JP4817962B2 - Fuel cell current distribution measuring device, stacked fuel cell current distribution measuring device, and fuel cell current distribution measuring method - Google Patents

Description

  The present invention relates to a fuel cell current distribution measuring apparatus and a fuel cell current distribution measuring method for obtaining an electromotive force distribution on an electrode surface of a fuel cell having an electrolyte and a pair of electrodes provided on both sides of the electrolyte.

  Fuel cells that use chemical reactions of gases to convert chemical energy directly into electrical energy have high power generation efficiency because they are not constrained by Carnot efficiency, and the exhausted gas is clean and has little impact on the environment. Therefore, in recent years, various uses such as power generation and low-pollution automobile power supplies are expected. Fuel cells can be classified according to their electrolytes. For example, phosphoric acid fuel cells, molten carbonate fuel cells, solid electrolyte fuel cells, solid polymer fuel cells, and the like are known.

  In general, as shown in FIG. 10, a fuel cell has an electrode-electrolyte structure having an electrolyte 101 and a pair of electrodes (a fuel electrode 102 and an oxidizer electrode 103) provided on both sides thereof as a power generation unit. A fuel gas such as hydrogen or hydrocarbon is supplied to 102, an oxidant gas such as oxygen or air is supplied to the oxidant electrode 103, and the gas, the electrolyte 101, and the electrodes (fuel electrode 102 and oxidant electrode 103) Electricity is taken out by causing an electrochemical reaction to proceed at the three-phase interface.

  In a fuel cell, it is important that the electrode reaction proceeds uniformly throughout the electrode-electrolyte structure. However, depending on the location of the electrode-electrolyte structure, the amount of moisture in the electrolyte, the degree of deterioration of the electrolyte, the hydrogen concentration in the fuel gas, the oxygen concentration in the air, etc. The electrode reaction may not proceed uniformly. That is, there may be a difference in the degree of electrode reaction for each part of the electrode-electrolyte structure.

  Therefore, by grasping the degree of electrode reaction in each part of the electrode-electrolyte structure, optimization of components such as electrolyte and electrode catalyst, and optimization of the humidification amount of fuel gas and oxidant gas, etc. Furthermore, it is possible to know the cause of deterioration of the electrode-electrolyte structure, the progress of deterioration, and the like. Therefore, it is necessary to investigate the distribution of electrode reactions in the electrode-electrolyte structure in order to determine the relationship between various parameters related to the power generation characteristics such as the characteristics of the fuel cell MEA, the fuel and oxidant supply methods.

  Here, as a method for investigating the distribution of the electrode reaction in the conventional electrode-electrolyte structure, for example, there is an electrode reaction distribution measuring system and an electrode reaction distribution measuring method disclosed in Patent Document 1.

  In this Patent Document 1, a method is shown in which one electrode side is divided into predetermined regions and a reaction current for each predetermined region is measured. Specifically, as shown in FIG. 11, an electrode-electrolyte structure 200 that is a fuel cell includes an electrolyte 201, a pair of electrodes 202 and 203 provided on both sides thereof, and a current collector provided on both sides thereof. It consists of bodies 204 and 205.

  One of the current collectors 204 is divided into a grid-like region by a partition 206 made of an insulator, and each of the divided current collectors 204 is connected to a lead wire 212 by soldering 211 and is illustrated in the figure. Not connected to voltage measuring device.

  The other current collector 205 is connected to the voltage measuring device via a copper plate 231. In addition, although not shown in Patent Document 1, the voltage measuring device is connected to the electrode-electrolyte structure of the fuel cell to be measured, and is used to control the total current or the inter-terminal voltage of the electrode-electrolyte structure. A load device, a current measuring device for measuring a reaction current in each of the plurality of partial regions of the electrode-electrolyte structure, and a resistance measurement for measuring an electrolyte resistance in each of the plurality of partial regions of the electrode-electrolyte structure The apparatus includes a device and a measurement control device that controls the electrode reaction distribution measurement system so as to simultaneously measure the reaction current and the electrolyte resistance in the same partial region among the plurality of partial regions.

  However, in the fuel cell current distribution measuring device and the fuel cell current distribution measuring method disclosed in Patent Document 1, the current collector 204 is divided by the partition 206, and the electromotive force obtained from the entire electrode 202 of the fuel cell. The partial electromotive force in is not accurately reproduced.

  That is, in the method of Patent Document 1, the power generation performance of a specific part of the fuel cell is measured using a special test sample and a current sensor. Therefore, the method of Patent Document 1 has a measurement error because the structure is different from the actual device. For this reason, actual products cannot be evaluated.

  In order to solve this problem, for example, in the fuel cell current distribution measuring apparatus 300 disclosed in Patent Document 2, an electromotive force distribution on the electrode surface of the fuel cell 310 is obtained as shown in FIGS. Therefore, a plurality of probe pins 304 that are in contact with the non-partition region on the outer surface of one fuel electrode side separator 303 in the pair of fuel electrodes 301 and air electrodes 302, and current measurement that measures the current flowing through each probe pin 304 Part 305.

  Thus, it is possible to provide a fuel cell current distribution measuring device and a fuel cell current distribution measuring method capable of accurately reproducing a partial electromotive force among electromotive forces obtained from the entire electrode of the fuel cell.

  Here, the measurement principle of the fuel cell current distribution measuring apparatus 300 will be described with reference to FIG. FIG. 14 is a portion A in FIG. 13 and is an enlarged view of the contact portion between the current probe (contact pin) and the fuel cell separator.

