Method for measuring gas leakage rate of stack with external manifold
By setting up a test device at the target node of the manifold external SOFC stack, detecting the gas state and calculating the leakage rate, the problem that the stack is difficult to judge the cause of gas leakage under high back pressure conditions is solved, and rapid and accurate detection and stack improvement are achieved, extending the service life.
Patent Information
- Application Number
- CN202510122594.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-26
- Publication Date
- 2025-04-11
AI Technical Summary
It is difficult to quickly and accurately determine the cause of gas leakage under high back pressure conditions, resulting in a reduced service life.
By setting up a test device at the target node of the stack, the gas state is detected, the instantaneous leakage rate is calculated, and corresponding improvement plans are carried out based on the comprehensive analysis of leakage rate and performance attenuation.
It realizes rapid and accurate detection of stack gas leakage, provides evidence for stack performance evolution laws, guides stack improvement, and extends service life.
Smart Images
Figure CN119803806A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the technical field of gas leakage testing, and in particular to a method for measuring the gas leakage rate of a manifold-external fuel cell stack. Background Art
[0002] Solid oxide fuel cell (SOFC) is a promising fuel cell with advantages such as high energy conversion efficiency, wide range of fuel selection, high cogeneration efficiency, green environmental protection, easy modular assembly, and no need for precious metal catalysts. SOFC stacks are mainly used in portable power supplies, distributed power generation / cogeneration systems, high-performance power supplies, large power stations, etc.
[0003] In the related art, the long-term stability of SOFC stacks in actual working conditions determines their service life, but performance degradation such as leakage will seriously deteriorate their service life. Among them, the leakage of the stack under high back pressure conditions in the power generation system will significantly reduce its service life. However, given that the manifold-external SOFC stack requires high temperature and the difficulty of sealing both the anode and cathode, it is particularly difficult to quickly and accurately determine the cause of the stack leakage.
[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention
[0005] The purpose of the present disclosure is to overcome the above-mentioned shortcomings of the prior art and provide a method for measuring the gas leakage rate of a manifold-external fuel cell stack, so as to effectively detect the gas leakage of the fuel cell stack, thereby providing effective evidence for the evolution law of fuel cell stack performance and guiding the improvement of the fuel cell stack.
[0006] According to a first aspect of the present disclosure, a method for measuring a gas leakage rate of a manifold-external fuel cell stack is provided, comprising:
[0007] Setting a test device at a target node of the battery stack;
[0008] The testing device detects the gas state of the target node;
[0009] Determine a first parameter according to a test result of the test device;
[0010] Obtaining a third parameter based on a comprehensive analysis of the first parameter and the second parameter;
[0011] The first parameter is compared with the third parameter, wherein when the first parameter is greater than the third parameter in a first time period, a first scheme improvement is performed; when the first parameter is greater than the third parameter in a second time period, a second scheme improvement is performed; wherein the first time period is less than the second time period.
[0012] According to an embodiment of the present disclosure, when a test device is set at the target node, the target node includes an outlet of the gas flow channel, an outlet of the air flow channel, and an intersection of the gas flow channel and the air flow channel.
[0013] According to an embodiment of the present disclosure, when the test device detects the gas state of the target node, the voltage of the battery stack is detected by a voltage detection device. When the voltage of the battery stack is displayed as normal, it is determined that the battery stack is operating normally, and no subsequent detection is performed.
[0014] According to an embodiment of the present disclosure, when the test device detects the target node, if the test device displays normal, it is determined that the battery stack is operating normally, and no subsequent detection is performed.
[0015] According to an embodiment of the present disclosure, the first parameter is measured in the following manner:
[0016] α=limΔt→0(ΔV / Δt)
[0017] p1+1 / 2ρv1 2 +ρgh1=p2+1 / 2ρv2 2 +ρgh2
[0018] Among them, α is the instantaneous leakage rate of the target node; Δt is the change in time; ΔV is the change value of the test device; p1 is the pressure at the inlet of the target node; p2 is the pressure at the outlet of the target node; v1 is the gas flow rate at the inlet of the target node; v2 is the gas flow rate at the outlet of the target node; h1 is the height at the inlet of the target node, h2 is the height at the outlet of the target node, ρ represents the gas density, and g is the acceleration of gravity.
