Water storage capacity estimation method, fuel cell drain valve control method, system and vehicle

Abstract

The present invention relates to the technical field of fuel cell systems, and specifically to a water storage capacity estimation method, a fuel cell drain valve control method, a system, and a vehicle, comprising: setting an upper threshold value and a lower threshold value of the water level in a gas-water separator; obtaining the real-time output current of the fuel cell stack, and estimating the real-time water inflow of the gas-water separator based on the real-time output current and the water production coefficient in the current drainage cycle; obtaining the valve opening signal of the ejector and the opening and closing signal of the drain valve, estimating the single-pulse drainage volume based on the valve opening signal of the ejector and the opening and closing signal of the drain valve, and estimating the real-time drainage volume of the gas-water separator based on the single-pulse drainage volume and the drainage volume correction coefficient; estimating the real-time water storage volume of the gas-water separator based on the real-time water inflow and real-time drainage volume of the gas-water separator, and combining the water storage volume of the gas-water separator at the previous moment. The present invention can achieve real-time estimation of the water storage volume in the gas-water separator without adding additional sensors.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell systems, and in particular to a water storage capacity estimation method, a fuel cell drain valve control method, a system, and a vehicle. Background Art

[0002] In the field of fuel cell technology, the gas-water separator plays a vital role. It is a key component in the fuel cell anode system, with its primary function being to separate and temporarily store liquid water from the gas-liquid mixture. During fuel cell operation, a certain amount of liquid water is produced on the anode side, where it mixes with hydrogen to form a gas-liquid mixture. The gas-water separator effectively separates the liquid water from the mixture and temporarily stores it, ensuring that hydrogen can flow smoothly through the channels and maintain the normal operation of the fuel cell stack.

[0003] The amount of water stored within the gas-water separator has a significant impact on the operation of the fuel cell system in many aspects, directly related to the patency of the hydrogen channels and the economic efficiency of the entire system. When the liquid level in the gas-water separator is too high, liquid water may accumulate, causing anode flooding. Once anode flooding occurs, the hydrogen transmission channel will be blocked by liquid water, resulting in a poor hydrogen supply and the inability to carry out normal chemical reactions within the fuel cell stack. This can seriously affect the performance output of the fuel cell stack, significantly reducing the power generation efficiency of the fuel cell, and may even damage the fuel cell stack and shorten its service life.

[0004] Conversely, if the liquid level in the gas-water separator is too low, during the drainage process, due to insufficient water level, the drainage operation may cause some hydrogen to be discharged from the system along with the liquid water, resulting in unwarranted hydrogen emissions. Hydrogen is a key reactant in fuel cells, and its emission not only wastes energy and increases the system's energy consumption costs, but also reduces hydrogen utilization efficiency, affecting the economic efficiency of the entire fuel cell system.

[0005] To accurately monitor the liquid level within the gas-water separator, traditional methods rely on additional sensors to identify the liquid level. However, this approach has significant drawbacks. On the one hand, adding additional sensors increases the hardware cost of the fuel cell system, including sensor procurement, installation, and subsequent maintenance costs. On the other hand, the introduction of additional sensors complicates the system structure, increasing points of failure and potential instability. Furthermore, compatibility issues between different sensor types can complicate system integration and commissioning, further impacting system reliability and stability.

[0006] Amidst increasingly fierce competition in the automotive industry, major automakers are under immense pressure to reduce costs and increase efficiency. For fuel cell vehicles, the key challenge is how to accurately identify and intelligently control the liquid level in the gas-water separator without adding new hardware.

[0007] Therefore, it is necessary to develop a new water storage estimation method, fuel cell drain valve control method, system and vehicle. Summary of the Invention

[0008] The purpose of the present invention is to provide a water storage capacity estimation method, a fuel cell drain valve control method, a system and a vehicle, which can realize real-time estimation of the water storage capacity in the gas-water separator without adding additional sensors.

