JP6268493B2 - Fuel cell running-in system - Google Patents

Description

  The present invention relates to a fuel cell running-in system.

  A fuel cell supplies a fuel gas (a gas mainly containing hydrogen) and an oxidant gas (a gas mainly containing oxygen) to an anode side electrode and a cathode side electrode to cause an electrochemical reaction. It is a system for obtaining energy.

  For example, in a polymer electrolyte fuel cell, an electrolyte membrane / electrode structure (MEA) provided with an anode electrode and a cathode electrode on both sides of an electrolyte membrane made of a polymer ion exchange membrane is sandwiched by separators. A cell (hereinafter also referred to as a cell) is provided. This type of cell is normally used as a fuel cell stack mounted on a vehicle such as an automobile, for example, by stacking a predetermined number of electrolyte membrane / electrode structures and separators.

  In this type of polymer electrolyte fuel cell, the initial power generation performance is low because the water content of the electrolyte membrane immediately after assembly is not sufficient. Therefore, in order to draw out a desired power generation performance after assembling the fuel cell, a preliminary operation (running operation) called an aging operation of the fuel cell is usually performed. Note that the running-in operation includes allowing the cell performance to exhibit a desired capability by generating power after assembling the fuel cell.

  As this leveling operation, for example, a technique described in Patent Document 1 below is known. Patent Document 1 below discloses a technique for determining the end of a running-in operation after a lapse of a predetermined time.

JP 2007-066666 A

  By the way, fuel cells are subject to differences in cell specifications (platinum amount, type of electrolyte membrane, type of ionomer, type of gas diffusion layer, separator flow path, etc.) and individual differences (such as manufacturing variations). Normally, a difference in time required for the leveling operation is caused by each fuel cell. However, in the prior art, there was no method for measuring the time required for the leveling operation according to the cell specifications in advance, so as a result of specifying the time for the leveling operation with a margin (in terms of safety factor), There was a wasteful cost due to the extra power generation. As described above, there is still a problem to be solved in the conventional technique, and it is necessary to measure the time required for the leveling operation (the degree of completion of the leveling operation).

  The present invention has been made in view of such problems, and an object of the present invention is to provide a fuel cell running-in system capable of determining the degree of completion of a running-in operation.

  In order to solve the above-described problem, a running-in system for a fuel cell according to the present invention includes a supply means for supplying a humidified gas to the fuel cell, and measures the amount of moisture contained in the humidified gas supplied to the fuel cell. First measuring means, second measuring means for measuring the amount of water contained in the gas discharged from the fuel cell, and the amount of water measured by the first measuring means as X1, the second When the moisture content measured by the measurement means is defined as X2, the determination means determines that the fuel cell running-in operation is completed when X2 / X1 is a predetermined value.

  In the fuel cell running-in system according to the present invention, based on the amount of water contained in the gas supplied to the fuel cell (inlet water vapor amount) and the amount of water contained in the gas discharged from the fuel cell (outlet water vapor amount). Determine the completion of the break-in operation. In the past, since the leveling operation was performed with a margin (seeing the safety factor) in consideration of fluctuations in the leveling operation time due to differences in cell specifications and individual differences, power generation was performed even after the leveling operation was completed. There was a wasteful cost of continuing. On the other hand, in the present invention, the completion of the leveling operation is determined based on the inlet water vapor amount and the outlet water vapor amount, and power generation can be stopped as soon as the leveling operation is completed, thereby suppressing wasteful cost consumption. It becomes possible.

  The fuel cell run-in operation system according to the present invention includes: a discharge load means for supplying a current to the fuel cell when supplying the humidified gas; Calculating means for calculating the amount of water produced internally, wherein the determination means defines the fuel quantity when X2 / (X1 + X3) is a predetermined value when the calculated water quantity is defined as X3. It is also preferable to determine that the battery run-in has been completed.

  In this preferred embodiment, when the humidified gas is supplied to the fuel cell, a current is passed from the discharge load means to the fuel cell to determine whether the running operation is completed. As a result, the degree of completion of the leveling operation can be determined in consideration of the amount of generated water caused by flowing current.

  Further, in the fuel cell running-in system according to the present invention, the determining means determines that the test is in progress when X1 is greater than X2, and determines that the electrode is being dried when X2 is greater than X1. It is also preferable to determine.