[0019] According to an embodiment of the present disclosure, the first parameter is compared with the second parameter to determine a gas leakage rate threshold.
[0020] According to one embodiment of the present disclosure, when a first parameter is determined based on the test results of the test device, if the first parameter is less than the gas leakage rate threshold, the fuel cell stack is determined to be operating normally and no subsequent detection is performed; if the first parameter is greater than the gas leakage rate threshold, the fuel cell stack is determined to be abnormal and subsequent detection is performed.
[0021] According to an embodiment of the present disclosure, when the third parameter is obtained based on the comprehensive analysis of the first parameter and the second parameter, the second parameter is measured based on the performance attenuation of the fuel cell stack.
[0022] According to an embodiment of the present disclosure, the first parameter is compared with the third parameter, wherein, when the first parameter is greater than the third parameter in the first time period, the first scheme is improved; when the first parameter is greater than the third parameter in the second time period, the second scheme is improved; wherein, the first time period is less than the second time period; the first time period is less than 10 hours; and the second time period is between 10 and 500 hours.
[0023] According to an embodiment of the present disclosure, the first parameter is compared with the third parameter, wherein when the first parameter is greater than the third parameter in the first time period, a first scheme improvement is performed; when the first parameter is greater than the third parameter in the second time period, a second scheme improvement is performed; wherein, when the first time period is less than the second time period; the first scheme includes optimizing the assembly scheme of the fuel cell stack; the second scheme includes optimizing the raw material scheme of the fuel cell stack.
[0024] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.
[0026] Figure 1 The present invention is a schematic diagram of the measurement steps of a method for measuring the gas leakage rate of a fuel cell stack with an external manifold in one embodiment of the present invention.
[0027] Figure 2 A schematic diagram of a target node in one embodiment of the present disclosure.
[0028] Figure 3 This is a graph showing the relationship between the change in liquid height in a testing device and time in one embodiment of the present disclosure.
[0029] Figure 4 The figure is a schematic diagram of a measurement process of a measurement method in one embodiment of the present disclosure. DETAILED DESCRIPTION
[0030] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.
[0031] In the relevant technology, the long-term stability of SOFC stacks in actual working conditions determines their service life, but performance degradation such as leakage will seriously deteriorate their service life. Among them, the leakage of the stack under high back pressure conditions in the power generation system will significantly reduce its service life. However, given that the manifold-external SOFC stack requires high temperature and the difficulty of sealing both the anode and cathode, it is particularly difficult to quickly and accurately determine the cause of the stack leakage.
[0032] At the same time, the inventors have continuously verified that the main reasons for the leakage of the fuel cell stack are caused by two aspects: first, the unreasonable fuel cell stack assembly plan; second, the unreasonable design of the fuel cell stack raw materials. However, for the fuel cell stack assembly plan, it can be discovered in short-term testing; while the fuel cell stack raw material design requires long-term testing to be discovered.
[0033] Based on this, see Figure 1 The embodiment of the present disclosure provides a method for measuring the gas leakage rate of a manifold-external fuel cell stack. The measurement method can effectively, quickly and accurately detect fuel cell stack gas leakage, thereby providing effective evidence for the evolution law of fuel cell stack performance, and further guiding the improvement of fuel cell stacks.
[0034] The measurement method includes:
[0035] S1: Setting up a test device at the target node of the stack;
[0036] S2: The test device detects the gas state of the target node;
[0037] S3: Determine a first parameter according to a test result of the test device;
[0038] S4: Obtaining a third parameter based on a comprehensive analysis of the first parameter and the second parameter;
[0039] S5: Compare the first parameter with the third parameter, wherein when the first parameter is greater than the third parameter in the first time period, improve the first solution; when the first parameter is greater than the third parameter in the second time period, improve the second solution; wherein the first time period is less than the second time period.
