JP2006066295A - Gas supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply gas to a fuel cell without impairing reliability and economic efficiency. <P>SOLUTION: In the gas supply system 10, when the fuel cell 30 is started, a solenoid on-off valve 320 is opened to operate a pressure reducing part 300. When the solenoid on-off valve 320 is opened, hydrogen gas is supplied to the fuel cell 30 by a line from a hydrogen gas passage 210 via an auxiliary passage 310 and an orifice 330. When the operating time of the pressure reducing part 300 reaches a predetermined value, a control part 300 opens a solenoid on-off valve 220 in a secondary supply part 200 and supplies hydrogen gas to the fuel cell 30 from the hydrogen gas passage 210. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technical field of a gas supply system for supplying gas to a fuel cell.

  As an example of such a gas supply system, there is a system disclosed in Patent Document 1 (hereinafter referred to as “conventional technology”).

  According to the prior art, when the hydrogen gas in the tank is depressurized to a predetermined pressure by the pressure reducing valve, if the gas is not sufficiently depressurized due to a failure of the pressure reducing valve, etc. It is said that the high-pressure gas is prevented from being supplied to the fuel cell by releasing the high-pressure gas to the outside.

  Various devices have been conventionally developed as pressure valves and regulators for high-pressure gas (see Patent Documents 2 and 3).

JP 2002-370550 A Japanese Patent Laid-Open No. 7-215289 Japanese Utility Model Publication No. 3-104209

  However, the conventional technique has the following problems.

  Release of unused gas into the atmosphere is inappropriate and uneconomical from the viewpoint of effective use of gas. Also, depending on the type of gas, it may not be preferable to release it into the atmosphere. That is, with the conventional technology, it is difficult to supply gas with excellent reliability and economy.

  This invention is made | formed in view of the problem mentioned above, and makes it a subject to provide the gas supply system excellent in reliability and economical efficiency.

  In order to solve the above-described problems, a gas supply system according to the present invention is a gas supply system for supplying gas to a fuel cell, the storage means storing the gas, and the gas from the storage means Pressure reducing means for reducing the pressure to a predetermined pressure, a first on-off valve provided in a first gas flow path connecting the pressure reducing means and the fuel cell, and gas in the first gas flow path And a pressure reducing means capable of reducing the pressure in the first gas flow path by flowing in the gas supply system without going through the first on-off valve. To do.

  The “fuel cell” according to the present invention is a generic term for a cell having an aspect in which an electromotive force is obtained by an electrochemical reaction generated between an anode electrode and a cathode electrode sandwiching an electrolyte membrane. For example, one cell of a polymer electrolyte fuel cell Or a stack in which the cells are stacked. A fuel gas containing hydrogen and an oxidizing gas containing oxygen are supplied to the anode electrode and the cathode electrode, respectively. The “gas” according to the present invention refers to, for example, these fuel gas or oxidant gas. However, as long as the gas is supplied to the fuel cell, the gas may be any gas.

  The “storage unit” according to the present invention is a unit capable of storing the “gas” according to the present invention, and corresponds to, for example, a gas cylinder or a gas tank. The aspect of the storage means is not limited as long as the gas can be stored. For example, a gas cylinder or a gas tank can store the gas in a high pressure state. The “high pressure state” means that the pressure is higher than atmospheric pressure (current law indicates 10 atmospheres or more), and in particular, in an in-vehicle fuel cell system, it is considered to store at about 350 to 700 atmospheres. Has been. In the present invention, the quantity of the storage means is not limited at all.

  The gas stored in such a high pressure state is depressurized to a pressure that can be supplied to the fuel cell by the “decompression unit” according to the present invention, for example, a decompression valve, that is, “predetermined pressure” according to the present invention . In general, since the predetermined pressure is several atmospheric pressures, for example, 3 atmospheres or less, it is usually obtained through multiple pressure reductions. However, the “pressure reduction means” according to the present invention refers to the number of pressure reduction means and the pressure reduction means. Regardless of the number of times, this is a general term for all the gases that can be finally depressurized to a predetermined pressure. Here, the “predetermined pressure” may be strictly defined as a single numerical value, but may be defined as a certain pressure range that can be supplied to the fuel cell.

  According to the gas supply system of the present invention, during the operation, the gas that has been decompressed to a predetermined pressure by the decompression means is provided in the first opening and closing provided in the first gas flow path that connects the decompression means and the fuel cell. The fuel cell is supplied via a valve.

  Here, for example, when the pressure reducing means is a pressure reducing valve, even if there is no abnormality or failure in the pressure reducing valve, due to its structure, the force that presses the pressure reducing valve from the high pressure side and the low pressure (that is, the predetermined pressure) side respectively. Antagonized, the valve is close to no load, and gas is likely to leak from the high pressure side. In particular, when the gas is hydrogen gas, the gas is in the first gas flow path due to the fact that the hydrogen itself is light and stored at a relatively high pressure (eg, 350 atm). Considered to be easy to leak. In such a situation, if no measures are taken, the pressure in the first gas flow path will be the same as the high pressure side of the decompression means as time passes, and if the first on-off valve is opened in this state, In addition, an excessive pressure wave is applied to the fuel cell, and not only abnormal noise is generated, but also the fuel cell may be broken or damaged. In particular, if left unattended for a long time, the pressure in the first gas flow path tends to be equal to the high pressure side of the decompression means due to slight leakage.

