Cathode water blocking prevention system of hydrogen fuel cell and control method

Abstract

The invention provides a hydrogen fuel cell cathode water blockage prevention system and a control method. The system comprises a fuel cell system control unit FCU, a galvanic pile inspection CVM, an air compressor and a cooling fan, wherein the electric pile inspection CVM sends a collected voltage signal to the fuel cell system control unit FCU, and the fuel cell system control unit FCU is used for determining whether the average single cell voltage is greater than the minimum single cell voltage and exceeds a threshold value; when it is determined that the average battery monomer voltage is larger than the minimum battery monomer voltage and exceeds a threshold value, the rotating speed of the air compressor is controlled to be increased; and the target in-pile temperature of the cooling liquid is increased, and the rotating speed of the cooling fan is reduced. According to the invention, the water blocking condition of the cathode side of the fuel cell can be identified in time, and the residual water on the cathode side can be rapidly discharged by increasing the air flow or increasing the temperature, so that emergency shutdown caused by the water blocking of the cathode side is prevented, and the stability of a hydrogen fuel cell system is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of hydrogen fuel cells, and in particular to a hydrogen fuel cell cathode water blocking prevention system and a control method. Background Art

[0002] A hydrogen fuel cell is a power generation device that directly converts the chemical energy of hydrogen and oxygen into electrical energy. Its basic principle is based on the redox reaction of anode hydrogen and cathode oxygen at the electrodes. Hydrogen is oxidized into hydrogen ions and electrons at the anode. The electrons flow to the cathode through an external circuit, while the hydrogen ions reach the cathode through the electrolyte membrane. At the cathode, hydrogen ions combine with oxygen to form water, while releasing a large amount of heat energy.

[0003] During the normal operation of a hydrogen fuel cell, a large amount of water will be generated on the cathode side. If the water attached to the cathode is not discharged from the system in time, it will cause cathode water blockage. If the cathode water blockage is not identified in time and effective measures are not taken to remove the residual water, the voltage of some cells of the hydrogen fuel cell will be low. In severe cases, it will cause the system to shut down urgently, posing a great safety hazard. Summary of the invention

[0004] A technical problem to be solved by the present disclosure is that if water blockage at the cathode of a hydrogen fuel cell is not promptly identified and effective measures are not taken to discharge the residual water, the voltage of some cells of the hydrogen fuel cell will be low, and in severe cases, the system will be shut down urgently.

[0005] In order to solve the above technical problems, the first aspect of the embodiment of the present disclosure provides a hydrogen fuel cell cathode water plugging prevention system. The system includes: a fuel cell system control unit FCU, a stack inspection CVM, an air compressor, and a cooling fan; wherein the stack inspection CVM is used to collect the voltage signal of the fuel cell monomer and send the collected voltage signal to the fuel cell system control unit FCU, and the fuel cell system control unit FCU is used to perform the following operations: according to the collected voltage signal, determine whether the average battery cell voltage is greater than the minimum battery cell voltage by more than a threshold value; when it is determined that the average battery cell voltage is greater than the minimum battery cell voltage by more than a threshold value, perform at least one of the following operations: control to increase the speed of the air compressor; and increase the target stack temperature of the coolant, and reduce the speed of the cooling fan.

[0006] The present invention discloses a hydrogen fuel cell cathode water blockage prevention system, which can timely identify the cathode water blockage state and discharge the residual water in time by increasing the air flow or raising the temperature, thereby reducing the occurrence of emergency shutdown caused by water blockage during operation and improving the stability and reliability of the hydrogen fuel cell system operation.

[0007] In some embodiments, after controlling to increase the speed of the air compressor, the fuel cell system control unit FCU determines whether the average battery cell voltage is greater than the minimum battery cell voltage by more than a threshold value. If not, the current operating state of the air compressor and the cooling fan is maintained.

[0008] In some embodiments, after controlling to increase the speed of the air compressor, the fuel cell system control unit FCU determines whether the average battery cell voltage is greater than the minimum battery cell voltage by more than a threshold value. If so, the target coolant inlet temperature is increased and the speed of the cooling fan is reduced.

[0009] In some embodiments, the system further includes: a coolant inlet temperature sensor, which is used to collect the current coolant inlet temperature signal and send the collected temperature signal to the fuel cell system control unit FCU. After increasing the coolant target inlet temperature and reducing the speed of the cooling fan, the fuel cell system control unit FCU determines whether the absolute value of the difference between the actual coolant inlet temperature and the coolant target inlet temperature is less than a threshold value. If not, the speed of the cooling fan continues to be reduced.

