KR100588507B1 - Apparatus for checking damaged cell in the fuel cell stack - Google Patents

Abstract

Disclosed is a broken cell detector for a fuel cell stack. The broken cell detection apparatus of the disclosed fuel cell stack includes a fuel cell stack including a plurality of sanitary fittings and a manifold; A gas cylinder connected through the fuel cell stack and a gas line; A sensor installed at one side of the fuel cell stack to detect a gas leaking from the fuel cell stack; A gas detector connected to the sensor and quantitatively indicating the amount of gas read by the sensor; And a position indicator needle installed at one side of the sensor to indicate a position of the separator to be repaired among the separators of the fuel cell stack when a gas leaks.

According to the present invention, it is possible to find the damaged part of the fuel cell stack by one measurement without repeatedly dismantling and refastening the fuel cell stack, thereby saving work time, minimizing human resources, and several fuel cell cycles. It can minimize the damage of MEA that occurs during stack disassembly, which contributes to cost reduction, and there is no repetitive fuel cell stack disassembly and refastening, which can eliminate the performance reduction caused by shrinkage / relaxation stress of MEA / GDM. .

Fuel Cell Stack, Separator, Gas Detector

Description

Damage cell detection device of fuel cell stack {APPARATUS FOR CHECKING DAMAGED CELL IN THE FUEL CELL STACK}

1 is a block diagram of a typical fuel cell stack.

2a and 2b is a schematic view showing an airtight test apparatus of a fuel cell stack according to the prior art.

3 is a schematic view of a broken cell detection procedure in a fuel cell stack according to the prior art;

Figure 4 is a schematic view showing the configuration of a broken cell detection device of a fuel cell stack according to the present invention.

5 is a view showing the precise measurement of the sensor of Figure 4;

<Description of the symbols for the main parts of the drawings>

30. Fuel Cell Stack

36. Separator

40. Gas Cylinder

50. The Frame

51.Sensor

52. Gas Detector

53. Placemark Needle

54. Up and down dial

60. Stand

70. Precise measurement

The present invention relates to a broken cell detection apparatus of a fuel cell stack, and more particularly, to minimize fuel cell stack performance and fuel cell stack airtightness evaluation by minimizing shrinkage / relaxation stress, thereby improving fuel cell stack repair process. The present invention relates to a broken cell detection device of a fuel cell stack for reducing cost and achieving cost reduction.

The fuel cell is composed of an electrode that causes an electrochemical reaction, and an electrolyte membrane that delivers hydrogen ions generated by the reaction, and a separator that supports the electrode and the electrolyte. The polymer electrolyte fuel cell has the advantages of high efficiency, high current density, high output density, short start-up time, and solid electrolyte, compared with other types of fuel cells, and thus do not require corrosion and electrolyte control.

In addition, since it is an environmentally friendly power source that emits pure water only as exhaust gas, active research is being conducted in the global automotive industry.

The polymer electrolyte fuel cell is a device that generates electricity while generating water and heat through an electrochemical reaction between hydrogen and oxygen. The supplied hydrogen is separated into hydrogen ions and electrons in the catalyst of the anode electrode, and the separated hydrogen ions are transferred to the cathode through the electrolyte membrane, whereupon the combined oxygen and electrons from the external conductor are combined. To generate water while generating electrical energy. The theoretical potential generated is about 1.3V and the reaction is as follows.

Anode: H2-> 2H + + 2e

Cathode: 1/2 O2 + 2H + + 2e-> H2O

In actual automotive fuel cells, a potential higher than that shown above is required. In order to obtain a higher potential, individual unit cells must be stacked as needed. This stacking is called a fuel cell stack, and a schematic diagram of the fuel cell stack is shown in FIG. 1.

As shown in FIG. 1, such a fuel cell is composed of an end plate 11, a graphite separator plate 12, a gasket, and a membrane-electrode assembly (MEA) 13. The fuel cell stack 10 is completed by fastening using the fastening band 14.

In order to operate the fuel cell stack 10 in a stable manner, an anode through which hydrogen flows, a cathode through which air flows, and a coolant through which coolant flows must be completely independent. After the fuel cell stack 10 is fabricated, airtightness tests are performed to check whether each part is completely independent. If gas leaks from one part to another, or the fuel cell stack 10 is externally When the gas leaks, it is necessary to find the MEA 13 or the separator 12 that is not airtight by unpacking the manufactured fuel cell stack 10 and replacing it with a new component.

