Fuel cell hydrogen tailing control method and apparatus

Abstract

This invention provides a method and apparatus for controlling hydrogen exhaust emissions from a fuel cell. The method includes: determining the covariance between a single-voltage dataset and a voltage difference dataset when the lowest single voltage of the fuel cell stack continuously falls below a preset alarm threshold; controlling the fuel cell to enter a hydrogen exhaust emission condition under a partial under-gas condition based on the covariance, the absolute voltage difference, and the fuel cell's hydrogen exhaust cycle, where a partial undergassing condition is determined at the stack electrodes; the absolute voltage difference is the absolute difference between the average single voltage and the lowest single voltage of the stack; constructing a model to characterize the hydrogen purging pressure loss of the fuel cell under determined fuel cell start-up and shutdown conditions, and compensating for the hydrogen purging pressure during the fuel cell start-up and shutdown phases based on the model; and controlling the opening of a drain valve after the fuel cell shutdown is completed. This invention achieves the goal of safe hydrogen purging and efficient exhaust emission in complex application scenarios of hydrogen fuel cell-powered ships.

Description

Technical Field

[0001] This invention relates to the field of hydrogen fuel cell powered ships, and specifically to a method and device for controlling hydrogen exhaust emissions from fuel cells. Background Technology

[0002] Hydrogen fuel cell power is suitable for various inland waterway, coastal, and ocean-going vessels, serving as both primary and auxiliary power. A proton exchange membrane fuel cell (PEMFC) is a power generation device that directly converts the chemical energy stored in fuel and oxidant into electrical energy. The internal hydrogen system of the fuel cell is a closed-loop system. Purge and exhaust processes remove small amounts of impurity gases, such as nitrogen and water produced during the fuel cell reaction.

[0003] Hydrogen fuel cell powered ships have enclosed and complex cabins, which place high demands on the safety of hydrogen-related areas and pipelines. The hydrogen exhaust system pipelines of fuel cells often have long distances, many bends, large diameter changes, and steep inclines. These factors are all unfavorable for the discharge of water from the hydrogen pipelines of fuel cells.

[0004] As fuel cells operate for longer periods, more and more water accumulates in the hydrogen exhaust pipe. During fuel cell startup, high back pressure at the anode prevents hydrogen from entering the stack channels for reaction, leading to startup failure. During operation, high-humidity hydrogen or liquid water recirculates to the anode inlet, causing low voltage or even shutdown due to anode under-gassing or flooding. However, existing methods cannot achieve safe purging and efficient exhaust of hydrogen in these complex applications of hydrogen-powered ships. Summary of the Invention

[0005] In view of this, it is necessary to provide a method and device for controlling hydrogen exhaust from fuel cells, so as to solve the technical problem that existing methods cannot achieve safe purging and efficient exhaust of hydrogen in complex application scenarios of hydrogen fuel-powered ships.

[0006] To address the aforementioned problems, in a first aspect, the present invention provides a method for controlling hydrogen exhaust emissions from a fuel cell, comprising: If the lowest single voltage of the fuel cell stack falls below a preset alarm threshold at least twice consecutively within a target time period, the covariance between the single voltage dataset and the voltage difference dataset is determined; the voltage difference dataset is the dataset of the difference between the single voltage of the fuel cell stack and the average single voltage of the fuel cell stack. Based on the covariance, absolute voltage difference, and hydrogen tail gas cycle of the fuel cell, when the local undergassing of the stack electrodes is determined, the fuel cell is controlled to enter the hydrogen tail gas under the local undergassing condition of the stack; the absolute voltage difference is the absolute difference between the average single voltage and the lowest single voltage of the stack. Under the determined operating conditions of fuel cell start-up and shutdown, a model is constructed to characterize the hydrogen purging pressure loss of the fuel cell, and the hydrogen purging pressure is compensated based on the model during the start-up and shutdown phases of the fuel cell. After the fuel cell is shut down, the drain valve on the fuel cell water pipeline is opened.

[0007] In one possible implementation, the start-up and shutdown conditions of the fuel cell are determined, including: The input character set of the finite state machine corresponding to the fuel cell is determined, and the state transition function of the finite state machine is determined based on the input character set; the input character set includes: fuel cell control commands, fuel cell operating modes, and fuel cell operating states; Based on the finite non-empty set of states of the finite state machine and the state transition function, determine whether the hydrogen purging and exhaust conditions of the fuel cell are the conditions for fuel cell start-up and shutdown.

[0008] In one possible implementation, determining the covariance between the stack single voltage dataset and the voltage difference dataset includes: Construct a single voltage dataset for the entire stack, containing the single voltage of all sections, and update the single voltage dataset using a sliding window method. Construct a voltage difference dataset containing the difference between the single voltage and the average single voltage for all sections of the fuel cell stack, and update the voltage difference dataset using a sliding window method; Determine the covariance between the single voltage dataset of the fuel cell stack and the voltage difference dataset.

[0009] In one possible implementation, determining local undergassing of the stack electrodes based on the covariance, absolute voltage difference, and hydrogen tail gas cycle of the fuel cell includes: The absolute voltage difference is fitted using the least squares method to obtain the first relationship; The hydrogen tail emission period was fitted using the least squares method to obtain the second relationship; If the ratio of the derivative of the first relation to the derivative of the second relation is greater than 0, and the mean of the covariance decreases, then a local gas shortage at the anode of the fuel cell stack is determined.

[0010] In one possible implementation, determining the local undergassing of the stack electrodes based on the covariance, absolute voltage difference, and hydrogen tail gas cycle of the fuel cell further includes: If the ratio of the derivative of the first relation to the derivative of the second relation is less than or equal to 0, and the mean of the covariance increases, then a local undergassing of the cathode in the fuel cell stack is determined.