  However, the gas supply system according to the present invention includes pressure reducing means capable of reducing the pressure in the first gas flow path. The pressure reducing means causes the gas in the first gas flow path to flow in the gas supply system without going through the first on-off valve during the operation. For example, in the gas supply system, the pressure reducing means communicates a portion having a lower pressure than that in the storage means or the first gas flow path with the first gas flow path. For example, the gas in the first gas flow path is returned to the storage means or returned to another part in the gas supply system. Since the rate of gas leakage from the decompression means is small, the pressure in the first gas flow path is reduced with the passage of a relatively short time or instantaneously by flowing in the gas supply system in this way. The Further, since the decompression means is provided for decompressing the gas originally stored in the storage means at a high pressure to a predetermined pressure, the pressure in the first gas flow path is predetermined unless the storage means is depleted of gas. The pressure should not be less than That is, the pressure in the first gas flow path is gradually reduced to approach a predetermined pressure by the action of the decompression means according to the present invention. Therefore, when the pressure in the first gas flow path is higher than the predetermined pressure, it is possible to supply hydrogen gas to the fuel cell after the pressure is reduced by the pressure reducing means, and the fuel cell On the other hand, high-pressure gas is not supplied. Furthermore, since the gas in the first gas flow path only flows in the gas supply system according to the present invention, the gas is not released to the outside (outside). Therefore, it is extremely excellent in reliability and economy.

  In one aspect of the gas supply system according to the present invention, the pressure reducing means causes the gas in the first gas flow path to flow when the fuel cell is started.

  When gas leaks from the decompression means, the pressure in the first gas flow path increases with time. Here, if the fuel cell is in operation (that is, during power generation), a gas having a predetermined pressure is supplied to the fuel cell constantly or at a constant time interval, so there is no problem. Accordingly, the high pressure in the first gas flow path is likely to occur when the fuel cell in a stopped state is restarted after a corresponding stop period. In such an aspect, when the fuel cell is started in this manner, the pressure reducing means causes the gas in the first gas flow path to flow, so that the gas can be efficiently supplied to the fuel cell. . It should be noted that the “when activated” described here may be all when activated from a stopped state, and it is determined that the pressure in the first gas flow path has become larger than a predetermined pressure. It may indicate a case where the system is activated after a certain time has elapsed.

  In another aspect of the gas supply system according to the present invention, the gas supply system further includes control means for opening and closing the first on-off valve in accordance with a pressure state in the first gas flow path.

  According to this aspect, the opening / closing of the first on-off valve is controlled by the control means in accordance with the pressure state in the first gas flow path. The phrase “according to the pressure state” is not strictly limited to using the pressure in the first gas flow path as a parameter. A concept including a case where the pressure state is estimated by a temporal, physical, or chemical change that can be determined that the pressure state in the first gas flow path has changed or has changed, for example, pressure reducing means The operation time may be used. According to this aspect, since the first opening / closing valve is opened / closed according to the pressure state in the first gas flow path, gas can be efficiently supplied to the fuel cell. Become.

  In one aspect of the gas supply system including a control unit, the control unit includes the first unit after a predetermined time has elapsed since the pressure reducing unit started to flow the gas in the first gas flow path. Open the on / off valve.

  The control means according to the present invention controls the first on-off valve in accordance with the pressure state in the first gas flow path, and the pressure state communicates with the first gas flow path and the gas flow path. If the volume of the other gas flow path, that is, the flow path through which the gas flows is determined by the pressure reducing means, it can be predicted in advance by simulation or the like, and such a volume is found. Even if not, it can be obtained or predicted experimentally or empirically. Therefore, it is not always necessary to actually measure the pressure in the first gas flow path. In this way, when the pressure in the first gas flow path can be obtained or predicted experimentally, empirically, or by simulation, the pressure in the first gas flow path is reduced to a predetermined pressure. By opening the first on-off valve with the passage of time that can be determined as having passed, it is possible to easily supply gas efficiently to the fuel cell. As already described, the pressure in the first gas flow path does not theoretically become lower than the predetermined pressure, so that the first on-off valve opens with a simple time without the above prediction. May be. At this time, the first on-off valve may be opened over a relatively long time with a corresponding margin.

  In another aspect of the gas supply system including a control unit, the gas supply system further includes a measurement unit that measures a pressure in the first gas flow path, and the control unit is configured so that the measured pressure is equal to or lower than the predetermined pressure. In some cases, the first on-off valve is opened.

  According to this aspect, the pressure in the first gas flow path is measured by the measuring means, and the first on-off valve is opened when the pressure is equal to or lower than the predetermined pressure. Gas can be supplied extremely safely.

  In another aspect of the gas supply system according to the present invention, the pressure reducing means causes the gas in the first gas flow path to flow according to the pressure state in the first gas flow path.

  According to this aspect, the pressure reducing means causes the gas to flow according to the pressure state in the first gas flow path. “Depending on the pressure state” described here means that, as described above, even in the case of strictly based on the pressure value, the first gas flow path in the first gas flow path that has been predicted or acquired in advance by some method is used. This includes cases based on pressure. As described above, when the gas in the first gas flow path is made to flow according to the pressure state, the gas can be efficiently supplied to the fuel cell.

  In one aspect of the gas supply system in which the pressure reducing means causes the gas to flow according to the pressure state in the first gas flow path, the pressure reduction means further includes a measuring means for measuring the pressure in the first gas flow path, The pressure reducing means causes the gas in the first gas flow path to flow when the measured pressure is larger than the predetermined pressure.

  When the pressure in the first gas flow path is in a range that can be regarded as the predetermined pressure, there is no particular need to reduce the pressure in the first gas flow path. In this aspect, since the pressure in the first gas flow path is measured, the gas in the first gas flow path is caused to flow when the pressure in the first gas flow path is larger than a predetermined pressure. Is possible. Therefore, it becomes possible to supply gas to the fuel cell very efficiently.