In FIG. 14, P ₁ and P ₂ indicate current measuring probes, R _S1 and R _S2 are equivalent resistances of the current measuring probes P ₁ and P ₂ , and R _C1 and R _C2 indicate current measuring probes P ₁ and P 2. ₂ and the contact resistance between the anode-side separator C.

The generated current passes from the assumed power generation zone to the anode side separator C, the current measurement probes P ₁ and P ₂ , the load, and the cathode separator to form a current circuit.
Since there is a separator resistance between the current measurement probes P ₁ and P ₂ , the generated currents I _G1 and I _G2 are redistributed depending on the resistance values of the equivalent resistances R _S1 , R _S2 , R _C1 , R _C2, and r _12. Is done.

FIG. 15 is an equivalent circuit of FIG. The relationship between the measured current and the generated current is expressed by (Expression 1) and (Expression 2). In (Expression 1) and (Expression 2), if the resistances R ₁ and R ₂ are the same value, the current of the equivalent resistance r ₁₂ becomes 0, and the measured current I _M1 = the generated current I _G1 and the measured current I _M2 = generated power The current I _G2 is obtained. That is, the generated current I _G1 can be displayed by the measured current I _M1 .

Thus, in the conventional fuel cell surface current measurement technique, measurement on the surface of the fuel cell separator using a current probe has become the mainstream.
JP 2003-77515 A (published March 14, 2003) JP 2005-302498 A (published October 27, 2005)

However, in the fuel cell current distribution measuring device and the fuel cell current distribution measuring method disclosed in the above-mentioned conventional patent document 2, generally, the contact resistances R _C1 and R _C2 change due to the measurement. The current redistribution due to the contact resistance R _C1 · R _C2 between the probe pin 304 and the surface of the fuel electrode side separator 303 due to. As a result, the measured current I _M1 and the generated current I _G1 do not match, and there is a problem that an error occurs between the measured current I _M1 and the generated current.

That is, since the probe pin 304 by the current probe is brought into contact with the surface of the power generation device, a measurement error due to the uncertainty of the contact resistances R _C1 and R _C2 occurs. This is because the contact resistance changes with each measurement due to the influence of each element such as the shape of the tip of the current probe, the usage status, the separator surface status, and the pressure applied to the current probe. This is because it is difficult to reduce measurement errors.

  The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to avoid the influence of contact resistance and accurately determine the partial electromotive force in the electromotive force obtained from the entire electrode of the fuel cell. An object of the present invention is to provide a reproducible fuel cell current distribution measuring device, laminated fuel cell current distribution measuring device, and fuel cell current distribution measuring method.

In order to solve the above problems, a fuel cell current distribution measuring device of the present invention has an electrolyte and a fuel electrode side electrode in a fuel cell having a pair of fuel electrode and air electrode provided on both sides of the electrolyte. In a fuel cell current distribution measuring apparatus for measuring a fuel cell current distribution by bringing a plurality of probes into contact with a corresponding surface, the probe includes a current probe for measuring current, and an electrode on the fuel electrode side in each of the current probes . A voltage probe for measuring the voltage by contacting the vicinity of the contact position to the equivalent surface, and from the fuel electrode of the fuel cell to the air electrode via the electrode equivalent surface on the fuel electrode side and the current probe. current measuring means for measuring the current flowing in the closed circuit, a voltage measuring means for measuring the voltage of the contact position of the electrode corresponding surface of the fuel electrode side in the voltage probe, the electrocoating A measured current measured by the measuring means, from the measured measurement voltage by said voltage measuring means and a generated current calculating means for determining the power generation current of the fuel cell is provided, the generated current calculating unit, the A measurement current of one point to the electrode equivalent surface on the fuel electrode side by the current probe, a measurement voltage of the voltage probe at a position near one point to the electrode equivalent surface on the fuel electrode side by the current probe, and its surroundings The power generation current of the fuel cell is obtained from the measured voltages of the four voltage probes at the front, rear, left and right .

In addition, in order to solve the above problems, the fuel cell current distribution measuring method of the present invention is a fuel electrode side in a fuel cell having an electrolyte and a pair of fuel electrodes and air electrodes provided on both sides of the electrolyte. In the fuel cell current distribution measuring method for measuring the fuel cell current distribution by bringing a plurality of probes into contact with the electrode equivalent surface, the probe includes a current probe for measuring current, and a fuel electrode side in each of the current probes A voltage probe for measuring the voltage in contact with the vicinity of the contact position with the electrode equivalent surface of the fuel cell, and the air electrode from the fuel electrode of the fuel cell via the electrode equivalent surface on the fuel electrode side and the current probe a current measuring step of measuring the current flowing through the closed circuit to a voltage measuring step of measuring the voltage of the contact position of the electrode corresponding surface of the fuel electrode side in the voltage probe, A measured current measured by the serial current measuring step, from the measurement voltage and the measurement by the voltage measuring step, and a generated current calculating step of obtaining the power generation current of the fuel cell, in the power generation current calculating step, for the current The measurement current of one point to the electrode equivalent surface on the fuel electrode side by the probe, the measurement voltage of the voltage probe near the one point to the electrode equivalent surface on the fuel electrode side by the current probe, and the surroundings It is characterized in that the generated current of the fuel cell is obtained from the measured voltages of the four voltage probes on the left and right .

  As a result, the measurement error due to contact resistance is reduced compared to measuring the current on the surface of the fuel cell only with the current measuring means, and the fuel cell internal generated current can be measured on the surface of the fuel cell. That is, an accurate measured current value closer to the actual generated current can be obtained. Further, by directly sucking up the current by each measurement probe, the power loss on the electrode due to the measurement jig can be reduced. In addition, for a fuel cell with a large current density and large area, a current redistribution on the measurement surface may occur due to the resistance of a current probe or the like, for example, the resistance of a fuel cell separator and the contact resistance between the current probe and the separator. Therefore, the difference between the measured current value at each current probe and the generated current at the corresponding measurement point, or the contact resistance value changes with each measurement, so the measurement must be corrected during the measurement. The influence of the fuel cell current voltage (IV) characteristic by the system can be reduced.

