Fuel cell vehicle

Abstract

The present invention provides a fuel cell vehicle which is provided with: a control device that is capable of calculating the water content distribution within a fuel cell by detecting the pressure distribution in the in-plane direction without becoming an excess resistance to the power generating operation of the fuel cell; and a fuel cell stack. This fuel cell vehicle comprises: a fuel cell stack wherein a plurality of fuel cells are stacked and a pressure distribution measurement plate, which is capable of measuring the in-plane pressure distribution, is interposed between an end plate and a collector plate; and a control device that is capable of calculating the water content distribution of a fuel cell in the in-plane direction on the basis of the in-plane pressure distribution.

Description

fuel cell car

[0001] The present disclosure relates to fuel cell vehicles.

[0002] Transportation is essential in modern society, and various vehicles, including automobiles, travel the roads in our daily lives. Among these, fuel cells, which have a relatively low environmental impact, are attracting attention as a new power source for supplying driving force to vehicles.

[0003] In such fuel cells, fuel gas (hydrogen) is supplied to one electrode (fuel electrode) and oxidant gas (oxygen) is supplied to the other electrode (air electrode), and electrical energy is generated through a chemical reaction between these. It is known that the resistance of the electrolyte membrane, which constitutes part of the fuel cell, decreases as the water content increases, while the resistance increases as the membrane dries and the water content decreases. Excessive water content in such an electrolyte membrane results in distortion due to the expansion of the electrolyte membrane, which causes a decrease in the performance and durability of the fuel cell. Therefore, in order to continuously obtain appropriate electrical energy (generated power) from the fuel cell, it is important to manage the water content within the fuel cell stack installed in the vehicle.

[0004] For example, Patent Document 1 discloses a fuel cell stack in which dummy cells are arranged at both ends of the stacking direction of unit cells. The dummy cells in Patent Document 1 include a sheet-like pressure distribution detection means for measuring the stack load distribution of the unit cells, and both sides of this pressure distribution detection means are sandwiched between conductive sheets.

[0005] Furthermore, Patent Document 2 discloses a fuel cell stack equipped with a surface pressure measuring unit that measures the surface pressure of the electrolyte membrane, which changes in response to deformation of the electrolyte membrane. The surface pressure measuring unit in Patent Document 2 is composed of a plurality of surface pressure sensors provided on either the gas diffusion layer side or the gas flow path side between one of the gas diffusion layers and the gas flow path.

[0006] JP 2007-213882 A JP 2011-124132 A

[0007] Current technologies, including those disclosed in the above-mentioned patent documents, do not yet meet market needs, and the following problems exist. That is, although the dummy cell disclosed in the above-mentioned patent document 1 can certainly measure the pressure distribution in the in-plane direction, there is a concern that the dummy cell may become a resistance to the fuel cell depending on the arrangement of the dummy cell in the fuel cell stack. Similarly, the surface pressure measuring unit disclosed in patent document 2 is disposed by being buried inside the fuel cell, and therefore there is a concern that the dummy cell may become a resistance to the fuel cell.

[0008] The present disclosure has been made in consideration of the above-mentioned problems as an example, and aims to provide a control device and a fuel cell vehicle equipped with a fuel cell stack that can detect pressure distribution in the in-plane direction and calculate the water content distribution within the fuel cell without causing unnecessary resistance to the power generation operation of the fuel cell.

[0009] In order to solve the above problem, according to one aspect of the present disclosure, there is provided a fuel cell vehicle including a fuel cell stack in which a plurality of fuel cell cells are stacked and a pressure distribution measurement plate capable of measuring in-plane pressure distribution is interposed between an end plate and a current collector plate, and a control device that calculates the water content distribution in the in-plane direction of the fuel cell cells based on the in-plane pressure distribution.

[0010] According to the present disclosure, it is possible to detect the pressure distribution in the in-plane direction and calculate the water content distribution of the fuel cell while suppressing the influence on the power generation of the fuel cell.

