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

Technical Field

[0001] The present disclosure relates to a fuel cell vehicle.

Background Art

[0002] In modern society, means of transportation are indispensable, and various vehicles such as automobiles are moving on the road in daily life. Among them, as a new power source for supplying driving force to vehicles, fuel cells with relatively low environmental impact have attracted attention.

[0003] In such a fuel cell, 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 obtained by their chemical reaction. It is known that the electrolyte membrane that constitutes a part of the fuel cell has a lower resistance when the water content increases, while the resistance increases when it 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, causing 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, management of moisture in the fuel cell stack mounted on the vehicle is important.

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

[0005] Further, Patent Document 2 discloses a fuel cell stack provided with a surface pressure measurement unit for measuring the surface pressure of the electrolyte membrane that changes according to the deformation of the electrolyte membrane. The surface pressure measurement unit in this 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 part side between one of the gas diffusion layers and the gas flow path part.

Prior Art Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2007-213882 [Patent Document 2] Japanese Patent Publication No. 2011-124132 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Not limited to the aforementioned patent documents, current technology still cannot be said to meet market needs, and the following challenges exist. In other words, while the dummy cell disclosed in Patent Document 1 above can certainly measure the pressure distribution in the in-plane direction, there is a concern that it may become a source of resistance to the fuel cell depending on the arrangement of the dummy cell within the fuel cell stack. Similarly, the surface pressure measuring unit disclosed in Patent Document 2 is designed to be embedded inside the fuel cell, so there is a concern that it may become a source of resistance to the fuel cell.

[0008] This disclosure has been made in view of the above-mentioned problems as an example, and aims to provide a fuel cell vehicle equipped with a control device and fuel cell stack capable of detecting the pressure distribution in the in-plane direction and calculating the water content distribution within the fuel cell without creating extra resistance to the power generation operation of the fuel cell. [Means for solving the problem]

[0009] To solve the above problems, according to one aspect of this disclosure, multiple fuel cell cells are stacked, The fuel cell A fuel cell stack comprising a pressure distribution measuring plate capable of measuring the in-plane pressure distribution 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 cell based on the in-plane pressure distribution, The fuel cell stack has an insulating plate on the outside of the current collector plate, The pressure distribution measuring plate is Interposed between the current collector plate and the insulating plate, The stacked fuel cell cells electrode area Corresponding to In a grid patternThe control device comprises a plurality of pressure sensors arranged in a row, and based on the pressure-water content characteristic information that has been stored in advance, the control device acquires the information via the plurality of pressure sensors. electrode area A fuel cell vehicle is provided that calculates the water content distribution in the in-plane direction of the fuel cell cell corresponding to the in-plane pressure distribution. [Effects of the Invention]

[0010] According to this 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 impact on power generation of the fuel cell. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing an example configuration of a fuel cell vehicle according to the embodiment. [Figure 2] This is a schematic diagram illustrating the various components and functions of a fuel cell vehicle according to an embodiment of this model. [Figure 3] This is a schematic diagram showing an example configuration of a fuel cell stack according to the embodiment. [Figure 4] This is a schematic diagram showing a fuel cell stack and peripheral equipment according to an embodiment. [Figure 5] This is a schematic diagram showing an example of the configuration of a pressure distribution measuring plate according to an embodiment. [Figure 6] This is a schematic diagram showing the control device and peripheral devices according to the embodiment. [Figure 7] This is a flowchart showing a method for adjusting the water content of a fuel cell cell according to an embodiment. [Figure 8] This is an example showing the measurement of the pressure distribution in the in-plane direction (before correction) using the pressure distribution measurement plate in the embodiment. [Figure 9] This is an example showing a measurement of the in-plane pressure distribution (after correction) using the pressure distribution measurement plate in the embodiment. [Figure 10] This graph illustrates the method for adjusting the water content according to the embodiment. [Modes for carrying out the invention]