  Accordingly, there are provided a fuel cell current distribution measuring device and a fuel cell current distribution measuring method capable of accurately reproducing a partial electromotive force in an electromotive force obtained from the entire electrode of the fuel cell while avoiding the influence of contact resistance. be able to.

Further, in the present invention, the generated current calculation means includes one measurement current to the electrode equivalent surface on the fuel electrode side by the current probe and one point to the electrode equivalent surface on the fuel electrode side by the current probe. The power generation current of the fuel cell is obtained from the measurement voltage of the voltage probe in the vicinity of, and the measurement voltages of the four voltage probes around the front, rear, left and right.

  Thereby, a measurement result is calculated using an equivalent model, an actual generated current value can be output, and an actual power generation amount and a measured value can be matched more accurately. In addition, the amount of power generated by the fuel cell can be known efficiently, and measurement can be performed more accurately at a low cost. Furthermore, the influence of measurement circuit errors can be reduced by a method of calculating the generated current using one unit of measurement signal, that is, a one-point current signal and a five-point voltage signal.

  In the fuel cell current distribution measuring apparatus of the present invention, the current measuring means preferably includes a current sensor for measuring a current flowing in the closed circuit.

  Thereby, the current from the current probe can be measured easily and accurately.

  In the fuel cell current distribution measuring apparatus of the present invention, the current sensor preferably includes a resistor provided in a closed circuit and a both-end voltage measuring means for measuring a voltage applied to both ends of the resistor. .

  Thus, specifically, a current sensor with an easy configuration can be obtained.

In order to solve the above-described problems, a laminated fuel cell current distribution measuring apparatus according to the present invention includes a fuel cell that includes an electrolyte and a pair of fuel electrodes and air electrodes provided on both sides of the electrolyte. in the stacked fuel cell current distribution measuring apparatus for measuring the fuel cell current distribution of the two or more integer) laminated formed by stacking fuel cells, a K stage positioned below the first K stages (K ≦ N) a measuring means which is placed on the electrode corresponding surface of the fuel electrode side in the fuel cell of the K-stage to measure the summed generating current distribution generation current of the fuel cell-to N-th stage, the measuring means A current collector plate provided on the upper side and fuel cells from the (K-1) th stage to the first stage stacked on the current collector board are provided, and the measuring means is for measuring current. Equivalent to the electrode on the fuel electrode side in the K-th stage fuel cell To be contacted, and a plurality of which are connected to the collector plate and the current probe, a plurality of for measuring a voltage in contact with the vicinity contact position of the electrode corresponding surface of the fuel electrode side of each current probe and a voltage probe, addition, the electrode corresponding surface from the fuel electrode of the fuel electrode side of the fuel cell of the K-stage, the air electrode of the fuel cell of the first N-stage via a current probe and collector plates Current measuring means for measuring the current flowing in the closed circuit to the electrode, voltage measuring means for measuring the voltage at the contact position of the voltage probe to the electrode equivalent surface on the fuel electrode side, and the current measuring means. a measured current was, from the measured measurement voltage by said voltage measuring means and and a generator current calculating means for calculating a generation current of the fuel cell, the generation current calculation means in the current probe The measurement current of one point to the electrode equivalent surface on the fuel electrode side, the measurement voltage of the voltage probe in the vicinity of one point to the electrode equivalent surface on the fuel electrode side by the current probe, and the front, rear, left and right around it The current generated by the fuel cell is obtained from the measured voltages of the four voltage probes .

  As a result, in the stacked fuel cell current distribution measuring device, the generated current distribution obtained by summing the generated currents of the fuel cells from the Kth stage to the Nth stage located below the Kth stage (K ≦ N) is measured. can do.

  Therefore, it is possible to provide a stacked fuel cell current distribution measuring apparatus that can accurately reproduce a partial electromotive force in an electromotive force obtained from the entire electrode of the fuel cell while avoiding the influence of contact resistance.

