A hydrogen-oxygen fuel cell engine control system based on water thermal management

Abstract

The present invention discloses a hydrogen-oxygen fuel cell engine control system based on hydrothermal management. The control system includes a fuel cell for generating electricity using hydrogen and oxygen, a hydrogen supply unit for supplying hydrogen to the fuel cell, an air supply unit for supplying oxygen to the fuel cell engine, and a purge unit for purging. The control system also includes a diagnostic unit electrically connected to the fuel cell, the hydrogen supply unit, and the air supply unit; the diagnostic unit is configured to obtain status signals from the fuel cell, the hydrogen supply unit, and the air supply unit, and perform fault diagnosis based on the diagnostic signals; and a diagnostic control unit electrically connected to the diagnostic unit, the hydrogen supply unit, and the air supply unit; the diagnostic control unit is configured to obtain diagnostic results from the diagnostic unit and adjust the hydrogen supply unit and the air supply unit based on the diagnostic results. The present invention can diagnose and eliminate faults.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell engines, and in particular to a hydrogen-oxygen fuel cell engine control system based on hydrothermal management. Background Art

[0002] The proton exchange membrane fuel cell engine (PEMFC) is a key component in fuel cell vehicles, converting hydrogen into electricity. The PEM requires a moderate moisture content to function. Low levels of water can lead to membrane dry-out failure. If this occurs to a certain degree, the membrane shrinks, becomes brittle, and eventually cracks form. In this situation, the PEM loses its gas separation function, allowing reactant gases to cross-circulate within the cell, gradually halting energy production. Therefore, severe membrane dry-out can cause irreversible damage to the fuel cell, severely impacting the fuel cell engine's lifespan. Waterlogging can severely impact fuel cell performance and even reduce the fuel cell engine's service life.

[0003] Therefore, how to ensure that the proton exchange membrane has an appropriate moisture content is a key issue that needs to be addressed in this field. More specifically, because the moisture content in the proton exchange membrane is constantly changing, and the water between the cathode and anode sides changes dynamically with operating conditions, controlling the fuel cell engine to ensure that the proton exchange membrane has an appropriate moisture content is extremely critical. Summary of the Invention

[0004] The purpose of the present invention is to provide a hydrogen-oxygen fuel cell engine control system based on water thermal management to address the deficiencies in the prior art. It can enable the proton exchange membrane to have an appropriate water content to increase the service life of the fuel cell engine.

[0005] The present invention provides a hydrogen-oxygen fuel cell engine control system based on water thermal management, comprising a fuel cell for generating electricity using hydrogen and oxygen, a hydrogen supply unit for supplying hydrogen to the fuel cell, an air supply unit for supplying oxygen to the fuel cell engine, and a purge unit for performing purge;

[0006] Among them, also include,

[0007] a diagnostic unit, the diagnostic unit being electrically connected to the fuel cell, the hydrogen supply unit, and the air supply unit; the diagnostic unit being configured to obtain status signals from the fuel cell, the hydrogen supply unit, and the air supply unit, and perform fault diagnosis based on the status signals;

[0008] A diagnostic control unit is electrically connected to the diagnostic unit, the hydrogen supply unit, and the air supply unit; the diagnostic control unit is used to obtain a diagnostic result of the diagnostic unit and adjust the hydrogen supply unit and the air supply unit according to the diagnostic result.

[0009] As described above, in the hydrogen-oxygen fuel cell engine control system based on water thermal management, optionally, the diagnosis result of the diagnosis unit includes: health status, cathode flooding, anode flooding and membrane dry fault.

[0010] The hydrogen-oxygen fuel cell engine control system based on water thermal management as described above, wherein the diagnostic unit includes:

[0011] Diagnostic controller;

[0012] a voltage sensor for detecting an output voltage of the fuel cell;

[0013] a first pressure sensor for detecting the air pressure at the air inlet of the fuel cell;

[0014] a second pressure sensor for detecting the air pressure at the air outlet of the fuel cell;

[0015] An internal resistance detection component for detecting the internal resistance of the fuel cell;

[0016] The diagnostic controller is electrically connected to the voltage sensor, the first pressure sensor and the second pressure sensor;

[0017] The diagnostic controller obtains the detection result of the voltage sensor and determines whether it is less than the set voltage threshold. If so, the diagnostic result is a healthy state; if not, the detection result of the internal resistance detection component is obtained, and it is determined whether the detection result of the internal resistance detection component is less than the set internal resistance value. If so, the fault is diagnosed as anode flooding or cathode flooding. If not, the diagnostic result is a membrane dry fault.