[0040] In an embodiment of the present disclosure, a test device is installed at a target node position, and the test device detects the gas state of the target node of the fuel cell stack. A first parameter is calculated based on the test result of the target node, and a third parameter is obtained by comprehensively comparing the first parameter with the second parameter. If the first parameter is greater than the third parameter within a first time period, the fuel cell stack can be improved by a first scheme; if the first parameter is greater than the third parameter within a second time period, the second scheme is improved, thereby achieving guided improvement of the fuel cell stack.
[0041] As an example, the test device can be a water tank. When testing the target node of the battery stack, the target node of the battery stack can be inserted into the water tank, and the gas state of the target node can be reflected by the water level change in the water tank. The working process is roughly as follows: connect the target node to the water tank, close the gas valve during testing, and judge the state of the target node according to the change of the liquid level in the water tank.
[0042] It can be understood that if the liquid level of the water tank corresponding to the target node does not change, it indicates that the target node is in a normal state; if the liquid level of the water tank corresponding to the target node changes, it indicates that there is an abnormality in the target node.
[0043] Figure 2 is a schematic diagram of the target node, wherein A1 represents the gas flow channel inlet, A2 represents the gas flow channel outlet, B1 represents the air flow channel inlet, B2 represents the air flow channel outlet; C represents the intersection of the air flow channel and the gas flow channel.
[0044] In some embodiments of the present disclosure, the target node includes an outlet of the gas flow channel, an outlet of the air flow channel, and an intersection of the gas flow channel and the air flow channel.
[0045] According to the location of gas leakage, it can be divided into gas leakage on the outlet side of the gas flow channel, gas leakage on the outlet side of the air flow channel, and gas cross-talk between the gas flow channel and the air flow channel.
[0046] Specifically, when detecting the gas state on the outlet side of the gas flow channel, the outlet of the gas flow channel is connected to the testing device. If the testing device does not change, it means that there is no abnormality on the outlet side of the gas flow channel. If the testing device changes, it means that there is an abnormality in the gas pipeline.
[0047] When testing the gas state on the outlet side of the air flow channel, the outlet of the air flow channel is connected to the testing device. If the testing device does not change, it means that there is no abnormality in the air flow channel. If the testing device changes, it means that there is an abnormality in the air duct.
[0048] Furthermore, when detecting the intersection of the air flow channel and the gas flow channel, the intersection of the air flow channel and the gas flow channel is connected to a testing device. If the testing device changes, it indicates that there is an abnormality in the air flow channel and the gas flow channel; if the testing device does not change, it indicates that the air flow channel and the gas flow channel are in a normal state.
[0049] It should be noted that the outlet of the gas flow channel is connected to the test device. If the test device displays normal, it indicates that the fuel cell stack is in a normal state and no subsequent steps are performed; the outlet of the air flow channel is connected to the test device. If the test device displays normal, it indicates that the fuel cell stack is in a normal state and no subsequent steps are performed; the intersection of the air flow channel and the gas flow channel is connected to the test device. If the test device displays normal, it indicates that the fuel cell stack is in a normal state and no subsequent tests are performed.
[0050] Furthermore, as an example, the normality of the air flow channel and the gas flow channel can also be determined by measuring the voltage of the battery stack. Specifically, the voltage of the battery stack can be detected by a voltage detection device. When the voltage of the battery stack is normal, it is determined that the battery stack is operating normally (the state of the intersection of the air flow channel and the gas flow channel is normal), and no subsequent detection of the battery stack is performed; if the voltage of the battery stack is abnormal, it is determined that there is an abnormality at the intersection of the air flow channel and the gas flow channel, and the battery stack needs to be tested subsequently.
[0051] If the test equipment is changed or the voltage check equipment detects an abnormality, the following tests will be required to further verify the stack.