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

[0013] <Fuel cell vehicle FCV> FIG. 1 and FIG. 2 are schematic diagrams respectively showing a configuration example and a functional block of a fuel cell vehicle FCV including a fuel cell stack FC according to the present embodiment. As shown in FIG. 2, this fuel cell vehicle FCV is configured as a four-wheel drive vehicle that transmits the drive torque output from a drive power source 21 that generates the drive torque of the vehicle to the left front wheel 3LF, the right front wheel 3RF, the left rear wheel 3LR, and the right rear wheel 3RR (hereinafter, collectively referred to as "wheel 3" when no particular distinction is required). The drive power source 21 can be exemplified by a known electric motor disposed on the front wheel side in the present embodiment.

[0014] Note that the electric motors as the drive power source 21 in the present embodiment may be arranged one by one on the front wheel side and the rear wheel side, or may be in a form in which one electric motor is arranged on each wheel 3. In addition to the above-mentioned electric motor, the drive power source 21 may further 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 desired power to such a drive power source 21 includes, for example, a fuel cell stack FC configured by stacking a plurality of known fuel cell cells such as a PEFC (polymer electrolyte fuel cell), a hydrogen gas supply unit including a known hydrogen tank 23 and piping respectively, an air supply unit including a known compressor 31 and piping respectively, 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] Furthermore, the control device 100 in this embodiment also functions as a device capable of determining deterioration by calculating the water content distribution in the in-plane direction of the fuel cell cell 11 based on the in-plane pressure distribution of the fuel cell cell 11, which will be described later. In this power supply system, each of the fuel cell stack FC and the secondary battery 50 is capable of supplying power to the load, including the electric motor described above.

[0017] As shown in Figure 2, this fuel cell stack FC is connected to a load, including, for example, the drive source 21 (electric motor) described above, via the converter 22 and wiring. Also as shown in Figure 2, the current and voltage in the fuel cell stack FC are detected by a known current sensor SR1 and a voltage sensor SR2, respectively.

[0018] The converter 22 includes a known AC / DC converter that converts between direct current and alternating current, and a known DC / DC converter that adjusts the voltage of the direct current to a desired voltage. For example, the converter 22 of this embodiment has a function to set the output voltage that the fuel cell stack FC generates and outputs in response to a control signal from the control device 100, and a function to boost the voltage of the power generated by the fuel cell stack FC to a desired voltage when supplying it to a load.

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

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

[0021] An electric steering device 8 is provided on the front wheel drive shaft 2F. The electric steering device 8 includes an electric motor and a gear mechanism (not shown) and is controlled by the 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 power source 21 that outputs drive torque to a fuel cell vehicle (FCV), an electric steering device 8 that controls the steering angle of the steering wheel 9 or 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 to control the drive of a transmission that changes the speed of the output output from the power source 21 and transmits it to the wheels 3.

[0023] Furthermore, as shown in Figure 2, in the hydrogen gas supply unit 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 via a hydrogen intake valve 32a having a known structure installed in the hydrogen supply flow path.

[0024] Furthermore, a portion of the hydrogen gas discharged from the fuel cell stack FC may be recirculated into the hydrogen supply channel by a circulation channel and a known circulation pump 45. The remaining hydrogen gas discharged from the fuel cell stack FC may be diluted by a known diluent 41 at a predetermined timing via the opening and closing operation of a known hydrogen exhaust valve 32b under the control of the control device 100, and then released into the atmosphere (exhausted).

[0025] On the other hand, as shown in Figure 2, the air supply unit for supplying oxygen gas (air) to the fuel cell stack FC is configured to include, in addition to the compressor 31 described above, a known air intake valve 32c and an air discharge valve (back pressure valve) 32d for adjusting the amount of oxygen (air) supplied to the fuel cell 1. Furthermore, this air supply unit may also include a known flow 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 then supplied to the cathode-side flow path in the fuel cell stack FC via the air intake valve 32c and a known humidifier (not shown). The air supplied to the fuel cell 1 is also supplied to the diluent 41 as cathode-off gas under the control of the air discharge valve (back pressure valve) 32d by the control device 100.