In order to solve the above-described problems, a laminated fuel cell current distribution measuring apparatus according to the present invention includes a fuel cell that includes an electrolyte and a pair of fuel electrodes and air electrodes provided on both sides of the electrolyte. Is a stacked fuel cell current distribution measuring device that measures the fuel cell current distribution of stacked fuel cells that are stacked by two or more, and measures the generated current distribution of the Kth (K ≦ N) fuel cells. Preferably, the first measuring means placed on the electrode equivalent surface on the fuel electrode side above the Kth fuel cell, and the electrode equivalent surface on the air electrode side below the Kth fuel cell. And a first measuring means for measuring a current to measure a generated current from the Kth stage to the lower Nth stage. the electrode corresponding surface of the fuel electrode side in the fuel cell K stages Is touch and, a plurality of first current probe connected to the electrode corresponding surface of the air electrode side in the K-1 stage of the fuel cell, the fuel electrode side in each of the first current probe electrode Each of the first voltage probes for measuring a voltage in contact with the vicinity of the contact position to the corresponding surface, the electrode corresponding surface on the fuel electrode side from the fuel electrode of the K-th stage fuel cell, and First current measuring means for measuring a current flowing in a closed circuit to the air electrode of the N-th stage fuel cell via the first current probe, and an electrode on the fuel electrode side in the first voltage probe From the first voltage measuring means for measuring the voltage at the contact position to the equivalent surface, the measured current measured by the first current measuring means, and the measured voltage measured by the first voltage measuring means, first generating electric seeking generation current of the fuel cell And a calculation unit, said first generating current calculation means, the measurement current point to the electrode corresponding surface of the fuel electrode side of the first current probe, a fuel electrode according to the first current probe The generated voltage of the fuel cell is determined by the measured voltage of the first voltage probe in the vicinity of one point on the electrode equivalent surface on the side and the measured voltages of the four first voltage probes around the front, rear, left and right around it. And the second measuring means measures the generated current from the (K + 1) th stage to the lower Nth stage, so that the air electrode side in the Kth stage fuel cell for measuring current is measured. A plurality of second current probes connected to the electrode equivalent surface on the fuel electrode side in the (K + 1) th stage fuel cell, and the air electrode in each second current probe Contact near the electrode equivalent surface on the side Each second voltage probe for measuring a voltage, and further, each contact point to the electrode equivalent surface on the air electrode side in the second current probe, and the first current probe The contact points with the electrode-corresponding surface on the fuel electrode side of the probe are at the same position in the vertical direction, and the electrode-corresponding surface on the lower air electrode side and the second surface in the K-th stage fuel cell. Second current measuring means for measuring the current flowing in the closed circuit to the air electrode of the N-th stage fuel cell through the current probe, and the electrode on the air electrode side in the second voltage probe From the second voltage measuring means for measuring the voltage at the position of contact with the surface, the measured current measured by the second current measuring means, and the measured voltage measured by the second voltage measuring means, a fuel is obtained. second generator for obtaining the power generation current of the battery A flow calculation unit, according to the second generation current calculation means, the measurement current point to the electrode corresponding face of the air electrode side by the second current probe, said second current probe A fuel cell according to the measurement voltage of the second voltage probe in the vicinity of one point on the electrode equivalent surface on the air electrode side and the measurement voltage of the four second voltage probes around the front, rear, right and left around the second voltage probe together with obtaining the generated current, the difference between the current generated at each contact point of the plane to the same position in the vertical direction between the first measuring means and second measuring means, the fuel cell of the K-stage It is characterized by measuring the generated current distribution.

  According to the above invention, the K-th stage fuel cell is sandwiched between the first measuring means and the second measuring means. Therefore, at this time, the first measuring means and the second measuring means have opposite current polarities.

As a result, the generated current distribution of the K-th stage fuel cell is measured by the difference between the first measuring means and the second measuring means in the vertical direction and the generated currents at the contact points at the same position in the plane. can do. That is, the difference in current between adjacent fuel cell single cells can be obtained. Therefore, even when it is desired to know the power generation amount of each stacked fuel cell in the stacked fuel cell, by checking the difference between the surface current of any fuel cell and the adjacent fuel cell, The amount of power generated by the battery can be grasped.

  As a result, it is possible to provide a stacked fuel cell current distribution measuring apparatus that can accurately reproduce a partial electromotive force of electromotive forces obtained from the entire electrodes of the fuel cell while avoiding the influence of contact resistance.

  As described above, the fuel cell current distribution measuring device, the laminated fuel cell current distribution measuring device, and the fuel cell current distribution measuring method of the present invention are measured by the current measuring means and the voltage measuring means. The generated current of the fuel cell is obtained from the measured voltage.

  Therefore, a fuel cell current distribution measuring device, a laminated fuel cell current distribution measuring device, which can accurately reproduce a partial electromotive force among electromotive forces obtained from the entire electrodes of the fuel cell, avoiding the influence of contact resistance, and There is an effect of providing a fuel cell current distribution measuring method.

[Embodiment 1]
An embodiment of the present invention will be described below with reference to FIGS. In the present embodiment, for example, measurement of electromotive force distribution on the electrode surface of a hydrogen fuel cell has been described. However, the present embodiment is not limited to this and can be applied to a direct methanol battery (DMFC) or other fuel cells.

  First, a configuration of a fuel cell that is a target of fuel cell current distribution measurement in the fuel cell current distribution measuring apparatus of the present embodiment will be described with reference to FIG.

  2A, the fuel cell 10 includes an electrolyte 1 serving as an ionic conductor, a fuel electrode 2 as a pair of electrodes, a fuel electrode-side separator 3, and an air electrode 4 as a pair of electrodes. The air electrode side separator 5 and a current collector plate (not shown) which is an electrode for taking out the air electrode 4 from the outside.

  Specifically, as shown in FIG. 2B, the fuel electrode 2 includes, for example, a carbon electrode 2a and a catalyst 2b made of platinum (Pt). The air electrode 4 has the same configuration.

The fuel electrode side separator 3 and the air electrode side separator 5 have vertical stripe grooves and horizontal stripe grooves, respectively, as shown in FIG. For example, fuel gas such as hydrogen (H ₂ ) gas is supplied into the vertical stripe grooves of the fuel electrode side separator 3, while An oxidant gas such as oxygen (O ₂ ) or air is supplied.

  A measurement jig for measuring the fuel cell 10 will be described with reference to FIGS.

  In the present embodiment, as shown in FIG. 3, a plurality of electrical joining members and a measuring probe 25 as a contact pin are provided on the outer surface of the fuel electrode side separator 3 as an electrode equivalent surface. 3 is provided so that it can contact 3. The measurement probe 25 includes a current probe 22 for current measurement and a voltage probe 23 for voltage measurement provided in the vicinity of the current probe 22.