[0011] FIG. 1 is a schematic diagram showing an example of the configuration of a fuel cell vehicle according to an embodiment; FIG. 2 is a schematic diagram explaining the components and functions of a fuel cell vehicle according to an embodiment; FIG. 3 is a schematic diagram showing an example of the configuration of a fuel cell stack according to an embodiment; FIG. 4 is a schematic diagram showing a fuel cell stack and peripheral devices according to an embodiment; FIG. 5 is a schematic diagram showing an example of the configuration of a pressure distribution measurement plate according to an embodiment; FIG. 6 is a schematic diagram showing a control device and peripheral devices according to an embodiment; FIG. 7 is a flowchart showing a method for adjusting the water content of a fuel cell according to an embodiment; FIG. 8 is an example showing an example of measurement of pressure distribution in an in-plane direction using a pressure distribution measurement plate according to an embodiment (before correction); FIG. 9 is an example showing an example of measurement of pressure distribution in an in-plane direction using a pressure distribution measurement plate according to an embodiment (after correction); and FIG. 10 is a graph explaining a method for adjusting the water content according to an embodiment.

[0012] Next, preferred embodiments of the present disclosure will be described. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted. Furthermore, configurations other than those described in detail below may be supplemented appropriately with elemental technologies and configurations related to known fuel cell systems and fuel cell vehicles, including those described in the patent documents mentioned above.

[0013] <Fuel Cell Vehicle FCV> Figures 1 and 2 are schematic diagrams showing an example of the configuration and functional blocks of a fuel cell vehicle FCV equipped with a fuel cell stack FC according to this embodiment. As shown in Figure 2, this fuel cell vehicle FCV is configured as a four-wheel drive vehicle in which drive torque output from a drive power source 21 that generates drive torque for the vehicle is transmitted to a left front wheel 3LF, a right front wheel 3RF, a left rear wheel 3LR, and a right rear wheel 3RR (hereinafter collectively referred to as "wheels 3" unless a distinction is required). In this embodiment, the drive power source 21 can be, for example, a known electric motor arranged on the front wheel side.

[0014] The electric motors serving as the driving force source 21 in this embodiment may be arranged one on each of the front and rear wheels, or one electric motor may be arranged for each wheel 3. In addition to the electric motor, the driving force source 21 may also include an internal combustion engine such as a gasoline engine, a diesel engine, or a gas turbine engine.

[0015] A power supply system that supplies the desired power to such a driving force source 21 includes a fuel cell stack FC formed by stacking a plurality of known fuel cell cells, such as PEFCs (polymer electrolyte fuel cells), a hydrogen gas supply unit including a known hydrogen tank 23 and piping, an air supply unit including a known compressor 31 and piping, a known secondary battery 50 such as a lithium ion secondary battery or a lead storage battery, a known converter 22, and a control device 100 that controls these.

[0016] The control device 100 in this embodiment also functions as a device that can determine deterioration by calculating the water content distribution in the in-plane direction of the fuel cell 11 based on the in-plane pressure distribution in the fuel cell 11, which will be described later. In this power supply system, the fuel cell stack FC and the secondary battery 50 are each capable of supplying power to a load including the electric motor described above.

[0017] As shown in Fig. 2, the fuel cell stack FC is connected to a load including the above-mentioned driving force source 21 (electric motor) via the above-mentioned converter 22 and wiring. Also as shown in Fig. 2, the current and voltage in the fuel cell stack FC are respectively detected by a known current sensor SR. １ and voltage sensor SR ２ is detected by

[0018] The converter 22 is configured to include a known AC / DC converter that converts DC current to AC current, and a known DC / DC converter that adjusts the voltage of DC current to a desired voltage. As an example, the converter 22 of this embodiment has functions such as receiving a control signal from the control device 100 to set the output voltage that is generated and output by the fuel cell stack FC, and boosting the power generated by the fuel cell stack FC to a desired voltage when supplying it to a load.

[0019] In addition, the fuel cell vehicle FCV of this embodiment is equipped with the above-mentioned driving force source 21, electric steering device 8, and brake devices 4LF, 4RF, 4LR, and 4RR (hereinafter collectively referred to as "brake device 4" unless a distinction is required) as equipment used for driving control.

[0020] The driving force source 21 outputs driving torque that is transmitted to the front drive shaft 2F and the rear drive shaft 2R via a transmission, a front wheel differential mechanism 5F, and a rear wheel differential mechanism 5R (not shown). The driving of the driving force source 21 and the transmission is controlled by a known control device that includes one or more electronic control units (ECUs: Electronic Control Units).

