JP2010255746A - Gas supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas supply system that reduces the time from the start of start-up to the actual start of operation. <P>SOLUTION: A fuel cell system 1 includes: a hydrogen supply source 21; a hydrogen supply passage 22 for supplying gas from the gas supply source 21 to a fuel cell 2; an injector 28 that adjusts a gas state on the upstream side of the hydrogen supply passage 22 so as to supply gas to the downstream side; an electromagnetic shut-off valve 26 provided between the hydrogen supply source 21 and the injector 28 so as to open/close the hydrogen supply passage 22; and a control part 5 for controlling the drive of the injector 28. The control part 5 starts the drive of the injector 28 after detecting the opening of the shut-off valve 26 on the basis of changes in current supplied to the shut-off valve 26. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a gas supply system that supplies gas to a gas consumption unit.

  Conventionally, for example, a gas supply system for supplying a reaction gas (fuel gas and oxidizing gas) to a fuel cell that generates power by an electrochemical reaction has been proposed and put into practical use. Such a gas supply system is provided with a fuel supply source that stores high-pressure fuel gas, and an injector that is an on-off valve for controlling the supply state of the fuel gas from the fuel supply source (for example, a patent) Reference 1).

JP 2008-275075 A

  In the above system, a shut-off valve and a regulator are provided from the upstream side between the fuel supply source and the injector, the shut-off valve is opened, and after the pressure of the gas is adjusted by the regulator, the operation with the drive of the injector is started. Has started.

  By the way, since the fuel supply source is high-pressure, the shut-off valve has a pilot valve part and a main valve part, and can be opened without difficulty even when the pressure difference between the upstream and downstream is large A solenoid valve may be used. In this shut-off valve, when the pilot valve portion is first opened and the pressure difference between the upstream and downstream is reduced to some extent, the main valve portion is opened.

  Therefore, in such a shut-off valve, when the pressure difference between the upstream and downstream becomes large, such as at the start immediately after filling the fuel gas into the fuel supply source or at the low temperature start in which the fuel consumption increases, this pressure The time until the difference is reduced to a predetermined value, that is, the time until the main valve portion is opened is relatively longer than in other cases.

  However, in a system equipped with such a shut-off valve, the safety timing is taken into consideration when the main valve part of the shut-off valve opens, regardless of the downstream pressure, in the longest time until the main valve part opens as described above. The time obtained by adding the measured time is set as the valve opening time. For this reason, there is a problem that the startup time from the start of the start to the actual start of the operation is unnecessarily long even at the normal start that can start the operation in a shorter time. .

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a gas supply system capable of shortening the time from the start of startup to the actual start of operation.

In order to achieve the above object, a gas supply system of the present invention includes a gas supply source, a gas supply channel for supplying gas from the gas supply source to a gas consumption unit, and an upstream of the gas supply channel. An on-off valve that adjusts the gas state on the side and supplies it to the downstream side, an electromagnetic shut-off valve that is provided between the gas supply source and the on-off valve and opens and closes the gas supply flow path, and the on-off valve In a gas supply system comprising a control unit for controlling the driving of
The controller starts driving the on-off valve after detecting the opening of the shut-off valve based on a change in current supplied to the shut-off valve.

According to the gas supply system having such a configuration, when the shut-off valve is driven, the coil inductance is changed, the magnetic field is changed, and a current is changed in the shut-off valve. And a control part detects that the cutoff valve actually opened based on the electric current change of this cutoff valve, and starts the drive of an on-off valve after that.
As described above, since the control unit detects the actual opening of the shut-off valve from the current change and starts to drive the on-off valve, the valve opening time based on the longest time for the shut-off valve to open is set in advance. Compared with the case where the on-off valve is driven after the valve opening time has elapsed uniformly, the on-off valve driving can be started in a short time without providing a useless delay time according to the start-up conditions.

  In the gas supply system of the present invention, the shut-off valve is a pilot-type solenoid valve that opens the main valve portion when the upstream / downstream differential pressure reaches a predetermined value after the pilot valve portion is opened. Also good.