2A and 2B show an existing fuel cell stack 10 leak tight test apparatus.

In particular, FIG. 2A is an exterior airtight test device, and FIG. 2B is a crossover airtight test device. When the airtight test of the fuel cell stack 10 fastened at a constant pressure by using a fastening mechanism such as a fastening bolt or an end plate 11, firstly, the outer airtight is inside the fuel cell stack 10 (Anode, Cathode, Air is injected into the cylinder 16 through a sanitary fitting 15 connected to a coolant at a constant pressure of about 30 psi, and then the separator plate 12 or a gasket between the separator plates 12 and the MEA. It is determined whether the airtightness by checking whether the gas leaks to the (13) part.

When the separator 12 and the MEA 13 are damaged from the beginning, and the gasket, MEA 13, and GDM that are broken while the separator 12 is fastened or entered between the separator 12 are correct, When not in position, the gas leaks to the outer portion of the fuel cell stack 10, and the gas pressure drops through the cylinder 16 gas regulator, but by spraying a snoop liquid on the outside of the fuel cell stack 10, You can find it. This external confidentiality assessment is easily done at once, so that damaged parts can be easily found.

Secondly, crossover tightness is achieved by injecting air at a pressure of several psi into only one of the three parts of the anode, cathode and coolant and measuring the amount of gas leaking into the rest. If airtight is not maintained, the amount of leaking gas is typically a few ml per minute and is measured using a bubble flowmeter 17 as shown in FIG. 2B. Gas leaks may occur due to pinholes due to defects in MEA manufacturing, cracks in the separator 12, and shifting of gaskets or GDMs during stacking.

If the sieve fuel cell stack 10 is operated without complete airtightness, hydrogen flowing to the anode and air flowing to the cathode may meet and react to generate a spark, which may damage the MEA 13 or the fuel cell stack 10. And leaking hydrogen gas to the outside may cause a dangerous situation.

The conventional crossover airtight test method is tested by several trial and error methods, as shown in FIG. 3. The procedure is as follows.

First, the fuel cell stack 10 fastened by the fastening band 14 is evaluated for external airtightness and crossover airtightness (step A). Replace only (Step B)

When the crossover airtightness is not maintained, the fuel cell stack 10 which is fastened is separated in half. (Step C) For example, in the case of 120 cells, the fuel cell stack 10 is divided into 60 cells. Thus, instead of the end plate 11 for the fuel cell stack 10 on the top of the first part divided in half, an airtight test end plate is placed and pressed using a press force equal to the fastening pressure of the conventional fuel cell stack 10. (Step D)

In addition, after connecting the sanitary fitting (15) attached to the end plate (11) with the air cylinder (16), it is measured whether the gas leaks to the cathode, coolant portion while inserting a few psi of air into the anode portion. Step E)

Subsequently, the cathode and the coolant portions are also subjected to the same method to determine whether it is airtight. (Step F) The remaining half of the portion (60 cells) is also performed in the same manner.

The gas leaked part (60 cells) is divided in half (30 cells) in the same manner as in Step C and subjected to airtight evaluation in the same manner as in Steps E and F. (Step H)

The above method is repeated until a gas leak is found (step I).

As such, the conventional method requires a lot of time and manual labor to repeat damaged tests of the same method in order to find damaged cells, which requires a lot of human resources and is not economical.

In addition, the MEA 13 is left in the air for a long time in the airtight test of the fuel cell stack 10 by dividing it in half. If the MEA 13 is contracted according to the indoor environmental conditions, the separation plate 12 may be reconnected. ) You will not be able to show the size and difference.

In addition, the compression / relaxation stress caused by repeated tightening and dismantling may damage the MEA (13) and the GDM, which may result in low performance when evaluating the performance after resampling.

The present invention was created in order to solve the above problems, and it is possible to find the damaged part of the fuel cell stack in one measurement, thereby preventing the fuel cell stack from being damaged due to shrinkage / relaxation stress of the MEA / GDM. Its purpose is to provide a cell detector.

Damage cell detection device of the fuel cell stack of the present invention for achieving the above object, a plurality of sanitary fittings, the fuel cell stack provided with a manifold; A gas cylinder connected through the fuel cell stack and a gas line; A sensor installed at one side of the fuel cell stack to detect a gas leaking from the fuel cell stack; A gas detector connected to the sensor and quantitatively indicating the amount of gas read by the sensor; And a position indicator needle installed at one side of the sensor to indicate a position of the separator to be repaired among the separators of the fuel cell stack when a gas leaks.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 4 is a schematic diagram showing the configuration of a broken cell detection device of a fuel cell stack according to the present invention.

