JP2002334713A - Fluid leak inspecting method for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid leak inspecting method for fuel cells capable of determining from which fluid passage to which fluid passage or from which fluid passage to the exterior a fluid leaks. SOLUTION: According to this fluid leak inspecting method for a fuel cell 10, an inspection fluid, such as gaseous helium, is sequentially injected into fluid passages 27, 28, and 26, for a fuel gas, oxidation gas, and a coolant, respectively, used for the fuel cell 10 and a leak of the inspection fluid is detected each time the inspection fluid is injected into the respective passages. A process for detecting a leak from a hydrogen chamber 27 is divided into a process for detecting a leak into an oxygen chamber 28 and a process for detecting a leak into portions other than the oxygen chamber 28. The process for detecting a leak into the oxygen chamber 28 is carried out prior to the process for detecting a leak into the portions other than the oxygen chamber 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell, and more particularly, to a fuel gas, an oxidizing gas,
The present invention relates to a method for detecting fluid leakage of a fuel cell, which detects leakage of each fluid of a refrigerant.

[0002]

2. Description of the Related Art A solid polymer electrolyte fuel cell comprises an electrolyte membrane comprising an ion exchange membrane, electrodes (anode and fuel electrode) comprising a catalyst layer and a diffusion layer disposed on one surface of the electrolyte membrane, and an electrolyte membrane. Membrane consisting of catalyst layer and diffusion layer electrodes (cathode, air electrode) arranged on the surface
Electrode assembly (MEA: Membrane-Electrode Assem
bly) and a separator that forms a fluid passage for supplying fuel gas (hydrogen) and oxidizing gas (oxygen, usually air) to the anode and cathode, and a plurality of cells are stacked to form a module. A module is formed by stacking the modules, and a terminal, an insulator, and an end plate are arranged at both ends of the module group in the cell stacking direction to form a stack. It is fixed by a fastening member (for example, a tension plate) extending in the cell stacking direction. In a solid polymer electrolyte fuel cell, on the anode side, a reaction is performed to convert hydrogen into hydrogen ions and electrons. The hydrogen ions move through the electrolyte membrane to the cathode side, and oxygen, hydrogen ions and electrons (neighboring atoms) move on the cathode side. ME
(Electrons generated at the anode of A pass through the separator) to produce water. Anode side: H ₂ → 2H ⁺ + 2e ⁻ Cathode side: 2H ⁺ + 2e ⁻ + (１ ／) O ₂ → H ₂ O To cool the Joule heat and the heat generated in the water generation reaction at the cathode, a space between the separators is used. In each of the cells, a coolant flow path through which a cooling medium (normally, cooling water) flows is formed for each cell or for each of a plurality of cells, thereby cooling the fuel cell.
Further, the fuel gas flow path, the oxidizing gas flow path, and the refrigerant flow path are sealed from each other and from the outside. During the assembly process and at the stage when the fuel cell becomes a product, the seal of the fuel gas passage, the oxidizing gas passage, and the coolant passage is inspected for quality. Japanese Patent Laying-Open No. 5-205762 discloses an evaluation device capable of detecting gas leakage of a single cell of a fuel cell and evaluating sealing characteristics. Here, nitrogen gas is supplied to the fuel gas flow path and the reaction air gas flow path and a differential pressure is applied to detect a gas flow rate flowing from the fuel gas flow path to the reaction air gas flow path.

[0003]

