Anode supply variable configuration multi-stack fuel cell system and control method thereof

Abstract

The application discloses an anode-supplied variable-configuration multi-stack fuel cell system and a control method thereof, and relates to the field of fuel cells. The control method comprises the following steps: sequentially switching the operation mode of the multi-stack fuel cell system into a first hydrogen supply mode, a second hydrogen supply mode, a third hydrogen supply mode and a fourth hydrogen supply mode until a variation number is reached; when the operation time reaches a hydrogen supply pulsation hydrogen discharge interval, the current hydrogen supply operation state is detected, the hydrogen discharge mode corresponding to the current hydrogen supply mode is switched to, and the operation time of the corresponding hydrogen discharge mode is satisfied until the hydrogen discharge purging time; when a shutdown instruction is received, the operation mode of the multi-stack fuel cell system is switched to the third hydrogen discharge mode, all electromagnetic valves are closed after the first fuel cell stack and the second fuel cell stack are purged for 3 seconds, and the multi-stack fuel cell system enters a shutdown state. The application improves the efficiency and service life of the multi-stack fuel cell system by dynamically switching the series-parallel operation mode.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fuel cell, in particular to an anode supply variable configuration multi-stack fuel cell system and a control method thereof. BACKGROUND

[0002] Fuel cells, as a kind of high-efficiency and clean energy conversion device, have broad application prospects in the field of new energy. Hydrogen deficiency and water flooding are two main factors leading to the performance deterioration of proton exchange membrane fuel cell stacks. For single fuel cell system (SFCS), it has been shown that hydrogen pressure pulsed fueling (HPPF) can significantly affect the transport phenomenon of hydrogen and water in the anode flow field. In the face of high-power and super-power power generation demand, single fuel cell cannot meet the demand, and there are technical bottlenecks and limitations. Compared with SFCS, multi-stack fuel cell system (MFCS) has the advantages of modular expansion and redundant reliability. Through the coordinated operation of multiple stacks, the system can realize flexible power adjustment, has higher efficiency than single stack at high power, and can significantly reduce the risk of system failure.

[0003] For different application scenarios of MFCS, the hydrogen and air circuit has series and parallel structure. The series structure has simple control, good performance consistency, but poor reliability and low power regulation flexibility. The parallel structure has high reliability, high fault tolerance, long service life and strong expansion, but the control is complex. MFCS is more complex than SFCS. It not only needs to ensure the dynamic matching of the exhaust strategy of each stack and the output demand, but also needs to coordinate the gas distribution between the stacks. The ultimate goal is to achieve the expected output power of MFCS while ensuring controllable pressure fluctuation between the stacks and system stability. The traditional multi-stack fuel cell system purging strategy is difficult to dynamically adapt to load changes, resulting in waste of hydrogen or incomplete removal, and the pressure shock and nitrogen enrichment problem under multi-stack coupling further affect the stability of the system. The existing technology mainly depends on single operation mode or preset parameter control, and cannot meet the requirements of efficiency, reliability and service life. SUMMARY

[0004] In order to solve the above problems, the present application provides an anode supply variable configuration multi-stack fuel cell system and a control method thereof.

[0005] To achieve the above purpose, the present application provides the following solutions.

[0006] In a first aspect, the application provides an anode-supply-variable-configuration multi-stack fuel cell system, comprising: a hydrogen storage bottle, a first fuel cell stack, a second fuel cell stack, a hydrogen inlet electromagnetic valve group, a communication electromagnetic valve, a hydrogen outlet electromagnetic valve group, and a fuel cell control unit;

[0007] The hydrogen storage bottle is connected to the first fuel cell stack via a connection pipeline, and the hydrogen storage bottle is connected to the second fuel cell stack via a connection pipeline, and the hydrogen inlet electromagnetic valve group is arranged on the connection pipeline; the first fuel cell stack and the second fuel cell stack are connected via the communication electromagnetic valve; the hydrogen outlet electromagnetic valve group is arranged on both ends of the first fuel cell stack and both ends of the second fuel cell stack;

[0008] The hydrogen inlet electromagnetic valve group, the hydrogen outlet electromagnetic valve group, and the communication electromagnetic valve are connected to the fuel cell control unit; the fuel cell control unit is used to control the hydrogen inlet electromagnetic valve group, the hydrogen outlet electromagnetic valve group, and the communication electromagnetic valve, and switch the operation mode of the multi-stack fuel cell system; the operation mode includes a hydrogen series operation mode, a hydrogen parallel operation mode, and an independent operation mode.