[0010] In some embodiments, the fuel cell system control unit FCU waits for a preset time before determining whether the absolute value of the difference between the actual coolant inlet temperature and the coolant inlet temperature is less than a threshold.

[0011] In some embodiments, the fuel cell system control unit FCU continuously collects voltage signals and performs the above operations when it determines that the average battery cell voltage is not greater than the minimum battery cell voltage by more than a threshold and does not receive a shutdown command sent from the vehicle control unit VCU.

[0012] A second aspect of an embodiment of the present disclosure provides a control method for a hydrogen fuel cell cathode water plugging prevention system, the system comprising an air compressor and a cooling fan, the method comprising: collecting voltage signals of fuel cell cells, determining whether an average battery cell voltage is greater than a minimum battery cell voltage by more than a threshold value; when it is determined that the average battery cell voltage is greater than a minimum battery cell voltage by a threshold value, performing at least one of the following operations: controlling to increase the speed of the air compressor; and increasing the target stack inlet temperature of the coolant, and reducing the speed of the cooling fan.

[0013] In some embodiments, after the speed of the air compressor is increased, it is determined whether the average battery cell voltage is greater than the lowest battery cell voltage by more than a threshold value. If not, the current operating states of the air compressor and the cooling fan are maintained.

[0014] In some embodiments, after the air compressor speed is increased, it is determined whether the average battery cell voltage is greater than the lowest battery cell voltage by more than a threshold. If so, the target coolant inlet temperature is increased and the speed of the cooling fan is reduced.

[0015] In some embodiments, the method further includes: collecting a current coolant inlet temperature signal; after increasing the coolant inlet target temperature and reducing the speed of the cooling fan, determining whether the absolute value of the difference between the coolant actual inlet temperature and the coolant target inlet temperature is less than a threshold value; if not, continuing to reduce the speed of the cooling fan.

[0016] In some embodiments, before determining whether the absolute value of the difference between the actual coolant entering the stack temperature and the target coolant entering the stack temperature is less than a threshold, a preset time is waited.

[0017] In some embodiments, the method is continuously executed when it is determined that the average battery cell voltage is not greater than the lowest battery cell voltage by more than a threshold and no shutdown instruction is received from the vehicle control unit VCU.

[0018] Through the above technical scheme, the hydrogen fuel cell cathode water blockage prevention system provided by the present invention determines whether the average battery cell voltage is greater than the minimum battery cell voltage by more than a threshold value based on the collected voltage signal. When the voltage difference is large, it means that water blockage has occurred. The air compressor speed is increased and / or the cooling fan speed is reduced to increase the air flow or increase the temperature, so that the water on the cathode side can be quickly discharged from the system, solving the water blockage problem, avoiding the emergency shutdown caused by water blockage during the operation of the fuel cell, and improving the stability of the fuel cell system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 It is a structural schematic diagram of a hydrogen fuel cell cathode water plugging prevention system disclosed in an embodiment of the present disclosure;

[0021] Figure 2 It is a flow chart of a method for controlling a hydrogen fuel cell cathode water blockage prevention system disclosed in an embodiment of the present disclosure.

[0022] Description of reference numerals:

[0023] 1. Fuel cell system control unit FCU; 2. Stack inspection CVM; 3. Air compressor; 4. Cooling fan; 5. Coolant inlet temperature sensor; 6. Vehicle control unit VCU. DETAILED DESCRIPTION

[0024] The following is a further detailed description of the embodiments of the present disclosure in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present disclosure, but cannot be used to limit the scope of the present disclosure. The present disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

[0025] The present disclosure provides these embodiments to make the present disclosure thorough and complete, and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the parts and steps, the composition of the materials, the numerical expressions and the numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary, and not as limiting.

[0026] It should be noted that, in the description of the present disclosure, unless otherwise specified, the meaning of "multiple" is greater than or equal to two; the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0027] In addition, the words "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. "Vertical" does not mean vertical in the strict sense, but is within the tolerance range. "Parallel" does not mean parallel in the strict sense, but is within the tolerance range. "Include" or "comprising" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements.

[0028] It should also be noted that in the description of the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device.

[0029] All terms used in the present disclosure have the same meanings as those understood by those of ordinary skill in the art to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, for example, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined as such herein.