[0011] In one possible implementation, a model is constructed to characterize the hydrogen purge pressure loss in the fuel cell, including: Based on the hydrogen purging pressure and pressure loss of the fuel cell, the effective hydrogen purging pressure of the fuel cell is obtained; The pressure loss includes pressure loss caused by the change in diameter of the external hydrogen exhaust pipe of the fuel cell, pressure loss caused by the incline of the external hydrogen exhaust pipe of the fuel cell, pressure loss caused by the installation of a water tank in the external hydrogen exhaust pipe of the fuel cell, pressure loss along the friction of the external hydrogen exhaust pipe of the fuel cell, and pressure loss caused by the installation of a valve in the external hydrogen exhaust pipe of the fuel cell.

[0012] In one possible implementation, the fuel cell hydrogen exhaust control method further includes: A power consumption dataset containing the real-time power consumption of the hydrogen pump is constructed, and the power consumption dataset is low-pass filtered to obtain the basic quantity of the hydrogen pump power consumption. Real-time monitoring of the water separation data of the fuel cell steam-water separator; after the stable water separation time corresponding to the water separation data exceeds the set time, the tail exhaust cycle correction amount is determined based on the baseline amount of hydrogen pump power consumption and the theoretical power consumption of hydrogen pump. The hydrogen tail-off cycle of the fuel cell is corrected based on the tail-off cycle correction amount.

[0013] In one possible implementation, the tailrace cycle correction is determined based on the baseline power consumption of the hydrogen pump and the theoretical power consumption of the hydrogen pump, including: When the baseline power consumption of the hydrogen pump is less than n times the theoretical power consumption of the hydrogen pump, the tail exhaust cycle correction is determined to be the first value; 0 <n<1; When the baseline power consumption of the hydrogen pump is less than or equal to m times the theoretical power consumption of the hydrogen pump and greater than or equal to n times the theoretical power consumption of the hydrogen pump, the tail exhaust cycle correction amount is determined to be the second value; m>1; When the baseline power consumption of the hydrogen pump is greater than m times the theoretical power consumption of the hydrogen pump, the tail exhaust cycle correction amount is determined to be the third value. Wherein, the first value is less than the second value, and the second value is less than the third value.

[0014] In one possible implementation, the fuel cell hydrogen exhaust control method further includes: Monitor the relative vacuum level of the hydrogen pipeline inside the fuel cell. If the relative vacuum level is less than 0, stop the fuel cell hydrogen exhaust control program.

[0015] In a second aspect, the present invention also provides a fuel cell hydrogen exhaust control device, comprising: The covariance determination module is used to determine the covariance between the stack single voltage dataset and the voltage difference dataset when the lowest single voltage of the fuel cell stack is lower than a preset alarm threshold at least twice consecutively within a target time period; the voltage difference dataset is the dataset of the difference between the stack single voltage and the stack average single voltage. The first tail exhaust control module is used to control the fuel cell to enter the hydrogen tail exhaust under the local under-gas condition of the fuel cell stack when the stack electrode is locally under-gas based on the covariance, the absolute voltage difference and the hydrogen tail exhaust cycle of the fuel cell; the absolute voltage difference is the absolute difference between the average single voltage and the lowest single voltage of the fuel cell stack. The second tailpipe control module is used to construct a model to characterize the hydrogen purging pressure loss of the fuel cell under the determined operating conditions of fuel cell start-up and shutdown, and to compensate for the hydrogen purging pressure during the start-up and shutdown phases of the fuel cell based on the model. After the fuel cell is shut down, it controls the opening of the drain valve on the fuel cell water pipeline.

[0016] The beneficial effects of the above implementation are as follows: The fuel cell hydrogen exhaust control method and device provided by this invention initiate exhaust control when the lowest single voltage of the fuel cell stack falls below a preset alarm threshold at least twice consecutively within a target time period. Compared to the traditional hydrogen pulse exhaust method, the fuel cell single voltage designed in this invention can be quickly adjusted when it deviates from the normal range, while remaining unadjusted within the normal range, thus reducing control difficulty. This invention, by calculating the covariance value, can analyze the recovery of the fuel cell stack single voltage after changes in the hydrogen exhaust strategy, achieving the identification of local undergassing conditions at the fuel cell anode. It formulates fuel cell hydrogen purging and exhaust strategies according to different fuel cell operating conditions, i.e., determining whether the current operating condition is a local undergassing condition at the stack electrodes or a fuel cell start-up / shutdown condition, and adopting different purging and exhaust strategies accordingly. Under fuel cell start-up / shutdown conditions, a method for compensating for exhaust / purging pressure loss caused by complex hydrogen exhaust pipelines is proposed, making exhaust more efficient under these conditions. This invention adopts different purging and tail exhaust strategies for different operating conditions, so as to achieve safe purging and efficient tail exhaust of hydrogen in complex application scenarios of hydrogen fuel-powered ships. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1A flowchart of an embodiment of the fuel cell hydrogen exhaust control method provided by the present invention; Figure 2 A schematic diagram of a hydrogen purging and exhaust control system for a hydrogen fuel cell in a hydrogen-powered ship, provided by the present invention. Figure 3 A flowchart of another embodiment of the fuel cell hydrogen exhaust control method provided by the present invention; Figure 4 A flowchart of the method for identifying local undergassing conditions in a fuel cell stack provided by the present invention; Figure 5 A flowchart of the fuel cell hydrogen purging pressure compensation method provided by the present invention; Figure 6 A flowchart of the tail exhaust control method based on fuel cell hydrogen pump power consumption provided by the present invention; Figure 7 A flowchart of the fuel cell hydrogen pipeline vacuum monitoring anomaly and tail exhaust control safety protection method provided by the present invention; Figure 8 This is a schematic diagram of an example of single-voltage recovery of a fuel cell implemented using the control method provided by the present invention; Figure 9 A schematic block diagram of an embodiment of the fuel cell hydrogen exhaust control device provided by the present invention; Figure 10 A schematic diagram of an embodiment of the electronic device provided by the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0020] In the description of the embodiments of this application, unless otherwise stated, "a plurality of" means two or more.

