JP6124619B2 - Gas flow control device and gas flow control method - Google Patents

Description

  The present invention evaluates the power generation performance and durability of a fuel cell that generates electrical energy by an electrochemical reaction between an anode gas (for example, a fuel gas such as hydrogen) and a cathode gas (for example, an oxidant gas such as air or oxygen). A gas flow rate control device and a gas that are suitably employed in a fuel cell evaluation test system for performing a test and that can control the flow rate of gas when the unreacted gas discharged from the fuel cell during power generation is circulated and reused The present invention relates to a flow rate control method.

  A fuel cell is a power generation device that can continuously extract electric power by supplying and reacting a replenishable negative electrode active material and a positive electrode active material in a normal temperature or high temperature environment, and differs from a normal power generation system using a heat engine. In the course of conversion from chemical energy to electrical energy, it does not go through the form of heat energy or kinetic energy. Moreover, since the fuel cell does not depend on the Carnot efficiency specific to the heat engine, the power generation efficiency is high, and the noise and vibration are small without being greatly affected by the size of the system. For this reason, it is expected as an energy source used in various applications such as portable terminal devices such as notebook computers and mobile phones, automobiles, railways, and consumer / industrial cogeneration power plants.

  In developing a fuel cell that can be used as an energy source for various applications as described above, for example, a performance test and a durability test of the fuel cell are performed using an evaluation test apparatus disclosed in Patent Document 1 below. And comprehensive evaluation of fuel cells.

JP 2005-166601 A (Patent No. 4511162)

  By the way, in a fuel cell vehicle using a fuel cell as an energy source, an unreacted anode gas (for example, a fuel gas such as hydrogen) discharged from a fuel cell configured in a stack is circulated and reused without being exhausted. . In addition, even if the flow rate of the supplied anode gas is the same, the pressure loss varies depending on the fuel cell configuration such as the number of stacks, the structure of the membrane / electrode assembly (MEA), the structure of the separator, and the material. In addition, when operating a single fuel cell, the internal pressure loss fluctuates due to, for example, blockage of the flow path with water or swelling of the membrane, and the inlet pressure of the fuel cell during power generation varies with this fluctuation in pressure loss. The pressure difference between the outlet and the outlet pressure, the so-called differential pressure, also varies. For this reason, the differential pressure between the inlet pressure and the outlet pressure of the fuel cell accompanying the circulation of the unreacted anode gas is controlled, and as a result, the anode gas is adjusted to the flow rate of the performance evaluation condition desired by the user. It has been desired to provide an evaluation test apparatus that can perform a battery performance test.

  However, in the conventional fuel cell evaluation and test apparatus, all of the unreacted anode gas is exhausted without being circulated, so the fuel cell inlet pressure and the outlet pressure between the unreacted anode gas circulate. The anode gas could not be adjusted to the flow rate desired by the user by controlling the differential pressure, and the fuel cell evaluation test could not be performed while simulating actual vehicle operation at the test room level.

  Accordingly, the present invention has been made in view of the above problems, and provides a gas flow rate control device and a gas flow rate control method capable of controlling the flow rate of gas to the fuel cell accompanying the circulation of unreacted gas. It is the purpose.

In order to achieve the above object, a gas flow rate control device according to claim 1 is a fuel cell that controls the flow rate of a gas supplied to a fuel cell that generates electrical energy by an electrochemical reaction between an anode gas and a cathode gas. In the gas flow control device,
A fuel gas supply device for supplying gas to the fuel cell;
A loop-shaped circulation flow path returning from the outlet of the fuel cell toward the inlet is connected to the fuel gas supply device,
A pressure reducing valve in the loop and a pressure increasing pump are arranged in order from a position close to the inlet of the fuel cell,
A differential pressure gauge for measuring a differential pressure due to a pressure difference between an inlet pressure and an outlet pressure of the fuel cell in the circulation channel;
A measuring instrument for measuring the concentration of each gas composition of moisture, pressure, temperature, and gas components between the pressure reducing valve in the loop and the inlet of the fuel cell;
At the time of power generation of the fuel cell, a target set differential pressure is calculated based on a target set flow rate under performance evaluation conditions set in advance and a measurement result by the measuring instrument, and the differential pressure measured by the differential pressure gauge is calculated as the calculated target. And a controller for controlling opening and closing of the in-loop pressure reducing valve so as to approach the set differential pressure .

