Fuel cell system water balance monitoring method and device

Abstract

The present invention provides a method and device for monitoring water balance of a fuel cell system. The method for monitoring water balance of a fuel cell system includes: obtaining the initial calibration value of tail water discharge under different working currents of the fuel cell during the test of the polarization curve of the fuel cell engine; recording the initial time t1 of the fuel cell and the time t2 when the tail water discharge of the fuel cell reaches the set position during the operation of the fuel cell, and recording the working current of the fuel cell between time t1 and time t2; obtaining the initial calibration value of tail water discharge corresponding to the working current based on the working current of the fuel cell between time t1 and time t2; obtaining the calibrated generated water volume V0 based on time t1, time t2 and the initial calibration value of tail water discharge corresponding to the working current; obtaining the actual generated water volume V1 of the fuel cell from time t1 to time t2 based on the set position; obtaining the monitoring result based on the comparison result of the actual generated water volume V1 and the calibrated generated water volume V0. The purpose of accurately judging the water balance state is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of new energy technology, and in particular relates to a method and device for monitoring water balance of a fuel cell system. Background Art

[0002] During the operation of the fuel cell, water is generated through reaction on the cathode side. Part of the water enters the anode through diffusion, and part is carried away by the gas. The internal water balance is relatively complex. If there is a problem with the water balance, such as membrane drying, flooding, etc., it will seriously affect the performance and life of the fuel cell.

[0003] In the existing technology, water balance is monitored by air-side pressure drop or AC impedance. However, air pressure drop can identify water flooding but cannot identify membrane dryness. High-frequency AC impedance can identify membrane dryness but cannot identify water flooding. Low-frequency AC impedance cannot accurately identify water flooding at present. In addition, there are some reasons that may lead to misjudgment of water balance in the existing water balance monitoring technology, such as the adsorption of catalyst sulfonate groups leading to obstruction of oxygen transmission, which may lead to misjudgment of water balance.

[0004] In summary, the prior art has the problem of being unable to accurately judge both membrane drying and water flooding. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a method and device for monitoring water balance of a fuel cell system, which at least partially solves the problem existing in the prior art that it is impossible to accurately judge both membrane drying and water flooding.

[0006] In a first aspect, an embodiment of the present disclosure provides a method for monitoring water balance of a fuel cell system, comprising:

[0007] During the fuel cell engine polarization curve test, the initial calibration value of tail water discharge under different working currents of the fuel cell is obtained;

[0008] During the operation of the fuel cell, record the initial time t1 of the fuel cell and the time t2 when the tail water of the fuel cell reaches the set position, and record the working current of the fuel cell between time t1 and time t2;

[0009] Based on the working current of the fuel cell between time t1 and time t2, an initial calibration value of tail water discharge corresponding to the working current is obtained;

[0010] The calibrated generated water volume V0 is obtained based on the initial calibration value of the tail water discharge at time t1, time t2 and the corresponding working current;

[0011] Based on the set position, the actual amount of water V1 generated by the fuel cell from time t1 to time t2 is obtained;

[0012] The monitoring result is obtained based on the comparison result of the actual generated water volume V1 and the calibrated generated water volume V0.

[0013] Optionally, during the fuel cell engine polarization curve test, obtaining the initial calibration value of the tail water under different operating currents of the fuel cell includes:

[0014] During the fuel cell engine polarization curve test, for each current point, tail water is collected after the voltage stabilizes, and the collected water volume and collection time are recorded. The tail water generation rate is obtained based on the collected water volume and collection time, and the tail water generation rate is used as the initial calibration value of the tail water.

[0015] Optionally, obtaining the tailwater generation rate based on the collected water volume and the collection time includes:

[0016] The tailwater generation rate is obtained by dividing the collected water volume by the collection time.

[0017] Optionally, in the collected tail water, the tail water is condensed water in the cathode tail gas and / or condensed water in the anode tail gas.

[0018] Optionally, during the operation of the fuel cell, the initial time t1 of the fuel cell and the time t2 when the tail water of the fuel cell reaches a set position are recorded, and the set position is obtained based on a liquid level sensor arranged in a real-time collection device for the tail water.

[0019] Optionally, during the operation of the fuel cell, recording the initial time t1 of the fuel cell and the time t2 when the tail water of the fuel cell reaches the set position includes:

[0020] When the tail drainage in the tail drainage real-time collection device reaches the set position, the tail drainage in the tail drainage real-time collection device is discharged.