[0021] In this embodiment of the invention, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, apparatus, product or device that includes a series of steps or modules is not necessarily limited to those steps or modules that are explicitly listed, but may include other steps or modules that are not explicitly listed or that are inherent to such process, method, product or device.

[0022] The naming or numbering of steps in the embodiments of the present invention does not mean that the steps in the method flow must be executed in the time / logical order indicated by the naming or numbering. The execution order of the named or numbered process steps can be changed according to the technical purpose to be achieved, as long as the same or similar technical effect can be achieved.

[0023] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0024] This invention relates to hydrogen exhaust from fuel cells on ships. The method provided by this invention can be executed based on an application on a terminal or server. The terminal can be a mobile phone, tablet computer, or a smart terminal on the ship, and the server can be an edge server or a cloud server.

[0025] like Figure 1 As shown, the present invention provides a method for controlling hydrogen exhaust emissions from a fuel cell, comprising: S101. If the lowest single voltage of the fuel cell stack is lower than the preset alarm threshold at least twice consecutively within the target time period, determine the covariance between the single voltage dataset and the voltage difference dataset; the voltage difference dataset is the dataset of the difference between the single voltage of the fuel cell stack and the average single voltage of the fuel cell stack.

[0026] Understandably, during continuous operation of a fuel cell, if the lowest single voltage of the stack is detected to be lower than the alarm threshold at least twice consecutively within the target time period, it indicates that a small amount of impurity gases, such as nitrogen and water produced during the reaction of the fuel cell stack need to be discharged. This initiates the hydrogen tail emission control process for the local undergassing condition of the fuel cell stack, and the covariance between the single voltage dataset and the voltage difference dataset of the stack is calculated.

[0027] When the lowest single voltage of the fuel cell stack is continuously higher than the alarm threshold, the fuel cell enters the hydrogen exhaust control process under normal operating conditions.

[0028] It should be noted that the determination of the above-mentioned fault thresholds, alarm thresholds and other judgment conditions needs to take into account the influence of the fuel cell stack operating temperature.

[0029] S102. Based on the covariance, absolute voltage difference, and hydrogen tailing cycle of the fuel cell, when the stack electrode is found to be partially under-gas, the fuel cell is controlled to enter the hydrogen tailing condition under the partial under-gas condition of the stack; the absolute voltage difference is the absolute difference between the average single voltage and the lowest single voltage of the stack.

[0030] It is understandable that the fuel cell stack experiences partial undergassing conditions, including partial undergassing conditions at the anode and cathode. Both the single-voltage dataset and the voltage difference dataset are updated in real time, and there are multiple corresponding covariances. Based on the changes in the mean of these covariances and the changes in the absolute voltage difference relative to the hydrogen exhaust cycle of the fuel cell, it can be determined whether the fuel cell has entered a partial undergassing condition.

[0031] S103. Under the determined operating conditions of fuel cell start-up and shutdown in the marine application scenario, a model is constructed to characterize the hydrogen purging pressure loss of the fuel cell, and the hydrogen purging pressure is compensated based on the model during the start-up and shutdown phases of the fuel cell. After the fuel cell is shut down, the drain valve on the fuel cell water pipeline is opened to drain the water in the fuel cell water tank.

[0032] Understandably, the schematic diagram of the fuel cell hydrogen exhaust control system is as follows: Figure 2 As shown, when controlling the hydrogen purging of the fuel cell, it is necessary to adjust the purging pressure. However, there is a gap between the set purging pressure and the actual effective purging pressure because of pressure loss. Therefore, it is necessary to construct a loss model to compensate for the purging pressure, especially to compensate for the hydrogen purging pressure during the fuel cell start-up and shutdown phases, as the pressure loss is relatively large during these phases.

[0033] In some embodiments, determining the start-up and shutdown conditions of fuel cells in marine application scenarios includes: The input character set of the finite state machine corresponding to the fuel cell is determined, and the state transition function of the finite state machine is determined based on the input character set; the input character set includes: fuel cell control commands, fuel cell operating modes, and fuel cell operating states; Based on the finite non-empty set of states of the finite state machine and the state transition function, determine whether the hydrogen purging and exhaust conditions of the fuel cell are the start-up and shutdown conditions of the fuel cell in a marine application scenario.

[0034] Understandably, the fuel cell hydrogen purging and exhaust condition analysis method based on finite state machine theory is as follows: The input character set of this finite state machine is Σ={Cmd, Mode, Stepflag}; in: Cmd—Fuel cell control command; Mode—Fuel cell operating mode; Stepflag—Fuel cell operating status.

[0035] The finite non-empty state set S of the finite state machine is used to formulate the hydrogen purging and exhaust conditions of the fuel cell in combination with the working conditions of the fuel cell. The initial state of the finite state machine is s0; The state transition function δ of the finite state machine can be expressed by the following formula: δ=δ(Cmd,Mode,Stepflag) The final state set F of the finite state machine includes normal final states and fault-prone final states.

[0036] In some embodiments, determining the covariance between the stack single voltage dataset and the voltage difference dataset includes: Construct a single voltage dataset for the entire stack, containing the single voltage of all sections, and update the single voltage dataset using a sliding window method. Construct a voltage difference dataset containing the difference between the single voltage and the average single voltage for all sections of the fuel cell stack, and update the voltage difference dataset using a sliding window method; Determine the covariance between the single voltage dataset of the fuel cell stack and the voltage difference dataset.