[0009] In a first aspect, a method for estimating water storage capacity according to the present invention comprises the following steps:

[0010] Set the upper and lower thresholds of the water level in the gas-water separator;

[0011] Obtain the real-time output current of the fuel cell stack and estimate the real-time water inflow of the gas-water separator based on the real-time output current and the water production coefficient during the drainage cycle;

[0012] Obtaining the valve opening signal of the ejector and the opening and closing signal of the drain valve, estimating the single pulse drainage volume based on the valve opening signal of the ejector and the opening and closing signal of the drain valve, and estimating the real-time drainage volume of the gas-water separator based on the single pulse drainage volume and the drainage volume correction coefficient;

[0013] Based on the real-time water inflow and real-time water outflow of the gas-water separator and in combination with the water storage capacity of the gas-water separator at a previous moment, the real-time water storage capacity of the gas-water separator is estimated.

[0014] Optionally, the upper threshold is ,α∈[0.7,0.9], where is the highest water level of the gas-water separator; the lower limit threshold is , β∈[0.1,0.2]. By setting the upper threshold, we can avoid problems such as flooding of the stack anode caused by excessively high water level in the gas-water separator. By setting the lower threshold, we can avoid hydrogen overflow caused by excessively low water level.

[0015] Optionally, the real-time water inflow of the gas-water separator is estimated as follows:

[0016] Build a real-time water inflow estimation model: ;

[0017] in, is the estimated real-time water inflow of the gas-water separator, in g; The water production coefficient of the gas-water separator during this drainage cycle, in g / C; is the real-time output current of the battery stack, in A; is the iteration step time of the real-time water inflow estimation model, in seconds; is the water production coefficient in the initial drainage period, in g / C; F is the Faraday constant, in C / mol; , unit: g / mol, n is the number of electrons transferred in the electrochemical reaction, n=4;

[0018] The real-time output current of the fuel cell stack is input into a real-time water inflow estimation model, which is used to estimate the real-time water inflow of the gas-water separator. This real-time water inflow estimation model comprehensively considers factors such as the real-time output current of the fuel cell stack and the water production coefficient. By acquiring current data in real time and substituting it into the real-time water inflow estimation model, the real-time water inflow of the gas-water separator can be estimated relatively accurately.

[0019] Optionally, estimate the real-time water discharge of the gas-water separator, specifically:

[0020] Build a real-time water discharge estimation model: ;

[0021] in, Real-time water discharge of the gas-water separator; The drain valve opening time; It is the stabilization time before and after the drain valve opens and closes; is the displacement correction factor; The opening difference of the ejector before and after a single short pulse drainage;

[0022] The ejector opening difference before and after a single short-pulse drainage event and the drain valve opening time are input into a real-time drainage estimation model. This model then estimates the real-time drainage capacity of the gas-water separator. By recording the ejector opening difference before and after a single short-pulse drainage event and combining it with parameters such as the drain valve opening time and stabilization time, the real-time drainage capacity of the gas-water separator can be estimated relatively accurately using this model.

[0023] Optionally, it also includes:

[0024] After each drainage reaches the lower limit threshold, the water production coefficient is corrected and the corrected water production coefficient is used as the water production coefficient in the next drainage cycle. The correction method of the water production coefficient is as follows:

[0025] ;

[0026] ;

[0027] in, is the corrected water production coefficient; is the sliding equalization coefficient; is the water production coefficient of the gas-water separator during this drainage cycle; is the actual water production coefficient of the gas-water separator during this drainage cycle; The starting point of this drainage cycle is the moment when the air-water separator reaches the upper threshold for the first time and starts to perform short-pulse drainage; The end point of this drainage cycle is the moment when the liquid level of the air-water separator drops to the lower threshold and stabilizes after multiple short pulse drainages; The total amount of water entering the air-water separator during this drainage cycle; The real-time water inflow to the gas-water separator; The total drainage volume of the gas-water separator during this drainage cycle; Real-time water discharge of the gas-water separator; Estimated water production of the cathode during this drainage cycle; Estimate real-time water production for cathodes; is the upper threshold; The lower threshold is denoted by . By dynamically correcting the water production coefficient, key parameters in the real-time water inflow estimation model can be continuously adjusted to better align with actual operating conditions. As a fuel cell system's operating time increases, its operating conditions and water production characteristics may change. The corrected water production coefficient can better reflect these changes, thereby improving the long-term accuracy of water inflow estimation and providing a reliable foundation for the continuous optimization of drainage control strategies.