[0021] Optionally, the monitoring result is obtained based on the comparison result of the actually generated water volume V1 and the calibrated generated water volume V0, including:

[0022] When V1 is greater than V0, it is flooded, and when V1 is less than V0, it is dry.

[0023] Optionally, in the monitoring result obtained based on the comparison result of the actually generated water volume V1 and the calibrated generated water volume V0, the error of the calibrated generated water volume V0 is set to 10%.

[0024] Optionally, the monitoring result obtained based on the comparison result of the actually generated water volume V1 and the calibrated generated water volume V0 includes:

[0025] If 0.9V0 < V1 < 1.1V0, the water balance is in a normal state. If V1 > 1.1V0, it is waterlogging, and the air flow is increased for purging to drain the water inside the fuel cell stack. If V1 < 0.9V0, it is membrane dryness, and the temperature of the fuel cell stack is reduced and the air humidity is increased.

[0026] In a second aspect, an embodiment of the present disclosure further provides a fuel cell system water balance monitoring device, including:

[0027] A calibration module, configured to obtain an initial calibration value of the tail drain water at different operating currents of the fuel cell during the polarization curve test of the fuel cell engine;

[0028] A recording module, configured to record the initial time t1 of the fuel cell and the time t2 when the tail drain water of the fuel cell reaches a set position during the operation of the fuel cell, and record the operating current of the fuel cell between the time t1 and the time t2;

[0029] A calibration value acquisition module, configured to obtain the initial calibration value of the tail drain water corresponding to the operating current based on the operating current of the fuel cell between the time t1 and the time t2;

[0030] A calculation module, configured to obtain the calibrated generated water volume V0 based on the time t1, the time t2, and the initial calibration value of the tail drain water corresponding to the operating current;

[0031] An actual water volume module, configured to obtain the actually generated water volume V1 of the fuel cell from time t1 to time t2 based on the set position;

[0032] A monitoring module, configured to obtain a monitoring result based on the comparison result between the actually generated water volume V1 and the calibrated generated water volume V0.

[0033] The fuel cell system water balance monitoring method and device provided by the present invention. The fuel cell system water balance monitoring method detects the water balance by comparing the calibrated generated water volume and the actually generated water volume of the tail drain water, can monitor both membrane dryness and waterlogging, and has accurate judgment, so as to achieve the purpose of accurately judging the water balance state. Description of the Drawings

[0034] By describing the exemplary embodiments of the present disclosure in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present disclosure will become more obvious. Among them, in the exemplary embodiments of the present disclosure, the same reference numerals generally represent the same components.

[0035] Figure 1 It is a flowchart of the fuel cell system water balance monitoring method provided by the embodiment of the present disclosure;

[0036] Figure 2 It is a schematic structural diagram of the tail drain water real-time collection device provided by the embodiment of the present disclosure;

[0037] Figure 3 A control logic diagram for monitoring a fuel cell system provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0038] The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0039] It should be clear that the following embodiments of the present disclosure are described by specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. The present disclosure 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 disclosure. It should be noted that the following embodiments and features in the embodiments can be combined with each other in the absence of conflict. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present disclosure.

[0040] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein may be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present disclosure, it should be understood by those skilled in the art that an aspect described herein may be implemented independently of any other aspect, and two or more of these aspects may be combined in various ways. For example, any number of aspects described herein may be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein may be used to implement this device and / or practice this method.

[0041] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present disclosure. The illustrations only show components related to the present disclosure rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0042] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0043] The fuel cell or fuel cell system in this embodiment refers to a proton exchange membrane fuel cell system.

[0044] like Figure 1 As shown, this embodiment discloses a method for monitoring water balance of a fuel cell system, including:

[0045] Step S101: during the fuel cell engine polarization curve test, obtaining the tail water initial calibration value under different working currents of the fuel cell;

[0046] When the fuel cell is working, its working current changes according to the working conditions, so it is necessary to obtain the initial calibration value of the tail water discharge under different working currents, that is, the initial calibration value of the tail water discharge when the working current is I1, I2, I3, etc.

[0047] Optionally, during the fuel cell engine polarization curve test, the initial calibration value of the tail water under different working currents of the fuel cell is obtained, including:

[0048] During the fuel cell engine polarization curve test, for each current point, tail water is collected after the voltage stabilizes, and the collected water volume and collection time are recorded. The tail water generation rate is obtained based on the collected water volume and collection time, and the tail water generation rate is used as the initial calibration value of the tail water.