[0037] It is understandable that a capacity is set to... N 1. Real-time dataset V, single voltage of all sections of the fuel cell stack. V n is filled into the real-time dataset, and the fully filled real-time dataset is continuously updated in the form of a sliding window to obtain the data filled into the updated real-time dataset.

[0038] Set a capacity of N The real-time dataset E is filled with the difference between the single voltage and the average single voltage of all sections of the fuel cell stack. The real-time dataset is continuously updated in the form of a sliding window to obtain the data filled in the updated real-time dataset. The covariance of datasets V and E is calculated using the following formula. ;

[0039]

[0040]

[0041] Real-time recording of the above N 2 covariances Input the data into dataset O and calculate its average. ;

[0042] In some embodiments, determining local undergassing of the stack electrodes based on the covariance, absolute voltage difference, and hydrogen tail gas cycle of the fuel cell includes: The absolute voltage difference is fitted using the least squares method to obtain the first relationship; The hydrogen tail emission period was fitted using the least squares method to obtain the second relationship; If the ratio of the derivative of the first relation to the derivative of the second relation is greater than 0, and the mean of the covariance decreases, then a local gas shortage at the anode of the fuel cell stack is determined.

[0043] It is understandable that a capacity is set to... N The real-time dataset U is filled with the absolute difference between the average single voltage and the lowest single voltage of the fuel cell stack, and the real-time dataset is continuously updated in the form of a sliding window to obtain the data filled in the updated real-time dataset. Set a capacity of N 3 Real-time dataset T Tail exhaust cycle T n The real-time dataset is populated sequentially, and the fully populated real-time dataset is continuously updated using a sliding window to obtain the populated data in the updated real-time dataset. The least squares method was used to fit the result. U and T Relationship, U = aT n + bT n-1 +…+ c By differentiating this relation, we can obtain d. U / d T = a n T n-1 + b ( n -1) T n-2 +…; When d U / d T When >0, simultaneously appear As the fuel cell controller shrinks, it enters the hydrogen tail exhaust under the partial undergassing condition of the stack anode.

[0044] In some embodiments, determining local undergassing of the stack electrodes based on the covariance, absolute voltage difference, and hydrogen tail gas cycle of the fuel cell further includes: If the ratio of the derivative of the first relation to the derivative of the second relation is less than or equal to 0, and the mean of the covariance increases, then a local undergassing of the cathode in the fuel cell stack is determined.

[0045] It is understandable that when d U / d T When ≤0, both occur simultaneously As the pressure increases, the fuel cell controller enters the hydrogen tail gas control program under the condition of insufficient gas at the stack cathode.

[0046] In some embodiments, a model is constructed to characterize the hydrogen purge pressure loss in a fuel cell, including: Based on the hydrogen purging pressure and pressure loss of the fuel cell, the effective hydrogen purging pressure of the fuel cell is obtained; The pressure loss includes pressure loss caused by the change in diameter of the external hydrogen exhaust pipe of the fuel cell, pressure loss caused by the incline of the external hydrogen exhaust pipe of the fuel cell, pressure loss caused by the installation of a water tank in the external hydrogen exhaust pipe of the fuel cell, pressure loss along the friction of the external hydrogen exhaust pipe of the fuel cell, and pressure loss caused by the installation of a valve in the external hydrogen exhaust pipe of the fuel cell.

[0047] Understandably, a hydrogen purge pressure loss model for fuel cells is constructed as follows: P' = P - P RD - P CLM – P WB - P FRC - P VLV in: P' — Effective hydrogen purging pressure for fuel cells; P—Hydrogen purging pressure for fuel cells; P RD — Pressure loss caused by the change in diameter of the external hydrogen exhaust pipe of the fuel cell; P CLM — Pressure loss caused by the uphill ramp of the external hydrogen exhaust pipe of the fuel cell; P WB — Pressure loss caused by installing a water tank in the external hydrogen exhaust pipe of the fuel cell; P FRC — Pressure loss along the external hydrogen exhaust pipe of the fuel cell; P VLV — Pressure loss caused by valves installed in the external hydrogen exhaust pipe of the fuel cell; In some embodiments, the fuel cell hydrogen exhaust control method further includes: A power consumption dataset containing the real-time power consumption of the hydrogen pump is constructed, and the power consumption dataset is low-pass filtered to obtain the basic quantity of the hydrogen pump power consumption. Real-time monitoring of the water separation data of the fuel cell steam-water separator; after the stable water separation time corresponding to the water separation data exceeds the set time, the tail exhaust cycle correction amount is determined based on the baseline amount of hydrogen pump power consumption and the theoretical power consumption of hydrogen pump. The hydrogen tail-off cycle of the fuel cell is corrected based on the tail-off cycle correction amount.

[0048] It is understandable that a capacity is set to... N Real-time dataset of 3, real-time power consumption P of hydrogen pump pump The data is saved to the dataset in real time and updated in real time. The data in the real-time dataset is then low-pass filtered to obtain the low-frequency component P of the hydrogen pump power consumption. act This serves as the baseline for the power consumption of the hydrogen pump; Real-time monitoring of water separation data from the fuel cell gas-water separator; when the stable water separation time exceeds the set time tsplit, the tail exhaust cycle correction amount is determined based on the baseline amount of hydrogen pump power consumption and the theoretical power consumption of the hydrogen pump.

[0049] In some embodiments, the tailrace cycle correction is determined based on the baseline power consumption of the hydrogen pump and the theoretical power consumption of the hydrogen pump, including: When the baseline power consumption of the hydrogen pump is less than n times the theoretical power consumption of the hydrogen pump, the tail exhaust cycle correction is determined to be the first value; 0 <n<1; When the baseline power consumption of the hydrogen pump is less than or equal to m times the theoretical power consumption of the hydrogen pump and greater than or equal to n times the theoretical power consumption of the hydrogen pump, the tail exhaust cycle correction amount is determined to be the second value; m>1; When the baseline power consumption of the hydrogen pump is greater than m times the theoretical power consumption of the hydrogen pump, the tail exhaust cycle correction amount is determined to be the third value. Wherein, the first value is less than the second value, and the second value is less than the third value.