The gas flow rate control device according to claim 2 is the gas flow rate control device according to claim 1 ,
A pressure gauge that measures the pressure of the gas sucked into the booster pump through the circulation channel;
And a supply-side pressure reducing valve that is controlled to be opened and closed by the control unit according to the pressure measured by the pressure gauge.

Gas flow rate control method according to claim 3 wherein, there is provided a gas flow rate control method using the gas flow control device according to claim 1,
After starting the operation of the booster pump, the differential pressure measured by the differential pressure gauge is compared with the calculated target set differential pressure, and when the differential pressure measured by the differential pressure gauge does not reach the target set differential pressure, The method includes a step of controlling opening and closing of the pressure reducing valve in the loop so that the differential pressure measured by the differential pressure gauge approaches the target set differential pressure.

A gas flow rate control method according to claim 4 is a gas flow rate control method using the gas flow rate control device according to claim 2 ,
Measuring the pressure of the gas sucked into the booster pump through the circulation channel;
And controlling the opening and closing of the supply side pressure reducing valve when the measured pressure is equal to or lower than a preset minimum set pressure.

  ADVANTAGE OF THE INVENTION According to this invention, the gas flow volume supplied to a fuel cell can be adjusted to the flow volume of the performance evaluation conditions of the fuel cell which a user desires. Thereby, the evaluation test of the fuel cell can be performed at the mounting level of the fuel cell vehicle that circulates and reuses the unreacted gas without exhausting it.

It is a schematic block diagram which shows 1st Embodiment of the gas flow control apparatus which concerns on this invention. It is a flowchart which shows the processing content in 1st Embodiment of the gas flow control apparatus which concerns on this invention. It is a schematic block diagram which shows 2nd Embodiment of the gas flow control apparatus which concerns on this invention. It is a schematic block diagram which shows 3rd Embodiment of the gas flow control apparatus which concerns on this invention.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In addition, the present invention is not limited by this embodiment, and all other forms, examples, operation techniques, and the like that can be implemented by those skilled in the art based on this form are included in the scope of the present invention. .

  The gas flow rate control device according to the present invention is a power generation performance of a fuel cell that generates electric energy by an electrochemical reaction between an anode gas (for example, a fuel gas such as hydrogen) and a cathode gas (for example, an oxidant gas such as air or oxygen). And a fuel cell evaluation test system for performing an evaluation test such as durability and durability.

  In the gas flow rate control device according to the present invention, in particular, the gas flow rate when the unreacted gas (anode gas or cathode gas) discharged from the fuel cell during power generation is circulated and reused is determined as the inlet pressure of the fuel cell. And a function of adjusting by differential pressure control between the outlet pressure and the outlet pressure.

  In the present invention, the fuel cell as an evaluation test object is, for example, a polymer electrolyte fuel cell (PEFC), a phosphoric acid fuel cell (PAFC), a molten carbonate fuel cell (MCFC), or a solid oxide fuel cell. (SOFC), alkaline electrolyte fuel cell (AFC), biofuel cell and the like.

  As shown in FIGS. 1, 3 and 4, the fuel cell 2 has an anode (fuel electrode) 2a and a cathode (air electrode) 2b. An anode gas is supplied to the anode 2a and a cathode gas is supplied to the cathode 2b. Is supplied, the anode gas and the cathode gas cause an electrochemical reaction to generate electric power. The anode gas supplied to the anode 2a includes, for example, hydrogen gas, methane gas, propane gas, and the like. Here, a case where hydrogen gas is used as the anode gas will be described as an example.

  FIG. 1 shows a schematic configuration of a first embodiment of a gas flow rate control apparatus according to the present invention. As shown in FIG. 1, the gas flow control device 1 (1A) of the first embodiment is a gas for supplying hydrogen gas to a fuel cell 2 from a gas storage tank (not shown) via a supply-side pressure reducing valve 3. A supply device 3A is provided.

