Drainage control method of fuel cell system, electronic equipment and storage medium

Abstract

The invention provides a drainage control method of a fuel cell system, electronic equipment and a storage medium. The fuel cell drainage control method disclosed by the embodiment of the invention comprises the following steps: acquiring a cooling liquid in-pile temperature and a current density of an electric pile in a fuel cell system; according to the cooling liquid in-pile temperature and the current density, one of the first drainage control strategy and the second drainage control strategy is used for executing drainage control so as to drain liquid water in the electric pile. The method can effectively prevent water plugging of the electric pile, and rapidly alleviate the problem of too low voltage of the electric pile monomer.

Description

Technical Field

[0001] This disclosure relates to the field of fuel cell technology, and in particular to a drainage control method, electronic device, and storage medium for a fuel cell system. Background Technology

[0002] As a clean and efficient energy technology, fuel cell systems can be applied in scenarios such as power plants, homes, and vehicles.

[0003] The normal operation of a fuel cell system (FCS) depends on the operating conditions of the stack anode, stack cathode, and thermal management, as well as the content and distribution of liquid water inside the stack. For certain fuel cell systems, such as those using a single ejector architecture for hydrogen cycling, under low electrical density conditions, the flow rates of both hydrogen and air are relatively low. If drainage inside the stack is inadequate, water blockage can easily occur, leading to excessively low voltage in individual cells. Prolonged blockage can also cause internal leakage in the stack's membrane electrode assembly (MEA).

[0004] Currently, related technologies mainly address the problem of poor drainage within the fuel cell stack by modifying the structure of the fuel cell system, the connection relationships between components, or the structure of specific components (e.g., bipolar plates). This approach is costly, has a long optimization cycle, and cannot quickly alleviate the low-pressure problem in individual fuel cell stacks. Therefore, how to improve the drainage within the fuel cell stack without altering the fuel cell system structure is an urgent problem to be solved. Summary of the Invention

[0005] In view of this, the present disclosure provides a drainage control method, electronic equipment and storage medium for a fuel cell system, which can effectively prevent water blockage inside the fuel cell stack without changing the structure of the fuel cell system.

[0006] According to a first aspect of this disclosure, a drainage control method for a fuel cell system is provided. The method includes: acquiring the coolant inlet temperature and current density of the fuel cell stack in the fuel cell system; and performing drainage control using one of a first drainage control strategy and a second drainage control strategy to discharge liquid water inside the fuel cell stack based on the coolant inlet temperature and current density. Specifically, if the target load current is less than a predetermined load current threshold, one or more of the following parameters in the first drainage control strategy are greater than the values ​​of the same parameters in the second drainage control strategy: operating current under the same target load current, switching frequency of the nitrogen purging valve, and switching frequency of the drain valve; if the target load current is greater than or equal to the predetermined load current threshold, one or more of the following parameters in the first drainage control strategy are equal to the values ​​of the same parameters in the second drainage control strategy: operating current under the same target load current, switching frequency of the nitrogen purging valve, and switching frequency of the drain valve.

[0007] In some possible implementations of the first aspect of this disclosure, the use of one of a first drainage control strategy and a second drainage control strategy to perform drainage control to discharge liquid water inside the fuel cell stack includes:

[0008] Compare the coolant inlet temperature with a first predetermined threshold, and the current density with a second predetermined threshold;

[0009] In response to the duration during which the coolant inlet temperature is less than or equal to the first predetermined threshold being greater than or equal to the first predetermined duration, drainage control is performed using the first drainage control strategy.

[0010] In response to the duration when the coolant inlet temperature is greater than the first predetermined threshold and the current density is less than or equal to the second predetermined threshold for a duration greater than or equal to the second predetermined duration, the first drainage control strategy and the second drainage control strategy are used alternately to perform drainage control.

[0011] In some possible implementations of the first aspect of this disclosure, the step of using one of a first drainage control strategy and a second drainage control strategy to perform drainage control to discharge liquid water inside the fuel cell stack further includes:

[0012] In response to the coolant inlet temperature being greater than the first predetermined threshold and the current density being greater than the second predetermined threshold, the drainage control is performed using the second drainage control strategy.

[0013] In response to the fact that the duration during which the coolant inlet temperature is less than or equal to the first predetermined threshold is less than the first predetermined duration, the drainage control is performed using the second drainage control strategy.

[0014] In response to the duration during which the coolant inlet temperature is greater than the first predetermined threshold and the current density is less than or equal to the second predetermined threshold being less than the second predetermined duration, the drainage control is performed using the second drainage control strategy.

[0015] In some possible implementations of the first aspect of this disclosure, the alternating use of the first drainage control strategy and the second drainage control strategy to perform drainage control includes: performing drainage control once every third predetermined time interval using the first drainage control strategy.

[0016] In some possible implementations of the first aspect of this disclosure, the drainage control includes one or more of the following:

[0017] Determine the operating current corresponding to the current target load current, and control the air pressure, air flow rate, and hydrogen pressure according to the operating current;

[0018] The nitrogen venting valve is controlled to perform switching actions according to a predetermined switching frequency;

[0019] The drain valve is controlled to perform switching actions according to a predetermined switching frequency.