[0050] It is understandable that the low-frequency component (basic quantity) P of the hydrogen pump power consumption is compared. act The theoretical power consumption P of the hydrogen pump the The value is defined as the periodic correction amount as follows: T=

[0051] in: —Basic duration of hydrogen exhaust cycle —Low power consumption —High power consumption — Hydrogen exhaust cycle reduction factor — Hydrogen exhaust period increase factor In some embodiments, the fuel cell hydrogen exhaust control method further includes: Monitor the relative vacuum level of the hydrogen pipeline inside the fuel cell. If the relative vacuum level is less than 0, stop the fuel cell hydrogen exhaust control program.

[0052] It is understandable that monitoring the relative vacuum P of the hydrogen pipeline inside the fuel cell is important. neg If P neg If the value is less than 0, it indicates an abnormal relative vacuum level, and cleaning and tail discharge are not required.

[0053] In some embodiments, the present invention provides a method for hydrogen purging and exhaust control of a fuel cell in a hydrogen-powered ship, such as... Figure 3 As shown, it includes: S301, first perform working condition identification; S302, enter the corresponding control process according to different working conditions. Specifically, it includes: 1. A method for analyzing hydrogen exhaust conditions in fuel cells based on finite state machine theory, as detailed below; Step 1.1: The input character set Σ={Cmd, Mode, Stepflag} of this finite state machine; Wherein, Cmd is the fuel cell control command, [2,3,5]; Mode—Fuel cell operating mode, [1,2,3,4]; Stepflag—Fuel cell operating status, [1,3,4,5,6,7,8].

[0054] Step 1.2: The finite non-empty set of states of the finite state machine is S = {Sstandby, Sstart, Srun, Sstop1, Sstop2, Sfault, Slock}; in: Sstandby — Hydrogen exhaust condition during fuel cell standby; Sstart—Hydrogen purging condition during fuel cell startup; Srun—Hydrogen exhaust condition during fuel cell operation; Sstop1—Hydrogen purging condition 1 during fuel cell shutdown; Sstop2—Hydrogen purging condition 2 during fuel cell shutdown (including external pipeline water purging); Sfault—Hydrogen purging condition during fuel cell failure; Slock—Hydrogen purging condition when the fuel cell is locked.

[0055] Step 1.3: The initial state of the finite state machine is s0 = Sstandby; Step 1.4: The state transition function δ of this finite state machine can be expressed by the following formula: δ=δ(Cmd,Mode,Stepflag) Where Cmd=[2,3,5],Mode=[1,2,3,4],Stepflag=[1,3,4,5,6,7,8].

[0056] Step 1.5: The final state set of this finite state machine is F = {Sstandby, Slock}.

[0057] 2. A hydrogen tail gas control method for local under-gas conditions in fuel cell stacks based on single voltage, such as... Figure 4 As shown, the details are as follows: S401: During continuous operation of the fuel cell, when the lowest single voltage of the stack is continuously lower than the alarm threshold, the fuel cell stack partial undergassing condition hydrogen exhaust control process is entered. S402: Calculate the covariance of the stack single voltage dataset, the single voltage dataset, and the average single voltage difference dataset; Set up a real-time dataset V with a capacity of 340. Fill the real-time dataset with the single voltage Vn of all sections of the fuel cell stack. Then, use a sliding window to continuously update the fully filled real-time dataset to obtain the data filled in the updated real-time dataset. Set up a real-time dataset E with a capacity of 340. Fill the real-time dataset with the difference between the single voltage and the average single voltage of all sections of the fuel cell stack. Then, use a sliding window to continuously update the fully filled real-time dataset to obtain the data filled in the updated real-time dataset. The covariance of datasets V and E is calculated using the following formula. ;

[0058]

[0059]

[0060] Real-time recording of the above 400 covariances Input the data into dataset O and calculate its average. ;

[0061] S403: Calculate the correlation between the minimum single voltage recovery of the fuel cell stack and the hydrogen tail exhaust control method; Set up a real-time dataset with a capacity of 400. UThe absolute difference between the average single voltage and the lowest single voltage of the fuel cell stack is used to fill the real-time dataset in sequence, and the real-time dataset that has been fully filled is continuously updated in the form of a sliding window to obtain the data filled in the updated real-time dataset. Set up a real-time dataset with a capacity of 400. T Tail exhaust cycle T n The real-time dataset is populated sequentially, and the fully populated real-time dataset is continuously updated using a sliding window to obtain the populated data in the updated real-time dataset. The least squares method was used to fit the result. U and T Relationship, U = aT n + bT n-1 +…+ c By differentiating this relation, we can obtain d. U / d T = a n T n-1 + b ( n -1) T n-2 +…; S404: Based on the above results, implement different hydrogen exhaust control strategies, as follows: When d U / d T When >0, simultaneously appear As the fuel cell controller shrinks, it enters the hydrogen tail exhaust under the partial undergassing condition of the stack anode. When d U / d T When ≤0, both occur simultaneously As the pressure increases, the fuel cell controller enters the hydrogen tail gas control program under the condition of insufficient gas at the stack cathode.

[0062] S405: When the lowest single voltage of the fuel cell stack is continuously higher than the alarm threshold, the fuel cell enters the hydrogen exhaust control process under normal operating conditions. It should be noted that the determination of the above-mentioned fault thresholds, alarm thresholds and other judgment conditions should take into account the influence of the fuel cell stack operating temperature.