  In another aspect of the gas supply system according to the present invention, the pressure reduction means includes an auxiliary flow path that branches and merges so as to bypass the first on-off valve with respect to the first gas flow path, A second opening / closing valve provided in the auxiliary flow path; and a restricting means provided in the auxiliary flow path so as to be connected to the second opening / closing valve and restricting a flow rate of the passing gas.

  According to this aspect, during operation of the pressure reducing means, the gas in the first gas flow path passes through the auxiliary flow path provided so as to bypass the first on-off valve, and is opened to the second open / close state. The fuel cell is supplied via a valve and a restricting means. Here, the “restricting means” is defined as one that can restrict the flow rate of the gas passing through the limiting means, and is, for example, an orifice. When the restricting means is an orifice, the pressure in the auxiliary flow path can be simply reduced. However, the restriction means is not limited to the orifice, and the form of the restricting means is free within the definition. For example, a porous filter having a large flow path resistance may be used.

  In this way, the gas guided to the auxiliary flow path is appropriately decompressed by the action of the limiting means and then supplied to the fuel cell, so that the fuel cell is not damaged or damaged by the high-pressure gas. Further, in this aspect, even if the pressure in the first gas flow path is larger than the predetermined pressure, it is possible to supply gas to the fuel cell, so that a time delay until the pressure is returned to the predetermined value is reduced. It is possible to reduce and effective.

  Note that the first on-off valve may be opened when it is determined that the pressure in the first gas flow path has returned to a predetermined pressure or has returned. Further, the second on-off valve may be closed as the first on-off valve is opened. That is, as long as the first and second on-off valves are closed and opened within the time to reduce the pressure in the first gas flow path, the first and second on-off valves are opened and closed. The timing may be freely determined.

  In another aspect of the gas supply system according to the present invention, the pressure reducing means includes a second gas flow path that leads from the first gas flow path to the storage means without passing through the pressure reducing means, and the first gas flow path. And a filling unit that is provided in the second gas channel and fills the storage unit with the gas in the first gas channel.

  According to this aspect, during the operation of the pressure reducing means, the gas in the first gas flow path is guided from the first gas flow path to the second gas flow path connected to the storage means without going through the pressure reducing means. Then, it is stored again in the storage means by the filling means provided on the second flow path. Therefore, the pressure in the first gas flow path is gradually reduced. Further, for example, when the pressure in the first gas flow path is reduced to a predetermined pressure provided by the decompression means while the first on-off valve is closed, the pressure in the first gas flow path is The gas is circulated in a circulation path including a storage means, a decompression means, and a pressure reduction means.

  Here, the “filling means” may have any form as long as it can generate a gas flow from the decompression means through the second flow path to the storage means. If it is compressors, such as a compressor, it is possible to fill a storage means with gas efficiently. Further, in the path from the second gas flow path to the storage means, some backflow prevention means may be provided for the purpose of preventing the backflow of gas from the storage means.

  According to this aspect, gas can be used very efficiently, and high economic efficiency is provided.

  In the gas supply system including such a filling means, the filling means is further configured to be connectable to an external storage means for storing the same type of gas as the gas stored by the storage means at a lower pressure than the storage means. The storage means may be filled with at least one of the gas in the first flow path and the gas stored in the external storage means. Alternatively, the filling unit may be further configured to be connectable to a power supply unit that supplies power necessary for the filling to the filling unit.

  In such a case, for example, an automobile equipped with a fuel cell system including the gas supply system according to this aspect is filled with gas generated from an electrolyzer installed at home or the like via a filling means. This is possible simply. Alternatively, at this time, the power required for filling, such as the power of the filling means and the power source for control, can be taken in from the outside. Therefore, even when the gas in the storage means is insufficient, it is possible to easily fill the gas. In this case, at least a part of the second gas supply path and the gas flow path for the external filling may be configured in common with each other.

  Such an operation and other advantages of the present invention will be clarified by embodiments described below.

<Embodiment>
Embodiments of the present invention will be described below with reference to the drawings.
<First Embodiment>
<Configuration of gas supply system 10>
First, the configuration of the gas supply system according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of the gas supply system 10.

  In FIG. 1, the gas supply system 10 includes a primary supply unit 100, a secondary supply unit 200, a pressure reduction unit 300, and a control unit 400. Further, the replenishment unit 20 is connected to the primary supply unit 100, and the fuel cell 30 is connected to the secondary supply unit.

  The primary supply unit 100 includes a hydrogen gas tank 110, a supplementary pipe 120, a backflow prevention valve 130, a supply pipe 140, a primary pressure reducing valve 150, a supply collective pipe 160, a supplementary collective pipe 170, and a secondary pressure reducer valve 180. Is provided.

  The hydrogen gas tank 110 is an example of the “storage unit” according to the present invention, and stores hydrogen gas as an example of the “gas” according to the present invention at a high pressure of about 350 atm. A total of four hydrogen gas tanks 110 are installed in the gas supply system 10, and each has the same configuration. The internal pressure of the hydrogen gas when stored in the hydrogen gas tank 110 is not limited to 350 atm described here, and may be about 200 atm as in the case of a normal gas cylinder or the like. It may be about 700 atmospheres.

  The hydrogen gas tank 110 includes a supplementary pipe 120. When the hydrogen gas in the hydrogen gas tank 110 is deficient or predicted to be deficient in the operation process of the fuel cell 30 to be described later, the replenishment pipe 120 is connected to the hydrogen gas tank 110 from a replenishment source (not shown). The hydrogen gas can be appropriately replenished through the replenishing unit 20 that performs the replenishment. The replenishment pipe 120 is provided with a backflow prevention valve 130, which prevents the hydrogen gas in the hydrogen gas tank 110 from flowing back to the outside via the replenishment pipe 120. It is configured as follows. Further, the replenishment pipes 120 provided in the hydrogen gas tanks 110 communicate with the replenishment collective pipes 170 in an airtight manner.