However, originally, the fuel gas flow path, the oxidizing gas flow path, and the refrigerant flow path, or the fuel gas flow path, the oxidizing gas flow path, the refrigerant flow path, and the external However, in the case of the above-described conventional method, it is possible to detect only gas leakage from the fuel gas flow path to the oxidizing gas flow path, regardless of whether the fluid leakage must be inspected. Even if it is applied to the fluid flow path at the same time, there is a problem that it is not possible to judge which flow path is leaking from which flow path or from which flow path to the outside. I don't know what to do. If there is a difference in the detected value between the fluid flow paths or the detected value from each fluid flow path to the outside, the leakage amount is small (for example, the refrigerant flow from one of the fuel gas flow path and the oxidizing gas flow path). The detected value of the leakage to the road and the outside is included in the error range of the detection value of the large leakage amount (for example, leakage from one of the fuel gas passage and the oxidizing gas passage to the other). There is also a problem that it is difficult to accurately detect small leaks. An object of the present invention is to inspect fluid leakage between a fuel gas passage, an oxidizing gas passage, a refrigerant passage, and the outside, and from any fluid passage to any fluid passage or from any fluid passage to the outside. Another object of the present invention is to provide a method for inspecting fluid leakage of a fuel cell, which can determine whether or not the fluid leaks. Another object of the present invention is to provide a fuel cell fluid leakage inspection method capable of accurately detecting each leakage amount even if there is a difference in leakage amount between the fluid flow paths, in addition to the above object. To provide.

[0004]

The present invention to achieve the above object is as follows. (1) Inject a test fluid into each fluid flow path of fuel gas, oxidizing gas, and refrigerant used in the fuel cell in order,
A fluid leakage inspection method for a fuel cell, which detects leakage of a test fluid at each injection time of each test fluid. (2) detecting the leakage from one of the fuel gas flow channel and the oxidizing gas fluid flow channel among the fuel gas, oxidizing gas, and refrigerant fluid flow channels; A step of detecting leakage from one of the fluid flow path of the fuel gas and the fluid flow path of the oxidizing gas to the other fluid flow path; and (1) The method for detecting fluid leakage in a fuel cell according to (1), wherein the method includes detecting a leakage from one of the fluid flow paths to the refrigerant flow path and the outside. (3) The step of detecting leakage from one of the fluid flow path of the fuel gas and the fluid flow path of the oxidizing gas to the other fluid flow path includes the steps of: (2) The method for inspecting fluid leakage of a fuel cell according to (2), which is performed prior to the step of detecting leakage from one of the gas fluid passages to the refrigerant passage and the outside.

In the fluid leakage inspection method for a fuel cell of the above (1), the inspection fluid is injected into each of the fluid flow paths of the fuel gas, the oxidizing gas, and the refrigerant in order, and the inspection is performed at each injection time of each inspection fluid. Since fluid leakage is detected, fluid leakage between the fuel gas flow path, oxidizing gas flow path, refrigerant flow path, and the outside can be inspected, and which fluid flow path to which fluid flow path or which fluid flow path It is possible to determine whether there is leakage from the road to the outside.
In the fluid leakage inspection method for a fuel cell according to the above (2), the step of detecting leakage from one of the fluid flow path of the fuel gas and the fluid flow path of the oxidizing gas includes the step of detecting the leakage of the fuel gas. A step of detecting leakage from one of the flow path and the fluid flow path of the oxidizing gas to the other fluid flow path; and one of the flow path of the fuel gas and the flow path of the oxidizing gas And a step of detecting leakage from the fluid flow path to the refrigerant flow path and the outside, so that the flow path from either one of the fuel gas flow path and the oxidizing gas flow path to the other fluid flow path Despite the amount of leakage to the passage and the amount of leakage from either one of the fuel gas flow path and the oxidizing gas flow path to the refrigerant flow path and outside, It is possible to detect each leak with high accuracy without causing the small leak to be included in the error range of the large leak. Can. In the fluid leakage inspection method for a fuel cell according to the above (3), a step of detecting leakage from one of the fuel gas fluid passage and the oxidizing gas fluid passage to the other fluid passage. Is performed prior to the step of detecting leakage from the fluid flow path of either the fuel gas flow path or the oxidizing gas flow path to the refrigerant flow path and the outside, so that the fuel gas flow path By reducing the time for detecting leakage from one of the fluid flow paths of the gas and the oxidizing gas to the other fluid flow path, the amount of test gas adhering to the pipe is reduced, and fuel gas is reduced. In the process of detecting leakage from one of the fluid flow path of the oxidizing gas and the fluid flow path of the oxidizing gas to the refrigerant flow path and the outside, noise is less reduced, and the fuel gas flow path and the oxidizing gas Leakage from one of the gas flow paths to the refrigerant flow path and the outside While maintaining that the inspection can be performed with high accuracy, the amount of time required to detect leakage from either one of the fuel gas flow path and the oxidizing gas flow path to the other fluid flow path has been reduced. Time can be reduced.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for inspecting fluid leakage of a fuel cell according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 8 show a first embodiment of the present invention.
FIGS. 0 to 14 show a second embodiment of the present invention, and FIGS.
FIG. 16 is applicable to both Embodiment 1 and Embodiment 2 of the present invention. First, portions applicable to any of the embodiments of the present invention will be described. The fuel cell to which the method of the present invention is applied is a solid polymer electrolyte fuel cell 10. The fuel cell 10 of the present invention is mounted on, for example, a fuel cell vehicle. However, it may be used other than a car.

