switch, the third switch, the first electromagnetic reversing valve, the second electromagnetic reversing valve, the third electromagnetic reversing valve, and the fourth electromagnetic reversing valve according to the remaining service lives of the first fuel cell stack and the second fuel cell stack, so that the first fuel cell stack or the second fuel cell stack is in a non-operating state, includes: controlling the fourth electromagnetic reversing valve to be in a third preset position, controlling the water pump to open, and controlling the third switch to disconnect; calculating a first remaining service life of the first fuel cell stack and a second remaining service life of the second fuel cell stack, and comparing the magnitudes of the first remaining service life and the second remaining service life; in response to the first remaining service life being lower than the second remaining service life, controlling the positive pole of the DC converter to be connected to the positive pole of the second fuel cell stack through the first switch, and the negative pole of the DC converter to be connected to the negative pole of the second fuel cell stack through the third switch, controlling the first electromagnetic reversing valve and the second electromagnetic reversing valve to be in a third preset position, the third electromagnetic reversing valve to be in a first preset position, and controlling the first shut-off valve to close.

[0009] According to some embodiments of the present invention, the above method further includes: in response to the second remaining service life being lower than the first remaining service life, controlling the positive pole of the DC converter to be connected to the positive pole of the first fuel cell stack through the first switch, and the negative pole of the DC converter to be connected to the negative pole of the first fuel cell stack through the third switch, controlling the first electromagnetic reversing valve and the second electromagnetic reversing valve to be in a first preset position, the third electromagnetic reversing valve to be in a third preset position, and controlling the second shut-off valve to close.

[0010] According to some embodiments of the present invention, the above method further includes: determining whether the difference between the second flow rate detected by the second flowmeter and the fourth flow rate detected by the fourth flowmeter is less than a preset difference; in response to the difference between the second flow rate and the fourth flow rate being less than the preset difference, controlling the fifth shut-off valve to close, controlling the water pump to stop working, and controlling the fourth electromagnetic reversing valve to be in a second preset position.

[0011] According to some embodiments of the present invention, the above method further includes: determining whether the difference between the first flow rate detected by the first flowmeter and the third flow rate detected by the third flowmeter is less than a preset difference; in response to the difference between the first flow rate and the third flow rate being less than the preset difference, controlling the fourth shut-off valve to close, controlling the water pump to stop working, and controlling the fourth electromagnetic reversing valve to be in a second preset position.

[0012] According to some embodiments of the present invention, the above method further includes: in response to the fuel cell system being in a non-idle working condition, determining whether both the first fuel cell stack and the second fuel cell stack are in a working state; in response to the first fuel cell stack or the second fuel cell stack being in a non-working state, controlling the first air compressor to work; controlling the first shut-off valve, the second shut-off valve, the fourth shut-off valve, the fifth shut-off valve, the first switch, the second switch, and the third switch according to the working power of the first fuel cell stack and the second fuel cell stack, and controlling the first electromagnetic reversing valve, the second electromagnetic reversing valve, and the fourth electromagnetic reversing valve, so that both the first fuel cell stack and the second fuel cell stack are in a working state.

[0013] According to some embodiments of the present invention, controlling the first shut-off valve, the second shut-off valve, the fourth shut-off valve, the fifth shut-off valve, the first switch, the second switch, and the third switch according to the working power of the first fuel cell stack and the second fuel cell stack, and controlling the first electromagnetic reversing valve, the second electromagnetic reversing valve, and the fourth electromagnetic reversing valve, so that both the first fuel cell stack and the second fuel cell stack are in a working state, includes: determining the fuel cell stack in a non-working state according to the working power of the first fuel cell stack and the second fuel cell stack; in response to the first fuel cell stack being in a non-working state, controlling the first shut-off valve and the fifth shut-off valve to open, and controlling the first electromagnetic reversing valve and the second electromagnetic reversing valve to be in the second preset position, and the fourth electromagnetic reversing valve to be in the first preset position; obtaining the single-cell voltage data and the water content of the first fuel cell stack, and determining whether the first fuel cell stack is in a flooded state according to the water content of the first fuel cell stack; in response to the first fuel cell stack not being in a flooded state, connecting the positive pole of the DC converter to the positive pole of the first fuel cell stack through the first switch, connecting the negative pole of the DC converter to the negative pole of the second fuel cell stack through the third switch, and closing the second switch; determining whether the single-cell voltage data of the first fuel cell stack is normal; in response to the single-cell voltage data of the first fuel cell stack being normal, controlling the third electromagnetic steering valve to be in the second preset position, and the fourth electromagnetic steering valve to be in the second preset position, and controlling the first air compressor to stop working.

[0014] According to some embodiments of the present invention, the above method further includes: in response to the second fuel cell stack being in a non-operating state, controlling the second shut-off valve and the fourth shut-off valve to open, controlling the first electromagnetic reversing valve and the second electromagnetic reversing valve to be in a second preset position, and the fourth electromagnetic reversing valve to be in a first preset position; obtaining the single-cell voltage data and the water content of the second fuel cell stack, and determining whether the second fuel cell stack is in a flooded state according to the water content of the second fuel cell stack; in response to the second fuel cell stack not being in a flooded state, controlling the positive pole of the DC converter to be connected to the positive pole of the first fuel cell stack through the first switch, the negative pole of the DC converter to be connected to the negative pole of the second fuel cell stack through the third switch, and the second switch to be closed; determining whether the single-cell voltage data of the second fuel cell stack is normal; in response to the single-cell voltage data of the second fuel cell stack being normal, controlling the third electromagnetic steering valve to be in the second preset position and the fourth electromagnetic steering valve to be in the second preset position, and controlling the first air compressor to stop working.

[0015] A method for controlling the operating conditions of a fuel cell system according to an embodiment of the present invention includes: determining whether the fuel cell system is in an idle operating condition; in response to the fuel cell system being in an idle operating condition, determining whether both the first fuel cell stack and the second fuel cell stack are in an operating state; in response to both the first fuel cell stack and the second fuel cell stack being in an operating state, controlling the first shut-off valve, the second shut-off valve, the water pump, the first switch, the second switch, the third switch, the first electromagnetic reversing valve, the second electromagnetic reversing valve, the third electromagnetic reversing valve, and the fourth electromagnetic reversing valve according to the remaining service lives of the first fuel cell stack and the second fuel cell stack, so that either the first fuel cell stack or the second fuel cell stack is in a non-operating state. Thus, this method reduces the idle power of the fuel cell system to meet the vehicle idle power constraint requirements and voltage requirements. Under the idle operating condition, the operation changes from multiple fuel cell stacks working to a single fuel cell stack working. On this basis, the current density can be increased to reduce the average single-cell voltage to be lower than 0.85V. The single fuel cell stack working can also ensure that the output power is lower than the vehicle idle power constraint requirements. By the method of injecting water to suspend the operation of the fuel cell stack, the generation of the hydrogen-air interface is avoided, the attenuation damage of the fuel cell stack caused by the method of suspending the operation is reduced, the hydrogen consumption is reduced, and the service life of the fuel cell stack is increased.

[0016] The second object of the present invention is to propose a control device for a fuel cell system, which reduces the idle power of the fuel cell system to meet the vehicle idle power constraint requirements and voltage requirements. Under the idle operating condition, the operation changes from multiple fuel cell stacks working to a single fuel cell stack working. On this basis, the current density can be increased to reduce the average single-cell voltage to be lower than 0.85V. The single fuel cell stack working can also ensure that the output power is lower than the vehicle idle power constraint requirements. By the method of injecting water to suspend the operation of the fuel cell stack, the generation of the hydrogen-air interface is avoided, the attenuation damage of the fuel cell stack caused by the method of suspending the operation is reduced, the hydrogen consumption is reduced, and the service life of the fuel cell stack is increased.

[0017] To achieve the above object, an embodiment of the second aspect of the present invention provides a control device for a fuel cell system, including: a determination module configured to determine whether the fuel cell system is in an idle condition; a first response module configured to, in response to the fuel cell system being in the idle condition, determine whether both the first fuel cell stack and the second fuel cell stack are in a working state; a second response module configured to, in response to both the first fuel cell stack and the second fuel cell stack being in the working state, control a first shut-off valve, a second shut-off valve, a water pump, a first switch, a second switch, a third switch, a first electromagnetic directional valve, a second electromagnetic directional valve, a third electromagnetic directional valve, and a fourth electromagnetic directional valve according to the remaining service lives of the first fuel cell stack and the second fuel cell stack, so that either the first fuel cell stack or the second fuel cell stack is in a non-working state.