[0009] In a second aspect, the application provides a control method of a cathode-supply-variable-configuration multi-stack fuel cell system, which is applied to the anode-supply-variable-configuration multi-stack fuel cell system described above, and the operation mode of the multi-stack fuel cell system includes a hydrogen series operation mode, a hydrogen parallel operation mode, and an independent operation mode; the hydrogen series operation mode includes a first hydrogen supply mode, a first hydrogen discharge mode, a second hydrogen supply mode, and a second hydrogen discharge mode; the hydrogen parallel operation mode includes a third hydrogen supply mode, a third hydrogen discharge mode, a fourth hydrogen supply mode, and a fourth hydrogen discharge mode; the independent operation mode includes a fifth hydrogen supply mode, a fifth hydrogen discharge mode, a sixth hydrogen supply mode, and a sixth hydrogen discharge mode;

[0010] The control method comprises:

[0011] Setting a hydrogen supply pulsating discharge interval, a hydrogen discharge purging time, a variation frequency of the operation mode in each hydrogen discharge cycle, and a running time of each hydrogen supply mode in the hydrogen series and parallel operation mode;

[0012] Switching the operation mode of the multi-stack fuel cell system to the first hydrogen supply mode, the second hydrogen supply mode, the third hydrogen supply mode, and the fourth hydrogen supply mode in sequence until the variation frequency is reached;

[0013] When the running time reaches the hydrogen supply pulsating discharge interval, the current hydrogen supply operation state is detected, and the hydrogen discharge mode corresponding to the current hydrogen supply mode is switched until the running time of the corresponding hydrogen discharge mode meets the hydrogen discharge purging time;

[0014] When receiving the shutdown instruction, the operation mode of the multi-stack fuel cell system is switched to a third hydrogen discharge mode, and after purging the first fuel cell stack and the second fuel cell stack for 3 seconds respectively, all the electromagnetic valves are closed, and the multi-stack fuel cell system enters a shutdown state.

[0015] According to the specific embodiments provided in the present application, the present application has the following technical effects.

[0016] (1) The present application controls the hydrogen inlet electromagnetic valve, the hydrogen discharge electromagnetic valve and the communication electromagnetic valve through the fuel cell control unit, and can realize the switching of the operation mode (hydrogen series operation mode, hydrogen parallel operation mode and independent operation mode) of the multi-stack fuel cell system. The present application fully combines the advantages of series and parallel operation modes, and this flexible switching mechanism can be dynamically adjusted according to real-time working conditions, taking into account power demand and stack life, and significantly improving the adaptability of the system in diversified scenarios (such as vehicle start-stop, distributed power generation load fluctuation).

[0017] (2) The present application switches the operation mode according to the set hydrogen supply pulsation discharge interval, hydrogen discharge purge time, number of operation mode changes in each hydrogen discharge period and operation time of each hydrogen supply mode in the hydrogen series and parallel operation mode. This periodic pulsation discharge strategy can form a controllable pressure pulsation in the anode flow field. This active disturbance can break the local stagnant area, accelerate hydrogen diffusion and water discharge, and effectively alleviate the water flooding problem. At the same time, after receiving the shutdown instruction, the third hydrogen discharge mode is executed, each fuel cell stack is purged for 3 seconds to remove residual gas and water, and the nitrogen and other inert gas accumulation is removed through pulsation purge to maintain the anode reaction activity. Compared with the traditional fixed parameter purge, the dynamic pulsation control can more accurately balance the mass transfer efficiency and hydrogen consumption, and prolong the service life of the stack. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0019] Figure 1 The structure schematic diagram of an anode supply variable configuration multi-stack fuel cell system in an embodiment of the present application.

[0020] Figure 2 The hydrogen series operation mode schematic diagram of the anode supply variable configuration multi-stack fuel cell system; wherein (a) is a first hydrogen supply mode schematic diagram, (b) is a first hydrogen discharge mode schematic diagram, (c) is a second hydrogen supply mode schematic diagram, and (d) is a second hydrogen discharge mode schematic diagram.

[0021] Figure 3 A schematic diagram of the parallel operation mode of a variable configuration multi-stack fuel cell system for supplying hydrogen to the anode; wherein, (a) is a schematic diagram of the third hydrogen supply mode, (b) is a schematic diagram of the third hydrogen discharge mode, (c) is a schematic diagram of the fourth hydrogen supply mode, and (d) is a schematic diagram of the fourth hydrogen discharge mode.

[0022] Figure 4 A schematic diagram of the independent operation modes of a variable configuration multi-stack fuel cell system for anode supply; wherein, (a) is a schematic diagram of the fifth hydrogen supply mode, (b) is a schematic diagram of the fifth hydrogen discharge mode, (c) is a schematic diagram of the sixth hydrogen supply mode, and (d) is a schematic diagram of the sixth hydrogen discharge mode.

[0023] Figure 5 This is a schematic diagram showing the changes in hydrogen and water vapor concentration curves in a fuel cell as the applied hydrogen pressure fluctuates.

[0024] Figure 6 This is a schematic flowchart illustrating a control method for a variable configuration multi-stack fuel cell system with anode supply according to an embodiment of this application.

[0025] Figure 7 A schematic diagram of a multi-stack fuel cell system with variable configuration for anode supply that does not change its operating mode during the hydrogen emission cycle.

[0026] Figure 8 A schematic diagram of a variable configuration multi-stack fuel cell system that changes its operating mode once during a hydrogen emission cycle. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] In one exemplary embodiment, a variable-configuration multi-stack fuel cell system with anode supply is provided. This multi-stack fuel cell system can be configured with multiple fuel cell stacks; this embodiment uses two stacks as an example. Figure 1As shown, the multi-stack fuel cell system comprises a hydrogen storage bottle 1, a first fuel cell stack 2, a second fuel cell stack 3, a hydrogen inlet electromagnetic valve group, a communication electromagnetic valve 6, a hydrogen outlet electromagnetic valve group and a fuel cell control unit (FCU) 17. The hydrogen inlet electromagnetic valve group comprises a first hydrogen inlet electromagnetic valve 4 and a second hydrogen inlet electromagnetic valve 5; the hydrogen outlet electromagnetic valve group comprises a first hydrogen outlet electromagnetic valve 7, a second hydrogen outlet electromagnetic valve 8, a third hydrogen outlet electromagnetic valve 9 and a fourth hydrogen outlet electromagnetic valve 10.