[0020] In some possible implementations of the first aspect of this disclosure, determining the operating current corresponding to the current target load current includes:

[0021] When performing drainage control using the first drainage control strategy, the enhanced drainage mapping table is queried to obtain the first operating current corresponding to the current target load current.

[0022] When performing drainage control using the second drainage control strategy, the operation mapping table is queried to obtain the second operating current corresponding to the current target load current.

[0023] Wherein, the value of the first operating current is greater than the value of the second operating current.

[0024] In some possible implementations of the first aspect of this disclosure, the control valve for nitrogen venting performs switching actions according to a predetermined switching frequency, including:

[0025] When performing drainage control using the first drainage control strategy, the nitrogen discharge valve is controlled to perform switching actions according to a predetermined first switching frequency.

[0026] When performing drainage control using the second drainage control strategy, the nitrogen discharge valve is controlled to perform switching actions according to a predetermined second switching frequency.

[0027] The first switching frequency is greater than the second switching frequency.

[0028] In some possible implementations of the first aspect of this disclosure, the control drain valve performs switching actions according to a predetermined switching frequency, including:

[0029] When performing drainage control using the first drainage control strategy, the control drain valve is queried and the switching action is performed according to the predetermined third switching frequency;

[0030] When performing drainage control using the second drainage control strategy, the control drain valve is switched on and off according to a predetermined fourth switching frequency.

[0031] The third switching frequency is greater than the fourth switching frequency.

[0032] According to a second aspect of this disclosure, an electronic device is provided, comprising: one or more processors and a memory storing a program, the program including instructions that, when executed by the processor, cause the processor to perform the methods described above.

[0033] According to a third aspect of this disclosure, a computer-readable storage medium storing a program, the program including instructions that, when executed by one or more processors of a computing device, cause the computing device to perform the method described above.

[0034] As can be seen from the above technical solution, the embodiments of this disclosure select one of the first drainage control strategy and the second drainage strategy for drainage control based on the coolant inlet temperature and current density. This allows for the adoption of different drainage control strategies based on the actual situation of whether the fuel cell stack is prone to water blockage. The problem of poor drainage inside the fuel cell stack can be solved simply by switching the drainage control strategy. This can effectively prevent water blockage inside the fuel cell stack, quickly alleviate the problem of low pressure in individual fuel cell stacks, and does not require changes to the structure of the fuel cell system. It is low in cost and easy to implement. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 A flowchart of a drainage control method for a fuel cell system provided in an embodiment of this disclosure;

[0037] Figure 2 This is a flowchart illustrating the drainage control steps involved in the embodiments of this disclosure;

[0038] Figure 3 This is a flowchart illustrating the execution of a primary drainage control according to an embodiment of this disclosure;

[0039] Figure 4 This is a schematic diagram of the structure of a fuel cell system drainage control device provided in an embodiment of this disclosure;

[0040] Figure 5 A schematic structural block diagram of an electronic device provided in an embodiment of this disclosure. Detailed Implementation

[0041] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0042] The terminology used in the embodiments of this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The singular forms “a,” “the,” and “the” as used in the embodiments of this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0043] Depending on the context, words such as "if," "when," etc., used here can be interpreted as "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrases "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0044] As mentioned above, related technologies mainly address the problem of poor drainage within the fuel cell stack by modifying the structure of the fuel cell system. This approach is costly, has a long optimization cycle, and cannot quickly alleviate the low-pressure problem of individual fuel cell stacks. Therefore, this disclosure provides the following fuel cell system and its drainage control method, apparatus, electronic equipment, and storage medium. Drainage control is performed by selecting one of a first drainage control strategy and a second drainage strategy based on the coolant inlet temperature and current density. Different drainage control strategies can be adopted depending on the actual situation of whether the fuel cell stack is prone to water blockage. The problem of poor drainage within the fuel cell stack can be solved simply by switching between different control strategy logics. This effectively prevents water blockage within the fuel cell stack, quickly alleviates the low-pressure problem of individual fuel cell stacks, requires no changes to the structure of the fuel cell system, and is low-cost and easy to implement.

[0045] For ease of understanding, the fuel cell system provided in the embodiments of this disclosure will be described below first.

[0046] This disclosure provides a fuel cell system including a fuel cell control unit (FCU) that can be used to execute the drainage control method of the fuel cell system described below.

[0047] For example, the fuel cell system of this disclosure may include: a cathode gas supply subsystem, an anode gas supply subsystem, an electronic control subsystem, a fuel cell stack, and a hydrothermal management subsystem. The electronic control system includes the aforementioned fuel cell control unit (FCU), which can be used to execute the fuel cell system drainage control method described below. The cathode gas supply subsystem is used to supply air to the fuel cell stack, the anode gas supply subsystem is used to supply oxygen to the fuel cell stack, the electronic control subsystem is used to control the operation of other parts, and the hydrothermal management subsystem is responsible for the hydrothermal management of the fuel cell stack.