[0018] As described above, the hydrogen-oxygen fuel cell engine control system based on water thermal management, wherein the diagnostic unit further includes:

[0019] a first pressure sensor for detecting the air pressure at the air inlet of the fuel cell;

[0020] a second pressure sensor for detecting the air pressure at the air outlet of the fuel cell;

[0021] a third pressure sensor for detecting the pressure at the hydrogen inlet of the fuel cell;

[0022] a fourth pressure sensor for detecting the pressure at the hydrogen outlet of the fuel cell;

[0023] The diagnostic controller is further configured to, when diagnosing the fault as anode flooding or cathode flooding, obtain detection results of the third pressure sensor and the fourth pressure sensor, and estimate the anode pressure based on the detection results; and estimate the cathode pressure based on the detection results of the first pressure sensor and the second pressure sensor;

[0024] It is determined whether the anode pressure and the cathode pressure meet a first judgment condition. If yes, it is anode flooding; if not, it is cathode flooding.

[0025] As described above, the hydrogen-oxygen fuel cell engine control system based on water thermal management, wherein the first judgment condition is:

[0026]

[0027] Among them, a is the design coefficient, P yi is the cathode pressure, P ya is the anode pressure, ε is a constant coefficient ranging from 0.1 to 0.25.

[0028] As described above, the hydrogen-oxygen fuel cell engine control system based on water thermal management, wherein the diagnostic control unit further includes:

[0029] a first humidity sensor for detecting humidity at an air inlet of the fuel cell;

[0030] a second humidity sensor for detecting the humidity at the hydrogen inlet of the fuel cell;

[0031] A temperature sensor for detecting the internal temperature of the fuel cell;

[0032] The diagnostic control unit is electrically connected to the first humidity sensor, the second humidity sensor, the temperature sensor, the diagnostic controller, the first humidifier installed on the hydrogen supply unit, the second humidifier installed on the air supply unit, and the purge unit;

[0033] The diagnosis control unit is used to obtain the diagnosis result and control the first humidifier, the second humidifier and the purge unit to operate electrically according to the detection result, the detection result of the first humidity sensor and the detection result of the second humidity sensor.

[0034] The hydrogen-oxygen fuel cell engine control system based on water thermal management as described above, wherein the diagnostic control unit is used to control the fuel cell engine according to set parameters and programs when the diagnosis result is a healthy state;

[0035] The diagnostic control unit is configured to control the first humidifier and the second humidifier to increase the humidification amount when the diagnosis result is a membrane dry fault;

[0036] The diagnostic control unit is configured to adjust the first humidifier to reduce the humidity of the air when the diagnosis result is cathode flooding;

[0037] The diagnosis control unit is configured to adjust the second humidifier to reduce the humidity of the hydrogen when the diagnosis result is anode flooding.

[0038] As described above, the hydrogen-oxygen fuel cell engine control system based on water thermal management, wherein the diagnostic control unit is also electrically connected to the cooling system of the fuel cell engine, and the diagnostic control unit is also used to increase the coolant flow rate to reduce the temperature of the fuel cell when the diagnosis result is a membrane dry failure.

[0039] As described above, the hydrogen-oxygen fuel cell engine control system based on water thermal management, wherein the diagnostic control unit is further used to obtain the target power and determine the non-essential power in the target power when the diagnosis result is cathode flooding, and control the reduction of the non-essential power to reduce the current density.

[0040] As described above, the hydrogen-oxygen fuel cell engine control system based on hydrothermal management, wherein the diagnostic control unit is also electrically connected to the hydrogen supply system and the air supply system, and the diagnostic control unit is also used to control the reduction of hydrogen pressure and / or increase of air intake pressure to increase the anode pressure and / or reduce the cathode pressure when the diagnosis result is anode flooding.

[0041] Compared to existing technologies, the present invention uses a diagnostic unit to diagnose faults such as membrane dry-out, cathode flooding, and anode flooding in fuel cell engines. Based on the diagnostic results, the fuel cell engine is controlled to eliminate the faults and ensure that the proton exchange membrane always operates within an appropriate moisture content range. This ensures the reaction rate of hydrogen and oxygen and extends the service life of the fuel cell engine.