  The replenishment unit 20 is connected to an end of the replenishment collecting pipe 170 and includes a hydrogen gas replenishment coupler 21 and a backflow prevention valve 22. The hydrogen gas replenishing coupler 21 is configured to be connected to a replenishment source (not shown) while maintaining airtightness during such replenishment. Further, like the backflow prevention valve 130, the backflow prevention valve 22 is configured to prevent the backflow of hydrogen gas from the hydrogen gas replenishment coupler 21 toward the replenishment source. 170 is provided.

  The hydrogen gas tank 110 includes a supply pipe 140 separately from the supplementary pipe 120. The supply pipe 140 is provided with a primary pressure reducing valve 150, and the supply pipe 140 extending from each hydrogen gas tank 110 keeps the supply collective pipe 160 airtight through the primary pressure reducing valve 150. Communicate. A secondary pressure reducing valve 180 is provided at the end of the supply collecting pipe 160.

  The secondary supply unit 200 includes a hydrogen gas flow path 210 and an electromagnetic on-off valve 220.

  The hydrogen gas flow path 210 is an example of the “first gas flow path” according to the present invention, and communicates with the supply collecting pipe 160 through the secondary pressure reducing valve 180 while maintaining airtightness. The hydrogen gas passage 210 is configured such that the hydrogen gas stored in the hydrogen gas tank 110 is supplied to the fuel cell 30 via the hydrogen gas passage 210.

  The electromagnetic on-off valve 220 is an example of the “first on-off valve” according to the present invention, and is provided on the hydrogen gas flow path 210. The electromagnetic on-off valve 220 is controlled to be either open or closed by a control unit 400 described later. In the open state, hydrogen gas in the hydrogen gas flow path 210 is supplied to the fuel cell 30. It is configured as follows.

  Note that the supplementary pipe 120 and the supplementary collective pipe 170 may be configured as a single pipe from the beginning. Similarly, the supply pipe 140 and the supply collective pipe 160 may be configured as a single pipe. Further, the supply collecting pipe 160 and the hydrogen gas flow path 210 may be configured as a single pipe.

  Here, the fuel cell 30 will be described. The fuel cell 30 is a stack of polymer electrolyte fuel cells as an example of the “fuel cell” according to the present invention. This stack is composed of a plurality of fuel cells. Each individual fuel cell has an anode electrode, a cathode electrode, and an electrolyte membrane sandwiched between them (all of which are not shown), and the hydrogen of the anode electrode and the oxygen of the cathode electrode are used as the electrolyte. An electromotive force can be generated by electrochemical reaction through the film. The hydrogen of the anode electrode is hydrogen gas supplied to the fuel cell 30 via the hydrogen gas flow path 210, and the gas supply system 10 controls the supply of hydrogen gas to the fuel cell 30. System.

  In FIG. 1, a path for supplying an oxidant gas containing oxygen to the cathode electrode of the fuel cell 30 is omitted.

  The pressure reducing unit 300 includes an auxiliary flow path 310, an electromagnetic opening / closing valve 320 provided on the auxiliary flow path 310, and an orifice 330 provided on the auxiliary flow path 320 subsequent to the electromagnetic opening / closing valve 320.

  The auxiliary flow path 310 branches off from the hydrogen gas flow path 210 on the secondary pressure reducing valve 180 side with respect to the electromagnetic on-off valve 220 and joins again with the hydrogen gas flow path 210 on the fuel cell 30 side with respect to the electromagnetic open / close valve 220. It is configured like this. The auxiliary flow path 310 is an example of an “auxiliary flow path” according to the present invention that bypasses the electromagnetic on-off valve 220. The auxiliary flow channel 310 is a flow channel having the same material and shape as the hydrogen gas flow channel 210, but the material and shape are free as long as the effects according to the present embodiment, which will be described later, are not hindered. .

  The electromagnetic on-off valve 320 is an example of the “second on-off valve” according to the present invention, and is electrically connected to the control unit 400 in the same manner as the electromagnetic on-off valve 220. The electromagnetic on-off valve 320 is controlled to be in an open state or a closed state according to control by the control unit 400.

  The orifice 330 is an example of the “limiter” according to the present invention. Here, the orifice 330 will be described with reference to FIG. Here, FIG. 2 is a schematic cross-sectional view of the orifice 330. 2A shows a cross section in the direction along the auxiliary flow path, and FIG. 2B shows a cross section in the direction orthogonal to the auxiliary flow path.

  In FIG. 2A, the orifice 330 includes a metal cylindrical portion 331 and a disc portion 332 installed in the cylindrical portion 331. The cylindrical portion 331 communicates with the auxiliary flow path 310 (omitted in FIG. 2) so as to have the same inner diameter and in an airtight manner. Therefore, except for the disc portion 332, the auxiliary flow path 310 and the orifice 330 are communicated. Constitutes one flow path. In addition, the material which comprises this orifice 330 is free as long as it is chemically stable with respect to hydrogen gas.

  In FIG. 2B, the disc portion 332 has a plurality of throttle holes 332b in a disc-like base material 332a, and covers the cross section of the cylindrical portion 331 in an airtight and partial manner at the installation location. ing. Accordingly, the exhaust resistance increases at the place where the disk portion 332 is installed, so that the flow rate of the passing gas changes. In the orifice 330, the number and size of the throttle holes 332b are not limited in any way as long as it is possible to give some exhaust resistance to the gas passing through the orifice 330. Accordingly, the internal structure of the orifice 330 is not limited. There is no limitation. For example, the orifice 330 may have a configuration in which a plurality of disk portions 332 are arranged.