[0030] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0031] Example

[0032] Figure 1 Schematic diagram of the structure of the hydrogen fuel cell cathode water blocking prevention system disclosed in the embodiment of the present disclosure. Figure 1 As shown, the system includes: a fuel cell system control unit FCU1, a stack inspection CVM2, an air compressor 3, and a cooling fan 4; wherein the stack inspection CVM2 is used to collect voltage signals of fuel cell cells, and send the collected voltage signals to the fuel cell system control unit FCU1, and the fuel cell system control unit FCU1 is used to perform the following operations: determine whether the average battery cell voltage is greater than the minimum battery cell voltage by more than a threshold value based on the collected voltage signals; when it is determined that the average battery cell voltage is greater than the minimum battery cell voltage by more than a threshold value, perform at least one of the following operations: control to increase the rotation speed of the air compressor 3; and increase the target stack inlet temperature of the coolant, and reduce the rotation speed of the cooling fan 4.

[0033] Specifically, the present disclosure uses the stack inspection CVM2 to collect the voltage signal of the fuel cell monomer, and this voltage signal includes the average cell voltage and the minimum cell voltage of the fuel cell monomer. The collected voltage signal is sent to the fuel cell system control unit FCU1, and the fuel cell system control unit FCU1 calculates the difference between the average cell voltage and the minimum cell voltage of the fuel cell monomer. By judging whether the average cell voltage of the fuel cell monomer is greater than the minimum cell voltage by a threshold value, it is determined whether water blockage occurs on the cathode side of the fuel cell. When it exceeds a set threshold value, it indicates that water blockage has occurred. After timely identifying the water blockage state, the speed of the air compressor 3 is immediately increased and / or the target stack temperature of the coolant is increased to reduce the speed of the cooling fan 4, so as to accelerate the discharge of water by increasing the air flow or raising the temperature, and prevent the emergency shutdown caused by water blockage, thereby achieving the purpose of timely identifying the water blockage state and accelerating the discharge of residual water, and ensuring the stability of the fuel cell system operation.

[0034] In some embodiments, after controlling to increase the speed of the air compressor 3, the fuel cell system control unit FCU1 determines whether the average battery cell voltage is greater than the minimum battery cell voltage by more than a threshold value. If not, the current operating state of the air compressor 3 and the cooling fan 4 is maintained.

[0035] In some embodiments, after controlling to increase the speed of the air compressor 3 , the fuel cell system control unit FCU1 determines whether the average battery cell voltage is greater than the minimum battery cell voltage by more than a threshold value. If so, the target stack temperature of the coolant is increased and the speed of the cooling fan 4 is reduced.

[0036] Specifically, whether water blockage occurs on the cathode side is determined by judging whether the voltage difference between the average battery cell voltage and the lowest battery cell voltage exceeds a threshold. The setting of this threshold is determined by the characteristics of the fuel cell stack itself, and technicians in this field can set different thresholds according to actual applications.

[0037] In some embodiments, the system further includes: a coolant inlet temperature sensor 5, which is used to collect the current coolant inlet temperature signal and send the collected temperature signal to the fuel cell system control unit FCU1. After increasing the coolant target inlet temperature and reducing the rotation speed of the cooling fan 4, the fuel cell system control unit FCU1 determines whether the absolute value of the difference between the actual coolant inlet temperature and the coolant target inlet temperature is less than a threshold value. If not, the rotation speed of the cooling fan 4 continues to be reduced.

[0038] In some embodiments, the fuel cell system control unit FCU1 waits for a preset time before determining whether the absolute value of the difference between the actual coolant inlet temperature and the coolant inlet temperature is less than a threshold.

[0039] Specifically, after reducing the speed of the cooling fan 4, after waiting for a preset time, it is determined whether the absolute value of the difference between the actual coolant inlet temperature and the coolant target inlet temperature is less than a threshold value, which is used for the recovery time of the stack after taking the cooling fan 4 speed reduction measure. After waiting for a preset time, the state of the stack is relatively stable, and it is more accurate to re-judge the state of the stack at this time. The specific value of this preset time is determined by experiment.

[0040] In some embodiments, the fuel cell system control unit FCU1 continuously collects voltage signals and performs the above operations when it determines that the average battery cell voltage is not greater than the minimum battery cell voltage by more than a threshold and does not receive a shutdown command sent from the vehicle control unit VCU6.