A fuel gas supply path 78 for supplying a fuel gas such as the hydrogen (H ₂ ) gas is formed in the upper clamping plate 76. In the present embodiment, the fuel electrode side separator 3 is not provided with a partition by a conventional partition or the like, and as a result, the measurement probe 25 is provided in a non-compartment region on the outer surface of the fuel electrode side separator 3. Will be touched.

  In the present embodiment, the measurement probe 25 is provided so as to penetrate through the through holes formed in the upper clamping plate 76 and the probe jig plate 77 in the fuel cell current distribution measuring apparatus 20. Further, the measurement probe 25 can come into contact with the fuel electrode side separator 3 in a pressed state when the measurement probe 25 contacts the fuel electrode side separator 3 by a spring (not shown).

  Furthermore, as shown in FIG. 4, 7 × 7 = 49 measuring probes 25 according to the present embodiment are provided at a pitch of 6 mm, for example. However, the present invention is not necessarily limited thereto, and may be, for example, a 25 mm pitch, a 45 mm pitch, or the like. That is, in the present embodiment, if the measurement probe 25 is brought into contact with the fuel electrode side separator 3 at a pitch of 6 mm, the fuel electrode side separator 3 can be sufficiently spaced between adjacent regions without being partitioned by an insulator. Since it was verified by experiments that a difference in current can be found, the fuel electrode side separator 3 is not partitioned by an insulator.

  A current collector plate 6 made of copper (Cu) that contacts the air electrode side separator 5 is provided on the outer surface of the air electrode side separator 5, and this current collector plate 6 is provided outside the air electrode 4. It is an extraction electrode.

  The fuel cell 10 is placed on the lower fastening plate 71 via a silicon sheet 72 and a rubber heater 73. That is, in the present embodiment, the temperature of the fuel cell 10 can be raised from the normal temperature by the rubber heater 73.

Further, an air supply path 74 for supplying an oxidant gas such as oxygen (O ₂ ) or air is formed inside the lower clamping plate 71.

  An overall outline of the fuel cell current distribution measuring apparatus 50 for measuring the current distribution on the surface of the fuel electrode side separator 3 in the fuel cell 10 will be described with reference to FIG.

As shown in the figure, the fuel cell current distribution measuring device 20 is provided with a fuel tank 11 for storing a fuel gas such as hydrogen (H ₂ ) gas in order to operate the fuel cell 10. The liquid feed pump supplies the fuel cell 10 through the liquid flow meter 12. Further, the oxidant gas is supplied to the fuel cell 10 through the gas flow meter 15 from the oxidant cylinder 13 that stores oxidant gas such as oxygen (O ₂ ) or air.

  Further, a cathode drain tank 16 for storing cathode (air electrode side) drainage from the fuel cell 10 and an anode drain tank (not shown) for storing anode (fuel electrode side) drainage from the fuel cell 10 are provided. Yes.

  Further, the current distribution and the temperature distribution on the surface of the fuel electrode side separator 3 of the fuel cell 10 are detected by the sensor unit 32, and the data is input to the personal computer 42. Furthermore, in the measurement of the current distribution on the surface of the fuel electrode side separator 3 of the fuel cell 10, an electronic load device 33 that loads a resistor for obtaining an appropriate current value is connected.

  The sensor unit 32 includes a measurement probe 25 for detecting current and the thermocouple 37 for measuring temperature. The temperature detected by the thermocouple 37 is detected by a thermometer 45.

On the other hand, the electronic load device 33 has a plurality of resistors, depending on the selection of one from among them, so that retrieve the appropriate current value when the current signal collection in current signal acquisition module 44 It has become. This resistance can be selected by the personal computer 42. In addition, the electronic load device 33 according to the present embodiment has a function capable of a constant current load mode, a constant voltage load mode, and the like, and can be used for a current-voltage characteristic test in these modes and other load tests. Thus, for example, a maximum load of 200 W, 40 A or less, and a voltage of 0 to 200 V can be applied.

In addition, as shown in FIG. 5, the data collection processing device 43 is input with data such as flow rate setting data, flow rate measurement data, and flow rate data of the gas flow meter 15, and the generated current. A measurement current resistance correction calculation unit 46 is provided as calculation means .

  The configuration of the fuel cell current distribution measuring apparatus according to the present embodiment for measuring the current distribution on the surface of the fuel electrode side separator 3 in the fuel cell 10 will be described with reference to FIGS.

  FIG. 1A is an upper view of a separator on which a voltage probe 23 and a current probe 22 are arranged. FIG. 1B is an enlarged view of a contact portion between the current probe 22 that is a contact pin and the fuel cell separator. FIG.

  As shown in FIG. 1B, the fuel cell current distribution measuring apparatus 20 has a matrix of measuring probes 25 each comprising a voltage probe 23 and a current probe 22 on the surface of the fuel electrode side separator 3 of the fuel cell 10. The measurement probe 25 is connected to one end of the current sensor 24. Furthermore, the terminal of the current sensor 24 that is not connected to the measurement probe 25 is connected to an external electronic load. Thus, the fuel cell current distribution measuring device 20 is configured as an electric closed circuit.

  Further, the measurement probe 25 is connected to a current measuring means including a current sensor 24 and a voltmeter (not shown) that measures the voltage across the current sensor 24.

  In the present embodiment, a shunt resistor is used as the current sensor 24. As a result, the current of the measurement probe 25 is measured.

  Further, the voltage probe 23 is attached in the vicinity of the current probe 22, and the fuel electrode side separator 3 is brought into contact with the current probe 22 at the same time. This makes it possible to take out voltage signals at each point.

  Next, a measurement method in the fuel cell current distribution measuring apparatus 20 will be described. First, a method for extracting a signal in the fuel cell current distribution measuring apparatus 20 will be described, and then an equivalent model of the measurement circuit and a measurement current correction principle will be described.