[0021] The front wheel drive shaft 2F is provided with an electric steering device 8. The electric steering device 8 includes an electric motor and a gear mechanism (not shown), and is controlled by a vehicle drive control device 20 to adjust the steering angles of the left front wheel 3LF and the right front wheel 3RF.

[0022] The vehicle drive control device 20 includes one or more known electronic control units (ECUs) that control the drive of a drive force source 21 that outputs drive torque for the fuel cell vehicle FCV, an electric steering device 8 that controls the steering wheel 9 or the steering angle of the steering wheels, and a brake device 4 that controls the braking force of the fuel cell vehicle FCV. The vehicle drive control device 20 may also have a function of controlling the drive of a transmission that changes the speed of the output output from the drive force source 21 and transmits it to the wheels 3.

[0023] As shown in FIG. 2, in the hydrogen gas supply section for supplying fuel (hydrogen) gas to the fuel cell stack FC, the hydrogen gas stored in the hydrogen tank 23 is supplied to the anode side flow path of the fuel cell stack FC described above via a hydrogen intake valve 32a having a known structure installed in the hydrogen supply flow path.

[0024] A portion of the hydrogen gas discharged from the fuel cell stack FC may be returned to the hydrogen supply flow path by a circulation flow path and a known circulation pump 45. The remainder of the hydrogen gas discharged from the fuel cell stack FC may be diluted by a known diluter 41 at a predetermined timing under the control of the control device 100 via the opening and closing operation of a known hydrogen exhaust valve 32b, and then released (exhausted) to the atmosphere.

[0025] 2, the air supply unit for supplying oxygen gas (air) to the fuel cell stack FC is configured to include, in addition to the above-mentioned compressor 31, a known air intake valve 32c and an air exhaust valve (back pressure valve) 32d for adjusting the amount of oxygen (air) supplied to the fuel cell 1. The air supply unit may further include a known flow rate sensor (not shown) capable of measuring the flow rate of air supplied to the fuel cell stack FC.

[0026] The air taken in by the compressor 31 is supplied to the cathode-side flow path in the fuel cell stack FC via an air intake valve 32c and a known humidifier (not shown), etc. The air supplied to the fuel cell 1 is also supplied to the above-mentioned diluter 41 as cathode off-gas under the control of an air exhaust valve (back pressure valve) 32d by the control device 100.

[0027] The control device 100 is configured to include one or more processors (CPUs (Central Processing Units)) and one or more memories communicatively connected to the one or more processors. The control device 100 may be configured to be connectable to a known external network NET such as the Internet via various known communication devices CD, such as a smartphone.

[0028] The control device 100 is connected to a compressor 31, valves 32 (hydrogen intake valve 32a, hydrogen exhaust valve 32b, air intake valve 32c, and air exhaust valve 32d), a current sensor SR, and other related devices, either directly or via a communication means such as a CAN (Controller Area Network) or a LIN (Local Internet). １ and voltage sensor SR ２ Known sensors SR such as the above are electrically connected to the sensor.

[0029] The fuel cell stack 10 of this embodiment has a stack structure in which a plurality of known fuel cell cells, each having an electromotive force of, for example, about 1 V, are connected in series and stacked on top of each other. As an example, the fuel cell stack 10 of this embodiment can be a polymer electrolyte fuel cell (PEFC) having a structure in which fuel cell cells are connected in series within a pair of known end plates that pressurize and hold the fuel cells at both ends so as to provide the system voltage required by a fuel cell vehicle (FCV).

[0030] Each fuel cell constituting the fuel cell stack 10 has a structure in which a known MEA (membrane electrode assembly) is interposed between a pair of known separators installed on the fuel electrode side and the air electrode side. This MEA is configured to include at least a known cathode catalyst layer, a known anode catalyst layer disposed opposite the cathode catalyst layer, and a known polymer electrolyte membrane disposed between the cathode catalyst layer and the anode catalyst layer. The membrane electrode assembly may further include a known air electrode-side gas diffusion layer and a known fuel electrode-side gas diffusion layer. The cathode catalyst layer in this embodiment is configured in such a way that a known catalytic metal, such as precious metal particles such as platinum (Pt) nanoparticles or platinum-cobalt (Pt—Co) particles, is bonded to a catalyst support, exemplified by a metal material such as stainless steel or titanium, or a carbon material.