  The supply-side pressure reducing valve 3 is connected to a gas storage tank (not shown) by piping, and includes hydrogen gas necessary for power generation of the fuel cell 2 (including hydrogen gas in an idling state and hydrogen gas consumed by the power generation of the fuel cell 2). It has the inlet 3a for supplying as needed. The supply-side pressure reducing valve 3 is a valve that can adjust the pressure on the outlet 3b side, and the control unit 13 according to a comparison result between a target set pressure input from the operation unit 12 described later and the pressure by the pressure gauge 10. The opening / closing (opening degree) is controlled by. Thereby, the supply side pressure reducing valve 3 depressurizes the high-pressure hydrogen gas supplied from the gas supply device 3A to the inlet 3a, and maintains the outlet 3b side at a constant set pressure.

  A circulation passage 4 for reusing unreacted hydrogen gas discharged from the fuel cell 2 is formed on the outlet 3 b side of the supply side pressure reducing valve 3. The circulation channel 4 forms a closed loop so as to return from the outlet 2a2 of the anode 2a of the fuel cell 2 toward the inlet 2a1, as indicated by a thick black line (circulation direction: dotted arrow) in FIG. It is connected to the outlet 3b of the supply side pressure reducing valve 3 via the junction 4A.

  A flow meter 5, an in-loop pressure reducing valve 6, a buffer tank 7, and a booster pump 8 are arranged in this order from the position near the inlet 2 a 1 on the side of the inlet 2 a 1 of the anode 2 a of the fuel cell 2 in the circulation channel 4. ing. An inlet 9a of the back pressure valve 9 is connected to the outlet 2a2 of the anode 2a of the fuel cell 2 in the circulation channel 4, and a pressure gauge 10 is connected between the outlet 9b of the back pressure valve 9 and the inlet 8a of the booster pump 8. It is connected. Further, the gas flow control device 1A includes a differential pressure gauge 11 that measures a differential pressure between the inlet pressure and the outlet pressure of the anode 2a of the fuel cell 2, an operation unit 12 that includes an operation panel, and each valve (supply side pressure reduction). The control part 13 which controls opening and closing (opening degree) of the valve 3, the pressure reducing valve 6 in a loop, and the back pressure valve 9) is provided.

  The circulation flow path 4 includes a gas pressure increase flow path 4a formed by connecting between the outlet 8b of the pressure increase pump 8 and the inlet 6a of the in-loop pressure reduction valve 6, and the outlet 6b of the pressure reduction valve 6 in the loop. A gas supply flow path 4b formed by connecting between the inlet 9a of the pressure valve 9 and a gas return flow path 4c formed by connecting between the outlet 9b of the back pressure valve 9 and the inlet 8a of the booster pump 8. It consists of. Moreover, the pressure relationship between each flow path has the highest pressure of the gas pressure | voltage rise flow path 4a, and pressure is low in order of the gas pressure | voltage rise flow path 4a-> gas supply flow path 4b-> gas return flow path 4c.

  The flow meter 5 is provided between the inlet 2 a 1 of the anode 2 a of the fuel cell 2 and the outlet 6 b of the in-loop pressure reducing valve 6 in the circulation channel 4. The flow meter 5 measures the flow rate of the hydrogen gas supplied to the fuel cell 2 from the gas supply flow path 4b, that is, the pressure reducing valve 6 in the loop, and outputs the measured flow rate of the hydrogen gas to the control unit 13 as a measurement result. Yes.

  The in-loop pressure reducing valve 6 is connected between the flow meter 5 in the circulation flow path 4 and the outlet 7b of the buffer tank 7, and determines the pressure at the inlet 2a1 of the anode 2a of the fuel cell 2. The opening / closing (opening degree) of the pressure reducing valve 6 in the loop is controlled by the control unit 13, and the pressure of the hydrogen gas boosted by the booster pump 8 is reduced to keep the pressure of the gas supply passage 4 b at a constant set pressure. . As a result, the hydrogen gas at the flow rate (target set flow rate) of the fuel cell 2 performance evaluation condition desired by the user is kept at a constant set pressure at the inlet 2a1 of the anode 2a of the fuel cell 2 regardless of the internal pressure of the fuel cell 2. Supplied.