A solid polymer electrolyte fuel cell 10 is shown in FIG.
5. As shown in FIG. 16, an electrolyte membrane 11 composed of an ion exchange membrane and a catalyst layer 1 disposed on one surface of the electrolyte membrane 11
Electrode 14 (anode, fuel electrode) composed of metal 2 and diffusion layer 13 and catalyst layer 15 arranged on the other surface of electrolyte membrane 11
-Electrode assembly (MEA: Membra) composed of a diffusion layer 16 and an electrode 17 (cathode, air electrode)
ne-Electrode Assembly) and reaction gas passages 27 and 28 (fuel gas passage 2) for supplying fuel gas (hydrogen) and oxidizing gas (oxygen, usually air) to the electrodes 14 and 17.
7, an oxidizing gas flow path 28) and a separator 18 forming a refrigerant flow path 26 through which a fuel cell cooling refrigerant (cooling water) flows, to form a cell, and a plurality of the cells are stacked to form a module 19; Modules 19 are stacked to form a module group, and terminals 20, insulators 21, and end plates 22 are arranged at both ends of the module 19 group in the cell stacking direction (fuel cell stacking direction) to form a stack 23. It consists of a fastening member 24 (for example, a tension plate) that extends in the cell stacking direction outside the cell stack and is fixed with bolts 25 in the cell stacking direction. The fuel gas passage 27, the oxidizing gas passage 28, and the refrigerant passage 26 each constitute a fluid passage.

The separator 18 comprises a fuel gas and an oxidizing gas,
Either the fuel gas or the cooling water or the oxidizing gas and the cooling water is partitioned, and an electric passage for electrons to flow from the anode to the cathode of an adjacent cell is formed. Refrigerant channel 26
Is provided for each cell or for a plurality of cells (for example, for each module). For example, one coolant channel 26 is provided for every two cells. The separator 18 is formed by forming a refrigerant channel 26, a fuel gas channel 27, and an oxidizing gas channel 28 on a carbon plate, or an uneven portion forming the refrigerant channel 26, the fuel gas channel 27, and the oxidizing gas channel 28. A plurality of superposed metal plates, or a resin plate mixed with conductive particles and made conductive to form a refrigerant channel 26, a fuel gas channel 27, and an oxidizing gas channel 28; And so on. Fuel gas passage 27, oxidizing gas passage 2
8. The coolant passage 26 must be sealed from each and from the outside. The sealing properties are determined during the fuel cell assembly stage (single cell stage, module stage,
Etc.) and at the time of assembly completion (stack stage).

A portion common to the first and second embodiments of the method for inspecting fluid leakage of a fuel cell according to the present invention will be described with reference to, for example, FIGS. FIG. 1 is a flowchart showing steps of a method for inspecting fluid leakage of a fuel cell according to the present invention.
FIG. 2 shows a system for inspecting the leakage of the fluid of the fuel cell, and FIGS. 3 to 8 show the flow paths of the respective fluid passages in the respective steps of the method of inspecting the leakage of the fluid shown in FIG. This shows the inspection state. As shown in FIGS. 1 and 2, the fluid leakage inspection method for a fuel cell according to the embodiment of the present invention is performed on the fuel gas flow path 27, the oxidizing gas flow path 28, and the refrigerant flow path 26 in order. The method comprises a fluid leak inspection method for injecting a test fluid and detecting a leak of the test fluid at each injection time of the test fluid. The test fluid is a gas that can be detected by a detector, such as helium, when the fluid flow path is evacuated, the test fluid is injected into the fluid flow path, and the test fluid leaking from the fluid flow path is detected by the detector. , Argon gas, hydrogen, and the like. When a method is used in which a pressure is applied to the fluid flow path to detect a pressure that decreases with the passage of time, any gas (for example, nitrogen or air) may be used. In the following description, an example is given in which the helium gas is injected as a test fluid into the fluid flow path under a vacuum, and the helium gas leaking from the fluid flow path is detected by a helium detector. However, it is not limited to this.