  Returning to FIG. 1, the pressure reducing unit 300 is configured such that the hydrogen gas in the auxiliary flow path 310 merges with the hydrogen gas flow path 210 after passing through the electromagnetic on-off valve 320 and the orifice 330.

  The control unit 400 includes a CPU (Central Processing Unit) 410 and a memory 420.

The CPU 410 is an example of the “control unit” according to the present invention, and is electrically connected to the electromagnetic on-off valve 220 and the electromagnetic on-off valve 320, respectively, and controls the open / close state of these. Memory 420 is a CPU410 and electrically connected to the storage means, switching conditions when the CPU410 to open and close the solenoid valve 220 and solenoid valve 320, for example, store a reference value _{T 0} such elapsed time to be described later is doing. The memory 420 may be a read-only storage unit such as a ROM (Read Only Memory) or a rewritable storage medium such as a RAM (Random Access Memory) or an HDD (Hard Disk Drive). Also good.

Further, in the control unit 400, the CPU 410 controls the above-described opening / closing operation based on a start command for starting the fuel cell 30 and a stop command for stopping the fuel cell 30, which are transmitted from a control device (not shown). It is configured to be able to do.
<Operation of Gas Supply System 10>
Next, the operation of the gas supply system 10 having the above configuration will be described with reference to FIG.

  The hydrogen gas is stored in the hydrogen gas tank 110 at an internal pressure of 350 atm. The primary pressure reducing valve 150 provided in the supply pipe 140 increases the pressure of the hydrogen gas to a primary pressure of about several tens of atm. Reduce pressure. Therefore, the pressure in the supply collecting pipe 160 communicating with the primary pressure reducing valve 150 is maintained at the primary pressure.

The secondary pressure reducing valve 180 further reduces the primary pressure to a secondary pressure P ₀ suitable for supply to the fuel cell 30. This secondary pressure reducing valve 180, the pressure in the hydrogen gas passage 210 is normally maintained at a pressure _{P 0.} The primary pressure reducing valve 150 and the secondary pressure reducing valve 180 are examples of the “pressure reducing means” according to the present invention, and the pressure P ₀ is an example of the “predetermined pressure” according to the present invention. In the present embodiment, the “pressure P ₀ ” is not a pressure defined by a single value, but a pressure defined within a predetermined pressure range that allows the fuel cell 30 to operate properly. I will point.

By the way, in the fuel cell 30 that has passed through a corresponding stop period, the pressure in the hydrogen gas flow path 210 may exceed the pressure P _{0 due} to hydrogen gas leaking from the secondary pressure reducing valve 180. For example, when the stop period is long, the pressure rises to a pressure equivalent to that in the supply collecting pipe 160, that is, about several tens of atmospheres. Further, when the pressure reducing means is not configured in two stages as in the present embodiment but is configured to reduce the pressure from the hydrogen gas tank 110 to the pressure P ₀ by a single pressure reduction, the inside of the hydrogen gas flow path 210 is It can be considered that the pressure rises to several hundred atmospheres. If such a high-pressure gas is supplied to the fuel cell 30 without any pressure reduction, the fuel cell 30 may be broken or damaged. Therefore, the gas supply system 10 enables stable supply of hydrogen gas to the fuel cell 30 by performing a startup process described below when the fuel cell 30 is started.
<Details of startup processing>
Below, with reference to FIG. 3, the starting process in the gas supply system 10 is demonstrated. FIG. 3 is a flowchart of the activation process. In the gas supply system 10, when the fuel cell 30 is stopped, both the electromagnetic on-off valve 220 and the electromagnetic on-off valve 320 are closed.

  In FIG. 3, first, the CPU 410 determines whether or not there is an activation command for the fuel cell 30 (step S201). In the gas supply system 10, the CPU 410 monitors the presence or absence of an activation command at every fixed clock timing while the fuel cell 30 is stopped. When it is determined that there is no activation command (step S201: NO), the CPU 410 repeats step S201 until there is a activation command.

  When the CPU 410 receives an activation command for instructing activation of the fuel cell 30 (step S201: YES), the CPU 410 opens the electromagnetic on-off valve 320, allows the hydrogen gas in the hydrogen gas channel 210 to pass through the auxiliary channel 310, and the orifice 330. To the fuel cell 30 (step S202).

  Since the hydrogen gas that has passed through the orifice 330 is decelerated due to the exhaust resistance increased by the throttle hole 332b, the hydrogen gas is supplied to the fuel cell 30 in a state where the pressure is lower than the pressure in the hydrogen gas flow path 210. Supplied.

On the other hand, when opening the solenoid valve 320, CPU 410 may by built-in timer and starts an elapsed time monitoring of _{T 1} of the from the time the solenoid valve 320 is opened (step S203). The memory 420 stores in advance a reference value T ₀ of elapsed time for determining whether or not the pressure in the hydrogen gas flow path 210 has become equal to or lower than the pressure P ₀ . CPU410 the elapsed time _{T 1} is, wherein it is determined whether or not the reference value _{T 0} or more according (step S204).
If the elapsed time _{T 1} is less than the _{T 0} (step S204: NO), CPU 410, when with repeating step S204, the elapsed time _{T 1,} becomes _{T 0} or more (step S204: YES), the CPU 410 Then, the electromagnetic on-off valve 220 is opened, and hydrogen gas is supplied to the fuel cell 30 through the hydrogen gas flow path 210 (step S205).