[0028] In a second aspect, a fuel cell drain valve control method according to the present invention comprises the following steps:

[0029] When the fuel cell is started, the drain valve is initially closed, and the real-time water storage capacity in the gas-water separator is calculated;

[0030] Control the opening and closing status of the drain valve according to the real-time water storage volume;

[0031] The real-time water storage capacity in the gas-water separator is calculated using the water storage capacity estimation method described in the present invention.

[0032] Optionally, the opening and closing state of the drain valve is controlled according to the real-time water storage amount, specifically:

[0033] If the real-time water storage capacity of the gas-water separator is less than or equal to the upper threshold, the drain valve is kept closed;

[0034] If the real-time water storage volume is greater than the upper threshold, an opening request is sent to the drain valve to prepare for the first short pulse drainage and record the time as After each short pulse drainage, the real-time water storage volume is monitored again. If the real-time water storage volume is still greater than the lower limit threshold, a single short pulse drainage is started again until the water storage volume in the gas-water separator is less than or equal to the lower limit threshold. This time is recorded as , and keeps the drain valve closed. By comparing the real-time water storage level with upper and lower thresholds and controlling the drain valve's opening and closing status based on the comparison results, precise control of the drainage process is achieved. When the real-time water storage level is less than or equal to the upper threshold, the drain valve remains closed, avoiding unnecessary drainage operations. When the real-time water storage level exceeds the upper threshold, drainage is initiated, ensuring the water level in the gas-water separator does not rise too high, preventing drainage obstruction and system failure. A short-pulse drainage method is used, and the real-time water storage level is monitored again after each short-pulse drainage. The comparison between the real-time water storage level and the lower threshold determines whether to initiate another short-pulse drainage cycle until the water level in the gas-water separator falls below or equals the lower threshold. This control method prevents the water level in the gas-water separator from falling too low due to excessive drainage, thereby reducing the risk of hydrogen leakage during the drainage process. It also ensures that the water level in the gas-water separator is effectively controlled within a reasonable range, preventing excessive water levels due to insufficient drainage, thereby improving system safety and reliability.

[0035] In a third aspect, a water storage estimation system described in the present invention includes a first memory and a first controller, wherein a first computer-readable program is stored in the first memory, and when the first computer-readable program is called by the first controller, it can execute the steps of the water storage estimation method described in the present invention.

[0036] In a fourth aspect, a fuel cell drain valve control system described in the present invention includes a second memory and a second controller, wherein a second computer-readable program is stored in the second memory, and when the second computer-readable program is called by the second controller, it can execute the steps of the fuel cell drain valve control method described in the present invention.

[0037] In a fifth aspect, a vehicle according to the present invention adopts the fuel cell drain valve control system according to the present invention.

[0038] Beneficial effects of the present invention:

[0039] (1) Reduced system cost and complexity: The present invention does not require the addition of additional sensor equipment. Instead, it can achieve real-time estimation of the water storage capacity in the gas-water separator based solely on the most basic sensor signals already present in the fuel cell system (such as ejector opening information, drain valve opening and closing signals, and real-time stack output current). This avoids the increased cost, increased system complexity, and potential compatibility issues associated with the introduction of new sensors, helping to reduce the overall manufacturing cost and maintenance difficulty of the fuel cell system, and improving the system's economy and reliability.

[0040] (2) Accurate water storage estimation to ensure safe and stable system operation: The present invention can more accurately estimate the real-time water storage capacity in the gas-water separator. This precise estimation can avoid drainage obstruction caused by excessively high liquid levels, which may lead to system failure or performance degradation. It can also prevent hydrogen leakage during drainage caused by excessively low liquid levels, thereby ensuring the safe and stable operation of the fuel cell system and effectively reducing safety risks.

[0041] (3) Efficient drainage control strategy to improve system performance and economy: Based on the real-time estimation of the water storage capacity in the gas-water separator, the present invention can formulate and implement an efficient drainage control strategy to accurately control the water level in the gas-water separator between the upper and lower thresholds.

