JP2011187432A - Local current measuring device of fuel cell and fuel cell diagnosis device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a local current measuring device measuring a local current of a fuel cell with a simple structure and a high accuracy, and a fuel cell diagnosis device diagnosing an operation state of the fuel cell with a simple structure and a high accuracy. <P>SOLUTION: As seen from a laminating direction of a cell 21, a hydrogen side magnetic material core 51 is arranged so that a part thereof is exposed to an outside of the fuel cell 20 and that the remaining part thereof surrounds a region (local area) including a proximity of a fuel gas side outlet inside the cell 21, and an air side magnetic material core 52 is arranged so that the remaining part surrounds a region (local area) including a proximity of an oxidizer gas outlet inside the cell 21. Furthermore, at the part of the hydrogen side magnetic material core 51 and the air side magnetic material core 52 exposed to the outside of the fuel cell 20, the local currents flowing through the regions surrounded by the magnetic material cores 51, 52 are detected by magnetic sensors 54a, 54b detecting magnetic field intensity formed in the magnetic material cores 51, 52, respectively. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a local current measuring device that measures a current flowing locally in a fuel cell in which a plurality of cells that output electrical energy are stacked, and a fuel cell diagnostic device, which is a fuel gas shortage state, an oxidant gas shortage state, or It is suitable for use in detecting the operating state of the fuel cell such as a dry-up state.

  2. Description of the Related Art Conventionally, a fuel cell configured by stacking a plurality of cells that output electric energy using an electrochemical reaction between a fuel gas (hydrogen) and an oxidant gas (oxygen) is known.

  In this type of fuel cell, if some cells are in a fuel gas shortage state, an oxidant gas shortage state, or a dry-up state in which the inside of the cell is dry, the cells cannot output electrical energy. Instead, the cell becomes an electric resistance, and the power generation amount of the entire fuel cell is remarkably reduced.

  On the other hand, Patent Document 1 discloses a fuel cell such as a fuel gas shortage state, an oxidant gas shortage state, or a dry-up state by using a current measurement device that detects a local current flowing locally in the fuel cell with a magnetic sensor. Means for detecting the operating state of the are disclosed.

  Specifically, the local current measuring device of Patent Document 1 forms a groove in a plate-like conductor disposed between stacked cells, and is disposed so as to be surrounded by the groove so as to be located in a local portion of the cell. It has a columnar part that comes into contact with it and a magnetic sensor that measures the strength of the magnetic field generated around the columnar part.

  In Patent Document 2, a plurality of sensors for measuring the magnetic field density for measuring the density of the magnetic field generated by the fuel cell are arranged outside the fuel cell during power generation, and the fuel cell is measured using the measured values of these sensors. A method for determining the current density distribution within is disclosed.

JP-A-2005-123162 JP-T-2004-500689

  As described in Patent Document 1 described above, it is possible to detect the operating state of the fuel cell by measuring the local current of the fuel cell. However, in the local current measuring device of Patent Document 1, it is necessary to provide a columnar part and a magnetic sensor inside a conductor arranged between stacked cells, that is, inside a fuel cell, and an output signal of the magnetic sensor is taken out. Therefore, the electrical wiring is likely to be complicated.

  Further, if the current density distribution in the fuel cell is determined using the method of Patent Document 2 and it is determined which part of the fuel cell has a relatively low current density, the local current can be measured. Similarly to the above, the operating state of the fuel cell can be detected.

  However, in a fuel cell configured by stacking a plurality of cells, even if some cells are in a fuel gas shortage state, an oxidant gas shortage state, or a dry-up state, the magnetic field change outside the fuel cell The difference is very small. For this reason, there exists a possibility of misdetecting the operating state of a fuel cell. For example, a fuel cell mounted on a vehicle is easily affected by a magnetic field generated by the operation of another on-vehicle device, and the method of Patent Document 2 is likely to erroneously detect the operating state of the fuel cell.

  In view of the above points, the present invention has a first object to provide a local current measuring device capable of measuring the local current of a fuel cell with a simple configuration and high accuracy, with a simple configuration, and A second object is to provide a fuel cell diagnostic device capable of diagnosing the operating state of a fuel cell with high accuracy.

In order to achieve the first object, according to the first aspect of the present invention, there is provided a local fuel cell (20) in which a plurality of cells (21) that generate electricity by electrochemical reaction of an oxidant gas and a fuel gas are stacked. A local current measuring device for measuring a current flowing through
When viewed from the stacking direction of the cell (21), at least a portion thereof is superposed with the cell (21), and the magnetic material core (51, 51) made of a magnetic material disposed so as to surround a predetermined region of the cell (21). 52) and magnetic field strength detecting means (54a, 54b) for detecting the strength of the magnetic field formed in the magnetic material core (51, 52), and a part of the magnetic material core (51, 52) is a fuel cell. The magnetic field intensity detecting means (54a, 54b) is exposed to the outside of (20), and the magnetic field intensity detecting means (54a, 54b) generates a magnetic field by a magnetic flux passing through a portion of the magnetic material core (51, 52) exposed to the outside of the fuel cell (20). It is characterized by detecting strength.

  According to this, when a current flows in a predetermined region surrounded by the magnetic material cores (51, 52), a magnetic field corresponding to the current is generated in the magnetic material cores (51, 52). Therefore, it is possible to measure the current flowing in a predetermined region, that is, the local area of the fuel cell (20), from the detection value of the magnetic field strength detection means (54a, 54b) that detects the strength of the generated magnetic field.

  At this time, the magnetic field strength detecting means (54a, 54b) detects the strength of the magnetic field by the magnetic flux passing through the portion of the magnetic material core (51, 52) exposed to the outside of the fuel cell (20). The intensity detecting means (54a, 54b) can be arranged outside the fuel cell (20), and the output can be easily taken out. Therefore, the configuration of the local current measuring device can be simplified as compared with the case where the magnetic field strength detecting means (54a, 54b) is arranged between the stacked cells (21).

  Further, since the magnetic material cores (51, 52) are arranged so as to overlap with the cells (21) when viewed from the stacking direction of the cells (21), the magnetic material cores (51, 52) are arranged. ) Is disposed outside the cell (21), the magnetic field formed in the magnetic material core (51, 52) is stronger. Therefore, the local current of the fuel cell can be measured with high accuracy.

  As a result, a local current measuring device capable of measuring the local current of the fuel cell (20) with a simple configuration and high accuracy can be provided. In addition, “surrounding the predetermined area” in the present claims does not only mean surrounding the entire periphery of the predetermined area but also includes the meaning of enclosing a part of the predetermined area.

  Furthermore, in the local current measuring device for a fuel cell having the above characteristics, the predetermined region includes a region where the current changes when the fuel gas becomes deficient, a region where the current changes when the oxidant gas becomes deficient, etc. By selecting this, the operating state of the fuel cell can be detected with a simple configuration and with high accuracy.

  Specifically, as in the invention described in claim 2, in the local current measuring device for a fuel cell according to claim 1, the predetermined region is a fuel gas side outlet that allows the fuel gas to flow out of the cell (21). A fuel gas side magnetic material core (51) arranged so as to surround a region including the vicinity and including a fuel gas side outlet vicinity is provided as a magnetic material core.

  In the region near the fuel gas side outlet, the local current decreases when the fuel gas becomes deficient. Therefore, it is possible to detect that the fuel cell (20) is in a fuel gas shortage state by setting the predetermined region to a region including the vicinity of the fuel gas side outlet.

  Further, as in the invention described in claim 3, in the local current measuring device for a fuel cell according to claim 1 or 2, the predetermined region is an oxidant gas side outlet through which the oxidant gas flows out from the cell (21). An oxidant gas side magnetic material core (52) arranged so as to surround the region including the vicinity of the oxidant gas side outlet part may be provided as a magnetic material core.

  In the region near the oxidant gas side outlet, the local current decreases when the oxidant gas becomes deficient. Therefore, it is possible to detect that the fuel cell (20) is in an oxidant gas shortage state by setting the predetermined region as a region including the vicinity of the oxidant gas side outlet.

  According to a fourth aspect of the present invention, in the fuel cell local current measuring device according to any one of the first to third aspects, the magnetic material core (51, 52) is The two end portions (51a, 51b, 52a, 52b) on the open end side of the U-shape are exposed to the outside of the fuel cell (20), and further, the two end portions Part (51a ... 52b) is magnetically connected to each other, and the magnetic flux between one tip (51a ... 52b) and the other tip (51a ... 52b) of the two tips (51a ... 52b) Including magnetic flux collecting cores (53a, 53b) made of a magnetic material that passes the magnetic field, and the magnetic field strength detecting means (54a, 54b) detects the strength of the magnetic field by the magnetic flux collecting cores (53a, 53b). To do.

  According to this, the magnetic flux collecting cores (53a, 53b) that magnetically connect the two tip portions (51a... 52b) can be formed in an arbitrary shape, and the output of the magnetic field strength detection means (54a, 54b). Can be taken out more easily.

  According to a fifth aspect of the present invention, in the fuel cell local current measuring device according to the fourth aspect, a plurality of magnetic material cores (51, 52) are provided, and the magnetic flux collecting cores (53a, 53b) are: The magnetic flux passing between one tip (51a ... 52b) and the other tip (51a ... 52b) in the plurality of magnetic material cores (51, 52) is collected and passed.

  According to this, since the magnetic flux collecting cores (53a, 53b) collect and pass the magnetic flux between the two tip portions (51a ... 52b) in the plurality of magnetic material cores (51, 52), one magnetic material The amount of magnetic flux passing through the magnetic flux collecting cores (53a, 53b) can be increased as compared with the case where only the magnetic flux between the two tip portions (51a ... 52b) in the core (51, 52) is passed. Therefore, the local current of the fuel cell (20) can be measured with higher accuracy.

  Specifically, as in the invention described in claim 6, in the local current measuring device for a fuel cell according to claim 5, the magnetic flux collecting cores (53a, 53b) extend in the stacking direction, and a plurality of magnetic materials The first belt-like portions (531a, 531b) that magnetically connect one end portions (51a ... 52b) of the cores (51, 52), extending in the stacking direction, and having a plurality of magnetic material cores (51, 52). The second strips (532a, 532b) that magnetically connect the other tip portions (51a ... 52b), and the first strips (531a, 531b) and the second strips (532a, 532b) are magnetically coupled. The third strips (533a, 533b) are connected in the stacking direction and the width (W) in the stacking direction of the third strips (533a, 533b) is the same as the stacking direction of the first strips (531a, 531b). Length dimension (L1) and second strip ( 32a, wherein the shorter than the stacking direction of the length (L2) of 532b).

  According to this, the width dimension (W) in the stacking direction of the third strips (533a, 533b) is the length in the stacking direction of the first strips (531a, 531b) and the second strips (532a, 532b). Since it is shorter than the dimensions (L1, L2), it is possible to increase the amount of magnetic flux passing through the third strips (533a, 533b).

  Furthermore, as in the seventh aspect of the invention, in the fuel cell local current measuring device according to the sixth aspect, a plurality of the third strip portions (533a, 533b) may be provided. According to this, it is possible to appropriately distribute a plurality of magnetic fluxes passing through the third belt portions (533a, 533b), and to prevent magnetic saturation from occurring in the third belt portions (533a, 533b).

