JP2006338978A - Evaluation method of flow of reactant gas in fuel cell, evaluation device, fuel cell for evaluation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an evaluation method of flow of a reactant gas in a fuel cell which enables to comprehend quantitative movement and flow distribution of gas in a separator surface, an evaluation device, and a fuel cell for evaluation. <P>SOLUTION: (1) The evaluation method of flow of a reactant gas in the fuel cell has a process of introducing an inspection gas from an inspection gas entrance 53 provided between an entrance 51 and an exit 52 of a normal reactant gas and a process of detecting a detection gas by a detection part 54 provided between the entrance and exit of the normal reactant gas. (2) The evaluation device 50 of flow of an reactant gas in the fuel cell has an inspection gas entrance 53 provided between the entrance and exit of the normal reactant gas and an inspection gas detection part 54 provided between the entrance and exit of the normal reactant gas, and an inspection gas measurement means 56 connected to it. (3) The fuel cell for evaluation 10T of flow of the reactant gas in the fuel cell has an inspection gas entrance 53 provided between the entrance and exit of the normal reactant gas and an inspection gas detection part 54 provided between the entrance and exit of the normal reactant gas. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for evaluating the flow of a reaction gas in a fuel cell, an evaluation device used directly for carrying out the evaluation method, and an evaluation fuel cell.

A fuel cell (cell) has a membrane-electrode assembly (MEA) in which an anode is provided on one surface of the electrolyte membrane and a cathode is provided on multiple surfaces, and a pair of separators in which a reaction gas channel is formed on the MEA facing surface side through a diffusion layer Consists of what is sandwiched between. The larger the contact area between the MEA and the gas flowing through the reaction gas, the larger the generated current. Therefore, it is important that the reaction gas flows without being biased in the separator surface. Understanding the gas flow state in the fuel cell is important in developing a fuel cell including determination of an appropriate flow path pattern.
Japanese Patent Application Laid-Open No. 8-293318 discloses a method for evaluating the flow of a reaction gas in a fuel cell in which white smoke is mixed with a supply gas to visualize the gas flow in order to measure the gas flow in a separator flow path. Disclosure.
JP-A-8-293318

Conventional methods for evaluating the flow of reactant gas in a fuel cell have the following problems.
Since white smoke is supplied from the supply gas manifold together with the reaction gas, the gas flow can be visually observed, but the quantitative, gas behavior and gas flow distribution of the gas in the separator surface are not known, and the reaction It is not known whether or not the gas is flowing in the separator surface without being biased, and whether or not the reaction gas flow path has an appropriate flow path pattern for flowing the gas uniformly in the separator surface.

  An object of the present invention is to provide a method, an evaluation apparatus, and an evaluation fuel cell for evaluating the flow of a reactive gas in a fuel cell, which makes it possible to grasp the quantitative behavior and flow distribution of the gas in the separator surface. There is.

The present invention for solving the above problems and achieving the above object is as follows.
(1) supplying a normal reaction gas to the gas flow path of the fuel cell, introducing a test gas from a test gas inlet provided between the normal reaction gas inlet and the outlet of the gas flow path, A method for evaluating the flow of a reaction gas in a fuel cell, comprising: detecting a test gas with a detection unit provided between an inlet and an outlet of a normal reaction gas in a gas flow path.
(2) The test gas is introduced into the gas flow path of the fuel cell at a pressure equal to the gas pressure of the gas flow path of the fuel cell at the test gas inlet. (1) Evaluation of the flow of the reaction gas in the fuel cell according to (1) Method.
(3) The method for evaluating the flow of the reaction gas in the fuel cell according to (1), wherein the inspection gas includes a different type of gas from the reaction gas.
(4) The method for evaluating the flow of the reaction gas in the fuel cell according to (3), wherein when the reaction gas is hydrogen, the type of gas different from the reaction gas is deuterium.
(5) Means for supplying normal reaction gas to the gas flow path of the fuel cell, inspection gas inlet provided between the normal reaction gas inlet and outlet of the gas flow path, and normal reaction in the gas flow path An apparatus for evaluating the flow of a reaction gas in a fuel cell, comprising: a detector for detecting a test gas provided between a gas inlet and an outlet; and a test gas measuring means connected to the detector.
(6) A gas flow path having a normal reaction gas inlet and outlet, a test gas inlet provided between the normal reaction gas inlet and outlet of the gas flow path, and a normal reaction gas flow rate of the gas flow path A fuel cell for evaluating the flow of a reaction gas in a fuel cell having a detection unit for detecting a test gas provided between an inlet and an outlet.