[0018] The control device for a fuel cell system according to an embodiment of the present invention includes: a determination module configured to determine whether the fuel cell system is in an idle condition; a first response module configured to, in response to the fuel cell system being in the idle condition, determine whether both the first fuel cell stack and the second fuel cell stack are in a working state; a second response module configured to, in response to both the first fuel cell stack and the second fuel cell stack being in the working state, control a first shut-off valve, a second shut-off valve, a water pump, a first switch, a second switch, a third switch, a first electromagnetic directional valve, a second electromagnetic directional valve, a third electromagnetic directional valve, and a fourth electromagnetic directional valve according to the remaining service lives of the first fuel cell stack and the second fuel cell stack, so that either the first fuel cell stack or the second fuel cell stack is in a non-working state. Thus, this device reduces the idle power of the fuel cell system to meet the vehicle idle power constraint requirements and voltage requirements. In the idle condition, the operation changes from multiple fuel cell stacks working to a single fuel cell stack working. On this basis, the current density can be increased to reduce the average single-cell voltage to be lower than 0.85V. The single fuel cell stack working can also ensure that the output power is lower than the vehicle idle power constraint requirements. By the method of injecting water to shut down the stack, the generation of the hydrogen-air interface is avoided, the attenuation damage to the stack caused by the stack shutdown method is reduced, the hydrogen consumption is reduced, and the service life of the fuel cell stack is increased.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A block diagram of a fuel cell system according to some embodiments of the present invention;

[0021] Figure 2 A block diagram of a switch circuit according to some embodiments of the present invention;

[0022] Figure 3 A flowchart of a control method for a fuel cell system according to some embodiments of the present invention;

[0023] Figure 4 A flowchart of a control method for a fuel cell system according to other embodiments of the present invention;

[0024] Figure 5 A schematic block diagram of a control device for a fuel cell system according to some embodiments of the present invention.

[0025] Description of reference numerals:

[0026] 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 electromagnetic change-over valve, 10 - drain valve, 11 - hydrogen circulation pump, 12 - second electromagnetic change-over valve, 2 - proportional valve, 28 - first air compressor, 15 - second air compressor, 14 - intercooler, 18 - bypass valve, 19 - third shut-off valve, 20 - third electromagnetic change-over valve, 29 - fourth electromagnetic change-over valve, 17 - humidifier, 25 - water separator, 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 flowmeter, 31 - second flowmeter, 32 - third flowmeter, and 33 - fourth flowmeter. Detailed embodiments

[0027] In order to make the objectives, technical solutions, and advantages of the present invention more clear and understandable, the present invention will be further described in detail below with reference to specific embodiments and the accompanying drawings.

[0028] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present invention should have the ordinary meanings understood by those of ordinary skill in the field to which the present invention pertains. The "first", "second" and similar terms used in the embodiments of the present invention do not denote any order, quantity or importance, but are only used to distinguish different components. Words such as "including" or "comprising" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "left", "right", etc. are only used to represent relative position relationships, and when the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0029] As described in the background art section, currently, the idle power of high-power fuel cell systems is relatively high, which easily causes the problem of overcharging of the power battery. At the same time, the lower the idle power of high-power fuel cell systems, the lower the current density and the higher the average single-cell voltage, resulting in an increased degree of stack attenuation. Therefore, manufacturers stipulate that the power of the fuel cell system under idle conditions cannot be higher than a certain value, and the average single-cell voltage cannot exceed a certain value.

[0030] Under idle conditions, high-power fuel cell systems are characterized by high idle power, making it difficult to meet the upper limit requirement of the vehicle's idle power. At the same time, they are also characterized by high average single-cell voltage, which accelerates the attenuation of the stack and shortens the service life of the fuel cell.

[0031] During the implementation of the present invention, the applicant found that for fuel cell systems under idle conditions, they generally exhibit a high potential. For high-power fuel cell systems, their average single-cell voltage is relatively high, which easily accelerates the attenuation of the stack. In the related art, by adopting a high-potential method in a short period of time, this method will exacerbate the attenuation of the stack and seriously affect the service life of the fuel cell.

[0032] Therefore, the present invention reduces the idle power of the fuel cell system to meet the vehicle's idle power constraint requirements and voltage requirements. Under idle conditions, the operation mode changes from multiple stacks working to a single stack working. On this basis, the current density can be increased to reduce the average single-cell voltage to be lower than 0.85V. The single-stack operation can also ensure that the output power is lower than the idle power constraint requirements of the vehicle. By means of injecting water to shut down the stack, the generation of the hydrogen-air interface is avoided, the attenuation damage of the shutdown method to the stack is reduced, the hydrogen consumption is decreased, and the service life of the stack is prolonged.

[0033] Next, the control method of the fuel cell system and the control device of the fuel cell system proposed in the embodiments of the present invention will be described with reference to the accompanying drawings.

[0034] Reference Figure 1 FIG. 1 is a block diagram of a fuel cell system according to some embodiments of the present invention.

[0035] The fuel cell system 100 of the present invention includes a first fuel cell stack 8, a second fuel cell stack 7, a hydrogen supply circuit, and an air supply circuit. Among them, the number of fuel cell stacks is at least two, and the connection mode of the fuel cell stacks can be a parallel connection mode.

[0036] 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 intake port of the first ejector 6 through the first shut-off valve 4. Among them, the hydrogen source 1 is used to supply hydrogen, and the outlet of the first ejector 6 is connected to the first inlet of the first fuel cell stack 8.

[0037] 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 intake port of the second ejector 5 through the second shut-off valve 3. The outlet of the second ejector 5 is connected to the first inlet of the second fuel cell stack 7.

[0038] The hydrogen supply circuit further includes a hydrogen circulation circuit. The hydrogen circulation circuit 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 intake port of the first ejector 6, and the second outlet of the second electromagnetic reversing valve 12 is connected to the second intake port of the second ejector 5. Among them, the second electromagnetic reversing valve 12 is used as a preliminary working link for stack shutdown to prepare for stack shutdown work.

[0039] The hydrogen supply circuit further includes a proportional valve 2. The inlet of the proportional valve 2 is connected to the hydrogen source 1, and the outlet of the proportional valve 2 is respectively connected to the intake ports of the first shut-off valve 4 and the second shut-off valve 3.

[0040] 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 electromagnetic reversing valve 20, and a fourth electromagnetic reversing valve 29. The air inlet of the first air compressor 28 is connected to the atmosphere, 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 electromagnetic reversing valve 29, the outlet of the fourth electromagnetic reversing valve 29 is connected to the first inlet of the third electromagnetic reversing valve 20, and the first outlet of the third electromagnetic reversing valve 20 is connected to the second inlet of the second fuel cell stack 7.

[0041] 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 reversing valve 20 through the third shut-off valve 19, and the second outlet of the third solenoid reversing valve 20 is connected to the second inlet of the first fuel cell stack 8.

[0042] The air supply circuit also includes an air circulation circuit, which includes a humidifier 17, a water separator 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 air 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 separator 25 through the sixth shut-off valve 24, the first outlet of the humidifier 17 is connected to the second inlet of the third electromagnetic reversing valve 20 through 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 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 separator 25 through the back pressure valve 23, the first outlet of the water separator 25 is connected to the water tank 26, and the second outlet of the water separator 25 is connected to the atmospheric environment.

[0043] The fuel cell system 100 further includes a water pump 27 , a water inlet of the water pump 27 is connected to the water tank 26 , and a water outlet of the water pump 27 is connected to the second inlet of the fourth electromagnetic reversing valve 29 , wherein the water pump 27 is used to extract the stored water in the water tank 26 .

[0044] The purge function can be realized by starting the first air compressor 28, closing the water pump 27, and changing the opening of the fourth electromagnetic reversing valve 29, thereby finally releasing the resting function of the fuel cell stack.

[0045] The fuel cell system 100 further includes a switching circuit disposed between the first fuel cell stack 8 and the second fuel cell stack 7 for controlling the operating states of the first fuel cell stack 8 and the second fuel cell stack 7 (i.e., controlling whether the operating states of the first fuel cell stack 8 and the second fuel cell stack 7 are in the shutdown state).

[0046] Reference Figure 2 , which is a block schematic diagram of the switching circuit according to some embodiments of the present invention. The switching circuit includes a DC converter 35, a first switch 36, a second switch 38, and a third switch 37. The positive pole of the DC converter 35 is selectively connected to the positive pole of the first fuel cell stack 8 or the positive pole of the second fuel cell stack 7 through the first switch 36. The negative pole of the first fuel cell stack 8 is selectively connected to the positive pole of the first fuel cell stack 8 through the second switch 38. The negative pole of the DC converter 35 is selectively connected to the negative pole of the first fuel cell stack 8 or the negative pole of the second fuel cell stack 7 through the third switch 37.

[0047] 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., there is no shutdown phenomenon), the first switch 36 is connected to the positive pole of the first fuel cell stack 8, the second switch 38 is connected to the negative pole of the second fuel cell stack 7, and the third switch 37 is in the closed state. When a single fuel cell stack is required to operate, the third switch 37 is in the open state, the first switch 36 is connected to the positive pole of the operating fuel cell stack, and the second switch 38 is connected to the negative pole of the operating fuel cell stack.

[0048] The fuel cell system 100 further includes a water cooling circuit 34 that penetrates 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 the first fuel cell stack 8 and the second fuel cell stack 7, so as to cool the first fuel cell stack 8 or the second fuel cell stack 7 or both the first fuel cell stack 8 and the second fuel cell stack 7 when the first fuel cell stack 8 or the second fuel cell stack 7 or both the first fuel cell stack 8 and the second fuel cell stack 7 are at a high temperature.

[0049] After the shutdown function of the fuel cell stack is realized, the water cooling circuit 34 still pumps coolant into the first fuel cell stack 8 or the second fuel cell stack 7 or both the first fuel cell stack 8 and the second fuel cell stack 7, and adjusts the flow ratio of the coolant entering the cycle through a thermostat. The coolant output by the operating fuel cell stack can provide heat to the shutdown fuel cell stack through the water cooling circuit 34, so as to effectively avoid the situation of icing of the shutdown fuel cell stack.