[0049] The method of obtaining the tail water discharge generation rate based on the collected water volume and the collection time includes: obtaining the tail water discharge generation rate by dividing the collected water volume by the collection time.

[0050] In a specific example, when the operating current is I1, after the voltage of the fuel cell is stabilized, tail water is collected for a seconds and the collected water volume is b liters, then the tail water generation rate is b divided by a.

[0051] Optionally, in the collected tail water, the tail water is condensed water in the cathode tail gas and / or condensed water in the anode tail gas.

[0052] Step S102: during the operation of the fuel cell, recording the initial time t1 of the fuel cell and the time t2 when the tail water of the fuel cell reaches the set position, and recording the operating current of the fuel cell between the time t1 and the time t2;

[0053] Record the working current of the fuel cell between time t1 and time t2, that is, the working current of the fuel cell between time t1 and time t2 may be constantly changing, such as working for m seconds at the working current I1, working for n seconds at the working current I2, working for h seconds at the working current I3, and so on.

[0054] Step S103: obtaining an initial calibration value of tail water discharge corresponding to the working current based on the working current of the fuel cell between time t1 and time t2;

[0055] The tail drain initial calibration value corresponding to the working current I1, the tail drain initial calibration value corresponding to the working current I2, and the tail drain initial calibration value corresponding to the working current I3 are obtained respectively.

[0056] Step S104: obtaining a calibrated generated water volume V0 based on the time t1, the time t2 and the tail water discharge initial calibration value corresponding to the working current;

[0057] Use the initial calibration value of the tail water discharge corresponding to the working current I1 multiplied by m, the initial calibration value of the tail water discharge corresponding to the working current I2 multiplied by n, the initial calibration value of the tail water discharge corresponding to the working current I3 multiplied by h, and so on, and then add the calculated results to get the calibrated generated water volume V0.

[0058] Step S105: obtaining the actual amount of water V1 generated by the fuel cell from time t1 to time t2 based on the set position;

[0059] Optionally, during the operation of the fuel cell, the initial time t1 of the fuel cell and the time t2 when the tail water of the fuel cell reaches a set position are recorded, and the set position is obtained based on a liquid level sensor arranged in a real-time collection device for the tail water.

[0060] Optionally, during the operation of the fuel cell, recording the initial time t1 of the fuel cell and the time t2 when the tail water of the fuel cell reaches the set position includes:

[0061] When the tail drainage in the tail drainage real-time collection device reaches the set position, the tail drainage in the tail drainage real-time collection device is discharged.

[0062] In a specific embodiment, the amount of water in the tailwater drainage real-time collection device can be obtained based on the position of the liquid level sensor of the tailwater drainage real-time collection device, that is, the actual amount of water V1 generated.

[0063] The structure of the tailwater real-time collection device is as follows: Figure 2 As shown, it includes a box body 2, a liquid level sensor 4 and a solenoid valve 6. The box body 2 is provided with an air outlet 3, a water inlet 1 and a drain 5. The liquid level sensor 4 is provided on the box body 2 and is used to monitor the liquid level in the box body 2. The solenoid valve is provided on the drain 5.

[0064] Step S106: Obtain monitoring results based on the comparison result between the actual generated water volume V1 and the calibrated generated water volume V0.

[0065] Optionally, the monitoring result is obtained based on the comparison result of the actually generated water volume V1 and the calibrated generated water volume V0, including:

[0066] When V1 is greater than V0, it is flooded, and when V1 is less than V0, it is dry.

[0067] Optionally, in the monitoring result obtained based on the comparison result between the actually generated water volume V1 and the calibrated generated water volume V0, the error of the calibrated generated water volume V0 is set to 10%.

[0068] Optionally, the monitoring result obtained based on the comparison result between the actually generated water volume V1 and the calibrated generated water volume V0 includes:

[0069] If 0.9V0 < V1 < 1.1V0, the water balance is in a normal state. If V1 > 1.1V0, it is waterlogging, and the air flow is increased for purging to drain the water inside the fuel cell stack. If V1 < 0.9V0, it is membrane drying, and the stack temperature is reduced and the air humidity is increased.