[0048] In some examples, the fuel cell system has a coolant inlet and a coolant outlet. Coolant from the hydrothermal management subsystem circulates in and out of the stack through the coolant inlet and outlet to cool the stack. The coolant inlet temperature indicates the coolant temperature at the coolant inlet of the stack. In specific applications, a coolant inlet temperature sensor is installed at the coolant inlet of the stack (e.g., on the hydrothermal management channel near the cold zone coolant inlet). This sensor is electrically connected to the fuel cell controller to detect the coolant inlet temperature in real time and provide this information to the controller.

[0049] In some examples, the fuel cell system has an air inlet at the cathode and a hydrogen inlet at the anode. Air processed by the cathode gas supply subsystem enters the fuel cell stack through the air inlet at the cathode, while hydrogen from the anode gas supply subsystem enters the stack through the hydrogen inlet at the anode. An air inlet pressure sensor is installed on the air duct at the air inlet (which belongs to the cathode gas supply subsystem), and this sensor is electrically connected to the fuel cell controller to monitor the air inlet pressure in real time and provide this information. Similarly, a hydrogen inlet pressure sensor is installed on the hydrogen duct at the hydrogen inlet (which may belong to the anode gas supply subsystem), and this sensor is electrically connected to the fuel cell controller to monitor the hydrogen inlet pressure in real time and provide this information.

[0050] In some examples, fuel cell systems may also include an air compressor, an air flow meter, an air back pressure valve, and a hydrogen injection proportional valve. During operation, the fuel cell system achieves higher power output by controlling air pressure, air flow rate, and hydrogen pressure. In specific applications, the air flow rate can be controlled by the air compressor. Air pressure can be controlled by controlling the air flow rate and the opening of the air back pressure valve, while hydrogen pressure can be controlled by controlling the opening of the hydrogen injection proportional valve.

[0051] In some examples, the fuel cell system may also include a nitrogen venting valve, which is used to vent nitrogen gas that has permeated from the cathode into the anode circulation area of ​​the fuel cell stack, while also venting a small amount of hydrogen gas. Since nitrogen gas on the cathode side of the fuel cell stack can pass through the proton exchange membrane into the anode side during operation, the main purpose of the nitrogen venting valve is to vent nitrogen gas from the anode side. In practical applications, the nitrogen venting valve is periodically opened to increase the hydrogen concentration on the anode side of the fuel cell stack.

[0052] In some examples, the fuel cell system may also include a drain valve and a gas-liquid separator. Hydrogen permeating from the anode to the cathode reacts with air to produce water vapor. This water vapor is separated into liquid water by the gas-liquid separator and collected in a collection box. When the drain valve is opened, the liquid water in the collection box is discharged. Therefore, the drain valve can be used to drain the liquid water generated inside the fuel cell stack.

[0053] In other words, the fuel cell system provided in this disclosure can be applied to various application scenarios, such as power plants, home applications, and mobile applications like vehicles. This disclosure does not limit the specific application scenarios of the fuel cell system.

[0054] It should be noted that the fuel cell system structure described in this disclosure is merely an example. In specific applications, any other applicable structure can be used for the fuel cell system.

[0055] Figure 1 A schematic flowchart of a drainage control method for a fuel cell system provided in this disclosure is shown. The drainage control method for a fuel cell system provided in this disclosure can be executed by the fuel cell controller in the fuel cell system. See also... Figure 1 The method in this disclosure embodiment may include:

[0056] Step 101: Obtain the coolant inlet temperature and current density of the fuel cell stack in the fuel cell system;

[0057] Step 102: Based on the coolant inlet temperature and current density, perform drainage control using either the first drainage control strategy or the second drainage control strategy to drain the liquid water inside the fuel cell stack.

[0058] If the target load current is less than the predetermined load current threshold, one or more of the following parameters in the first drainage control strategy are greater than the values ​​of the same parameters in the second drainage control strategy: 1) the operating current under the same target load current; 2) the switching frequency of the nitrogen venting valve; 3) the switching frequency of the drainage valve. Therefore, under the same operating conditions, the parameter values ​​in the first drainage control strategy are higher than those in the second drainage control strategy, meaning the drainage intensity of the first drainage control strategy is higher than that of the second drainage control strategy.

[0059] If the target load current is less than the predetermined load current threshold, one or more of the following parameters in the first drainage control strategy will be greater than the values ​​of the same parameters in the second drainage control strategy: 1) the operating current under the same target load current; 2) the switching frequency of the nitrogen purging valve; 3) the switching frequency of the drainage valve. Therefore, when the target load current reaches a certain level, the parameter values ​​in the first drainage control strategy can be the same as those in the second drainage control strategy under the same operating conditions, in order to better protect components such as the fuel cell stack and extend the service life of critical components such as the fuel cell stack in the fuel cell system.

[0060] In practical applications, the load current threshold can be flexibly set according to the specific conditions of the fuel cell system and its application scenario. In some examples, the load current threshold can be set to any value between 330A and 450A, where "A" represents amperes.

[0061] Furthermore, in the first drainage control strategy, different switching frequencies for the nitrogen discharge valve and / or the drainage valve can be set for different load currents. This disclosure does not limit the scope of the embodiments.