The test fluid may be injected into the fluid flow paths 27, 28, 26 in any order. FIG. 1 shows a case where the fuel gas flow path 27, the oxygen gas flow path 28, and the refrigerant flow path 26 are arranged in this order. However, the order may be the oxygen gas flow path 28, the fuel gas flow path 27, and the refrigerant flow path 26, or may be the refrigerant flow path 26, the fuel gas flow path 27, the oxygen gas flow path 28, or the refrigerant flow path. 26, oxygen gas passage 28,
The order of the fuel gas flow path 27 may be used.

As shown in FIGS. 1 and 2, a fuel cell (in a single cell state, in a module state, or in a stack state) to be subjected to a leak test is placed in a chamber 29 in a leak test container. Then, the entire inside of the chamber is evacuated, and the oxygen gas flow path 28, the fuel gas flow path 27, and the refrigerant flow path 26 are evacuated, and the oxygen gas flow path 28, the fuel gas flow path 27, and the refrigerant flow path 26 are sequentially inspected. Fluids (for example, helium gas) are injected, and the test fluid leaking from them is detected by a detector (when the test fluid is helium gas, the detector is a helium detector) 30. The piping connecting each of the fluid flow paths 27, 28, 26 and the detector 30 includes:
A valve 31 for opening and closing the flow path is provided, and by selecting the opening and closing thereof, the fluid flow paths 27, 28, 26
Is selectively inspected for leakage. For the detection by the detector 30, the amount of leakage is quantitatively detected.

In FIGS. 1 to 8, each display indicates the following. “Hydrogen”: A chamber (fluid flow path) into which hydrogen (fuel gas) is injected “Oxygen”: A chamber (fluid flow path) into which oxygen (oxidizing gas) is injected “Cooling water”: A chamber (fluid) through which cooling water passes Flow path) "External": Outside the fuel cell to be leak-tested, inside the chamber "→": From ...

[0013] In the above-described method for inspecting fluid leakage of a fuel cell,
Fuel fluid, oxidizing gas, and respective fluid flow paths 26 of the refrigerant,
Inspection fluid (for example, helium gas) is sequentially injected into 27 and 28, and leakage of the inspection fluid is detected at each injection time of each inspection fluid, so that fuel gas flow path 27, oxidizing gas flow path 28, refrigerant Fluid leakage between the flow path 26 and the outside (chamber) 29 can be inspected, and from which fluid flow path to which fluid flow path or from which fluid flow path to the outside, the leakage amount You'll know how much and where to repair or what parts to replace. Also, or if leaks appear in many fuel cells, you will know where to change the design,
Repair, replacement, and design changes are much more efficient than before.

The examples of FIGS. 1 and 2 show the entire fluid flow path 2.
7, 28, 26 and the outside 29, one detector 30
In this case, the individual pipes are connected to the detector 30. However, as shown in FIG.
By providing the detector 30 in each of the pipes 8 and 26, it is possible to simultaneously determine leaks to each room or to the outside without switching valves, and it is possible to perform leak inspection more efficiently. FIG. 9 shows a case where the test gas is injected into the hydrogen chamber, but the injection of the test gas into each chamber in order is the same as in the example of FIG.