According to (1) the method for evaluating the flow of the reaction gas in the fuel cell, (5) the apparatus for evaluating the flow of the reaction gas in the fuel cell, and (6) the fuel cell for evaluation according to the above (6) Since the inspection gas inlet and the gas detector are provided between the normal reaction gas inlet and outlet, the gas behavior and flow distribution between any two points (inspection gas inlet and detector) can be obtained. .
According to the method for evaluating the flow of the reaction gas in the fuel cell in (2) above, the test gas is supplied to the gas flow path of the fuel cell at a pressure equal to the gas pressure of the gas flow path of the fuel cell at the test gas inlet. Since it introduce | transduces, disturbing the flow of the regular reaction gas is suppressed.
According to the method for evaluating the flow of the reaction gas in the fuel cell in (3) above, since the inspection gas includes a different type of gas from the reaction gas, the inspection gas and the reaction gas can be distinguished from each other, and the accuracy of detection and measurement is increased. Goes up.
According to the method for evaluating the flow of the reaction gas in the fuel cell in (4) above, since the inspection gas contains deuterium, the deuterium also reacts on the electrode, so that the gas flow path during power generation including water generation Can be accurately reproduced, and the test can be performed in a state close to the actual state.

Hereinafter, an evaluation method, an evaluation apparatus, and an evaluation fuel cell for evaluating the flow of reaction gas in a fuel cell according to the present invention will be described with reference to FIGS.
The evaluation object of the flow of the reaction gas of the present invention is, for example, a solid polymer electrolyte fuel cell (cell) 10. The fuel cell 10 is mounted on, for example, a fuel cell vehicle. However, it may be used other than an automobile.
In addition, the evaluation fuel cell 10T used in the evaluation test (T indicates that for the evaluation test) is an inspection gas inlet and outlet (the inspection gas inlet and outlet are the separators of the actual fuel cell 10). A fuel cell having a separator 18T provided with an intermediate manifold provided), and the structure of the gas flow path and the membrane-electrode assembly is the same as the structure of the gas flow path and the membrane-electrode assembly of the actual fuel cell 10. The same.

As shown in FIGS. 3 to 5, the solid polymer electrolyte fuel cell (cell) 10 includes a laminated body of a membrane-electrode assembly (MEA) and a separator 18, for example, MEA as a pair of separators. It consists of something sandwiched between 18.
The membrane-electrode assembly includes an electrolyte membrane 11 made of an ion exchange membrane, an electrode (anode, fuel electrode) 14 made of a catalyst layer disposed on one surface of the electrolyte membrane, and a catalyst layer disposed on the other surface of the electrolyte membrane. It consists of electrodes (cathode, air electrode) 17. Between the membrane-electrode assembly and the separator 18, gas diffusion layers (hereinafter simply referred to as diffusion layers) 13 and 16 are provided on the anode side and the cathode side, respectively.
A cell module 19 is formed by stacking the membrane-electrode assembly and the separator 18 (when one module is constituted by one cell, the cell 10 and the module 19 are the same), and the cell module 19 is laminated to form a cell laminate. Terminals 20, insulators 21, and end plates 22 are arranged at both ends of the stacked body in the cell stacking direction, and bolts are attached to fastening members (for example, tension plates 24) that extend the end plates 22 at both ends in the cell stacking direction outside the cell stacked body. A fuel cell stack 23 is configured by fixing with a nut 25 and applying a fastening load in the cell stacking direction to the cell stack through a spring provided on the inner side with an adjustment screw provided on one end plate.

A fuel gas flow path 27 for supplying fuel gas (hydrogen) to the anode 14 is formed on the MEA facing surface of the separator 18 in the power generation region, and oxidizing gas (oxygen, usually air) is supplied to the cathode 17. For this purpose, an oxidizing gas passage 28 is formed. In addition, a coolant channel 26 for flowing a coolant (usually cooling water) is also formed on the side surface of the separator 18 opposite to the MEA facing surface. In the separator 18, a fuel gas manifold 30, an oxidizing gas manifold 31, and a refrigerant manifold 29 are formed in the non-power generation region. The fuel gas manifold 30 is in communication with the fuel gas passage 27, the oxidizing gas manifold 31 is in communication with the oxidizing gas passage 28, and the refrigerant manifold 29 is in communication with the refrigerant passage 26.
The separator 18 includes a carbon separator, a metal separator, a combination of a metal separator and a resin frame, and the like.
The fuel gas, the oxidizing gas, and the refrigerant are sealed with each other in the cell. The two separators 18 sandwiching the MEA of each cell module 19 are sealed by a first seal member 32, and the adjacent cell modules 19 are sealed by a second seal member 33.