[0070] In this embodiment, the internal water content is judged by monitoring the generation rate of the tail drainage of the fuel cell. First, the water generation rate at different currents is calibrated. During the actual operation, the water generation speed is statistically analyzed in real time, and compared with the calibrated value through an automated program. Judgments are made according to the comparison results to clarify the waterlogging and membrane drying states and issue warnings.

[0071] The specific steps are as follows:

[0072] 1. Initial calibration value: During the polarization curve test of the fuel cell engine, for each current point, after the voltage is stabilized, start collecting the tail drainage of the cathode and anode. The tail drainage can be the condensed water in the respective tail gases of the cathode and anode, or the condensed water collected after mixing the cathode and anode tail gases in the mixed exhaust, and record the water volume and the collection time. Divide the water volume by the time as the water generation rate and use it as the initial calibration value.

[0073] 2. The real-time collection device for tail drainage is as Figure 2 shown, and the generation rate of the tail drainage is monitored in real time based on the Figure 3 shown control logic. After starting the engine, record the initial time t1, and at the same time start recording the operating conditions of the working conditions and statistically analyze the operating time of each current. When the tail drainage accumulates in the box to trigger the liquid level sensor, record the time t2 and open the solenoid valve for drainage. The initial time t1 can be the startup time or any time during the operation of the fuel cell, and the embodiment is not limited to the startup time.

[0074] 3. Judgment of water balance state: According to the operating time of the current under each working condition and the calibrated tail water generation rate during the period from t1 to t2, calculate the water volume V0 that should be generated during calibration, and take -10% - 10% as the error range. Compare it with the actual water production volume V1. If 0.9V0 < V1 < 1.1V0, it is judged that the water balance is in a normal state. If V1 > 1.1V0, it is judged as waterlogging, and the air flow needs to be increased for purging to drain the water inside the stack. If V1 < 0.9V0, it is judged as membrane drying, and the stack temperature needs to be reduced and the air humidity needs to be increased.

[0075] 4. Continuous monitoring: If it is judged to stop, the program terminates. If it is judged not to stop, it repeats and enters the loop to continuously monitor the water balance state.

[0076] The monitoring method of this embodiment can be used to identify the states of membrane drying and waterlogging, and avoids the interference of water balance judgment caused by other factors. It does not require complex equipment and can monitor in real time.

[0077] This embodiment can identify membrane drying and waterlogging through water balance monitoring and adopt corresponding countermeasures, which can avoid the durability problems caused by membrane drying and waterlogging and is beneficial to improving the stack life.

[0078] This embodiment can identify whether the operating parameters of the fuel cell system have changed. If membrane drying or waterlogging continuously occurs, it is judged that some parameters are inappropriate, and early warning can be given and manual intervention can be carried out to adjust the parameters to appropriate levels.

[0079] The basic principles of the present disclosure are described above in combination with specific embodiments. However, it should be noted that the advantages, advantages, effects, etc. mentioned in the present disclosure are only examples and not limitations, and it cannot be considered that these advantages, advantages, effects, etc. are essential for each embodiment of the present disclosure. In addition, the above-mentioned specific details are only for the purpose of illustration and easy understanding, rather than limitations. The above details do not limit the present disclosure to necessarily adopt the above specific details to implement.

[0080] In the present disclosure, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. The block diagrams of the devices, devices, equipment, and systems involved in the present disclosure are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, devices, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

[0081] Additionally, as used herein, "or" used in a list of items beginning with "at least one" indicates a separate list, so that, for example, a list of "at least one of A, B, or C" means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). Furthermore, the word "exemplary" does not mean that the example described is preferred or better than other examples.

[0082] It should also be noted that in the system and method of the present disclosure, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present disclosure.

[0083] Various changes, substitutions, and modifications of the techniques described herein may be made without departing from the teachings defined by the appended claims. Furthermore, the scope of the claims of the present disclosure is not limited to the specific aspects of the processes, machines, manufactures, compositions of events, means, methods, and actions described above. Currently existing or later to be developed processes, machines, manufactures, compositions of events, means, methods, or actions that perform substantially the same functions or achieve substantially the same results as the corresponding aspects described herein may be utilized. Thus, the appended claims include such processes, machines, manufactures, compositions of events, means, methods, or actions within their scope.

