JP4171391B2 - Shutoff valve open / close state determination system and shutoff valve open / close state determination method - Google Patents

Description

  The present invention relates to a shutoff valve open / close state determination system and a shutoff valve open / close state determination method.

  Fuel gas such as hydrogen gas is generally stored in a tank or the like for trading and use. A fuel gas tank, for example, a hydrogen tank in which hydrogen gas is stored, is connected to a gas consuming device such as a fuel cell that consumes hydrogen gas through a shut-off valve and a pressure reducing valve in use. Then, the hydrogen gas is supplied to the gas consuming device through the open shut-off valve, after being reduced to a predetermined pressure by the pressure reducing valve.

  For example, an in-tank electromagnetic valve is known as the shut-off valve. The in-tank solenoid valve is provided on the upstream side of the pressure reducing valve, and is opened when the gas consuming device is in operation, and is closed when the gas consuming device is stopped. The in-tank solenoid valve not only shuts off the supply of fuel gas when the gas consuming equipment stops, but also closes when a device such as a downstream pipe, flow meter, or gas consuming equipment breaks down to prevent the fuel gas from flowing out. To prevent. Furthermore, shut-off valves such as in-tank solenoid valves are generally electrically controlled by an open / close control device or the like, and are closed by transmitting a close command from the open / close control device to the shut-off valve.

As a technique related to such a shutoff valve and pressure reducing valve, a “safety device for a gas fuel regulator” having a fuel shutoff valve has been proposed (see Patent Document 1).
Japanese Examined Patent Publication No. 7-18384 (page 3, left column, line 10 to right column, line 12, line 1)

  However, as described above, it is impossible to know from the outside whether or not the shut-off valve is actually closed by simply sending a close command to the shut-off valve. There was a problem that an event such as not being detected could not be detected.

  Accordingly, an object of the present invention is to provide a shutoff valve open / close state determination system and a shutoff valve open / close state determination method that can reliably and easily determine the open / close state of the shutoff valve in order to solve the above-described problem. .

As means for solving the above-mentioned problems, the present invention provides a fuel gas supply pipe that communicates a fuel gas supply source and a gas consuming device, and the fuel gas supply from the fuel gas supply source toward the gas consuming device. After a shutoff valve and a pressure reducing valve provided in the pipe in order, a fuel gas pressure detector for detecting the pressure of the fuel gas upstream or downstream of the pressure reducing valve, and a valve closing command to the shutoff valve Shut-off valve open / close state determining means for determining the open / close state of the shut-off valve based on the pressure detected by the fuel gas pressure detector, and the shut-off valve open / close state determining means Until the maximum delay time elapses, it is determined whether or not the pressure decreases. When the pressure decreases, it is determined that the shutoff valve is closed, and the maximum delay time from the valve closing command is determined. Even if If the force is not reduced, it is opened and closed state determination system of the shut-off valve, characterized in that the shut-off valve is configured to determine that the open.

Here, the fuel gas supply source supplies fuel gas. As an example, in the first embodiment and the second embodiment described later, a case where the fuel gas supply source is a hydrogen tank will be described. The present invention is not limited to this, and may be a CNG (Compressed Natural Gas) tank, a high-pressure fuel gas supply pipe through which high-pressure fuel gas circulates, or the like.
The gas consuming device is a device that consumes fuel gas, converts it into another energy, and outputs it. As an example, in the first embodiment and the second embodiment described later, the gas consuming device is a fuel cell. However, the present invention is not limited to this, and other CNG engines may be used.

  According to such a shut-off valve open / close state determination system, after the shut-off valve open / close state determination means has issued a valve closing command to the shut-off valve, the fuel is kept until a predetermined maximum delay time elapses from the valve closing command. Continues to determine whether or not the gas pressure decreases. If the pressure decreases, it is determined that the shut-off valve is closed, and the pressure does not decrease even if the maximum delay time elapses from the valve closing command. In this case, by determining that the shut-off valve is open, it is possible to reliably and easily determine the open / close state of the shut-off valve, that is, whether or not the shut-off valve is actually closed.

Further, the maximum delay time is based on the hysteresis characteristic of the pressure reducing valve is open or closed state determination system of the shielding sectional valve you being a pre said shut-off valve closing state determination time set means.

  According to such an open / close state determination system for the shutoff valve, it is possible to reliably and easily determine whether the shutoff valve is actually closed based on the maximum delay time set by the hysteresis characteristic of the pressure reducing valve. it can.

The maximum delay time is a time until the pressure on the upstream side of the pressure reducing valve decreases to the lower limit operating pressure of the pressure reducing valve, and is set according to the pressure on the upstream side of the pressure reducing valve. which is a closing state determination system that shielding sectional valve to said.

That is, in such a system , the maximum delay time becomes longer as the pressure upstream of the pressure reducing valve is higher. And setting this maximum delay time according to the upstream pressure means that the maximum delay time is set corresponding to the maximum pressure upstream of the pressure reducing valve, as will be described in the second embodiment to be described later. In addition, for example, when the pressure on the upstream side of the pressure reducing valve fluctuates up and down or falls at a predetermined rate, the maximum delay time is set according to the degree of fluctuation and reduction. Means good.
According to such a shut-off valve open / close state determination system, whether or not the shut-off valve is actually closed is reliably and easily determined based on the maximum delay time set in accordance with the pressure upstream of the pressure reducing valve. Can be determined.