[0050] The fuel cell system 100 further includes a first flowmeter 30, a second flowmeter 31, a third flowmeter 32, and a fourth flowmeter 3333. The first flowmeter 30 is disposed between the first outlet of the third electromagnetic directional valve 20 and the second inlet of the second fuel cell stack 7 for detecting a first flow rate at the second inlet of the second fuel cell stack 7. The second flowmeter 31 is disposed between the second outlet of the third electromagnetic directional valve 20 and the second inlet of the first fuel cell stack 8 for detecting a second flow rate at the second inlet of the first fuel cell stack 8. The third flowmeter 32 is disposed between the second outlet of the second fuel cell stack 7 and the second inlet of the humidifier 17 for detecting a third flow rate at the second outlet of the second fuel cell stack 7. The fourth flowmeter 3333 is disposed between the second outlet of the first fuel cell stack 8 and the second inlet of the humidifier 17 for detecting a fourth flow rate at the second outlet of the first fuel cell stack 8.

[0051] Thus, the fuel cell system 100 of the present invention 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 electromagnetic directional valve 9, a drain valve 10, a hydrogen circulation pump 11, a second electromagnetic 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 electromagnetic directional valve 20, a fourth electromagnetic directional valve 29, a humidifier 17, a water separator 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 converter 35, a first switch 36, a second switch 38, a third switch 37, a water cooling circuit 34, a first flowmeter 30, a second flowmeter 31, a third flowmeter 32, and a fourth flowmeter 3333.

[0052] Hydrogen passes through the hydrogen source 1 and via the proportional valve 2, and enters the second shut-off valve 3 and the first shut-off valve 4 respectively, and passes through the second ejector 5 and the first ejector 6 to enter the first fuel cell stack 8 and the second fuel cell stack 7 respectively. The remaining mixed gas enters the drain valve 10 through the first electromagnetic directional valve 9, the liquid water enters the water tank 26, and the gas re-enters the first ejector 6 and the second ejector 5 through the hydrogen circulation pump 11 and the second electromagnetic directional valve 12 for secondary flow.

[0053] Air passes through the atmospheric environment, through the first air compressor 28 and the second air compressor 15, and enters the intercooler 14 respectively, and then enters the three-way valve 16 and the bypass valve 18. The air that converges into the three-way valve 16 can enter the water separator 25 through the sixth shut-off valve 24, or can converge with the bypass valve 18 interface through the humidifier 17, and then enter the first fuel cell stack 8 and the second fuel cell stack 7 through the third shut-off valve 19 and the third electromagnetic reversing valve 20. The remaining gas can enter the fourth shut-off valve 21 and the fifth shut-off valve 22 respectively, then merge and enter the humidifier 17, and enter the water separator 25 through the back pressure valve 23. The liquid water enters the water tank 26, and the gas part is discharged into the atmospheric environment. The water in the water tank 26 can be pumped into a certain fuel cell stack through the water pump 27 and the fourth electromagnetic reversing valve 29 according to the working conditions.

[0054] Reference Figure 3 , is a flowchart of a control method for a fuel cell system according to some embodiments of the present invention.

[0055] As Figure 3 shown, the control method of the fuel cell system according to the embodiments of the present invention may include the following steps:

[0056] S301, determine whether the fuel cell system is in an idle condition.

[0057] Specifically, it can be determined whether the fuel cell system is in an idle condition by power output, current and voltage, air system, temperature and pressure, or drainage and exhaust. For example, the output power of the fuel cell stack can be monitored by a sensor. When the monitored output power is low (usually in the range of 4.5 - 12 kW), it can indicate that the fuel cell system is in an idle condition; when the monitored output power is high, it can indicate that the fuel cell system is in a non-idle condition. Another example is that the drainage and exhaust of the fuel cell system can be monitored by a sensor. When the monitored frequency of drainage and exhaust is low, it can indicate that the fuel cell system is in an idle condition; when the monitored frequency of drainage and exhaust is high, it can indicate that the fuel cell system is in a non-idle condition.

[0058] S302, in response to the fuel cell system being in an idle condition, determine whether both the first fuel cell stack and the second fuel cell stack are in a working state.

[0059] Specifically, when the fuel cell system is in an idle condition, it can indicate that the output power of the fuel cell stack is low; the working current of the fuel cell stack is low, and the voltage gradually decreases; the air bypass valve is open, the speed of the air compressor is fixed, and the air inlet pressure is stable; the temperature and air inlet pressure of the fuel cell stack are stable within a certain range; the frequency of drainage and exhaust is low. Then, it is determined again whether both the first fuel cell stack and the second fuel cell stack are in a working state.

[0060] S303, in response to both the first fuel cell stack and the second fuel cell stack being in the operating state, control the first shut-off valve, the second shut-off valve, the water pump, the first switch, the second switch, the third switch, the first electromagnetic directional valve, the second electromagnetic directional valve, the third electromagnetic directional valve, and the fourth electromagnetic directional valve according to the remaining service lives of the first fuel cell stack and the second fuel cell stack, so that either the first fuel cell stack or the second fuel cell stack is in the non-operating state.

[0061] Specifically, when both the first fuel cell stack and the second fuel cell stack are in the operating state, that is, no fuel cell stack is in the shutdown state, control the first shut-off valve, the second shut-off valve, the water pump, the first switch, the second switch, the third switch, the first electromagnetic directional valve, the second electromagnetic directional valve, the third electromagnetic directional valve, and the fourth electromagnetic directional valve according to the remaining service lives of the first fuel cell stack and the second fuel cell stack. For example, when the remaining service life of the first fuel cell stack is relatively high, control the positive pole of the DC converter to be connected to the positive pole of the first fuel cell stack through the first switch, and the negative pole of the DC converter to be connected to the negative pole of the first fuel cell stack through the third switch, control the second switch to be off, control the first electromagnetic directional valve and the second electromagnetic directional valve to be in the first set position, the third electromagnetic directional valve to be in the third set position, and control the second shut-off valve to be closed, so that the second fuel cell stack is in the non-operating state. Another example is that when the remaining service life of the second fuel cell stack is relatively high, control the positive pole of the DC converter to be connected to the positive pole of the second fuel cell stack through the first switch, and the negative pole of the DC converter to be connected to the negative pole of the second fuel cell stack through the third switch, control the second switch to be off, control the first electromagnetic directional valve and the second electromagnetic directional valve to be in the third set position, the third electromagnetic directional valve to be in the first set position, and control the first shut-off valve to be closed, so that the first fuel cell stack is in the non-operating state. Thus, the switching function between multi-stack operation and single-stack operation is realized, the phenomena of high potential and high power caused by high-power fuel cells in the idle condition are solved, the stack attenuation is reduced, the idle power requirement of the whole vehicle is met, and the hydrogen consumption is reduced.

[0062] In some embodiments, when the first fuel cell stack and the second fuel cell stack are operating, when a shutdown instruction is received, the first air compressor and the second air compressor are turned on to purge the first fuel cell stack and the second fuel cell stack, and then the second shut-off valve, the first shut-off valve, the third shut-off valve, the fourth shut-off valve, and the fifth shut-off valve are closed. During single-stack operation, regardless of whether the shutdown process is completed, the purging work is directly carried out to drain the water in the stack, preventing the fuel cell system from freezing after stopping.

[0063] In some embodiments of the present invention, before determining whether the fuel cell system is in an idle condition, the method further includes: controlling the opening of a first shut-off valve, a second shut-off valve, a third shut-off valve, a fourth shut-off valve, and a fifth shut-off valve, controlling a first electromagnetic reversing valve, a second electromagnetic reversing valve, a third electromagnetic reversing valve, and a fourth electromagnetic reversing valve to be in a second preset position, and controlling the water pump to be closed.

[0064] Wherein, the position of the electromagnetic reversing valve close to the spring is the first preset position, the position of the electromagnetic reversing valve away from the spring is the third preset position, and the position between the first preset position and the third preset position of the electromagnetic reversing valve is the second preset position.

[0065] Specifically, before determining whether the fuel cell system is in an idle condition, control the opening of the first shut-off valve, the second shut-off valve, the third shut-off valve, the fourth shut-off valve, and the fifth shut-off valve, and control the first electromagnetic reversing valve, the second electromagnetic reversing valve, the third electromagnetic reversing valve, and the fourth electromagnetic reversing valve to be in the second preset position. When the first electromagnetic reversing valve, the second electromagnetic reversing valve, the third electromagnetic reversing valve, and the fourth electromagnetic reversing valve are in the second preset position, there is no gas flow. Control a first flowmeter, a second flowmeter, a third flowmeter, and a fourth flowmeter to record the flow rates at the inlets and outlets of the first fuel cell stack and the second fuel cell stack, so that hydrogen and air can be supplied to the first fuel cell stack and the second fuel cell stack and the mixture at the outlets of the first fuel cell stack and the second fuel cell stack can flow back to the atmospheric environment and the water tank. Among them, the second air compressor keeps working all the time to enable the fuel cell to work normally, so that the first fuel cell stack and the second fuel cell stack can work normally, and control the water pump to be closed to prevent the stored water in the water tank from being pumped into the first fuel cell stack and the second fuel cell stack.