[How to extract signals]
First, as shown in FIG. 1B, a method for extracting a signal in the fuel cell current distribution measuring device 20 is as follows. In this embodiment, the measurement probe 25 is brought into contact with the surface of the fuel electrode side separator 3 to thereby separate the fuel electrode side separator. 3, the current of the fuel electrode side separator 3 is measured by the current sensor 24 connected to the measurement probe 25 via the measurement probe 25.

  The voltage probe 23 is attached in the vicinity of the current probe 22 and is brought into contact with the fuel electrode side separator 3 simultaneously with the current probe 22 to take out voltage signals at each point.

[Equivalent model of measurement circuit]
Next, an equivalent model of the measurement circuit will be described based on FIG.

  FIG. 6 shows an equivalent model of the fuel cell current distribution measuring apparatus 20 shown in FIG.

  First, it is assumed that the generated current in the upper part of the fuel cell current distribution measuring device 20 is concentrated at the position of the measurement probe 25. Further, the generated current at each assumed point is assumed to be a current source.

  Considering the resistance of the fuel electrode side separator 3, the resistance of the fuel electrode side separator 3 exists between the measurement probes 25. Further, the resistance between the measurement probe 25 and the current sensor 24 and the resistance between the measurement probe 25 and the fuel electrode side separator 3 are considered.

  FIG. 3 shows an equivalent model of contact resistance in the single measurement probe 25 and the current sensor 24 by considering the resistance.

  Here, the symbols in FIG. 6 and FIGS. 1A and 1B are compared as follows.

M, N ← → 0
M, N-1 ← → 1
M, N + 1 ← → 3
M-1, N ← → 2
M + 1, N ← → 4
(K) ← → −δ / ρ
Thereby, the correction calculation formula of the generated current of each point with respect to the measurement surface of FIG.

It becomes.

  Here, since only the current signal at the measurement point and the surrounding voltage signal are used in the voltage correction method model of the present embodiment in FIG. 6, the voltage in the measurement probe 25 is theoretically arbitrary. The value does not affect the measurement. Therefore, the jig structure of the measurement part such as current and voltage can be simplified.

[Embodiment 2]
The following will describe another embodiment of the present invention with reference to FIGS. Configurations other than those described in the present embodiment are the same as those in the first embodiment. For convenience of explanation, members having the same functions as those shown in the drawings of the first embodiment are given the same reference numerals, and explanation thereof is omitted.

  FIG. 7 shows an example of the structure of the fuel cell stack. The fuel cell stack of the present embodiment is configured by connecting the single cells of the first embodiment in series.

  FIG. 8B shows a specific configuration of the measurement unit 30. The measuring unit 30 includes a current probe 22, a voltage probe 23, a current sensor 24, a current collector plate 29, and the like provided on the surface of the fuel electrode side separator 3 of the fuel cell 21.

  FIG. 8A shows a specific configuration of the stacked fuel cell measuring apparatus. As shown in the figure, the measurement unit 30 is formed on the fuel cell 21 and the fuel cell 21 and the measurement unit 30 are alternately formed to form a stacked fuel cell measurement device between the stacked fuel cells. Is done.

Further, by calculating from the current and voltage measured from the voltage probe 23, current probe 22, and current sensor 24 using the equation of the equivalent model in FIG. Can be sought.
[Elimination of effects of power generation current of other fuel cells on measurement results]
Next, the influence of measurement that each cell has on other cells will be described with reference to FIG.

  In the measurement examples of FIGS. 8A and 8B, the measured current value is not only the generated current of the specified cell but also the generated current of all the cells under the specified cell. Therefore, in order to show the power generation status of only the corresponding cell, the current in this part must be extracted.

  FIG. 9 is an example of measurement of the generated current surface distribution of a single fuel cell in a stacked fuel cell. The generated current surface distribution measuring unit 60 includes two measuring units 64.

  The measuring unit 61 measures the sum of the generated current of the fuel cell N and the generated current of the fuel cell N + 1..., And the measuring unit 62 sets the generated current of the cell N + 1. Current flows in. Thereby, the difference of each point current of the measurement unit 61 and the measurement unit 62 is calculated | required, and the electric power generation current of the fuel cell N is displayed. Here, the polarity of each point current of the measurement unit 61 and the polarity of each point current of the measurement unit 62 are set to be opposite.

  In order to eliminate the current conduction error between the cells, the current drawing probe 63 is used in the measurement unit 61 and the measurement unit 62 in FIG. 9 instead of the current collector plate 29 in FIGS. 8 (a) and 8 (b). It has been broken.

  The structure of the measurement unit 64 is a structure suitable for the measurement method according to the present embodiment because the polarity of the voltage of the measurement unit 61 and the measurement unit 62 is reversed in the opposite direction.

  As described above, the fuel cell current measuring device of the present embodiment measures the current value in the direction along the separator with the voltage probe 23 while measuring the current with the current probe 22. That is, the current value on the separator surface is measured. Further, by utilizing the basic laws of the electric circuit, the information extracted by each current probe 22 and the voltage probe 23 is calculated and the voltage correction calculation is performed to output the distribution of the generated current inside the fuel cell. it can.

  Further, the relationship between the characteristics of the power generation device such as the material, shape and structure and the power generation performance of the power generation device can be evaluated by the current distribution on the surface of the fuel cell.

  The present invention can be applied to the measurement of electromotive force distribution on the electrode surface of a hydrogen fuel cell, a direct methanol cell (DMFC) or other fuel cells.