  The buffer tank 7 is connected between the inlet 6 a of the in-loop pressure reducing valve 6 and the outlet 8 b of the booster pump 8 in the circulation flow path 4. The buffer tank 7 temporarily stores the hydrogen gas in the gas pressure increasing flow path 4 a that has been pressurized by the pressure increasing pump 8.

  Note that the buffer tank 7 is not an indispensable configuration, and is provided when a booster pump 8 that generates pulsation, such as a diaphragm booster pump, is employed, depending on the degree of pulsation to be reduced. The volume is determined.

  The booster pump 8 is connected between the inlet 7 a of the buffer tank 7 and the outlet 9 b of the back pressure valve 9 in the circulation channel 4. The booster pump 8 sucks the hydrogen gas from the supply-side pressure reducing valve 3 and the unreacted hydrogen gas circulated through the circulation path 4 from the back pressure valve 9, and uses the pressure of the hydrogen gas in the gas pressure increasing flow path 4a as fuel. The pressure is increased to a pressure that can be supplied to the battery 2.

  The back pressure valve 9 is connected between the outlet 2 a 2 of the anode 2 a of the fuel cell 2 and the inlet 8 a of the booster pump 8 in the circulation channel 4. The back pressure valve 9 determines the pressure of the gas supply flow path 4b, and its opening / closing (opening) is controlled by the control unit 13 so that the pressure of the gas supply flow path 4b becomes the target set pressure.

  The pressure gauge 10 is provided in the gas return flow path 4 c between the outlet 9 b of the back pressure valve 9 and the inlet 8 a of the booster pump 8. The pressure gauge 10 measures the pressure of the hydrogen gas exhausted from the outlet 9b of the back pressure valve 9 and flows through the gas return flow path 4c, and outputs the measured pressure to the control unit 13 as a measurement result.

  The differential pressure gauge 11 measures the pressure difference of hydrogen gas between the inlet pressure and the outlet pressure of the anode 2 a of the fuel cell 2. That is, the differential pressure gauge 11 changes the pressure loss due to the blockage of the flow path by the water inside the fuel cell 2 or the swelling of the membrane during power generation, and the differential pressure of the hydrogen gas that fluctuates with the fluctuation of the pressure loss. The measured differential pressure is output to the control unit 13 as a measurement result.

  Although not shown, instead of the differential pressure gauge 11, an inlet side pressure gauge for measuring the inlet pressure of the fuel cell 2 and an outlet side pressure gauge for measuring the outlet pressure of the fuel cell 2 are provided, respectively. The pressure difference between the pressure measured by the outlet pressure gauge and the pressure measured by the outlet side pressure gauge can be output to the control unit 13 as a measurement result.

  The operation unit 12 includes an operation panel including buttons, keys, switches, indicators, and the like, for example. The operation unit 12 is used to input the initial conditions such as the target set flow rate and target set pressure of hydrogen gas and the minimum set pressure based on the minimum flow rate required for power generation of the fuel cell 2 in the performance evaluation conditions of the fuel cell 2 desired by the user. And set it.

  The control unit 13 is configured by a microcomputer such as a CPU, a ROM, and a RAM that collectively control the flow control device 1. Based on the comparison result between the target set flow rate input from the operation unit 12 and the flow rate measured by the flow meter 5, the control unit 13 controls the pressure reducing valve in the loop so that the flow rate of the gas supply channel 4b becomes the target set flow rate. 6 is controlled. Further, the control unit 13 determines the inlet pressure of the fuel cell 2 (the pressure of the gas supply channel 4b) based on the comparison result between the target set pressure input by the operation unit 12 and the differential pressure measured by the differential pressure gauge 11. The opening / closing (opening degree) of the back pressure valve 9 is controlled so as to reach the target set pressure. Furthermore, the control unit 13 supplies the gas return flow path 4c so that the pressure in the gas feedback channel 4c is equal to or higher than the minimum set pressure based on the comparison result between the minimum set pressure input by the operation unit 12 and the pressure measured by the pressure gauge 10. The opening / closing (opening degree) of the side pressure reducing valve 3 is controlled.