  According to an eighth aspect of the present invention, in the local current measuring device for a fuel cell according to any one of the fourth to seventh aspects, the magnetic material core (51, 52) and the magnetic flux collecting core (53a, 53b) are It is characterized by being electrically insulated. Thereby, it can prevent that the electric current which flows as a whole fuel cell (20) short-circuits in the magnetic collection core (53a, 53b).

  According to a ninth aspect of the invention, in the fuel cell local current measuring device according to any one of the first to third aspects, the magnetic material cores (51, 52) are viewed from the stacking direction of the cells (21). It is characterized in that it is formed in a ring shape.

  According to this, the magnetic material strength detection means (54a, 54b) is directly exposed to the magnetic material core (51, 52) at a portion of the magnetic material core (51, 52) exposed to the outside of the fuel cell (20). It is possible to detect the strength of the magnetic field formed on the surface.

  In order to achieve the second object, in the invention according to claim 10, a fuel cell (20) in which a plurality of cells (21) that generate electricity by electrochemical reaction of an oxidant gas and a fuel gas are stacked. A fuel cell diagnostic apparatus for diagnosing the operating state of the magnetic field strength detecting means (66) for detecting the strength of the magnetic field and at least a part of the cells (21) when viewed from the stacking direction of the cells (21). And a fuel gas side magnetic material core (61) made of a magnetic material disposed so as to surround the first region including the vicinity of the fuel gas side outlet portion from which the fuel gas flows out from the cell (21), When viewed from the stacking direction of the cell (21), at least a part of the second region includes the vicinity of the oxidant gas side outlet for allowing the oxidant gas to flow out of the cell (21) while being superposed with the cell (21). Magnets placed around An oxidant gas side magnetic material core (62) made of a material, and a connecting core made of a magnetic material that allows a magnetic flux between the fuel gas side magnetic material core (61) and the oxidant gas side magnetic material core (62) to pass therethrough ( 63) and diagnostic means (40b) for diagnosing the operating state of the fuel cell (20) based on the detection value of the magnetic field strength detection means (66), and the connecting core (63) is a fuel gas side magnetic material. The direction of the magnetic flux from the core (61) and the direction of the magnetic flux from the oxidant gas side magnetic material core (62) are opposite to each other, and the fuel gas side magnetic material core (61) and the oxidant gas side The magnetic material core (62) is magnetically connected to each of the magnetic material cores (62), and the magnetic field intensity detecting means (66) is arranged in the connecting core (63) and is connected to the connecting core (63) by the magnetic flux passing through the connecting core (63). It is characterized by detecting the strength of the magnetic field. That.

  According to this, in the connecting core (63), the direction of the magnetic flux from the fuel gas side magnetic material core (61) is opposite to the direction of the magnetic flux from the oxidant gas side magnetic material core (62). In the core (63), the magnetic fluxes from the magnetic material cores (61, 62) act so as to cancel each other.

  Here, when some of the cells (21) in the fuel cell (20) are in a fuel gas shortage state or an oxidant gas shortage state, the strength of the magnetic field generated in the fuel gas side magnetic material core (61) and the oxidant gas side The magnetic field strength generated in the magnetic material core (62) is biased. In this case, in the connecting core (63), the magnetic flux from each magnetic material core (61, 62) is not canceled out, and the magnetic flux that is the difference amount of each magnetic material core (61, 62) passes.

  For this reason, the strength of the magnetic field generated in the fuel gas side magnetic material core (61) and the oxidant gas side magnetic material core are detected by detecting the strength of the magnetic field in the connecting core (63) with the magnetic field strength detection means (66). The deviation of the magnetic field strength generated in (62) can be detected, and the operation of the fuel cell (20) such as the fuel gas shortage state or the oxidant gas shortage state based on the detection value of the magnetic field strength detection means (66). It becomes possible to diagnose the condition.

  At this time, the magnetic field strength detecting means (66) detects the strength of the magnetic field in the connecting core (63), thereby the strength of the magnetic field generated in the fuel gas side magnetic material core (61) and the oxidant gas side magnetic material core. Since the intensity deviation of (62) can be detected, it is not necessary to provide a plurality of magnetic field intensity detection means corresponding to each magnetic material core (61, 62). Therefore, the configuration of the fuel cell diagnostic device can be simplified.

  Further, since the magnetic material cores (61, 62) are arranged so as to overlap with the cells (21) when viewed from the stacking direction of the cells (21), each magnetic material core (61, 62), the magnetic field formed in each magnetic material core (61, 62) becomes stronger than the case where the entirety of 62) is disposed outside the cell (21). Therefore, the operating state of the fuel cell can be diagnosed with high accuracy.

  As a result, it is possible to provide a fuel cell diagnostic device that can diagnose the operating state of the fuel cell (20) with a simple configuration and high accuracy.

  In the invention described in claim 11, in the fuel cell diagnostic device according to claim 10, each of the fuel gas side magnetic material core (61) and the oxidant gas side magnetic material core (62) is viewed from the stacking direction. Is partially exposed to the outside of the fuel cell (20), and the connecting core (63) is composed of the fuel gas side magnetic material core (61) and the oxidant gas side magnetic material core (62). It is characterized in that the parts exposed to the outside of the fuel cell (20) are magnetically connected to each other.

  According to this, in the magnetic field strength detection means (66), among the magnetic material cores (61, 62), the magnetic flux passing through the connecting core (63) connecting the portions exposed to the outside of the fuel cell (20). Since the strength of the magnetic field is detected, the magnetic field strength detecting means (66) can be arranged outside the fuel cell (20), and the output can be easily taken out. Therefore, the configuration of the fuel cell diagnostic device can be simplified as compared with the case where the magnetic field strength detecting means (66) is arranged between the stacked cells (21).

  Further, in the invention according to claim 12, in the fuel cell diagnostic device according to claim 11, each of the fuel gas side magnetic material core (61) and the oxidant gas side magnetic material core (62) includes a plurality of cells. (21), extending in the stacking direction, magnetically connecting each of the plurality of fuel gas side magnetic material cores (61), and passing through the plurality of fuel gas side magnetic material cores (61) A plurality of oxidant gas side magnetic cores (64) that pass through the gas gas collecting core (64) and a plurality of oxidant gas side magnetic material cores (62) that extend in the stacking direction and are magnetically connected to each other. An oxidant gas side magnetic flux collecting core (65) that collects and passes magnetic fluxes passing through the magnetic material core (62), and the connecting core (63) includes the fuel gas side magnetic flux collecting core (64) and the oxidant. Fuel gas side through gas side magnetic collecting core (65) Of sex material core (61) and the oxidizing gas side magnetic material core (62), characterized in that the parts together exposed to the outside of the fuel cell (20) is constituted by magnetically coupled.

  According to this, the fuel gas side magnetic collecting core (64) collects and passes the magnetic flux between the plurality of fuel gas side magnetic material cores (61), and the oxidant gas side magnetic collecting core (65) has a plurality of oxidations. Since the magnetic flux between the agent gas side magnetic material cores (62) is collected and passed, the amount of magnetic flux passing through the connecting core (63) can be increased. Therefore, the operating state of the fuel cell (20) can be diagnosed with higher accuracy.

  According to a thirteenth aspect of the present invention, in the fuel cell diagnostic apparatus of the twelfth aspect, the fuel gas side magnetic material core (61) and the fuel gas side magnetic flux collecting core (64) are electrically insulated. The oxidant gas side magnetic material core (62) and the oxidant gas side magnetic core (65) are electrically insulated. Thereby, it can prevent that the electric current which flows as a whole fuel cell (20) is short-circuited by each magnetism collection core (64, 65).

  Further, as in the invention described in claim 14, in the fuel cell diagnostic device according to any one of claims 10 to 13, the diagnosis means (40b) uses the detection value of the magnetic field strength detection means (66). Based on this, the magnitude of the magnetic field strength in the fuel gas side magnetic material core (61) and the oxidant gas side magnetic material core (62) is determined, and the strength of the magnetic field in the fuel gas side magnetic material core (61) is oxidized. When it is determined that the strength of the magnetic field in the oxidant gas side magnetic material core (62) is smaller than the predetermined first reference value, it is diagnosed that the fuel gas is insufficient, and the oxidant gas side magnetic material core A state in which the oxidant gas is insufficient when it is determined that the magnetic field strength in (62) is smaller than the magnetic field strength in the fuel gas side magnetic material core (61) by a predetermined second reference value; You may make it diagnose.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

1 is an overall configuration diagram of a fuel cell to which a local current measuring device according to a first embodiment is applied. It is the perspective view which expanded the principal part of the local current measuring device of a 1st embodiment. It is sectional drawing of the lamination direction of the cell 21 of 1st Embodiment. It is the A section enlarged view of FIG. It is a flowchart which shows the control processing in the control apparatus of 1st Embodiment. It is the perspective view which expanded the principal part of the local current measuring device of a 2nd embodiment. It is the perspective view which expanded the principal part of the local current measuring device of 3rd Embodiment. It is a whole block diagram of the fuel cell to which the fuel cell diagnostic apparatus of 4th Embodiment is applied. It is the perspective view which expanded the principal part of the fuel cell diagnostic apparatus of 4th Embodiment. It is the B section enlarged view of FIG. It is the front view which looked at the fuel cell diagnostic apparatus of 4th Embodiment from the lamination direction. It is a flowchart which shows the control processing in the control apparatus of 4th Embodiment. It is the front view which looked at the fuel cell diagnostic apparatus of 5th Embodiment from the lamination direction. It is the perspective view which expanded the principal part of the fuel cell diagnostic apparatus of 6th Embodiment.

(First embodiment)
1 to 5, an embodiment of the local current measuring apparatus 10 according to the present invention will be described. FIG. 1 is a schematic overall configuration diagram of a fuel cell 20 to which a local current measuring device 10 of the present embodiment is applied. Further, FIG. 1 also shows an electrical connection relationship between the local current measuring device 10 and the fuel cell 20. First, the fuel cell 20 is mounted on a fuel cell vehicle, which is a kind of electric vehicle, and supplies power to an electric load 30 such as an electric motor for driving the vehicle, a secondary battery, and various auxiliary machines for the vehicle.

  This fuel cell 20 outputs electric energy by utilizing an electrochemical reaction between a fuel gas (hydrogen) and an oxidant gas (oxygen in the air), and is a flat fuel cell 21 (a basic unit). Hereinafter, the cell 21 is simply described as a cell 21). The plurality of cells 21 are electrically connected in series. In the present embodiment, a solid polymer electrolyte fuel cell is employed as the fuel cell 20.

  In addition, a pair of current collectors for taking out the electric energy output from the fuel cell 20 is provided at both ends of the plurality of cells 21 connected in series, that is, at both ends in the stacking direction of the cells 21 as a whole of the fuel cell 20. A plate 21a is arranged. Various electrical loads 30 are connected to the current collecting plate 21a.