[0042] The present invention performs detailed diagnosis of membrane dry failure, cathode flooding, and anode flooding based on parameters such as output voltage, cathode voltage drop, anode voltage drop, and fuel cell internal resistance. Since cathode flooding and anode flooding are distinguished, the fault type is more accurate, which is sufficient for situation-specific fault elimination control.

[0043] The present invention eliminates the faults of the fuel cell engine in a targeted manner based on the diagnosis results, and can promptly eliminate cathode flooding, anode flooding and membrane dry faults, preventing the above three types of faults from evolving into serious faults. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is the overall structural diagram of the present invention;

[0045] Figure 2It is a flowchart of the steps for diagnosing fault types proposed by the present invention.

[0046] Description of reference numerals:

[0047] 1-Fuel cell, 2-Hydrogen supply unit, 3-Air supply unit, 4-Purge unit, 5-Diagnostic control unit, 6-Diagnostic controller, 7-Voltage sensor, 8-First pressure sensor, 9-Second pressure sensor, 10-Third pressure sensor, 11-Fourth pressure sensor, 12-First humidity sensor, 13-Second humidity sensor, 14-Temperature sensor, 15-First humidifier, 16-Second humidifier. DETAILED DESCRIPTION

[0048] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and are not to be construed as limiting the present invention.

[0049] Example 1,

[0050] Please refer to Figure 1 This embodiment discloses a hydrogen-oxygen fuel cell engine control system based on hydrothermal management, including a fuel cell 1 for generating electricity using hydrogen and oxygen, a hydrogen supply unit 2 for supplying hydrogen to the fuel cell 1, an air supply unit 3 for supplying oxygen to the fuel cell engine, and a purge unit 4 for purging. Since the fuel cell 1 hydrogen supply unit 2, the fuel cell 1 air supply unit 3, and the purge unit 4 are all prior art, their control systems are also existing and will not be described in this application. This embodiment adds a diagnostic unit and a diagnostic control unit 5, a connection relationship with related components, and a diagnostic method and a control method to the existing fuel cell engine.

[0051] Specifically, this embodiment adds a diagnostic unit and a diagnostic control unit 5. Specifically, the diagnostic unit is electrically connected to the fuel cell 1, the hydrogen supply unit 2, and the air supply unit 3; the diagnostic unit is configured to obtain status signals from the fuel cell 1, the hydrogen supply unit 2, and the air supply unit 3, and perform fault diagnosis based on the status signals. In a specific embodiment, the diagnostic unit performs real-time fault diagnosis while the fuel cell engine is operating, and is used to diagnose whether the fuel cell engine has a membrane dry-out fault, anode flooding, or cathode flooding.

[0052] The diagnostic control unit 5 is electrically connected to the diagnostic unit, the hydrogen supply unit 2, and the air supply unit 3; the diagnostic control unit 5 is configured to obtain the diagnostic results of the diagnostic unit and adjust the hydrogen supply unit 2 and the air supply unit 3 based on the diagnostic results. In specific implementations, the diagnostic unit's diagnostic results include healthy status, cathode flooding, anode flooding, and membrane dry failure. In implementation, healthy status refers to a situation where the voltage output by the fuel cell 1 is normal, i.e., the actual output voltage is substantially consistent with the target voltage. In this embodiment, only the identification and elimination of cathode flooding, anode flooding, and membrane dry failure types are addressed.

[0053] In practice, the diagnostic unit acquires status signals in real time and diagnoses the fault status of the fuel cell 1 based on the status signals. The diagnostic control unit 5 then obtains the diagnostic results and controls the hydrogen supply unit 2 and air supply unit 3 based on the results to eliminate the corresponding fault. This prevents the fault from further developing and causing serious damage to the fuel cell engine.

[0054] In the prior art, cathode flooding, anode flooding, and membrane dry-out failures all result in a reduction in the output voltage of the fuel cell 1. When troubleshooting, different types of faults require different troubleshooting methods, so accurate identification of the fault type is key to achieving the above results. Therefore, accurately diagnosing the fault type is a key issue to be addressed in this application. To this end, this embodiment accurately diagnoses the fault type using the following methods:

[0055] Specifically, the diagnosis unit includes a diagnosis controller 6 , a voltage sensor 7 , a first pressure sensor 8 , a second pressure sensor 9 and an internal resistance detection component.