[0041] A second aspect of the disclosed embodiment provides a control method for a hydrogen fuel cell cathode water plugging prevention system, the system comprising an air compressor 3 and a cooling fan 4, the control method comprising: collecting voltage signals of fuel cell cells, determining whether an average cell voltage is greater than a minimum cell voltage by more than a threshold value; when it is determined that the average cell voltage is greater than a minimum cell voltage by a threshold value, performing at least one of the following operations: controlling to increase the rotation speed of the air compressor 3; and increasing the target stack inlet temperature of the coolant, and reducing the rotation speed of the cooling fan 4.

[0042] In some embodiments, after the speed of the air compressor 3 is increased, it is determined whether the average battery cell voltage is greater than the minimum battery cell voltage by more than a threshold value. If not, the current operating state of the air compressor 3 and the cooling fan 4 is maintained.

[0043] In some embodiments, after the speed of the air compressor 3 is increased, it is determined whether the average battery cell voltage is greater than the minimum battery cell voltage by a threshold value. If so, the target stack temperature of the coolant is increased and the speed of the cooling fan 4 is reduced.

[0044] In some embodiments, the method further includes: collecting a current coolant inlet temperature signal; after increasing the coolant inlet target temperature and reducing the rotation speed of the cooling fan 4, determining whether the absolute value of the difference between the actual coolant inlet temperature and the coolant inlet target temperature is less than a threshold value; if not, continuing to reduce the rotation speed of the cooling fan 4.

[0045] In some embodiments, before determining whether the absolute value of the difference between the actual coolant entering the stack temperature and the target coolant entering the stack temperature is less than a threshold, a preset time is waited.

[0046] In some embodiments, when it is determined that the average battery cell voltage is not greater than the lowest battery cell voltage by more than a threshold and no shutdown instruction is received from the vehicle control unit VCU6 , the method is continuously executed.

[0047] Figure 2 1 is a flow chart of a method for controlling a hydrogen fuel cell cathode water blocking prevention system disclosed in an embodiment of the present disclosure. Figure 2 As shown, the process of the hydrogen fuel cell cathode water blockage prevention system control method disclosed in the embodiment of the present disclosure is explained.

[0048] Step 1: Connect low voltage to the system;

[0049] Step 2: The vehicle control unit VCU6 sends a power-on command to the fuel cell system control unit FCU1;

[0050] Step 3: The fuel cell system control unit FCU1 collects the voltage signal of the fuel cell monomer sent by the stack inspection CVM2;

[0051] Step 4: The fuel cell system control unit FCU1 determines whether the average battery cell voltage is greater than the minimum battery cell voltage by more than 50mV. If yes, it goes to step 5, otherwise it goes to step 3;

[0052] Step 5: The fuel cell system control unit FCU1 controls the speed of the air compressor 3 to increase by 2000 rpm and waits for 10 seconds;

[0053] Step 6: Determine whether the average battery cell voltage is greater than the lowest battery cell voltage by more than 50mV, if yes, proceed to step 7, otherwise proceed to step 8;

[0054] Step 7: The fuel cell system control unit FCU1 increases the target stack temperature of the coolant by 5°C;

[0055] Step 8: The air compressor 3 and the cooling fan 4 maintain the current operating state;

[0056] Step 9: Determine whether the vehicle control unit VCU6 sends a shutdown command to the fuel cell system control unit FCU1, if yes, go to step 17, otherwise go to step 3;

[0057] Step 10: The fuel cell system control unit FCU1 controls the speed of the cooling fan 4 to decrease by 2%;

[0058] Step 11: Keep the current running state and wait for 15 seconds;

[0059] Step 12: Determine whether the absolute value of the difference between the actual coolant inlet temperature and the coolant inlet temperature is less than 1°C. If yes, proceed to step 13; otherwise, proceed to step 10;

[0060] Step 13: Keep the current running state and wait for 20 seconds;

[0061] Step 14: Determine whether the average battery cell voltage is greater than the minimum battery cell voltage by more than 50mV, if so, the system shuts down, otherwise proceed to step 15;

[0062] Step 15: Determine whether the vehicle control unit VCU6 sends a shutdown command to the fuel cell system control unit FCU1, if yes, go to step 16, otherwise go to step 3;

[0063] Step 16: Shut down the system.

[0064] It is understandable that the values ​​of the voltage threshold, rotation speed, increased temperature and waiting time set in the above steps are only for illustrative purposes and are not limiting. Those skilled in the art can set different values ​​according to actual needs.

[0065] So far, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0066] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict.