[0062] In this embodiment of the disclosure, drainage control is performed by selecting one of two drainage control strategies with different intensities, based on the coolant inlet temperature and current density of the fuel cell stack in the fuel cell system. Specifically, when the coolant inlet temperature and current density of the fuel cell stack in the fuel cell system indicate that water blockage is unlikely to occur inside the stack, a second drainage control strategy that allows the stack to perform better is adopted. When the coolant inlet temperature and current density of the fuel cell stack in the fuel cell system indicate that water blockage is likely to occur inside the stack, a first drainage control strategy that strengthens drainage is adopted. Thus, the problem of poor drainage inside the stack is solved by optimizing the drainage control strategy. There is no need to change the structure of the fuel cell system, which is highly feasible, has a short optimization cycle, and low cost.

[0063] In step 101, the coolant inlet temperature can be detected in real time by the coolant temperature sensor and then provided to the fuel cell controller.

[0064] In step 101, the current density can be obtained in real time by measuring the output power, output voltage, and output current of the fuel cell stack from the fuel cell controller.

[0065] In step 101, the coolant inlet temperature and current density can be detected in real time so that the drainage control strategy can be adjusted in real time in step 201.

[0066] In practical applications, it has been found that the coolant inlet temperature and current density directly reflect whether the fuel cell stack is in a state prone to water blockage. Specifically, when the coolant inlet temperature is less than or equal to a first predetermined threshold for a duration greater than or equal to a first predetermined duration, the fuel cell system is typically in the warm-up phase after startup. Given the limited drainage structure of the bipolar plates in the fuel cell stack and the limited hydrogen cycling capacity of the fuel cell system, the stack is prone to water blockage. When the coolant inlet temperature is greater than the first predetermined threshold and the current density is less than or equal to a second predetermined threshold for a duration greater than or equal to a second predetermined duration, the fuel cell system is typically in a stable operating phase, and the stack is also prone to water blockage. In other cases, the fuel cell stack operates in a state less prone to water blockage. Therefore, step 102 can be implemented through the following specific embodiments.

[0067] Figure 2 A flowchart illustrating a specific implementation of the fuel cell system drainage control method provided in this disclosure is shown. See also... Figure 2 As shown, step 102 may include:

[0068] Step 201: Compare the coolant inlet temperature with a first predetermined threshold and the current density with a second predetermined threshold;

[0069] Step 202: In response to the duration during which the coolant inlet temperature is less than or equal to a first predetermined threshold being greater than or equal to a first predetermined duration, drainage control is performed using a first drainage control strategy.

[0070] Step 203: In response to the duration when the coolant inlet temperature is greater than a first predetermined threshold and the current density is less than or equal to a second predetermined threshold for a duration greater than or equal to a second predetermined duration, the first drainage control strategy and the second drainage control strategy are used alternately to perform drainage control.

[0071] In some implementations, step 102 may further include the following steps:

[0072] Step 204: In response to the coolant inlet temperature being greater than a first predetermined threshold and the current density being greater than a second predetermined threshold, drainage control is performed using a second drainage control strategy.

[0073] Step 205: In response to the fact that the duration for which the coolant inlet temperature is less than or equal to the first predetermined threshold is less than the first predetermined duration, drainage control is performed using the second drainage control strategy.

[0074] Step 206: In response to the duration during which the coolant inlet temperature is greater than a first predetermined threshold and the current density is less than or equal to a second predetermined threshold being less than a second predetermined duration, drainage control is performed using a second drainage control strategy.

[0075] In step 202, a first timer can be set to time the duration for which the coolant inlet temperature is less than or equal to a first predetermined threshold. If the coolant inlet temperature is less than or equal to the first predetermined threshold, the first timer is started to time the duration for which the coolant inlet temperature is less than or equal to the first predetermined threshold. If the coolant inlet temperature is greater than the first predetermined threshold during the timing process, the timing stops and is reset to zero; otherwise, the timing can continue. It is continuously determined whether the timing duration of the first timer has reached the first predetermined duration. If the timing duration of the first timer has reached the first predetermined duration, the first drainage control strategy is used to execute drainage control; otherwise, the second drainage control strategy is continuously used to execute drainage control.

[0076] When the coolant inlet temperature is less than or equal to the first predetermined threshold for a duration greater than or equal to the first predetermined duration, the fuel cell system is typically in the warm-up phase after startup. At this time, due to the limited drainage structure of the bipolar plates in the fuel cell stack and the limited hydrogen cycling capacity of the fuel cell system, the fuel cell stack is prone to water blockage. The embodiments of this disclosure use a first drainage control strategy to enhance drainage, which can increase cathode pressure, cathode flow rate, and anode pressure, thereby enhancing the drainage capacity of the fuel cell stack, effectively preventing water blockage, and quickly alleviating the problem of low individual voltage in the fuel cell stack.

[0077] In step 203, a second timer can be set. This second timer is used to time the duration during which the coolant inlet temperature is greater than a first predetermined threshold and the current density is less than or equal to a second predetermined threshold. If the coolant inlet temperature is greater than the first predetermined threshold and the current density is less than or equal to the second predetermined threshold, the second timer is started. During the timing process, if the coolant inlet temperature is less than or equal to the first predetermined threshold or the current density is greater than the second predetermined threshold, the second timer stops timing and is reset to zero; otherwise, the second timer continues timing. It is continuously determined whether the timing duration of the second timer has reached the second predetermined duration. If the timing duration of the second timer has reached the second predetermined duration, the first drainage control strategy and the second drainage control strategy are used alternately to perform drainage control.