  Further, in the fuel cell running-in system according to the present invention, the determination means determines that the leveling is in progress when the sum of the X1 and the X3 is larger than the X2, and the X2 is determined as the X1 and the X1. It is also preferable to determine that the electrode is being dried when greater than the sum of X3.

  ADVANTAGE OF THE INVENTION According to this invention, the leveling operation system of the fuel cell which can determine the completion degree of leveling operation can be provided.

It is a mimetic diagram showing a schematic structure of a running-in system of a fuel cell in a 1st embodiment of the present invention. It is a flowchart which shows the flow of an example of the leveling determination process of the fuel cell using the leveling operation system of the fuel cell shown in FIG. It is a figure for demonstrating the method of calculating a dew point from water weight. It is a figure for demonstrating the method of calculating a dew point from water weight. It is a graph which shows the relationship between water vapor pressure and a dew point. It is a schematic diagram which shows schematic structure of the leveling operation system of the fuel cell in 2nd Embodiment of this invention. It is a flowchart which shows the flow of an example of the leveling determination process of the fuel cell using the leveling operation system of the fuel cell shown in FIG.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The present invention is illustrated by the following preferred embodiments, but can be modified in many ways without departing from the scope of the present invention, and other embodiments other than this embodiment can be utilized. . Accordingly, all modifications within the scope of the present invention are included in the claims.

  As will be described below, the present embodiment is characterized by calculating the degree of completion of the leveling operation, but the background for the use of an index (leveling completion level) to be described later is as follows. It is mentioned. Specifically, while investigating what correlates with the completion of the leveling operation, the present inventors stopped raising the cell performance and the state in which the moisture was sufficiently distributed in the fuel cell stack (≈activity We obtained knowledge that there is a correlation in timing). Therefore, the present inventors have found that an index (degree of completion) to be described later is used to represent a state where moisture has sufficiently spread in the fuel cell stack.

  First, the configuration of the fuel cell running-in system according to the first embodiment of the present invention will be described. FIG. 1 is a schematic diagram illustrating a configuration of a break-in operation system. The running-in operation system is a system used for running the fuel cell.

  The leveling operation system 100a includes, in order from the upstream side, gas supply means 10a and 10b, mass flow controllers MFCa and MFCb, bubblers 20a and 20b, inlet-side dewpoint meters 30a and 30b, bypass pipes 210a and 210b, fuel A battery stack 2 (hereinafter referred to as a fuel cell 2), vaporizers 70a and 70b, outlet dew point meters 40a and 40b, drain pots 50a and 50b, and pipes 110a, 110b, 111a, and 111b connecting them. .

  The fuel cell 2 has a stack structure in which a plurality of single cells (in which electrodes having a structure such as a porous membrane capable of diffusing gas are formed on both surfaces of an electrolyte membrane) are stacked. In FIG. 1, for convenience of explanation, only the structure of a single cell having an anode electrode (hydrogen electrode) 2 a and a cathode electrode (air electrode) 2 b is shown as the fuel cell 2.

  The gas supply means 10a and 10b include an anode side gas supply means 10a and a cathode side gas supply means 10b. The anode-side gas supply means 10 a is a device for supplying hydrogen (fuel gas) to the anode electrode 2 a via a pipe 110 a connected to the anode electrode 2 a of the fuel cell 2. The cathode side gas supply means 10b is a device for supplying oxygen (oxidizing gas) to the cathode electrode 2b of the fuel cell 2 via a pipe 110b connected to the cathode electrode 2b of the fuel cell 2. The fuel gas and the oxidizing gas are supplied from the gas supply means 10a and 10b to the anode 2a and the cathode 2b of the fuel cell 2, respectively, so that the fuel cell 2 generates electric power and generates electric power.

  The bypass pipes 210a and 210b are flow paths for bypassing the fuel cell 2, and include an anode-side bypass pipe 210a and a cathode-side bypass pipe 210b. The bypass pipe 210a on the anode side is a flow path for bypassing the anode electrode 2a of the fuel cell 2, and a pipe 110a connected to the upstream side of the anode electrode 2a (left side with respect to the fuel cell 2 in FIG. 1) and In addition, the flow path communicates with a pipe 111a connected to the downstream side of the anode 2a (the right side with respect to the fuel cell 2 in FIG. 1). For this reason, the gas flowing in the pipe 110a passes through the bypass pipe 210a and flows into the pipe 111a. In other words, the gas flowing in the pipe 110a bypasses the fuel cell 2 and flows into the pipe 111a. The bypass pipe 210b on the cathode side is a flow path for bypassing the cathode electrode 2b of the fuel cell 2, and a pipe 110b connected to the upstream side of the cathode electrode 2b (left side with respect to the fuel cell 2 in FIG. 1) This is a flow path that communicates with a pipe 111b connected to the downstream side of the cathode 2b (on the right side of the fuel cell 2 in FIG. 1). For this reason, the gas flowing in the pipe 110b passes through the bypass pipe 210b and flows into the pipe 111b. In other words, the gas flowing in the pipe 110b bypasses the fuel cell 2 and flows into the pipe 111b.