[0066] In some embodiments of the present invention, the first shut-off valve, the second shut-off valve, the water pump, the first switch, the second switch, the third switch, the first electromagnetic reversing valve, the second electromagnetic reversing valve, the third electromagnetic reversing valve, and the fourth electromagnetic reversing valve are controlled according to the remaining service life of the first fuel cell stack and the second fuel cell stack, so that the first fuel cell stack or the second fuel cell stack is in a non-operating state, including: controlling the fourth electromagnetic reversing valve to be in the third preset position, controlling the water pump to be turned on, and controlling the third switch to be turned off; calculating the first remaining service life of the first fuel cell stack and the second remaining service life of the second fuel cell stack, and comparing the magnitudes of the first remaining service life and the second remaining service life; in response to the first remaining service life being lower than the second remaining service life, controlling the positive pole of the DC converter to be connected to the positive pole of the second fuel cell stack through the first switch, and the negative pole of the DC converter to be connected to the negative pole of the second fuel cell stack through the third switch, controlling the first electromagnetic reversing valve and the second electromagnetic reversing valve to be in the third preset position, the third electromagnetic reversing valve to be in the first preset position, and controlling the first shut-off valve to be closed.

[0067] Specifically, when the fuel cell system is in the idle condition and both the first fuel cell stack and the second fuel cell stack are in the working state, to reduce the attenuation of the first fuel cell stack and the second fuel cell stack, the fourth electromagnetic directional valve is controlled to be in the third preset position, the water pump is controlled to be turned on, and the third switch is controlled to be turned off. Among them, when the fourth electromagnetic directional valve is in the third preset position, the water of the water pump can flow into the third electromagnetic directional valve, and whether the water of the water pump enters the fuel cell stack or which part of the fuel cell stack it enters is determined according to the position of the third electromagnetic directional valve, so as to realize that the water of the water pump is pumped into the first fuel cell stack and the second fuel cell stack to discharge the air in the first fuel cell stack and the second fuel cell stack. The controller calculates the first remaining life of the first fuel cell stack and the second remaining life of the second fuel cell stack, compares the magnitudes of the first remaining life and the second remaining life, and judges whether the first remaining life is lower than the second remaining life. When the first remaining life is lower than the second remaining life, it can indicate that the first fuel cell stack can be shut down for maintenance, and the second fuel cell stack works normally. At this time, the positive pole of the DC converter is connected to the positive pole of the second fuel cell stack through the first switch, the negative pole of the DC converter is connected to the negative pole of the second fuel cell stack through the third switch, the second switch is controlled to be turned off, and the DC converter will output power by the second fuel cell stack. The first electromagnetic directional valve and the second electromagnetic directional valve are controlled to be in the third preset position, and the first shut-off valve is controlled to be closed to realize the hydrogen supply cut-off of the first fuel cell stack on the hydrogen path. The third electromagnetic directional valve is controlled to be in the first preset position. Among them, when the third electromagnetic directional valve is in the first preset position, the gas of the third shut-off valve enters the second fuel cell stack, and the second fuel cell stack works normally. The water in the fourth electromagnetic directional valve enters the first fuel cell stack through the third electromagnetic directional valve to realize shutdown for maintenance, so as to realize the air supply cut-off of the first fuel cell stack on the air path. At this time, the first fuel cell stack can neither output power nor receive gas supply, which will cause a high potential of the first fuel cell stack and cause attenuation inside the first fuel cell stack. To reduce the attenuation of the first fuel cell stack, the method of turning on the water pump to pump water into the first fuel cell stack is adopted to discharge the air, and the second flowmeter and the fourth flowmeter respectively and real-time detect the flow rates at the inlet and outlet of the first fuel cell stack.

[0068] In some embodiments of the present invention, the above method further includes: in response to the second remaining life being lower than the first remaining life, controlling the positive pole of the DC converter to be connected to the positive pole of the first fuel cell stack through the first switch, the negative pole of the DC converter to be connected to the negative pole of the first fuel cell stack through the third switch, controlling the first electromagnetic directional valve and the second electromagnetic directional valve to be in the first preset position, the third electromagnetic directional valve to be in the third preset position, and controlling the second shut-off valve to be closed.

[0069] Specifically, when the second remaining life of the second fuel cell stack is lower than the first remaining life of the first fuel cell stack, it can be indicated that the second fuel cell stack can be shut down for maintenance, and the first fuel cell stack operates normally. At this time, control the positive pole of the DC converter to be connected to the positive pole of the first fuel cell stack through the first switch, and the negative pole of the DC converter to be connected to the negative pole of the first fuel cell stack through the third switch. Control the second switch to be turned off. The DC converter will output power from the first fuel cell stack. Control the first electromagnetic directional valve and the second electromagnetic directional valve to be in the first preset position, and control the second shut-off valve to be closed to cut off the hydrogen supply on the hydrogen path of the second fuel cell stack. Control the third electromagnetic directional valve to be in the third preset position to cut off the air supply on the air path of the second fuel cell stack. At this time, the second fuel cell stack can neither output power nor receive gas supply, which will cause a high potential in the second fuel cell stack and cause attenuation inside the second fuel cell stack. To reduce the attenuation of the second fuel cell stack, a water pump will be turned on to pump water into the second fuel cell stack to expel air, and the first flowmeter and the third flowmeter will detect the flow rates at the inlet and outlet of the second fuel cell stack in real time.

[0070] In some embodiments of the present invention, the above method further includes: determining whether the difference between the second flow rate detected by the second flowmeter and the fourth flow rate detected by the fourth flowmeter is less than a preset difference; in response to the difference between the second flow rate and the fourth flow rate being less than the preset difference, controlling the fifth shut-off valve to be closed, controlling the water pump to stop working, and controlling the fourth electromagnetic directional valve to be in the second preset position. Among them, the preset difference can be set according to the actual situation. For example, the preset difference can be 5%.

[0071] Specifically, after obtaining the second flow rate detected by the second flowmeter and the fourth flow rate detected by the fourth flowmeter, calculate the difference between the second flow rate detected by the second flowmeter and the fourth flow rate detected by the fourth flowmeter, and determine whether the difference between the second flow rate detected by the second flowmeter and the fourth flow rate detected by the fourth flowmeter is less than the preset difference. When the difference between the second flow rate and the fourth flow rate is less than the preset difference, it can be indicated that the difference between the second flow rate and the fourth flow rate is very small, that is, in order to complete the shutdown for maintenance of the fuel cell stack to be shut down for maintenance, the water inflow and drainage of the fuel cell stack to be shut down for maintenance should be approximately equal, and the air in the first fuel cell stack has been completely discharged. At this time, control the fifth shut-off valve to be closed, control the water pump to stop working, and control the fourth electromagnetic directional valve to be in the second preset position, and the shutdown for maintenance operation of the first fuel cell stack ends.

[0072] In some embodiments of the present invention, the above method also includes: determining whether the difference between the first flow detected by the first flow meter and the third flow detected by the third flow meter is less than a preset difference; in response to the difference between the first flow and the third flow being less than the preset difference, controlling the fourth shut-off valve to close, controlling the water pump to stop working, and controlling the fourth solenoid reversing valve to be located at a second preset position.

[0073] Specifically, after obtaining the first flow detected by the first flow meter and the third flow detected by the third flow meter, the difference between the first flow detected by the first flow meter and the third flow detected by the third flow meter is calculated to determine whether the difference between the first flow detected by the first flow meter and the third flow detected by the third flow meter is less than a preset difference. When the difference between the first flow and the third flow is less than the preset difference, it can be said that the difference between the first flow and the third flow is very small, that is, in order to complete the shutdown of the stack, the water intake and water discharge of the stack should be approximately equal, and the air of the second fuel cell stack has been completely discharged. At this time, the fourth shut-off valve is controlled to close, the water pump is controlled to stop working, and the fourth electromagnetic reversing valve is controlled to be in the second preset position, and the shutdown of the second fuel cell stack is completed.

[0074] In some embodiments of the present invention, the above method also includes: in response to the fuel cell system being in a non-idle condition, determining whether the first fuel cell stack and the second fuel cell stack are both in a working state; in response to the first fuel cell stack or the second fuel cell stack being in a non-working state, controlling the first air compressor to operate; controlling the first shut-off valve, the second shut-off valve, the fourth shut-off valve, the fifth shut-off valve, the first switch, the second switch and the third switch according to the working power of the first fuel cell stack and the second fuel cell stack, and controlling the first solenoid reversing valve, the second solenoid reversing valve and the fourth solenoid reversing valve to ensure that the first fuel cell stack and the second fuel cell stack are both in a working state.

[0075] Specifically, when the fuel cell system is in a non-idle condition, it is determined whether the first fuel cell stack and the second fuel cell stack are both in working condition. When the first fuel cell stack or the second fuel cell stack is in a non-working condition, that is, the first fuel cell stack is off or the second fuel cell stack is off, the first air compressor is controlled to operate to purge the first fuel cell stack to stop the first fuel cell stack from being off. The first shut-off valve, the second shut-off valve, the fourth shut-off valve, the fifth shut-off valve, the first switch, the second switch and the third switch are controlled according to the working power of the first fuel cell stack and the second fuel cell stack. The first solenoid reversing valve, the second solenoid reversing valve and the fourth solenoid reversing valve are controlled to make the first fuel cell stack and the second fuel cell stack both in working condition, thereby achieving precise management of the working condition of each fuel cell stack.