Further , the shut-off valve open / close state determining means is a unit in which the pressure change amount (ΔP) per unit time obtained from the pressure detected by the fuel gas pressure detector is preset in the shut-off valve open / close state determining means. If it is a reference pressure change amount (.DELTA.Px) more per hour, the pressure is off state determination system to that barrier sectional valve and determines that decreased.

  According to such a shut-off valve open / close state determination system, the shut-off valve open / close state determining means determines that the pressure change amount (ΔP) per unit time obtained from the pressure detected by the fuel gas pressure detector is When it is equal to or greater than the reference pressure change amount (ΔPx) per unit time preset in the determination means, it is reliably and easily determined whether or not the shut-off valve is actually closed by determining that the pressure has decreased. Can be determined.

Further, a fuel gas supply pipe for communicating the fuel gas supply source and a gas consumption device, and from said fuel gas supply source toward the gas consuming device, shut-off valve and the pressure reducing valve provided in this order to the fuel gas supply pipe A method for determining an open / close state of a shut-off valve in a fuel gas supply system comprising: a first step of issuing a close command to the shut-off valve; and continuing the operation of the gas consuming device after the close command A second step of detecting the fuel gas pressure upstream or downstream of the shutoff valve while consuming fuel gas in the fuel gas supply pipe, and a predetermined maximum delay time from the valve closing command. Until the time elapses, it is determined whether or not the pressure decreases, and when the pressure decreases, it is determined that the shut-off valve is closed, and the maximum delay time elapses from the valve closing command. Even the pressure drops If no, a closed state determination method of the shut-off valve and having a third step determines that the shutoff valve is open.

  According to such an open / close state determination method for the shutoff valve, after the valve closing command to the shutoff valve is made, until the maximum delay time elapses, it continues to determine whether or not the pressure of the fuel gas decreases, When the pressure decreases, it is determined that the shut-off valve is closed, and when the pressure does not decrease even when the maximum delay time has elapsed from the valve closing command, it is determined that the shut-off valve is open. Thus, it can be reliably and easily determined whether or not the shut-off valve is actually closed.

According to the present invention, it is possible to provide a shut-off valve open / close state determination system and a shut-off valve open / close state determination method that can reliably and easily determine the open / close state of the shut-off valve.
That is, by taking into account the maximum delay time from the closing command to the shielding sectional valves, whether the shut-off valve is actually closed, can be determined reliably and easily.
Further, based on the maximum delay time set by the hysteresis characteristic of the pressure reducing valve, the open or closed state of the shut-off valve can be determined reliably and easily.
Furthermore , it can be reliably and easily determined whether or not the shut-off valve is actually closed based on the maximum delay time set according to the pressure on the upstream side of the pressure reducing valve.
Furthermore , by comparing the amount of pressure change by the fuel gas pressure detector with the amount of reference pressure change, it is possible to easily determine the pressure drop and reliably and easily determine the open / close state of the shut-off valve.
In addition , by considering the maximum delay time, the open / close state of the shut-off valve can be reliably and easily determined.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
In the description of each embodiment, the same constituent elements are denoted by the same reference numerals, and redundant descriptions are omitted.

<First Embodiment>
First, the shutoff valve open / close state determination system according to the first embodiment will be described with reference to FIGS. 1 to 5.
In the drawings to be referred to, FIG. 1 is a diagram illustrating an overall configuration of a shutoff valve open / close state determination system according to a first embodiment. 2 is a side sectional view schematically showing the pressure reducing valve shown in FIG. 1. FIG. 2 (a) shows an operating state of the pressure reducing valve, that is, a state in which the pressure reducing valve is open and hydrogen gas can flow. ) Indicates a non-operating state of the pressure reducing valve, that is, a state where the pressure reducing valve is closed and hydrogen gas cannot flow. FIG. 3 shows the amount of hydrogen gas flowing downstream (secondary side) of the pressure reducing valve and the pressure on the secondary side at which the pressure reducing valve operates (this is also referred to as pressure reducing valve operating pressure). It is a graph which shows the relationship. 4 is a graph showing changes in pressure on the primary side and the secondary side when the pressure reducing valve shown in FIG. 2 is used. FIG. 4A is a shutoff valve when the flow rate of hydrogen gas flowing downstream of the pressure reducing valve is reduced. (B) shows the case where the shut-off valve is closed when the flow rate is increased. FIG. 5 is a flowchart showing the operation of the shutoff valve open / close state determination system.

[Shutoff valve open / close state judgment system]
As shown in FIG. 1, the shutoff valve open / close state determination system S1 according to the first embodiment is a fuel cell vehicle (not shown) having a hydrogen tank (fuel gas supply source) 5 and a fuel cell 6 (gas consuming device). The fuel gas supply pipe 10 is connected to the upstream side hydrogen tank 5 and the downstream side fuel cell 6, and is provided on the fuel gas supply pipe 10 from the hydrogen tank 5 toward the fuel cell 6. The shutoff valve 21 and the pressure reducing valve 100, the pressure sensor 41 (fuel gas pressure detector) for detecting the pressure of hydrogen gas upstream of the pressure reducing valve 100, and the shutoff valve open / closed state determination for judging the open / closed state of the shutoff valve 21 And means 70.

