A method for detecting internal working conditions of a flat tube fuel cell

Abstract

The application discloses a kind of flat tube type fuel cell internal working condition detection methods, comprising: along the two ends of flat tube type fuel cell, it is clamped and fixed;Sample tube is inserted into the anode gas passage of the flat tube type fuel cell by the clamp of any end;Adjust the position of the sample tube air inlet to carry out multipoint sampling;Analysis of the composition of all the sample gas and establish the concentration field of gas composition.The flat tube type fuel cell internal working condition detection method provided by the application meets the distribution of gas concentration field and even temperature field in real time in situ, can accurately monitor and analyze the internal working condition of flat tube type fuel cell, to improve the design of flat tube type fuel cell, and provide basis for its safety and efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fuel cell, in particular to a kind of flat tube type fuel cell internal working condition detection method. BACKGROUND

[0002] Solid oxide fuel cell can be divided into flat plate type, tube type and the like according to configuration, in recent years, Ningbo Institute of Materials also proposes a kind of flat tube type fuel cell, has the advantages of flat plate type and tube type fuel cell.The anode of the SOFC of this structure includes anode gas passage composed of a plurality of tubular structures.Fuel introduced by external gas supply device diffuses to the anode region of the cell through the passage, participates in anode electrochemical reaction, and directly converts the chemical energy of fuel into electrical energy.

[0003] With the degree of fuel participating in the reaction, the change of cell internal temperature, fuel concentration, the gas composition in each part of the SOFC anode gas passage will inevitably exist difference.The chemical reaction or electrochemical reaction of fuel at the anode end exists endothermic or exothermic, and the difference in atmosphere will eventually lead to uneven heat distribution in the cell, thermal stress exists in the cell and the whole system, which may eventually lead to low fuel utilization, cell damage and even destruction failure and other situations.The existing research on the internal gas of flat tube type SOFC anode mostly collects the mixed internal gas discharged from the cell, and the internal gas of each part of the SOFC is only theoretically modeled and calculated, and there is lack of effective sampling and analysis means.Therefore, a kind of real-time and accurate monitoring of the running state of the cell is needed. SUMMARY

[0004] The purpose of the present application is to provide a kind of flat tube type fuel cell internal working condition detection method, which can accurately monitor and analyze the internal working condition of flat tube type fuel cell, and ensure its safe and efficient operation.

[0005] To achieve the above purpose, the present application provides a kind of flat tube type fuel cell internal state detection method, comprising:

[0006] Clamp and fix along the two ends of the flat tube type fuel cell;

[0007] Insert the sampling tube through the clamp of any end into the anode gas passage of the flat tube type fuel cell;

[0008] Adjust the position of the sampling tube inlet to take multiple samples;

[0009] Analyze the composition of all the sampling gas and establish the concentration field of the gas composition.

[0010] Optionally, it further comprises:

[0011] Insert the temperature measuring probe through the clamp into the anode gas passage;

[0012] adjusting the position of the temperature measuring probe to perform multi-point temperature measurement;

[0013] establishing a temperature field inside the flat-tube fuel cell according to the temperature data of the multi-point temperature measurement.

[0014] Optionally, the clamp is in the shape of a n-shaped, and the inner side of the two side walls of the n-shaped clamp is provided with a limiting step for clamping the flat-tube fuel cell, so that a cavity is formed between the clamp and the end of the flat-tube fuel cell; one of the clamps at the two ends of the flat-tube fuel cell is provided with an anode gas inlet hole, and the other is provided with an anode gas outlet hole; and any one of the clamps at the two ends is provided with a detection hole communicating with the cavity.

[0015] Optionally, the outer diameter of the sampling tube and the outer diameter of the temperature measuring probe are less than or equal to 1 / 3 of the inner diameter of the anode gas passage.

[0016] Optionally, the detection hole is provided with a positioning sleeve.

[0017] Optionally, between the step of adjusting the position of the sampling tube to perform multi-point sampling and the step of analyzing the composition of all the sampling gas and establishing the concentration field of the gas composition, the method further comprises drying the sampling gas and introducing the dried sampling gas into a sealed container.

[0018] Optionally, the step of analyzing the composition of all the sampling gas and establishing the concentration field of the gas composition comprises: using a chromatographic sampling needle to extract the sampling gas in the sealed container and inject it into a chromatographic analyzer for chromatographic analysis, and determining the gas composition and proportion according to the chromatographic analysis result.