  The mass flow controllers MFCa and MFCb are devices that adjust the flow rate of the gas flowing in the pipe 110a and the pipe 110b, respectively. The mass flow controller MFCa is disposed in the pipe 110 a and adjusts the flow rate of the fuel gas supplied to the anode electrode 2 a of the fuel cell 2. The mass flow controller MFCb is disposed in the pipe 110 b and adjusts the flow rate of the oxidizing gas supplied to the cathode electrode 2 b of the fuel cell 2.

  The bubblers 20a and 20b humidify the gas supplied from the gas supply means 10a and 10b, and supply the humidified gas to the fuel cell 2. The bubbler 20a is provided in the middle of the pipe 110a that connects the gas supply means 10a and the anode 2a of the fuel cell 2. The fuel gas supplied from the gas supply means 10a is humidified by passing through the bubbler 20a, and the humidified fuel gas is supplied to the anode 2a of the fuel cell 2. The bubbler 20b is provided in the middle of the pipe 110b connecting the gas supply means 10b and the cathode electrode 2b of the fuel cell 2. The oxidizing gas supplied from the gas supply means 10b is humidified by passing through the bubbler 20b, and the humidified oxidizing gas is supplied to the cathode 2b of the fuel cell 2. The temperature in the bubblers 20a and 20b is adjusted to a predetermined temperature by a heating means (not shown). The gas supply means 10a and 10b and the bubblers 20a and 20b described above correspond to the “supply means” in the present invention.

  The inlet side dew point meters 30a and 30b (first measuring means) are devices that are disposed on the inlet side (upstream side) of the fuel cell 2 and measure the dew points of the gas flowing in the pipes 110a and 110b. The inlet-side dew point meter 30a provided on the anode side is disposed in the pipe 110a between the bubbler 20a and the anode electrode 2a of the fuel cell 2, and measures the dew point of the fuel gas flowing in the pipe 110a. The inlet-side dew point meter 30b provided on the cathode side is disposed in the pipe 110b between the bubbler 20b and the cathode electrode 2b of the fuel cell 2, and measures the dew point of the oxidizing gas flowing in the pipe 110b. Measuring the dew point of gas means measuring the amount of moisture in the gas, so the inlet side dew point meters 30a and 30b can also be regarded as moisture meters for measuring the moisture in the gas. Therefore, the inlet side water vapor amount (inlet water vapor amount) of the fuel cell 2 can be measured by the inlet side dew point meters 30a and 30b. The measured inlet water vapor amount is used to calculate the degree of leveling completion described later.

  The vaporizers 70a and 70b are devices that are disposed on the outlet side (downstream side) of the fuel cell 2 and increase the temperature of the gas flowing in the pipes 111a and 111b. The vaporizer 70a provided on the anode side raises the temperature of the fuel gas flowing in the pipe 111a connected to the downstream side of the anode 2a of the fuel cell 2. The vaporizer 70b provided on the cathode side raises the temperature of the oxidizing gas flowing in the pipe 111b disposed on the downstream side of the cathode electrode 2b of the fuel cell 2. Thus, by raising the temperature of the gas flowing in the pipes 111a and 111b by the vaporizers 70a and 70b, it becomes possible to measure the total amount of water vapor measured by the outlet dew point meters 40a and 40b described later. . Note that the temperature of the gas raised by the vaporizers 70 a and 70 b is appropriately adjusted by the control device 400. In this embodiment, vaporizers 70a and 70b are provided. However, if the vaporizers 70a and 70b have a function of increasing the temperature of the gas flowing in the pipes 111a and 111b, other devices (for example, heaters) are installed. Is also possible.