[0084] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0085] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present disclosure to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A method for monitoring water balance of a fuel cell system, characterized in that: Including: During the polarization curve test of the fuel cell engine, obtaining the initial calibration value of the tail drain water at different operating currents of the fuel cell, including: During the polarization curve test of the fuel cell engine, for each current point, after the voltage is stabilized, collect the tail drain water, record the collected water volume and the collection time, obtain the tail drain water generation rate based on the collected water volume and the collection time, and use the tail drain water generation rate as the initial calibration value of the tail drain water; During the operation of the fuel cell, record the initial time t1 of the fuel cell and the time t2 when the tail drain water of the fuel cell reaches the set position, and record the operating current of the fuel cell between the time t1 and the time t2; Obtain the initial calibration value of the tail drain water corresponding to the operating current based on the operating current of the fuel cell between the time t1 and the time t2; Obtain the calibrated generated water volume V0 based on the time t1, the time t2, and the initial calibration value of the tail drain water corresponding to the operating current; Obtain the actually generated water volume V1 of the fuel cell from the time t1 to the time t2 based on the set position; Obtain the monitoring result based on the comparison result between the actually generated water volume V1 and the calibrated generated water volume V0.

2. The fuel cell system water balance monitoring method according to claim 1, characterized in that: The obtaining the tail drain water generation rate based on the collected water volume and the collection time includes: Dividing the collected water volume by the collection time to obtain the tail drain water generation rate.

3. The method for monitoring water balance of a fuel cell system according to claim 1, characterized in that: In the collection of the tail drain water, the tail drain water is the condensed water in the cathode exhaust gas and / or the condensed water in the anode exhaust gas.

4. The method for monitoring water balance of a fuel cell system according to claim 1, characterized in that: During the operation of the fuel cell, in the recording of the initial time t1 of the fuel cell and the time t2 when the tail drain water of the fuel cell reaches the set position, the set position is obtained based on the liquid level sensor provided in the tail drain water real-time collection device.

5. The method for monitoring water balance of a fuel cell system according to claim 4, characterized in that: During the operation of the fuel cell, the recording of the initial time t1 of the fuel cell and the time t2 when the tail drain water of the fuel cell reaches the set position includes: When the tail drain water in the tail drain water real-time collection device reaches the set position, drain the tail drain water in the tail drain water real-time collection device.

6. The method for monitoring water balance of a fuel cell system according to claim 1, characterized in that: The obtaining the monitoring result based on the comparison result between the actually generated water volume V1 and the calibrated generated water volume V0 includes: When V1 is greater than V0, it is waterlogging, and when V1 is less than V0, it is membrane dryness.

7. The method for monitoring water balance of a fuel cell system according to claim 6, characterized in that: In the obtaining the monitoring result based on the comparison result between the actually generated water volume V1 and the calibrated generated water volume V0, the error of the calibrated generated water volume V0 is set to 10%.

8. The method for monitoring water balance of a fuel cell system according to claim 7, characterized in that: The obtaining the monitoring result based on the comparison result between the actually generated water volume V1 and the calibrated generated water volume V0 includes: If 0.9V0 < V1 < 1.1V0, the water balance is in a normal state. If V1 > 1.1V0, it is waterlogging, increase the air flow for purging to drain the water inside the fuel cell stack. If V1 < 0.9V0, it is membrane dryness, reduce the stack temperature and increase the air humidity.

9. A fuel cell system water balance monitoring device, characterized in that: Including: A calibration module, used to obtain the initial calibration value of the tail drain water at different operating currents of the fuel cell during the polarization curve test of the fuel cell engine, including: During the polarization curve test of the fuel cell engine, for each current point, after the voltage is stabilized, collect the tail drain water, record the collected water volume and the collection time, obtain the tail drain water generation rate based on the collected water volume and the collection time, and use the tail drain water generation rate as the initial calibration value of the tail drain water; A recording module, used to record the initial time t1 of the fuel cell and the time t2 when the tail water of the fuel cell reaches the set position during the operation of the fuel cell, and to record the operating current of the fuel cell between the time t1 and the time t2; A calibration value acquisition module, used to obtain an initial calibration value of tail water discharge corresponding to the working current based on the working current of the fuel cell between time t1 and time t2; A calculation module, used for obtaining a calibrated generated water volume V0 based on the time t1, the time t2 and the initial calibration value of the tail water discharge corresponding to the working current; An actual water volume module, used to obtain the actual water volume V1 generated by the fuel cell from time t1 to time t2 based on the set position; The monitoring module is used to obtain a monitoring result based on a comparison result between the actual generated water volume V1 and the calibrated generated water volume V0.

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