[Fuel gas supply piping]
The fuel gas supply pipe 10 is divided by the pressure reducing valve 100 in the first embodiment. That is, the fuel gas supply pipe 10 is composed of the fuel pipe 11 on the upstream side of the pressure reducing valve 100 and the fuel pipe 12 on the downstream side.

[Hydrogen tank]
The hydrogen tank 5 is not particularly limited in the present invention, but is preferably made of stainless steel in consideration of durability and pressure resistance. The hydrogen tank 5 is filled with high-pressure hydrogen gas.

[Fuel cell]
The type of the fuel cell 6 is not particularly limited in the present invention, but in the first embodiment, a solid polymer electrolyte fuel cell (PEFC) is used. The fuel cell 6 has an anode (fuel electrode) -side hydrogen flow path 6 a and a cathode (air electrode) -side oxygen flow path 6 b partitioned inside by a membrane electrode assembly (MEA) 7.
Then, hydrogen gas can be supplied from the upstream hydrogen tank 5 to the hydrogen flow path 6a via the shut-off valve 21, the fuel pipe 11, the pressure reducing valve 100, and the fuel pipe 12 in this order. On the downstream side of the hydrogen flow path 6 a, unreacted hydrogen gas can be discharged via the pipe 61 and the stop valve 62.
An air pump 91 that compresses air containing oxygen gas and a humidifier 92 are disposed on the supply side of the oxygen flow path 6b. Air containing oxygen gas compressed and humidified by these can be supplied to the oxygen flow path 6b. A pipe 94 and a stop valve 95 are arranged in this order on the downstream side of the oxygen flow path 6b so that air containing unreacted oxygen gas can be discharged.

[Shutoff valve]
The shut-off valve 21 is a device for shutting off the supply of hydrogen gas on the most upstream side, and an electromagnetic shut-off valve is used in the first embodiment. The shut-off valve 21 is electrically connected to the shut-off valve open / close state determining means 70 and can be appropriately opened and closed according to a valve opening command and a valve close command from the shut-off valve open / close state determining means 70. However, the operation method of the shut-off valve 21 is not limited to an electromagnetic type, and may be a manual type, for example.

[Pressure reducing valve]
The pressure reducing valve (regulator) 100 lowers the high-pressure hydrogen gas supplied from the primary (upstream) hydrogen tank 5 to a predetermined pressure and supplies it to the secondary (downstream) side. This is an apparatus for preventing damage to devices such as the pipe 12, the fuel cell 6, and the membrane electrode assembly 7. That is, the pressure reducing valve 100 is a device that maintains the pressure of the secondary-side hydrogen gas at a certain constant pressure that is lower than the pressure of the primary-side hydrogen gas. Further, the pressure reducing valve 100 is not only a pressure reducing device but also a device for dynamically controlling the flow rate due to the pressure fluctuation on the primary side.
As such a pressure reducing valve 100, for example, a direct acting pressure reducing valve, a pilot pressure reducing valve, a pressure reducing valve with a check valve, a high relief pressure reducing valve, and the like can be appropriately selected and used.

Here, the pressure reducing valve 100 will be further described with reference to FIG.
As shown in FIG. 2, the pressure reducing valve 100 includes a casing 101, a valve body 105, a diaphragm 108, a connecting rod 109, a compression coil spring 107 that biases the valve body 105, and a compression coil spring that biases the diaphragm 108. 110 and an O-ring 106.

  The casing 101 includes a primary side cylinder 102, a secondary side cylinder 103, and a communication path 104 that allows the primary side cylinder 102 and the secondary side cylinder 103 to communicate with each other. The primary cylinder 102 communicates with the hydrogen tank 5 through the fuel pipe 11. The secondary cylinder 103 communicates with the hydrogen flow path 6 a (see FIG. 1) of the fuel cell 6 through the fuel pipe 12.

The valve body 105 is incorporated in the primary cylinder 102 so as to be slidable in the axial direction of the primary cylinder 102.
The diaphragm 108 is built in the secondary cylinder 103. The diaphragm 108 partitions the secondary cylinder 103 into a gas flow chamber 103a through which hydrogen gas flows and a back pressure chamber 103b through which hydrogen gas cannot enter.
The connecting rod 109 is loosely inserted into the communication path 104 and connects the valve body 105 and the diaphragm 108. Therefore, the valve body 105, the connecting rod 109, and the diaphragm 108 are integrally formed.

  The valve body 105 includes a disc-shaped sheet plate portion 105 a and a guide rod portion 105 b that guides the valve body 105 in the axial direction of the primary side cylinder 102. The compression coil spring 107 is interposed between the sheet plate portion 105a and the casing 101, and urges the sheet plate portion 105a toward the communication path 104.