  The outlet side dew point meters 40a and 40b (second measuring means) are devices that are arranged on the outlet side (downstream side) of the fuel cell 2 and measure the dew points of the gas flowing in the pipes 110a and 110b. The anode-side outlet-side dew point meter 40a is provided in a pipe 111a connected between the vaporizer 70a and the drain pot 50a, and measures the dew point of the gas discharged from the anode electrode 2a. The cathode-side outlet dew point meter 40b is provided in the pipe 111b connected between the vaporizer 70b and the drain pot 50b, and measures the dew point of the gas discharged from the cathode electrode 2b. Measuring the dew point of gas means measuring the amount of moisture in the gas, so the outlet side dew point meters 40a and 40b can also be regarded as moisture meters for measuring the moisture in the gas. Therefore, the outlet side water vapor amount (outlet water vapor amount) of the fuel cell 2 can be measured by the outlet side dew point meters 40a and 40b. The measured outlet water vapor amount is used to calculate the degree of leveling completion described later.

  The drain pots 50 a and 50 b are containers for storing water collected from the gas discharged from the fuel cell 2 and provided downstream of the outlet side dew point meters 40 a and 40 b. Specifically, a cooling unit (not shown) is provided on the upstream side of the drain pots 50a and 50b, and the cooling unit cools the gas flowing in the pipes 111a and 111b, thereby moisture contained in the gas. The condensed water can be collected by the drain pots 50a and 50b. The drain pot 50a on the anode side collects water condensed from the gas discharged from the anode 2a of the fuel cell 2. The drain pot 50b on the cathode side collects water condensed from the gas discharged from the cathode electrode 2b of the fuel cell 2.

  The control device 400 is configured as a computer having a CPU that executes logical operations, a ROM, and a RAM. In the present embodiment, the control device 400 has a function of calculating a reference dew point from the water weight of the drain pots 50a and 50b. Further, the control device 400 has a function of correcting the temperatures of the bubblers 20a and 20b, the inlet side dew point meters 30a and 30b, and the outlet side dew point meters 40a and 40b from the calculated reference dew point (a function for performing zero point adjustment). Further, the control device 400 has a function of calculating a degree of leveling completion, which will be described later, based on the measured values of the inlet side dew point meters 30a and 30b and the outlet side dew point meters 40a and 40b. Further, the control device 400 calculates the amount of generated water from the load current value flowing from the discharge load device (see FIG. 6), the generated water amount, the measured values of the inlet side dew point meters 30a and 30b, and the outlet side dew point meters 40a and 40b. Based on the measured value, a function for calculating a smoothing completion degree, which will be described later, is provided.

<Fuel cell leveling process>
A fuel cell leveling determination process using the fuel cell leveling operation system 100a shown in FIG. 1 will be described. FIG. 2 is a flowchart illustrating an example of a fuel cell leveling determination process.

(Step S110)
The humidified gas supplied from the gas supply means 10a and 10b and humidified through the bubblers 20a and 20b is switched to a line passing through the bypass pipes 210a and 210b so as to bypass the fuel cell 2 (step S110). Line switching is performed on the anode side and cathode side as follows. That is, on the anode side, the humidified gas supplied from the gas supply means 10 a and humidified through the bubbler 20 a is switched to a line passing through the bypass pipe 210 a so as to bypass the anode electrode 2 a of the fuel cell 2. On the cathode side, the humidified gas supplied from the gas supply means 10 b and humidified through the bubbler 20 b is switched to a line passing through the bypass pipe 210 b so as to bypass the cathode electrode 2 b of the fuel cell 2. As a result, the gas flowing in the anode-side piping 110a is not supplied to the fuel cell 2, but flows in the piping 111a connected to the downstream side of the fuel cell 2 via the bypass pipe 210a, and in the drain pot 50a. Collected. Further, the gas flowing in the cathode-side piping 110b is not supplied to the fuel cell 2, but flows in the piping 111b connected to the downstream side of the fuel cell 2 via the bypass pipe 210b, and the drain pot 50b. It is collected at. Note that the switching to the line passing through the bypass pipe 210a on the anode side is performed, for example, by the control device 400 controlling the opening degree of a switching valve (not shown) disposed at the connection portion between the bypass pipe 210a and the pipes 110a and 111b. Is done. In addition, the switching to the line passing through the cathode side bypass pipe 210b is performed, for example, by the control device 400 controlling the opening degree of a switching valve (not shown) provided at a connection portion between the bypass pipe 210b and the pipes 110b and 111b. Is done.

(Step S120)
From the water weight collected in the drain pots 50a and 50b, the control device 400 calculates a reference dew point (step S120). A reference dew point calculation method by the control device 400 will be described with reference to FIGS.