[0056] The diagnosis controller 6 is used to obtain data required for diagnosis, including the output voltage of the fuel cell 1 , the pressure at the air inlet of the fuel cell 1 , the pressure at the air outlet of the fuel cell 1 , and the ohmic internal resistance of the fuel cell 1 .

[0057] Specifically, voltage sensor 7 is used to detect the output voltage of fuel cell 1 and is installed at the voltage output terminal of fuel cell 1. First pressure sensor 8 is used to detect the air pressure at the air inlet of fuel cell 1. Specifically, first pressure sensor 8 is installed at the air inlet of fuel cell 1, but can also be installed at the end of the air supply system. Second pressure sensor 9 is used to detect the air pressure at the air outlet of fuel cell 1. Specifically, second pressure sensor 9 is installed at the air outlet of fuel cell 1. Internal resistance detection component is used to detect the internal resistance of fuel cell 1. The internal resistance of fuel cell 1 is the ohmic internal resistance of fuel cell 1. During detection, the data obtained from EIS measurement can be used to perform curve fitting and parameter estimation on the PEMFC model to further obtain the ohmic impedance.

[0058] The diagnosis controller 6 is electrically connected to the voltage sensor 7 , the first pressure sensor 8 , and the second pressure sensor 9 , so that the diagnosis controller 6 can obtain detection results of the voltage sensor 7 , the first pressure sensor 8 , and the second pressure sensor 9 .

[0059] For details, please refer to Figure 2 , the steps for the diagnosis controller 6 to diagnose the fault type are:

[0060] S1 , the diagnosis controller 6 obtains the detection result of the voltage sensor 7 .

[0061] Step S2 determines whether the detection result of the voltage sensor 7 is less than the set voltage threshold. If so, the diagnosis is healthy; if not, proceed to step S3. In this embodiment, only three major faults that cause a voltage drop in the fuel cell 1 are diagnosed: anode flooding, cathode flooding, and membrane dry-out. In this step, the voltage of the fuel cell 1 is used to distinguish between a healthy state and a faulty state.

[0062] S3. Obtain the test result of the internal resistance detection component and determine whether the test result is less than a set internal resistance value. If so, the fault is diagnosed as a flooding fault, i.e., anode flooding or cathode flooding. If not, the fault is diagnosed as a membrane dry-out fault. In this step, the internal resistance detection component detects the ohmic internal resistance to distinguish between a flooding fault and a membrane dry-out fault.

[0063] The above steps can distinguish between a dry membrane fault and a flooding fault. For a dry membrane fault, the dry membrane fault can be eliminated directly according to the set method. However, flooding faults are divided into anode flooding and cathode flooding, and the anode flooding and cathode flooding are caused by different methods. Therefore, it is necessary to distinguish between anode flooding and cathode flooding.

[0064] In order to further distinguish anode flooding from cathode flooding, the present embodiment has also made the following improvements:

[0065] Specifically, the diagnosis unit further includes a first pressure sensor 8 , a second pressure sensor 9 , a third pressure sensor 10 and a fourth pressure sensor 11 .

[0066] The first pressure sensor 8 is used to detect the air pressure at the air inlet of the fuel cell 1; specifically, the first pressure sensor 8 is installed at the air inlet of the fuel cell 1. The second pressure sensor 9 is used to detect the air pressure at the air outlet of the fuel cell 1. In practice, the second pressure sensor 9 is installed at the air outlet of the fuel cell 1.

[0067] The third pressure sensor 10 is used to detect the pressure at the hydrogen inlet of the fuel cell 1. In implementation, the third pressure sensor 10 is installed at the hydrogen inlet of the fuel cell 1. The fourth pressure sensor 11 is used to detect the pressure at the hydrogen outlet of the fuel cell 1. The fourth pressure sensor 11 is installed at the hydrogen outlet of the fuel cell 1.

[0068] The diagnostic controller 6 is further configured to obtain detection results of the third pressure sensor 10 and the fourth pressure sensor 11 when diagnosing the fault as anode flooding or cathode flooding, and estimate the anode pressure based on the detection results. In specific implementation, the anode pressure is estimated in the following manner:

[0069]

[0070] Among them, P ya is the anode pressure; P ya1 is the detection result of the third pressure sensor 10, P ya2 is the detection result of the fourth pressure sensor 11.