[0042] (4) Enhanced system adaptability and flexibility: Since the present invention only relies on existing basic sensor signals, it can be easily adapted to different types of fuel cell systems without the need for large-scale system modifications. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a schematic structural diagram of a fuel cell system in an embodiment of the present application;

[0044] Figure 2 This is a schematic structural diagram of the gas-water separator in the embodiment of the present application;

[0045] Figure 3 This is one of the flow charts of the water storage capacity estimation method described in the embodiments of this application;

[0046] Figure 4 This is the second flow chart of the water storage capacity estimation method described in the embodiment of this application;

[0047] Figure 5 This is one of the flow charts of the fuel cell drain valve control method described in the embodiment of the present application;

[0048] Figure 6 This is the second flow chart of the fuel cell drain valve control method described in the embodiment of the present application;

[0049] Figure 7 This is a functional block diagram of the water storage capacity estimation system described in an embodiment of the present application;

[0050] Figure 8 This is a principle block diagram of the fuel cell drain valve control system described in an embodiment of the present application;

[0051] In the figure: 1-gas-water separator, 2-drain valve, 3-ejector, 4-fuel cell controller, 5-fuel cell stack, 6-first memory, 7-first controller, 8-second memory, 9-second controller. DETAILED DESCRIPTION

[0052] The following will describe the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art will be able to understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for the purpose of illustrating the present invention and are not intended to limit the scope of protection of the present invention.

[0053] like Figure 3 As shown, in an embodiment of the present application, a method for estimating water storage capacity includes the following steps:

[0054] Set the upper and lower thresholds of the water level in the gas-water separator 1. Obtain the real-time output current of the fuel cell stack 5, and estimate the real-time water intake of the gas-water separator 1 based on the real-time output current and the water production coefficient during this drainage cycle. Obtain the valve opening signal of the ejector 3 and the opening and closing signal of the drain valve 2, and estimate the single-pulse drainage volume based on the valve opening signal of the ejector 3 and the opening and closing signal of the drain valve 2, and estimate the real-time drainage volume of the gas-water separator 1 based on the single-pulse drainage volume and the drainage volume correction coefficient. Estimate the real-time water storage capacity of the gas-water separator 1 based on the real-time water intake and real-time drainage volume of the gas-water separator 1, and in combination with the water storage capacity of the gas-water separator 1 at the previous moment.

[0055] like Figure 2 As shown, in a possible embodiment, in order to avoid the problem that the water level in the gas-water separator 1 is too high and the anode of the stack 5 is flooded, an upper limit threshold (i.e. ), whose value can be , α ∈[0.7,0.9], the specific value can be obtained through calibration, is the highest water level of the gas-water separator. Similarly, to avoid hydrogen overflow due to too low water level, a lower limit threshold (i.e. ), whose value can be , β ∈[0.1,0.2], the specific value can be obtained through calibration.

[0056] In one possible embodiment, during fuel cell operation, the cathode of the stack 5 generates water through an electrochemical reaction, some of which diffuses into the anode cavity. Based on the electrochemical reaction mechanism occurring at the cathode, the amount of water purged from the anode cavity into the air-water separator 1 (i.e., the real-time water inflow into the air-water separator 1) is estimated as follows:

[0057] Build a real-time water inflow estimation model: .

[0058] in, is the estimated real-time water inflow of the gas-water separator, in g; is the water production coefficient of the gas-water separator during this drainage cycle, in g / C. K is the sequence number of the drainage cycle; is the real-time output current of the battery stack, in A; is the iteration step time of the real-time water inflow estimation model, in seconds; is the water production coefficient during the initial drainage period, in g / C; F is the Faraday constant, F=96485, in C / mol.

[0059] The obtained real-time output current of the fuel cell stack 5 is input into the real-time water inlet estimation model, and the real-time water inlet estimation model is used to estimate the real-time water inlet of the gas-water separator 1 .

[0060] In one possible embodiment, The method for determining is as follows:

[0061] Calculate the mass of water produced by the electrochemical reaction at the cathode:

[0062] , .