Next, parts unique to each embodiment of the present invention will be described. Embodiment 1 In the inspection method according to Embodiment 1 of the present invention, FIGS.
As shown in FIG. 9, in step 101 of FIG. 1, a test fluid (for example, helium gas) is injected into a hydrogen chamber (fuel gas flow path 27) to obtain the state of FIG. The leak to the passage 28), the cooling water chamber (the refrigerant passage 26), and the outside (the chamber 29) is inspected by the detector 30.
If no leakage is detected in step 101 (OK), it is determined that there is no leakage from the hydrogen chamber 27, and the process proceeds to step 102.
It is further examined whether or not there is a leak from the oxygen chamber 28 and the cooling water chamber 26. If a leak is detected in step 101 (NG), it is determined that there is a leak from the hydrogen chamber to any of the oxygen chamber, the cooling water chamber, and the outside. Consider further.

In step 102, the hydrogen chamber (fuel gas flow path 2)
7) While the helium gas is being filled, the helium gas is further injected into the oxygen chamber (oxidizing gas flow path 28) to obtain the state shown in FIG. 4, and the cooling water chamber (refrigerant flow path 29) and the outside (chamber 2)
9) The leakage to the detector 30 is inspected by the detector 30. Step 1
02, if no leakage is detected (OK), the hydrogen chamber
Since there is no leakage from the oxygen chamber, the process proceeds to step 103, and it is further examined whether or not there is leakage from the cooling chamber. Step 1
If a leak is detected at 02 (NG), it is determined that there is a leak from the oxygen chamber to the cooling water chamber or to the outside, and the process proceeds to step 106 to further examine where the leak has occurred. .

In step 103, the hydrogen chamber (fuel gas passage 2)
7) While the helium gas is being filled in the oxygen chamber (oxidizing gas flow path 28), helium gas is further injected into the cooling water chamber (refrigerant flow path 29) to obtain the state shown in FIG.
9) The leakage to the detector 30 is inspected by the detector 30. Step 1
03, if no leakage is detected (OK), the hydrogen chamber
The test passed since there was no leakage from the oxygen chamber and cooling water chamber. If a leak is detected in step 103 (NG),
It is determined that there is leakage from the cooling water chamber to the outside. In this case, the gas amount is detected, and if the gas amount is equal to or larger than the allowable value, the leaked portion from the cooling water chamber to the outside is repaired or the defective portion is replaced.

In step 104, the hydrogen chamber (fuel gas flow path 2)
Since it is already known that there is a leak from 7), it is checked whether there is any leak from the hydrogen chamber to the oxygen chamber, the cooling water chamber, or the outside. Therefore, without injecting the inspection gas into the oxygen chamber, the pipe connecting the oxygen chamber (oxidizing gas flow path 28) and the detector 30 is opened to determine whether the oxygen chamber has a helium gas leak from the hydrogen chamber. To inspect. Step 10
If it is determined in Step 4 that helium gas leaks into the oxygen chamber (NG), it is determined that the gas leaks from the hydrogen chamber to the oxygen chamber, and the leak path (for example, a hole is formed in the electrolyte membrane). Repair) or replace the defective part. If it is determined in step 104 that the helium gas does not leak to the oxygen chamber (OK), the process proceeds to step 105,
Further, it is inspected whether the hydrogen chamber is leaked into the cooling water chamber or the outside.

In step 105, the hydrogen chamber (fuel gas flow path 2)
Since it is already known that there is a leak from 7) and that there is no leak from the oxygen chamber (oxidizing gas flow path 28), the hydrogen chamber leaks into either the cooling water chamber or the outside. Inspect whether or not. Therefore, without injecting the inspection gas into the oxygen chamber and the cooling water chamber, the pipe connecting the cooling water chamber (the refrigerant flow path 26) and the detector 30 is opened, and the helium gas leaks from the hydrogen chamber into the cooling water chamber. Check if there are any.
If it is determined in step 105 that the helium gas leaks to the cooling water chamber (NG), it is determined that the gas leaks from the hydrogen chamber to the cooling water chamber, and the leak path is repaired.
Replace defective part. If it is determined in step 105 that the helium gas does not leak into the cooling water chamber (OK), it is determined that the gas leaks from the hydrogen chamber to the outside, and the leak is repaired or the defective part is replaced.