[0030] The first hydrogen inlet electromagnetic valve 4 is arranged on the connecting pipeline between the outlet of the hydrogen storage bottle 1 and the first fuel cell stack 2, and the second hydrogen inlet electromagnetic valve 5 is arranged on the connecting pipeline between the outlet of the hydrogen storage bottle 1 and the second fuel cell stack 3. The hydrogen storage bottle 1 is used to provide hydrogen required for the operation of the fuel cell stack, and the electrochemical reaction of hydrogen and oxygen is carried out in the fuel cell stack to realize energy conversion.

[0031] The first hydrogen inlet electromagnetic valve 4 and the second hydrogen inlet electromagnetic valve 5 belong to normally open electromagnetic valves, which are used to control the gas inlet direction of the fuel cell stack, and can adjust the hydrogen inlet pressure of the fuel cell stack according to the gas inlet demand of the fuel cell stack.

[0032] The first fuel cell stack 2 and the second fuel cell stack 3 are connected through the communication electromagnetic valve 6. The communication electromagnetic valve 6 belongs to a normally open electromagnetic valve, which is used to connect the gas inlet and outlet of the first fuel cell stack 2 and the second fuel cell stack 3, so that the fuel cell gas is more evenly distributed.

[0033] The first fuel cell stack 2 is provided with the first hydrogen outlet electromagnetic valve 7 and the second hydrogen outlet electromagnetic valve 8 at both ends, and the second fuel cell stack 3 is provided with the third hydrogen outlet electromagnetic valve 9 and the fourth hydrogen outlet electromagnetic valve 10 at both ends. The first hydrogen outlet electromagnetic valve 7 to the fourth hydrogen outlet electromagnetic valve 10 belong to normally closed pulse exhaust valves, which are used to remove the water and excess exhaust gas generated in the fuel cell stack, so as to prevent water flooding and performance degradation.

[0034] The hydrogen inlet electromagnetic valve group, the hydrogen outlet electromagnetic valve group and the communication electromagnetic valve 6 are connected with the fuel cell control unit 17; the fuel cell control unit 17 is used to control the hydrogen inlet electromagnetic valve group, the hydrogen outlet electromagnetic valve group and the communication electromagnetic valve 6, and switch the operation mode of the multi-stack fuel cell system; the operation mode includes hydrogen series operation mode (as shown in Figure 2 Figure 3 The hydrogen parallel operation mode (as shown in Figure 4 The independent operation mode (as shown in Figure 4 Since the opening and closing of the hydrogen inlet electromagnetic valve group and the hydrogen outlet electromagnetic valve group can control the hydrogen series and parallel supply mode of the multi-stack fuel cell system, the multi-stack fuel cell system provided by the embodiment is a variable anode supply multi-stack fuel cell system.

[0035] Specifically, the fuel cell control unit 17 controls the corresponding hydrogen inlet electromagnetic valve, the communication electromagnetic valve 6 and the hydrogen exhaust electromagnetic valve according to the set hydrogen supply pulsation exhaust interval , the hydrogen exhaust purge time , the number of changes of the operation mode in each hydrogen exhaust period , to realize dynamic switching of hydrogen series and parallel connection.

[0036] Specifically, as shown in (a)-(d) in Figure 2 , the hydrogen series operation mode (hydrogen series hydrogen supply and hydrogen series hydrogen exhaust) includes: a first hydrogen supply mode, a first hydrogen exhaust mode, a second hydrogen supply mode and a second hydrogen exhaust mode.

[0037] The first hydrogen supply mode (hydrogen supply mode I), the first hydrogen inlet electromagnetic valve 4 and the communication electromagnetic valve 6 are opened, and the remaining electromagnetic valves are all closed.

[0038] The first hydrogen exhaust mode (hydrogen exhaust mode I), the first hydrogen inlet electromagnetic valve 4, the communication electromagnetic valve 6 and the fourth hydrogen exhaust electromagnetic valve 10 are opened, and the remaining electromagnetic valves are all closed.

[0039] The second hydrogen supply mode (hydrogen supply mode II), the second hydrogen inlet electromagnetic valve 5 and the communication electromagnetic valve 6 are opened, and the remaining electromagnetic valves are all closed.

[0040] The second hydrogen exhaust mode (hydrogen exhaust mode II), the second hydrogen inlet electromagnetic valve 5, the communication electromagnetic valve 6 and the first hydrogen exhaust electromagnetic valve 7 are opened, and the remaining electromagnetic valves are all closed.