[0063] 3. Hydrogen purging control methods for fuel cell start-up and shutdown in hydrogen fuel cell-powered ship applications, such as... Figure 5 As shown, the details are as follows: S501: The hydrogen purge pressure loss model for a fuel cell is constructed as follows: P' = P - P RD - P CLM – P WB - P FRC - P VLV in: P' — Effective hydrogen purging pressure for fuel cells; P—Hydrogen purging pressure for fuel cells; P RD — Pressure loss caused by the change in diameter of the external hydrogen exhaust pipe of the fuel cell; P CLM — Pressure loss caused by the uphill ramp of the external hydrogen exhaust pipe of the fuel cell; P WB — Pressure loss caused by installing a water tank in the external hydrogen exhaust pipe of the fuel cell; P FRC — Pressure loss along the external hydrogen exhaust pipe of the fuel cell; P VLV — Pressure loss caused by valves installed in the external hydrogen exhaust pipe of the fuel cell; S502: Based on the hydrogen pressure loss model, the hydrogen purging pressure during the fuel cell start-up and shutdown phases is corrected. The pressure correction value is 12 kPa during the start-up phase and 13 kPa during the shutdown phase.

[0064] S503: After the fuel cell has stopped, control the drain valve to drain the water in the tank.

[0065] 4. A method for calculating the hydrogen exhaust control component based on hydrogen pump power consumption, such as... Figure 6 As shown, the details are as follows: S601: Set a real-time dataset P with a capacity of 4000, save the real-time power consumption Ppump of the hydrogen pump to the dataset in real time, and update the data in the dataset in real time. Perform low-pass filtering on the data filled in the real-time dataset to obtain the low-frequency component Pact of the hydrogen pump power consumption, which is used as the basis of the hydrogen pump power consumption. S602: Real-time monitoring of water separation data in the fuel cell steam-water separator; when the stable water separation time exceeds 100s; By comparing Pact with the theoretical power consumption Pthe of the hydrogen pump, the tailpipe cycle correction is defined as follows: T=

[0066] It should be noted that this tail-end cycle correction applies to the rated power output condition of the fuel cell, with an inlet water temperature of 65°C for the fuel cell stack.

[0067] Purging exhaust protection strategies based on the vacuum level of the internal hydrogen pipeline of fuel cells, such as Figure 7 As shown, the details are as follows: S701: Monitors the relative vacuum level (Pneg) of the hydrogen pipeline inside the fuel cell; S702: If Pneg < 0, it indicates an abnormal relative vacuum level, and the purging and tailpipe procedures should be stopped immediately.

[0068] Using the method provided in this embodiment, the single-voltage recovery of the fuel cell is as follows: Figure 8 As shown, the method provided in this embodiment can restore the single voltage of a fuel cell to a normal level.

[0069] The beneficial effects of this invention are: 1. This invention proposes a method for hydrogen purging and exhaust control in fuel cells. It formulates hydrogen purging and exhaust strategies based on different fuel cell operating conditions, proposes a method to compensate for exhaust / purging pressure loss caused by complex hydrogen exhaust pipelines in marine applications, and installs a water tank on the hydrogen exhaust pipeline, controlling the water distribution within the tank. It also proposes a method to assess the humidity of the hydrogen pipeline based on the real-time power consumption of the hydrogen pump (Balance of Plant, referring to all other components in a fuel cell system besides the fuel cell stack), adding one component to the control output. Finally, it proposes a purging and exhaust protection method based on vacuum monitoring of the internal hydrogen pipeline of the fuel cell, ensuring the safe and reliable operation of the fuel cell stack and hydrogen components. 2. Preferably, the present invention analyzes the recovery of the single voltage of the fuel cell stack after the hydrogen exhaust strategy changes by calculating the covariance value, thereby realizing the identification of the local under-gas condition of the fuel cell anode. Compared with the traditional hydrogen pulse exhaust method, the fuel cell single voltage designed in the present invention can be quickly regulated when it deviates from the normal range, while it is not regulated when it is within the normal range, thus reducing the difficulty of control.

[0070] like Figure 9 As shown, the present invention also provides a fuel cell hydrogen exhaust control device 900, comprising: The covariance determination module 901 is used to determine the covariance between the stack single voltage dataset and the voltage difference dataset when the lowest single voltage of the fuel cell stack is lower than a preset alarm threshold at least twice consecutively within a target time period; the voltage difference dataset is the dataset of the difference between the stack single voltage and the stack average single voltage. The first tail exhaust control module 902 is used to control the fuel cell to enter the hydrogen tail exhaust under the local under-gas condition of the fuel cell stack when the local undergas condition of the stack electrode is determined based on the covariance, the absolute voltage difference and the hydrogen tail exhaust cycle of the fuel cell; the absolute voltage difference is the absolute difference between the average single voltage and the lowest single voltage of the fuel cell stack. The second tailpipe control module 903 is used to construct a model to characterize the hydrogen purging pressure loss of the fuel cell under the working conditions of fuel cell start-up and shutdown in a defined marine application scenario, and to compensate for the hydrogen purging pressure during the start-up and shutdown phases of the fuel cell based on the model. After the fuel cell is shut down, it controls the opening of the drain valve on the fuel cell water pipeline.

[0071] The fuel cell hydrogen exhaust control device provided in the above embodiments can realize the technical solutions described in the above fuel cell hydrogen exhaust control method embodiments. The specific implementation principles of each module or unit can be found in the corresponding content in the above fuel cell hydrogen exhaust control method embodiments, which will not be repeated here.

[0072] like Figure 10 As shown, the present invention also provides an electronic device 1000. The electronic device 1000 includes a processor 1001, a memory 1002, and a display 1003. Figure 10 Only some components of the electronic device 1000 are shown, but it should be understood that it is not required to implement all the components shown, and more or fewer components may be implemented instead.