  The O-ring 106 is provided on the end surface of the primary cylinder 102 on the communication path 104 side. When the valve body 105 is pressed against the communication passage 104 side, the seat plate portion 105a is in close contact with the O-ring 106, thereby shutting off the primary side cylinder 102 and the communication passage 104, that is, the secondary side cylinder 103. It is possible. When shut off in this way, the hydrogen gas supplied from the hydrogen tank 5 to the primary cylinder 102 cannot be supplied to the secondary cylinder 103.

  The compression coil spring 110 is provided on the back pressure chamber 103b side of the diaphragm 108, and urges the diaphragm 108 toward the gas circulation chamber 103a side, that is, the communication path 104 side. In general, the biasing force is adjusted by changing the degree of compression of the compression coil spring 110, and the pressure at which the valve body 105 integrated with the diaphragm 108 opens and closes, that is, the pressure on the secondary side reduced by the pressure reducing valve 100 is set. Is done.

Further, the description of the pressure reducing valve 100 will be continued.
When the operating pressure of the pressure reducing valve 100 is set to a predetermined value, for example, when the hydrogen tank 5 is just attached and the internal pressure on the secondary side is not sufficiently increased, as shown in FIG. The urging force F1 of the compression coil spring acting downwardly exceeds the force F2 acting on the diaphragm 108, which is constituted by the internal pressure of the gas flow chamber 103a of the secondary cylinder 103 and the urging force of the compression coil spring 107, and the diaphragm 108 Is pushed down to the gas circulation chamber 103a side. Then, as shown in FIG. 2A, the valve body 105 connected to the diaphragm 108 is also pushed downward, the seat plate portion 105 a is separated from the O-ring 106, and the hydrogen gas is removed from the primary side cylinder 102. The secondary cylinder 103 is supplied via the communication path 104.

On the other hand, as shown in FIG. 2B, in the valve-closed state in which the seat plate portion 105a of the valve body 105 is in close contact with the O-ring 106 and the primary side cylinder 102 and the secondary side cylinder 103 are shut off. A case where the internal pressure on the secondary side decreases will be described.
When the internal pressure of the hydrogen gas in the gas flow chamber 103a of the secondary cylinder 103 decreases, the compression coil spring 110 causes the diaphragm 108 to resist the force F2 acting upward on the diaphragm 108, as shown in FIG. Push down to the gas distribution chamber 103a side. When the diaphragm 108 is pushed down, the valve body 105 is also pushed down. If it does so, the interruption | blocking by contact | adherence with the sheet | seat board part 105a and the O-ring 106 will also be open | released. When the shut-off is thus opened, hydrogen gas is supplied from the primary side cylinder 102 to the secondary side cylinder 103 via the communication path 104.

  By repeating such an operation of the pressure reducing valve 100, that is, a valve opening state and a valve closing state, hydrogen gas is supplied from the primary side to the secondary side with a reduced pressure to a predetermined pressure. .

  Further, the pressure reducing valve 100 generally has an inherent hysteresis characteristic. The pressure reducing valve 100 is a case where hydrogen gas is continuously consumed on the secondary side due to the hysteresis characteristics, and (A) when the flow rate of the hydrogen gas flowing downstream of the pressure reducing valve 100 is increased, B) Different operating characteristics are exhibited when the flow rate of hydrogen gas flowing downstream of the pressure reducing valve 100 is decreased. The operation characteristic by the hysteresis characteristic of the pressure reducing valve 100 will be described with reference to FIG. Here, a case where the pressure reducing valve 100 is set to a set pressure P0, that is, the pressure on the secondary side will be described.

(A) When the flow rate of hydrogen gas flowing downstream of the pressure reducing valve 100 is increased
When the flow rate of the hydrogen gas flowing downstream of the pressure reducing valve 100 is increased while consuming hydrogen gas on the secondary side of the pressure reducing valve 100, the pressure reducing valve 100 has a substantially convex route R1 downward as shown in FIG. It has a characteristic that it operates (opens) below the pressure of the secondary cylinder 103 (see FIG. 2) as a locus. As the amount of hydrogen gas flowing downstream of the pressure reducing valve 100 increases, the operating pressure of the pressure reducing valve 100 approaches the lower limit operating pressure P1 smaller than the set pressure P0, and finally becomes the lower limit operating pressure P1. It has characteristics.

(B) When the flow rate of hydrogen gas flowing downstream of the pressure reducing valve 100 is reduced On the other hand, when the flow rate of hydrogen gas flowing downstream of the pressure reducing valve 100 is reduced while consuming hydrogen gas on the secondary side of the pressure reducing valve 100, the pressure is reduced. As the valve 100 is closed, the pressure on the secondary side of the pressure reducing valve 100 increases and the flow rate downstream of the pressure reducing valve 100 decreases along the locus of the substantially convex route R2 shown in FIG. . As the amount of hydrogen gas flowing downstream of the pressure reducing valve 100 decreases, the operating pressure of the pressure reducing valve 100 approaches the upper limit operating pressure P2 that is higher than the set operating pressure P0, and eventually becomes the upper limit operating pressure P2. It has the characteristic.

  Returning to FIG. 1, the description of the shut-off valve open / close state determination system S1 will be continued.