[0078] When the coolant inlet temperature is greater than a first predetermined threshold and the current density is less than or equal to a second predetermined threshold for a duration greater than or equal to a second predetermined duration, the fuel cell system is usually in a stable operating phase. At this time, the fuel cell stack is also prone to water blockage. In this embodiment of the present disclosure, the system switches to a first drainage control strategy to enhance drainage at regular intervals (e.g., 300s). By periodically increasing the cathode pressure, cathode flow rate, anode pressure, and increasing the switching frequency of the nitrogen venting valve and the drainage valve, pulse pressure is generated in the fuel cell stack flow channel. The drainage capacity of the fuel cell stack is improved by the pulse pressure, thereby effectively preventing water blockage in the fuel cell stack and quickly alleviating the problem of low individual voltage of the fuel cell stack.

[0079] The first predetermined threshold, the second predetermined threshold, the first predetermined duration, and the second predetermined duration are all calibrated values. The first predetermined threshold is related to the load power and warm-up time of the fuel cell system, while the first predetermined duration is related to the rate of increase and temperature fluctuation of the coolant temperature during warm-up. The values ​​of the first predetermined threshold, the second predetermined threshold, the first predetermined duration, and the second predetermined duration may differ depending on the operating conditions and application scenarios of the fuel cell system. In specific applications, the values ​​of the first predetermined threshold, the second predetermined threshold, the first predetermined duration, and the second predetermined duration can be recalibrated as needed.

[0080] For example, the first predetermined threshold can be any value between 45℃ and 55℃, and the first predetermined duration can be any value between 5 seconds and 15 seconds. For instance, the first predetermined threshold can be 50℃, the first predetermined duration can be 5 seconds, the second predetermined threshold can be 0.5, and the second predetermined duration can be 5 seconds.

[0081] In step 102, drainage control is performed by alternately using the first drainage control strategy and the second drainage control strategy, including: performing drainage control once every third predetermined time interval using the first drainage control strategy, and performing drainage control using the second drainage control strategy during the interval between using the first drainage control strategy.

[0082] The third predetermined duration can be determined based on simulation evaluation of the internal drainage effect of the fuel cell stack. The value of the third predetermined duration can vary depending on the application scenario, the fuel cell stack, and the fuel cell system architecture. For example, the third predetermined duration can be 300 seconds or other values. That is, when the coolant inlet temperature is greater than the first predetermined threshold and the current density is less than or equal to the second predetermined threshold for a duration greater than or equal to the second predetermined duration, drainage control is performed once every 300 seconds using the first drainage control strategy; at other times, drainage control can be performed using the second drainage control strategy. In this way, during the operation of the fuel cell system, drainage can be periodically enhanced using the first drainage control strategy, and drainage can also be performed using the second drainage control strategy, which has relatively better stack performance. This can reduce water blockage problems inside the fuel cell stack while ensuring stable output power of the fuel cell system.

[0083] Figure 3 A flowchart illustrating the primary drainage control in step 102 is shown. See also... Figure 3 The primary drainage control in step 102 may include one or more of the following steps 301 to 303:

[0084] Step 301: Determine the operating current corresponding to the current target load current, and control the air pressure, air flow rate and hydrogen pressure according to the operating current;

[0085] Step 302: Control the nitrogen venting valve to perform switching actions according to a predetermined switching frequency;

[0086] Step 303: Control the drain valve to perform switching actions according to the predetermined switching frequency.

[0087] In practical applications, the primary drainage control in step 102 can be performed by executing any one of steps 301, 302, and 303, or by executing any two of steps 301, 302, and 303, or by executing all of steps 301, 302, and 303 as needed. When executing all steps 301 to 303, these steps can be executed simultaneously or sequentially according to a specific order as needed.

[0088] In one example, when the first drainage control strategy is used to perform drainage control, in order to avoid the burden on hydrogen tail emissions after the enhanced pressure control in step 301, the drainage control in step 102 can be performed by only one or both of steps 302 and 303.

[0089] In one example, if the actual drainage volume is small in practical applications, the single drainage control in step 102 can be performed only in step 302.

[0090] It should be noted that, Figure 3This is merely an exemplary implementation of drainage control in this disclosure. In practical applications, this disclosure does not limit the specific implementation of the primary drainage control step in step 102.

[0091] When performing drainage control using the first drainage control strategy, step 301 can query the enhanced drainage mapping table to obtain the first operating current corresponding to the current target load current. When performing drainage control using the second drainage control strategy, step 301 can query the operation mapping table to obtain the second operating current corresponding to the current target load current, where the value of the first operating current is greater than the value of the second operating current. Therefore, the control targets for air pressure, air flow rate, and hydrogen pressure under the first drainage control strategy will be higher than those under the second drainage control strategy. Thus, the first drainage control strategy can achieve enhanced drainage, while the second drainage control strategy can achieve drainage with better stack performance.