[0073] In some embodiments, memory 1002 may be an internal storage unit of electronic device 1000, such as a hard disk or memory of electronic device 1000. In other embodiments, memory 1002 may also be an external storage device of electronic device 1000, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc. equipped on electronic device 1000.

[0074] Furthermore, the memory 1002 may include both internal storage units of the electronic device 1000 and external storage devices. The memory 1002 is used to store application software and various types of data installed on the electronic device 1000.

[0075] In some embodiments, processor 1001 may be a central processing unit (CPU), microprocessor, or other data processing chip, used to run program code stored in memory 1002 or process data, such as the fuel cell hydrogen exhaust control method of the present invention.

[0076] In some embodiments, display 1003 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen. Display 1003 is used to display information from electronic device 1000 and to display a visual user interface. Components 1001-1003 of electronic device 1000 communicate with each other via a system bus.

[0077] In some embodiments of the present invention, when the processor 1001 executes the fuel cell hydrogen exhaust control program in the memory 1002, the following steps can be implemented: If the lowest single voltage of the fuel cell stack falls below a preset alarm threshold at least twice consecutively within a target time period, the covariance between the single voltage dataset and the voltage difference dataset is determined; the voltage difference dataset is the dataset of the difference between the single voltage of the fuel cell stack and the average single voltage of the fuel cell stack. Based on the covariance, absolute voltage difference, and hydrogen tail gas cycle of the fuel cell, when the local undergassing of the stack electrodes is determined, the fuel cell is controlled to enter the hydrogen tail gas under the local undergassing condition of the stack; the absolute voltage difference is the absolute difference between the average single voltage and the lowest single voltage of the stack. Under the defined operating conditions of fuel cell start-up and shutdown in a ship application scenario, a model is constructed to characterize the hydrogen purging pressure loss of the fuel cell. Based on the model, the hydrogen purging pressure is compensated during the start-up and shutdown phases of the fuel cell. After the fuel cell is shut down, the drain valve on the fuel cell water pipeline is opened.

[0078] It should be understood that when the processor 1001 executes the fuel cell hydrogen exhaust control program in the memory 1002, in addition to the functions mentioned above, it can also perform other functions, as detailed in the description of the corresponding method embodiments above.

[0079] Furthermore, the embodiments of the present invention do not specifically limit the type of the electronic device 1000 mentioned. The electronic device 1000 can be a mobile phone, tablet computer, personal digital assistant (PDA), wearable device, laptop computer, or other portable electronic device. Exemplary embodiments of portable electronic devices include, but are not limited to, portable electronic devices running iOS, Android, Microsoft, or other operating systems. The aforementioned portable electronic device can also be other portable electronic devices, such as a laptop computer with a touch-sensitive surface (e.g., a touch panel). It should also be understood that in some other embodiments of the present invention, the electronic device 1000 may not be a portable electronic device, but rather a desktop computer with a touch-sensitive surface (e.g., a touch panel).

[0080] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to perform the fuel cell hydrogen exhaust control method provided by the methods described above, the method comprising: If the lowest single voltage of the fuel cell stack falls below a preset alarm threshold at least twice consecutively within a target time period, the covariance between the single voltage dataset and the voltage difference dataset is determined; the voltage difference dataset is the dataset of the difference between the single voltage of the fuel cell stack and the average single voltage of the fuel cell stack. Based on the covariance, absolute voltage difference, and hydrogen tail gas cycle of the fuel cell, when the local undergassing of the stack electrodes is determined, the fuel cell is controlled to enter the hydrogen tail gas under the local undergassing condition of the stack; the absolute voltage difference is the absolute difference between the average single voltage and the lowest single voltage of the stack. Under the defined operating conditions of fuel cell start-up and shutdown in a ship application scenario, a model is constructed to characterize the hydrogen purging pressure loss of the fuel cell. Based on the model, the hydrogen purging pressure is compensated during the start-up and shutdown phases of the fuel cell. After the fuel cell is shut down, the drain valve on the fuel cell water pipeline is opened.

[0081] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0082] The fuel cell hydrogen exhaust control method and device provided by the present invention have been described in detail above. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for hydrogen tailing control of a fuel cell, characterized by, include: If the lowest single voltage of the fuel cell stack falls below a preset alarm threshold at least twice consecutively within a target time period, determine the covariance between the single voltage dataset and the voltage difference dataset. The voltage difference dataset is a dataset of the difference between the single voltage of the fuel cell stack and the average single voltage of the fuel cell stack. Based on the covariance, absolute voltage difference, and hydrogen tail gas cycle of the fuel cell, when the local undergassing of the stack electrodes is determined, the fuel cell is controlled to enter the hydrogen tail gas under the local undergassing condition of the stack; the absolute voltage difference is the absolute difference between the average single voltage and the lowest single voltage of the stack. Under the defined operating conditions of fuel cell start-up and shutdown in a ship application scenario, a model is constructed to characterize the hydrogen purging pressure loss of the fuel cell. Based on the model, the hydrogen purging pressure during the start-up and shutdown phases of the fuel cell is compensated. After the fuel cell is shut down, the drain valve on the fuel cell water pipeline is controlled to open. Based on the covariance, absolute voltage difference, and hydrogen tail gas cycle of the fuel cell, local undergassing of the stack electrodes is determined, including: The absolute voltage difference is fitted using the least squares method to obtain the first relationship; The hydrogen tail emission period was fitted using the least squares method to obtain the second relationship; If the ratio of the derivative of the first relation to the derivative of the second relation is greater than 0, and the mean of the covariance decreases, it is determined that the anode of the fuel cell stack is locally under-gasified. Based on the covariance, absolute voltage difference, and hydrogen tail gas cycle of the fuel cell, determining local undergassing of the stack electrodes further includes: If the ratio of the derivative of the first relation to the derivative of the second relation is less than or equal to 0, and the mean of the covariance increases, then a local undergassing of the cathode in the fuel cell stack is determined.