In step 106, since it is already known that there is no leakage from the hydrogen chamber and that there is leakage from the oxygen chamber, the oxygen chamber has leaked to either the cooling water chamber or the outside. Inspect whether or not. Therefore, without injecting the test gas into the cooling water chamber, the pipe connecting the cooling water chamber (refrigerant flow path 26) and the detector 30 is opened to check whether there is a leak of helium gas from the oxygen chamber in the cooling water chamber. Check for no. If it is determined in step 106 that the helium gas leaks into the cooling water chamber (NG), it is determined that the gas leaks from the oxygen chamber to the cooling water chamber, and the leak path is repaired or a defective portion is removed. replace. When it is determined that there is no helium gas leak to the cooling water chamber in step 106 (OK)
Determines that the gas leaks from the oxygen chamber to the outside, and repairs the leaked part or replaces the defective part. This completes the leak inspection of all the fluid flow paths, knows where the leak is from, where the leak is and how much it should be repaired, or what parts should be replaced I understand.

[Embodiment 2] The method of Embodiment 2 of the present invention is a further improvement of the method of Embodiment 1 of the present invention. The following problem still remains in the method of the first embodiment of the present invention. Since the amount of gas permeated from the hydrogen chamber 27 to the oxygen chamber 28 separated by the electrolyte membrane 11, which is a gas permeable membrane, is larger than other leaked values, the gas permeated from the hydrogen chamber 27 to the cooling water chamber 2
6. It is difficult to find leaks to the outside 29. If the amount of leak from the oxygen chamber 28 is detected after the amount of leak from the hydrogen chamber 27 having a large detection value is detected, a lot of noise is spread and the detection time is long. In the second embodiment of the present invention, while maintaining the object of the first embodiment of the present invention, the problem of the first embodiment of the present invention, that is, the hydrogen chamber 27
It is an object of the present invention to provide a method for inspecting fluid leakage of a fuel cell, which can detect a leak from the fuel cell to the cooling water chamber 26 and the outside 29 with high accuracy and can shorten the detection time.

The method for inspecting fluid leakage of a fuel cell according to the second embodiment of the present invention is the same as the method of the first embodiment of the present invention, except that the fluid flow paths 27, 28,
The step of detecting leakage from any one of the fuel gas flow path 27 and the oxidizing gas flow path 28 (e.g., the fuel gas flow path 27) in FIGS.
As shown in FIG. 7, one of the fuel gas flow path 27 and the oxidizing gas flow path 28 (for example, the fuel gas flow path 27) is connected to the other fluid flow path (for example, the oxidizing gas flow path). 28), a step 201 for detecting leakage to the refrigerant flow path 27 (for example, the fuel gas flow path 27) and the refrigerant flow path 26 And a step 202 of detecting a leak to the outside 29.

In the fluid leakage inspection method for a fuel cell according to the second embodiment of the present invention, the fuel gas
20: detecting leakage from one of the fluid flow paths (for example, the fuel gas flow path 27) of the fluid flow path 28 of the oxidizing gas to the other fluid flow path (for example, the oxidizing gas flow path 28).
1 is a flow path 27 for the fuel gas and a flow path 2 for the oxidizing gas.
8 (for example, the fuel gas passage 2
7) is performed prior to the step 202 of detecting leakage to the refrigerant flow path 26 and the outside 29. Others are the same as in the first embodiment of the present invention.

More specifically, in the fluid leakage inspection method for a fuel cell according to the second embodiment of the present invention, in step 201, as shown in FIG. The amount of gas permeated into the chamber 28 is output quantitatively. Since the gas permeation amount shows a larger detection value than the other leak amounts, the gas adheres to the pipe and causes measurement noise in the next process, so that the detection in the process 201 is performed in a short time. When the detection value is smaller than the predetermined standard value and the result is OK, the process proceeds to step 202. When the result of the process 201 is NG, the leak NG from the hydrogen chamber 27 to the oxygen chamber 28 or the electrolyte An NG determination is made on the assumption that there is some defect due to deterioration of the film 11 or the like.

In step 202, as shown in FIG. 12, while the inspection gas is sealed in the hydrogen chamber 27, the amount of the inspection gas detected from the cooling water chamber 26 and the outside (chamber) 29 is quantitatively detected. In step 202, the amount of leakage from the hydrogen chamber 27 to the cooling water chamber 26 and the outside (chamber) 29 is monitored.
03, and if an NG determination is made, the process proceeds to step 205.