[0019] Optionally, the step of adjusting the position of the temperature measuring probe to perform multi-point temperature measurement is adjusting the temperature measuring position of the temperature measuring probe and coinciding with the sampling position.

[0020] Optionally, the method further comprises, before the step of adjusting the position of the sampling tube to perform multi-point sampling, discharging the original atmosphere in the sealed container and the sampling tube.

[0021] With respect to the above background technology, the flat-tube fuel cell internal working condition detection method provided by the present application fixes the flat-tube fuel cell by clamps at both ends of the flat-tube fuel cell, uses a sampling tube to extend into the interior of the flat-tube fuel cell through the clamps, adjusts the position of the sampling tube to perform multi-point sampling, analyzes the composition of the sampling gas sampled in situ and in real time multiple times, establishes a concentration field reflecting the gas distribution, and directly and accurately monitors the internal working condition of the flat-tube fuel cell, so as to optimize the flat-tube fuel cell according to the internal working condition and ensure safe operation. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to make the technical solutions in the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description only aim at some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without any creative effort based on the provided drawings.

[0023] Figure 1 The flow chart of the internal working condition detection method of the flat tube fuel cell provided by the embodiments of the present application;

[0024] Figure 2 The schematic diagram of the gas sampling detection of the embodiments of the present application;

[0025] Figure 3 The schematic diagram of the temperature detection of the embodiments of the present application;

[0026] Figure 4 The schematic diagram of the first clamp provided by the embodiments of the present application;

[0027] Figure 5 The schematic diagram of the second clamp provided by the embodiments of the present application;

[0028] Figure 6 The schematic diagram of the third clamp provided by the embodiments of the present application;

[0029] Figure 7 The gas composition diagram of the same depth at different positions provided by the embodiments of the present application;

[0030] Figure 8 The gas composition diagram of the same gas channel at different depths provided by the embodiments of the present application;

[0031] Figure 9 The gas composition diagram when the gas is dried and nitrogen is removed provided by the embodiments of the present application.

[0032] Wherein:

[0033] 1-flat tube fuel cell, 2-clamp, 3-sampling tube, 4-dry bottle, 5-sample gas bottle, 6-chromatographic sampling needle, 7-chromatographic analyzer, 8-temperature measuring thermocouple, 9-thermocouple display. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort belong to the protection scope of the present application.

[0035] In order to make the technical personnel in the technical field better understand the present application, the present application is further described in detail below in combination with the drawings and specific embodiments.

[0036] Please refer to Figures 1 to 9 , Figure 1 The flow chart of the internal working condition detection method of the flat tube fuel cell provided by the embodiment of the present application is shown in Figure 2 The schematic diagram of the gas sampling detection of the embodiment of the present application is shown in Figure 3 The schematic diagram of the temperature detection of the embodiment of the present application is shown in Figure 4 The schematic diagram of the first clamp provided by the embodiment of the present application is shown in Figure 5 The schematic diagram of the second clamp provided by the embodiment of the present application is shown in Figure 6 The schematic diagram of the third clamp provided by the embodiment of the present application is shown in Figure 7 The gas composition diagram of the same depth at different positions provided by the embodiment of the present application is shown in Figure 8 The gas composition diagram of the same gas passage at different depths provided by the embodiment of the present application is shown in Figure 9 The gas composition diagram when drying and removing nitrogen provided by the embodiment of the present application is shown in Figures 2 to 6 In the figure, a represents anode inlet gas, b represents anode exhaust gas, c represents anode inlet gas, and d represents anode exhaust gas.

[0037] The internal working condition detection method of the flat tube fuel cell provided by the present application is shown in Figure 1 The method comprises the following steps:

[0038] Step 101: clamp and fix the flat tube fuel cell 1 along its two ends; for the flat tube fuel cell 1, the present application particularly provides a suitable clamp 2, by clamping the clamp 2 at the two ends of the flat tube fuel cell 1, the flat tube fuel cell 1 is fixed without affecting the normal anode and cathode gas inlet, and at the same time, the sampling tube 3 can be extended into the different depths of the cell for sampling.