2. The fuel cell hydrogen exhaust control method according to claim 1, characterized in that, Determine the start-up and shutdown conditions of fuel cells in marine application scenarios, including: The input character set of the finite state machine corresponding to the fuel cell is determined, and the state transition function of the finite state machine is determined based on the input character set; the input character set includes: fuel cell control commands, fuel cell operating modes, and fuel cell operating states; Based on the finite non-empty set of states of the finite state machine and the state transition function, determine whether the hydrogen purging and exhaust conditions of the fuel cell are the start-up and shutdown conditions of the fuel cell in a marine application scenario.

3. The fuel cell hydrogen exhaust control method according to claim 1, characterized in that, Determine the covariance between the single-voltage dataset and the voltage difference dataset, including: Construct a single voltage dataset for the fuel cell stack containing the single voltage of all sections of the stack, and update the single voltage dataset for the fuel cell stack using a sliding window method; Construct a voltage difference dataset containing the difference between the single voltage and the average single voltage for all sections of the fuel cell stack, and update the voltage difference dataset using a sliding window method; Determine the covariance between the single voltage dataset of the fuel cell stack and the voltage difference dataset.

4. The fuel cell hydrogen exhaust control method according to claim 1, characterized in that, A model was constructed to characterize the hydrogen purge pressure loss in a fuel cell, including: Based on the hydrogen purging pressure and pressure loss of the fuel cell, the effective hydrogen purging pressure of the fuel cell is obtained; The pressure loss includes pressure loss caused by the change in diameter of the external hydrogen exhaust pipe of the fuel cell, pressure loss caused by the incline of the external hydrogen exhaust pipe of the fuel cell, pressure loss caused by the installation of a water tank in the external hydrogen exhaust pipe of the fuel cell, pressure loss along the friction of the external hydrogen exhaust pipe of the fuel cell, and pressure loss caused by the installation of a valve in the external hydrogen exhaust pipe of the fuel cell.

5. The fuel cell hydrogen exhaust control method according to claim 1, characterized in that, Also includes: A power consumption dataset containing the real-time power consumption of the hydrogen pump is constructed, and the power consumption dataset is low-pass filtered to obtain the basic quantity of the hydrogen pump power consumption. Real-time monitoring of the water separation data of the fuel cell steam-water separator; after the stable water separation time corresponding to the water separation data exceeds the set time, the tail exhaust cycle correction amount is determined based on the baseline amount of hydrogen pump power consumption and the theoretical power consumption of hydrogen pump. The hydrogen tail-off cycle of the fuel cell is corrected based on the tail-off cycle correction amount.

6. The fuel cell hydrogen exhaust control method according to claim 5, characterized in that, Based on the baseline power consumption of the hydrogen pump and the theoretical power consumption of the hydrogen pump, the tail exhaust cycle correction amount is determined, including: When the baseline power consumption of the hydrogen pump is less than n times the theoretical power consumption of the hydrogen pump, the tail exhaust cycle correction is determined to be the first value; 0 <n<1; When the baseline power consumption of the hydrogen pump is less than or equal to m times the theoretical power consumption of the hydrogen pump and greater than or equal to n times the theoretical power consumption of the hydrogen pump, the tail exhaust cycle correction amount is determined to be the second value; m>1; When the baseline power consumption of the hydrogen pump is greater than m times the theoretical power consumption of the hydrogen pump, the tail exhaust cycle correction amount is determined to be the third value. Wherein, the first value is less than the second value, and the second value is less than the third value.

7. The fuel cell hydrogen exhaust control method according to any one of claims 1-6, characterized in that, Also includes: Monitor the relative vacuum level of the hydrogen pipeline inside the fuel cell. If the relative vacuum level is less than 0, stop the fuel cell hydrogen exhaust control program.

8. A fuel cell hydrogen exhaust control device, characterized in that, include: The covariance determination module is used to determine the covariance between the stack single voltage dataset and the voltage difference dataset when the lowest single voltage of the fuel cell stack is lower than a preset alarm threshold at least twice consecutively within a target time period; the voltage difference dataset is the dataset of the difference between the stack single voltage and the stack average single voltage. The first tail exhaust control module is used to control the fuel cell to enter the hydrogen tail exhaust under the local under-gas condition of the fuel cell stack when the stack electrode is locally under-gas based on the covariance, the absolute voltage difference and the hydrogen tail exhaust cycle of the fuel cell; the absolute voltage difference is the absolute difference between the average single voltage and the lowest single voltage of the fuel cell stack. The second tail exhaust control module is used to construct a model to characterize the hydrogen purging pressure loss of the fuel cell under the working conditions of fuel cell start-up and shutdown in a defined marine application scenario, and to compensate for the hydrogen purging pressure during the start-up and shutdown phases of the fuel cell based on the model. After the fuel cell is shut down, it controls the opening of the drain valve on the fuel cell water pipeline. Based on the covariance, absolute voltage difference, and hydrogen tail gas cycle of the fuel cell, local undergassing of the stack electrodes is determined, including: The absolute voltage difference is fitted using the least squares method to obtain the first relationship; The hydrogen tail emission period was fitted using the least squares method to obtain the second relationship; If the ratio of the derivative of the first relation to the derivative of the second relation is greater than 0, and the mean of the covariance decreases, it is determined that the anode of the fuel cell stack is locally under-gasified. Based on the covariance, absolute voltage difference, and hydrogen tail gas cycle of the fuel cell, determining local undergassing of the stack electrodes further includes: If the ratio of the derivative of the first relation to the derivative of the second relation is less than or equal to 0, and the mean of the covariance increases, then a local undergassing of the cathode in the fuel cell stack is determined.

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