An ionization reaction that converts hydrogen into hydrogen ions (protons) and electrons is performed on the anode 14 side of each cell 10 (in the case of a one-cell module, the cell 10 is the same as the cell module 19). The electrolyte moves through the electrolyte membrane 11 to the cathode 17 side. On the cathode 17 side, oxygen, hydrogen ions, and electrons (electrons generated at the anode of the adjacent MEA pass through the separator, or electrons generated at the anode of the cell at one end in the cell stacking direction). From an external circuit to the cathode of the other cell), and water is generated according to the following equation.
Anode side: H ₂ → 2H ⁺ + 2e ⁻
Cathode side: 2H ⁺ + 2e ⁻ + (1/2) O ₂ → H ₂ O

  In order for power generation to be performed in the entire power generation region, it is important that the reaction gas (fuel gas, oxidant gas) flows uniformly in the plane of the separator 18. It is important for the development of the fuel cell to grasp the gas behavior and the flow rate distribution using the evaluation fuel cell 10T having the test separator 18T having the gas flow paths 27, 28 having the same structure as the separator 18. is there.

An apparatus 50 for evaluating the flow of reaction gas in the fuel cell and the evaluation fuel cell 10T for performing this test will be described with reference to FIGS.
The evaluation fuel cell 10T of the present invention has an inlet (communication path to the inlet side gas manifold) 51 and an outlet (communication path to the outlet side gas manifold) 52 of the normal reaction gas (fuel gas and / or oxidant gas). The normal reaction gas inlet 51 and the outlet 52 of the gas flow paths 27 and 28 and the gas flow paths 27 and 28 (both the fuel gas flow path 27 and the oxidation gas flow path 28 may be either or both). And a normal reaction gas inlet 51 of the gas flow paths 27 and 28 (both the fuel gas flow path 27 and the oxidant gas flow path 28 may be either or both). And a detection portion 54 for detecting a test gas provided between the gas outlet and the outlet 52. A required amount of gas flowing through the gas flow path in the fuel cell is extracted from the detection unit 54 and analyzed. Other fuel cell configurations conform to the fuel cell configurations of FIGS.

  The reaction gas flow evaluation device 50 in the fuel cell of the present invention may include the gas flow paths 27 and 28 of the evaluation fuel cell 10T (both the fuel gas flow path 27 and the oxidation gas flow path 28, or one of them). May be connected to the inspection gas inlet 53 and the inspection gas inlet 53 provided between the normal reaction gas inlet 51 and the outlet 52 of the gas flow paths 27, 28. The inspection gas supply means 56, the detection gas detection detector 54 provided between the normal reaction gas inlet 51 and the outlet 52 of the gas flow paths 27 and 28, and the detection gas 54 are connected to the detection gas 54. And an inspection gas measuring means 57.

The normal reaction gas supply means 55 includes, for example, normal reaction gas sources 58 and 59 (fuel gas gas source 58 and oxidizing gas gas source 59) and gas from the gas sources 58 and 59 to the reaction gas inlet 51. A pressure adjustment valve 61 and a flow rate adjustment valve 62 provided in the middle of the supply pipe 60 and electromagnetic valves 64 and 65 provided on both sides of the flange 63 that can be separated from the pipe are included. Further, a humidifier 66 may be provided in the oxidizing gas supply pipe to humidify the oxidizing gas. However, the system configuration is not limited to this.
A gas discharge pipe 67 is connected to the reaction gas outlet 52, and an electromagnetic valve 68 is provided in the middle of the gas discharge pipe 67. However, the system configuration is not limited to this.

  The inspection gas supply means 56 is, for example, a gas of a different type from the normal reaction gas (for example, for inspecting an oxidizing gas such as deuterium, nitrogen, helium or carbon dioxide for the inspection of fuel gas). And an electromagnetic valve 73 provided on both sides of a flange 72 capable of separating the inspection gas supply pipe 71 when changing the gas source. 74, a switching valve 75 for switching the supply of the inspection gas between the fuel gas passage 27 and the oxidant gas passage 28, and a pressure adjusting valve 76 (provided in the middle of the inspection gas supply pipe 71). A pressure regulating valve for equalizing the pressure of the inspection gas to the gas pressure flowing through the gas flow passages 27 and 28 to which the inspection gas is supplied. For example, the gas flow passages 27 and 28 to which the inspection gas is supplied. Part And a solenoid valve 79 provided on both sides of a flange 78 capable of separating the inspection gas supply piping system and the evaluation fuel cell 10T from a diaphragm valve whose pressure is guided to a diaphragm chamber from a pipe 77 through a conduit 77, 80, and electromagnetic valves 82 and 83 provided on both sides of a flange 81 capable of separating the conduit 77 and the evaluation fuel cell 10T. However, the system configuration is not limited to this.