[0039] The structure of the clamp 2 can refer to Figures 4 to 6As shown, different sizes and types of clamps 2 can be selected according to different flat tube fuel cells 1 and test purposes. The clamps 2 at both ends are generally in the shape of a U, and the inner sides of the two side walls of the U are provided with limiting steps to clamp the end of the flat tube fuel cell 1 against the limiting steps, forming a cavity between the clamp 2 and the end of the flat tube fuel cell 1. One of the clamps 2 at both ends is provided with an anode gas inlet hole in the middle, and cathode gas inlet holes are provided on both sides of the anode gas inlet hole. The other clamp 2 is provided with an anode gas outlet hole in the middle, and cathode gas outlet holes are provided on both sides of the anode gas outlet hole. The anode gas inlet hole and the anode gas outlet hole are in communication with the cavity of the corresponding end clamp 2, achieving uniform gas inlet and outlet. One of the clamps 2 is provided with multiple detection holes in communication with the cavity, so that the sampling tube 3 can extend into the anode gas channel of the flat tube fuel cell 1. Of course, the cathode gas outlet holes can also be multiple, and the cathode gas outlet holes simultaneously serve as detection holes for the sampling tube 3 to extend into the anode gas channel. A positioning sleeve is usually provided at the detection hole to position the detection device such as the sampling tube 3 extending into the battery interior, and the positioning sleeve can be screwed with the clamp 2.

[0040] In the execution of the above steps, according to the detection purpose or detection position, a clamp 2 of appropriate size and type is selected. When fixing the flat tube fuel cell 1, the end of the flat tube fuel cell 1 is aligned with the notch of the clamp 2, so that the two corners of the flat tube fuel cell 1 are pressed against the limiting steps, ensuring the sealing of the cavity formed, and avoiding the cathode gas inlet hole and the cathode gas outlet hole being blocked by the clamp 2.

[0041] Step 102: Extend the sampling tube 3 through the clamp 2 at either end into the anode gas channel of the flat tube fuel cell 1. In the above embodiment, the anode gas inlet hole is used for gas inlet and connected with the fuel gas pipeline, and the fuel gas is distributed to different anode gas channels through the cavity. Generally, the sampling tube 3 is extended into the anode gas channel from the cathode gas outlet hole or the detection hole. The diameter of the cathode gas outlet hole or the detection hole of the clamp 2 is about 10 mm, which is larger than the diameter of any anode gas channel, that is, a single detection hole corresponds to multiple anode gas channels, and the detection hole is connected with the positioning sleeve through threads.

[0042] The sampling tube 3 needs to be kept straight in the anode gas channel of the battery, but the part of the sampling tube 3 in the positioning sleeve will have a certain bending, so that the sampling tube 3 is clamped in the inner wall of the positioning sleeve and can be pulled out and extended into different anode gas channels at any time.

[0043] Step 103: adjust the position of the sampling tube 3 to intake gas for multi-point sampling, with the end of the sampling tube 3 as the gas intake part. To facilitate the insertion of the sampling tube 3 into the anode gas channel, the outer diameter of the sampling tube 3 is less than or equal to 1 / 3 of the inner diameter of the anode gas channel. The adjustment of the position of the sampling tube 3 specifically refers to pulling the sampling tube 3 so that the gas intake position of the end of the sampling tube 3 is at the depth of 25mm, 50mm and 75mm of the same anode gas channel in turn, realizing multi-point sampling. Of course, the specific depth can be adjusted flexibly according to needs. In addition, the adjustment of the position of the sampling tube 3 also includes pulling the sampling tube 3 out of the current anode gas channel and inserting it into different positions of other anode gas channels corresponding to the detection hole, or inserting it into different anode gas channels corresponding to another detection hole. To improve sampling accuracy, on the one hand, the sampling speed needs to be controlled to avoid too fast sampling speed causing negative pressure to disturb the distribution of gas components in the anode sampling tube, and the sampling tube 3 is also subject to such consideration; on the other hand, the same depth of the adjacent anode gas channels corresponding to the same detection hole can also be sampled, and then the gas component content is detected and the average value is taken. By adjusting the position of the sampling tube 3, a full range, no dead angle, multi-point, grid-like sampling is realized. The cavity between the clamp 2 and the flat tube fuel cell 1 facilitates the insertion of the capillary sampling needle into any anode gas channel.