[0092] The load current is the output current of the fuel cell stack in a gas turbine electric system, while the operating current is the execution parameter issued by the FCU to other components of the gas turbine electric system. During normal operation, the operating current of the components is the same as the load current. In this embodiment, the enhanced drainage mapping table may contain the values ​​of the first operating current corresponding to different target load currents, and the operating mapping table may contain the values ​​of the second operating current corresponding to different target load currents. The value of the first operating current corresponding to the same target load current is greater than the value of its corresponding second operating current.

[0093] Step 301, which involves controlling the air pressure, air flow rate, and hydrogen pressure based on the operating current, may include: querying an operation mapping table to obtain the control target value corresponding to the operating current, and using this control target value to control the air compressor speed, the opening degree of the air back pressure valve, and the hydrogen injection proportional valve. The control target value may include the target air compressor speed, the target air back pressure valve opening degree, and the target hydrogen injection proportional valve opening degree.

[0094] In practical applications, the first and second drainage control strategies can share the same operation mapping table. This table contains control target values ​​corresponding to different operating current values. Different operating current values ​​represent different operating conditions, and under these conditions, the control targets for air pressure, air flow rate, and hydrogen pressure differ. Generally, when the operating current value is higher, the control targets for air pressure, air flow rate, and hydrogen pressure are also relatively higher.

[0095] The following provides a detailed explanation of the specific implementation process of step 301 under different drainage control strategies.

[0096] In step 301, when performing drainage control using the first drainage control strategy, the FCU queries the enhanced drainage mapping table to find the first operating current corresponding to the current target load current, and then queries the operation mapping table to obtain the target value of the air compressor speed, the target value of the air back pressure valve opening, and the target value of the hydrogen injection proportional valve opening under the first operating current. The FCU then performs air compressor speed control to make the air compressor reach the target speed value, performs air back pressure valve opening control to make its opening reach the target value of the back pressure valve opening, and performs hydrogen injection proportional valve opening control to make its opening reach the target value of the hydrogen injection proportional valve opening.

[0097] In step 301, when performing drainage control using the second drainage control strategy, the FCU queries the operation mapping table (e.g., Control Map) to obtain the second operating current corresponding to the current target load current, as well as the target values ​​of the air compressor speed, air back pressure valve opening, and hydrogen injection proportional valve opening under the second operating current. It then performs air compressor speed control to make the air compressor reach the target speed value, performs air back pressure valve opening control to make its opening reach the target back pressure valve opening value, and performs hydrogen injection proportional valve opening control to make its opening reach the target hydrogen injection proportional valve opening value.

[0098] In step 302, when performing drainage control using the first drainage control strategy, the nitrogen venting valve is controlled to switch on and off according to a predetermined first switching frequency; when performing drainage control using the second drainage control strategy, the nitrogen venting valve is controlled to switch on and off according to a predetermined second switching frequency; wherein the first switching frequency is greater than the second switching frequency. The function of the nitrogen venting valve is to discharge nitrogen gas that has permeated from the cathode into the anode circulation of the fuel cell stack, and a small amount of hydrogen gas is also discharged. By increasing the switching frequency of the nitrogen venting valve in the first drainage control strategy, the anode gas circulation volume can be increased, thereby increasing the pressure difference between the fuel cell stack anode and the outlet, and thus improving the drainage capacity, thereby achieving enhanced drainage.

[0099] In step 303, when performing drainage control using the first drainage control strategy, the drainage valve is controlled to perform switching actions according to a predetermined third switching frequency; when performing drainage control using the second drainage control strategy, the drainage valve is controlled to perform switching actions according to a predetermined fourth switching frequency; wherein the third switching frequency is greater than the fourth switching frequency. By increasing the switching frequency of the drainage valve in the first drainage control strategy, the discharge of liquid water inside the fuel cell stack can be accelerated.

[0100] The first, second, third, and fourth switching frequencies are all calibrated values ​​and can be obtained through calibration.

[0101] For example, when the coolant inlet temperature is less than or equal to a first predetermined threshold for a duration greater than or equal to a first predetermined duration, the fuel cell system is typically in the warm-up phase after startup. In this case, the first drainage control strategy can be configured as follows: the first switching frequency can be set to {on duration 0.3–0.8 seconds; off duration 0.1–0.3 seconds}, and the second switching frequency can be set to {on duration 0.7–1.3 seconds; off duration 3–7 seconds}. As another example, when the coolant inlet temperature is greater than a first predetermined threshold and the current density is less than or equal to a second predetermined threshold for a duration greater than or equal to a second predetermined duration, the fuel cell system is typically in the stable operation phase. In this case, the first drainage control strategy can be configured as follows: the first switching frequency can be set to {on duration 0.3–0.8 seconds; off duration 0.1–0.3 seconds; duration 8–12 seconds}, and the second switching frequency can be set to {on duration 0.8–1.2 seconds; off duration 3–8 seconds; duration 6–14 seconds}.

[0102] Figure 4 A schematic diagram of the drainage control device for a fuel cell system provided in an embodiment of this disclosure is shown. See also... Figure 4 The drainage control device 400 of the fuel cell system may include:

[0103] The acquisition unit 401 is used to acquire the coolant inlet temperature and current density of the fuel cell stack in the fuel cell system.

[0104] The strategy execution unit 402 is used to perform drainage control by using one of a first drainage control strategy and a second drainage control strategy to drain the liquid water inside the fuel cell stack, based on the coolant inlet temperature and current density.