[0027] The control device 100 is a processor (CPU (Central Processing Unit)) The control device 100 is configured to include a processor and one or more memories that are communicatively connected to the one or more processors. For example, 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] Such a control device 100 can be directly connected to or connected to CAN (Controller Area Network) or The compressor 31 and each valve 32 are controlled via a communication means such as LIN (Local Internet). (Hydrogen intake valve 32a, hydrogen exhaust valve 32b, air intake valve 32c, and air exhaust valve 32d), known sensors SR such as current sensor SR1 and voltage sensor SR2 are electrically connected.

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

[0030] Furthermore, each fuel cell 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, respectively. This MEA comprises at least a known cathode catalyst layer, a known anode catalyst layer positioned opposite the cathode catalyst layer, and a known polymer electrolyte membrane positioned between the cathode catalyst layer and the anode catalyst layer. The membrane electrode assembly may further comprise a known air electrode side gas diffusion layer and a fuel electrode side gas diffusion layer, respectively. In this embodiment, the cathode catalyst layer is in a form in which a known catalyst metal, such as platinum (Pt) nanoparticles or platinum-cobalt (Pt-Co) particles, is bonded to a catalyst support material, such as a metal material like 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 in this embodiment will be described using Figures 3 to 5. As shown in Figure 3, the fuel cell stack 10 in this embodiment consists of multiple fuel cell cells 11 stacked on top of each other, and a pair of current collector plates 14 (first current collector plate 14A, second current collector plate 14B) capable of extracting current are placed at both ends of the stacked fuel cell cells 11. As can be understood from Figure 3 and other figures, known insulating plates 15 (first insulating plate 15A, second insulating plate 15B) are provided on the outside 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 outside of the pair of insulating plates 15, and a predetermined load is applied to the multiple fuel cell cells 11 by these end plates 13 and known fastening bolts (not shown).

[0032] As shown in Figures 3 and 4, a pressure distribution measuring plate 12 capable of measuring the in-plane pressure distribution in the fuel cell 11 is interposed between either the first end plate 13A and the first current collector plate 14A. Thus, the fuel cell stack 10 of this embodiment consists of a plurality of fuel cell cells 11 stacked on top of each other, with a pressure distribution measuring plate 12 capable of measuring the in-plane pressure distribution in the fuel cell cells 11 interposed between the end plate 13 and the current collector plate 14. In this embodiment, the pressure distribution measuring 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 the pressure distribution measuring plate 12 may be interposed between both.

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

[0034] Furthermore, the fuel cell stack 10 of this embodiment is provided with a cooling water inlet Win into which cooling water sent from a cooling water source 25 via a known circulation pump 24 flows, and a cooling water inlet Wout into 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 sensor SR3 capable of measuring the flow rate of the cooling water flowing into the fuel cell stack 10, and a known temperature sensor SR4 capable of measuring the temperature of the cooling water flowing into the fuel cell stack 10.

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

[0036] As shown in Figure 5, the pressure distribution measuring plate 12 is composed of 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. In this embodiment, the pressure sensors 12a are arranged in a 10x7 grid pattern, but the configuration is not limited to this, and any number may be arranged corresponding to the electrode regions of the fuel cell cells 11. Furthermore, although the pressure sensors 12a in this embodiment are arranged in a grid pattern corresponding to the electrode regions as described above, they do not have to be arranged in a grid pattern as long as the pressure distribution in the in-plane direction can be detected.

[0037] In this embodiment, a known pressure sensor composed of a piezoelectric (PZT) element can be used as the pressure sensor 12a. Each pressure sensor 12a arranged on the insulating substrate 12b is electrically connected to a known voltage detection sensor SR5 that can individually detect voltage via the piezoelectric element. This allows the control device 100 to detect voltage from the pressure sensors 12a placed at any position on the insulating substrate 12b via the voltage detection sensor SR5.