[0044] Step 104: analyze the components of all the sampled gas and establish the concentration field of the gas components. According to the results of the above-mentioned multi-point detection of the gas components, the concentration field of the reaction gas components is established, with continuous field line distribution formed by multiple points, the difference between the gas component content and the theoretical gas component content is observed, the running state of the flat tube fuel cell 1 and the possible reasons for the difference are analyzed, which provides a basis for the optimization of the flat tube fuel cell 1 and ensures the safe operation of the flat tube fuel cell 1. The above-mentioned analysis of the sampled gas is specifically chromatographic analysis or mass spectrometric analysis, which determines the composition and content of the gas through chromatographic analysis.

[0045] When using gas component chromatographic analysis, a needle cylinder or a chromatographic sampling needle 6 is needed to extract a volume V of gas, the volume of the extracted gas is greater than the sum of the volume of the sample gas bottle 5, the volume of the pipeline and the actual volume of the sampled gas, and the gas in the chromatographic sampling needle 6 is discharged, at this time the atmosphere left in the sample gas bottle 5 is the atmosphere to be sampled. That is, before chromatographic analysis, the original atmosphere in the sample gas bottle 5 and the pipeline is discharged to ensure the accuracy of the sampling analysis. Since the sampling system composed of the sampling tube 3 and the sample gas bottle 5 only has a sampling hole inside the flat tube fuel cell 1, and the diameter of the sampling tube 3 is extremely small and the aspect ratio is usually greater than 500, it is beneficial to ensure that the anode atmosphere pressure is lower than the gas pressure that automatically flows into the capillary sampling tube, forming a good sealing environment and ensuring that the sample gas is not contaminated.

[0046] Further, in order to improve the detection accuracy of the gas composition, a step 1031 is further included between the step 103 and the step 104, that is, the sampled gas is dried, the dried gas is introduced into the sealed container, and then the gas in the sealed container is extracted and input into the chromatographic analyzer 7 for chromatographic analysis. The process and principle of multi-point sampling, drying and chromatographic analysis are shown in Figure 2 The capillary sampling needle is connected to the drying bottle 4 through a pipeline, and the dried gas in the drying bottle 4 is introduced into the sealed container, that is, the sample gas bottle 5 shown in Figure 2 The bottle opening of the sample gas bottle 5 is sealed with a cap made of silica gel or rubber, and the pipeline and the chromatographic sampling needle 6 are inserted into the cap without damaging the seal of the sample gas bottle 5.

[0047] After obtaining the gas composition and concentration data at different positions inside the battery, the data analysis software is used to fit the in-situ gas concentration field inside the fuel cell. The method includes but is not limited to drawing the corresponding contour map. The contour map reflects the real-time, in-situ and real field distribution of the gas inside the fuel cell.

[0048] For multi-point sampling, the present application takes three anode gas channels A, B and C as an example, A and C are located on both sides of B, and the sampling depth of A and C anode gas channels is 75 mm. B has three sampling depths, which are 25 mm, 50 mm and 75 mm, respectively. Corresponding labels are A75, C75, B25, B50 and B75. During the test, the flat tube fuel cell 1 is supplied with CH4 and CO2 gas, and the methane reforming reaction occurs. The structure of the pre-set time sampling analysis can be referred to Figures 7 to 9 By discharging the original atmosphere in the sealed container, drying the sampled gas and removing nitrogen from the analysis results, the reliability of the sampling analysis is improved, Figure 9 as a result of removing nitrogen.

[0049] In another embodiment of the present application, the internal working condition detection method of the flat tube fuel cell further includes monitoring the temperature distribution inside the flat tube fuel cell 1. Specifically, it includes the step 201 of inserting the temperature measuring probe into the anode gas channel through the clamp 2; the step 202 of adjusting the position of the temperature measuring probe for multi-point temperature measurement; and the step 203 of establishing the temperature field inside the flat tube fuel cell 1 according to the temperature data of the multi-point temperature measurement. The specific devices applied are shown in Figure 3As shown, it comprises a temperature measuring thermocouple 8 and a thermocouple display 9 connected with the temperature measuring thermocouple 8. When measuring the anode gas channel of the flat tube fuel cell 1, the sampling tube 3 is first taken out from the anode gas channel, and then the temperature measuring probe of the temperature measuring thermocouple 8 is inserted into the anode sampling tube through the detection hole. When adjusting the position of the temperature measuring probe for multi-point temperature measurement, the temperature measuring probe is inserted into the same depth of different anode gas channels according to the temperature measurement requirement, or the temperature measuring thermocouple 8 is pulled to adjust the temperature measuring probe at different depths of the same anode gas channel. Finally, the temperature field of the flat tube fuel cell 1 is established according to the temperature data of the multi-point temperature measurement. As preferred, when performing the multi-point temperature measurement, the temperature measuring point can be coincided with the position of the gas sampling point, so as to analyze the operation state of the fuel cell according to the concentration field and the gas temperature field reflecting the gas composition, and to ensure the safe operation of the flat tube fuel cell 1.