  Next, operation | movement of the gas flow control apparatus 1 of 1st Embodiment comprised as mentioned above is demonstrated. Here, when testing the power generation performance of the fuel cell 2, the flow rate of the hydrogen gas circulating in the circulation channel 4 is controlled by controlling the differential pressure between the inlet pressure and the outlet pressure of the anode 2 a of the fuel cell 2. Will be described with reference to FIG.

  First, initial conditions including a target set flow rate, a target set pressure, and a minimum set pressure of hydrogen gas supplied to the inlet 2a1 of the fuel cell 2 by an operation input of the operation unit 12 are set (ST1). After completing this setting, the booster pump 8 is turned on to start operation (ST2). When the operation of the booster pump 8 is started, the hydrogen gas sucked by the booster pump 8 is increased to a pressure at which the pressure of the gas supply flow path 4b can be supplied to the fuel cell 2, and the pressure reducing valve 6 in the loop is supplied from the buffer tank 7. To the inlet 2a1 of the anode 2a of the fuel cell 2.

  When hydrogen gas is supplied to the inlet 2a1 of the anode 2a of the fuel cell 2 and oxygen gas is supplied to the inlet 2b1 of the cathode 2b of the fuel cell 2, electric energy is generated by an electrochemical reaction between the hydrogen gas and oxygen gas. Generate and generate electricity. During power generation of the fuel cell 2, the following processing (1) is performed so that the flow rate of hydrogen gas supplied to the inlet 2a1 of the anode 2a of the fuel cell 2 approaches the flow rate (target set flow rate) of the performance evaluation condition desired by the user. ) To (3) are executed in parallel.

  The unreacted hydrogen gas generated by the fuel cell 2 is circulated through the circulation channel 4 (the gas return channel 4c → the gas supply channel 4b → the gas boost channel 4a) and boosted by the booster pump 8. Then, it is supplied again from the buffer tank 7 to the inlet 2 a 1 of the anode 2 a of the fuel cell 2 through the in-loop pressure reducing valve 6.

Processing (1)
The control unit 13 compares the target set flow rate input from the operation unit 12 with the flow rate measured by the flow meter 5, and determines whether or not the flow rate measured by the flow meter 5 has reached the target set flow rate (ST3). ). When the control unit 13 determines that the flow rate measured by the flow meter 5 is not the target set flow rate (ST3-No), the controller 13 turns the pressure reducing valve 6 in the loop until the flow rate measured by the flow meter 5 reaches the target set flow rate. “Open / close” is controlled (ST4). And the control part 13 discriminate | determines whether the pressure | voltage rise pump 8 is OFF (ST5). On the other hand, if it is determined that the flow rate measured by the flow meter 5 has reached the target set flow rate (ST3-Yes), it is determined whether the booster pump 8 is OFF (ST5). And if the control part 13 judges that the pressure | voltage rise pump 8 is OFF (ST5-Yes), a process (1) will be complete | finished. On the other hand, if the control part 13 judges that the pressure | voltage rise pump 8 is not OFF (ST5-No), it will return to the discrimination | determination process of ST3.

Processing (2)
The control unit 13 compares the target set pressure input from the operation unit 12 with the differential pressure measured by the differential pressure gauge 11, and determines whether or not the differential pressure measured by the differential pressure gauge 11 has reached the target set pressure. (ST6). When the control unit 13 determines that the differential pressure measured by the differential pressure gauge 11 is not the target set pressure (ST6-No), the control unit 13 changes the back pressure valve 9 until the differential pressure measured by the differential pressure gauge 11 reaches the target set pressure. “Open / close” is controlled (ST7). And the control part 13 discriminate | determines whether the pressure | voltage rise pump 8 is OFF (ST8). In contrast, when the control unit 13 determines that the differential pressure measured by the differential pressure gauge 11 has reached the target set pressure (ST6-Yes), the control unit 13 determines whether the booster pump 8 is OFF (ST8). And if the control part 13 judges that the pressure | voltage rise pump 8 is OFF (ST8-Yes), a process (2) will be complete | finished. On the other hand, if the control part 13 judges that the pressure | voltage rise pump 8 is not OFF (ST8-No), it will return to the determination process of ST6.