[0038] As described above, the pressure distribution measuring plate 12 of this embodiment is not located in the area where the fuel cell cells 11 are stacked inside the pair of current collector plates 14, but is located outside the current collector plates 14 (between it and the end plate 13). This eliminates the cost of increasing conductivity to avoid hindering the current generated by the fuel cell cells 11, compared to the case where the pressure distribution measuring plate 12 is located inside the pair of current collector plates 14, and further reduces the risk of sensor corrosion, thereby improving durability.

[0039] <Control device 100> Next, the configuration of the control device 100 will be described using Figure 6. Specifically, the control device 100 in this embodiment has the function of detecting the in-plane pressure distribution of the fuel cell cell 11 via the pressure distribution measuring plate 12 and voltage detection sensor SR5 described above, and the function of calculating the water content distribution in the in-plane direction of the fuel cell cell 11 based on this in-plane pressure distribution.

[0040] Such a control device 100 includes a piezo voltage measurement unit 101, a pressure distribution calculation unit 102, a pressure distribution correction unit 103, a pressure distribution adjustment unit 104, and a display control unit 105, etc. Each of these units may be a function realized by the execution of a computer program by a processor such as a CPU, but some or all of them may be made up of analog circuits.

[0041] The piezoelectric voltage measurement unit 101 is configured to have the function of detecting the voltage value at the pressure sensor 12a via the voltage detection sensor SR5 described above. The pressure distribution calculation unit 102 is configured to have the function of calculating the in-plane pressure distribution in the fuel cell cell 11 based on the voltage value of the pressure sensor 12a described above.

[0042] The pressure distribution correction unit 103 is configured to correct the in-plane pressure distribution measured before inflow based on the pressure change associated with the supply of fluid to the fuel cell stack 10. Examples of fluids 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 flowing in from the cooling water source 25.

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

[0044] The display control unit 105 performs processing to display various information, such as the water content distribution and degradation status of the fuel cell stack FC, via a display device PD including a known in-vehicle speaker SP or display DP. The display control unit 105 may also display the above-mentioned information to the occupants via an in-vehicle display device DD, or it may control the display by accessing an external terminal such as a smartphone carried by the occupants.

[0045] <Method for adjusting moisture content in fuel cell stacks> Next, with reference to Figure 7, a method for adjusting the moisture content in the fuel cell stack 10, which can be executed by the control device 100 in this embodiment, will be described. This moisture adjustment method may also be used as an algorithm in a computer-readable program. Such a program with an algorithm can be distributed, for example, via a known network for download to fuel cell vehicles (FCVs), or distributed in the form of a recording medium. The following explanation will use, for example, the scenario where a user starts up the system of a fuel cell vehicle (FCV) and begins driving.

[0046] First, in step 1, the control device 100 determines whether the fuel cell stack 10 has started up after the fuel cell vehicle (FCV) system 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 driven stably.

[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 cell 11. More specifically, the piezo voltage measurement unit 101 of the control device 100 detects the voltage values ​​of the multiple pressure sensors 12a on the pressure distribution measurement plate 12 via the voltage detection sensor SR5 described above.

[0048] At this time, the piezo voltage measurement unit 101 can determine, for example, that if the voltage value of the pressure sensor 12a at any point is higher than a predetermined reference value, it will be set to "High (H)", while if it is lower than the predetermined reference value, it will be set to "Low (L)". This makes it possible to calculate the pressure distribution based on the detected values ​​of each pressure sensor 12a within the pressure distribution measurement plate 12, as shown in Figure 8.

[0049] In this embodiment, the pressure distribution described above is detected based on whether it is high or low relative to a predetermined reference value, but this disclosure is not limited to this form. For example, instead of the above, the piezo voltage measurement unit 101 may calculate the pressure distribution using the voltage values ​​detected from the multiple pressure sensors 12a as they are, or it 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] Then, after measuring the uncorrected 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 can be performed in the fuel cell cell 11.