  FIG. 3 is a diagram for explaining a method of calculating the reference dew point, and schematically shows a system in which moisture contained in the humidified gas that has been humidified through the bubbler 20 is collected in the drain pot 50. It is. In FIG. 3, for convenience of explanation, illustration of the fuel cell 2 and the bypass pipes 210a and 210b shown in FIG. 1 is omitted. 3, the gas supply means 10a and 10b, the mass flow controllers MFCa and MFCb, the bubblers 20a and 20b, and the drain pots 50a and 50b shown in FIG. 1 are collectively referred to as the gas supply means 10, the mass flow controller MFC, and the bubbler, respectively. 20 and a drain pot 50 are shown.

  As shown in FIG. 3, the humidified gas supplied from the gas supply means 10 and humidified through the bubbler 20 is cooled by the cooling unit 51, part of which is condensed, and is collected in the drain pot 50. . The gas that has not been collected in the drain pot 50 is exhausted to the outside.

The relationship between the humidified gas supplied from the bubbler 20, the partial pressure of water vapor, and the flow rate is as shown in FIG. Specifically, the absolute pressure (total supply pressure) at the time of gas supply supplied from the bubbler 20 is a, the gas supply flow rate from the gas supply means 10 is b, and the water vapor flow rate that is drain water in the drain pot 50 ( The amount of water vapor per unit time calculated from the increase in drain water weight is c, the flow rate of the discharged water vapor is d, the water vapor partial pressure of the bubbler 20 is x, and the water vapor partial pressure is y, the water vapor of the bubbler 20 The partial pressure x can be calculated by the following formula (1). The exhausted water vapor partial pressure y is obtained from the temperature of the cooling unit 51 and the water vapor pressure curve of FIG. For each flow rate (b, c, d), for example, values (b (NmL / min), c (NmL / min), d (NmL / min)) represented by normal flow rates are used.
x = (a × c) / (b + c + d) + y (1)
Note that d = y × (b + c) / (a−y).

  The dew point temperature is calculated based on the water vapor pressure curve shown in FIG. 5 from the value of the water vapor partial pressure x of the bubbler calculated by the above equation (1). For example, when the value of the water vapor partial pressure x is calculated as P1 (kPa) by the above equation (1), the dew point is calculated as T1 (° C. td) based on the water vapor pressure curve of FIG.

  The reference dew point is accurately calculated by the above-described reference dew point calculation method. However, when performing the subsequent steps, if there is a more convenient and accurate reference dew point measuring means, the method is not limited to the above-described reference dew point calculation method. May be.

(Step S130)
Based on the reference dew point calculated in step S120, the control device 400 corrects the temperatures of the bubblers 20a and 20b, the inlet side dew point meters 30a and 30b, and the outlet side dew point meters 40a and 40b. In other words, the control device 400 performs zero adjustment of the bubbler temperature, the inlet side dew point, and the outlet side dew point.

  The purpose of adjusting the bubbler temperature to zero is as follows. Ideally, it is desirable that the bubbler temperature and the reference dew point coincide with each other, but actually, the bubbler temperature> the reference dew point is often satisfied. This difference is obtained first, and the bubbler temperature is corrected (so-called zero point adjustment) using the difference, thereby enabling accurate derivation of the degree of completion of the break-in operation (described later). For example, when the bubbler temperature is 60 ° C. and the reference dew point is 59 ° C., the bubbler temperature is set to 61 ° C. (zero adjustment). This makes it possible to accurately determine the degree of completion of the leveling operation at a dew point of 60 ° C. However, when absolute accuracy of the dew point is required, feedback control may be performed to adjust the reference dew point to 60 ° C. When the dew point meter at the inlet / outlet (inlet side dew point meter 30a, 30b, outlet side dew point meter 40a, 40b) is better than the dew point accuracy, the temperature of all dew point meters should be equal (for example, (59.5 ° C. or the like) may be corrected. If the absolute accuracy of the dew point is not required, the dew point meter may be corrected at 59 ° C. and the bubbler temperature may be increased by 1 ° C. to start the judgment of the degree of completion of the leveling operation. As described above, when the dew point accuracy is required for zero point adjustment, feedback control may be performed by the control device 400 to correct the reference dew point. When only the dew point relative accuracy is required, the bubbler temperature is adjusted. Only one correction may be performed.