[0031] <Detailed Structure of Fuel Cell Stack 10> Next, the detailed structure of the fuel cell stack 10 according to this embodiment will be described with reference to Figures 3 to 5. As shown in Figure 3, the fuel cell stack 10 according to this embodiment includes a plurality of stacked fuel cells 11, and a pair of current collector plates 14 (first current collector plate 14A, second current collector plate 14B) from which current can be extracted are disposed at both ends of the stacked fuel cells 11. As can be seen from Figure 3 and other figures, well-known insulating plates 15 (first insulating plate 15A, second insulating plate 15B) are provided on the outer sides of the pair of current collector plates 14. Furthermore, a pair of end plates 13 (first end plate 13A, second end plate 13B) are provided on the outer sides of the pair of insulating plates 15, and a predetermined load is applied to the plurality of fuel cells 11 by the pair of end plates 13 and well-known fastening bolts (not shown).

[0032] 3 and 4 , a pressure distribution measurement plate 12 capable of measuring the in-plane pressure distribution of, for example, the fuel cell 11 is interposed between one of the first end plates 13A and the first current collector plate 14A. In this way, the fuel cell stack 10 of this embodiment is configured by stacking a plurality of fuel cells 11, and by interposing a pressure distribution measurement plate 12 capable of measuring the in-plane pressure distribution of the fuel cell 11 between the end plate 13 and the current collector plate 14. In this embodiment, the pressure distribution measurement plate 12 is interposed between the first end plate 13A and the first current collector plate 14A, but it may also be interposed between the second end plate 13B and the second current collector plate 14B, or a pressure distribution measurement plate 12 may be interposed between both end plates.

[0033] 4, each of the pair of end plates 13 in the fuel cell stack 10 is provided with an air inlet Ain for receiving a supply of oxygen gas (air) from the air supply unit, and an air outlet Aout through which the cathode off-gas is discharged. Similarly, each of the pair of end plates 13 is provided with a hydrogen inlet Hin for receiving a supply of hydrogen gas from the hydrogen supply unit, and a hydrogen outlet Hout through which the anode off-gas is discharged.

[0034] Furthermore, the fuel cell stack 10 of this embodiment is provided with a cooling water inlet Win through which cooling water sent from a cooling water source 25 via a known circulation pump 24 flows in, and a cooling water inlet Wout through which cooling water that has passed through the fuel cell stack 10 is discharged. In this embodiment, the flow path of the cooling water flowing into the fuel cell stack 10 is provided with a known flow rate sensor SR3 that can measure the flow rate of the cooling water flowing into the fuel cell stack 10, and a known temperature sensor SR4 that can measure the temperature of the cooling water flowing into the fuel cell stack 10.

[0035] <Structure of Pressure Distribution Measurement Plate 12> Next, the structure of the pressure distribution measurement plate 12 in this disclosure will be described using Figure 5. As described above, the pressure distribution measurement plate 12 is disposed between the end plate 13 and the current collector plate 14, and is configured to have the function of measuring the in-plane pressure distribution in the fuel cell stack 10 (more specifically, the fuel cell 11). Note that, as shown in Figures 3 and 4, the pressure distribution measurement plate 12 in this embodiment is preferably interposed between the end plate 13 and the current collector plate 14, particularly between the current collector plate 14 and the insulating plate 15.

[0036] 5, the pressure distribution measurement plate 12 is configured to include a plurality of pressure sensors 12a arranged in a grid pattern corresponding to the power regions of the stacked fuel cell cells 11, and an insulating substrate 12b that supports these pressure sensors 12a. Note that the pressure sensors 12a in this embodiment are arranged in 10 columns and 7 rows, but this is not limiting and any number of sensors may be arranged corresponding to the electrode regions of the fuel cell cells 11. Also, although the pressure sensors 12a in this embodiment are arranged in a grid pattern corresponding to the electrode regions described above, they do not have to be arranged in a grid pattern as long as they can detect pressure distribution in the in-plane direction.