[0076] In some embodiments of the present invention, the first shut-off valve, the second shut-off valve, the fourth shut-off valve, the fifth shut-off valve, the first switch, the second switch, and the third switch are controlled according to the operating power of the first fuel cell stack and the second fuel cell stack, and the first electromagnetic reversing valve, the second electromagnetic reversing valve, and the fourth electromagnetic reversing valve are controlled to enable both the first fuel cell stack and the second fuel cell stack to be in an operating state, including: determining the fuel cell stack in a non-operating state according to the operating power of the first fuel cell stack and the second fuel cell stack; in response to the first fuel cell stack being in a non-operating state, controlling the first shut-off valve and the fifth shut-off valve to open, and controlling the first electromagnetic reversing valve and the second electromagnetic reversing valve to be in the second preset position and the fourth electromagnetic reversing valve to be in the first preset position; obtaining the single-cell voltage data and the water content of the first fuel cell stack, and determining whether the first fuel cell stack is in a flooded state according to the water content of the first fuel cell stack; in response to the first fuel cell stack not being in a flooded state, controlling the positive pole of the DC converter to be connected to the positive pole of the first fuel cell stack through the first switch, the negative pole of the DC converter to be connected to the negative pole of the second fuel cell stack through the third switch, and the second switch to be closed; determining whether the single-cell voltage data of the first fuel cell stack is normal; in response to the single-cell voltage data of the first fuel cell stack being normal, controlling the third electromagnetic steering valve to be in the second preset position and the fourth electromagnetic steering valve to be in the second preset position, and controlling the first air compressor to stop working.

[0077] Specifically, after obtaining the operating powers of the first fuel cell stack and the second fuel cell stack, it is determined which fuel cell stack is not operating based on the operating powers of the first fuel cell stack and the second fuel cell stack. When the first fuel cell stack is in a non-operating state, that is, the first fuel cell stack is not operating and the second fuel cell stack is in an operating state, the first shut-off valve and the fifth shut-off valve are controlled to open, the first electromagnetic directional valve and the second electromagnetic directional valve are controlled to be in the second preset position to achieve the circulation of hydrogen and the discharge of water, the first air compressor starts, and the fourth electromagnetic directional valve is in the first preset position to achieve the entry of air and realize the purging function to discharge the excess water in the fuel cell stack, so that the idle fuel cell stack can operate with high performance. The single-cell voltage data and the water content of the first fuel cell stack can be detected by the voltage sensor and the water content sensor arranged on the first fuel cell stack. After obtaining the water content of the first fuel cell stack, it is judged whether the first fuel cell stack is in a flooded state according to the water content of the first fuel cell stack. When the first fuel cell stack is not in a flooded state, it can indicate that the water content of the first fuel cell stack is in a normal state or a dry membrane state. Among them, the dry membrane state is a state harmful to the fuel cell. When the water content of the first fuel cell stack is in the dry membrane state, it can be compensated through links such as a humidifier or self-humidification. The positive pole of the DC converter is connected to the positive pole of the first fuel cell stack through the first switch, the negative pole of the DC converter is connected to the negative pole of the second fuel cell stack through the third switch, and the second switch is closed. When the first fuel cell stack is in a flooded state, it can indicate that there is more water in the first fuel cell stack, and the first air compressor is controlled to continue working to continue purging the first fuel cell stack. After obtaining the single-cell voltage data of the first fuel cell stack, it is judged whether the single-cell voltage data of the first fuel cell stack is normal. When the single-cell voltage data of the first fuel cell stack is normal, the third electromagnetic directional valve is controlled to be in the second preset position, the fourth electromagnetic directional valve is controlled to be in the second preset position, and the first air compressor is controlled to stop working. At this time, the shutdown of the first fuel cell stack ends. When the single-cell voltage data of the first fuel cell stack is abnormal, the single-cell voltage data of the first fuel cell stack is continuously detected.

[0078] In some embodiments of the present invention, the above method further includes: in response to the second fuel cell stack being in a non-operating state, controlling the second shut-off valve and the fourth shut-off valve to open, and controlling the first electromagnetic reversing valve and the second electromagnetic reversing valve to be in the second preset position and the fourth electromagnetic reversing valve to be in the first preset position; obtaining the single-cell voltage data and the water content of the second fuel cell stack, and determining whether the second fuel cell stack is in a flooded state according to the water content of the second fuel cell stack; in response to the second fuel cell stack not being in a flooded state, controlling the positive pole of the DC converter to be connected to the positive pole of the first fuel cell stack through the first switch, the negative pole of the DC converter to be connected to the negative pole of the second fuel cell stack through the third switch, and the second switch to be closed; determining whether the single-cell voltage data of the second fuel cell stack is normal; in response to the single-cell voltage data of the second fuel cell stack being normal, controlling the third electromagnetic steering valve to be in the second preset position and the fourth electromagnetic steering valve to be in the second preset position, and controlling the first air compressor to stop working.

[0079] Specifically, when the second fuel cell stack is in a non-operating state, i.e., the second fuel cell stack is not operating and the first fuel cell stack is in an operating state, control the second shut-off valve and the fourth shut-off valve to open, control the first electromagnetic reversing valve and the second electromagnetic reversing valve to be in the second preset position, realize the circulation of hydrogen and the discharge of water, start the first air compressor, and the fourth electromagnetic reversing valve is in the first preset position to realize the entry of air, realize the purging function, and discharge the excess water in the fuel cell stack, so that the idle fuel cell stack can work with high performance. The single-cell voltage data and water content of the second fuel cell stack can be detected by the voltage sensor and water content sensor set on the second fuel cell stack. After obtaining the water content of the second fuel cell stack, judge whether the second fuel cell stack is in a flooded state according to the water content of the second fuel cell stack. When the second fuel cell stack is not in a flooded state, it can indicate that the water content of the second fuel cell stack is in a normal state or a dry membrane state. When the water content of the second fuel cell stack is in a dry membrane state, it can be compensated through a humidifier or self-humidification and other links. Control the positive pole of the DC converter to be connected to the positive pole of the first fuel cell stack through the first switch, the negative pole of the DC converter to be connected to the negative pole of the second fuel cell stack through the third switch, and the second switch to be closed. When the second fuel cell stack is in a flooded state, it can indicate that there is more water in the second fuel cell stack. Control the first air compressor to continue working to continue purging the second fuel cell stack. After obtaining the single-cell voltage data of the second fuel cell stack, judge whether the single-cell voltage data of the second fuel cell stack is normal. When the single-cell voltage data of the second fuel cell stack is normal, control the third electromagnetic steering valve to be in the second preset position and the fourth electromagnetic steering valve to be in the second preset position, and control the first air compressor to stop working. At this time, the shutdown of the second fuel cell stack ends. When the single-cell voltage data of the second fuel cell stack is abnormal, continue to detect the single-cell voltage data of the second fuel cell stack.

[0080] Thus, in the process of analyzing the influence of working conditions on the stack attenuation, it is found that the start-stop working condition has the greatest attenuation on the stack, which means that users need to minimize the number of starts and stops of the fuel cell. The attenuation mechanism for the start-stop working condition is mainly because there is a hydrogen-air interface and high voltage at the anode end, resulting in reverse current and carbon corrosion at the cathode, so the start-stop working condition has a great impact on the fuel cell attenuation.

[0081] In consideration of this attenuation mechanism and its influence, the present invention, in the start-stop working condition, pumps water into the stack to be idled to discharge air, and then shuts down the stack, realizing the conversion from dual-stack operation to single-stack operation. This approach avoids the generation of hydrogen-air interfaces, reduces the attenuation damage of the shutdown method to the stack, and improves the service life of the stack.

[0082] As a specific embodiment, such as Figure 4As shown in the figure, the flowchart of the control method of the fuel cell system of the present invention may include the following steps:

[0083] S401, the shut-off valves (3, 4, 19, 21, 22) are opened.

[0084] In this step, the first shut-off valve, the second shut-off valve, the third shut-off valve, the fourth shut-off valve, and the fifth shut-off valve are controlled to be opened.

[0085] S402, the electromagnetic reversing valves (9, 12, 20, 29) are in the 2 position.

[0086] In this step, the first electromagnetic reversing valve, the second electromagnetic reversing valve, the third electromagnetic reversing valve, and the fourth electromagnetic reversing valve are controlled to be in the second preset position.

[0087] S403, the flowmeters 1-4 (30-33) record the flow rate.

[0088] In this step, the first flowmeter, the second flowmeter, the third flowmeter, and the fourth flowmeter record the flow rates at the inlets and outlets of the first fuel cell stack and the second fuel cell stack.

[0089] S404, the stack is purged and operates normally.

[0090] S405, determine whether the fuel cell system is in the idle condition. If so, execute step S406; if not, execute step S433.

[0091] S406, the FCCU switches to the single-stack supply strategy.

[0092] S407, determine whether there is a stack shutdown. If so, return to step S405; if not, execute step S408.

[0093] In this step, it is determined whether there is a stack shutdown in the first fuel cell stack and the second fuel cell stack.

[0094] S408, calculate the remaining life of the dual stacks.

[0095] In this step, calculate the remaining life of the first fuel cell stack and the second fuel cell stack.

[0096] S409, the water pump (27) operates.

[0097] S410, switch 3 (38) is disconnected.