[0041] The four hydrogen series operation modes can switch the inlets and outlets of the two fuel cell stacks back and forth, and the mass transfer rate of the substances in the anode channel is effectively improved by periodic pulsation. Hydrogen flows through the two fuel cell stacks in turn through the series pipeline, and the upstream stack outlet pressure is used to drive the upstream stack inlet, which reduces the energy consumption of the circulating pump, but needs to avoid the risk of local water flooding caused by pressure accumulation. Hydrogen passing through the first fuel cell stack 2 into the second fuel cell stack 3 can also improve the gas humidity, thereby improving the overall performance of the system.

[0042] Specifically, as shown in (a)-(d) in Figure 3 , the hydrogen parallel operation mode (hydrogen parallel hydrogen supply and hydrogen parallel hydrogen exhaust) includes: a third hydrogen supply mode, a third hydrogen exhaust mode, a fourth hydrogen exhaust mode and a fourth hydrogen exhaust mode.

[0043] The third hydrogen supply mode (hydrogen supply mode III), the first hydrogen inlet electromagnetic valve 4 and the second hydrogen inlet electromagnetic valve 5 are opened, and the remaining electromagnetic valves are all closed.

[0044] The third hydrogen exhaust mode (hydrogen exhaust mode III), the first hydrogen inlet electromagnetic valve 4, the second hydrogen inlet electromagnetic valve 5, the second hydrogen exhaust electromagnetic valve 8 and the third hydrogen exhaust electromagnetic valve 9 are opened, and the remaining electromagnetic valves are all closed.

[0045] In the fourth hydrogen supply mode (hydrogen supply mode IV), the first hydrogen inlet solenoid valve 4, the second hydrogen inlet solenoid valve 5, and the connecting solenoid valve 6 are opened, while all other solenoid valves are closed.

[0046] In the fourth hydrogen discharge mode (hydrogen discharge mode IV), the first hydrogen inlet solenoid valve 4, the second hydrogen inlet solenoid valve 5, the connecting solenoid valve 6, and the third hydrogen discharge solenoid valve 9 are opened, while all other solenoid valves are closed.

[0047] In the four parallel hydrogen operation modes, hydrogen can be distributed to each fuel cell stack through independent branches, reducing coupling interference between stacks and improving power distribution flexibility. However, the issue of branch flow balancing needs to be addressed. Using the parallel hydrogen operation mode under low load or dynamic fluctuation conditions can effectively avoid the adverse conditions of high potential in multi-stack fuel cell systems under low load, thus extending the lifespan of the fuel cells.

[0048] Specifically, such as Figure 4 As shown in (a)-(d), the independent operation modes (independent hydrogen supply and independent hydrogen discharge) include: the fifth hydrogen supply mode, the fifth hydrogen discharge mode, the sixth hydrogen supply mode and the sixth hydrogen discharge mode.

[0049] In the fifth hydrogen supply mode (hydrogen supply mode V), the first hydrogen inlet solenoid valve 4 is opened, and all other solenoid valves are closed.

[0050] In the fifth hydrogen discharge mode (hydrogen discharge mode V), the first hydrogen inlet solenoid valve 4 and the second hydrogen discharge solenoid valve 8 are opened, and all other solenoid valves are closed.

[0051] In the sixth hydrogen supply mode (hydrogen supply mode VI), the second hydrogen inlet solenoid valve 5 is opened, and all other solenoid valves are closed.

[0052] In the sixth hydrogen discharge mode (hydrogen discharge mode VI), the second hydrogen inlet solenoid valve 5 and the third hydrogen discharge solenoid valve 9 are opened, and all other solenoid valves are closed.

[0053] The first fuel cell stack 2 or the second fuel cell stack 3 can operate independently in four independent operating modes. Even if one stack fails during operation, the other stack can continue to operate normally. In addition, in low-power mode, operating only one stack can meet the power requirements, and the system efficiency is higher.

[0054] Therefore, the above-mentioned multi-stack fuel cell system has a total of 12 operating modes, including 6 hydrogen supply modes and 6 hydrogen discharge modes.

[0055] like Figure 1As shown, the anode variable configuration multi-stack fuel cell system provided by the embodiment further comprises a first hydrogen pressure sensor 11, a second hydrogen pressure sensor 12, a third hydrogen pressure sensor 13, a fourth hydrogen pressure sensor 14, a first voltage sensor 15 and a second voltage sensor 16.

[0056] The first hydrogen pressure sensor 11 and the second hydrogen pressure sensor 12 are respectively arranged at two ends of the first fuel cell stack 2, and are used to collect the inlet hydrogen pressure and the outlet hydrogen pressure of the first fuel cell stack 2.

[0057] The third hydrogen pressure sensor 13 and the fourth hydrogen pressure sensor 14 are respectively arranged at two ends of the second fuel cell stack 3, and are used to collect the inlet hydrogen pressure and the outlet hydrogen pressure of the second fuel cell stack 3.

[0058] The first voltage sensor 15 is arranged on the first fuel cell stack, and is used to collect the stack voltage of the first fuel cell stack 2. The second voltage sensor 16 is arranged on the second fuel cell stack 3, and is used to collect the stack voltage of the second fuel cell stack 3.

[0059] The fuel cell control unit 17 is connected with the first hydrogen pressure sensor 11, the second hydrogen pressure sensor 12, the third hydrogen pressure sensor 13, the fourth hydrogen pressure sensor 14, the first voltage sensor 15 and the second voltage sensor 16, and is used to determine whether the first fuel cell stack 2 and the second fuel cell stack 3 are abnormal stacks according to the inlet hydrogen pressure, the outlet hydrogen pressure and the stack voltage of the first fuel cell stack 2 and the second fuel cell stack 3, and control the abnormal stack to stop working and start the independent operation mode.