  The inspection gas measuring means 57 connected to the detection unit 54 includes a quantitative analyzer 85 (for example, a mass spectrometer) that quantitatively analyzes the gas from which the sample gas extracted from the detection unit 54 is guided through the conduit 84, and A qualitative analyzer 86 (for example, a chromatograph, an emission spectrometer, an absorption spectrometer, etc.) for qualitatively analyzing the gas from which the sample gas taken out from the detection unit 54 is guided through the conduit 84, and a flange capable of separating the conduit 84 87, an electromagnetic valve 88 provided on the fuel cell 10T side, a switching valve 89 that switches a detection target between fuel gas and oxidizing gas, and a computer 90 that is connected to an analyzer and processes data. However, the system configuration is not limited to this. Moreover, it is desirable that the analyzers 85 and 86 can analyze the generated water of the fuel cell.

Next, a method for evaluating the flow of the reaction gas in the fuel cell of the present invention, which is performed using the above-described evaluation apparatus, will be described.
The method for evaluating the flow of the reaction gas in the fuel cell according to the present invention includes a step of supplying a normal reaction gas (fuel gas and / or oxidizing gas) to the gas flow paths 27 and 28 of the evaluation fuel cell 10T, While flowing the reaction gas into the gas flow paths 27, 28, the inspection gas is supplied to the gas flow paths 27, 28 from the inspection gas inlet 53 provided between the normal reaction gas inlet 51 and the outlet 52 of the gas flow paths 27, 28. The inspection gas is detected by the detecting unit 54 provided between the inlet 51 and the outlet 52 of the normal reaction gas in the gas flow paths 27 and 28 in the introducing step (the gas taken out by the detecting unit 54 is quantitatively analyzed) 85 and / or sent to the qualitative analyzer 86 to detect the test gas), and the computer 90 calculates the flow rate distribution and flow velocity of the test gas in the separator plane based on the detected data. .

  One or more detection gas inlets 53 may be provided, and a plurality of detection gas inlets 53 may be provided. One or more detection units 54 may be provided, and a plurality of detection units 54 may be provided. By arbitrarily selecting a set of the detection gas inlet 53 and the detection unit 54, it is desirable that there are two or more arbitrary points (two or more points excluding the inlet 51 and the outlet 52). It is possible to detect the concentration of the inspection gas at a point including two or more points, and calculate and analyze it with a computer or the like, thereby inspecting the gas flow distribution in the separator surface (for example, inspection at a certain gas introduction point) Gas can be detected by detecting the concentration of the test gas at multiple points and gas flow rate), gas flow rate (for example, the gas flow rate can be detected from the time required for the test gas to flow from the gas introduction point to the detector) Can be requested.

  The inspection gas is introduced into the gas passages 27 and 28 of the fuel cell 10T at a pressure equal to the gas pressure of the gas passages 27 and 28 of the fuel cell 10T at the inspection gas inlet 53. When the diaphragm type pressure regulating valve 76 is used, the gas flow 27 of the fuel cell 10T can be easily supplied with the test gas at a pressure equal to the gas pressure of the gas flow channel 27, 28 of the fuel cell 10T at the test gas inlet 53. , 28.

The inspection gas includes a different type of gas from the reactive gas (hydrogen and / or air). The inspection gas may be a gas whose type of gas different from that of the reactive gas (hydrogen and / or air) may be 100%, or may react with a type of gas different from the reactive gas (hydrogen and / or air). It may be a mixed gas with gas.
The kind of gas different from the reactive gas is desirably a gas that does not react with the reactive gas. When the reaction gas is hydrogen, deuterium, helium, nitrogen, carbon dioxide, or the like can be used as the inspection gas. When the reaction gas is air, helium, nitrogen, carbon dioxide gas or the like can be used as the inspection gas.

Next, the operation and effect of the evaluation method of the flow of the reaction gas in the fuel cell, the evaluation device 50, and the evaluation fuel cell 18T of the present invention will be described.
First, since the inspection gas inlet 53 and the detection unit 54 are provided between the normal reaction gas inlet 51 and the outlet 52 of the gas flow paths 27 and 28, two arbitrary points (the inspection gas inlet 53 and the detection unit 54) are provided. It is possible to quantitatively determine the gas behavior and flow rate distribution.