[0052] In some embodiments of the present disclosure, when the first parameter is determined based on the test result of the test device, the first parameter is measured in the following manner:
[0053] α=limΔt→0(ΔV / Δt)(1)
[0054] p1+1 / 2ρv1 2 +ρgh1=p2+1 / 2ρv2 2 +ρgh2(2)
[0055] Among them, α is the instantaneous leakage rate of the target node; Δt is the change in time; ΔV is the change value of the test device; p1 is the pressure at the inlet of the target node; p2 is the pressure at the outlet of the target node; v1 is the gas flow rate at the inlet of the target node; v2 is the gas flow rate at the outlet of the target node; h1 is the height at the inlet of the target node, h2 is the height at the outlet of the target node, ρ represents the gas density, and g is the acceleration of gravity.
[0056] Figure 3The relationship between the liquid level height and time of the test device is shown in the figure (L is the liquid level height of the test device, t is time, the figure mainly shows the change of the liquid level height over time, Va represents the reflux speed of the liquid in the test device at the target node), see Figure 3 , the leakage at a certain moment is the return flow rate of the target node.
[0057] By using the above formula (1), the return flow rate of the target node at a certain moment is determined. The return flow rate determined by formula (1) is substituted into formula (2) to calculate the leakage rate at the target node, which is the first parameter.
[0058] In some embodiments of the present disclosure, the first parameter is compared with the second parameter to obtain a gas leakage rate threshold.
[0059] In this embodiment, when the third parameter is obtained by comprehensive analysis of the first parameter and the second parameter, the second parameter is measured according to the performance attenuation of the battery stack. For example, the performance attenuation value of the battery stack can be continuously detected by the control system, and the control system can measure the attenuation rate of the battery stack according to the attenuation performance of the battery stack, and the attenuation rate is the second parameter. It should be noted that the determination of the attenuation rate of the battery stack by the control system is a technology well known to those skilled in the art, and the embodiments of the present disclosure will not be elaborated on this.
[0060] Furthermore, when the first parameter is determined based on the test results of the test device, if the first parameter is less than the gas leakage rate threshold, it is determined that the fuel cell stack is operating normally and no subsequent detection is performed; if the first parameter is greater than the gas leakage rate threshold, it is determined that the fuel cell stack is abnormal and subsequent detection is performed.
[0061] It can be understood that when the first parameter is less than the gas leakage rate threshold, it means that the gas leakage rate of the target node is within an acceptable range, indicating that the fuel cell stack is in a normal state and no subsequent detection of the fuel cell stack is required; if the first parameter is greater than the gas leakage rate threshold, it means that the gas leakage rate of the target node is unacceptable, indicating that the fuel cell stack is in an abnormal state and further detection of the fuel cell stack is required.
[0062] Furthermore, if the first parameter is greater than the gas leakage rate threshold, the fuel cell stack needs to be tested. The following is a detailed description of the testing method.
[0063] In some disclosed embodiments, if the first parameter is greater than the third parameter in the first time period, the first scheme is improved; if the first parameter is greater than the third parameter in the second time period, the second scheme is improved; specifically, the first time period is less than the second time period; the first time period is less than 10 hours; the second time period is between 10 and 500 hours.
[0064] It is understandable that if the first parameter is greater than the third parameter during testing of the battery stack within 10 hours, the battery stack needs to be improved according to the first solution. For example, the time can be 1h, 3h, 5h, 7h, 9h, etc., and this application does not impose specific restrictions on this. If the first parameter is greater than the third parameter between 10 and 500 hours, the battery stack needs to be improved according to the second solution. In terms of distance, the time can be 10h, 100h, 200h, 400h, 500h, etc., and this application does not impose specific restrictions on this.
[0065] In some disclosed embodiments, the first solution includes optimizing the assembly solution of the fuel cell stack; the second solution includes optimizing the raw material solution of the fuel cell stack.
[0066] Figure 4 The measurement flow diagram of the disclosed measurement method is illustrated. Specifically, if the first parameter is greater than the third parameter within 10 hours, it indicates that there is room for improvement in the structure of the battery stack, and the test result can be used to guide the optimization of the assembly of the battery stack. If the first parameter is greater than the third parameter between 10 and 500 hours, it indicates that there is room for improvement in the raw materials of the battery stack, and the test result can be used to guide the improvement of the raw materials of the battery stack.