  Furthermore, a voltage sensor 31 that detects a voltage output as the whole fuel cell 20 and a current sensor 32 that detects a current output as the whole fuel cell 20 are connected to the current collector plate 21a. Detection signals from the voltage sensor 31 and the current sensor 32 are input to the control device 40 described later. These voltage sensor 31 and current sensor 32 constitute the local current measuring device 10 of the present embodiment.

  One of the pair of current collector plates 21 a is provided with a hydrogen inlet, a hydrogen outlet, an air inlet, an air outlet, and an inlet and an outlet (not shown) for cooling water that cools the fuel cell 20. ing. The cooling water flows inside the fuel cell 20, and the temperature of the fuel cell 20 during power generation is set to a predetermined temperature (in this embodiment, about 80 ° C.) so that the power generation efficiency of the fuel cell 20 becomes a certain level or more. ).

  Between each cell 21, magnetic material cores 51 and 52 made of a magnetic material (permalloy in this embodiment) are arranged. Each of these magnetic material cores 51 and 52 constitutes the local current measuring device 10 of the present embodiment.

  Next, the detailed configuration of the cell 21 and the arrangement of the magnetic material cores 51 and 52 with respect to the cell 21 will be described with reference to FIGS. 2 is an enlarged perspective view of the main parts of the fuel cell 20 and the local current measuring device 10, FIG. 3 is a cross-sectional view in the stacking direction of the cells 21 of the fuel cell 20, and FIG. It is the enlarged view which looked at the A section of this from the lamination direction of the cell 21. FIG.

  First, the detailed configuration of the cell 21 will be described. As shown in FIG. 3, the cell 21 has a membrane electrode assembly (MEA) 22 and a pair of separators 23 that sandwich the membrane electrode assembly 22 from both sides.

  The membrane electrode assembly 22 is in close contact with the electrolyte membrane 221 made of a solid polymer membrane, the anode-side catalyst layer 222a disposed in close contact with the hydrogen electrode side surface of the electrolyte membrane 221, and the air electrode side surface of the electrolyte membrane 221. Formed on the cathode side catalyst layer 222b, the anode side diffusion layer 223a arranged outside the anode side catalyst layer 222a, and the cathode side diffusion layer 223b arranged outside the cathode side catalyst layer 222b. Yes.

  More specifically, each of the catalyst layers 222a and 222b is formed of a carbon-supported platinum catalyst or the like in which a catalyst (such as platinum) that promotes an electrochemical reaction is supported on a carbon support, and each diffusion layer (GDL: Gas Diffusion Layer). 223a and 223b are formed of a carbon cloth or the like that is a conductor and has liquid moisture retention performance.

  The separator 23 separates the cells 21 from each other while being in electrical contact with the membrane electrode assembly 22 and separates the air flow, the hydrogen flow, and the cooling water flow in each cell 21. The separator 23 is excellent in conductivity and is formed of a nonmagnetic metal (for example, copper or titanium) in a substantially rectangular shape when viewed from the stacking direction of the cells 21.

  In this embodiment, as the separator 23, a hydrogen electrode side separator 23a disposed outside the anode side diffusion layer 223a and an air electrode side separator 23b disposed outside the cathode side diffusion layer 223b are provided.

  A hydrogen channel 231 through which hydrogen flows is formed between the outer side surface of the anode side diffusion layer 223a and the inner side surface of the hydrogen electrode side separator 23a, and the outer surface of the cathode side diffusion layer 223b and the air electrode side separator 23b An air channel 232 through which air flows is formed between the inner surface and the inner surface. Further, as shown in FIG. 3, the hydrogen flow direction in the hydrogen flow path 231 and the air flow direction in the air flow path 232 face each other.

  Further, a groove is formed on the outer surface of the hydrogen electrode side separator 23a. By this groove portion, when the cells 21 are stacked, a cooling water flow path 233 through which cooling water flows is formed between the hydrogen electrode side separator 23a and the air electrode side separator 23b of the adjacent cells 21.

  Of course, the groove portion may be formed on the outer surface of the air electrode side separator 23b to form the cooling water flow path 233, or the groove portion may be formed on the outer surfaces of both the hydrogen electrode side separator 23a and the air electrode side separator 23b. The cooling water channel 233 may be formed.

  In addition, as shown in FIG. 2, the separator 23 of each cell 21 is immersed in the hydrogen inlet hole 211 a for allowing hydrogen to flow into the hydrogen channel 231, unreacted surplus hydrogen that has not been consumed during power generation, and the hydrogen channel 231. A hydrogen outlet hole 211b through which the produced water that has flowed out flows out of the hydrogen channel 231 is formed. The hydrogen inlet hole 211 a and the hydrogen outlet hole 211 b are provided so as to penetrate the front and back of each cell 21.

  Accordingly, when the cells 21 are stacked, the hydrogen inlet holes 211a form hydrogen distribution manifolds that serve as distribution spaces for distributing hydrogen to the hydrogen flow paths 231 in the cells 21, and the hydrogen outlet holes 211b An assembly manifold for hydrogen serving as an assembly space in which surplus hydrogen and product water flowing out from the assembly 21 are collected is formed.

  Further, the separator 23 of each cell 21 has an air inlet hole 212 a through which air flows into the air flow path 232, and surplus air and generated water containing oxygen and nitrogen that have not been consumed during power generation are flowed out from the air flow path 232. An air outlet hole 212b, a cooling water inflow hole 213a for allowing cooling water to flow into the cooling water flow path 233, and a cooling water outflow hole 213b for allowing cooling water to flow out from the cooling water flow path 233 are formed.

  These air inlet hole 212a, air outlet hole 212b, cooling water inflow hole 213a, and cooling water outflow hole 213b are also provided so as to penetrate the front and back of each cell 21. Therefore, when the cells 21 are stacked, similarly to the hydrogen inlet hole 211a and the hydrogen outlet hole 211b, respectively, a distribution manifold for air, a collective manifold for air, a distribution manifold for cooling water, and a collective manifold for cooling water, respectively. Form.

  Next, the arrangement | positioning aspect etc. with respect to the cell 21 of the magnetic material cores 51 and 52 are demonstrated. In the present embodiment, two types of magnetic material cores 51 and 52 are provided: a fuel gas side magnetic material core (hydrogen side magnetic material core) 51 and an oxidant gas side magnetic material core (air side magnetic material core) 52. Yes. Both magnetic material cores 51 and 52 are each formed of a substantially U-shaped plate-like member when viewed from the stacking direction of the cells 21.

  As described above, both the magnetic material cores 51 and 52 are disposed between the cells 21. More specifically, as shown in FIG. 2, when viewed from the stacking direction of the cells 21, both magnetic material cores 51, 52 have two tip portions 51 a, 51 b on the U-shaped open end side. , 52a, 52b are disposed in the cooling water flow path 233 between the cells 21 so that the remaining portions are superposed on the cells 21 in a state where they are exposed to the outside of the fuel cell 20.

  Furthermore, when viewed from the stacking direction of the cells 21, the portions of both the magnetic material cores 51 and 52 that overlap with the cells 21 are arranged so as to surround a predetermined region of the cells 21 with three U-shaped sides. ing. In other words, both the magnetic material cores 51 and 52 are arranged so as to surround a part of the predetermined region from three directions.

  Of the two magnetic material cores 51 and 52, the hydrogen-side magnetic material core 51 includes a region (region close to the hydrogen outlet hole 211b) including the vicinity of the fuel gas-side outlet that allows hydrogen to flow out of the cell 21 as a predetermined region. The air-side magnetic material core 52 surrounds a region (region close to the air outlet hole 212b) including the vicinity of the oxidant gas-side outlet that allows air to flow out of the cell 21 as a predetermined region.

  As described above, in the present embodiment, when the hydrogen flow direction in the hydrogen flow path 231 and the air flow direction in the air flow path 232 are opposed to each other, when viewed from the stacking direction of the cells 21, the fuel It arrange | positions so that the area | region including the gas side exit part vicinity and the area | region containing the oxidizing agent gas side exit part vicinity may not mutually superpose | polymerize.

  Further, the two U-shaped open end sides of the hydrogen-side magnetic material core 51 exposed to the outside of the fuel cell 20 have one end 51a and the other end 51b. Are magnetically connected by a hydrogen-side magnetic flux collecting core 53a that allows magnetic flux between them to pass. The hydrogen-side magnetic flux collecting core 53 a is formed of the same magnetic material as the magnetic material cores 51 and 52.

  Specifically, the hydrogen-side magnetic flux collecting core 53a extends in the stacking direction of the cells 21, and the first band-like portion 531a and the cell that magnetically connect one end portions 51a of the plurality of hydrogen-side magnetic material cores 51 to each other. 21, a second belt-like portion 532 a that magnetically connects the other tip portions 51 b of the plurality of hydrogen-side magnetic material cores 51, and a first belt-like portion 531 a and a second belt-like portion 532 a. It has the 3rd strip | belt-shaped part 533a to connect magnetically.

  The width dimension W in the stacking direction of the cells 21 in the third band-shaped part 533a is the length dimension L1 in the stacking direction of the cells 21 in the first band-shaped part 531a and the length dimension in the stacking direction of the cells 21 in the second band-shaped part 532a. It is shorter than L2. In the present embodiment, specifically, the width dimension W of the third strip portion 533a is equal to or less than the width dimension of one cell 21 in the stacking direction.

  That is, the hydrogen-side magnetic core 53a is formed of a substantially H-shaped plate member when viewed from the direction perpendicular to the stacking direction of the cells 21. Therefore, in the hydrogen side magnetic flux collecting core 53a, the magnetic flux between one tip portion 51a and the other tip portion 51b of the plurality of hydrogen side magnetic material cores 51 can be gathered and passed through the third strip portion 533a. it can.

  Therefore, in the present embodiment, the hydrogen-side magnetic sensor 54a as the magnetic field strength detecting means is arranged on the third belt-like portion 533a of the hydrogen-side magnetic flux collecting core 53a arranged outside the fuel cell 20. The hydrogen side magnetic sensor 54 a detects the strength of the magnetic field formed in the hydrogen side magnetic material core 51 during the power generation of the fuel cell 20.

  In the present embodiment, specifically, a Hall element is employed as the hydrogen-side magnetic sensor 54a, and the hydrogen flux is generated by the magnetic flux passing between one tip portion 51a and the other tip portion 51b of the hydrogen-side magnetic material core 51. The strength of the magnetic field formed in the side magnetic material core 51 is detected. The detection signal of the hydrogen side magnetic sensor 54 a is input to the control device 40.

  Further, as shown in FIG. 4, a resin film 55a is interposed between the plurality of hydrogen-side magnetic material cores 51 and the hydrogen-side magnetic flux collecting core 53a, and the hydrogen-side magnetic material core 51 and the hydrogen-side magnetic flux collecting core. The core 53a is electrically insulated.

  On the other hand, the two U-shaped open ends on the air side magnetic material core 52 that are exposed to the outside of the fuel cell 20 are also configured in exactly the same manner as the hydrogen side magnetic material core 51. Are magnetically connected by the air-side magnetic flux collecting core 53b. Therefore, the air-side magnetic core 53b also has a first belt-like portion 531b, a second belt-like portion 532b, and a third belt-like portion 533b, and is formed in a substantially H-shape like the hydrogen-side magnetic flux collecting core 53a. Yes.