(Step S140)
Next, the fuel cell 2 is switched to a line through which gas passes (step S140). Specifically, on the anode side, the line is switched so that the humidified gas supplied from the gas supply means 10 a and humidified through the bubbler 20 a is supplied to the anode 2 a of the fuel cell 2. On the cathode side, the lines are switched so that the humidified gas supplied from the gas supply means 10 b and passed through the bubbler 20 b is supplied to the cathode electrode 2 b of the fuel cell 2. In addition, such line switching is appropriately provided in a switching valve (not shown) appropriately provided in the pipes 110a and 111a connected to the anode electrode 2a and in the pipes 110b and 111b connected to the cathode electrode 2b. The control valve 400 adjusts the opening of the switching valve (not shown).

(Step S150)
Next, the humidified gas supplied from the gas supply means 10a and 10b and humidified through the bubblers 20a and 20b is supplied to the fuel cell 2 (step S150). The humidified fuel gas flowing through the anode side piping 110 a is supplied to the anode 2 a of the fuel cell 2. The humidified oxidizing gas flowing in the cathode side piping 110 b is supplied to the cathode electrode 2 b of the fuel cell 2.

(Step S160)
Next, the condensed water contained in the gas discharged from the fuel cell 2 is vaporized by the vaporizers 70a and 70b (step S160). Condensed water contained in the gas discharged from the anode 2a is vaporized by the vaporizer 70a. Condensed water contained in the gas discharged from the cathode electrode 2b is vaporized by the vaporizer 70b. The gas vaporized by the vaporizers 70a and 70b flows through the pipes 111a and 111b through the outlet side dew point meters 40a and 40b.

(Step S170)
Next, the dew points of the gas flowing in the pipes 110a and 110b connected to the upstream side of the fuel cell 2 are measured by the inlet side dew point meters 30a and 30b, and the downstream side of the fuel cell 2 is measured by the outlet side dew point meters 40a and 40b. The dew point of the gas flowing through the pipes 111a and 111b connected to the side is measured (step S170). As described above, measuring the dew point of gas means measuring the amount of water in the gas, so it is included in the gas by the inlet side dew point meters 30a and 30b and the outlet side dew point meters 40a and 40b. It is possible to measure the amount of water (the amount of water vapor). The measured inlet-side water vapor amount (inlet water vapor amount) of the fuel cell 2 and outlet-side water vapor amount (outlet water vapor amount) of the fuel cell 2 are used for the following calculation of the degree of smoothing.

(Step S180)
Next, based on the inlet water vapor amount (X1) and the outlet water vapor amount (X2), the control device 400 calculates the degree of completion (leveling completion) of the leveling operation of the fuel cell 2 by the following equation (2) (step) S180).
Completion level = (outlet water vapor amount (X2)) / (inlet water vapor amount (X1)) (2)

  When it is determined by the control device 400 that the value calculated by the above equation (2) has reached a predetermined value, in other words, it is determined by the control device 400 that the water balance during power generation of the fuel cell 2 has reached the predetermined value. Then, the control device 400 ends the leveling operation of the fuel cell 2 (“leveling complete”). The predetermined value is preferably set to 100%, for example, but can be appropriately set to a value near 100% such as 95%.

  In the case where the water balance during power generation of the fuel cell 2 is positive, that is, the control device 400 determines that the sum of the inlet water vapor amount and the generated water amount is larger than the outlet water vapor amount (inlet water vapor amount (X1)> outlet water vapor amount (X2). ) Is defined as “in the middle of leveling”. In this case, the humidified gas supplied to the fuel cell 2 is absorbed by the anode 2a and the cathode 2b of the fuel cell 2.

  When the water balance during power generation of the fuel cell 2 is negative, that is, the control device 400 has an outlet water vapor amount larger than the inlet water vapor amount (inlet water vapor amount (X1) <outlet water vapor amount (X2)). If determined, it is defined as “electrode drying”. If this state during electrode drying continues, it means that dry-up and, consequently, power generation of the fuel cell is stopped.

  When the steps S110 to S180 are obtained and the leveling completion degree expressed by the above formula (2) reaches a predetermined value, the leveling determination step of the fuel cell 2 is completed.