  In the gas supply system of the present invention, the on-off valve may be an injector that adjusts a gas flow rate or a gas pressure by driving the valve body with an electromagnetic driving force at a predetermined driving cycle and separating the valve body from the valve seat. good.

  In the gas supply system of the present invention, a hydrogen tank as the gas supply source may be provided, and fuel gas may be supplied to a fuel cell as the gas consuming unit.

  In the gas supply system of the present invention, a natural gas tank as the gas supply source may be provided, and natural gas may be supplied to an internal combustion engine as the gas consuming unit.

  According to the gas supply system of the present invention, it is possible to shorten the time from the start to the start of actual operation.

1 is a configuration diagram of a gas supply system (fuel cell system) according to an embodiment of the present invention. It is a graph which shows the relationship between the pressure of the downstream of a cutoff valve, and the electric current value of a cutoff valve.

  Hereinafter, a gas supply system according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, as an example of a gas supply system, a fuel cell system 1 applied to a fuel cell vehicle equipped with a fuel cell that generates power by an electrochemical reaction between a fuel gas and an oxidizing gas will be described. And

First, the configuration of the fuel cell system 1 according to the present embodiment will be described.
A fuel cell system 1 according to this embodiment supplies a fuel cell 2, an oxygen gas piping system 3 for supplying an oxidizing gas (air) to the fuel cell 2, and a fuel gas (hydrogen gas) to the fuel cell 2. A fuel gas piping system 4 and a control unit 5 that performs overall control of the entire system.

  The fuel cell 2 corresponds to the gas consuming part in the present invention, and is composed of, for example, a solid polymer electrolyte type and has a stack structure in which a large number of single cells are stacked. The unit cell of the fuel cell 2 has a pair of separators having an air electrode on one surface of an electrolyte made of an ion exchange membrane, a fuel electrode on the other surface, and further sandwiching the air electrode and the fuel electrode from both sides. have. Fuel gas (hydrogen gas) is supplied to the fuel gas flow path of one separator, and oxidizing gas (air) is supplied to the oxidizing gas flow path of the other separator, and the fuel cell 2 generates electric power by this gas supply.

  The oxygen gas piping system 3 includes an air supply passage 11 for supplying an oxidizing gas to the fuel cell 10 and an air discharge passage 12 for guiding the oxidizing off-gas discharged from the fuel cell 2 to the outside. Yes. The air supply passage 11 is provided with an air compressor (not shown) that takes in the oxidizing gas in the atmosphere and pumps it to the fuel cell 2 side.

  The fuel gas piping system 4 includes a hydrogen supply source 21, a hydrogen supply passage 22 through which hydrogen gas supplied from the hydrogen supply source 21 to the fuel cell 2 flows, and a hydrogen supply passage through which the hydrogen off-gas discharged from the fuel cell 2 flows. 22, a circulation flow path 23 for returning to the junction A <b> 1, a hydrogen pump 24 that pumps the hydrogen off-gas in the circulation flow path 23 to the hydrogen supply flow path 22, and an exhaust drainage flow path that is branched and connected to the circulation flow path 23. 25.

  The hydrogen supply source 21 corresponds to the gas supply source in the present invention, and a high-pressure tank (hydrogen tank) filled with hydrogen gas is employed in the present embodiment. The high-pressure tank is configured to store high-pressure hydrogen gas at a predetermined pressure (for example, 35 MPa or 70 MPa). When a shut-off valve 26 described later is opened, hydrogen gas is released from the hydrogen supply source 21 into the hydrogen supply flow path 22. The hydrogen gas is finally depressurized to about 200 kPa, for example, by the regulator 27 and the injector 28 and supplied to the fuel cell 2.

  The hydrogen supply source 21 is provided with a pressure sensor 21a that detects an internal gas pressure. Information on the gas pressure in the tank detected by the pressure sensor 21 a is used for opening / closing control of the injector 28. The hydrogen supply source 21 is composed of a reformer that generates a hydrogen-rich reformed gas from a hydrocarbon-based fuel and a high-pressure gas tank that stores the reformed gas generated by the reformer in a high-pressure state. May be. Moreover, you may comprise the hydrogen supply source 21 with a hydrogen storage alloy.