  Further, an air-side magnetic sensor 54b as a magnetic field strength detecting means is also disposed in the third belt-like portion 533b of the air-side magnetic flux collecting core 53b. The air-side magnetic sensor 54b has the same configuration as the hydrogen-side magnetic sensor 54a, and detects the strength of the magnetic field formed in the air-side magnetic material core 52 during power generation of the fuel cell 20.

  Further, as shown in FIG. 4, a resin film 55b is also interposed between the plurality of air-side magnetic material cores 52 and the air-side magnetic flux collecting core 53b. The core 53b is electrically insulated.

  Next, the electric control unit of this embodiment will be described. The control device 40 is composed of a well-known microcomputer including a CPU, a ROM, a RAM and the like and its peripheral circuits, performs various calculations and processing based on an air conditioning control program stored in the ROM, and is connected to the output side. The operation of various control devices is controlled, and the local current of the fuel cell 20 is measured to detect the operating state of the fuel cell 20.

  Various control devices connected to the output side include a display panel 41 for displaying the operating state of the fuel cell 20, hydrogen flow rate adjusting means for adjusting the hydrogen flow rate supplied to the fuel cell 20, and air supplied to the fuel cell 20. There are an air flow rate adjusting means for adjusting the flow rate, and various actuators (none of which are shown) constituting a humidifying amount adjusting means for adjusting the humidifying amount of the air supplied to the fuel cell 20.

  Of course, as the hydrogen flow rate adjusting means, the air flow rate adjusting means, and the humidification amount adjusting means, it is not necessary to adopt any one that is electrically controlled, and an adjusting means constituted by a pure mechanical mechanism may be adopted. . Furthermore, it is not necessary to connect the adjusting means configured by the pure mechanical mechanism to the output side of the control device 40.

  In the control device 40, the control means for controlling the various control devices connected to the output side and the control means for measuring the local current of the fuel cell 20 are integrally configured. In the embodiment, in particular, hardware and software constituting the control means for local current measurement are set as the measurement control means 40a. Of course, the measurement control means 40a may be configured separately from the control device 40.

  Therefore, the local current measuring device 10 of the present embodiment includes the voltage sensor 31, the current sensor 32, the hydrogen side magnetic material core 51, the air side magnetic material core 52, the hydrogen side magnetic flux collecting core 53a, the air side magnetic flux collecting core 53b, and hydrogen. The side magnetic sensor 54a, the air side magnetic sensor 54b, the measurement control means 40a, and the like are configured.

  Next, the operation of the fuel cell 20 and the local current measuring device 10 of the present embodiment having the above configuration will be described.

  When the control device 40 controls the operation of the hydrogen flow rate adjustment actuator, the air flow rate adjustment actuator, and the humidification amount adjustment actuator to supply hydrogen and air to the fuel cell 20, each cell 21 shows the following. In this manner, hydrogen and oxygen are electrochemically reacted to output electric energy.

(Negative electrode side) H ₂ → 2H ⁺ + 2e ⁻
(Positive electrode side) 2H ⁺ + 1 / 2O ₂ + 2e ⁻ → H ₂ O
Then, the electric energy output from the fuel cell 20 is supplied from the current collector plate 21 a to various electric loads 30.

  At this time, the control device 40 controls the operation of various actuators constituting the hydrogen flow rate adjusting means, the air flow rate adjusting means, and the humidification amount adjusting means so that electric power required for the various electric loads 30 can be output.

  Furthermore, the control device 40 measures the local current of the fuel cell 20 based on the detection signals output from the voltage sensor 31, the current sensor 32, the hydrogen-side magnetic sensor 54a, and the air-side magnetic sensor 54b, and at the same time, the fuel cell 20 The operation state such as the fuel gas shortage state, the oxidant gas shortage state or the dry-up state is detected. Then, the operating state is displayed on the display panel 41 according to the detected operating state of the fuel cell 20.

  Here, the current flowing through the fuel cell 20 during power generation (during operation) flows along the stacking direction of the cells 21 as a whole. On the other hand, when viewed from the stacking direction of the cells 21, the magnitudes of the currents flowing through the respective portions of the cells 21 are different. That is, when viewed from the stacking direction of the cells 21, a current density distribution is generated in the current flowing through the cells 21. For this reason, a magnetic field is formed outside and inside the fuel cell 20 by this current.

  More specifically, the current flowing along the stacking direction of the cells 21 as a whole forms a magnetic field outside the fuel cell 20, and the current flowing through a predetermined region (local) of the cell 21 is inside the fuel cell 20. A magnetic field corresponding to the current flowing through the predetermined area is formed around the predetermined area. Therefore, the local current flowing through the predetermined region (local) can be measured by detecting the strength of the magnetic field formed around the predetermined region.

  As described above, in the present embodiment, the hydrogen-side magnetic material core 51 surrounds a region including the vicinity of the fuel gas-side outlet as a predetermined region (region close to the hydrogen outlet hole 211b). Therefore, the magnetic flux passes through the hydrogen side magnetic material core 51 by the magnetic field formed according to the current flowing through the region including the vicinity of the fuel gas side outlet portion.

  The magnetic flux passing through the plurality of hydrogen-side magnetic material cores 51 is collected in the third belt-like portion 533a of the hydrogen-side magnetic core 53a and detected by the hydrogen-side magnetic sensor 54a. Thereby, the strength of the magnetic field formed in the plurality of hydrogen-side magnetic cores 53a can be detected. Furthermore, the control device 40 can measure the local current flowing through the region including the vicinity of the fuel gas side outlet by calculating the detection value of the hydrogen side magnetic sensor 54a.

  In the present embodiment, the air-side magnetic material core 52 surrounds a region including the vicinity of the oxidant gas-side outlet as a predetermined region (region close to the air outlet hole 212b). Accordingly, the magnetic flux passes through the air-side magnetic material core 52 by the magnetic field formed in response to the current flowing through the region including the vicinity of the oxidant gas-side outlet.

  The magnetic flux passing through the plurality of air-side magnetic material cores 52 is collected on the third belt-like portion 533b of the air-side magnetic flux collecting core 53b and detected by the air-side magnetic sensor 54b. Thereby, the intensity of the magnetic field formed in the plurality of air-side magnetic flux collecting cores 53b can be detected. Furthermore, the control device 40 can measure the local current flowing in the region including the vicinity of the oxidant gas side outlet portion by calculating the detection value of the air side magnetic sensor 54b.

  Therefore, in the present embodiment, as shown in the flowchart of FIG. 5, the operating state of the fuel cell 20 is detected using each measured local current. The flowchart of FIG. 5 is executed at predetermined control cycles as a subroutine of a main routine executed by the control device 40 to cause the fuel cell 20 to generate electric power and output electric energy.

  First, in step S1, detection signals of the voltage sensor 31, the current sensor 32, the hydrogen side magnetic sensor 54a, and the air side magnetic sensor 54b are read. In subsequent step S2, it is determined whether or not the internal resistance R of the fuel cell 20 as a whole is equal to or greater than a predetermined reference internal resistance KR. The internal resistance R of the fuel cell 20 as a whole is calculated based on the detection signal from the voltage sensor 31 and the detection signal from the current sensor 32.

  Here, in the fuel cell 20, when the inside of the cell 21 is in a dry-up state, the resistance of the electrolyte membrane 221 of the membrane electrode assembly 22 increases, and thus the internal resistance R of the entire fuel cell 20 increases. Therefore, whether or not the fuel cell 20 is in the dry-up state can be determined based on the magnitude of the internal resistance R of the fuel cell 20.

  Therefore, in this embodiment, when R ≧ KR in step S2, it is assumed that the state is in the dry-up state, and the process proceeds to step S3. In step S3, it is displayed on the display panel 41 that it is a dry-up state, and it progresses to step S4. On the other hand, when R ≧ KR is not satisfied, it is determined that the dry-up state is not established, and the process proceeds to step S4.

  In step S4, it is determined whether or not the hydrogen side local current AH in the region including the vicinity of the fuel gas side outlet portion surrounded by the hydrogen side magnetic material core 51 is lower than the reference hydrogen side local current KAH. The hydrogen side local current AH is calculated based on the detection signal of the hydrogen side magnetic sensor 54a.

  Here, if the flow rate of hydrogen supplied to the fuel cell 20 becomes insufficient, the hydrogen flowing into the hydrogen flow channel 231 is consumed from the inlet side to the outlet side of the hydrogen flow channel 231, and the fuel gas side The hydrogen-side local current AH in the region including the vicinity of the exit portion is reduced. Therefore, whether or not the fuel cell 20 is in a fuel gas shortage state can be determined based on the magnitude of the hydrogen-side local current AH.

  Therefore, in this embodiment, when AH <KAH is satisfied in step S4, it is assumed that the fuel gas is in a shortage state, and the process proceeds to step S5. In step S5, it is displayed on the display panel 41 that the fuel gas is insufficient, and the process proceeds to step S6. On the other hand, when AH <KAH is not satisfied, it is determined that the fuel gas is not insufficient, and the process proceeds to step S6.

  In step S6, it is determined whether or not the air-side local current AAir in the region including the vicinity of the oxidant gas-side outlet surrounded by the air-side magnetic material core 52 is lower than the reference hydrogen-side local current KAAir. The air-side local current AAir is calculated based on the detection signal of the air-side magnetic sensor 54b.

  Here, if excessive generated water is generated in the air flow path 232, the generated water cannot be discharged from the air outlet hole 212 b by the air flow flowing through the air flow path 232. At this time, the generated water that could not be discharged stays in the region including the outlet side of the air flow path 232, that is, the vicinity of the oxidizing gas side outlet portion.

  For this reason, oxygen in the air cannot be supplied to the region including the vicinity of the oxidant gas side outlet, and the air-side local current AAir in the region including the vicinity of the oxidant gas side outlet is reduced. Therefore, it can be determined whether or not the fuel cell 20 is in an oxidant gas shortage state based on the magnitude of the air-side local current AAir.

  Furthermore, when it is determined that the air flow rate adjusting means is in a state where the oxidant gas is deficient even though a sufficient flow rate of air is supplied into the air flow channel 232, It can also be determined that the generated water is in the flooding state where the oxidant gas is deficient due to stagnation.

  Therefore, in this embodiment, when AAair <KAAir is satisfied in step S6, it is determined that the oxidant gas is in a shortage state, and the process proceeds to step S7. In step S7, it is displayed on the display panel 41 that the oxidizing gas is insufficient, and the process returns to the main routine. On the other hand, when AAir <KAAir is not satisfied, it is determined that the oxidant gas is not insufficient, and the process returns to the main routine.

  Since the local current measuring device 10 of the present embodiment operates as described above, the hydrogen side of the region including the vicinity of the fuel gas side outlet portion surrounded by the hydrogen side magnetic material core 51 is detected from the detection value of the hydrogen side magnetic sensor 54a. The local current AH can be measured. Similarly, the air-side local current AAir in the region including the vicinity of the oxidant gas-side outlet surrounded by the air-side magnetic material core 52 can be measured from the detection value of the air-side magnetic sensor 54b.