Referring to the drawings, the broken cell detection device of the fuel cell stack according to the present invention, a plurality of sanitary fittings, such as anode / coolant / cathode sanitary fittings (31, 32, 33), and manifold (34, 35) ) Is provided with a fuel cell stack 30, a gas cylinder 40 connected through the fuel cell stack 30 and the gas line 41, and installed on one side of the fuel cell stack 30, the fuel cell stack A sensor 51 for detecting the gas leaking from the 30, a gas detector 52 connected to the sensor 51 and quantitatively indicating the amount of gas read from the sensor 51, and the sensor 51 Is installed on one side is configured to include a position indicator needle 53 to indicate the position of the separator 36 to be repaired in the separator 36 of the fuel cell stack 30 when the gas leaks.

The sensor 51, the gas detector 52, and the position indication needle 53 are installed in the frame 50 that is integrated. In addition, the frame 50 and the fuel cell stack 30 are fixed to the stand 60 installed at the bottom thereof.

In addition, the gas detector 52 is operated to move up and down by the vertical adjustment dial 54 installed on one side of the frame 50, the position display needle 53 is installed at the same height as the sensor 51.

In addition, the gas detector 52 and the sensor 51 are integrally provided, and the lower end of the sensor 51 is movable to the inside of the manifolds 34 and 35 of the fuel cell stack 30. 35).

In addition, the sensor 51 is provided with a precision measurement cover 70 to allow gas to flow into the sensor 51 so that the gas leakage can be measured more precisely. The precision measurement cover 70, the coupling port 71 for coupling the sensor 51 is formed on the upper side, the gas inlet so that the gas flows into the lower end in communication with the coupling port 71 ( 72 is formed, the coupler 71 and the gas inlet 72 is formed by bending at a predetermined angle.

On the other hand, the gas in the gas cylinder 40 that can be used in the present invention, can be detected by the gas detector 52 can use any one of helium, argon or a small amount of hydrogen of high safety during the experiment. .

Referring to the operation of the broken cell detection device of the fuel cell stack according to the present invention having the configuration as described above are as follows.

Referring again to the drawings, the broken cell detection device of the fuel cell stack according to the present invention, the gas tightness tester using the gas detector 52 and the fuel cell stack 30 using the same for evaluating the airtightness of the fuel cell stack (30). The repair procedure shows that the damaged portion of the fuel cell stack 30 is determined by one measurement without dismantling and re-closing the fuel cell stack 30 times compared to the conventional method of determining whether the fuel cell stack 30 is damaged or not. You can find it.

Therefore, the fuel cell stack 30 may not only be repaired, but also the MEA and GDM components of the fuel cell stack 30 may not be subjected to compression / relaxation stress due to repeated dismantling and refastening. 30) You can expect performance.

And when the airtight test of the fuel cell stack 30 completed through the assembly of the fastening mechanism by the conventional method, in the case of the outer confidential test it can be easily found in the damage site in one test.

This will be described in more detail.

The gas detector 52 quantitatively represents the amount of gas read from the sensor 51, and can be measured in ppm, and other gas detectors 52 may be used according to the type of gas used. In addition, the gas detector 52 is fixed to the stand 60 and can be moved freely up and down through the vertical adjustment dial (54).

And the position indicator needle 53 is disposed below the gas detector 52, which indicates the position of the separation plate 36 to be installed at the same height as the sensor 51 to be repaired in case of gas leakage. The sensor 51 provided at the end of the gas detector 52 can detect the gas used by being integrated with the gas detector 52.

In addition, the sensor 51 portion is smaller than the manifolds 34 and 35 of the fuel cell stack 30 and should be freely movable into the manifolds 34 and 35.

And, as shown in Figure 5 for the precise measurement of the leaking gas, the precision measurement cover 70 with a hole as the gas leakage portion can be attached to the sensor 51 portion.

On the other hand, there are generally six manifolds inside the fuel cell stack, two of which are diagonally connected. Each manifold is called an anode manifold, a cathode manifold, and a coolant manifold. In actual operation, hydrogen, air, and coolant flow into each part.