Here, the reference value T ₀ of the elapsed time stored in the memory 420 is the time during which the pressure reducing unit 300 is operating (that is, the time during which the electromagnetic on-off valve 320 is opened), the hydrogen gas flow path 210 The pressure in the hydrogen gas flow path 210 becomes equal to or lower than the pressure P ₀ (strictly speaking, the pressure of the secondary pressure reducing valve 180 does not become less than the pressure P ₀ under normal conditions). or it is set to a value which is expected to be less than the pressure P _0. The correlation is obtained in advance by empirical, experimental, simulation, or the like. Further, since the volume of the hydrogen gas flow path 210 that is expected to cause a pressure increase is sufficiently small with respect to the fuel cell 30, the hydrogen gas flow path 210 even when such correlation is not clearly obtained. When the time during which the internal pressure becomes P ₀ or less can be predicted, such a time or a time obtained by adding a margin to such a time may be set as the reference value T ₀ . Conversely, the orifice 330 and the auxiliary flow path 310 may be configured so that the pressure in the hydrogen gas flow path 210 returns to the pressure P ₀ in a desired elapsed time.

When the electromagnetic opening / closing valve 220 is opened, the CPU 410 closes the electromagnetic opening / closing valve 320 (step S206), and the activation process according to the present embodiment is completed. When the electromagnetic on-off valve 320 is closed, the hydrogen gas channel 210 is the only path for supplying hydrogen gas to the fuel cell 30, and hydrogen gas is compared with the case where the auxiliary channel 310 is used in combination. Can be used efficiently. However, since the pressure in the hydrogen gas flow path 210 should be P ₀ or less when the electromagnetic on-off valve 220 is opened, no problem occurs even if the electromagnetic on-off valve 320 is not closed. . That is, hydrogen gas may be supplied to the fuel cell 30 through both the hydrogen gas flow path 210 and the auxiliary flow path 310. In this case, the activation process may be terminated when the electromagnetic opening / closing valve 220 is opened. Alternatively, if the pressure in the hydrogen gas flow path 210 is sufficiently reduced by opening the electromagnetic on-off valve 320 in steps S202 to S204, the electromagnetic on-off valve 320 in step S206 is closed, and the electromagnetic on-off valve in step S205 is closed. It is also possible to do this prior to opening 220.

  As already described, the CPU 410 is configured to be able to acquire a stop command for stopping the fuel cell 30. When stopping the fuel cell 30 based on such a stop command, the CPU 410 closes the electromagnetic on-off valve 220 (and possibly the electromagnetic on-off valve 320) to stop the supply of hydrogen gas to the fuel cell 30. Then, the fuel cell 30 is stopped.

As described above, according to the gas supply system 10 according to the present embodiment, the pressure reducing unit 300 operates when the fuel cell 30 is started, in which the pressure in the hydrogen gas flow path 210 is considered to be larger than the pressure P _0. Since the decompressed hydrogen gas can be supplied to the fuel cell 30, it has extremely high reliability. In addition, the gas in the hydrogen gas flow path 210 is finally supplied to the power generation of the fuel cell 30 even if the path is different, and the hydrogen gas is not wasted. Therefore, it is extremely economical.

The CPU 410 may be configured to be able to acquire a lapse of time after the fuel cell 30 is stopped. Since the elapsed time after the stop has a correlation with the pressure increase in the hydrogen gas flow path 210 in a certain time range, the reference value of the elapsed time may be different depending on the elapsed time. At this time, it is preferable that the memory 420 stores a plurality of such reference values. In this case, for example, the fuel cell 30 can always be optimally activated.
Second Embodiment
The embodiment of the gas supply system according to the present invention is not limited to the gas supply system 10 according to the first embodiment described above. The gas supply system according to the second embodiment of the present invention will be described below.
<Configuration of gas supply system 40>
First, the configuration of the gas supply system according to the second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a schematic configuration diagram of the gas supply system 40. In FIG. 4, the same reference numerals are given to portions overlapping with those in FIG. 1 described above, and the description thereof is omitted.

  In FIG. 4, the gas supply system 40 is different from the gas supply system 10 according to the first embodiment in that a pressure reducing unit 500 is provided instead of the pressure reducing unit 300.

  The pressure reduction unit 500 includes a circulation channel 510 that communicates from the hydrogen gas channel 210 to the supplementary collecting pipe 170, a compressor 520 provided on the circulation channel 510, a motor 530 that drives the compressor 630, and hydrogen. A pressure gauge 540 capable of measuring the pressure in the gas flow path 210 is provided.

  The circulation channel 510 is a channel having a configuration similar to that of the hydrogen gas channel 210 and communicates with the hydrogen gas channel 210 at one end thereof while maintaining airtightness. The other end of the circulation channel 510 communicates with the supplementary collecting pipe 170 in an airtight manner. The circulation channel 510 is an example of the “second gas channel” according to the present invention.

  The compressor 520 is an example of a “filling unit” according to the present invention configured to be able to create a gas flow from the hydrogen gas flow path 210 toward the supplementary collecting pipe 170.

  The motor 530 is electrically connected to the control unit 400 and is configured to be able to drive the compressor 520 in accordance with the control of the CPU 410.

The pressure gauge 540 is an example of the “measuring unit” according to the present invention configured to be able to measure the pressure in the hydrogen gas flow path 210. Similarly to the motor 530, the pressure gauge 540 is electrically connected to the control unit 400, and can measure the pressure according to control by the CPU 410. The measured pressure is constantly monitored by the control unit 400 at a fixed timing. Incidentally, the memory 420, the reference value of the pressure of the hydrogen gas flow path 210 (i.e., a value corresponding to the pressure P ₀₎ is stored in advance. The pressure reducing unit 500 is configured as described above.
<Details of startup processing>
Next, the startup process in the gas supply system 40 will be described with reference to FIG. FIG. 5 is a flowchart of the startup process in the gas supply system 40. In FIG. 5, the same parts as those in FIG. 3 described above are denoted by the same reference numerals and description thereof is omitted.