  At this time, the hydrogen-side magnetic sensor 54a and the air-side magnetic sensor 54b cause the magnetic field strength to be increased by the magnetic flux passing through the portions of the hydrogen-side magnetic material core 51 and the air-side magnetic material core 52 exposed to the outside of the fuel cell 20, respectively. Therefore, the hydrogen-side magnetic sensor 54a and the air-side magnetic sensor 54b can be arranged outside the fuel cell 20, and the output (detection signal) can be easily taken out without complicating the wiring or the like.

  Moreover, the hydrogen side magnetic sensor 54a and the air side magnetic sensor 54b detect the strength of the magnetic field by the hydrogen side magnetic core 53a and the air side magnetic core 53b arranged outside the fuel cell 20. Therefore, the outputs (detection signals) of the hydrogen-side magnetic sensor 54a and the air-side magnetic sensor 54b can be more easily taken out by making the hydrogen-side magnetism collecting core 53a and the air-side magnetism collecting core 53b into arbitrary shapes. it can.

  Further, in the present embodiment, since the hydrogen side magnetic material core 51 and the air side magnetic material core 52 are arranged so as to overlap with the cell 21 when viewed from the stacking direction of the cells 21, In contrast to the case where the entire side magnetic material core 51 and the air side magnetic material core 52 are disposed outside the cell 21, the magnetic fields formed in the hydrogen side magnetic material core 51 and the air side magnetic material core 52 are strengthened. be able to.

  Therefore, the hydrogen-side magnetic sensor 54a can accurately detect the strength of the magnetic field generated around the area including the vicinity of the fuel gas-side outlet, and the air-side magnetic sensor 54b is an area including the vicinity of the oxidant gas-side outlet. The strength of the magnetic field generated around the can be detected with high accuracy. As a result, the hydrogen side local current AH can be accurately measured from the detection value of the hydrogen side magnetic sensor 54a, and the air side local current AAir can be accurately measured from the detection value of the air side magnetic sensor 54b.

  Moreover, in the hydrogen side magnetic flux collecting core 53a and the air side magnetic flux collecting core 53b, the magnetic fluxes passing through the plurality of hydrogen side magnetic material cores 51 and air side magnetic material cores 52 are collected and passed. Specifically, the lengths L1 and L2 in the stacking direction of the first belt-like portions 531a and 531b and the second belt-like portions 532a and 532b of the respective magnetic flux collecting cores 53a and 53b are larger than those of the third belt-like portions 533a and 533b. By reducing the width W, the magnetic flux is gathered and passed.

  Accordingly, the amount of magnetic flux passing through the hydrogen side magnetic core 53a and the air side magnetic core 53b can be increased, and the hydrogen side magnetic sensor 54a and the air side magnetic sensor 54b can increase the magnetic field strength with higher accuracy. Can be detected. As a result, according to the local current measuring device of the fuel cell 20 of the present embodiment, the local current of the fuel cell 20 can be measured with a simple configuration and high accuracy.

  Furthermore, from these local currents, the operating state of the fuel cell 20 such as a shortage of fuel gas, a shortage of oxidant gas, or a dry-up state can be detected with high accuracy. The fact that the operation state of the fuel cell 20 can be detected with high accuracy using the magnetic sensors 54a and 54b as described above is caused by the operation of other in-vehicle devices such as the fuel cell 20 mounted on the vehicle. This is extremely effective when the fuel cell 20 is applied to an environment where a strong magnetic field can be generated.

(Second Embodiment)
In the present embodiment, as shown in FIG. 6, an example in which the number of stacked cells 21 is increased and the shapes of the hydrogen-side magnetic flux collecting core 53a and the air-side magnetic flux collecting core 53b are changed as compared to the first embodiment. To do. FIG. 6 is an enlarged perspective view of the main parts of the fuel cell 20 and the local current measuring device 10 in the present embodiment, and corresponds to FIG. 2 of the first embodiment. Moreover, in FIG. 6, the same code | symbol is attached | subjected to the same or equivalent part as 1st Embodiment.

  Specifically, in this embodiment, the number of stacked cells 21 is about three times that of the first embodiment. Further, a plurality (specifically, three) of third belt-like portions 533a and 533b of the hydrogen-side magnetic flux collecting core 53a and the air-side magnetic flux collecting core 53b are provided. That is, the hydrogen-side magnetic flux collecting core 53a and the air-side magnetic flux collecting core 53b are formed of ladder-like plate members when viewed from the direction perpendicular to the stacking direction of the cells 21.

  In addition, the value which totaled the width dimension W of the lamination direction of these some 3rd strip | belt-shaped parts 533a and 533b is more than the 1st, 2nd strip | belt-shaped parts 531a, 532a, 531b, and 532b similarly to 1st Embodiment. short.

  In addition, one hydrogen-side magnetic sensor 54a and one air-side magnetic sensor 54b similar to those in the first embodiment are disposed in each of the third strip portions 533a and 533b. Therefore, a total of three hydrogen-side magnetic sensors 54a and air-side magnetic sensors 54b according to this embodiment are arranged. Other configurations and operations are the same as those in the first embodiment.

  In the present embodiment, since the third belt-like portions 533a and 533b are provided at a plurality of (specifically, three) locations, the magnetic flux passing through the third belt-like portions 533a and 533b is distributed to the plurality of third belt portions 533a and 533b. It is possible to avoid the occurrence of magnetic saturation in the strip portions 533a and 533b.

  Accordingly, the magnetic field (hydrogen-side local current) formed around the predetermined region (the region including the vicinity of the fuel gas side outlet and the region including the vicinity of the oxidant gas side outlet) of the hydrogen side magnetic sensor 54a and the air side magnetic sensor 54b. Changes in AH and air-side local current AAir) can be accurately measured. As a result, the local current of the fuel cell 20 can be measured with a simple configuration and high accuracy as in the first embodiment.

  Incidentally, in FIG. 2 of the first embodiment, a fuel cell 20 in which six cells 21 are stacked is illustrated, and in FIG. 6, a fuel cell 20 in which eighteen cells 21 are stacked is illustrated. The number of stacked cells 21 is not limited to this. In particular, in the fuel cell 20 applied to a vehicle, it is necessary to stack about 400 cells 21 and output high-voltage power as the entire fuel cell 20.

  According to the study by the present inventors, the third belt-like portions 533a and 533b and the hydrogen-side magnetic sensor 54a and the air-side magnetic sensor 54b disposed thereon are provided for every 10 stacked layers, and If the width dimension W of the three strips 533a and 533b is made equal to the width dimension in the stacking direction of one cell 21, the local current of the fuel cell 20 can be measured with high accuracy, and further, the fuel cell 20 can be measured with high accuracy. It is known that the operating state can be detected.

(Third embodiment)
In the above-described embodiment, an example in which the magnetic material cores 51 and 52 formed in a substantially U-shape has been described, but in this embodiment, as viewed from the stacking direction of the cells 21 as illustrated in FIG. A hydrogen-side magnetic material core 51 and an air-side magnetic material core 52 that are sometimes formed in an annular shape are employed. FIG. 7 is an enlarged perspective view of the main parts of the fuel cell 20 and the local current measuring device 10 in the present embodiment, corresponding to FIG. 2 of the first embodiment.

  Specifically, the hydrogen-side magnetic material core 51 and the air-side magnetic material core 52 of the present embodiment are formed of substantially plate-shaped plate members when viewed from the stacking direction of the cells 21, In the state where one side of the mouth shape is exposed to the outside of the fuel cell 20, the remaining portion is arranged between the cells 21 so as to overlap with the cells 21. In addition, the predetermined area | region which the hydrogen side magnetic material core 51 and the air side magnetic material core 52 surround is the same as that of 1st Embodiment.

  Also, in each of the hydrogen-side magnetic material core 51 and the air-side magnetic material core 52, the hydrogen-side magnetic sensor 54 a and the air-side magnetic sensor 54 b that are the same as those in the first embodiment are provided at portions exposed to the outside of the fuel cell 20. Is arranged. Therefore, in the present embodiment, the magnetic flux collecting cores 53a and 53b of the first and second embodiments are abolished.

  Furthermore, the hydrogen side magnetic sensor 54a and the air side magnetic sensor 54b of this embodiment are provided in the same number as the hydrogen side magnetic material core 51 and the air side magnetic material core 52, respectively. Other configurations and operations are the same as those in the first embodiment. Therefore, also in the local current measuring device 10 of the present embodiment, the local current of the fuel cell 20 can be measured with a simple configuration and high accuracy as in the first embodiment.

  Moreover, in the present embodiment, the magnetic flux collecting cores 53a and 53b can be abolished, and the hydrogen side directly at the part exposed to the outside of the fuel cell 20 in the hydrogen side magnetic material core 51 and the air side magnetic material core 52. Since the strength of the magnetic field formed in the magnetic material core 51 and the air side magnetic material core 52 can be detected, the local current measuring device 10 can be further simplified.

(Fourth embodiment)
An embodiment of the fuel cell diagnostic device 60 according to the present invention will be described with reference to FIGS. FIG. 8 is a schematic overall configuration diagram of the fuel cell 20 to which the fuel cell diagnostic device 60 of the present embodiment is applied, and corresponds to FIG. 1 of the first embodiment. In addition, in this embodiment, the same code | symbol is attached | subjected about the part equivalent or equivalent to the 1st-3rd embodiment mentioned above, and the description is abbreviate | omitted or simplified and demonstrated.

  As shown in FIG. 8, the fuel cell diagnostic apparatus 60 of the present embodiment includes magnetic material cores 61 and 62, a voltage sensor 31, a current sensor 32, and a control device 40 ( The fuel cell diagnostic means 40b) is provided.

  First, the arrangement | positioning with respect to the cell 21 of the magnetic material cores 61 and 62 of this embodiment is demonstrated based on FIG. 9, FIG. FIG. 9 is an enlarged perspective view of a main part of the fuel cell diagnostic device 60 of the present embodiment, and FIG. 10 is an enlarged view of part B of FIG.

  As shown in FIG. 9, in this embodiment, as the magnetic material cores 61 and 62, a fuel gas side magnetic material core (hydrogen side magnetic material core) 61 and an oxidant gas side magnetic material core (air side magnetic material core) 62 are used. There are two types. The hydrogen-side magnetic material core 61 is disposed so as to surround a first region (region close to the hydrogen outlet hole 211b) including the vicinity of the fuel gas-side outlet that allows hydrogen to flow out of the cell 21. The air-side magnetic material core 62 is disposed so as to surround a second region (region close to the air outlet hole 212b) including the vicinity of the oxidant gas-side outlet that allows air to flow out of the cell 21.

  Both magnetic material cores 61 and 62 are each formed of a substantially U-shaped plate-like member when viewed from the stacking direction of the cells 21. When viewed from the stacking direction of the cells 21, both the magnetic material cores 61 and 62 have two end portions 61 a, 61 b, 62 a and 62 b on the open end side of the U-shape outside the fuel cell 20. In the exposed state, the remaining portion is arranged in the cooling water flow path 233 between the cells 21 so as to overlap with the cells 21.