[0063] in, is the mass of water generated by the electrochemical reaction at the cathode; n is the number of electrons transferred by the electrochemical reaction, n=4; F is the Faraday constant; is the relative molecular mass of water, =18, unit is g / mol; Q is the charge generated in the electrochemical reaction process, unit is C; I is the output current of the battery stack, unit is A.

[0064] So we have: ; you can get: , where the unit of 18 is g / mol and the unit of F is C / mol, so The unit is g / C, The unit is (g / C)×C=g.

[0065] In a possible embodiment, in order to avoid the lag in the opening and closing request and response of the drain valve 2, the method obtains the real-time water storage capacity (i.e., liquid level) in the gas-water separator 1 through iterative calculation. When the liquid level in the gas-water separator 1 is greater than the upper limit threshold, multiple short pulse drainage is performed until the drainage is stopped when the liquid level drops to the lower limit threshold.

[0066] After drain valve 2 opens, the water storage in gas-water separator 1 decreases, reducing the air path resistance. To maintain the inlet pressure at the set operating value, ejector 3 adjusts its opening downward. Therefore, it can be assumed that the change in ejector 3's opening is proportional to the amount of water discharged. The difference in ejector 3's opening before and after a single short drainage pulse is recorded; this difference corresponds to the effect of the water discharged on the air path resistance.

[0067] Estimate the real-time drainage volume of the gas-water separator 1, specifically:

[0068] Build a real-time water discharge estimation model: .

[0069] in, ; ; ; .

[0070] in, is the opening of the ejector before a single short pulse drainage; It is the stabilization time before and after the drain valve opens and closes, which can be 0.05s; The drain valve opening time; is the ejector opening at time t; The opening of the ejector after a single short pulse drainage; The drain valve closing time; The opening difference of the ejector before and after a single short pulse drainage; is the displacement of a single short pulse (i.e., single pulse displacement); is the displacement correction factor, which can be obtained through calibration; is the real-time drainage volume of the gas-water separator; t is the real-time time.

[0071] The opening difference of the ejector 3 before and after a single short pulse drainage and the opening time of the drainage valve 2 are input into the real-time drainage estimation model, and the real-time drainage of the gas-water separator 1 is estimated by the real-time drainage estimation model.

[0072] In a possible embodiment, the real-time water storage capacity of the gas-water separator 1 is estimated as follows:

[0073] .

[0074] in, is the water storage capacity in the gas-water separator at time t; is the water storage capacity in the gas-water separator at time t-1.

[0075] like Figure 4As shown, in a possible embodiment, after each drainage reaches the lower limit threshold, the water production coefficient is corrected by the total drainage volume in the current drainage cycle, so that the estimation of the next drainage cycle is more accurate. The correction method of the water production coefficient is as follows:

[0076] ;

[0077] ;

[0078] ;

[0079] .

[0080] in, is the starting point of this drainage cycle, and the moment before the air-water separator reaches the upper threshold for the first time and starts to perform multiple short pulse drainage. At this time, the water storage capacity in the water separator is approximately the upper threshold; t N This is the end point of this drainage cycle, when the liquid level of the air-water separator drops to the lower threshold and stabilizes after multiple short pulse drainages. At this time, the water storage capacity in the water separator is approximately the lower threshold; is the actual water production coefficient of the gas-water separator during this drainage cycle; is the corrected water production coefficient; The total amount of water entering the air-water separator during this drainage cycle; The real-time water inflow to the gas-water separator; The total drainage volume of the gas-water separator during this drainage cycle; Real-time water discharge of the gas-water separator; Estimated water production of the cathode during this drainage cycle; Estimate real-time water production for cathodes; is the change in water storage capacity in the gas-water separator; is the water storage capacity in the gas-water separator at time t0; is the internal time t of the gas-water separator N Water storage capacity at is the sliding averaging coefficient, which can be obtained by calibration.

[0081] like Figure 1 As shown, during the operation of the fuel cell, the gas-liquid mixture (hydrogen, nitrogen and water) in the anode pipeline flows through the fuel cell stack 5 and then passes through the gas-water separator 1 for separation and temporary storage of liquid water.