[0105] Wherein, if the target load current is less than the predetermined load current threshold, one or more of the following parameters in the first drainage control strategy are greater than the values ​​of the same parameters in the second drainage control strategy: operating current under the same target load current, switching frequency of the nitrogen vent valve, and switching frequency of the drain valve; if the target load current is greater than or equal to the predetermined load current threshold, one or more of the following parameters in the first drainage control strategy are equal to the values ​​of the same parameters in the second drainage control strategy: operating current under the same target load current, switching frequency of the nitrogen vent valve, and switching frequency of the drain valve.

[0106] Further, the strategy execution unit 402 is configured to: compare the coolant inlet temperature with a first predetermined threshold and the current density with a second predetermined threshold; in response to the duration during which the coolant inlet temperature is less than or equal to the first predetermined threshold being greater than or equal to a first predetermined duration, perform drainage control using a first drainage control strategy; and in response to the duration during which the coolant inlet temperature is greater than the first predetermined threshold and the current density is less than or equal to the second predetermined threshold being greater than or equal to a second predetermined duration, alternately use the first drainage control strategy and the second drainage control strategy for drainage control.

[0107] Further, the strategy execution unit 402 is configured to: execute drainage control using a second drainage control strategy in response to the coolant inlet temperature being greater than a first predetermined threshold and the current density being greater than a second predetermined threshold; execute drainage control using a second drainage control strategy in response to the duration during which the coolant inlet temperature is less than or equal to the first predetermined threshold being less than a first predetermined duration; and execute drainage control using a second drainage control strategy in response to the duration during which the coolant inlet temperature is greater than the first predetermined threshold and the current density is less than or equal to the second predetermined threshold being less than a second predetermined duration.

[0108] Furthermore, the strategy execution unit 402 is used to: execute drainage control once using the first drainage control strategy every third predetermined time interval.

[0109] Further, the strategy execution unit 402 is used to perform drainage control, which includes one or more of the following: 1) determining the operating current corresponding to the current target load current, and controlling the air pressure, air flow rate, and hydrogen pressure according to the operating current; 2) controlling the nitrogen venting valve to perform switching actions at a predetermined switching frequency; 3) controlling the exhaust valve to perform switching actions at a predetermined switching frequency. In specific applications, the drainage control device 400 of the fuel cell system can be implemented by software, hardware, or a combination of both. For example, the drainage control device 400 of the fuel cell system can be implemented as software running in the aforementioned fuel cell system's fuel cell controller.

[0110] Further technical details regarding the drainage control device 400 for the fuel cell system can be found in the section on drainage control methods above, and will not be repeated here.

[0111] In addition, embodiments of this disclosure also provide a computer-readable storage medium storing a computer program thereon, the program including instructions that, when executed by one or more processors of a computing device, perform the steps of the aforementioned fuel cell system drainage control method.

[0112] Figure 5 A schematic diagram of the structure of an electronic device provided in an embodiment of this disclosure is shown. This electronic device can be the main controller of the aforementioned fuel cell system. See also... Figure 5The electronic device 500 may include one or more processors 501, and a memory 502 storing one or more programs, which are executed by the one or more processors 501 to implement the method flow and / or program units corresponding to each unit in the apparatus shown in the above embodiments of this disclosure.

[0113] The various components are interconnected via different buses and can be mounted on a common motherboard or otherwise as required. Processor 501 can process instructions executed within the electronic device, including instructions stored in or on memory to display graphical information of a user interface on an external input / output device (such as a display device coupled to an interface). In other embodiments, multiple processors and / or multiple buses can be used with multiple memories and multiple memory sets, if desired.

[0114] Processor 501 may include one or more single-core or multi-core processors. Processor 501 may include any combination of general-purpose processors or special-purpose processors (such as graphics processors, application processors, baseband processors, etc.).

[0115] Memory 502 is the computer-readable storage medium provided in this disclosure, which can be used to store non-transitory software programs, non-transitory computer-executable programs, and units, such as those in the embodiments of this disclosure. Figure 1 The program instructions / units corresponding to the drainage control method of the fuel cell system shown are as follows. The processor 501 executes non-transient software programs, instructions, and units stored in the memory 502, thereby performing actions such as those described in the above method embodiments. Figure 1 The program, instructions, and units corresponding to the drainage control method of the fuel cell system shown.

[0116] The electronic device may also include an input device 503 and an output device 504. The processor 501, memory 502, input device 503, and output device 504 can be connected via a bus or other means. Figure 5 Taking the example of a connection between China and Israel via a bus.

[0117] Input device 503 can receive input digital or character information, and generate signal inputs related to user settings and function control, such as touch screens, keypads, mice, trackpads, touchpads, joysticks, one or more mouse buttons, trackballs, joysticks, etc. Output device 504 may include display devices, auxiliary lighting devices (e.g., LEDs), and haptic feedback devices (e.g., vibration motors). The display device may include, but is not limited to, liquid crystal displays (LCDs), light-emitting diode (LED) displays, and plasma displays. In some embodiments, the display device may be a touch screen.