[0071] estimating cathode pressure according to detection results of the first pressure sensor 8 and the second pressure sensor 9;

[0072]

[0073] Among them, P yi is the cathode pressure; P yi1 is the detection result of the first pressure sensor 8; P yi2 is the detection result of the second pressure sensor 9.

[0074] In a specific implementation, the process further includes S4, determining whether the anode pressure and the cathode pressure meet a first determination condition. If so, the anode is flooded; if not, the cathode is flooded.

[0075] That is, the relationship between the anode pressure and the cathode pressure is used to determine whether the cathode is flooded.

[0076] In specific implementation, the first judgment condition is:

[0077]

[0078] Among them, a is the design coefficient, P yi is the cathode pressure, P ya is the anode pressure, and ε is a constant coefficient with a value ranging from 0.1 to 0.25. In practice, the design coefficient is the ratio of the design cathode pressure to the design anode pressure. For example, if the cathode design pressure is 1.5 times the anode design pressure, then the value of a is 1.5. More specifically, the design coefficient refers to the ratio of the anode pressure to the cathode pressure set at the beginning of the design to utilize the pressure migration effect. If the design is unclear, the ratio of the anode pressure to the cathode pressure under normal conditions can be used as a reference to obtain the value used to characterize the design coefficient.

[0079] During implementation, in order to eliminate faults, the present embodiment has been improved as follows. Specifically, the diagnosis control unit 5 further includes a first humidity sensor 12 , a second humidity sensor 13 and a temperature sensor 14 .

[0080] The first humidity sensor 12 is used to detect the humidity at the air inlet of the fuel cell 1; the second humidity sensor 13 is used to detect the humidity at the hydrogen inlet of the fuel cell 1. The temperature sensor 14 is used to detect the internal temperature of the fuel cell 1. Specifically, the detection results of the first humidity sensor 12 and the second humidity sensor 13 are used to further determine the feasibility of the corresponding fault elimination method, so as to select the optimal elimination method.

[0081] Specifically, the diagnostic control unit 5 is electrically connected to the first humidity sensor 12, the second humidity sensor 13, the temperature sensor 14, the diagnostic controller 6, the first humidifier 15 installed on the hydrogen supply unit 2, the second humidifier 16 installed on the air supply unit 3, and the purge unit 4. Specifically, this embodiment eliminates the corresponding fault by controlling the first humidifier 15, the second humidifier 16, and the purge unit 4. In specific implementation, the purge of the anode can be achieved by the purge unit 4, while the purge of the cathode can be achieved by the air supply system, specifically by turning off the first humidifier to supply dry air to the cathode to achieve the purge of the anode.

[0082] The diagnostic control unit 5 is configured to obtain the diagnostic result and control the electrical operation of the first humidifier 15, the second humidifier 16, and the purge unit 4 based on the diagnostic result, the detection result of the first humidity sensor 12, and the detection result of the second humidity sensor 13. In practice, by controlling the humidification amount of the first humidifier 15 and the second humidifier 16, membrane dry-out faults and water-flooding faults can be eliminated.

[0083] Specifically, the diagnosis control unit 5 is used to control the fuel cell engine according to set parameters and programs when the diagnosis result is a healthy state; during implementation, the set parameters or programs refer to the existing control parameters and control algorithms of the fuel cell engine.

[0084] The diagnostic control unit 5 is configured to control the first humidifier 15 and the second humidifier 16 to increase the humidification capacity when the diagnosis result is a membrane dry-out fault. Specifically, when the diagnosis result is a membrane dry-out fault, the control unit 5 obtains the detection results of the first humidity sensor 12 and the second humidity sensor 13 and determines whether the humidification condition is met based on the detection results of the first humidity sensor 12 and the second humidity sensor 13. Specifically, the humidification condition is that the humidity is not greater than the maximum value of the corresponding humidity design range.

[0085] During implementation, membrane dry failure often occurs at the anode. Increasing the humidification capacity of the second humidifier 16 is beneficial to directly increase the water volume at the anode. Increasing the humidification capacity of the first humidifier 15 is beneficial to increase the water volume at the anode, so as to utilize osmosis to increase the movement of cathode to anode.