[0067] In summary, the disclosed embodiments can not only detect whether the fuel cell stack is normal or not, but also provide guidance to the fuel cell stack according to the relevant test results of the fuel cell stack, so as to provide certain support for the fuel cell stack optimization plan.
[0068] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.
Claims
1. A method for measuring the gas leakage rate of a manifold-external fuel cell stack, characterized in that: include: Setting a test device at a target node of the battery stack; The testing device detects the gas state of the target node; Determine a first parameter according to a test result of the test device; Obtaining a third parameter based on a comprehensive analysis of the first parameter and the second parameter; The first parameter is compared with the third parameter, wherein when the first parameter is greater than the third parameter in a first time period, a first scheme improvement is performed; when the first parameter is greater than the third parameter in a second time period, a second scheme improvement is performed; wherein the first time period is less than the second time period.
2. The method for measuring gas leakage rate of an external manifold type fuel cell stack according to claim 1, characterized in that: When the test device is arranged at the target node, the target node includes the outlet of the gas flow channel, the outlet of the air flow channel, and the intersection of the gas flow channel and the air flow channel.
3. The method for measuring the gas leakage rate of an external manifold type fuel cell stack according to claim 1, characterized in that: When the test device detects the gas state of the target node, the voltage of the battery stack is detected by a voltage detection device. When the voltage of the battery stack is displayed as normal, it is determined that the battery stack is operating normally and no subsequent detection is performed.
4. The method for measuring gas leakage rate of an external manifold type fuel cell stack according to claim 1, characterized in that: When the test device detects the target node, if the test device displays normal information, it is determined that the battery stack is operating normally, and no subsequent detection is performed.
5. The method for measuring gas leakage rate of an external manifold type fuel cell stack according to claim 1, characterized in that: The first parameter is measured in the following manner: α=limΔt→0(ΔV / Δt) p1+1 / 2ρv1 2 +ρgh1=p2+1 / 2ρv2 2 +ρgh2 Among them, α is the instantaneous leakage rate of the target node; Δt is the change in time; ΔV is the change value of the test device; p1 is the pressure at the inlet of the target node; p2 is the pressure at the outlet of the target node; v1 is the gas flow rate at the inlet of the target node; v2 is the gas flow rate at the outlet of the target node; h1 is the height at the inlet of the target node, h2 is the height at the outlet of the target node, ρ represents the gas density, and g is the acceleration of gravity.
6. The method for measuring gas leakage rate of an external manifold type fuel cell stack according to claim 1, characterized in that: The first parameter is compared with the second parameter to obtain a gas leakage rate threshold.
7. The method for measuring gas leakage rate of an external manifold type fuel cell stack according to claim 1, characterized in that: When a first parameter is determined based on the test results of the test device, if the first parameter is less than the gas leakage rate threshold, it is determined that the fuel cell stack is operating normally and no subsequent detection is performed; if the first parameter is greater than the gas leakage rate threshold, it is determined that the fuel cell stack is operating abnormally and subsequent detection is performed.
8. The method for measuring gas leakage rate of an external manifold type fuel cell stack according to claim 1, characterized in that: When the third parameter is obtained based on the comprehensive analysis of the first parameter and the second parameter; the second parameter is measured based on the performance attenuation of the battery stack.
9. The method for measuring gas leakage rate of an external manifold type fuel cell stack according to claim 1, characterized in that: The first parameter is compared with the third parameter, wherein, when the first parameter is greater than the third parameter in the first time period, the first scheme is improved; when the first parameter is greater than the third parameter in the second time period, the second scheme is improved; wherein, the first time period is less than the second time period; the first time period is less than 10 hours; and the second time period is between 10 and 500 hours.
10. The method for measuring gas leakage rate of an external manifold type fuel cell stack according to claim 1, characterized in that: The first parameter is compared with the third parameter, wherein when the first parameter is greater than the third parameter in the first time period, a first scheme improvement is performed; when the first parameter is greater than the third parameter in the second time period, a second scheme improvement is performed; wherein, when the first time period is less than the second time period; the first scheme includes optimizing the assembly scheme of the fuel cell stack; the second scheme includes optimizing the raw material scheme of the fuel cell stack.