[Pressure sensor]
The pressure sensor 41 (fuel gas pressure detector) detects the pressure of hydrogen gas inside the fuel pipe 11 on the upstream side of the pressure reducing valve 100. As such a pressure sensor 41, for example, a metal diaphragm type pressure gauge can be used. The pressure sensor 41 is electrically connected to the shut-off valve open / close state determining means 70, and the shut-off valve open / close state determining means 70 can monitor the pressure of hydrogen gas flowing through the fuel pipe 11.

[Shut-off valve open / close state determination means]
The shut-off valve open / close state determination means 70 includes a reference pressure change amount data storage unit 71, a maximum delay time data storage unit 72, and a shut-off valve open / close state determination unit 73.
The reference pressure change amount data storage unit 71 and the maximum delay time data storage unit 72 are configured from a storage medium such as a hard disk drive. The shut-off valve open / close state determination unit 73 includes a CPU, a ROM, an I / O, and the like.
These are electrically connected to each other so that data can be exchanged freely.

(Reference pressure change data storage unit)
The reference pressure change amount data storage unit 71 stores a determination reference pressure change amount (ΔPx) that serves as a determination reference for the degree of decrease in the hydrogen gas pressure after the shut-off valve 21 is instructed to close. That is, the determination reference pressure change amount (ΔPx) is preset in the shutoff valve open / close state determination means 70. The determination reference pressure change amount (ΔPx) is, for example, a pressure change amount per unit time obtained from a pressure detected by a preliminary test for generating power in the fuel cell 6 in a state where the shutoff valve 21 is completely closed.

(Maximum delay time data storage)
In the maximum delay time data storage unit 72, the maximum delay time (Ta max) when the pressure sensor 41 detects the decrease in the pressure of the hydrogen gas most lately after the closing command to the shut-off valve 21 is given. , Remembered. The maximum delay time (Ta max) is a time set based on the hysteresis characteristic of the pressure reducing valve 100.

The maximum delay time (Ta max) will be further described.
In the first embodiment, as shown in FIG. 1, the pressure sensor 41 is disposed on the primary side (upstream side) of the pressure reducing valve 100.
First, in FIG. 3, for example, when the flow rate of hydrogen gas flowing downstream of the pressure reducing valve 100 is decreased, the shutoff valve 21 is completely closed at the point n where the secondary pressure corresponds to the upper limit operating pressure P2. The case will be described. Here, the time when the shut-off valve 21 is closed is a time T0a shown in FIG. At time T0a, the pressure on the secondary side of the pressure reducing valve 100 is P2. The primary pressure at time T0a is P5.

First, at time T0a, the pressure reducing valve 100 is closed. That is, the sheet plate portion 105a (see FIG. 2) is in close contact with the O-ring 106, and the primary side cylinder 102 and the secondary side cylinder 103 are shut off.
Further, at the time T0a when the shut-off valve 21 is closed, the operating pressure of the pressure reducing valve 100 is affected by the hysteresis characteristic (previous history effect) of the pressure reducing valve 100 as shown by an arrow A1 in FIG. The corresponding upper limit operating pressure P2 is switched to the lower limit operating pressure P1 corresponding to the point m which is the same hydrogen gas amount. Therefore, the pressure reducing valve 100 maintains the closed state until the secondary pressure decreases from P2 to P1 (T1) (see FIG. 4A).

That is, after the time T0a shown in FIG. 4A, the primary pressure P5 does not change until the time T1 and shows a constant value. On the other hand, the pressure on the secondary side is reduced according to the degree of hydrogen gas consumption corresponding to the amount of power generation because hydrogen gas is consumed as the power generation of the fuel cell 6 continues. Then, the pressure on the secondary side drops to P1 (T1), pressure reducing valve 100 is operated, hydrogen gas is supplied sequentially from the primary side to the secondary side. As a result, the pressure on the secondary side does not decrease, and the pressure on the primary side decreases (T1 to T2). Further, after the pressure on the primary side has decreased to the pressure on the secondary side (T2), the pressure reducing valve 100 continues to operate again and opens, and the pressure on the primary side and the secondary side similarly decrease. To do.
That is, the primary side pressure is delayed after the secondary side pressure is reduced to the lower limit operating pressure P1, and the time until the secondary side pressure is reduced to the lower limit operating pressure P1 is expressed as a delay time A. And

  Next, in FIG. 3, for example, the case where the shutoff valve 21 is completely closed at the point m corresponding to the upper limit operating pressure P1 when the flow rate of hydrogen gas flowing downstream of the pressure reducing valve 100 is increased will be described. To do. Here, the time when the shut-off valve 21 is closed is a time T0b shown in FIG. At time T0b, the pressure on the secondary side of the pressure reducing valve 100 is P1, and the pressure on the primary side is P5.

  In such a state, when hydrogen gas is consumed on the secondary side of the pressure reducing valve 100 due to continuation of power generation of the fuel cell 6 and the pressure on the secondary side decreases, the pressure reducing valve 100 sequentially operates and the pressure on the primary side Until the pressure becomes equal to the pressure on the secondary side (time T3), the hydrogen gas pressure does not decrease on the secondary side. The time until the primary side pressure becomes equal to the secondary side pressure is defined as a delay time B.