  The hydrogen supply channel 22 corresponds to the gas supply channel in the present invention. The hydrogen supply flow path 22 is provided with a shutoff valve 26 that shuts off or allows the supply of hydrogen gas from the hydrogen supply source 21, a regulator 27 that adjusts the pressure of the hydrogen gas, and an injector 28. A primary pressure sensor 41 and a temperature sensor 42 for detecting the pressure and temperature of the hydrogen gas released from the hydrogen supply source 21 are provided on the upstream side of the injector 28.

  A secondary pressure sensor 43 is provided on the downstream side of the injector 28 and on the upstream side of the junction A1 between the hydrogen supply channel 22 and the circulation channel 23. Information on the gas state (temperature, pressure) of the hydrogen gas detected by the temperature sensor 42, the pressure sensor 43, etc. is used for opening / closing control of the injector 28.

  The shut-off valves 26 are provided corresponding to the high-pressure tanks. When a plurality of high-pressure tanks are provided as the hydrogen supply source 21, the shut-off valves 26 are provided corresponding to the respective high-pressure tanks. The shut-off valve 26 may be integrated with the high-pressure tank. For example, an in-tank electromagnetic open / close valve may be employed as the shutoff valve 26.

  The shut-off valve 26 is a pilot solenoid valve having a pilot valve portion and a main valve portion. The shutoff valve 26 is connected to a battery 44 and is driven to open and close using the battery 44 as a power source. An ammeter 45 is connected to the power supply line between the shut-off valve 26 and the battery 44, and the value of the current flowing to the shut-off valve 26 is detected. The ammeter 45 is connected to the control unit 5, and the detected current value is transmitted to the control unit 5.

  When the shut-off valve 26 is opened, high-pressure hydrogen gas is released into the hydrogen supply channel 22 at a high speed and diffuses. As a result, hydrogen gas having a predetermined primary pressure is supplied into the hydrogen supply flow path 22. The temperature of hydrogen gas decreases as the pressure decreases during diffusion. The gas temperature of the hydrogen gas after the temperature drop is detected by the temperature sensor 42 described above. In addition, there is a predetermined correspondence between the temperature of the hydrogen gas discharged into the hydrogen supply flow path 22 and the gas pressure in the high-pressure tank. For this reason, the correspondence between the gas temperature of the hydrogen gas released into the hydrogen supply flow path 22 and the gas pressure in the high-pressure tank can be represented by, for example, a map or a relational expression.

  The regulator 27 is a device that regulates the upstream pressure (primary pressure) to a preset secondary pressure. In this embodiment, a mechanical pressure reducing valve that reduces the primary pressure is employed as the regulator 27. If a plurality of regulators 27 are arranged on the upstream side of the injector 28, the upstream pressure of the injector 28 can be effectively reduced.

  The injector 28 is an electromagnetically driven on-off valve capable of adjusting the gas flow rate and the gas pressure by driving the valve body 52 directly with a predetermined driving cycle with an electromagnetic driving force and separating it from the valve seat. . The injector 28 is disposed on the upstream side of the junction A <b> 1 between the hydrogen supply channel 22 and the circulation channel 23. Also, when a plurality of high-pressure tanks are employed as the hydrogen supply source 21, the injector 28 is disposed downstream of the portion where the hydrogen gas supplied from each high-pressure tank merges.

  An exhaust / drain channel 25 is connected to the circulation channel 23 via a gas / liquid separator 30 and an exhaust / drain valve 31. The gas-liquid separator 30 collects moisture from the hydrogen off gas. The exhaust / drain valve 31 is operated according to a command from the control unit 5 to discharge moisture collected by the gas-liquid separator 30 and hydrogen off-gas (fuel off-gas) containing impurities in the circulation passage 23 to the outside. (Purge). Further, the circulation channel 23 is provided with a hydrogen pump 24 that pressurizes the hydrogen off-gas in the circulation channel 23 and sends it to the hydrogen supply channel 22 side.