Claims

1. A hydrogen fuel cell cathode water blocking prevention system, characterized in that: The system comprises: A fuel cell system control unit FCU (1), a stack inspection CVM (2), an air compressor (3), and a cooling fan (4); The stack inspection CVM (2) is used to collect voltage signals of fuel cell monomers and send the collected voltage signals to the fuel cell system control unit FCU (1). The fuel cell system control unit FCU (1) is used to perform the following operations: Determining, based on the collected voltage signal, whether the average battery cell voltage is greater than the lowest battery cell voltage by more than a threshold value; If it is determined that the average battery cell voltage is greater than the lowest battery cell voltage by more than a threshold, at least one of the following operations is performed: Controlling and increasing the rotation speed of the air compressor (3); and The target inlet temperature of the coolant is increased, and the rotation speed of the cooling fan (4) is reduced.

2. The system according to claim 1, characterized in that After controlling the increase of the rotation speed of the air compressor (3), the fuel cell system control unit FCU (1) determines whether the average battery cell voltage is greater than the minimum battery cell voltage by more than a threshold value, and if not, maintains the current operating state of the air compressor (3) and the cooling fan (4).

3. The system according to claim 1, characterized in that After controlling the increase of the rotation speed of the air compressor, the fuel cell system control unit FCU (1) determines whether the average battery cell voltage is greater than the minimum battery cell voltage by more than a threshold value. If so, the target stack inlet temperature of the coolant is increased and the rotation speed of the cooling fan (4) is reduced.

4. The system according to any one of claims 1 to 3, characterized in that: The system also includes: A coolant inlet temperature sensor (5) is used to collect a current coolant inlet temperature signal and send the collected temperature signal to the fuel cell system control unit FCU (1). After increasing the target inlet temperature of the coolant and reducing the rotation speed of the cooling fan (4), the fuel cell system control unit FCU (1) determines whether the absolute value of the difference between the actual inlet temperature of the coolant and the target inlet temperature of the coolant is less than a threshold value, and if not, continues to reduce the rotation speed of the cooling fan (4).

5. The system according to claim 4, characterized in that The fuel cell system control unit FCU (1) waits for a preset time before determining whether the absolute value of the difference between the actual coolant inlet temperature and the coolant inlet temperature is less than a threshold.

6. The system according to claim 1, characterized in that The fuel cell system control unit FCU (1) continuously collects the voltage signal and performs the above operation when it determines that the average battery cell voltage is not greater than the lowest battery cell voltage by more than a threshold value and does not receive a shutdown command sent by the vehicle control unit VCU (6).

7. A control method for a hydrogen fuel cell cathode water blocking prevention system, characterized in that: The system comprises an air compressor (3) and a cooling fan (4), and the control method comprises: Collecting voltage signals of fuel cell cells to determine whether the average cell voltage is greater than the minimum cell voltage by a threshold value; In the event that it is determined that the average battery cell voltage is greater than a threshold value of the lowest battery cell voltage, at least one of the following operations is performed: Controlling and increasing the rotation speed of the air compressor (3); and The target inlet temperature of the coolant is increased, and the rotation speed of the cooling fan (4) is reduced.

8. The control method according to claim 7, characterized in that: After the speed of the air compressor (3) is increased, it is determined whether the average battery cell voltage is greater than the minimum battery cell voltage by more than a threshold value; if not, the current operating state of the air compressor (3) and the cooling fan (4) is maintained.

9. The control method according to claim 7, characterized in that: After the speed of the air compressor (3) is increased, it is determined whether the average battery cell voltage is greater than the minimum battery cell voltage by more than a threshold value. If so, the target stack temperature of the coolant is increased and the speed of the cooling fan (4) is reduced.

10. The control method according to any one of claims 7 to 9, characterized in that: The method further includes: Collect the temperature signal of the current coolant entering the pile; After increasing the target inlet temperature of the coolant and reducing the rotation speed of the cooling fan (4), it is determined whether the absolute value of the difference between the actual inlet temperature of the coolant and the target inlet temperature of the coolant is less than a threshold value; if not, the rotation speed of the cooling fan (4) is further reduced.

11. The control method according to claim 10, characterized in that: Before determining whether the absolute value of the difference between the actual coolant entering the stack temperature and the coolant target entering the stack temperature is less than a threshold, a preset time is waited.

12. The control method according to claim 7, characterized in that: When it is determined that the average battery cell voltage is not greater than the lowest battery cell voltage by more than a threshold and no shutdown command is received from the vehicle control unit VCU (6), the method is continuously executed.

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