In summary, as shown in FIG. 4A, when the flow rate of the hydrogen gas flowing downstream of the pressure reducing valve 100 is decreased, the pressure on the secondary side of the pressure reducing valve 100 is lower than the lower limit due to the hysteresis characteristic of the pressure reducing valve 100. After the pressure is reduced to the operating pressure P1 (see FIG. 3) (T1), the pressure reducing valve 100 is operated, and the pressure on the primary side is reduced corresponding to the power generation of the fuel cell 6.
On the other hand, as shown in FIG. 4B, when the flow rate of the hydrogen gas flowing downstream of the pressure reducing valve 100 is increased, the primary side corresponding to the power generation amount of the fuel cell 6 is started immediately after the shutoff valve 21 is closed. The pressure drops.

  Therefore, in the first embodiment, since the pressure sensor 41 is arranged on the upstream side (primary side) of the pressure reducing valve 100, the pressure sensor 41 is delayed by a delay time A after the shut-off valve 21 is closed. In some cases, a decrease in pressure on the primary side of the pressure reducing valve 100 is detected.

  Therefore, the maximum delay time (Ta max) when the pressure drop on the primary side of the pressure reducing valve 100 is most delayed is, for example, based on a preliminary test, as shown in the following equation (1), After the valve is closed, the maximum amount (Qa max) of hydrogen gas consumed in the fuel cell 6 is reduced until the pressure on the secondary side of the pressure reducing valve 100 becomes equal to the lower limit operating pressure P1 of the pressure reducing valve 100. It can be calculated by dividing by the hydrogen gas consumption (Q1) consumed per unit time by power generation of 6.

  Ta max = Qa max / Q1 (1)

  Equation (1) is transformed as shown in the following equation (2).

  Tb max = z × ΔP × V12 / Q1 (2)

  Here, in Expression (2), ΔP is a difference between the lower limit operating pressure P1 and the upper limit operating pressure P2 of the pressure reducing valve 100, and is a value based on a hysteresis characteristic unique to the pressure reducing valve 100. V12 is the volume of the fuel pipe 12, and z is a compression coefficient.

  The maximum delay time (Ta max) calculated in this way is stored in the maximum delay time data storage unit 72 and is preset in the shut-off valve open / close state determination means 70.

(Shut-off valve open / close state determination unit)
The shut-off valve open / close state determination unit 73 has a timer and continues to determine whether or not the pressure of the hydrogen gas decreases until the maximum delay time (Ta max) has elapsed from the close command of the shut-off valve 21. When the hydrogen gas pressure decreases, it is determined that the shut-off valve 21 is closed, and the hydrogen gas pressure does not drop even if the maximum delay time (Ta max) elapses from the shut-off command of the shut-off valve 21 In addition, the shut-off valve 21 is configured to be determined to be open.

[Operation of shutoff valve open / close state determination system S1]
Then, the open / close state determination method for the shutoff valve 21 will be described together with the operation of the shutoff valve open / close state judgment system S1 according to the first embodiment.

The method for determining the open / close state of the shut-off valve 21 includes the first step of issuing a close command to the shut-off valve 21 and the generation of hydrogen in the fuel gas supply pipe 10 by continuing the power generation of the fuel cell 6 after the close command. While consuming gas, the pressure sensor 41 includes a second step of detecting the amount of change in the hydrogen gas pressure upstream of the pressure reducing valve 100 and a third step of determining the open / closed state of the shutoff valve 21.
Here, in the first embodiment, the “fuel gas supply system” in the claims includes a fuel gas supply pipe 10, a shut-off valve 21, and a pressure reducing valve 100.

First, the power generation status of the fuel cell 6 will be briefly described with reference to FIG.
Hydrogen gas decompressed to a predetermined pressure by the pressure reducing valve 100 is continuously supplied from the hydrogen tank 5 to the hydrogen flow path 6 a of the fuel cell 6. Air containing oxygen gas is continuously supplied to the oxygen flow path 6b.
In such a state, when the external circuit 50 is electrically connected, the fuel cell 6 generates power and the electric motor 51 operates. When the fuel cell 6 generates power in this way, hydrogen gas is consumed on the anode side, and oxygen gas in the air is consumed on the cathode side.

  In the first embodiment, when the fuel cell 6 that is generating power is stopped in this way, when the shut-off valve opening / closing state determination means 70 issues a valve closing command to the shut-off valve 21, the shut-off valve 21 actually The case where it is determined whether or not it is closed will be described with reference to FIGS.

(First step)
When the power generation stop of the fuel cell 6 is executed, the shut-off valve open / close state determining means 70 issues a valve close command to the shut-off valve 21 and closes the shut-off valve 21 (S1, Yes). The case where the valve closing command is not issued (S1, No) is the case where the fuel cell 6 is not stopped.

  Further, the valve closing command is issued to the shut-off valve 21, and the shut-off valve open / close state determination unit 73 starts a built-in timer (S2).

(Second step)
Then, the power generation of the fuel cell 6 is continued even after the valve closing instruction to the shutoff valve 21 and the hydrogen gas in the fuel gas supply pipe 10 is consumed.

  The shut-off valve open / close state determination unit 73 reads out and acquires the determination reference pressure change amount (ΔPx) serving as the determination criterion for the open / close state from the reference pressure change amount data storage unit 71 (S3).