[0098] In this step, the second switch is disconnected.

[0099] S411, the electromagnetic reversing valve 4 (29) is in the 3 position.

[0100] In this step, the fourth electromagnetic directional valve is in the third preset position.

[0101] S412. Determine whether the remaining life of stack 1 is lower than that of stack 2. If so, execute step S413; if not, execute step S424.

[0102] In this step, determine whether the remaining life of the first fuel cell stack is lower than that of the second fuel cell stack.

[0103] S413. Switch 1 (36) connects to the positive electrode of stack 2 (7).

[0104] In this step, the positive electrode of the DC converter is connected to the positive electrode of the second fuel cell stack through the first switch.

[0105] S414. Switch 2 (37) connects to the negative electrode of stack 2 (7).

[0106] In this step, the negative electrode of the DC converter is connected to the negative electrode of the second fuel cell stack through the third switch.

[0107] S415. Electromagnetic directional valves 1 and 2 (9, 12) are in the 3 position.

[0108] In this step, the first electromagnetic directional valve and the second electromagnetic directional valve are in the third preset position.

[0109] S416. Shut-off valve 1 (4) closes.

[0110] In this step, control the first shut-off valve to close.

[0111] S417. Electromagnetic directional valve 3 (20) is in the 1 position.

[0112] In this step, the third electromagnetic directional valve is in the first preset position.

[0113] S418. Flowmeters 2 and 4 (31, 33) record the flow rate.

[0114] In this step, the second flowmeter and the fourth flowmeter record the flow rates at the inlet and outlet of the first fuel cell stack.

[0115] S419. Determine whether it is ready to shut down. If so, execute step S435; if not, execute step S420.

[0116] S420. Determine whether the difference between the flowmeters is less than 5%. If so, execute step S421; if not, return to step S418.

[0117] In this step, is the difference between the second flow rate detected by the second flowmeter and the fourth flow rate detected by the fourth flowmeter less than the preset difference?

[0118] S421, the shut-off valve 5(22) closes.

[0119] In this step, control the fifth shut-off valve to close.

[0120] S422, the water pump (27) stops working.

[0121] S423, the electromagnetic directional control valve 4(29) is in position 2.

[0122] In this step, the fourth electromagnetic directional control valve is in the second preset position.

[0123] S424, switch 1(36) connects to the positive electrode of the fuel cell stack 1(8).

[0124] In this step, control the positive electrode of the DC converter to connect to the positive electrode of the first fuel cell stack through the first switch.

[0125] S425, switch 2(37) connects to the negative electrode of the fuel cell stack 1(8).

[0126] In this step, the negative electrode of the DC converter connects to the negative electrode of the first fuel cell stack through the third switch.

[0127] S426, the electromagnetic directional control valves 1, 2(9, 12) are in position 1.

[0128] In this step, the first electromagnetic directional control valve and the second electromagnetic directional control valve are in the first preset position.

[0129] S427, the shut-off valve 2(3) closes.

[0130] In this step, control the second shut-off valve to close.

[0131] S428, the electromagnetic directional control valve 3(20) is in position 3.

[0132] In this step, the third electromagnetic directional control valve is in the third preset position.

[0133] S429, the flowmeters 1, 3(30, 32) record the flow rate.

[0134] In this step, the first flowmeter and the third flowmeter record the flow rates at the inlet and outlet of the second fuel cell stack.

[0135] S430, determine whether it is ready to shut down. If yes, execute step S435; if no, execute step S431.

[0136] S431, determine whether the difference between the flowmeters is less than 5%. If yes, execute step S432; if no, return to step S429.

[0137] In this step, it is determined whether the difference between the first flow rate detected by the first flowmeter and the third flow rate detected by the third flowmeter is less than a preset difference.

[0138] S432, the shut-off valve 4 (21) is closed.

[0139] In this step, the fourth shut-off valve is controlled to close.

[0140] S433, it is judged whether a single stack is working. If yes, step S434 is executed; if no, step S450 is executed.

[0141] In this step, whether the first fuel cell stack or the second fuel cell stack is in a working state.

[0142] S434, the FCCU switches to a dual-stack supply strategy.

[0143] S435, the air compressor 1 (28) works.

[0144] In this step, the first air compressor works.

[0145] S436, it is judged whether stack 1 is in a shutdown state. If yes, step S437 is executed; if no, step S451 is executed.

[0146] In this step, the first fuel cell stack is in a non-working state.

[0147] S437, the shut-off valves 1 and 5 (4, 22) are opened.

[0148] In this step, the first shut-off valve and the fifth shut-off valve are controlled to open.

[0149] S438, the electromagnetic directional valves 1 and 2 (9, 12) are in the 2 position.

[0150] In this step, the first electromagnetic directional valve and the second electromagnetic directional valve are in the second preset position.

[0151] S439, the electromagnetic directional valve 4 (29) is in the 1 position.

[0152] In this step, the fourth electromagnetic directional valve is in the first preset position.

[0153] S440, the water content of stack 1 (8) is collected.

[0154] In this step, the water content of the first fuel cell stack is obtained.

[0155] S441, the CVP collects the single-cell voltage data.

[0156] In this step, the single-cell voltage data of the first fuel cell stack is obtained.

[0157] S442. Determine whether the fuel cell stack 1 is in a flooded state. If so, return to step S440; if not, execute step S443.

[0158] In this step, determine whether the first fuel cell stack is in a flooded state according to the water content of the first fuel cell stack.

[0159] S443. Switch 1 (36) connects to the positive electrode of the fuel cell stack 1 (8).

[0160] In this step, control the positive electrode of the DC converter to connect to the positive electrode of the first fuel cell stack through the first switch.

[0161] S444. Switch 2 (37) connects to the negative electrode of the fuel cell stack 2 (7).

[0162] In this step, the negative electrode of the DC converter connects to the negative electrode of the second fuel cell stack through the third switch.

[0163] S445. Switch 3 (38) closes.

[0164] In this step, the second switch closes.

[0165] S446. Determine whether the single-cell voltage has returned to normal. If so, execute step S447; if not, return to step S441.

[0166] In this step, determine whether the single-cell voltage data of the first fuel cell stack is normal.

[0167] S447. The electromagnetic directional valve 3 (20) is in position 2.

[0168] In this step, control the third electromagnetic steering valve to be in the second preset position.

[0169] S448. The air compressor 1 (28) stops working.

[0170] In this step, the first air compressor stops working.

[0171] S449. The electromagnetic directional valve 4 (29) is in position 2.

[0172] In this step, the fourth electromagnetic steering valve is in the second preset position.

[0173] S450. The FCCU switches to the dual-stack supply strategy.

[0174] S451. The shut-off valves 2 and 4 (3 and 21) open.

[0175] In this step, control the second shut-off valve and the fourth shut-off valve to open.

[0176] S452, the electromagnetic directional control valves 1 and 2 (9 and 12) are in the 2 position.

[0177] In this step, control the first electromagnetic directional control valve and the second electromagnetic directional control valve to be in the second preset position.

[0178] S453, the electromagnetic directional control valve 4 (29) is in the 1 position.

[0179] In this step, the fourth electromagnetic directional control valve is in the first preset position.

[0180] S454, collect the water content of the fuel cell stack 2 (7).

[0181] In this step, obtain the water content of the second fuel cell stack.

[0182] S455, the CVP collects the single-cell voltage data.

[0183] In this step, obtain the single-cell voltage data of the second fuel cell stack.

[0184] S456, determine whether the fuel cell stack 2 is in a flooded state. If so, return to step S454; if not, execute step S457.

[0185] In this step, determine whether the second fuel cell stack is in a flooded state according to the water content of the second fuel cell stack.

[0186] S457, switch 1 (36) is connected to the positive electrode of the fuel cell stack 1 (8).

[0187] In this step, control the positive electrode of the DC converter to be connected to the positive electrode of the first fuel cell stack through the first switch.

[0188] S458, switch 2 (37) is connected to the negative electrode of the fuel cell stack 2 (7).

[0189] In this step, the negative electrode of the DC converter is connected to the negative electrode of the second fuel cell stack through the third switch.

[0190] S459, switch 3 (38) is closed.

[0191] In this step, the second switch is closed.

[0192] S460, determine whether the single-cell voltage has returned to normal. If so, return to step S447; if not, return to step S455.

[0193] In this step, determine whether the single-cell voltage data of the second fuel cell stack is normal.

[0194] S461, determine whether to prepare for shutdown. If so, return to step S405; if not, execute step S462.

[0195] S462, Normal shutdown process.

[0196] S463, Shut-off valves (3, 4, 19, 21, 22) are closed.

[0197] In this step, control the first shut-off valve, the second shut-off valve, the third shut-off valve, the fourth shut-off valve and the fifth shut-off valve to close.