[0060] Specifically, when the fuel cell control unit 17 detects that the inlet hydrogen pressure, the outlet hydrogen pressure and the stack voltage of one of the fuel cell stacks are all lower than the normal value, it is determined that the stack is an abnormal stack, and then the abnormal stack is controlled to stop working and the independent operation mode (hydrogen supply mode V or VI, hydrogen discharge mode V or VI) is started, so as to improve the fault tolerance of the system.

[0061] In a more specific embodiment, hydrogen pressure pulsation supply can significantly affect the transport phenomena of hydrogen and water in the anode flow field. The liquid saturated water in the fuel cell anode The change relationship is as follows:

[0062]

[0063]

[0064] wherein, represents the direction along the thickness of the gas diffusion layer from the interface between the channel and the gas diffusion layer (GDL); is the evaporation rate; is the saturated vapor pressure of water, which is related to temperature; is the current water vapor partial pressure; is the volumetric condensation coefficient; is the porosity of the GDL; is the effective area; is the molar mass of water vapor; is the liquid density; is the molecular weight of water vapor; is the ideal gas constant; is the fuel cell operating temperature. The pulsation can make the concentration of the substance evenly dispersed, the pulsation effect makes the water vapor concentration near the anode outlet smaller, the liquid saturated water concentration decreases, and the hydrogen concentration distribution is more uniform, so that the voltage decay rate of the fuel cell stack is also slowed down, and the performance of the multi-stack fuel cell system is improved.

[0065] As shown in Figure 5 , in the dead-end mode, as the partial pressure of water vapor is higher than the saturated pressure in this area, liquid water begins to form and accumulate near the outlet of the channel, resulting in a large water concentration at the anode hydrogen outlet of the fuel cell stack, and the liquid water can block the porous layer, causing the voltage to start to decay. The pulsation effect can effectively improve the gas diffusion, which helps to diffuse the water vapor near the outlet to the inlet, thereby prolonging the water condensation process, effectively reducing the water concentration distribution and improving the hydrogen concentration distribution, thereby helping to improve the efficiency of the multi-stack fuel cell system. Figure 5 The water concentration and hydrogen concentration distribution curves in the fuel cell flow channel under different anode operating modes are compared. In the traditional dead-end operating mode, the water concentration distribution curve in the anode flow channel is higher, and in comparison, the water concentration in the flow channel is significantly reduced after using hydrogen pressure pulsation control, which can effectively alleviate the water flooding problem. At the same time, after applying hydrogen pressure, the hydrogen concentration distribution in the entire flow channel is more uniform, which can ensure efficient supply of reactants and promote full electrochemical reaction, thereby improving the output performance and operating stability of the fuel cell.

[0066] In an exemplary embodiment, a control method of an anode supply variable configuration multi-stack fuel cell system is provided, which is applied to the anode supply variable configuration multi-stack fuel cell system described above. As shown in Figure 6 , the control method comprises the following steps.

[0067] S1. Set the hydrogen supply pulsation hydrogen removal interval , the hydrogen removal purge time , the number of changes in operating mode within each hydrogen removal period , and the operating time of each hydrogen supply mode in the hydrogen supply mode. Specifically, the operating time of hydrogen supply mode I the running time of the hydrogen supply mode II the running time of the hydrogen supply mode III the running time of the hydrogen supply mode IV T= + + + .

[0068] S2. Switch the running mode of the multi-stack fuel cell system to the first hydrogen supply mode, the second hydrogen supply mode, the third hydrogen supply mode and the fourth hydrogen supply mode in sequence until the number of changes is reached.

[0069] Specifically, the hydrogen supply modes I, II, III and IV of the multi-stack fuel cell system are alternately replaced, and the number of alternately replacing times satisfies .

[0070] S3. When the running time reaches the hydrogen supply pulsation exhaust interval , the current hydrogen supply running state is detected, and the running mode of the multi-stack fuel cell system is switched to the first exhaust mode, the second exhaust mode, the third exhaust mode and the fourth exhaust mode in sequence until the exhaust interval satisfies the exhaust purge time .

[0071] Specifically, it is judged whether the hydrogen supply running time reaches the hydrogen supply pulsation exhaust interval ; if not, the hydrogen supply mode (I, II, III, IV) is continuously executed; if so, the exhaust mode (I, II, III, IV) is executed until the exhaust interval satisfies the exhaust purge time .

[0072] S4. When receiving a shutdown instruction, the running mode of the multi-stack fuel cell system is switched to the third exhaust mode, and the first fuel cell stack and the second fuel cell stack are respectively purged for 3 seconds, and then the system enters a shutdown state after all electromagnetic valves are closed.

[0073] Specifically, it is judged whether a shutdown instruction is received; if no shutdown instruction is received, the hydrogen supply mode of step S2 is continuously executed; if a shutdown instruction is received, the exhaust mode III is executed, each fuel cell stack is purged for 3 seconds to remove residual gas and water, and then all electromagnetic valves are closed, and the system enters a shutdown state.