  And the part which overlaps with the cell 21 of the hydrogen side magnetic material core 61 is arrange | positioned so that the 1st area | region of the cell 21 may be enclosed by three U-shaped three sides when it sees from the lamination direction of the cell 21. Yes. In addition, the portion of the air-side magnetic material core 62 that overlaps with the cell 21 is disposed so as to surround the second region of the cell 21 with three U-shaped sides when viewed from the stacking direction of the cell 21. Yes. In the present embodiment, similarly to the first embodiment, when viewed from the stacking direction of the cells 21, the first region (including the vicinity of the fuel gas side outlet) and the second region (oxidant gas) are used. Both magnetic material cores 61 and 62 are arranged so that the region including the vicinity of the side outlet portion does not overlap each other.

  Specifically, the hydrogen-side magnetic material core 61 has an edge-side tip 61a that extends along the edge of the cell 21 out of the two tips 61a, 61b on the open end side of the U-shape. It extends to the outside of the fuel cell 20 with respect to the center side tip 61b located on the side. In other words, the center side tip portion 61b has a shorter length than the edge side tip portion 61a.

  Similarly, the air-side magnetic material core 62 has an edge-side tip 62b extending along the edge of the cell 21 out of the two tips 62a, 62b on the open end side of the U-shape. It extends to the outside of the fuel cell 20 with respect to the center-side tip 62a located at the position. In other words, the center side front end portion 62a has a shorter length than the edge side front end portion 62b.

  Further, the hydrogen-side magnetic material cores 61 arranged in the plurality of cells 21 are magnetically connected to each other at the edge-side tip portions 61a via the first hydrogen-side magnetism collecting portion 64a, and the center-side tip portion 61b. The two are magnetically connected to each other through the second hydrogen-side magnetic flux collector 64b.

  The first hydrogen side magnetic flux collector 64a and the second hydrogen side magnetic flux collector 64b of the present embodiment extend in the stacking direction of the cells 21 and magnetically connect the plurality of hydrogen side magnetic material cores 61 to each other. A fuel gas side magnetic collecting core (hydrogen side magnetic collecting core) 64 that collects and passes magnetic fluxes passing through the hydrogen side magnetic material core 61 is configured. The first hydrogen-side magnetic flux collector 64a and the second hydrogen-side magnetic flux collector 64b are each formed of the same magnetic material as the magnetic material cores 61 and 62.

  On the other hand, the air-side magnetic material cores 62 disposed in the plurality of cells 21 are magnetically connected to each other at the center end portions 62a via the first air-side magnetic flux collecting portions 65a, and the edge-side end portions 62b. The two are magnetically connected to each other through the second air-side magnetic flux collector 65b.

  The first air side magnetic flux collector 65a and the second air side magnetic flux collector 65b of the present embodiment extend in the stacking direction of the cells 21, and magnetically connect the plurality of air side magnetic material cores 62 to each other. An oxidant gas side magnetic flux collecting core (air side magnetic flux collecting core) 65 that collects and passes the magnetic flux passing through the air side magnetic material core 62 is configured. The first air-side magnetic flux collector 65a and the second air-side magnetic flux collector 65b are each made of the same magnetic material as the magnetic material cores 61 and 62.

  Further, the center side tip portions 61b and 62a of the hydrogen side magnetic material core 61 and the air side magnetic material core 62 are connected to the connecting core 63 via the second hydrogen side magnetic flux collector 64b and the first air side magnetic flux collector 65a. Is magnetically connected to On the other hand, the edge-side tip portions 61a and 62b of the hydrogen-side magnetic material core 61 and the air-side magnetic material core 62 are connected to the connecting core 63 via the first hydrogen-side magnetic flux collector 64a and the second air-side magnetic flux collector 65b. Magnetically connected.

  The connecting core 63 includes a first connecting part 63a that magnetically connects the second hydrogen side magnetic collecting part 64b and the first air side magnetic collecting part 65a, and the first hydrogen side magnetic collecting part 64a and the second air side. The magnetic flux collector 65 is configured to have a second connecting portion 63b that magnetically connects the magnetic flux collecting portions 65b.

  The first connecting portion 63a and the second connecting portion 63b are each formed in a T shape, and when viewed from the stacking direction of the cells 21, they are substantially H-shaped through a magnetic sensor 66 described later. Magnetically connected.

  And between the 1st connection part 63a and the 2nd connection part 63b, the magnetic sensor 66 as a magnetic field strength detection means is arrange | positioned. The magnetic sensor 66 detects the strength of the magnetic field formed between the first connecting portion 63a and the second connecting portion 63b of the connecting core 63 during power generation of the fuel cell 20. In the present embodiment, a Hall element is employed as the magnetic sensor 66. Note that the magnetic sensor 66 of the present embodiment is configured to output the magnetic flux passing from the first connecting portion 63a to the second connecting portion 63b as positive.

  Here, the magnetic flux passing through the hydrogen-side magnetic material core 61 and the air-side magnetic material core 62 when a current flows in the stacking direction of the cells 21 by the power generation of the fuel cell 20 will be described with reference to FIG. FIG. 11 is a front view of the fuel cell diagnostic device 60 as viewed from the stacking direction.

  As shown in FIG. 11, when a current flows in the stacking direction of the cells 21 (the direction from the front side to the back side of the paper), the magnetic strength of the hydrogen-side magnetic material core 61 in the direction of the arrow on the alternate long and short dash line shown in FIG. φ1 magnetic flux passes. Further, when a current flows in the stacking direction of the cells 21 (the direction from the front side to the back side of the paper), the magnetic flux of the magnetic field strength φ2 flows in the air-side magnetic material core 62 in the direction of the arrow on the two-dot chain line shown in FIG. pass.

  At this time, at the portion of the connecting core 63 where the magnetic sensor 66 is disposed (between the first connecting portion 63a and the second connecting portion 63b), the hydrogen-side magnetic material core 61 passes through the first connecting portion 63a. While the magnetic flux passes, the magnetic flux from the air-side magnetic material core 62 passes through the second connecting portion 63b. That is, the connecting core 63 is connected such that the direction of the magnetic flux from the hydrogen side magnetic material core 61 side and the direction of the magnetic flux from the air side magnetic material core 62 side are opposite.

  For this reason, the connecting core 63 acts so that the magnetic flux from the hydrogen side magnetic material core 61 and the magnetic flux from the air side magnetic material core 62 cancel each other. Therefore, the magnetic sensor 66 detects the deviation Δφ (= φ1-φ2) between the magnetic field strength on the hydrogen side magnetic material core 61 side and the magnetic field strength on the air side magnetic material core 62 side.

  Also, as shown in FIG. 10, between the plurality of air-side magnetic material cores 62 (center-side tip 62a) and the first air-side magnetic flux collector 65a, and between the plurality of air-side magnetic material cores 62 (edge-side tip). 62b) and the second air-side magnetic flux collector 65b, a resin film 67 is interposed between the air-side magnetic material core 62 and the air-side magnetic flux collectors 65a, 65b. Yes. Similarly, between the plurality of hydrogen side magnetic material cores 61 (edge side tip portion 61a) and the first hydrogen side magnetic flux collecting portion 64a, and between the plurality of hydrogen side magnetic material cores 61 (center side tip portion 61b) and the second hydrogen. A resin film 67 is interposed between the side magnetic flux collector 64b, and the hydrogen side magnetic material core 61 and the hydrogen side magnetic flux collectors 64a and 64b are electrically insulated.

  Thereby, even if each magnetic material core 61 and 62 and each magnetism collection part 64a, 64b, 65a, 65b are connected directly, electric power short-circuits between each magnetic material core 61 and 62 (short circuit). Can be prevented. A short circuit between the magnetic material cores 61 and 62 may be prevented by providing a gap or the like in addition to the resin film 67 between the magnetic material cores 61 and 62 and the magnetic flux collecting cores 64 and 65. .

  Next, the control device 40 of the present embodiment controls various control devices connected to the output side, and determines the operating state of the fuel cell 20 based on the output signal (detected value) output from the magnetic sensor 66. Diagnose. The control device 40 of the present embodiment is configured such that control means for controlling various control devices and diagnosis means for diagnosing the operating state of the fuel cell 20 are integrally configured. The hardware and software constituting the diagnostic means for diagnosing the 20 operating states are defined as fuel cell diagnostic means 40b (see FIG. 8). Of course, the fuel cell diagnostic means 40b may be configured separately from the control device 40.

  Therefore, the fuel cell diagnostic device 60 of the present embodiment includes the voltage sensor 31, the current sensor 32, the hydrogen side magnetic material core 61, the air side magnetic material core 62, the connection core 63, the hydrogen side magnetic flux collecting core 64, and the air side magnetic flux collection. The core 65, the magnetic sensor 66, and the fuel cell diagnostic means 40b are configured.

  Next, the operation of the fuel cell diagnostic apparatus 60 of the present embodiment having the above configuration will be described with reference to FIG. FIG. 12 is a flowchart showing a control process in the control device 40 (fuel cell diagnostic means 40b) of the present embodiment. The flowchart of FIG. 12 is executed at predetermined control cycles as a subroutine of a main routine executed by the control device 40 to cause the fuel cell 20 to generate electric power and output electric energy.

  First, in step S11, detection signals from the voltage sensor 31, the current sensor 32, and the magnetic sensor 66 are read.

  In subsequent step S12, it is determined whether or not the internal resistance R of the fuel cell 20 as a whole is equal to or greater than a predetermined reference internal resistance KR. Note that the internal resistance R of the fuel cell 20 as a whole is calculated based on the detection signal of the voltage sensor 31 and the detection signal of the current sensor 32 as in the first embodiment.

  In step S12, when R ≧ KR, it is assumed that the dry-up state is established, and the process proceeds to step S13. In step S13, it is displayed on the display panel 41 that it is a dry-up state, and it progresses to step S14. On the other hand, when R ≧ KR is not satisfied, it is determined that the dry-up state is not established, and the process proceeds to step S14.

  In step S14, it is determined whether or not the detected value Δφ of the magnetic sensor 66 is smaller than a preset first reference value φHo. The first reference value φHo is detected when, for example, the flow rate of hydrogen (fuel gas) supplied to the fuel cell 20 is forcibly reduced to make the operating state of the fuel cell 20 a fuel gas shortage state. It may be determined based on the detected value of the magnetic sensor 66.

  Here, if the fuel gas shortage state in which the flow rate of hydrogen supplied to the fuel cell 20 is insufficient, the hydrogen-side local current AH in the region including the vicinity of the fuel gas-side outlet portion is reduced. Along with this, there is a bias between the strength of the magnetic field generated in the hydrogen-side magnetic material core 61 and the strength of the magnetic field generated in the air-side magnetic material core 62. That is, the magnetic field strength φ1 generated in the hydrogen-side magnetic material core 61 decreases, and the detection value Δφ (= φ1-φ2) of the magnetic sensor 66 decreases. Therefore, whether or not the fuel cell 20 is in a fuel gas shortage state can be determined based on the magnitude of the detected value Δφ of the magnetic sensor 66.