  As described above, in the break-in operation system according to the present embodiment, the amount of water contained in the gas supplied to the fuel cell (inlet water vapor amount) and the amount of water contained in the gas discharged from the fuel cell (outlet water vapor amount). Based on the above, it is determined whether or not the break-in operation has been completed. Conventionally, the leveling operation is performed with a margin (in view of the safety factor) in consideration of the time variation of the leveling operation due to differences in cell specifications and individual differences. For this reason, conventionally, wasteful costs have been generated by continuing power generation even after the completion of the leveling operation.In the present invention, however, the completion of the leveling operation is determined based on the inlet water vapor amount and the outlet water vapor amount. Since power generation can be stopped as soon as the break-in operation is completed, wasteful cost consumption can be suppressed.

  Moreover, in this embodiment, before supplying the humidified gas and determining the degree of completion of the running-in operation, a reference dew point is calculated based on the weight of water collected in the drain pots 50a and 50b, and based on the reference dew point, The inlet side dew point meters 30a and 30b, the outlet side dew point meters 40a and 40b, and the zero point of the bubbler temperature are adjusted. The dew point meters (inlet side dew point meters 30a and 30b, outlet side dew point meters 40a and 40b) generally have machine differences and changes over time, but are determined from the weight of water collected in the drain pots 50a and 50b. By adjusting the zero point of the dew point meter based on the reference dew point, the relative accuracy of each dew point meter can be increased. As a result, it is possible to accurately determine the smoothing degree calculated based on the inlet water vapor amount and the outlet water vapor amount.

  Next, the configuration of the fuel cell break-in operation system according to the second embodiment will be described. FIG. 6 is a schematic diagram illustrating a schematic configuration of a fuel cell break-in operation system according to the second embodiment. The leveling operation system 100b shown in FIG. 6 is different from the configuration of the leveling operation system 100a shown in FIG. 1 in that a discharge load device 90 (discharge load means) is provided. Other configurations and functions Is equivalent to the leveling operation system 100a shown in FIG. Therefore, the description of the same part as the leveling operation system 100a shown in FIG. 1 is omitted.

The discharge load device 90 is a device for applying a load current to the fuel cell 2. The discharge load device 90 is connected to the anode electrode 2a and the cathode electrode 2b of the fuel cell 2 via the wiring 91, and allows a load current to flow through the anode electrode 2a and the cathode electrode 2b. The magnitude of the load current value (current value) supplied from the discharge load device 90 to the fuel cell 2 is controlled by the control device 400. By causing the load current to flow through the fuel cell 2, generated water is generated from the fuel cell 2, and the control device 400 can calculate the amount of generated water generated from the fuel cell 2 based on the magnitude of the load current value. It has become. The amount of generated water is calculated by calculating (current value) × (time) by the control device 400 based on the electrochemical reaction formula (1 / 2O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O).

  A fuel cell leveling determination process using the leveling operation system 100b shown in FIG. 6 will be described. FIG. 7 is a flowchart illustrating an example of a fuel cell leveling determination process according to the modification. Since steps S110 to S140 in FIG. 7 have the same contents as steps S110 to S140 described in FIG. 2, the same reference numerals are given and description thereof is omitted.

(Step S150b)
Humidified gas supply and discharge load are started to the fuel cell 2 (step S150b). The humidification gas is supplied by humidifying the gases supplied from the gas supply means 10a and 10b through the bubblers 20a and 20b, respectively. The discharge load is performed by flowing a current from the discharge load device 90 to the fuel cell 2 via the wiring 91.

(Step S160b)
Next, the dew condensation water contained in the gas discharged from the fuel cell 2 and the generated water generated from the fuel cell 2 are vaporized in the vaporizers 70 a and 70 b disposed on the downstream side of the fuel cell 2.

(Step S170b)
Next, the dew points (inlet dew points) of the gas flowing in the pipes 110a and 110b connected to the upstream side of the fuel cell 2 are measured by the inlet side dew point meters 30a and 30b, and the fuel is discharged by the outlet side dew point meters 40a and 40b. The dew point (exit dew point) of the gas flowing in the pipes 111a and 111b connected to the downstream side of the battery 2 is measured. The inlet-side dew point meter 30a and the outlet-side dew point meter 40a measure the gas dew point on the anode electrode 2a side. The inlet-side dew point meter 30b and the outlet-side dew point meter 40b measure the dew point of the gas on the cathode electrode 2b side. By measuring the dew point of the gas, it is possible to measure the amount of water in the gas. That is, the inlet-side dew point meter 30a, 30b can measure the inlet-side water vapor amount (inlet water vapor amount) of the fuel cell 2, and the outlet-side dew point meter 40a, 40b can measure the outlet-side water vapor amount (outlet) of the fuel cell 2. Water vapor amount) can be measured. In the present embodiment, the inlet dew point and the outlet dew point of each electrode are measured, and the control device 400 calculates the amount of generated water based on the current value (load current value) flowing from the discharge load device 90.