[0037] The pressure sensor 12a in this embodiment may be, for example, a known pressure sensor configured with a piezoelectric (PZT) element. Each pressure sensor 12a arranged on the insulating substrate 12b is a known voltage detection sensor SR capable of individually detecting voltage via the above-mentioned piezoelectric element. ５ As a result, the control device 100 can detect the voltage from the pressure sensor 12a disposed at an arbitrary position on the insulating substrate 12b to the voltage detection sensor SR ５ It is possible to detect the voltage via

[0038] The pressure distribution measurement plate 12 of this embodiment configured as described above is not disposed in the region where the fuel cell cells 11 are stacked inside the pair of current collector plates 14, but is disposed outside the current collector plates 14 (between the end plates 13). As a result, compared to when the pressure distribution measurement plate 12 of this embodiment is disposed inside the pair of current collector plates 14, it is possible to eliminate the cost of increasing conductivity so as not to inhibit the current generated in the fuel cell cells 11, and it is also possible to reduce the risk of corrosion of the sensor and improve durability.

[0039] <Control device 100> Next, the configuration of the control device 100 will be described with reference to Fig. 6. That is, the control device 100 in this embodiment includes the pressure distribution measurement plate 12 and the voltage detection sensor SR ５ and a function of calculating the water content distribution in the in-plane direction of the fuel cell 11 based on the in-plane pressure distribution.

[0040] Such a control device 100 includes a piezoelectric voltage measurement unit 101, a pressure distribution calculation unit 102, a pressure distribution correction unit 103, a pressure distribution adjustment unit 104, and a presentation control unit 105. Each of these units may be a function realized by a processor such as a CPU executing a computer program, but some or all of them may be configured using analog circuits.

[0041] The piezoelectric voltage measurement unit 101 is the voltage detection sensor SR ５ The pressure distribution calculation unit 102 is configured to have a function of detecting the voltage value at the pressure sensor 12 a via the pressure distribution calculation unit 102. The pressure distribution calculation unit 102 is configured to have a function of calculating the in-plane pressure distribution in the fuel cell 11 based on the voltage value at the pressure sensor 12 a.

[0042] The pressure distribution correction unit 103 is configured to have the function of correcting the in-plane pressure distribution measured before the fluid flows into the fuel cell stack 10, based on pressure changes that occur as the fluid is supplied to the fuel cell stack 10. Examples of fluids that can be supplied to the fuel cell stack 10 include oxygen gas (air) supplied from the air supply unit, hydrogen gas supplied from the hydrogen supply unit, and cooling water that flows in from the cooling water source 25.

[0043] The pressure distribution adjustment unit 104 is configured to have the function of adjusting at least one of the flow rate and temperature of the cooling water, the flow rate of the intake air, and the rotation speed of the circulation pump based on the calculated water content distribution in the in-plane direction so that the water content at each point in the in-plane direction falls within a target range.

[0044] The presentation control unit 105 executes a process of presenting various information such as the moisture distribution and degradation state of the fuel cell stack FC via a presentation device PD including a known in-vehicle speaker SP and display DP. The presentation control unit 105 may present the above-mentioned various information to the occupant via an in-vehicle presentation device DD, or may access and present the information on an external terminal such as a smartphone carried by the occupant.

[0045] <Method for Adjusting Water Amount in Fuel Cell Stack> Next, with reference to FIG. 7 , a method for adjusting the water amount in the fuel cell stack 10 that can be executed by the control device 100 in this embodiment will be described. Note that this water adjustment method may be used as an algorithm of a computer-readable program. A program having such an algorithm may be distributed so that it can be downloaded to the fuel cell vehicle FCV via a known network, or may be distributed in the form of being stored on a recording medium. The following description will be given taking as an example a case where a user starts up the system of the fuel cell vehicle FCV and starts driving.

[0046] First, in step 1, the control device 100 determines whether the fuel cell stack 10 has started up after the system of the fuel cell vehicle FCV has started up. More specifically, the control device 100 may determine whether the fuel cell stack FC has reached an appropriate temperature based on a known temperature sensor (not shown) to determine whether the fuel cell stack FC is in a state where it can be stably driven.