[0118] The aforementioned programs (also known as software, software applications, or code) include the machine instructions of a programmable processor and can be implemented using object-oriented programming languages, assembly language, or machine language.

[0119] With the development of time and technology, the meaning of "medium" has become increasingly broad. The dissemination of computer programs is no longer limited to tangible media; they can also be downloaded directly from the network. Any combination of one or more computer-readable storage media can be used. Computer-readable storage media can be, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0120] In a specific implementation, the electronic device 500 can be implemented as, but is not limited to, a fuel cell controller in a fuel cell system.

[0121] The technical solutions provided in this disclosure have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this disclosure. The descriptions of the embodiments above are only for the purpose of helping to understand the methods and core ideas of this disclosure. Furthermore, those skilled in the art will recognize that, based on the ideas of this disclosure, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this disclosure.

[0122] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Any modifications or equivalent substitutions made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A drain control method of a fuel cell system, characterized by, The method comprises: acquiring a cooling liquid inlet stack temperature and a current density of a stack in the fuel cell system; performing water removal control to remove liquid water inside the stack using one of a first water removal control strategy and a second water removal control strategy according to the cooling liquid inlet stack temperature and the current density; wherein if a target load current is less than a predetermined load current threshold, one or more of the following parameters in the first water removal control strategy has a value greater than that of the same parameter in the second water removal control strategy: operating current at the same target load current, switching frequency of a nitrogen removal valve, switching frequency of a water removal valve; if the target load current is greater than or equal to the predetermined load current threshold, one or more of the following parameters in the first water removal control strategy has a value equal to that of the same parameter in the second water removal control strategy: operating current at the same target load current, switching frequency of the nitrogen removal valve, switching frequency of the water removal valve.

2. The method of claim 1, wherein, The performing water removal control to remove liquid water inside the stack using one of the first water removal control strategy and the second water removal control strategy comprises: comparing the cooling liquid inlet stack temperature with a first predetermined threshold and the current density with a second predetermined threshold; in response to a duration that the cooling liquid inlet stack temperature is less than or equal to the first predetermined threshold being equal to greater than a first predetermined time length, performing water removal control using the first water removal control strategy; in response to a duration that the cooling liquid inlet stack temperature is greater than the first predetermined threshold and the current density is less than or equal to the second predetermined threshold being greater than or equal to a second predetermined time length, alternately performing water removal control using the first water removal control strategy and the second water removal control strategy.

3. The method of claim 2, wherein, The performing water removal control to remove liquid water inside the stack using one of the first water removal control strategy and the second water removal control strategy further comprises: in response to the cooling liquid inlet stack temperature being greater than the first predetermined threshold and the current density being greater than the second predetermined threshold, performing the water removal control using the second water removal control strategy; in response to a duration that the cooling liquid inlet stack temperature is less than or equal to the first predetermined threshold being less than the first predetermined time length, performing the water removal control using the second water removal control strategy; in response to a duration that the cooling liquid inlet stack temperature is greater than the first predetermined threshold and the current density is less than or equal to the second predetermined threshold being less than the second predetermined time length, performing the water removal control using the second water removal control strategy.

4. The method of claim 2, wherein, The alternately performing water removal control using the first water removal control strategy and the second water removal control strategy comprises: performing water removal control using the first water removal control strategy once every third predetermined time length.

5. The method of claim 1, wherein, The water removal control comprises one or more of: determining an operating current corresponding to a current target load current, and performing control of air pressure, air flow rate and hydrogen pressure according to the operating current; controlling a nitrogen removal valve to perform switching action at a predetermined switching frequency; controlling a water removal valve to perform switching action at a predetermined switching frequency.

6. The method of claim 5, wherein, The determining to obtain an operating current corresponding to a current target load current comprises: When the first drainage control strategy is used to perform the drainage control, a strengthened drainage mapping table is queried to obtain a first operating current corresponding to the current target pull current; When the second drainage control strategy is used to perform the drainage control, an operating mapping table is queried to obtain a second operating current corresponding to the current target pull current; The first operating current has a value greater than that of the second operating current.

7. The method of claim 5, wherein, The control of the nitrogen discharge valve includes: When the first drainage control strategy is used to perform the drainage control, the nitrogen discharge valve is controlled to perform the switching action at a predetermined first switching frequency; When the second drainage control strategy is used to perform the drainage control, the nitrogen discharge valve is controlled to perform the switching action at a predetermined second switching frequency; The first switching frequency is greater than the second switching frequency.

8. The method of claim 5, wherein, The control of the nitrogen discharge valve includes: When the first drainage control strategy is used to perform the drainage control, the nitrogen discharge valve is controlled to perform the switching action at a predetermined third switching frequency; When the second drainage control strategy is used to perform the drainage control, the nitrogen discharge valve is controlled to perform the switching action at a predetermined fourth switching frequency; The third switching frequency is greater than the fourth switching frequency.

9. An electronic device, comprising: The control of the nitrogen discharge valve includes: One or more processors and a memory storing a program, the program including instructions that, when executed by the processors, cause the processors to perform the method of any one of claims 1-8.

10. A computer-readable storage medium storing a program, the program including instructions that, when executed by one or more processors of a computing device, cause the computing device to perform the method of any one of claims 1-8.

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