Processing (3)
The control unit 13 compares the pressure measured by the pressure gauge 10 with the minimum set pressure input from the operation unit 12, and determines whether or not the pressure measured by the pressure gauge 10 is equal to or lower than the minimum set pressure ( ST9). When the control unit 13 determines that the pressure measured by the pressure gauge 10 is equal to or lower than the minimum set pressure (ST9-Yes), the pressure measured by the pressure gauge 10 is set to supply the insufficient hydrogen gas from the gas supply device 3A. The supply-side pressure reducing valve 3 is controlled to “open / close” until the pressure reaches the minimum set pressure (ST10). And the control part 13 discriminate | determines whether the pressure | voltage rise pump 8 is OFF (ST11). On the other hand, when determining that the pressure measured by the pressure gauge 10 is not equal to or lower than the minimum set pressure (ST9-No), the control unit 13 determines whether or not the booster pump 8 is OFF (ST11). And if the control part 13 judges that the pressure | voltage rise pump 8 is OFF (ST11-Yes), a process (3) will be complete | finished. On the other hand, if the control part 13 judges that the pressure | voltage rise pump 8 is not OFF (ST11-No), it will return to the determination process of ST9.

  When the flow rate of the hydrogen gas supplied to the inlet 2a1 of the anode 2a of the fuel cell 2 is controlled to the flow rate (target set flow rate) of the performance evaluation condition by the above processes (1) to (3), Test power generation performance. Then, the flow rate (target set flow rate) and pressure (target set pressure) of the performance evaluation conditions of the fuel cell 2 desired by the user are variably set in predetermined steps, and the supply side pressure reducing valve 3, the in-loop pressure reducing valve 6, and the back pressure valve 9 are set. The flow rate of the hydrogen gas supplied to the inlet 2a1 of the anode 2a of the fuel cell 2 is adjusted by opening and closing, and the power generation performance of the fuel cell 2 for each flow rate in the performance evaluation condition is tested.

  As described above, in the gas flow rate control device 1A of the first embodiment of FIG. 1, the flow meter 5, the pressure gauge 10, and the differential pressure gauge 11 are provided, and the supply side pressure reduction is performed according to the procedure of the flowchart of FIG. The valve 3, the in-loop pressure reducing valve 6, and the back pressure valve 9 are each controlled to be opened / closed, and the gas flow rate supplied to the fuel cell 2 is adjusted to the target set flow rate.

  By the way, in the gas flow rate control device 1A of FIG. 1, both the flow meter 5 and the differential pressure gauge 11 are arranged in the circulation flow path 4 in order to obtain the flow rate (target set flow rate) of the performance evaluation condition of the fuel cell 2 desired by the user. However, only the flow meter 5 or only the differential pressure gauge 11 may be arranged and connected to the circulation flow path 4. Hereinafter, these configurations will be described with reference to FIGS. 3 and 4.

  FIG. 3 shows a schematic configuration of the gas flow control device 1 (1B) of the second embodiment. In FIG. 3, the same components as those in the gas flow rate control apparatus 1A in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

  The gas flow control device 1B of FIG. 3 has a configuration in which the back pressure valve 9 and the differential pressure gauge 11 are omitted from the gas flow control device 1A of FIG. 1, on the condition that the piping including the circulation flow path 4 is not vacuum. Among the processes (1) to (3) in the flowchart of FIG. 2, the process (1) and the process (3) are executed in parallel. That is, in the gas flow control device 1B of FIG. 3, the in-loop pressure reducing valve 6 is controlled by the process (1) based on the measurement result of the flow meter 5, and the flow rate of the hydrogen gas supplied from the inlet 2a1 of the fuel cell 2 is the target. It is adjusted to approach the set flow rate. Thereby, even if there is no differential pressure gauge 11, the differential pressure control between the inlet pressure and the outlet pressure of the fuel cell 2 is performed by opening and closing the pressure reducing valve 6 in the loop, and the performance evaluation condition of the fuel cell 2 that the user desires the flow rate of hydrogen gas The flow rate can be controlled.

  Next, FIG. 4 shows a schematic configuration of the gas flow rate control device 1 (1C) of the third embodiment. In FIG. 4, the same components as those in the gas flow control device 1 </ b> A in FIG. 1 are denoted by the same reference numerals and description thereof is omitted.