[0074] In this embodiment, when the inlet hydrogen pressure, the outlet hydrogen pressure and the stack voltage of the first fuel cell stack or the second fuel cell stack are all lower than the normal value, the stack is determined as an abnormal stack, the abnormal stack is immediately controlled to stop working, and the independent running mode (hydrogen supply mode V or VI, exhaust mode V or VI) is started.

[0075] In this embodiment, under high load conditions (>80% rated power), the multi-stack fuel cell system is controlled to run in hydrogen mode I and II to meet , and series mode is preferred to improve hydrogen supply efficiency. Under low load conditions (<30% rated power), the multi-stack fuel cell system is controlled to run in hydrogen mode III and IV to meet , and parallel mode is preferred to improve the service life of the fuel cell.

[0076] Figure 7 and Figure 8 respectively show the two operation modes of the above multi-stack fuel cell system.

[0077] As shown in Figure 7 , the hydrogen supply pulsation exhaust interval is , and the operation mode of the multi-stack fuel cell system does not change within the hydrogen supply pulsation exhaust interval , the number of changes is , that is, only one mode is run within each hydrogen supply pulsation exhaust interval. When the running time reaches , the corresponding hydrogen exhaust mode is executed, and the hydrogen supply operation mode is switched in the next cycle . As shown in Figure 7 , hydrogen supply mode I is executed within the first hydrogen supply pulsation exhaust interval , when the running time reaches , hydrogen exhaust mode I is started, when the hydrogen exhaust purge time reaches , hydrogen supply mode II is started, and so on.

[0078] As shown in Figure 8 , the operation mode of the multi-stack fuel cell system changes once within the hydrogen supply pulsation exhaust interval , the number of changes is , that is, two modes are run within each hydrogen supply pulsation exhaust interval. Hydrogen supply mode I and hydrogen supply mode II are executed within the first hydrogen supply pulsation exhaust interval , when the running time reaches , hydrogen exhaust mode II corresponding to hydrogen supply mode II is started. Hydrogen supply mode III and hydrogen supply mode IV are executed within the second hydrogen supply pulsation exhaust interval , when the running time reaches , hydrogen exhaust mode IV corresponding to hydrogen supply mode IV is started. It is worth noting that the running order needs to be exchanged within the third hydrogen supply pulsation exhaust interval , hydrogen supply mode II is executed first, hydrogen supply mode I is executed second, hydrogen exhaust mode I is executed after the running time reaches , and the alternate hydrogen exhaust ensures that each hydrogen exhaust mode is run.

[0079] Compared with the prior art, the present application has the following advantages.

[0080] 1. Multiple operation modes for flexible adaptation to complex working conditions: The system supports 12 operation modes (6 hydrogen supply modes and 6 hydrogen exhaust modes), which dynamically switch between series, parallel and independent hydrogen supply strategies to fully combine the advantages of different structures. The series mode concentrates gas supply at high loads to improve hydrogen supply efficiency; the parallel mode disperses gas flow at low loads to reduce the burden on individual stacks; and the independent mode isolates abnormal stacks for processing, ensuring the overall operation of the system. This flexible switching mechanism can be dynamically adjusted according to real-time working conditions, taking into account power demand and stack life, significantly improving the adaptability of the system in diversified scenarios (such as vehicle start-stop and distributed power generation load fluctuations).

[0081] 2. Hydrogen pressure pulsation enhances mass transfer and suppresses water flooding and impurity accumulation: A periodic pulsating hydrogen exhaust strategy is adopted to form controllable pressure pulsations in the anode flow field. This active disturbance breaks down local stagnant zones, accelerates hydrogen diffusion and water removal, effectively alleviating water flooding problems; at the same time, it removes accumulated inert gases such as nitrogen through pulsating purging, maintaining anode reaction activity. Compared to traditional fixed parameter purging, dynamic pulsating control can more accurately balance mass transfer efficiency and hydrogen consumption, prolonging the service life of the stack.

[0082] 3. Intelligent fault-tolerant design to improve system redundancy and reliability: By monitoring the inlet hydrogen pressure, outlet hydrogen pressure and stack voltage of each stack in real time, single-stack abnormalities (such as leaks and performance degradation) can be quickly identified. Once an anomaly is detected, the independent hydrogen supply mode is triggered to isolate the faulty stack, and the remaining stacks continue to work cooperatively to ensure system output continuity. This "sick running" capability significantly reduces the risk of system downtime due to single-stack failure, making it particularly suitable for vehicle and distributed power generation scenarios where reliability is extremely important.

[0083] 4. Load adaptive control to balance efficiency and life: Based on load conditions, the operation strategy is dynamically adjusted: at high loads, the series mode is preferred to improve power generation efficiency through high-pressure gas supply; at low loads, the parallel mode is switched to reduce stack current density and delay catalyst aging. Combined with pulsating parameter optimization, the system can balance performance while reducing hydrogen waste and stack wear at low loads, achieving economic and reliable balance in the entire working condition range.

[0084] The technical features of the above embodiments can be combined in any way. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not contradict, they should be considered within the scope of the present disclosure.