In FIG. 5, when there is an activation command, the CPU 410 determines whether the pressure P ₁ in the hydrogen gas flow path 210 measured by the pressure gauge 540 is equal to or lower than the pressure reference value P ₀ stored in the memory 420. It is determined whether or not (step S301). When the pressure in the hydrogen gas flow path 210 is higher than the pressure P _{0 for} some reason (step S301: NO), the CPU 410 operates the motor 530 and operates the compressor 520 (step S302). Further, in step S301, if already pressure in the hydrogen gas passage 210 was pressure _{P 0} or less (step S301: YES), CPU 410 advances the process to step S205.

  When the compressor 520 is operated, the hydrogen gas existing in the hydrogen gas flow path 210 starts to flow in the direction of the replenishment collecting pipe 170 through the circulation flow path 510 by the gas flow created by the compressor 520. The replenishment collective piping 170 prevents the gas flow from passing through the hydrogen gas replenishment coupler 21 to the outside by the action of the backflow prevention valve 22, so that each hydrogen gas tank passes through the replenishment piping 120. 110. That is, the hydrogen gas once supplied to the hydrogen gas passage 210 is refluxed to the hydrogen gas tank 110 again by the action of the compressor 520.

When such hydrogen gas recirculation continues, the pressure in the hydrogen gas flow path 210 is gradually reduced and approaches the pressure of the hydrogen gas flow path 210 controlled by the secondary pressure reducing valve 180 (ie, the pressure P ₀ ). . However, even if the pressure in the hydrogen gas passage 210 is instantaneously reduced to less than the pressure P _{0, the} secondary pressure reducing valve 180 is instantaneously opened and hydrogen gas is supplied into the hydrogen gas passage 210. the pressure of the hydrogen gas flow path 210 is maintained at a pressure _{P 0.} In this state, after all, the hydrogen gas again passes through the hydrogen gas flow path 210, the circulation flow path 510, the supplementary collective pipe 170, the supplementary pipe 120, the supply pipe 140, and the supply collective pipe 160 again. It will return to the hydrogen gas flow path 210. That is, the hydrogen gas simply circulates in the gas supply system 40.

CPU410, when operating the compressor 520, again, the pressure _{P 1} of the hydrogen gas flow path 210 it is determined whether or not more than the reference value (step S303). When the pressure in the hydrogen gas flow path 210 is larger than the pressure P ₀ (step S303: NO), the CPU 410 repeats step S303 to fill the hydrogen gas tank 110 with the hydrogen gas in the hydrogen gas flow path 210 and When it is determined that the pressure in the gas flow path 210 is equal to or lower than the reference value (step S303: YES), the CPU 410 stops the motor 530 and stops the operation of the compressor 520 (step S304). When the operation of the compressor 520 stops, the flow of hydrogen gas through the circulation channel 510 stops. When the compressor 520 is stopped, the CPU 410 shifts the process to step S205.

  In step S <b> 205, the CPU 410 opens the electromagnetic on-off valve 220 and supplies hydrogen gas to the fuel cell 30. When hydrogen gas is supplied from the hydrogen gas flow path 210 to the fuel cell 30 via the electromagnetic on-off valve 220, the start-up process according to this embodiment is completed.

  As described above, according to the present embodiment, the pressure in the hydrogen gas flow path 210 is constantly monitored, and the hydrogen gas can be appropriately supplied to the fuel cell 30, thereby further improving the reliability. improves.

  The pressure reducing unit 300 according to the first embodiment described above may include a pressure gauge that measures the pressure in the hydrogen gas flow path 210. Conversely, the pressure reducing unit 500 according to the present embodiment may not include a pressure gauge. In this case, as in the first embodiment, if the operation of the compressor 520 is controlled based on the elapsed time, the same effect can be obtained.

In FIG. 5, the startup process related to the startup of the fuel cell 30 is shown. However, the timing for operating the pressure reducing unit 500 is not limited to the startup of the fuel cell 30. For example, when the pressure in the hydrogen gas flow path 210 is larger than the reference value P ₀ , the CPU 410 operates the pressure reducing unit 500 regardless of the state of the fuel cell 30 to adjust the pressure in the hydrogen gas flow path 210. May be. In addition, a second reference value that determines whether or not to execute the pressure adjustment may be stored in the memory 420, and the pressure adjustment may be executed based on the second reference value. Thus, according to this embodiment, since the pressure in the hydrogen gas flow path 210 is constantly monitored, it is possible to always keep the pressure in the hydrogen gas flow path 210 at the pressure P ₀ . Furthermore, even when the inside of the hydrogen gas passage 210 becomes higher than the pressure P _{0 for} some reason during the power generation of the fuel cell 30, it is possible to appropriately cope with it.
<Modification>
In the gas supply system 40, the hydrogen gas tank 110 may be configured to be replenished with gas from a gas supply source installed outside via the compressor 520. Such a modification of the present invention will be described with reference to FIG. FIG. 6 is a schematic configuration diagram of the gas supply system 50. In the figure, the same parts as those in FIG.

  In FIG. 6, the gas supply system 50 is different from the gas supply system 40 in that it includes an external gas supply device 51, an external supply flow path 52, a backflow prevention valve 53, an electromagnetic open / close valve 54, and an external power supply 55.