[0051] In step 3, the control device 100 may correct the in-plane pressure distribution measured before the inflow of the fluid based on the pressure change associated with the supply of the fluid to the fuel cell stack 10. At this time, the pressure change in the separator flow path of the fuel cell cell 11 can be calculated as follows. That is, first, as a prerequisite for calculating the above-mentioned pressure change, we assume that the fuel cell stack 10 is operating under the following five conditions. (Condition 1) The temperature inside the separator is kept constant. (Condition 2) The flow rate of gas permeating the electrolyte membrane is negligible and therefore can be ignored. (Condition 3) All water generated by the reaction in the fuel cell cell 11 is discharged as a gas. (Condition 4) According to the ideal gas law, the pressure is proportional to the number of gas molecules. (Condition 5) The current density generated in the fuel cell cell 11 by power generation is assumed to be constant.

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

[0053] TIFF0007911081000001.tif22144

[0054] Using Equation 1 above, the number of gas molecules at position x along the flow direction of the separator can be calculated, and the pressure value at position x can be calculated based on the above-mentioned ideal gas law. The pressure changes associated with the inflow of hydrogen gas and cooling water can also be calculated in the same manner as above. This allows for the calculation of the pressure changes caused by the inflow of fluid into the fuel cell cell 11 (separator). The pressure changes associated with the fluid supply to the fuel cell stack 10 may be calculated using other known 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 inflow, as illustrated in Figure 9, based on the pressure change associated with the start of fluid supply to the fuel cell 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 cell 11, which corresponds to the in-plane pressure distribution calculated in steps 2 and 3. More specifically, the control device 100 calculates the water content distribution in the in-plane direction of the fuel cell cell 11 based on information (pressure-water content characteristic information) that defines the relationship between water content and pressure values ​​that has been held in advance.

[0057] The pressure-water content characteristic information described above can be calculated in advance through experiments or simulations. Similarly, the appropriate water content range (target water content range) when the fuel cell cell 11 is operating (generating power) according to predetermined specifications can also be calculated in advance through experiments or simulations.

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

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

[0060] As an example, Figure 10(a) shows the change in water content Q when the temperature of the cooling water flowing into the fuel cell cell 11 is adjusted. In Figures 10(a) to (c), the horizontal axis represents the distance D from the cathode inlet to the cathode outlet of the fuel cell cell 11, with the cathode inlet as the origin, and the vertical axis represents the water content Q. In other words, as can be seen from Figure 10(a), when the temperature of the cooling water flowing into the fuel cell cell 11 is lowered, the state shown by the solid line can be shifted parallel to the upper side (i.e., in the direction of increasing water content). Similarly, as shown in Figure 10(a), when the temperature of the cooling water flowing into the fuel cell cell 11 is raised, the state shown by the solid line can be shifted parallel to the lower side (i.e., in the direction of decreasing water content). In this way, the control device 100 can uniformly increase or decrease the amount of water in the fuel cell cell 11 from the cathode inlet to the outlet by increasing or decreasing the temperature of the cooling water flowing into the fuel cell cell 11.

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

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

[0063] Similarly, the control device 100 can increase or decrease the amount of water contained in the fuel cell 11 from the 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 within the target water content range by adjusting at least one of the following: the flow rate and temperature of the cooling water flowing into the fuel cell 11, the flow rate of the intake air, and the rotation speed of the circulation pump 24 that supplies cooling water to the fuel cell 11.

[0064] After adjusting the moisture content distribution as described above in step 6, the control device 100 determines in the following step 7 whether the system has turned OFF, such as when the fuel cell vehicle (FCV) has arrived at its destination. If the system has turned OFF in step 7, the control device 100 completes the moisture content adjustment method of this embodiment as described above. On the other hand, if the system has not turned OFF in step 7, the control device 100 proceeds to step 1 and repeats the process described above.

[0065] According to the control device 100 and the moisture content adjustment method in the fuel cell stack of this embodiment described above, by detecting the pressure distribution in the in-plane direction using a pressure distribution measuring plate 12 positioned in a location where the impact on power generation of the fuel cell cell 11 is suppressed, it is possible to improve the durability of the pressure distribution measuring plate and the reliability of the measurement, and to calculate the moisture content distribution of the fuel cell cell.