[0086] The diagnostic control unit 5 is configured to adjust the first humidifier 15 to reduce air humidity when the diagnosis result indicates cathode flooding. During implementation, the detection result of the first humidity sensor 12 is used to determine whether the humidity reduction condition is met, specifically, whether the detection result of the first humidity sensor 12 is not less than the minimum value of the set humidity range. If the humidity reduction condition is met, the humidification capacity of the first humidifier 15 is reduced to resolve the cathode flooding problem. If the humidity reduction condition is not met, there are two ways to eliminate cathode flooding. First, by obtaining a target power and determining the amount of non-essential power within the target power, the non-essential power is controlled to reduce the current density. Specifically, in a fuel cell vehicle 1, the power required to drive the vehicle is recorded as the required power, and the power required to charge the battery is recorded as the non-essential power. Other electrical components can be pre-set to either required or non-essential power based on actual conditions. This method reduces the current density, thereby reducing the electrical drag effect and the speed at which water flows from the anode to the cathode, thereby reducing or ultimately eliminating cathode flooding. Second, the purge system is controlled to perform a purge. To facilitate purging, a battery can be added to this system. During purging, the energy used, as well as the energy required to drive the vehicle, is provided by the battery. The battery can be charged when the fuel cell 1 is in a healthy state, or by plugging it in and charging it from an external power source.

[0087] The diagnostic control unit 5 is configured to adjust the second humidifier 16 to reduce the humidity of the hydrogen when the diagnosis result is anode flooding. In specific implementation, the detection result of the second humidity sensor 13 is first obtained to determine whether the detection result of the second humidity sensor 13 is greater than the minimum value of the hydrogen intake humidity range. If so, the humidification amount may be reduced; if not, the anode flooding is eliminated by controlling the pressure difference between the cathode and the anode. Specifically, the diagnostic control unit 5 is also electrically connected to the hydrogen supply system and the air supply system. When the diagnosis result is anode flooding, the diagnostic control unit 5 is further configured to control the reduction of hydrogen pressure and / or increase the air intake pressure to increase the anode pressure and / or reduce the cathode pressure. In this way, by controlling the pressure difference between the cathode and the anode, the pressure on both sides can be utilized to reduce or eliminate anode flooding.

[0088] Example 2

[0089] This embodiment is an improvement made on the basis of embodiment 1, and the similarities are not repeated here, and only the differences are described below.

[0090] Specifically, the diagnostic control unit 5 is also electrically connected to the cooling system of the fuel cell engine. The diagnostic control unit 5 is also used to increase the flow rate of the coolant to reduce the temperature of the fuel cell 1 when the diagnosis result is a membrane dry fault.

[0091] That is, when a membrane dry-out occurs, the humidification capacity of the first and second humidifiers 15, 16 is increased simultaneously with the coolant flow rate. Increasing the humidification capacity of the first and second humidifiers 15, 16 replenishes moisture in the fuel cell 1. Lowering the temperature of the fuel cell 1 significantly reduces moisture loss due to diffusion.

[0092] When a membrane dry-out occurs, the temperature of the proton exchange membrane rises, which, on the one hand, reduces the rate at which hydrogen ions pass through the membrane, resulting in a decrease in the amount of water produced at the cathode. On the other hand, the diffusion rate of water also increases rapidly. The above method not only replenishes water through the first humidifier 15 and the second humidifier 16, but also reduces the humidity of the proton exchange membrane, thereby reducing the diffusion rate of water. This can alleviate or even eliminate the membrane dry-out problem.

[0093] The diagnosis control unit 5 is further configured to control the purge system to perform purge when cathode flooding or anode flooding occurs and if purge has not been performed and the condition remains improved for a set period of time.

[0094] The above describes in detail the structure, features and effects of the present invention based on the embodiments shown in the drawings. The above is only a preferred embodiment of the present invention, but the scope of implementation of the present invention is not limited to what is shown in the drawings. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which do not exceed the spirit covered by the description and drawings, should be within the scope of protection of the present invention.