[0047] After the fuel cell stack 10 is started in step 1, in the following step 2, the control device 100 measures the uncorrected pressure distribution in the fuel cell 11. More specifically, the piezoelectric voltage measurement unit 101 of the control device 100 measures the uncorrected pressure distribution in the fuel cell 11 using the voltage detection sensor SR ５ The voltage values ​​of the plurality of pressure sensors 12a on the pressure distribution measuring plate 12 are detected via the respective sensors.

[0048] At this time, as shown in Fig. 8, for example, the piezoelectric voltage measurement unit 101 can determine "High (H)" when the voltage value of the pressure sensor 12a at any location is higher than a predetermined reference value, and can determine "Low (L)" when the voltage value is lower than the predetermined reference value. This makes it possible to calculate the pressure distribution within the pressure distribution measurement plate 12 based on the detection values ​​of the pressure sensors 12a, as shown in Fig. 8.

[0049] In this embodiment, the pressure distribution is detected based on whether the voltage is high or low relative to a predetermined reference value, but the present disclosure is not limited to this. For example, instead of the above, the piezoelectric voltage measurement unit 101 may calculate the pressure distribution using the voltage values ​​detected from the multiple pressure sensors 12a as they are, or may determine the above-mentioned "High (H)" or "Low (L)" based on the relative value (high or low) of any pressure sensor 12a relative to the average voltage value of the surrounding area.

[0050] After measuring the pre-correction pressure distribution in step 2, in the following step 3, the control device 100 starts supplying fluids (hydrogen gas, air (oxygen gas), and cooling water) to the fuel cell stack 10 so that power generation occurs in the fuel cell 11.

[0051] In step 3, the control device 100 may correct the in-plane pressure distribution measured before the fluid flows in, based on the pressure change that accompanies the supply of the fluid to the fuel cell stack 10. In this case, the pressure change in the separator flow path of the fuel cell 11 can be calculated as follows. That is, as a prerequisite for calculating the pressure change, it is first assumed that the fuel cell stack 10 is operated in a state where the following five conditions are satisfied: (Condition 1) The temperature inside the separator is constant. (Condition 2) The flow rate of gas that permeates the electrolyte membrane is small and therefore can be ignored. (Condition 3) All water produced by the reaction inside the fuel cell 11 is discharged as gas. (Condition 4) According to the gas equation of state, pressure is proportional to the number of gas molecules. (Condition 5) The current density generated in the fuel cell 11 by power generation is constant.

[0052] Under the above conditions 1 to 5, two water molecules are produced every time one oxygen molecule is consumed in the reaction at the air electrode of the fuel cell 11. In this case, the number of gas molecules M(x) from the inlet (origin (x = 0)) to the outlet (x = L) in the separator flow path of the fuel cell 11 operating at a current value of "i" amperes can be calculated using the following equation 1. In the following equation 1, it is assumed that the flow rate of intake gas drawn into the fuel cell 11 is St times the amount of oxygen required to sweep the above-mentioned current i. In the following equation 1, "F" represents the well-known Faraday constant. Formula 1

[0053]

[0054] Since the number of gas molecules at position x along the flow direction of the separator is calculated using Equation 1 above, the pressure value at position x can be calculated based on the gas state equation described above. Note that pressure changes due to the inflow of hydrogen gas and cooling water can also be calculated in the same manner as above. This makes it possible to calculate pressure changes due to the inflow of fluid into the fuel cell 11 (separator). Note that the pressure change due to the supply of fluid to the fuel cell stack 10 may be calculated using other known calculation formulas in addition to the calculation method described above.

[0055] Then, in step 3, the control device 100 can correct the in-plane pressure distribution (see Figure 8) measured before the fluid flows in, for example, as illustrated in Figure 9, based on the pressure change that accompanies the start of fluid supply to the fuel cell 11.

[0056] Next, in step 4, the control device 100 calculates the water content distribution in the in-plane direction of the fuel cell 11 corresponding to the in-plane pressure distribution calculated through steps 2 and 3. More specifically, the control device 100 calculates the water content distribution in the in-plane direction of the fuel cell 11 based on information (pressure-water content characteristic information) that defines the relationship between the water content and the pressure value that has been stored in advance.