[0085] The principles and implementation manners of the present application are described herein by using specific examples, and the above examples are only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manners and application ranges will have changes. In conclusion, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A control method of an anode-supplied variable-configuration multi-stack fuel cell system, characterized by, The control method is applied to an anode hydrogen supply variable configuration multi-stack fuel cell system, and operation modes of the multi-stack fuel cell system include a hydrogen series operation mode, a hydrogen parallel operation mode and an independent operation mode; the hydrogen series operation mode includes a first hydrogen supply mode, a first hydrogen discharge mode, a second hydrogen supply mode and a second hydrogen discharge mode; the hydrogen parallel operation mode includes a third hydrogen supply mode, a third hydrogen discharge mode, a fourth hydrogen supply mode and a fourth hydrogen discharge mode; the independent operation mode includes a fifth hydrogen supply mode, a fifth hydrogen discharge mode, a sixth hydrogen supply mode and a sixth hydrogen discharge mode; the control method comprises: setting a hydrogen supply pulse discharge interval, a hydrogen discharge purge time, a number of changes of operation modes in each hydrogen discharge cycle and operation time of each hydrogen supply mode in the hydrogen series and parallel operation mode; sequentially switching the operation modes of the multi-stack fuel cell system to the first hydrogen supply mode, the second hydrogen supply mode, the third hydrogen supply mode and the fourth hydrogen supply mode until the number of changes is reached; when the operation time reaches the hydrogen supply pulse discharge interval, detecting a current hydrogen supply operation state, switching to a hydrogen discharge mode corresponding to the current hydrogen supply mode until the operation time of the corresponding hydrogen discharge mode meets the hydrogen discharge purge time; when a shutdown instruction is received, switching the operation mode of the multi-stack fuel cell system to the third hydrogen discharge mode, purging the first fuel cell stack and the second fuel cell stack for 3 seconds respectively, then closing all electromagnetic valves, and the multi-stack fuel cell system enters a shutdown state; the hydrogen series operation mode includes: the first hydrogen supply mode, the first hydrogen discharge mode, the second hydrogen supply mode and the second hydrogen discharge mode; in the first hydrogen supply mode, the first hydrogen inlet electromagnetic valve and the communication electromagnetic valve are opened, and the remaining electromagnetic valves are all closed; in the first hydrogen discharge mode, the first hydrogen inlet electromagnetic valve, the communication electromagnetic valve and the fourth hydrogen discharge electromagnetic valve are opened, and the remaining electromagnetic valves are all closed; in the second hydrogen supply mode, the second hydrogen inlet electromagnetic valve and the communication electromagnetic valve are opened, and the remaining electromagnetic valves are all closed; in the second hydrogen discharge mode, the second hydrogen inlet electromagnetic valve, the communication electromagnetic valve and the first hydrogen discharge electromagnetic valve are opened, and the remaining electromagnetic valves are all closed; the hydrogen parallel operation mode includes: the third hydrogen supply mode, the third hydrogen discharge mode, the fourth hydrogen supply mode and the fourth hydrogen discharge mode; in the third hydrogen supply mode, the first hydrogen inlet electromagnetic valve and the second hydrogen inlet electromagnetic valve are opened, and the remaining electromagnetic valves are all closed; in the third hydrogen discharge mode, the first hydrogen inlet electromagnetic valve, the second hydrogen inlet electromagnetic valve, the second hydrogen discharge electromagnetic valve and the third hydrogen discharge electromagnetic valve are opened, and the remaining electromagnetic valves are all closed; in the fourth hydrogen supply mode, the first hydrogen inlet electromagnetic valve, the second hydrogen inlet electromagnetic valve and the communication electromagnetic valve are opened, and the remaining electromagnetic valves are all closed; in the fourth hydrogen discharge mode, the first hydrogen inlet electromagnetic valve, the second hydrogen inlet electromagnetic valve, the communication electromagnetic valve and the third hydrogen discharge electromagnetic valve are opened, and the remaining electromagnetic valves are all closed; the independent operation mode includes: the fifth hydrogen supply mode, the fifth hydrogen discharge mode, the sixth hydrogen supply mode and the sixth hydrogen discharge mode; in the fifth hydrogen supply mode, the first hydrogen inlet electromagnetic valve is opened, and the remaining electromagnetic valves are all closed; in the fifth hydrogen discharge mode, the first hydrogen inlet electromagnetic valve and the second hydrogen discharge electromagnetic valve are opened, and the remaining electromagnetic valves are all closed; in the sixth hydrogen supply mode, the first hydrogen inlet electromagnetic valve and the second hydrogen inlet electromagnetic valve are opened, and the remaining electromagnetic valves are all closed; in the sixth hydrogen discharge mode, the first hydrogen inlet electromagnetic valve, the second hydrogen inlet electromagnetic valve, the second hydrogen discharge electromagnetic valve and the third hydrogen discharge electromagnetic valve are opened, and the remaining electromagnetic valves are all closed. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ In the sixth hydrogen supply mode, the second hydrogen inlet electromagnetic valve is opened, and the rest of the electromagnetic valves are all closed. In the sixth hydrogen discharge mode, the second hydrogen inlet electromagnetic valve and the third hydrogen discharge electromagnetic valve are opened, and the rest of the electromagnetic valves are all closed.