  Next, the shut-off valve open / close state determination unit 73 reads and acquires the maximum delay time (Ta max) from the maximum delay time data storage unit 72 (S4).

(Third step)
Therefore, the shut-off valve open / close state determination unit 73 determines the absolute value (hereinafter “| detected pressure change amount”) of the hydrogen gas pressure change amount ΔP (hereinafter referred to as “detected pressure change amount”) per unit time determined by the pressure detected by the pressure sensor 41. | (| ΔP |) ”) and the absolute value of the judgment reference pressure change amount (ΔPx) (hereinafter referred to as“ | judgment reference pressure change amount | (| ΔPx |) ”) The open / close state of the valve 21 is determined (S5).

  Specifically, when “| detected pressure change amount | (| ΔP |)” is equal to or greater than “| judgment reference pressure change amount | (| ΔPx |)” (S5, Yes), the shut-off valve open / close state determination unit 76 determines that the shut-off valve 21 is closed (S6), and ends the open / close state judgment method of the shut-off valve 21.

  On the other hand, if “| detected pressure change amount | (| ΔP |)” is smaller than “| judgment reference pressure change amount | (| ΔPx |)” (S5, No), then the shut-off valve open / close state determining unit 73 Then, the elapsed time T from the valve closing command of the shut-off valve 21 is compared with the aforementioned maximum delay time (Ta max) (S7).

  When the elapsed time T is smaller than the maximum delay time (Ta max), that is, when the maximum delay time (Ta max) has not yet elapsed after the valve closing command of the shut-off valve 21 (S7, No), The shut-off valve open / close state determination means 73 considers the case where the shut-off valve 21 is closed when the flow rate is reduced (see FIG. 4A), and subsequently obtains a “| detection obtained from the pressure newly detected by the pressure sensor 41. The pressure change amount | (| ΔP |) "is compared with" | judgment reference pressure change amount | (| ΔPx |) "(S5).

On the other hand, when the elapsed time T is equal to or greater than the maximum delay time (Ta max), that is, when the maximum delay time (Ta max) has elapsed after issuing the valve closing command for the shut-off valve 21 (S7, Yes). ), The shutoff valve open / close state determination means 76 determines that the shutoff valve 21 is open (S8), and ends the open / close state determination method of the shutoff valve 21.
In addition, when the shut-off valve 21 is not closed in spite of the fact that the shut-off valve 21 is issued in this way, the shut-off valve open / close state determining means 70 provides a warning lamp (warning means). You may make it light.

  Thus, according to the open / close state determination system S1 of the shutoff valve and the open / close state judgment method of the shutoff valve 21, it is possible to reliably and easily determine whether or not the shutoff valve 21 is actually closed. That is, after the shutoff valve 21 is closed, the hysteresis characteristic of the pressure reducing valve 100 determines that the shutoff valve 21 is erroneously opened even if the hydrogen gas pressure on the upstream side of the pressure reducing valve 100 decreases with a delay. There is nothing.

  Further, the open / close state of the shut-off valve 21 can be determined only by providing one pressure sensor 41 on the upstream side of the pressure reducing valve 100. Furthermore, actually, another pressure sensor is provided on the downstream side of the pressure reducing valve 100. However, even when the other pressure sensor fails, the open / close state of the shutoff valve 21 can be determined. .

Second Embodiment
Next, the shutoff valve open / close state determination system according to the second embodiment will be described with reference to FIG. FIG. 6 is an overall configuration diagram of the shutoff valve open / close state determination system according to the second embodiment.

  As shown in FIG. 6, the shutoff valve open / close state determination system S <b> 2 according to the second embodiment is a pressure sensor 41 that detects the pressure of hydrogen gas on the upstream side (primary side) of the pressure reducing valve 100 in the first embodiment. Instead, the main feature is that a pressure sensor 42 for detecting the pressure of the hydrogen gas is provided on the downstream side (secondary side) of the pressure reducing valve 100.

As described above, in the second embodiment, the pressure sensor 42 is arranged on the downstream side (secondary side) of the pressure reducing valve 100, so that the downstream side of the pressure reducing valve 100 flows as shown in FIG. When the shut-off valve 21 is closed when the flow rate of hydrogen gas is reduced (T0a), the pressure on the secondary side decreases corresponding to the amount of power generated by the fuel cell 6, but as shown in FIG. When the shutoff valve 21 is closed when the flow rate of the hydrogen gas flowing downstream of the pressure reducing valve 100 is increased (T0b), the lower limit operating pressure of the pressure reducing valve 100 is such that the primary pressure is the secondary pressure. Since the secondary pressure does not change until it decreases to P1 (T3), it is considered that the delay time B occurs.

  In the maximum delay time data storage unit 72 ′ of the shut-off valve open / close state determining means 70 ′ according to the second embodiment, the maximum delay time (Tb) is used instead of the maximum delay time (Ta max) according to the first embodiment. max) is stored.