  Therefore, in this embodiment, when Δφ <φHo is satisfied in step S14, that is, the magnetic field strength in the hydrogen-side magnetic material core 61 is higher than the magnetic field strength in the air-side magnetic material core 62. If it is smaller than the value φHo, it is determined that the fuel gas is insufficient, and the process proceeds to step S15. In step S15, the fact that the fuel gas is insufficient is displayed on the display panel 41, and the process returns to the main routine. On the other hand, when Δφ <φHo is not satisfied, it is determined that the fuel gas is not insufficient, and the process proceeds to step S16.

  In step S16, it is determined whether or not the detected value Δφ of the magnetic sensor 66 is greater than a preset second reference value φAo. Note that the second reference value φAo is, for example, forcibly reducing the flow rate of air (oxidant gas) supplied to the fuel cell 20 and setting the operating state of the fuel cell 20 to an oxidant gas shortage state. What is necessary is just to determine based on the detected value of the detected magnetic sensor 66.

  Here, when an oxidant gas shortage state in which the flow rate of air supplied to the fuel cell 20 is insufficient, the air-side local current AAir in a region including the vicinity of the oxidant gas-side outlet portion decreases. Accordingly, the magnetic field strength φ2 generated in the air-side magnetic material core 62 decreases, and the detection value Δφ (= φ1-φ2) of the magnetic sensor 66 increases. Therefore, it is possible to determine whether or not the fuel cell 20 is in an oxidant gas shortage state based on the magnitude of the detection value Δφ of the magnetic sensor 66.

  Therefore, in this embodiment, when Δφ> φAo is satisfied in step S16, it is determined that the oxidant gas is in a shortage state, and the process proceeds to step S17. In step S17, it is displayed on the display panel 41 that the oxidant gas is insufficient, and the process returns to the main routine. On the other hand, when Δφ> φAo is not satisfied, it is determined that the oxidant gas is not insufficient, and the process returns to the main routine.

  In the fuel cell diagnostic apparatus 60 of the present embodiment described above, the hydrogen-side magnetic material is such that the direction of the magnetic flux from the hydrogen-side magnetic material core 61 and the direction of the magnetic flux from the air-side magnetic material core 62 are opposite. The core 61 and the air-side magnetic material core 62 are magnetically connected by a connecting core 63. For this reason, the connecting core 63 acts so that the magnetic flux from the hydrogen side magnetic material core 61 and the magnetic flux from the air side magnetic material core 62 cancel each other. Therefore, by detecting with the magnetic sensor 66 that detects the strength of the magnetic field in the connecting core 63, a deviation between the strength of the magnetic field in the hydrogen-side magnetic material core 61 and the strength of the magnetic field in the air-side magnetic material core 62 is detected. be able to.

  When some of the cells 21 in the fuel cell 20 are in a fuel gas shortage state or an oxidant gas shortage state, the magnetic field strength generated in the hydrogen-side magnetic material core 61 and the magnetic field strength generated in the air-side magnetic material core 62 are reduced. Therefore, based on the detection value of the magnetic sensor 66, it is possible to diagnose the operating state of the fuel cell 20 such as a fuel gas shortage state or an oxidant gas shortage state.

  At this time, the magnetic sensor 66 can detect the bias of the magnetic field strength generated in each of the magnetic material cores 61 and 62 by detecting the strength of the magnetic field in the connecting core 63. , 62 need not be provided with a plurality of magnetic sensors. Accordingly, the configuration of the fuel cell diagnostic device 60 can be simplified.

  Further, the magnetic sensor 66 of the present embodiment detects the strength of the magnetic field by the magnetic flux passing through the connecting core 63 that connects the portions exposed to the outside of the fuel cell 20 among the magnetic material cores 61 and 62. The magnetic sensor 66 can be arranged outside the fuel cell 20 and the output can be easily taken out. Therefore, the configuration of the fuel cell diagnostic device 60 can be further simplified as compared with the case where the magnetic sensor 66 is disposed between the stacked cells 21.

  Further, in the present embodiment, since the magnetic material cores 61 and 62 are arranged so as to overlap with the cell 21 when viewed from the stacking direction of the cells 21, the magnetic material cores 61 and 62 are arranged. The magnetic field formed in each magnetic material core 61, 62 becomes stronger than the case where the whole is disposed outside the cell 21. Therefore, the operating state of the fuel cell 20 can be diagnosed with high accuracy.

  Furthermore, in this embodiment, since the magnetic flux collecting cores 64 and 65 collect and pass the magnetic flux between the magnetic material cores 61 and 62, the amount of magnetic flux passing through the connecting core 63 can be increased. It becomes possible to diagnose the operating state of the fuel cell 20 with higher accuracy.

  As a result, according to the fuel cell diagnostic device 60 of the fuel cell 20 of the present embodiment, the operation state of the fuel cell 20 can be diagnosed with a simple configuration and high accuracy.

  In the present embodiment, the magnetic sensor 66 is configured to output the magnetic flux passing from the first connecting portion 63a to the second connecting portion 63b as positive, but from the second connecting portion 63b to the first connecting portion. You may comprise so that the magnetic flux which passes to the part 63a may be output as positive.

  In this case, the detected value Δφ by the magnetic sensor 66 is a value obtained by subtracting the magnetic field strength φ1 on the hydrogen side magnetic material core 61 side from the magnetic field strength φ2 on the air side magnetic material core 62 side (Δφ = φ2-φ1). For this reason, in the determination process in step 14, it is determined whether or not the detected value Δφ of the magnetic sensor 66 is larger than the first reference value φHo. If Δφ> φHo, the fuel gas shortage state occurs. As a result, the process proceeds to step S15. In the determination process in step 16, it is determined whether or not the detected value Δφ of the magnetic sensor 66 is smaller than the second reference value φAo. If Δφ <φAo, the oxidant gas is in a shortage state. As a result, the process proceeds to step S17.

(Fifth embodiment)
In the above-described fourth embodiment, the example in which the configuration in which the magnetic flux passing through the plurality of magnetic material cores 61 and 62 is collected using the hydrogen-side magnetic flux collecting core 64 and the air-side magnetic flux collecting core 65 has been described. However, the present invention is not limited to this. That is, without using the hydrogen-side magnetic flux collecting core 64 and the air-side magnetic flux collecting core 65, the connecting core 63 is magnetically connected to each of the magnetic material cores 61 and 62, and the strength of the magnetic field in the connecting core 63 is determined magnetically. You may make it detect with the sensor 66. FIG.

  According to this, since the configuration such as the hydrogen-side magnetic collecting core 64 and the air-side magnetic collecting core 65 becomes unnecessary, the number of parts of the fuel cell diagnostic device 60 is reduced, and the fuel cell diagnostic device 60 is simplified. It becomes possible.

  Further, in this case, the configuration such as the hydrogen-side magnetic core 64 and the air-side magnetic core 65 is not required, so that the center-side tips of the hydrogen-side magnetic material core 61 and the air-side magnetic material core 62 as shown in FIG. When viewed from the stacking direction of the cells 21, the portions 61 b and 62 a are polymerized with the cells 21, and the edge-side tip portions 61 a and 62 b of the hydrogen side magnetic material core 61 and the air side magnetic material core 62 are exposed to the outside of the fuel cell 20. It is good also as a structure. FIG. 13 is a front view of the fuel cell diagnostic device 60 according to the present embodiment as viewed from the stacking direction, and corresponds to FIG. 11 of the fourth embodiment.

  According to this, since the center side tips 61b and 62a of the hydrogen side magnetic material core 61 and the air side magnetic material core 62 are not exposed to the outside of the fuel cell 20, the size of the fuel cell diagnostic device 60 can be reduced. Is possible.

(Sixth embodiment)
In the above-described fourth embodiment, the hydrogen-side magnetic flux collecting core 64b, the air-side magnetic flux collecting core 65a, and the first connecting portion 63a of the connecting core 63 are configured separately, and the hydrogen-side magnetic flux collecting core 64a and the air-side magnetic flux collecting core. Although the example which employ | adopted what comprised the core 65b and the 2nd connection part 63b of the connection core 63 by another body was demonstrated, it is not limited to this. That is, the hydrogen-side magnetic flux collecting core 64b, the air-side magnetic flux collecting core 65a, and the first coupling portion 63a of the coupling core 63 are integrally formed, and the hydrogen-side magnetic flux collecting core 64a, the air-side magnetic flux collecting core 65b, and the coupling core 63 are integrated. The second connecting portion 63b may be integrally formed.

  For example, in 4th Embodiment, the both ends connected to each magnetic flux collection cores 64 and 65 in the 1st connection part 63a and the 2nd connection part 63b of the connection core 63 are extended in the lamination direction, and the extended site | part is used. As shown in FIG. 14, the magnetic material cores 61 and 62 may be magnetically connected to the tip portions 61a, 61b, 62a, and 62b. In this case, each of the first connection portion 63a and the second connection portion 63b of the connection core 63 is substantially T-shaped when viewed from the stacking direction of the cells 21, and substantially when viewed from the direction orthogonal to the stacking direction of the cells 21. It is formed in an H shape. FIG. 14 is an enlarged perspective view of a main part of the fuel cell diagnostic device 60 of the present embodiment, corresponding to FIG. 9 of the fourth embodiment.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and can be variously modified as follows without departing from the spirit of the present invention.

  (1) In the above-described embodiment, the magnetic material cores 51, 52, 61, 62 are arranged between all adjacent cells 21, but the arrangement of the magnetic material cores 51, 52, 61, 62 is this. It is not limited to. The magnetic material cores 51, 52, 61, and 62 may be arranged between a predetermined number of cells 21 among adjacent cells 21.

  In the first to third embodiments described above, two types of magnetic material cores, that is, the hydrogen side magnetic material core 51 and the air side magnetic material core 52 are provided, but the magnetic material core is not limited to this. That is, only one of the hydrogen side magnetic material core 51 and the air side magnetic material core 52 may be provided. Furthermore, another magnetic material core arranged so as to surround a region where the local current changes according to a change in the operating state of the fuel cell 20 may be provided.

  (2) In the above-described embodiment, the example in which the substantially U-shaped or substantially mouth-shaped magnetic material cores 51, 52, 61, 62 are used when viewed from the stacking direction of the cells 21 has been described. The shape of the magnetic material cores 51, 52, 61, 62 is not limited to this. That is, it is not necessary to surround the predetermined region with a linear portion as in the above-described embodiment, and the predetermined region may be surrounded with a curved portion.

  Therefore, when the two end portions on the open end side of the magnetic material cores 51, 52, 61, 62 are exposed to the outside of the fuel cell 20, when viewed from the stacking direction of the cells 21, It is good also as a letter shape. In the first to third embodiments, when the magnetic material cores 51 and 52 are formed in an annular shape, the magnetic material cores 51 and 52 may have a circular shape, an elliptical shape, or the like when viewed from the stacking direction of the cells 21.

  (3) In the above-described embodiment, the example in which the magnetic sensors 54a, 54b, and 66 made of Hall elements are used as the magnetic field strength detecting means has been described. However, other types of magnetic sensors are used as the magnetic sensors 54a, 54b, and 66. May be. For example, an MI element, an AMR element, an MR element, a flux gate, or the like may be employed as the magnetic field strength detection means.