Claims

1. A hydrogen-oxygen fuel cell engine control system based on water thermal management, comprising a fuel cell for generating electricity using hydrogen and oxygen, a hydrogen supply unit for supplying hydrogen to the fuel cell, an air supply unit for supplying oxygen to the fuel cell, and a purge unit for performing purge; Its characteristics are: Also includes, a diagnostic unit, the diagnostic unit being electrically connected to the fuel cell, the hydrogen supply unit, and the air supply unit; the diagnostic unit being configured to obtain status signals from the fuel cell, the hydrogen supply unit, and the air supply unit, and perform fault diagnosis based on the status signals; a diagnostic control unit, the diagnostic control unit being electrically connected to the diagnostic unit, the hydrogen supply unit, and the air supply unit; the diagnostic control unit being configured to obtain a diagnostic result of the diagnostic unit and to adjust the hydrogen supply unit and the air supply unit according to the diagnostic result; The diagnostic results of the diagnostic unit include: health status, cathode flooding, anode flooding and membrane dry fault; The diagnostic unit comprises: Diagnostic controller; a voltage sensor for detecting an output voltage of the fuel cell; An internal resistance detection component for detecting the internal resistance of the fuel cell; The diagnostic controller is electrically connected to the voltage sensor and the internal resistance detection component; When the diagnosis result is not a healthy state, the diagnosis controller obtains the detection result of the internal resistance detection component and determines whether the detection result of the internal resistance detection component is less than a set internal resistance value. If so, the fault is diagnosed as anode flooding or cathode flooding; if not, the diagnosis result is a membrane dry fault. The diagnostic unit further comprises, a first pressure sensor for detecting the air pressure at the air inlet of the fuel cell; a second pressure sensor for detecting the air pressure at the air outlet of the fuel cell; a third pressure sensor for detecting the pressure at the hydrogen inlet of the fuel cell; a fourth pressure sensor for detecting the pressure at the hydrogen outlet of the fuel cell; The diagnostic controller is further configured to, when diagnosing the fault as anode flooding or cathode flooding, obtain detection results of the third pressure sensor and the fourth pressure sensor, and estimate the anode pressure based on the detection results; and estimate the cathode pressure based on the detection results of the first pressure sensor and the second pressure sensor; According to whether the anode pressure and the cathode pressure meet the first judgment condition, if yes, it is anode flooding, if not, it is cathode flooding; The first judgment condition is: in, is the design coefficient, which is the ratio of the design cathode pressure to the design anode pressure. is the cathode pressure, is the anode pressure, is a constant coefficient ranging from 0.1 to 0.

25.

2. The hydrogen-oxygen fuel cell engine control system based on water thermal management according to claim 1, characterized in that: The diagnostic control unit further includes: a first humidity sensor for detecting humidity at an air inlet of the fuel cell; a second humidity sensor for detecting the humidity at the hydrogen inlet of the fuel cell; A temperature sensor for detecting the internal temperature of the fuel cell; The diagnostic control unit is electrically connected to the first humidity sensor, the second humidity sensor, the temperature sensor, the diagnostic controller, the first humidifier installed on the hydrogen supply unit, the second humidifier installed on the air supply unit, and the purge unit; The diagnosis control unit is used to obtain the diagnosis result and control the first humidifier, the second humidifier and the purge unit to operate electrically according to the diagnosis result, the detection result of the first humidity sensor and the detection result of the second humidity sensor.

3. The hydrogen-oxygen fuel cell engine control system based on water thermal management according to claim 2, characterized in that: The diagnostic control unit is used to control the fuel cell engine according to set parameters and programs when the diagnosis result is a healthy state; The diagnostic control unit is configured to control the first humidifier and the second humidifier to increase the humidification amount when the diagnosis result is a membrane dry fault; The diagnostic control unit is configured to adjust the first humidifier to reduce the humidity of the air when the diagnosis result is cathode flooding; The diagnosis control unit is configured to adjust the second humidifier to reduce the humidity of the hydrogen when the diagnosis result is anode flooding.

4. The hydrogen-oxygen fuel cell engine control system based on water thermal management according to claim 2, characterized in that: The diagnostic control unit is also electrically connected to the cooling system of the fuel cell engine. The diagnostic control unit is also used to increase the flow rate of the coolant to reduce the temperature of the fuel cell when the diagnosis result is a membrane dry fault.

5. The hydrogen-oxygen fuel cell engine control system based on water thermal management according to claim 4, characterized in that: The diagnosis control unit is further configured to obtain target power and determine unnecessary power in the target power when the diagnosis result is cathode flooding, and control the reduction of unnecessary power to reduce current density.

6. The hydrogen-oxygen fuel cell engine control system based on water thermal management according to claim 5, characterized in that: The diagnostic control unit is also electrically connected to the hydrogen supply unit and the supply unit. The diagnostic control unit is also used to control the reduction of hydrogen intake pressure and / or increase of air intake pressure to increase anode pressure and / or reduce cathode pressure when the diagnosis result is anode flooding.

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