In step 203, as shown in FIG. 13, gas is sealed not only in the hydrogen chamber 27 but also in the oxygen chamber 28, and the amount of gas detected from the cooling water chamber 26 and the outside (chamber) 29 is detected. In step 203, the amount of leakage from the oxygen chamber 28 is monitored, and if an OK determination is made with respect to the standard, the process proceeds to step 204. If an NG decision is made, step 20
Move to 6.

In step 204, as shown in FIG. 14, gas is sealed not only in the hydrogen chamber 27 and the oxygen chamber 28 but also in the cooling water chamber 26, and the amount of gas detected from the outside (chamber) 29 is detected. In step 204, the amount of leakage from the cooling water chamber 26 is monitored, and if OK is determined for the standard, it is determined to be acceptable. If an NG determination is made, the cooling water chamber 2
It is determined that leak NG from 6 to the outside 29 has occurred.

In step 205, since the leak NG from the hydrogen chamber 27 has been determined, it is a step of determining which chamber 28, 26 or the outside 29 is leaking.
Since this is a process of specifying a leaked portion, whether or not to adopt the mass production due to a problem such as cycle time can be determined by a user's judgment. In step 206, the oxygen chamber 28
Room 26 because the leak NG from
Alternatively, it is a step of determining whether or not leakage has occurred to the outside 29. Since this is a process of specifying a leaked portion, whether or not to adopt the mass production due to a problem such as cycle time can be determined by a user's judgment. Through the above inspection process, not only can the deterioration and loss of the electrolyte membrane 11 due to the magnitude of the gas permeation amount be determined, but also the leakage to the outside from each chamber, which should never be present, is not overlooked. It can be determined by the detector, and an inexpensive and efficient leak test can be performed.

[0029]

According to the first aspect of the present invention, the test fluid is injected into each of the fluid flow paths of the fuel gas, the oxidizing gas, and the refrigerant in order, and the injection time of each test fluid is determined. Since the leak of the test fluid is detected every time, the fluid leak between the fuel gas channel, the oxidizing gas channel, the coolant channel, and the outside can be inspected, and from which fluid channel to which fluid channel, or It is possible to determine which fluid flow path is leaking to the outside. According to the fluid leakage inspection method for a fuel cell according to claim 2,
The step of detecting leakage from any one of the fluid flow path of the fuel gas and the fluid flow path of the oxidizing gas includes the step of detecting any one of the fluid flow path of the fuel gas and the oxidizing gas. A step of detecting leakage from the flow path to the other fluid flow path, and leakage from one of the fuel flow path and the oxidizing gas flow path to the refrigerant flow path and the outside. The leakage flow from one of the fuel gas flow path and the oxidizing gas flow path to the other fluid flow path and the fuel gas flow path Despite the magnitude of the leakage from either one of the fluid flow paths of the gas to the refrigerant flow path and the amount of leakage to the outside, the leakage of the leakage is small. Each leak can be accurately detected without being included in these error ranges. According to the fluid leakage inspection method for a fuel cell according to the third aspect, leakage from one of the fluid flow path of the fuel gas and the fluid flow path of the oxidizing gas to the other fluid flow path is detected. Since the step is performed prior to the step of detecting leakage from either one of the fuel gas flow path and the oxidizing gas flow path to the refrigerant flow path and the outside, the fuel gas flow path By reducing the time for detecting leakage from one of the flow path and the fluid flow path of the oxidizing gas to the other fluid flow path, the amount of test gas adhering to the piping is reduced, In the step of detecting leakage from the fluid flow path of the gas and the flow path of the oxidizing gas to the refrigerant flow path and the outside, less noise is generated, and the flow path of the fuel gas and the flow path of the fuel gas are reduced. Leakage from one of the oxidizing gas fluid channels to the coolant channel and the outside While maintaining that it can be inspected with high accuracy, the amount of time required to detect leakage from any one of the fuel gas fluid channel and the oxidizing gas fluid channel to the other fluid channel is reduced, Inspection time can be reduced.