[0082] like Figure 2 As shown, in order to ensure the performance, safety and economy of the fuel cell system, the water level needs to be controlled between the upper and lower thresholds. Therefore, it is crucial to obtain the water storage amount in the gas-water separator 1 in real time to accurately realize the opening and closing control of the drain valve 2.

[0083] like Figure 5 As shown, in an embodiment of the present application, a fuel cell drain valve control method includes the following steps:

[0084] When the fuel cell is started, the drain valve is initially closed, and the real-time water storage capacity in the gas-water separator 1 is calculated.

[0085] The opening and closing state of the drain valve 2 is controlled according to the real-time water storage amount.

[0086] The real-time water storage capacity in the gas-water separator 1 is calculated using the water storage capacity estimation method in the embodiment of the present application.

[0087] In one possible embodiment, the fuel cell has already drained the water stored in the gas-water separator 1 when it was last shut down. Therefore, during this startup, the drain valve 2 is initially closed. The fuel cell controller (FCCU) 4 receives in real time the valve opening information from the hydrogen ejector 3, the real-time output current of the fuel cell stack 5, and the opening and closing signals of the drain valve 2. The real-time water storage capacity in the gas-water separator 1 is estimated according to the water storage capacity estimation method in the embodiment of the present application, i.e. .

[0088] like Figure 6 As shown, in a possible embodiment, the opening and closing state of the drain valve 2 is controlled according to the real-time water storage amount, specifically:

[0089] If the real-time water storage capacity of the gas-water separator 1 is less than or equal to the upper threshold, the valve is kept closed. If the real-time water storage capacity is greater than the upper threshold, the fuel cell controller 4 sends an opening request to the drain valve 2, preparing for the first short-pulse drainage (the drain valve 2 opens and closes quickly, for example, the opening time is 0.1s-0.3s) and records this time as t0. After each short-pulse drainage, the real-time water storage capacity is monitored again. If the real-time water storage capacity is still greater than the lower threshold, a single short-pulse drainage is started again until the water storage capacity is less than or equal to the lower threshold, and this time is recorded as t N , keep drain valve 2 closed. At the same time, accumulate t0 to t N The total amount of water discharged from the gas-water separator 1 in the drainage cycle is calculated based on this, that is, , the total amount of water inlet to the gas-water separator 1 during the drainage cycle is divided by the estimated cathode water production during the drainage cycle (i.e. ), and obtain the modified water production coefficient (i.e. ).

[0090] like Figure 7As shown, in an embodiment of the present application, a water storage capacity estimation system includes a first memory 6 and a first controller 7. The first memory 6 stores a first computer-readable program. When the first computer-readable program is called by the first controller 7, it can execute the steps of the water storage capacity estimation method in the embodiment of the present application.

[0091] like Figure 8 As shown, in an embodiment of the present application, a fuel cell drain valve control system includes a second memory 8 and a second controller 9. The second memory 8 stores a second computer-readable program. When the second computer-readable program is called by the second controller 9, it can execute the steps of the fuel cell drain valve control method in the embodiment of the present application.

[0092] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for estimating water storage capacity, characterized in that: The following steps are involved: Setting an upper threshold and a lower threshold of the water level in the gas-water separator (1); The real-time output current of the battery stack (5) is obtained, and the real-time water inflow of the gas-water separator (1) is estimated based on the real-time output current and the water production coefficient in this drainage cycle, specifically: Build a real-time water inflow estimation model: ; in, is the estimated real-time water inflow of the gas-water separator, in g; The water production coefficient of the gas-water separator during this drainage cycle, in g / C; is the real-time output current of the battery stack, in A; is the iteration step time of the real-time water inflow estimation model, in seconds; is the water production coefficient in the initial drainage period, in g / C; F is the Faraday constant, in C / mol; =18, unit: g / mol, n is the number of electrons transferred in the electrochemical reaction, n=4; Inputting the obtained real-time output current of the battery stack (5) into a real-time water inlet estimation model, and estimating the real-time water inlet of the gas-water separator (1) by using the real-time water inlet estimation model; The valve opening signal of the ejector (3) and the opening and closing signal of the drain valve (2) are obtained, and the single pulse drainage volume is estimated based on the valve opening signal of the ejector (3) and the opening and closing signal of the drain valve (2). The real-time drainage volume of the gas-water separator (1) is estimated based on the single pulse drainage volume and the drainage volume correction coefficient. Specifically, Build a real-time water discharge estimation model: ； in, Real-time water discharge of the gas-water separator; The drain valve opening time; It is the stabilization time before and after the drain valve opens and closes; is the displacement correction factor; The opening difference of the ejector before and after a single short pulse drainage; Inputting the ejector opening difference before and after the single short pulse drainage and the opening time of the drainage valve (2) into the real-time drainage estimation model, and estimating the real-time drainage of the gas-water separator (1) through the real-time drainage estimation model; Based on the real-time water inflow and real-time water outflow of the gas-water separator (1), and in combination with the water storage capacity of the gas-water separator (1) at the previous moment, the real-time water storage capacity of the gas-water separator (1) is estimated.