  The external gas supply device 51 is, for example, a water electrolysis device installed in a home or the like, and is a device configured to generate hydrogen gas by electrolyzing water. The external supply pipe 52 is a pipe configured to be able to connect the external gas supply device 51 and the compressor 520 while maintaining airtightness. The backflow prevention valve 53 is provided on the external supply pipe 52 and is configured so that the gas in the pipe does not backflow toward the external supply device 51. The electromagnetic opening / closing valve 54 is provided on the external supply pipe 52 and is configured to be able to perform an opening / closing operation under the control of the CPU 410. The external power source 55 is, for example, a household power source or a power source appropriately equipped with a converter, and is electrically connected to the control unit 400 and the pressure reducing unit 500 by a connector (not shown). On the other hand, electric power as an example of “power required for filling” according to the present invention can be supplied.

  During the operation of the gas supply system 50 having such a configuration, the CPU 410 operates the compressor 520 and opens the electromagnetic on-off valve 54 to compress the hydrogen gas generated by the external gas supply device 51. The pressure is increased and supplied to the hydrogen gas tank 110.

  Thus, according to the gas supply system 50, the circulation flow path 510 and the compressor 520 provided for reducing the pressure in the hydrogen gas flow path 210 are also used for hydrogen gas replenishment to the hydrogen gas tank. Is possible. Therefore, for example, at home, the hydrogen gas tank 110 can be filled with hydrogen gas relatively easily.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and a gas supply system with such a change is also possible. Moreover, it is included in the technical scope of the present invention.

1 is a schematic configuration diagram of a gas supply system 10 according to a first embodiment of the present invention. 3 is a schematic cross-sectional view of an orifice 330 in the gas supply system 10. FIG. 4 is a flowchart of start-up processing in the gas supply system 10. It is a schematic block diagram of the gas supply system 40 which concerns on 2nd Embodiment of this invention. 4 is a flowchart of a startup process in the gas supply system 40. It is a schematic block diagram of the gas supply system 50 which concerns on the modification of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Gas supply system, 20 ... Replenishment part, 21 ... Hydrogen gas replenishment coupler, 22 ... Backflow prevention valve, 30 ... Fuel cell, 40 ... Gas supply system, 50 ... Gas supply system, 51 ... External gas supply apparatus, 52 DESCRIPTION OF SYMBOLS ... External supply piping, 53 ... Backflow prevention valve, 54 ... Electromagnetic on-off valve, 55 ... External power supply, 100 ... Primary supply part, 110 Hydrogen gas tank, 120 ... Replenishment piping, 130 ... Backflow prevention valve, 140 ... Supply piping , 150 ... primary pressure reducing valve, 160 ... supply collecting pipe, 170 ... refilling collecting pipe, 180 ... secondary pressure reducing valve, 200 ... secondary supply section, 210 ... hydrogen gas flow path, 220 ... electromagnetic on-off valve, 300 DESCRIPTION OF SYMBOLS ... Pressure reduction part, 310 ... Auxiliary flow path, 320 ... Electromagnetic switching valve, 330 ... Orifice, 400 ... Control part, 410 ... CPU, 420 ... Memory, 500 ... Pressure reduction part, 510 ... Circulation flow path, 520 Compressor, 530 ... motor, 540 ... pressure gauge.

Claims (11)

A gas supply system for supplying gas to a fuel cell,
Storage means for storing the gas;
Pressure reducing means for reducing the gas from the storage means to a predetermined pressure;
A first on-off valve provided in a first gas flow path connecting the decompression means and the fuel cell;
By causing the gas in the first gas flow path to flow in the gas supply system without going through the first on-off valve, the pressure in the first gas flow path can be reduced. A gas supply system comprising: a pressure reducing unit. The gas supply system according to claim 1, wherein the pressure reducing means causes the gas in the first gas flow path to flow when the fuel cell is started.   The gas supply system according to claim 1, further comprising a control unit that opens and closes the first on-off valve in accordance with a pressure state in the first gas flow path. The control means opens the first on-off valve after a predetermined time has elapsed since the pressure reducing means started to flow the gas in the first gas flow path. 4. The gas supply system according to 3. A measuring means for measuring the pressure in the first gas flow path;
The gas supply system according to claim 3, wherein the control means opens the first on-off valve when the measured pressure is equal to or lower than the predetermined pressure. The gas supply system according to claim 1, wherein the pressure reducing unit causes the gas in the first gas flow path to flow according to the pressure state in the first gas flow path. A measuring means for measuring the pressure in the first gas flow path;
The gas supply system according to claim 6, wherein the pressure reducing unit causes the gas in the first gas flow path to flow when the measured pressure is larger than the predetermined pressure. The pressure reducing means includes
An auxiliary flow path that branches and merges so as to bypass the first on-off valve with respect to the first gas flow path;
A second on-off valve provided in the auxiliary flow path;
The limiting means which restrict | limits the flow volume of the gas provided in the said auxiliary | assistant flow path so that it may mutually precede and follow the said 2nd on-off valve is provided. The gas supply system described. The pressure reducing means includes
A second gas flow path that leads from the first gas flow path to the storage means without going through the decompression means;
8. The apparatus according to claim 1, further comprising: a filling unit that is provided in the second gas flow path and fills the storage unit with a gas in the first gas flow path. The gas supply system described. The filling means is further configured to be connectable to an external storage means for storing a gas of the same type as the gas stored by the storage means at a lower pressure than the storage means, and the gas in the first flow path and The gas supply system according to claim 9, wherein at least one of the gases stored in the external storage unit is filled in the storage unit. The gas supply system according to claim 10, wherein the filling unit is further configured to be connectable to a power supply unit that supplies power necessary for the filling to the filling unit.

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