[0050] The internal working condition detection method of the flat tube fuel cell provided by the present application realizes the relatively sealed gas sampling through the elongated sampling tube 3 and the sample gas bottle 5, and the gas sampling point is isolated from the gas pollution outside the sampling point. The micro gas sampling operation through the sampling tube 3 ensures that the obtained gas comes from a small area near the sampling point within a short time, and ensures the accuracy of the sampling. By adjusting the sampling tube 3, the depth in the same anode gas channel can be changed arbitrarily, and the sampling tube 3 in different anode gas channels is changed, so as to realize the multi-point grid sampling / temperature measurement. The present application combines the temperature measurement function with the internal gas sampling, and realizes the monitoring of the internal working condition of the flat tube fuel cell 1.

[0051] It should be noted that in the present specification, the relationship terms such as first and second are only used to distinguish one entity from another entity, and do not necessarily require or imply any such actual relationship or order between the entities.

[0052] The internal working condition detection method of the flat tube fuel cell provided by the present application is described in detail above. The principles and implementation modes of the present application are described by applying specific examples in this paper, and the above description of the examples is only used to help understand the method of the present application and its core idea. It should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, the present application can be improved and modified in several ways, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A method for detecting an internal state of a planar fuel cell, characterized by, The method comprises the following steps: Clamping and fixing the flat tube fuel cell along its two ends; Inserting a sampling tube through the clamp of either end into the anode gas passage of the flat tube fuel cell; Adjusting the position of the sampling tube to take multiple-point samples; Analyzing the composition of all the sampled gas and establishing the concentration field of the gas composition; The clamp is in the shape of a n-shaped, and the inner side of the two side walls of the n-shaped clamp is provided with a limiting step, so that the end of the flat tube fuel cell is clamped against the limiting step, forming a cavity between the clamp and the end of the flat tube fuel cell; one of the clamps at the two ends of the flat tube fuel cell is provided with an anode gas inlet hole, and the other is provided with an anode gas outlet hole, both of which are in communication with the cavity of the corresponding clamp, achieving uniform gas inlet and outlet; and either of the clamps at the two ends is provided with a detection hole in communication with the cavity, and a positioning sleeve is also provided at the detection hole to position the detection device of the sampling tube inserted into the cell, and the positioning sleeve and the clamp are screwed together; the outer diameter of the sampling tube is less than or equal to 1 / 3 of the inner diameter of the anode gas passage.

2. The method of claim 1, wherein The method further comprises the following steps: Inserting a temperature measuring probe through the clamp into the anode gas passage; Adjusting the position of the temperature measuring probe to take multiple-point temperature measurements; Establishing the temperature field inside the flat tube fuel cell according to the temperature data of the multiple-point temperature measurements.

3. The method of claim 2, wherein The outer diameter of the temperature measuring probe is less than or equal to 1 / 3 of the inner diameter of the anode gas passage.

4. The method of claim 1, wherein The steps of adjusting the position of the sampling tube to take multiple-point samples and analyzing the composition of all the sampled gas and establishing the concentration field of the gas composition further comprise drying the sampled gas and introducing the dried sampled gas into a sealed container.

5. The method of claim 4, wherein The step of analyzing the composition of all the sampled gas and establishing the concentration field of the gas composition comprises using a chromatographic sampling needle to extract the sampled gas in the sealed container and inject it into a chromatographic analyzer for chromatographic analysis, and determining the gas composition and proportion according to the chromatographic analysis results.

6. The method of claim 2, wherein The step of adjusting the position of the temperature measuring probe to take multiple-point temperature measurements is to adjust the temperature measurement position of the temperature measuring probe to coincide with the sampling position.

7. The method of claim 4, wherein the method further comprises: The method further comprises the following step before the step of adjusting the position of the sampling tube to take multiple-point samples: discharging the original atmosphere in the sealed container and the sampling tube.

Images