(A) (b) is a figure which shows the structure of the fuel cell current distribution measuring apparatus of this embodiment. FIG. 2A is an exploded perspective view showing the configuration of the fuel cell shown in FIG. 1, and FIG. 2B is a perspective view showing the details of the configuration of the fuel electrode of the fuel cell shown in FIG. It is sectional drawing which shows the fuel cell and probe of the fuel cell current distribution measuring apparatus shown in FIG. It is a top view which shows the probe and lead wire of the fuel cell current distribution measuring apparatus shown in FIG. It is a block diagram which shows the whole structure of the said fuel cell current distribution measuring apparatus. It is a schematic diagram which shows the equivalent model of the said fuel cell current distribution measuring apparatus. It is a perspective view which shows the structure of the fuel cell of the 2nd Embodiment of this invention. (A) is sectional drawing which showed the cross section of the fuel cell current distribution measuring system which applied the fuel cell current distribution measuring apparatus shown in the said FIG. 7 to a stack, (b) is only a single cell of (a). It is sectional drawing of a fuel cell current distribution measuring system. FIG. 9 is a cross-sectional view showing an example of measurement of a generated current surface distribution of only a designated cell in a stack of the fuel cell current distribution measuring apparatus shown in FIG. It is a schematic diagram which shows the basic composition of the conventional fuel cell. It is sectional drawing which shows the conventional fuel cell current distribution measuring apparatus. It is a schematic diagram which shows the conventional fuel cell current distribution measuring apparatus. It is sectional drawing which shows the fuel cell and probe of the conventional fuel cell current distribution measuring apparatus. It is sectional drawing which shows the contact part of the current probe and fuel cell separator in the conventional fuel cell current distribution measuring apparatus shown in FIG. It is a circuit diagram which shows the equivalent circuit of the contact part of the current probe and fuel cell separator which are shown in the said FIG.

DESCRIPTION OF SYMBOLS 1 Electrolyte 2 Fuel electrode 2a Carbon electrode 2b Catalyst 3 Fuel electrode side separator 4 Air electrode 5 Air electrode side separator 10 Fuel cell 11 Fuel tank 12 Liquid flow meter 13 Oxidant cylinder 15 Gas flow meter 16 Cathode drainage tank 20 Fuel cell current Distribution measuring device 21 Fuel cell 22 Current probe 23 Voltage probe (voltage measuring means)
24 Current sensor 25 Measuring probe 29 Current collecting plate (current collecting means)
30 Measurement Unit 32 Sensor Unit 33 Electronic Load Device 46 Measurement Current Resistance Correction Calculation Unit ( Generation Current Calculation Means )
61 Measurement Unit 62 Measurement Unit 63 Current Extraction Probe 64 Measurement Unit 60 Current Generation Surface Distribution Measurement Unit 71 Lower Tightening Plate 72 Silicon Sheet 73 Rubber Heater 74 Air Supply Path 76 Upper Tightening Plate 77 Probe Jig Plate 78 Fuel Gas Supply Path

Claims (6)