[0198] In summary, the control method of the fuel cell system according to the embodiment of the present invention includes: determining whether the fuel cell system is in an idle condition; in response to the fuel cell system being in an idle condition, determining whether both the first fuel cell stack and the second fuel cell stack are in a working state; in response to both the first fuel cell stack and the second fuel cell stack being in a working state, controlling the first shut-off valve, the second shut-off valve, the water pump, the first switch, the second switch, the third switch, the first electromagnetic reversing valve, the second electromagnetic reversing valve, the third electromagnetic reversing valve and the fourth electromagnetic reversing valve according to the remaining service lives of the first fuel cell stack and the second fuel cell stack, so that either the first fuel cell stack or the second fuel cell stack is in a non-working state. Thus, this method reduces the idle power of the fuel cell system to meet the vehicle idle power constraint requirements and voltage requirements. Under the idle condition, the operation changes from multiple fuel cell stacks working to a single fuel cell stack working. On this basis, the current density can be increased to reduce the average single cell voltage to be lower than 0.85V. The single fuel cell stack working can also ensure that the output power is lower than the vehicle idle power constraint requirements. By the method of injecting water to suspend the operation of the fuel cell stack, the generation of the hydrogen-air interface is avoided, the attenuation damage of the fuel cell stack caused by the method of suspending the operation is reduced, the hydrogen consumption is reduced, and the service life of the fuel cell stack is increased.

[0199] It should be noted that some embodiments of the present invention are described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in a different order from those in the above embodiments and still achieve the desired results. Additionally, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0200] Corresponding to the above embodiments, the present invention also proposes a control device for a fuel cell system.

[0201] As Figure 5 shown, the control device for the fuel cell system according to the embodiment of the present invention includes: a determination module 510, a first response module 520 and a second response module 530.

[0202] Among them, a determination module 510 is configured to determine whether the fuel cell system is in an idle condition; a first response module 520 is configured to determine whether both the first fuel cell stack and the second fuel cell stack are in an operating state in response to the fuel cell system being in the idle condition; a second response module 530 is configured to control a first shut-off valve, a second shut-off valve, a water pump, a first switch, a second switch, a third switch, a first electromagnetic directional valve, a second electromagnetic directional valve, a third electromagnetic directional valve, and a fourth electromagnetic directional valve according to the remaining service lives of the first fuel cell stack and the second fuel cell stack in response to both the first fuel cell stack and the second fuel cell stack being in the operating state, so that either the first fuel cell stack or the second fuel cell stack is in a non-operating state.

[0203] In some embodiments of the present invention, before determining whether the fuel cell system is in the idle condition, the second response module 530 is further configured to control the opening of the first shut-off valve, the second shut-off valve, the third shut-off valve, the fourth shut-off valve, and the fifth shut-off valve, control the first electromagnetic directional valve, the second electromagnetic directional valve, the third electromagnetic directional valve, and the fourth electromagnetic directional valve to be in a second preset position, and control the water pump to be closed.

[0204] In some embodiments of the present invention, the second response module 530 controls the first shut-off valve, the second shut-off valve, the water pump, the first switch, the second switch, the third switch, the first electromagnetic directional valve, the second electromagnetic directional valve, the third electromagnetic directional valve, and the fourth electromagnetic directional valve according to the remaining service lives of the first fuel cell stack and the second fuel cell stack, so that either the first fuel cell stack or the second fuel cell stack is in a non-operating state. Specifically, it is configured to control the fourth electromagnetic directional valve to be in a third preset position, control the water pump to be turned on, and control the third switch to be turned off; calculate a first remaining service life of the first fuel cell stack and a second remaining service life of the second fuel cell stack, and compare the magnitudes of the first remaining service life and the second remaining service life; in response to the first remaining service life being lower than the second remaining service life, control the positive pole of the DC converter to be connected to the positive pole of the second fuel cell stack through the first switch, control the negative pole of the DC converter to be connected to the negative pole of the second fuel cell stack through the third switch, control the first electromagnetic directional valve and the second electromagnetic directional valve to be in the third preset position, control the third electromagnetic directional valve to be in the first preset position, and control the first shut-off valve to be closed.

[0205] In some embodiments of the present invention, the second response module 530 is further configured to, in response to the second remaining service life being lower than the first remaining service life, control the positive pole of the DC converter to be connected to the positive pole of the first fuel cell stack through the first switch, control the negative pole of the DC converter to be connected to the negative pole of the first fuel cell stack through the third switch, control the first electromagnetic directional valve and the second electromagnetic directional valve to be in the first preset position, control the third electromagnetic directional valve to be in the third preset position, and control the second shut-off valve to be closed.

[0206] In some embodiments of the present invention, the second response module 530 is further configured to determine whether the difference between the second flow rate detected by the second flowmeter and the fourth flow rate detected by the fourth flowmeter is less than a preset difference; in response to the difference between the second flow rate and the fourth flow rate being less than the preset difference, control the fifth shut-off valve to close, control the water pump to stop working, and control the fourth electromagnetic directional valve to be in the second preset position.

[0207] In some embodiments of the present invention, the second response module 530 is further configured to determine whether the difference between the first flow rate detected by the first flowmeter and the third flow rate detected by the third flowmeter is less than a preset difference; in response to the difference between the first flow rate and the third flow rate being less than the preset difference, control the fourth shut-off valve to close, control the water pump to stop working, and control the fourth electromagnetic directional valve to be in the second preset position.

[0208] In some embodiments of the present invention, the second response module 530 is further configured to, in response to the fuel cell system being in a non-idle condition, determine whether both the first fuel cell stack and the second fuel cell stack are in an operating state; in response to the first fuel cell stack or the second fuel cell stack being in a non-operating state, control the first air compressor to operate; control the first shut-off valve, the second shut-off valve, the fourth shut-off valve, the fifth shut-off valve, the first switch, the second switch, and the third switch according to the operating powers of the first fuel cell stack and the second fuel cell stack, and control the first electromagnetic directional valve, the second electromagnetic directional valve, and the fourth electromagnetic directional valve, so that both the first fuel cell stack and the second fuel cell stack are in an operating state.

[0209] In some embodiments of the present invention, the second response module 530 controls the first shut-off valve, the second shut-off valve, the fourth shut-off valve, the fifth shut-off valve, the first switch, the second switch, and the third switch according to the operating powers of the first fuel cell stack and the second fuel cell stack, and controls the first electromagnetic reversing valve, the second electromagnetic reversing valve, and the fourth electromagnetic reversing valve to enable both the first fuel cell stack and the second fuel cell stack to be in an operating state. Specifically, it is configured to: determine the fuel cell stack in a non-operating state according to the operating powers of the first fuel cell stack and the second fuel cell stack; in response to the first fuel cell stack being in a non-operating state, control the first shut-off valve and the fifth shut-off valve to open, and control the first electromagnetic reversing valve and the second electromagnetic reversing valve to be in the second preset position and the fourth electromagnetic reversing valve to be in the first preset position; obtain the single-cell voltage data and the water content of the first fuel cell stack, and determine whether the first fuel cell stack is in a flooded state according to the water content of the first fuel cell stack; in response to the first fuel cell stack not being in a flooded state, control the positive pole of the DC converter to be connected to the positive pole of the first fuel cell stack through the first switch, the negative pole of the DC converter to be connected to the negative pole of the second fuel cell stack through the third switch, and the second switch to be closed; determine whether the single-cell voltage data of the first fuel cell stack is normal; in response to the single-cell voltage data of the first fuel cell stack being normal, control the third electromagnetic steering valve to be in the second preset position and the fourth electromagnetic steering valve to be in the second preset position, and control the first air compressor to stop working.

[0210] In some embodiments of the present invention, the second response module 530 is further configured to, in response to the second fuel cell stack being in a non-operating state, control the second shut-off valve and the fourth shut-off valve to open, and control the first electromagnetic reversing valve and the second electromagnetic reversing valve to be in the second preset position and the fourth electromagnetic reversing valve to be in the first preset position; obtain the single-cell voltage data and the water content of the second fuel cell stack, and determine whether the second fuel cell stack is in a flooded state according to the water content of the second fuel cell stack; in response to the second fuel cell stack not being in a flooded state, control the positive pole of the DC converter to be connected to the positive pole of the first fuel cell stack through the first switch, the negative pole of the DC converter to be connected to the negative pole of the second fuel cell stack through the third switch, and the second switch to be closed; determine whether the single-cell voltage data of the second fuel cell stack is normal; in response to the single-cell voltage data of the second fuel cell stack being normal, control the third electromagnetic steering valve to be in the second preset position and the fourth electromagnetic steering valve to be in the second preset position, and control the first air compressor to stop working.

[0211] It should be noted that for the details not disclosed in the control device of the fuel cell system in the embodiments of the present invention, please refer to the details disclosed in the control method of the fuel cell system in the embodiments of the present invention, and will not be elaborated herein.

[0212] In summary, the control device of the fuel cell system according to the embodiment of the present invention includes: a determination module configured to determine whether the fuel cell system is in an idle condition; a first response module configured to, in response to the fuel cell system being in the idle condition, determine whether both the first fuel cell stack and the second fuel cell stack are in a working state; a second response module configured to, in response to both the first fuel cell stack and the second fuel cell stack being in the working state, control a first shut-off valve, a second shut-off valve, a water pump, a first switch, a second switch, a third switch, a first electromagnetic reversing valve, a second electromagnetic reversing valve, a third electromagnetic reversing valve, and a fourth electromagnetic reversing valve according to the remaining service lives of the first fuel cell stack and the second fuel cell stack, so that either the first fuel cell stack or the second fuel cell stack is in a non-working state. Thus, the present device reduces the idle power of the fuel cell system to meet the vehicle idle power constraint requirements and voltage requirements. In the idle condition, the operation changes from multiple fuel cell stacks working to a single fuel cell stack working. On this basis, the current density can be increased to reduce the average single-cell voltage to be lower than 0.85V. The single fuel cell stack working can also ensure that the output power is lower than the vehicle idle power constraint requirements. By the method of injecting water to shut down the stack, the generation of the hydrogen-air interface is avoided, the attenuation damage of the stack caused by the stack shutdown method is reduced, the hydrogen consumption is reduced, and the service life of the fuel cell stack is increased.