(Step S180b)
Next, based on the measured inlet water vapor amount (X1), outlet water vapor amount (X2), and the generated water amount (X3) calculated from the load current value, the control device 400 determines the degree of completion of the leveling operation of the fuel cell 2 ( The degree of completion) is calculated by the following equation (3).
Completion level = (outlet water vapor amount (X2)) / (inlet water vapor amount (X1) + product water amount (X3)) (3)
The generated water amount X3 is, for example, a value converted into normal (NL / min).

  When it is determined by the control device 400 that the value calculated by the above equation (3) has reached a predetermined value, in other words, when the water balance during power generation of the fuel cell 2 has reached a predetermined value, the fuel cell 2 End the break-in operation (“break-in”). The predetermined value for determining that the leveling is completed is preferably set to 100%, for example, but can be appropriately set to a value in the vicinity of 100% such as 95%.

  When the water balance during power generation of the fuel cell 2 is positive, that is, the sum of the inlet water vapor amount and the generated water amount is larger than the outlet water vapor amount by the control device 400 (inlet water vapor amount + product water amount> outlet water vapor amount). ) Is defined as “in the middle of leveling”. In this case, the humidified gas supplied to the fuel cell 2 is absorbed by the anode 2a and the cathode 2b of the fuel cell 2.

  When the water balance during power generation of the fuel cell 2 is negative, that is, the control apparatus 400 causes the outlet water vapor amount to be larger than the sum of the inlet water vapor amount and the generated water amount (inlet water vapor amount + generated water amount <outlet water vapor). If it is determined that the electrode is being dried, it is defined as “electrode drying”. If this state during electrode drying continues, it means that dry-up and, consequently, power generation of the fuel cell is stopped.

  The steps S110 to S180b are obtained, and the leveling determination step for the fuel cell 2 is completed.

  As described above, in the present embodiment, the humidification gas is supplied to the fuel cell 2 and simultaneously the load current is added to determine the level of completion of the fuel cell 2. As a result, it is possible to determine whether the leveling operation has been completed in consideration of the amount of water produced by the load current.

  In addition, as above-mentioned, this invention is not limited to the said embodiment, A various deformation | transformation is possible in the limit which does not change the summary. In addition, each element provided in each specific example, its arrangement, conditions, and the like are not limited to those illustrated, but can be changed as appropriate.

2: Fuel cell 10a, 10b: Gas supply means 20a, 20b: Bubbler 30a, 30b: Inlet dew point meter (first measuring means)
40a, 40b: outlet side dew point meter (second measuring means)
50a, 50b: Drain pots 70a, 70b: Vaporizer 90: Discharge load device (discharge load means)
100a, 100b: leveling operation systems 110a, 110b, 111a, 111b: piping 210a, 210b: bypass pipe 400: control device (determination means, calculation means)
MFCa, MFCb: Mass flow controller

Claims (4)

A running-in system for running-in a fuel cell,
Supply means for supplying humidified gas to the fuel cell;
First measuring means for measuring the amount of water contained in the humidified gas supplied to the fuel cell;
Second measuring means for measuring the amount of water contained in the gas discharged from the fuel cell;
If the moisture content measured by the first measurement means is defined as X1 and the moisture content measured by the second measurement means is defined as X2, if X2 / X1 is a predetermined value, Determining means for determining that the driving operation is completed;
The running-in system characterized by having. A discharge load means for supplying a current to the fuel cell when supplying the humidified gas;
Calculation means for calculating the amount of water produced inside the fuel cell based on the value of the current flowing from the discharge load means;
2. The determination means, when the calculated amount of generated water is defined as X3, determines that the leveling operation of the fuel cell is completed when X2 / (X1 + X3) is a predetermined value. The running-in system described in   2. The method according to claim 1, wherein when the X1 is larger than the X2, the determination unit determines that the test is in progress, and determines that the electrode is being dried when the X2 is greater than the X1. Driving system.   The determination means determines that the test is in progress when the sum of X1 and X3 is greater than X2, and determines that the electrode is being dried when X2 is greater than the sum of X1 and X3. The break-in operation system according to claim 2, wherein:

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