In the fuel cell stack airtight test, the gas cylinder 40 supplies a gas through a gas supply line to any one of three manifold parts, and detects whether the gas comes out to another part. In the present invention, the gas detector ( The detection of leaking gas is carried out through 52).

As shown in FIG. 4, when the gas line 41 is connected to the anode sanitary fitting 31 to supply gas to the anode manifold, the gas detector 52 fixed to the position measuring stand 60 is connected. By moving up and down within the other manifold, it is possible to check the damage state of the fuel cell stack 30 through gas detection. On the other hand, if the fuel cell stack 30 is not damaged, gas will not be detected through the gas detector 52.

However, if the fuel cell stack 30 is partially damaged, gas will leak and the alarm of the gas detector 52 will be displayed. At this time, if the sensor 51 is carefully operated up and down, it will show the highest amount of leakage in the damaged part, and the position indication needle 53 fixed to the position measuring stand 60 will remove the separator 36 or MEA. Will point.

When the gas is connected to the other manifolds 34 and 35 in the same manner and measured in the same manner, the damaged part of the fuel cell stack 30 can be easily found.

After finding the damaged portion in the fuel cell stack 30, the repair procedure of the fuel cell stack 30 is as follows.

First, after marking the broken portion, the fastening mechanism of the fuel cell stack 30 is released to relax the fuel cell stack 30 to remove the fastening mechanism. Then, the fuel cell stack 30 is lifted to just above the damaged portion, and the existing fuel cell stack 30 is divided into two. Subsequently, replace the broken parts with new MEA and separator 36 and then recombine the two parts again.

The fuel cell stack 30 thus recombined is reassembled using a fastening mechanism. The completed fuel cell stack 30 is airtight again.

As described above, the broken cell detection apparatus of the fuel cell stack according to the present invention has the following effects.                     

Fuel cell stack breakage can be found in one measurement without repeated disassembly and reassembly of fuel cell stacks, saving time.

And repeated fuel cell stack disassembly and refastening takes a lot of human resources, but the present invention can minimize the human resources because the measurement is made at a time.

In addition, it is possible to minimize the damage to the MEA that occurs when dismantling the fuel cell stack several times, thereby reducing the cost.

In addition, there is no repeated fuel cell stack disassembly and re-connection, eliminating the performance reduction caused by shrinkage / relaxation stress of MEA / GDM. That is, the performance of the fuel cell stack can be improved by minimizing shrinkage / relaxation stress.

In addition, convenience can be improved by simplifying the airtight evaluation work of the fuel cell stack, and the repair process of the fuel cell stack can be reduced.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent embodiments are possible. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

Claims (10)

A fuel cell stack having a plurality of sanitary fittings and a manifold; A gas cylinder connected through the fuel cell stack and a gas line; A sensor installed at one side of the fuel cell stack to detect a gas leaking from the fuel cell stack; A gas detector connected to the sensor and quantitatively indicating the amount of gas read by the sensor; And a position indicator needle installed at one side of the sensor to indicate a position of a separator to be repaired among the separators of the fuel cell stack when a gas leaks. The method of claim 1, And the sensor, the gas detector and the position indication needle are installed in an integrated frame. The method of claim 2, And the frame and the fuel cell stack are fixed to a stand installed at a bottom thereof. The method of claim 2, The gas detector is broken cell detection device of the fuel cell stack, characterized in that it is operated to move up and down by a vertical adjustment dial installed on one side of the frame. The method of claim 1, The position indicator needle is broken cell detection device of the fuel cell stack, characterized in that installed at the same height as the sensor. The method of claim 1, The gas detector and the sensor is broken cell detection device of the fuel cell stack, characterized in that provided integrally. The method of claim 1, The lower end of the sensor is broken cell detection device of the fuel cell stack, characterized in that formed smaller than the manifold to be able to move inside the manifold of the fuel cell stack. The method of claim 1, The sensor is broken cell detection device of the fuel cell stack, characterized in that the gas is introduced into the sensor to precisely measure the cover to measure the gas leakage more precisely. The method of claim 8, The precision measurement covered, A coupling hole for coupling the sensor is formed at the upper portion, and a gas inlet is formed so that gas is introduced into the lower end thereof so as to communicate with the coupling hole, and the coupling hole and the gas inlet are bent at a predetermined angle. Damage cell detection device of the fuel cell stack. The method of claim 1, The gas in the gas cylinder is any one of helium, argon, or a small amount of hydrogen, broken cell detection device of the fuel cell stack.

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