  The gas flow control device 1C in FIG. 4 has a configuration in which the flow meter 5 is omitted from the gas flow control device 1A in FIG. 1, and is located between the outlet 6b of the in-loop pressure reducing valve 6 and the inlet 2a1 of the anode 2a of the fuel cell 2. The measuring instrument 14 for monitoring the state of the gas supply flow path 4b is provided.

  The measuring instrument 14 includes, for example, a dew point meter, a pressure gauge, a thermometer, a gas analyzer, and a gas concentration meter. The dew point meter measures the moisture in the gas supply channel 4 b on the inlet 2 a 1 side of the anode 2 a of the fuel cell 2. The pressure gauge measures the pressure in the gas supply channel 4 b on the inlet 2 a 1 side of the anode 2 a of the fuel cell 2. The thermometer measures the temperature in the gas supply channel 4 b on the inlet 2 a 1 side of the anode 2 a of the fuel cell 2. The gas analyzer analyzes the gas composition of the gas component flowing in the gas supply channel 4 b on the inlet 2 a 1 side of the anode 2 a of the fuel cell 2. The gas concentration meter measures the concentration of each gas composition in the gas supply channel 4b on the inlet 2a1 side of the anode 2a of the fuel cell 2 for each gas composition. The measured concentrations of moisture, pressure, temperature, and gas components for each gas composition are input to the control unit 13 as monitor information. If the gas composition of the gas component flowing through the gas supply channel 4b is known in advance, the configuration of the gas analyzer can be omitted.

  In the gas flow rate control device 1C of FIG. 4, the control unit 13 includes a target set flow rate of hydrogen gas input from the operation unit 12 and monitor information (moisture, pressure, temperature, gas component) obtained by measurement by the measuring instrument 14. The target set differential pressure is calculated based on the concentration of each gas composition. Then, the control unit 13 compares the differential pressure measured by the differential pressure gauge 11 with the target set differential pressure obtained by calculation, so that the differential pressure measured by the differential pressure gauge 11 becomes the target set differential pressure. The pressure reducing valve 6 is controlled to open and close. Thus, even if there is no flow meter 5, the differential pressure control between the inlet pressure and the outlet pressure of the fuel cell 2 is performed by opening and closing the pressure reducing valve 6 in the loop, and the performance evaluation condition of the fuel cell 2 that the user desires the flow rate of hydrogen gas The flow rate can be controlled.

  The gas flow control device 1C in FIG. 4 is configured to control the opening and closing of the back pressure valve 9 by executing the process (2) in the flowchart in FIG. 2 based on the measurement result of the differential pressure gauge 11, but the back pressure valve 9 May be omitted, and the process (2) may not be executed.

  By the way, in the gas flow rate control device 1A in which both the flow meter 5 and the differential pressure gauge 11 of FIG. 1 are provided in the circulation flow path 4, the control unit 13 is supplied from the flow meter 5 or the differential pressure gauge 11 during power generation of the fuel cell 2. A flow meter 5 or a differential pressure gauge is used so that the flow rate of hydrogen gas supplied to the fuel cell 2 selectively captures the measurement result and approaches the flow rate (target set flow rate) of the performance evaluation condition of the fuel cell 2 desired by the user. The opening / closing (opening degree) of the supply-side pressure reducing valve 3 and the in-loop pressure reducing valve 6 may be controlled in accordance with the measurement result 11.

  In the gas flow control devices 1A, 1B, and 1C of the above-described embodiments, the configuration in which the loop-shaped circulation flow path 4 that returns from the outlet 2a2 of the anode 2a of the fuel cell 2 toward the inlet 2a1 is formed has been described. However, this configuration can also be adopted for the cathode 2b. That is, the loop-shaped circulation flow path 4 that returns from the outlet 2b2 of the cathode 2b of the fuel cell 2 toward the inlet 2b1 can be formed, and the same configuration as that of the anode 2a can be employed on the cathode 2b side.