[Brief description of the drawings]

FIG. 1 is a flowchart showing steps of a method for inspecting fluid leakage of a fuel cell according to Embodiment 1 of the present invention.

FIG. 2 is a system diagram of an apparatus for performing a method for inspecting fluid leakage of a fuel cell according to Embodiment 1 of the present invention.

FIG. 3 is a system diagram showing a test gas injection state of each chamber and a state of communication with a detector in step 101 of FIG. 1;

FIG. 4 is a system diagram showing a test gas injection state of each chamber and a state of communication with a detector in a step 102 of FIG. 1;

FIG. 5 is a system diagram showing a test gas injection state of each chamber and a state of communication with a detector in step 103 of FIG. 1;

FIG. 6 is a system diagram showing an inspection gas injection state of each chamber and a state of communication with a detector in step 104 of FIG. 1;

FIG. 7 is a system diagram showing a test gas injection state of each chamber and a state of communication with a detector in step 105 of FIG. 1;

FIG. 8 is a system diagram showing a test gas injection state of each chamber and a state of communication with a detector in step 106 of FIG. 1;

FIG. 9 is a system diagram of another apparatus for performing the fluid leakage inspection method for the fuel cell according to the first and second embodiments of the present invention.

FIG. 10 is a flowchart showing steps of a method for inspecting fluid leakage of a fuel cell according to Embodiment 2 of the present invention.

11 is a system diagram showing a state of injection of a test gas into each chamber and a state of communication with a detector in step 201 of FIG.

FIG. 12 is a system diagram showing a test gas injection state of each chamber and a state of communication with a detector in step 202 of FIG. 10;

FIG. 13 is a system diagram showing a test gas injection state of each chamber and a communication state to a detector in step 203 of FIG.

FIG. 14 is a system diagram showing a test gas injection state of each chamber and a state of communication with a detector in step 204 of FIG. 10;

FIG. 15 is an overall schematic view of a fuel cell to which the method for inspecting fluid leakage of a fuel cell according to the present invention is applied.

16 is a partially enlarged cross-sectional view of the fuel cell of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 (Solid polymer electrolyte type) fuel cell 11 Electrolyte membrane 12 Catalyst layer 13 Diffusion layer 14 Electrode (anode, fuel electrode) 15 Catalyst layer 16 Diffusion layer 17 Electrode (cathode, air electrode) 18 Separator 19 Module 20 Terminal 21 Insulator 22 End plate 23 Stack 24 Tension plate 25 Bolt 26 Cooling water flow path (Cooling water chamber) 27 Fuel gas flow path (Fuel gas chamber) 28 Oxidizing gas flow path (Oxidizing gas chamber) 29 Chamber 30 Detectors 101, 102, 103, 104, 105, 106 Steps of Example 1 201, 202, 203, 204, 205, 206 Steps of Example 2

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Naoyuki Maruta 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Masayasu Taguchi 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F Terms (reference) 5H026 AA06 5H027 AA06 KK00 KK31

Claims (3)

[Claims] 1. A fuel for injecting a test fluid into respective fluid flow paths of a fuel gas, an oxidizing gas, and a refrigerant used in a fuel cell in order, and detecting leakage of the test fluid at each injection time of the test fluid. Battery fluid leakage inspection method. 2. A step of detecting leakage from one of the fuel gas flow channel and the oxidizing gas fluid flow channel among the fuel gas, oxidizing gas, and refrigerant fluid flow channels. Detecting a leak from one of the fluid flow path of the fuel gas and the fluid flow path of the oxidizing gas to the other fluid flow path; and 2. The method for inspecting fluid leakage of a fuel cell according to claim 1, wherein the method further comprises a step of detecting leakage from one of the fluid passages to the coolant passage and the outside. 3. The step of detecting leakage from one of the fuel gas flow path and the oxidizing gas flow path to the other of the fuel gas flow path and the fuel gas flow path. 3. The method for inspecting fluid leakage of a fuel cell according to claim 2, wherein the method is carried out prior to the step of detecting leakage from one of the fluid flow paths of the gas and the oxidizing gas to the refrigerant flow path and the outside.