[0057] The pressure-moisture content characteristic information can be calculated in advance by experiment or simulation. Similarly, the appropriate water content range (target water content range) when the fuel cell 11 is operating (generating electricity) according to predetermined specifications can also be calculated in advance by experiment or simulation.

[0058] Therefore, in the following step 5, the control device 100 determines whether the water content in the in-plane direction of the fuel cell 11 calculated in step 4 is within the target water content range. If the water content in the in-plane direction of the fuel cell 11 is within the target water content range in step 5 (Yes in step 5), the control device 100 proceeds to step 7. On the other hand, if the water content in the in-plane direction of the fuel cell 11 is not within the target water content range in step 5 (No in step 5), the control device 100 proceeds to step 6, where a process for adjusting the water content distribution is performed.

[0059] That is, in step 6, the control device 100 performs an adjustment process so that the water content at each point in the in-plane direction falls within a target water content range, based on the water content distribution in the in-plane direction calculated in step 4. More specifically, as the adjustment process, the control device 100 may adjust at least one of the flow rate and temperature of the cooling water flowing into the fuel cell 11, the flow rate of intake air, and the rotation speed of the circulation pump 24 that sends cooling water to the fuel cell 11.

[0060] As an example, FIG. 10( a) shows the change in water content Q when the temperature of the cooling water flowing into the fuel cell 11 is adjusted. In FIGS. 10( a) to 10(c), the horizontal axis represents the distance D to the cathode outlet of the fuel cell 11, with the cathode inlet of the fuel cell 11 being the origin, and the vertical axis represents the water content Q. As can be seen from FIG. 10( a), when the temperature of the cooling water flowing into the fuel cell 11 is lowered, the state can be shifted upward (i.e., in the direction in which the water content increases) in a parallel manner from the state shown by the solid line. Similarly, as shown in FIG. 10( a), when the temperature of the cooling water flowing into the fuel cell 11 is increased, the state can be shifted downward (i.e., in the direction in which the water content decreases) in a parallel manner from the state shown by the solid line. In this way, the control device 100 can uniformly increase or decrease the water content from the cathode inlet to the outlet of the fuel cell 11 by increasing or decreasing the temperature of the cooling water flowing into the fuel cell 11.

[0061] As another example, Figure 10(b) shows the change in water content Q when the flow rate of the cooling water flowing into the fuel cell 11 is adjusted. That is, as can be seen from Figure 10(b), when the flow rate of the cooling water flowing into the fuel cell 11 is reduced, the water content at the cathode outlet side can be preferentially increased compared to the cathode inlet, from the state shown by the solid line. Similarly, as shown in Figure 10(b), when the flow rate of the cooling water flowing into the fuel cell 11 is increased, the water content at the cathode outlet side can be preferentially decreased compared to the cathode inlet, from the state shown by the solid line. In this way, by increasing or decreasing the flow rate of the cooling water flowing into the fuel cell 11, the control device 100 can increase or decrease the water content at the cathode outlet of the fuel cell 11 while maintaining the water content at the cathode inlet side.

[0062] FIG. 10( c) shows the change in water content Q when the flow rate of intake air flowing into the fuel cell 11 is adjusted. That is, as can be seen from FIG. 10( c), when the flow rate of intake air flowing into the fuel cell 11 is reduced, the water content at the cathode inlet side can be preferentially increased relative to the cathode outlet side, from the state shown by the solid line. Similarly, as shown in FIG. 10( c), when the flow rate of intake air flowing into the fuel cell 11 is increased, the water content at the cathode inlet side can be preferentially decreased relative to the cathode outlet side, from the state shown by the solid line. In this way, by increasing or decreasing the flow rate of intake air flowing into the fuel cell 11, the control device 100 can increase or decrease the water content at the cathode inlet side of the fuel cell 11 while maintaining the water content at the cathode outlet side.

[0063] Similarly, the control device 100 can increase or decrease the water content in the fuel cell 11 from the cooling water inlet to the outlet by increasing or decreasing the rotation speed of the circulation pump 24 that supplies cooling water to the fuel cell 11. In this way, the control device 100 can adjust the in-plane water content in the fuel cell 11 to be within a target water content range by adjusting at least one of the flow rate and temperature of the cooling water flowing into the fuel cell 11, the flow rate of intake air, and the rotation speed of the circulation pump 24 that supplies cooling water to the fuel cell 11.