A fuel cell for measuring a fuel cell current distribution by bringing a plurality of probes into contact with an electrode equivalent surface on the fuel electrode side in a fuel cell having an electrolyte and a pair of fuel electrode and air electrode provided on both sides of the electrolyte. In the current distribution measuring device,
The probe comprises a current probe for measuring current, and a voltage probe for measuring the voltage in contact with the vicinity of the contact position to the electrode equivalent surface on the fuel electrode side in each of the current probes,
Current measuring means for measuring a current flowing in a closed circuit from the fuel electrode of the fuel cell to the electrode corresponding surface on the fuel electrode side and the air electrode via a current probe;
Voltage measuring means for measuring a voltage at a contact position on the electrode equivalent surface on the fuel electrode side in the voltage probe;
A power generation current calculating means for determining a power generation current of the fuel cell from the measurement current measured by the current measurement means and the measurement voltage measured by the voltage measurement means ; and
The generated current calculation means includes:
One point of measurement current to the electrode equivalent surface on the fuel electrode side by the current probe,
Power generation of the fuel cell by the measurement voltage of the voltage probe in the vicinity of one point to the electrode equivalent surface on the fuel electrode side by the current probe and the measurement voltage of the four voltage probes around the front, rear, left and right around it fuel cell current distribution measuring apparatus and obtaining the current.   2. The fuel cell current distribution measuring device according to claim 1, wherein the current measuring means includes a current sensor for measuring a current flowing in the closed circuit.   3. The fuel cell current distribution measurement according to claim 2, wherein the current sensor comprises a resistor provided in a closed circuit and a both-end voltage measuring means for measuring a voltage applied to both ends of the resistor. apparatus. Fuel cell current distribution of a stacked fuel cell formed by stacking N (N is an integer of 2 or more) fuel cells having an electrolyte and a pair of fuel electrodes and air electrodes provided on both sides of the electrolyte. In the laminated fuel cell current distribution measuring device for measuring
Fuel electrode in the K-th stage fuel cell to measure the generated current distribution of the total generated currents of the fuel cells from the K-th stage to the N-th stage located below the K-th stage (K ≦ N) Measuring means placed on the electrode equivalent surface side ,
A current collector provided on the upper side of the measuring means ;
Fuel cells from the (K-1) th stage to the first stage stacked on the current collector plate are provided,
The measuring means is
A plurality of current probes that are in contact with the electrode-corresponding surface on the fuel electrode side in the K-th stage fuel cell for measuring current and connected to the current collector plate, and the fuel electrode side in each current probe A plurality of voltage probes for measuring the voltage in contact with the vicinity of the contact position to the electrode equivalent surface,
Furthermore, the current flowing in the closed circuit from the fuel electrode of the K-th stage fuel cell to the air electrode side of the fuel electrode side , the current probe and the current collector plate through the current electrode. Current measuring means for measuring,
Voltage measuring means for measuring a voltage at a contact position on the electrode equivalent surface on the fuel electrode side in the voltage probe;
A measured current measured by the current measuring means, from the measured measurement voltage by said voltage measuring means and and a generator current calculating means for calculating a generation current of the fuel cell,
The generated current calculation means includes:
One point of measurement current to the electrode equivalent surface on the fuel electrode side by the current probe,
The fuel cell is generated by the measured voltage of the voltage probe at a position near one point on the electrode equivalent surface on the fuel electrode side by the current probe and the measured voltages of the four voltage probes around the front, rear, left and right. An apparatus for measuring current distribution of a laminated fuel cell, characterized by obtaining a current. Fuel cell current distribution of a stacked fuel cell formed by stacking N (N is an integer of 2 or more) fuel cells having an electrolyte and a pair of fuel electrodes and air electrodes provided on both sides of the electrolyte. In the laminated fuel cell current distribution measuring device for measuring
First measuring means mounted on the electrode equivalent surface on the fuel electrode side above the K-th stage fuel cell to measure the generated current distribution of the K-th stage (K ≦ N) fuel cell; A second measuring means that contacts the electrode equivalent surface on the air electrode side below the K-th stage fuel cell, and
The first measuring means measures the generated current from the Kth stage to the lower Nth stage,
In contact with the electrodes corresponding surface of the fuel electrode side in the first K stages of the fuel cell for measuring the current, and connected to the electrode corresponding surface of the air electrode side in the K-1 stage of the fuel cell more a first current probe, and the first voltage probe for measuring the voltage in contact with the vicinity contact position of the electrode corresponding surface of the fuel electrode side in each of the first current probe Yu And
Measure the current flowing in the closed circuit from the fuel electrode of the Kth stage fuel cell to the electrode equivalent surface on the fuel electrode side and the air electrode of the Nth stage fuel cell via the first current probe. First current measuring means;
First voltage measuring means for measuring a voltage at a contact position on the electrode equivalent surface on the fuel electrode side in the first voltage probe;
A first generated current calculating means for determining a generated current of the fuel cell from the measured current measured by the first current measuring means and the measured voltage measured by the first voltage measuring means;
The first generated current calculation means includes:
A measurement current at one point to the electrode equivalent surface on the fuel electrode side by the first current probe;
The measurement voltage of the first voltage probe in the vicinity of one point on the electrode equivalent surface on the fuel electrode side by the first current probe, and the four first voltage probes at the front, rear, left and right around it . Based on the measured voltage, the generated current of the fuel cell is obtained,
The second measuring means measures the generated current from the (K + 1) th stage to the lower Nth stage,
In contact with the electrodes corresponding surface of the air electrode side in the fuel cell of the first K stages for measuring the current, and a plurality of which are connected to the electrodes corresponding surface of the fuel electrode side in the K + 1-stage fuel cell the and second current probe, and a respective second voltage probe for measuring the voltage in contact with the vicinity contact position of the electrode corresponding face of the air electrode side of each of the second current probe, Further, each contact point to the electrode equivalent surface on the air electrode side in the second current probe and each contact point to the electrode equivalent surface on the fuel electrode side in the first current probe are in the vertical direction. In the same plane,
A current flowing in a closed circuit to the air electrode on the lower air electrode side and the air electrode of the Nth fuel cell through the second current probe is measured in the Kth fuel cell. A second current measuring means;
Second voltage measuring means for measuring a voltage at a position of contact with the electrode equivalent surface on the air electrode side in the second voltage probe;
A second generated current calculating means for determining a generated current of the fuel cell from the measured current measured by the second current measuring means and the measured voltage measured by the second voltage measuring means;
The second generated current calculation means includes:
One point of measurement current to the electrode equivalent surface on the air electrode side by the second current probe;
Measurement voltage of the second voltage probe in the vicinity of one point to the electrode equivalent surface on the air electrode side by the second current probe, and the four second voltage probes on the front, rear, left and right around the second voltage probe With the measured voltage of
Measure the generated current distribution of the K-th stage fuel cell according to the difference between the first measuring means and the second measuring means in the vertical direction and the generated current at each contact point in the same plane in the vertical direction. A fuel cell current distribution measuring apparatus characterized by the above. A fuel cell for measuring a fuel cell current distribution by bringing a plurality of probes into contact with an electrode equivalent surface on the fuel electrode side in a fuel cell having an electrolyte and a pair of fuel electrode and air electrode provided on both sides of the electrolyte. In the current distribution measurement method,
The probe comprises a current probe for measuring current, and a voltage probe for measuring the voltage in contact with the vicinity of the contact position to the electrode equivalent surface on the fuel electrode side in each of the current probes,
A current measuring step of measuring a current flowing in a closed circuit from the fuel electrode of the fuel cell to the electrode corresponding surface on the fuel electrode side and the air electrode via the current probe;
A voltage measuring step for measuring a voltage at a contact position on the electrode equivalent surface on the fuel electrode side in the voltage probe;
A generated current calculation step for obtaining a generated current of the fuel cell from the measured current measured by the current measuring step and the measured voltage measured by the voltage measuring step ;
In the generation current calculation step,
One point of measurement current to the electrode equivalent surface on the fuel electrode side by the current probe,
Power generation of the fuel cell by the measurement voltage of the voltage probe in the vicinity of one point to the electrode equivalent surface on the fuel electrode side by the current probe and the measurement voltage of the four voltage probes around the front, rear, left and right around it fuel cell current distribution measuring method and obtains the current.

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