[0213] For the convenience of description, when describing the above system, various modules are separately described according to their functions. Of course, when implementing the present invention, the functions of each module can be implemented in one or more pieces of software and / or hardware.

[0214] The system of the above embodiment is used to implement the corresponding method in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be elaborated herein.

[0215] In addition, although the operations of the method of the present invention are described in a specific order in the drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. On the contrary, the steps depicted in the flowchart can be changed in the order of execution. Additionally or alternatively, some steps can be omitted, multiple steps can be combined into one step for execution, and / or one step can be decomposed into multiple steps for execution.

[0216] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present invention should have the ordinary meanings understood by those of ordinary skill in the art to which the present invention pertains. The "first", "second" and similar terms used in the embodiments of the present invention do not denote any order, quantity or importance, but are only used to distinguish different components. Words such as "comprising" or "including" mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0217] Although the spirit and principles of the present invention have been described with reference to several specific embodiments, it should be understood that the present invention is not limited to the specific embodiments disclosed, and the division of each aspect does not mean that the features in these aspects cannot be combined for benefits. Such division is only for the convenience of expression. The present invention aims 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 accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A control method for a fuel cell system, characterized in that: include: Determining whether the fuel cell system is in an idle condition; In response to the fuel cell system being in an idle state, determining whether the first fuel cell stack and the second fuel cell stack are both in an operating state; In response to the first fuel cell stack and the second fuel cell stack being in an operating state, the first shut-off valve, the second shut-off valve, the water pump, the first switch, the second switch, the third switch, the first solenoid reversing valve, the second solenoid reversing valve, the third solenoid reversing valve and the fourth solenoid reversing valve are controlled according to the remaining life of the first fuel cell stack and the second fuel cell stack to put the first fuel cell stack or the second fuel cell stack into a non-operating state.

2. The control method of the fuel cell system according to claim 1, characterized in that: Before determining whether the fuel cell system is in an idle condition, the method further includes: Control to open the first shut-off valve, the second shut-off valve, the third shut-off valve, the fourth shut-off valve and the fifth shut-off valve, control the first solenoid reversing valve, the second solenoid reversing valve, the third solenoid reversing valve and the fourth solenoid reversing valve to be located at the second preset position, and control to shut down the water pump.

3. The control method of the fuel cell system according to claim 2, characterized in that: The method of controlling the first shutoff valve, the second shutoff valve, the water pump, the first switch, the second switch, the third switch, the first electromagnetic reversing valve, the second electromagnetic reversing valve, the third electromagnetic reversing valve and the fourth electromagnetic reversing valve according to the remaining life of the first fuel cell stack and the second fuel cell stack so as to put the first fuel cell stack or the second fuel cell stack in a non-working state includes: Control the fourth electromagnetic reversing valve to be located at a third preset position, control the water pump to start, and control the third switch to be disconnected; Calculating a first remaining life of the first fuel cell stack and a second remaining life of the second fuel cell stack, and comparing the first remaining life and the second remaining life; In response to the first remaining life being lower than the second remaining life, the positive electrode of the DC converter is controlled to be connected to the positive electrode of the second fuel cell stack through the first switch, and the negative electrode of the DC converter is connected to the negative electrode of the second fuel cell stack through the third switch, the first solenoid reversing valve and the second solenoid reversing valve are controlled to be located at the third preset position, and the third solenoid reversing valve is controlled to be located at the first preset position, and the first shut-off valve is controlled to be closed.

4. The control method of the fuel cell system according to claim 3, characterized in that: The method further comprises: In response to the second remaining life being lower than the first remaining life, the positive electrode of the DC converter is controlled to be connected to the positive electrode of the first fuel cell stack through the first switch, and the negative electrode of the DC converter is connected to the negative electrode of the first fuel cell stack through the third switch, the first solenoid reversing valve and the second solenoid reversing valve are controlled to be located at the first preset position, and the third solenoid reversing valve is controlled to be located at the third preset position, and the second shut-off valve is controlled to be closed.

5. The control method of the fuel cell system according to claim 3, characterized in that: The method further comprises: Determine whether a difference between a second flow rate detected by the second flow meter and a fourth flow rate detected by the fourth flow meter is less than a preset difference; In response to the difference between the second flow rate and the fourth flow rate being smaller than the preset difference value, the fifth shut-off valve is controlled to be closed, the water pump is controlled to stop working, and the fourth electromagnetic reversing valve is controlled to be located at the second preset position.

6. The control method of the fuel cell system according to claim 2, characterized in that: The method further comprises: Determine whether a difference between a first flow rate detected by the first flow meter and a third flow rate detected by the third flow meter is less than a preset difference; In response to the difference between the first flow rate and the third flow rate being smaller than the preset difference value, the fourth shut-off valve is controlled to be closed, the water pump is controlled to stop working, and the fourth electromagnetic reversing valve is controlled to be located at the second preset position.

7. The control method of the fuel cell system according to claim 2, characterized in that: The method further comprises: In response to the fuel cell system being in a non-idle operating state, determining whether the first fuel cell stack and the second fuel cell stack are both in an operating state; In response to the first fuel cell stack or the second fuel cell stack being in a non-operating state, controlling the first air compressor to operate; According to the working power of the first fuel cell stack and the second fuel cell stack, the first shut-off valve, the second shut-off valve, the fourth shut-off valve, the fifth shut-off valve, the first switch, the second switch and the third switch are controlled, and the first solenoid reversing valve, the second solenoid reversing valve and the fourth solenoid reversing valve are controlled to make the first fuel cell stack and the second fuel cell stack both in working state.

8. The control method of the fuel cell system according to claim 7, characterized in that: The method controls the first shutoff valve, the second shutoff valve, the fourth shutoff valve, the fifth shutoff valve, the first switch, the second switch and the third switch according to the working power of the first fuel cell stack and the second fuel cell stack, and controls the first electromagnetic reversing valve, the second electromagnetic reversing valve and the fourth electromagnetic reversing valve, so that the first fuel cell stack and the second fuel cell stack are both in working state, including: Determine a fuel cell stack in a non-operating state according to the operating power of the first fuel cell stack and the second fuel cell stack; In response to the first fuel cell stack being in a non-operating state, controlling the first shutoff valve and the fifth shutoff valve to open, controlling the first solenoid reversing valve and the second solenoid reversing valve to be located at the second preset position, and controlling the fourth solenoid reversing valve to be located at the first preset position; Acquiring single-chip voltage data and water content of the first fuel cell stack, and determining whether the first fuel cell stack is in a water-flooded state according to the water content of the first fuel cell stack; In response to the first fuel cell stack not being in a flooded state, controlling the positive electrode of the DC converter to be connected to the positive electrode of the first fuel cell stack through a first switch, the negative electrode of the DC converter to be connected to the negative electrode of the second fuel cell stack through a third switch, and the second switch to be closed; Determining whether the single-chip voltage data of the first fuel cell stack is normal; In response to the single-chip voltage data of the first fuel cell stack being normal, the third electromagnetic steering valve is controlled to be located at the second preset position, the fourth electromagnetic steering valve is controlled to be located at the second preset position, and the first air compressor is controlled to stop working.

9. The control method of the fuel cell system according to claim 8, characterized in that: The method further comprises: In response to the second fuel cell stack being in a non-operating state, controlling the second shutoff valve and the fourth shutoff valve to open, controlling the first solenoid reversing valve and the second solenoid reversing valve to be located at the second preset position, and controlling the fourth solenoid reversing valve to be located at the first preset position; Acquiring single-chip voltage data and water content of the second fuel cell stack, and determining whether the second fuel cell stack is in a water-flooded state according to the water content of the second fuel cell stack; In response to the second fuel cell stack not being in a flooded state, controlling the positive electrode of the DC converter to be connected to the positive electrode of the first fuel cell stack through a first switch, the negative electrode of the DC converter to be connected to the negative electrode of the second fuel cell stack through a third switch, and the second switch to be closed; Determining whether the single-chip voltage data of the second fuel cell stack is normal; In response to the single-chip voltage data of the second fuel cell stack being normal, the third electromagnetic steering valve is controlled to be located at the second preset position, the fourth electromagnetic steering valve is controlled to be located at the second preset position, and the first air compressor is controlled to stop working.

10. A control device for a fuel cell system, characterized in that: include: A determination module, configured to determine whether the fuel cell system is in an idle condition; A first response module is configured to determine whether the first fuel cell stack and the second fuel cell stack are both in a working state in response to the fuel cell system being in an idle state; The second response module is configured to control the first shut-off valve, the second shut-off valve, the water pump, the first switch, the second switch, the third switch, the first solenoid reversing valve, the second solenoid reversing valve, the third solenoid reversing valve and the fourth solenoid reversing valve in response to the first fuel cell stack and the second fuel cell stack being in a working state according to the remaining life of the first fuel cell stack and the second fuel cell stack, so as to put the first fuel cell stack or the second fuel cell stack into a non-working state.

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