[0064] After adjusting the water content distribution in step 6, the control device 100 determines in the following step 7 whether the system has been turned off, for example, when the fuel cell vehicle FCV arrives at its destination. If the system has been turned off in step 7, the control device 100 completes the water content adjustment method of this embodiment. On the other hand, if the system has not been turned off in step 7, the control device 100 proceeds to step 1 and repeats the above-described process.

[0065] According to the control device 100 and the method for adjusting the water content in a fuel cell stack of this embodiment described above, the pressure distribution in the in-plane direction is detected using the pressure distribution measuring plate 12 placed in a position where the impact on the power generation of the fuel cell 11 is minimized, thereby improving the durability of the pressure distribution measuring plate and the reliability of measurements, and making it possible to calculate the water content distribution of the fuel cell.

[0066] <Computer program, recording medium> The computer program that realizes the measurement of the in-plane pressure distribution in the fuel cell by the control device 100 and the subsequent water content adjustment method can cause one or more processors to execute processing (algorithm) that includes measuring the in-plane pressure distribution via a pressure distribution measurement plate interposed between the end plate and the current collector plate of the fuel cell stack, and calculating the water content distribution in the in-plane direction of the fuel cell based on the measured in-plane pressure distribution.

[0067] Furthermore, the computer program for realizing the above-described functions of the control device 100 can execute, in addition to the above-described algorithm, a calculation of the water content distribution in the in-plane direction of the fuel cell corresponding to the in-plane pressure distribution based on pre-stored pressure-water content characteristic information. Furthermore, in addition to the above-described algorithm, the computer program for realizing the above-described functions of the control device 100 can execute, in addition to the above-described algorithm, a correction of the in-plane pressure distribution measured before fluid supply (inflow of air, hydrogen gas, or coolant) to the fuel cell stack based on pressure changes accompanying the inflow. Furthermore, in addition to the above-described algorithm, the computer program for realizing the above-described functions of the control device 100 can execute, in addition to the above-described algorithm, adjustment of at least one of the flow rate and temperature of the coolant, the flow rate of the intake air, and the rotation speed of the circulation pump based on the calculated in-plane water content distribution so that the water content at each location in the in-plane direction falls within a target water content range.

[0068] Furthermore, such a computer program may be stored in, for example, a known recording medium as described above, or may be downloaded to the fuel cell vehicle FCV from a known server such as a cloud server.

[0069] Although the preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the technology of the present disclosure is not limited to such examples. It is clear that a person skilled in the art of the technology to which the present disclosure pertains can conceive of various modified or altered examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure.

[0070] REFERENCE SIGNS LIST 10 fuel cell stack 11 fuel cell cell 12 pressure distribution measurement plate 13 end plate 14 current collector plate 15 insulating plate 20 vehicle drive control device 100 control device 101 piezoelectric voltage measurement unit 102 pressure distribution calculation unit 103 pressure distribution correction unit 104 pressure distribution adjustment unit 105 presentation control unit FCV fuel cell vehicle

Claims

1. a fuel cell stack in which a plurality of fuel cell units are stacked and a pressure distribution measurement plate capable of measuring an in-plane pressure distribution is interposed between an end plate and a current collector plate; a control device that calculates a water content distribution in an in-plane direction of the fuel cell based on the in-plane pressure distribution; Including, the pressure distribution measurement plate includes a plurality of pressure sensors arranged in correspondence with the power regions of the stacked fuel cells, the control device calculates a water content distribution in an in-plane direction of the fuel cell corresponding to the in-plane pressure distribution in the power region acquired via the pressure sensor based on pre-stored pressure-water content characteristic information; Fuel cell car.

2. the control device corrects the in-plane pressure distribution measured before the fluid flows into the fuel cell stack based on a pressure change caused by the fluid being supplied to the fuel cell stack. The fuel cell vehicle according to claim 1 .

3. The control device includes: Based on the calculated moisture content distribution in the in-plane direction, at least one of the flow rate and temperature of the cooling water, the flow rate of the intake air, and the rotation speed of the circulation pump is adjusted so that the moisture content at each point in the in-plane direction falls within a target moisture content range. The fuel cell vehicle according to claim 2.