[0066] <Computer programs, recording media> Furthermore, the computer program that implements the measurement of the in-plane pressure distribution in the fuel cell and the subsequent moisture content adjustment method by the control device 100 described above may cause one or more processors to execute a process (algorithm) that includes measuring the in-plane pressure distribution via a pressure distribution measuring plate interposed between the end plate and the current collector plate of the fuel cell stack, and calculating the moisture content distribution in the in-plane direction of the fuel cell based on the measured in-plane pressure distribution.

[0067] Furthermore, the computer program that implements the above-described functions of the control device 100 can, in addition to the algorithm described above, calculate the water content distribution in the in-plane direction of the fuel cell cell corresponding to the in-plane pressure distribution based on pre-stored pressure-water content characteristic information. In addition, the computer program that implements the above-described functions of the control device 100 can, in addition to the algorithm described above, correct the in-plane pressure distribution measured before inflow based on the pressure change associated with the fluid supply to the fuel cell stack (inflow of air, hydrogen gas, or cooling water). Furthermore, the computer program that implements the above-described functions of the control device 100 can, in addition to the algorithm described above, adjust at least one of the cooling water flow rate and temperature, the intake air flow rate, and the rotation speed of the circulation pump so that the water content at each point in the in-plane direction falls within the target water content range, based on the calculated water content distribution in the in-plane direction.

[0068] Furthermore, such computer programs may be stored in a form that is known, for example, the aforementioned recording medium, or they may be downloaded to a fuel cell vehicle (FCV) from a known server such as a cloud.

[0069] While preferred embodiments of the present disclosure have been described in detail above with reference to the attached drawings, the technology of the present disclosure is not limited to such examples. It is clear to any person with ordinary skill in the art to which the present disclosure belongs that various modifications or alterations may be conceived within the scope of the technical idea set forth in the claims, and these will naturally also be understood to fall within the technical scope of the present disclosure. [Explanation of Symbols]

[0070] 10 Fuel Cell Stacks 11 fuel cell cells 12 Pressure distribution measuring plate 13 End Plates 14 Current collector plate 15 Insulating board 20 Vehicle drive control system 100 Control device 101 Piezoelectric voltage measurement unit 102 Pressure distribution calculation unit 103 Pressure distribution correction unit 104 Pressure distribution adjustment unit 105 Display Control Unit FCV fuel cell vehicle

Claims

1. A fuel cell stack comprising multiple fuel cell cells stacked on top of each other, with a pressure distribution measuring plate capable of measuring the in-plane pressure distribution of the fuel cell cells interposed between the end plate and the current collector plate, A control device that calculates the water content distribution in the in-plane direction of the fuel cell based on the above in-plane pressure distribution, Includes, The fuel cell stack has an insulating plate on the outside of the current collector plate, The pressure distribution measuring plate is interposed between the current collector plate and the insulating plate and comprises a plurality of pressure sensors arranged in a grid pattern corresponding to the electrode regions of the stacked fuel cell cells. The control device calculates the water content distribution in the in-plane direction of the fuel cell cell, corresponding to the in-plane pressure distribution in the electrode region, based on the pressure-water content characteristic information that has been stored in advance, obtained via the plurality of pressure sensors. Fuel cell car.

2. The above control device is Before starting the supply of fluids including hydrogen gas, air, and cooling water to the fuel cell stack, the uncorrected pressure distribution in the in-plane direction of the fuel cell cell is measured based on the detection values ​​of the plurality of pressure sensors. The pressure change in the fuel cell accompanying the start of the fluid supply is calculated based on the change in the number of gas molecules corresponding to the position from the inlet to the outlet of the flow path through which the hydrogen gas or air flows, and the uncorrected pressure distribution is corrected based on the calculated pressure change. The water content distribution in the in-plane direction of the fuel cell cell corresponding to the corrected in-plane pressure distribution is calculated. The fuel cell vehicle according to claim 1.

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

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