  (4) In the above-described embodiment, the example in which the magnetic material cores 51, 52, 61, 62, the magnetic flux collecting cores 53a, 53b, 64, 65, and the connecting core 63 formed of permalloy have been described. As the cores 51, 52, 61, 62, the magnetic flux collecting cores 53a, 53b, 64, 65, and the connecting core 63, silicon steel, amorphous, mu metal, permendur, or the like may be adopted.

  (5) In the first and second embodiments described above, each magnetic material is provided by interposing the resin films 55a and 55b, which are insulating members, between the magnetic material cores 51 and 52 and the magnetic flux collecting cores 53a and 53b. The cores 51 and 52 are electrically insulated from each other to prevent the power output from the cell 21 from being short-circuited between the magnetic material cores 51 and 52. Of course, the resin film 55a , 55b may be interposed.

  Furthermore, you may interpose an insulator like a resin film between the magnetic material cores 51 and 52 and the cell 21 arrange | positioned adjacently. According to this, even if the magnetic material cores 51 and 52 and the magnetic flux collecting cores 53a and 53b are directly connected, it is possible to prevent power from being short-circuited between the magnetic material cores 51 and 52.

  (6) In the above-described embodiment, when the control device 40 detects an operation state such as the fuel gas shortage state, the oxidant gas shortage state, or the dry-up state of the fuel cell 20, this is displayed on the display panel 41. Of course, other controls may be performed.

  For example, when the fuel gas shortage state is detected, the control device 40 increases the supply amount of the fuel gas, and when the fuel gas shortage state is detected, the control device 40 increases the supply amount of the oxidant gas, Furthermore, when the dry-up state is detected, the control device 40 may control the operation of various actuators so as to increase the humidification amount.

  (7) In the above-described embodiment, the example in which the present invention is applied to the fuel cell 20 mounted on the vehicle has been described. However, the application of the present invention is not limited to this. For example, the present invention may be applied to a fuel cell mounted on a moving body such as a ship or an airplane, or may be applied to a fuel cell mounted on a stationary power generator.

  (8) In the above embodiment, an example in which a solid polymer electrolyte fuel cell (PEMFC) is adopted as the fuel cell 20 has been described. However, the application of the present invention is not limited to this. For example, a phosphoric acid fuel cell (PAFC), a solid oxide fuel cell (SOFC), an alkaline fuel cell (AFC), or the like may be used as the fuel cell 20.

DESCRIPTION OF SYMBOLS 10 Local current measuring apparatus 20 Fuel cell 21 Cell 40b Fuel cell diagnostic means (diagnosis means)
51 Hydrogen-side magnetic material core 51a, 51b Tip 52 Air-side magnetic material core 52a, 52b Tip 53a Hydrogen-side magnetic core 53b Air-side magnetic core 531a, 531b First strip 532a, 532b Second strip 533a, 533b Third strip 54a Hydrogen side magnetic sensor 54b Air side magnetic sensor 60 Fuel cell diagnostic device 61 Hydrogen side magnetic material core (fuel gas side magnetic material core)
62 Air side magnetic material core (oxidant gas side magnetic material core)
63 Linking core 64 Hydrogen side magnetic core (fuel gas side magnetic core)
65 Air-side magnetic core (oxidant gas-side magnetic core)
66 Magnetic sensor (magnetic field strength detection means)

Claims (14)

A local current measuring device for measuring a current flowing locally in a fuel cell (20) in which a plurality of cells (21) that generate electricity by electrochemically reacting an oxidant gas and a fuel gas are laminated,
When viewed from the stacking direction of the cell (21), at least a part of the magnetic material core is superposed with the cell (21), and is made of a magnetic material disposed so as to surround a predetermined region of the cell (21). (51, 52),
Magnetic field strength detecting means (54a, 54b) for detecting the strength of the magnetic field formed on the magnetic material core (51, 52),
A part of the magnetic material core (51, 52) is exposed to the outside of the fuel cell (20),
The magnetic field strength detection means (54a, 54b) detects the strength of the magnetic field by a magnetic flux passing through a portion of the magnetic material core (51, 52) exposed to the outside of the fuel cell (20). A fuel cell local current measuring device. The predetermined area is an area including the vicinity of a fuel gas side outlet for allowing the fuel gas to flow out of the cell (21).
The fuel cell according to claim 1, wherein a fuel gas side magnetic material core (51) is provided as the magnetic material core so as to surround a region including the vicinity of the fuel gas side outlet portion. Local current measuring device. The predetermined region is a region including the vicinity of an oxidant gas side outlet that allows the oxidant gas to flow out of the cell (21).
The oxidant gas side magnetic material core (52) disposed so as to surround a region including the vicinity of the oxidant gas side outlet portion is provided as the magnetic material core. A local current measuring device for a fuel cell as described. The magnetic material cores (51, 52) are formed in a U shape when viewed from the stacking direction, and two tip portions (51a, 51b, 52a) on the open end side of the U shape. , 52b) are exposed to the outside of the fuel cell (20),
Further, the two tip portions (51a ... 52b) are magnetically connected to each other, and one tip portion (51a ... 52b) and the other tip portion (51a ...) of the two tip portions (51a ... 52b). 52b) including magnetic flux collecting cores (53a, 53b) made of a magnetic material that allows magnetic flux between them to pass through.
4. The magnetic field strength detection means (54 a, 54 b) is disposed in the magnetic flux collecting core (53 a, 53 b) to detect the strength of the magnetic field. 5. Local current measuring device for fuel cell. A plurality of the magnetic material cores (51, 52) are provided,
The magnetic flux collecting cores (53a, 53b) pass between the one tip portion (51a ... 52b) and the other tip portion (51a ... 52b) in the plurality of magnetic material cores (51, 52). 5. The local current measuring device for a fuel cell according to claim 4, wherein the magnetic fluxes are gathered and passed. The magnetic flux collecting cores (53a, 53b)
First strips (531a, 531b) extending in the stacking direction and magnetically connecting the one end portions (51a ... 52b) of the plurality of magnetic material cores (51, 52),
A second strip (532a, 532b) extending in the stacking direction and magnetically connecting the other tip portions (51a ... 52b) of the plurality of magnetic material cores (51, 52),
And a third belt-like portion (533a, 533b) for magnetically connecting the first belt-like portion (531a, 531b) and the second belt-like portion (532a, 532b),
The width dimension (W) in the stacking direction of the third strips (533a, 533b) is the length dimension (L1) in the stacking direction of the first strips (531a, 531b) and the second strip ( The local current measuring device for a fuel cell according to claim 5, characterized in that it is shorter than the length dimension (L2) in the stacking direction of 532a, 532b).   The local current measuring device for a fuel cell according to claim 6, wherein a plurality of the third strips (533a, 533b) are provided.   The fuel cell according to any one of claims 4 to 7, wherein the magnetic material core (51, 52) and the magnetic flux collecting core (53a, 53b) are electrically insulated. Local current measurement device.   The fuel cell according to any one of claims 1 to 3, wherein the magnetic material core (51, 52) is formed in an annular shape when viewed from the stacking direction of the cells (21). Local current measuring device. A fuel cell diagnostic device for diagnosing the operating state of a fuel cell (20) in which a plurality of cells (21) that generate electricity by electrochemical reaction of an oxidant gas and a fuel gas are stacked,
Magnetic field strength detection means (66) for detecting the strength of the magnetic field;
When viewed from the stacking direction of the cells (21), at least a part of the cells (21) is superposed with the cells (21) and includes a fuel gas side outlet vicinity that allows the fuel gas to flow out of the cells (21). A fuel gas side magnetic material core (61) made of a magnetic material arranged so as to surround the region of
When viewed from the stacking direction of the cell (21), at least part of the cell (21) is superposed with the cell (21) and includes the vicinity of the oxidant gas side outlet for allowing the oxidant gas to flow out of the cell (21). An oxidant gas side magnetic material core (62) made of a magnetic material arranged so as to surround the second region;
A connecting core (63) made of a magnetic material that allows magnetic flux between the fuel gas side magnetic material core (61) and the oxidant gas side magnetic material core (62) to pass;
Diagnostic means (40b) for diagnosing the operating state of the fuel cell (20) based on the detection value of the magnetic field strength detection means (66),
The connecting core (63) is configured such that the direction of magnetic flux from the fuel gas side magnetic material core (61) and the direction of magnetic flux from the oxidant gas side magnetic material core (62) are opposite to each other. , And are magnetically connected to the fuel gas side magnetic material core (61) and the oxidant gas side magnetic material core (62), respectively.
The magnetic field strength detection means (66) detects the strength of the magnetic field in the connection core (63) by a magnetic flux disposed on the connection core (63) and passing through the connection core (63). A fuel cell diagnostic device. Each of the fuel gas side magnetic material core (61) and the oxidant gas side magnetic material core (62) is partially exposed to the outside of the fuel cell (20) when viewed from the stacking direction. ,
The connecting core (63) magnetically connects portions of the fuel gas side magnetic material core (61) and the oxidant gas side magnetic material core (62) exposed to the outside of the fuel cell (20). The fuel cell diagnostic device according to claim 10, wherein the fuel cell diagnostic device is connected. Each of the fuel gas side magnetic material core (61) and the oxidant gas side magnetic material core (62) is disposed in a plurality of the cells (21),
Extending in the stacking direction, magnetically connecting each of the plurality of fuel gas side magnetic material cores (61) to collect and pass the magnetic flux passing through the plurality of fuel gas side magnetic material cores (61). A fuel gas side magnetic core (64);
A plurality of the oxidant gas side magnetic material cores (62) extending in the stacking direction are magnetically connected, and magnetic fluxes passing through the plurality of oxidant gas side magnetic material cores (62) are assembled. An oxidant gas side magnetic flux collecting core (65) to be passed,
The connecting core (63) is connected to the fuel gas side magnetic material core (61) and the oxidant gas side via the fuel gas side magnetic core (64) and the oxidant gas side magnetic core (65). The fuel cell diagnostic apparatus according to claim 11, wherein the magnetic material core (62) is configured by magnetically connecting portions exposed to the outside of the fuel cell (20). The fuel gas side magnetic material core (61) and the fuel gas side magnetic core (64) are electrically insulated,
The fuel cell diagnostic apparatus according to claim 12, wherein the oxidant gas side magnetic material core (62) and the oxidant gas side magnetic flux collecting core (65) are electrically insulated. The diagnostic means (40b)
Based on the detection value of the magnetic field strength detection means (66), the magnitude of the magnetic field strength in the fuel gas side magnetic material core (61) and the oxidant gas side magnetic material core (62) is determined,
When it is determined that the strength of the magnetic field in the fuel gas side magnetic material core (61) is smaller than a predetermined first reference value than the strength of the magnetic field in the oxidant gas side magnetic material core (62). , Diagnose that the fuel gas is insufficient,
When it is determined that the strength of the magnetic field in the oxidant gas side magnetic material core (62) is smaller than a predetermined second reference value than the strength of the magnetic field in the fuel gas side magnetic material core (61). 14. The fuel cell diagnostic apparatus according to claim 10, wherein the diagnosis is made as a state where the oxidant gas is insufficient.

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