  The control unit 5 receives control information such as an accelerator signal (required load) of a vehicle (not shown) and controls the operation of various devices in the system. The control unit 5 is configured by a computer system (not shown). Such a computer system includes a CPU, ROM, RAM, HDD, input / output interface, display, and the like, and various control operations are realized by the CPU reading and executing various control programs recorded in the ROM. .

  Specifically, the control unit 5 calculates the amount of hydrogen gas consumed by the fuel cell 2 (hydrogen consumption amount) based on the operating state of the fuel cell 2 and the required power generation amount, and the downstream position of the injector 28. A target pressure value of hydrogen gas at (a target gas supply pressure to the fuel cell 2) is calculated. Further, the control unit 5 calculates the feedback correction flow rate based on the deviation between the calculated target pressure value and the detected pressure value at the downstream position of the injector 28 detected by the secondary pressure sensor 43, and the hydrogen consumption amount And the feedback correction flow rate are added to calculate the injection flow rate of the injector 28.

And the control part 5 outputs the control signal for implement | achieving the calculated injection flow volume, controls the gas injection time and gas injection timing of the injector 28, and the flow volume of the hydrogen gas supplied to the fuel cell 2 And adjust the pressure.
Further, the control unit 5 determines the opening timing of the shut-off valve 26, and controls the operation of the system with the drive of the injector 28 after detecting the opening of the shut-off valve 26.

  The control unit 5 detects the opening timing of the shutoff valve 26 based on the detection result from the ammeter 45. That is, the control unit 5 detects the valve opening timing based on the current value of the current flowing from the battery 44 to the shutoff valve 26.

  Here, what is shown in FIG. 2 is a graph showing the relationship between the pressure on the downstream side of the shutoff valve 26 and the current value of the shutoff valve 26.

  When power is supplied to the shutoff valve 26, first, the pilot valve portion is opened, and at this time, the pressure on the outlet side of the shutoff valve 26 increases (t1 in FIG. 2). Thereafter, the pressure on the outlet side of the shutoff valve 26 gradually increases, and when the pressure difference between the internal pressure of the hydrogen supply source 21 and the pressure on the outlet side of the shutoff valve 26 reaches a predetermined value, the main valve portion opens and the shutoff valve 26 is opened. The pressure on the downstream side increases again (t2 in FIG. 2).

  The current value of the shut-off valve 26 driven as described above fluctuates because the coil inductance of the solenoid valve 26 changes and the magnetic field changes when the pilot valve unit is opened by supplying power to the solenoid valve 26. (T1 in FIG. 2). Next, the pressure difference between the internal pressure of the hydrogen supply source 21 and the pressure on the outlet side of the shutoff valve 26 becomes a predetermined main valve portion opening setting value. When the main valve portion opens, the coil inductance of the electromagnetic valve 26 changes and the magnetic field is changed. Changes, the current value fluctuates again (t2 in FIG. 2).

As described above, in the shutoff valve 26 composed of the pilot type electromagnetic valve, the current value fluctuates when the pilot valve portion is driven and when the main valve portion is driven.
Therefore, the control unit 5 determines the valve opening timing at which the main valve unit is opened by detecting the fluctuation of the current value that occurs after the power supply to the shutoff valve 26 based on the detection result from the ammeter 45, and thereafter The operation of the system with the drive of the injector 28 is started.

  As described above, according to the fuel cell system 1 that is the gas supply system of the present embodiment, the control unit 5 detects that the cutoff valve 26 has actually opened based on the current change of the cutoff valve 26. Then, the drive of the injector 28 is started.

  As described above, since the control unit 5 detects the actual opening of the shutoff valve 26 from the current change and starts to drive the injector 28, the time taking safety into consideration is added to the longest time for the shutoff valve 26 to open. As compared with the case where the valve opening time is set in advance and the injector 28 is driven uniformly after the valve opening time has elapsed, the driving of the injector 28 can be favorably started according to the conditions at the time of activation.