2. The control method of a variable-configuration multi-stack fuel cell system of claim 1, characterized by, When the inlet and outlet hydrogen pressures and the voltage of the first fuel cell stack or the second fuel cell stack are both lower than the normal values, the first fuel cell stack or the second fuel cell stack is determined as an abnormal stack, the abnormal stack is controlled to stop running, and the independent running mode is started.

3. The control method of a variable-configuration multi-stack fuel cell system of claim 1, wherein In the high load working condition, the running mode of the multi-stack fuel cell system is controlled to be the hydrogen series running mode; in the low load working condition, the running mode of the multi-stack fuel cell system is controlled to be the hydrogen parallel running mode. The high load working condition is that the load power of the multi-stack fuel cell system is greater than 80% of the rated power when the multi-stack fuel cell system runs; the low load working condition is that the load power of the multi-stack fuel cell system is less than 30% of the rated power when the multi-stack fuel cell system runs.

4. An anode supply variable configuration multi-stack fuel cell system to which a control method according to any one of claims 1 to 3 is applied, characterized by It comprises: a hydrogen storage bottle, a first fuel cell stack, a second fuel cell stack, a hydrogen inlet electromagnetic valve group, a communication electromagnetic valve, a hydrogen discharge electromagnetic valve group, and a fuel cell control unit; The hydrogen inlet electromagnetic valve group is arranged on the connecting pipeline between the outlet of the hydrogen storage bottle and the first fuel cell stack, and on the connecting pipeline between the outlet of the hydrogen storage bottle and the second fuel cell stack; the first fuel cell stack and the second fuel cell stack are connected through the communication electromagnetic valve; the hydrogen discharge electromagnetic valve group is arranged at both ends of the first fuel cell stack and both ends of the second fuel cell stack; The hydrogen inlet electromagnetic valve group, the hydrogen discharge electromagnetic valve group, and the communication electromagnetic valve are connected with the fuel cell control unit; the fuel cell control unit is used for controlling the hydrogen inlet electromagnetic valve group, the hydrogen discharge electromagnetic valve group, and the communication electromagnetic valve to switch the running mode of the multi-stack fuel cell system; the running mode comprises a hydrogen series running mode, a hydrogen parallel running mode, and an independent running mode.

5. The anode-fed variable configuration multi-stack fuel cell system according to claim 4, wherein The hydrogen inlet electromagnetic valve group and the communication electromagnetic valve are normally open electromagnetic valves, and the hydrogen discharge electromagnetic valve group is a normally closed pulse exhaust valve.

6. The anode-fed variable configuration multi-stack fuel cell system according to claim 4, wherein The hydrogen inlet electromagnetic valve group comprises a first hydrogen inlet electromagnetic valve and a second hydrogen inlet electromagnetic valve; the first hydrogen inlet electromagnetic valve is arranged on the connecting pipeline between the outlet of the hydrogen storage bottle and the first fuel cell stack; the second hydrogen inlet electromagnetic valve is arranged on the connecting pipeline between the outlet of the hydrogen storage bottle and the second fuel cell stack; The hydrogen discharge electromagnetic valve group comprises a first hydrogen discharge electromagnetic valve, a second hydrogen discharge electromagnetic valve, a third hydrogen discharge electromagnetic valve, and a fourth hydrogen discharge electromagnetic valve; the first hydrogen discharge electromagnetic valve and the second hydrogen discharge electromagnetic valve are arranged at both ends of the first fuel cell stack; the third hydrogen discharge electromagnetic valve and the fourth hydrogen discharge electromagnetic valve are arranged at both ends of the second fuel cell stack.

7. The anode-fed variable configuration multi-stack fuel cell system according to claim 4, wherein The multi-stack fuel cell system further comprises a first hydrogen pressure sensor, a second hydrogen pressure sensor, a third hydrogen pressure sensor, a fourth hydrogen pressure sensor, a first voltage sensor, and a second voltage sensor; The first hydrogen pressure sensor and the second hydrogen pressure sensor are arranged at both ends of the first fuel cell stack and are used for collecting the inlet and outlet hydrogen pressures of the first fuel cell stack; The third hydrogen pressure sensor and the fourth hydrogen pressure sensor are arranged at both ends of the second fuel cell stack and are used for collecting the inlet and outlet hydrogen pressures of the second fuel cell stack; The third hydrogen pressure sensor and the fourth hydrogen pressure sensor are arranged at two ends of the second fuel cell stack, and are used to collect the inlet hydrogen pressure and the outlet hydrogen pressure of the second fuel cell stack; The first voltage sensor is arranged on the first fuel cell stack, and is used to collect the stack voltage of the first fuel cell stack; The second voltage sensor is arranged on the second fuel cell stack, and is used to collect the stack voltage of the second fuel cell stack; The fuel cell control unit is respectively connected with the first hydrogen pressure sensor, the second hydrogen pressure sensor, the third hydrogen pressure sensor, the fourth hydrogen pressure sensor, the first voltage sensor and the second voltage sensor, and is used to judge whether the first fuel cell stack and the second fuel cell stack are abnormal stacks according to the inlet hydrogen pressure, the outlet hydrogen pressure and the stack voltage of the first fuel cell stack and the second fuel cell stack, and control the abnormal stack to stop working and start the independent operation mode.

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