In addition, since the inspection gas is introduced into the gas flow paths 27 and 28 of the fuel cell at a pressure equal to the gas pressure of the gas flow paths 27 and 28 of the fuel cell at the inspection gas inlet 53, the flow of the normal reaction gas is reduced. Disturbance is suppressed.
In addition, since the inspection gas contains a different type of gas from the reaction gas, the inspection gas and the reaction gas can be distinguished from each other, and the accuracy of detection and measurement is improved.
In addition, when the inspection gas contains deuterium, deuterium also reacts on the electrode, so that the state in the gas flow paths 27 and 28 during power generation, including water generation, can be accurately reproduced. However, it is possible to perform an evaluation test of the flow of the gas flow in a state close to actuality.

It is a front view of the fuel cell for evaluation of the flow of the reaction gas in the fuel cell of the present invention. It is a systematic diagram of the evaluation apparatus of the flow of the reaction gas in the fuel cell of the present invention. It is a side view of the stack of the fuel cell to which the evaluation method of the present invention is applied. It is a partially expanded sectional view of FIG. It is a front view of the cell of FIG.

Explanation of symbols

10 (solid polymer electrolyte type) fuel cell 10T evaluation fuel cell 11 electrolyte membrane 13, 16 diffusion layer 14 anode 17 cathode 18 separator 18A evaluation fuel cell separator 19 cell 20 terminal 21 insulator 22 end plate 23 fuel cell stack 24 Fastening member (tension plate)
25 Bolt / Nut 26 Refrigerant flow path (fluid flow path)
27 Fuel gas flow path (fluid flow path)
28 Oxidizing gas channel (fluid channel)
29 Refrigerant manifold (fluid manifold)
30 Fuel gas manifold (fluid manifold)
31 Oxidizing gas manifold (fluid manifold)
32 Gasket 33 Adhesive 50 Evaluation Device 51 for Flow of Reactive Gas in Fuel Cell 51 Regular Reaction Gas Inlet 52 Regular Reaction Gas Outlet 53 Inspection Gas Inlet 54 Detection Unit 55 Means for Supplying Regular Reaction Gas 56 Inspection Gas Gas supply pipe 61 Pressure supply valve 62 Flow rate adjustment valve 63 Flow rate adjustment valve 63 Flange 64, 65 Electromagnetic valve 66 Humidifier 67 Gas discharge pipe 68 Electromagnetic valve 70 Inspection gas source 71 Inspection gas measurement means 58, 59 Gas supply piping 72 Flange 73, 74 Solenoid valve 75 Switching valve 76 Pressure regulating valve 77 Conduit 78 Flange 79, 80 Solenoid valve 81 Flange 82, 83 Solenoid valve 84 Conduit 85 Quantitative analyzer (for example, mass spectrometer)
86 Qualitative analyzers (eg chromatographs, emission spectrometers, absorption spectrometers, etc.)
87 Flange 88 Solenoid valve 89 Switching valve 90 Computer

Claims (6)

  A step of supplying a normal reaction gas to the gas flow path of the fuel cell, a step of introducing a test gas from an inspection gas inlet provided between the normal reaction gas inlet and the outlet of the gas flow path, and a gas flow path. The method of evaluating the flow of the reaction gas in the fuel cell, comprising the step of detecting the inspection gas with a detection unit provided between the inlet and the outlet of the regular reaction gas.   The method for evaluating a flow of a reaction gas in a fuel cell according to claim 1, wherein the inspection gas is introduced into the gas flow path of the fuel cell at a pressure equal to the gas pressure of the gas flow path of the fuel cell at the inspection gas inlet.   The method for evaluating a flow of a reaction gas in a fuel cell according to claim 1, wherein the inspection gas contains a different type of gas from the reaction gas.   4. The method for evaluating the flow of a reaction gas in a fuel cell according to claim 3, wherein when the reaction gas is hydrogen, the type of gas different from the reaction gas is deuterium.   Means for supplying normal reaction gas to the gas flow path of the fuel cell, inspection gas inlet provided between the normal reaction gas inlet and outlet of the gas flow path, and normal reaction gas inlet of the gas flow path An apparatus for evaluating the flow of a reaction gas in a fuel cell, comprising: a detection unit for detecting a test gas provided between a gas outlet and an outlet; and a test gas measuring unit connected to the detection unit.   A gas flow path having a normal reaction gas inlet and outlet, a test gas inlet provided between the normal reaction gas inlet and outlet of the gas flow path, and a normal reaction gas inlet and outlet of the gas flow path A fuel cell for evaluation of the flow of reaction gas in a fuel cell having a detection unit for detecting a test gas provided between the two.

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