  As described above, in the gas flow rate control device 1 of the present invention, the flow rate of the hydrogen gas supplied to the anode 2a of the fuel cell 2 during power generation of the fuel cell 2 is the flow rate of the fuel cell 2 performance evaluation condition desired by the user. The opening / closing (opening) of the supply-side pressure reducing valve 3, the in-loop pressure reducing valve 6, and the back pressure valve 9 is appropriately controlled as necessary so as to approach (target set flow rate). Thereby, the flow rate of the hydrogen gas when the unreacted hydrogen gas (fuel gas) exhausted from the fuel cell 2 at the time of power generation is supplied again to the fuel cell 2 through the circulation channel 4 is adjusted to satisfy the performance evaluation condition. The flow rate (target set flow rate) can be set. As a result, it is possible to perform a fuel cell evaluation test at the mounting level of a fuel cell vehicle that circulates and reuses unreacted hydrogen gas (fuel gas) without exhausting it. Specifically, the flow rate (target set flow rate) of the performance evaluation condition of the fuel cell 2 desired by the user is varied in predetermined steps, and the power generation performance of the fuel cell 2 mounted on the fuel cell vehicle is changed for each flow rate of the performance evaluation condition. It is possible to measure the flow rate of the fuel gas that can maximize the power generation performance. In addition, by setting various fuel cells in the flow control device 1 and performing a test, it is possible to grasp the power generation performance for each flow rate under performance evaluation conditions according to the type of fuel cell.

  Further, if the buffer tank 7 is disposed and connected between the booster pump 8 and the in-loop pressure reducing valve 6 in the circulation flow path 4, the pulsation in the case where the booster pump 8 such as a diaphragm type booster pump is employed can be reduced. Can stabilize the flow.

1 (1A, 1B, 1C) Gas flow control device 2 Fuel cell 3 Supply side pressure reducing valve 3A Gas supply device 4 Circulation flow path 4a Gas pressure increase flow path 4b Gas supply flow path 4c Gas feedback flow path 5 Flow meter 6 Pressure reduction in loop Valve 7 Buffer tank 8 Booster pump 9 Back pressure valve 10 Pressure gauge 11 Differential pressure gauge 12 Operation part 13 Control part 14 Measuring instrument

Claims (4)

In a fuel cell gas flow rate control device for controlling the flow rate of a gas supplied to a fuel cell that generates electrical energy by an electrochemical reaction between an anode gas and a cathode gas,
A fuel gas supply device for supplying gas to the fuel cell;
A loop-shaped circulation flow path returning from the outlet of the fuel cell toward the inlet is connected to the fuel gas supply device,
A pressure reducing valve in the loop and a pressure increasing pump are arranged in order from a position close to the inlet of the fuel cell,
A differential pressure gauge for measuring a differential pressure due to a pressure difference between an inlet pressure and an outlet pressure of the fuel cell in the circulation channel;
A measuring instrument for measuring the concentration of each gas composition of moisture, pressure, temperature, and gas components between the pressure reducing valve in the loop and the inlet of the fuel cell;
At the time of power generation of the fuel cell, a target set differential pressure is calculated based on a target set flow rate under performance evaluation conditions set in advance and a measurement result by the measuring instrument, and the differential pressure measured by the differential pressure gauge is calculated as the calculated target. A gas flow rate control apparatus comprising: a control unit that controls opening and closing of the pressure reducing valve in the loop so as to approach a set differential pressure. A pressure gauge that measures the pressure of the gas sucked into the booster pump through the circulation channel;
The gas flow rate control device according to claim 1, further comprising a supply-side pressure reducing valve that is controlled to be opened and closed by the control unit in accordance with the pressure measured by the pressure gauge. A gas flow rate control method using the gas flow rate control device according to claim 1,
After starting the operation of the booster pump, the differential pressure measured by the differential pressure gauge is compared with the calculated target set differential pressure, and when the differential pressure measured by the differential pressure gauge does not reach the target set differential pressure, A gas flow rate control method comprising the step of controlling opening and closing of the pressure reducing valve in the loop so that a differential pressure measured by the differential pressure gauge approaches the target set differential pressure. A gas flow rate control method using the gas flow rate control device according to claim 2,
Measuring the pressure of the gas sucked into the booster pump through the circulation channel;
Controlling the opening and closing of the supply-side pressure reducing valve when the measured pressure is equal to or lower than a preset minimum set pressure.

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