2. The water storage capacity estimation method according to claim 1, characterized in that: The upper threshold is ,α∈[0.7,0.9], where is the highest water level of the gas-water separator; the lower limit threshold is , β∈[0.1,0.2].

3. The water storage capacity estimation method according to claim 1, characterized in that: Also includes: After each drainage reaches the lower limit threshold, the water production coefficient is corrected and the corrected water production coefficient is used as the water production coefficient in the next drainage cycle. The correction method of the water production coefficient is as follows: ； ； in, is the corrected water production coefficient, in g / C; is the sliding equalization coefficient; The water production coefficient of the gas-water separator during this drainage cycle, in g / C; is the actual water production coefficient of the gas-water separator during this drainage cycle; t0 is the starting point of this drainage cycle, which is the time before the gas-water separator reaches the upper threshold for the first time and starts to perform short pulse drainage; t N The end point of this drainage cycle is the moment when the liquid level of the air-water separator drops to the lower threshold and stabilizes after multiple short pulse drainages; The total amount of water entering the air-water separator during this drainage cycle; The real-time water inflow to the gas-water separator; The total drainage volume of the gas-water separator during this drainage cycle; Real-time water discharge of the gas-water separator; Estimated water production of the cathode during this drainage cycle; Estimate real-time water production for cathodes; is the upper threshold; is the lower threshold.

4. A fuel cell drain valve control method, characterized in that: The following steps are involved: When the fuel cell is started, the drain valve (2) is initially closed, and the real-time water storage amount in the gas-water separator (1) is calculated; Controlling the opening and closing state of the drain valve (2) according to the real-time water storage amount; The real-time water storage capacity in the gas-water separator (1) is calculated using the water storage capacity estimation method according to any one of claims 1 to 3.

5. The fuel cell drain valve control method according to claim 4, characterized in that: The opening and closing state of the drain valve (2) is controlled according to the real-time water storage volume, specifically: If the real-time water storage capacity of the gas-water separator (1) is less than or equal to the upper threshold value, the drain valve (2) is kept closed; If the real-time water storage volume is greater than the upper threshold, an opening request is sent to the drain valve (2) to prepare for the first short pulse drainage and record the time as t0. After each short pulse drainage, the real-time water storage volume is monitored again. If the real-time water storage volume is still greater than the lower threshold, a single short pulse drainage is started again until the water storage volume in the gas-water separator (1) is less than or equal to the lower threshold. The time is recorded as t N , and keep the drain valve (2) closed.

6. A water storage capacity estimation system, characterized by: The invention comprises a first memory (6) and a first controller (7), wherein a first computer-readable program is stored in the first memory (6), and when the first computer-readable program is called by the first controller (7), the steps of the water storage capacity estimation method according to any one of claims 1 to 3 can be executed.

7. A fuel cell drain valve control system, characterized in that: The invention comprises a second memory (8) and a second controller (9), wherein the second memory (8) stores a second computer-readable program, and when the second computer-readable program is called by the second controller (9), the steps of the fuel cell drain valve control method as claimed in claim 4 or 5 can be executed.

8. A vehicle, characterized in that: The fuel cell drain valve control system according to claim 7 is adopted.

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