Here, at the time of normal startup in the fuel cell system 1, the shutoff valve 26 according to the embodiment opens in about 0.2 seconds, for example, but at the time of low temperature startup in which fuel consumption increases, for example, 0.8 seconds. It will be about.
Therefore, in a system that starts up at a preset valve opening time, even during normal startup, operation with driving of the injector 28 is started after 0.8 seconds, which is the longest time from the start of startup. .

  On the other hand, in the fuel cell system 1 of the present embodiment, at the time of normal startup, the operation accompanied by driving of the injector 28 is started after 0.2 seconds when the shutoff valve 26 is actually opened from the start of startup. That is, at the time of normal startup, the time of 0.6 seconds can be shortened from the start of startup to the actual operation.

  There is a specific correspondence between the internal pressure of the hydrogen supply source 21, the pressure on the outlet side of the shutoff valve 26, and the opening degree of the regulator 27 and the shutoff valve 26. Therefore, the control unit 5 stores the correspondence relationship of these pressures in advance as a map, and together with the determination of the valve opening timing based on the change in the current value described above, the main valve unit of the shutoff valve 26 based on the map. In this case, even when the change in the current value is small and the valve opening timing is difficult to grasp, the valve opening timing of the main valve portion of the shutoff valve 26 can be determined smoothly. Can do.

  Moreover, in the above embodiment, although the example which applied this invention to the fuel cell system 1 mounted in a fuel cell vehicle was shown, this invention is applicable to the gas supply system which has another different structure. . For example, the present invention is applied to a gas supply system (which includes a natural gas tank as a gas supply source and supplies natural gas to an internal combustion engine as a gas consumption unit) mounted on a compressed natural gas (CNG) automobile. You can also.

  In the above embodiment, an example in which a fuel cell system (gas supply system) is mounted on a fuel cell vehicle has been shown. However, the present invention can be applied to various moving bodies (for example, robots, ships, airplanes, trains, etc.) other than fuel cell vehicles. A fuel cell system can also be installed. Further, the fuel cell system (gas supply system) may be applied to a stationary power generation system used as a power generation facility for a building (for example, a house, a building, or a factory).

  DESCRIPTION OF SYMBOLS 1 ... Fuel cell system (gas supply system), 2 ... Fuel cell (gas consumption part), 5 ... Control part, 21 ... Hydrogen supply source (gas supply source), 22 ... Hydrogen supply flow path (gas supply flow path), 26: shut-off valve, 28 ... injector (open / close valve).

Claims (5)

A gas supply source, a gas supply channel for supplying gas from the gas supply source to the gas consuming unit, and an on-off valve for adjusting the gas state upstream of the gas supply channel and supplying the gas downstream A gas supply system comprising: an electromagnetic shut-off valve provided between the gas supply source and the on-off valve to open and close the gas supply flow path; and a control unit for controlling driving of the on-off valve.
The control unit is a gas supply system that starts driving the on-off valve after detecting the opening of the shut-off valve based on a change in current supplied to the shut-off valve. The gas supply system according to claim 1,
The shutoff valve is a gas supply system that is a pilot-type solenoid valve that opens the main valve portion when the upstream / downstream differential pressure reaches a predetermined value after the pilot valve portion is opened. The gas supply system according to claim 1 or 2,
The said on-off valve is a gas supply system which is an injector which adjusts a gas flow volume and a gas pressure by driving a valve body with a predetermined drive period with an electromagnetic drive force, and separating from a valve seat. The gas supply system according to any one of claims 1 to 3,
A gas supply system comprising a hydrogen tank as the gas supply source and supplying fuel gas to a fuel cell as the gas consuming unit. The gas supply system according to any one of claims 1 to 3,
A gas supply system comprising a natural gas tank as the gas supply source and supplying natural gas to an internal combustion engine as the gas consuming unit.

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