  The maximum delay time (Tb max) according to the second embodiment is, for example, as shown in the following equation (3), after the shut-off valve 21 is closed, the pressure on the primary side of the pressure reducing valve 100 is on the secondary side. The maximum amount of hydrogen gas (Qb max) supplied from the primary side to the secondary side of the pressure reducing valve 100 until the pressure becomes equal to the pressure is calculated as the hydrogen gas consumption amount consumed per unit time by the power generation of the fuel cell 6 ( It can be calculated by dividing by Q1).

  Tb max = Qb max / Q1 (3)

  Equation (3) is transformed as shown in the following equation (4).

  Tb max = [z × (P5 max−P1) × V11] / Q1 (4)

  Here, in Expression (4), “P5 max” indicates the maximum pressure on the primary side of the pressure reducing valve 100, P1 indicates the lower limit operating pressure of the pressure reducing valve 100, V11 indicates the volume of the fuel pipe 11, z represents a compression coefficient. In the first embodiment, P5 max corresponds to the pressure of the hydrogen gas sealed in the hydrogen tank 5.

[Operation of shutoff valve open / close state determination system S2]
Then, the determination method of the open / close state of the shut-off valve 21 will be described together with the operation of the shut-off valve open / close state determination system S2 according to the second embodiment.

  In the open / close state determination method of the shutoff valve 21 according to the second embodiment, in step S5 (see FIG. 5) according to the first embodiment, “| detected pressure change amount | (ΔP) obtained from the pressure detected by the pressure sensor 42”. ) "And" | judgment reference pressure change amount | (| ΔPx |) ", and in step S7, the elapsed time T from the shut-off valve closing command is compared with the maximum delay time (Tb max). Then, it is determined whether or not the shut-off valve 21 is actually closed.

  As mentioned above, although an example was demonstrated about each preferred embodiment of this invention, this invention is not limited to each said embodiment, In the range which does not deviate from the meaning of this invention, each component demonstrated by each embodiment is suitably used. They may be combined, and other appropriate changes such as the following are possible.

  In each of the above-described embodiments, the fuel gas supply source is the hydrogen tank 5 and the gas consuming device is the fuel cell 6. However, the present invention is not limited to this. For example, the fuel gas source may be CNG (Compressed Natural Gas). It is good also as a tank and it is good also considering a gas consumption apparatus as a CNG engine. In such a case, the operation output of the CNG engine may be detected from the rotational speed of the CNG engine, and it is assumed that all of the CNG supplied to the CNG engine is consumed. A flow meter may be provided, and the operation output of the CNG engine may be calculated by this flow meter.

  The time obtained by multiplying the maximum delay time (Ta max) according to the first embodiment described above by a safety factor, the operation time of the shut-off valve open / close state determination unit 73, and the closing of the shut-off valve 21 By comparing the elapsed time from the command, the determination accuracy of the open / close state of the shutoff valve 21 may be improved.

  In the first embodiment described above, one pressure reducing valve 100 is provided between the shutoff valve 21 and the fuel cell 6, and the pressure of the hydrogen gas is detected by the pressure sensor 41 provided on the upstream side of the pressure reducing valve 100. However, the present invention is not limited to this, and a plurality of pressure reducing valves may be provided. Thus, when there are a plurality of pressure reducing valves, it is possible to determine whether or not the shutoff valve is actually closed by taking into account the delay of the pressure reducing valve that affects the installation position of the pressure sensor.

  In the first embodiment described above, the cutoff valve 21 and the pressure reducing valve 100 are configured to communicate with each other via the fuel pipe 11, but the cutoff valve 21 and the pressure reducing valve 100 may be integrated. In the case of the integral type as described above, the pipe portion between the shutoff valve and the pressure reducing valve is regarded as the fuel gas supply pipe.

  In the first embodiment described above, the shut-off valve open / close state determination means 70 compares “| detected pressure change amount | (| ΔP |)” with “reference pressure change amount (| ΔPx |)”. The pressure sensor 41 may be configured to determine that the shut-off valve 21 is closed when a pressure drop is detected.

In the second embodiment described above, “P5 max” in Equation (4) is regarded as a constant pressure of the hydrogen gas sealed in the hydrogen tank 5, and the maximum delay is determined according to the pressure of the hydrogen gas regarded as constant. Although the time (Tb max) is calculated, the present invention is not limited to this. For example, there is another pressure sensor on the upstream side of the pressure reducing valve 100, and the pressure on the upstream side of the pressure reducing valve 100 fluctuates up and down. In this case, the maximum delay time (Tb max) may be calculated and set by setting “P5 max” corresponding to the pressure that fluctuates up and down. In such a case, since the maximum delay time (Tb max) is set according to the actual primary pressure, the determination time can be shortened.
Alternatively, the average pressure of the hydrogen gas previously sealed in the hydrogen tank 5 may be estimated, and the maximum delay time (Tb max) may be calculated and set with this average pressure as “P5 max”.

It is a figure which shows the whole structure of the shut-off-valve open / close state determination system which concerns on 1st Embodiment. FIG. 2 is a side sectional view schematically showing the pressure reducing valve shown in FIG. 1, in which (a) shows a state where the pressure reducing valve is open and hydrogen gas can flow, and (b) shows a state where the pressure reducing valve is closed and the hydrogen gas flows. Indicates a state where distribution is not possible. 3 is a graph showing the relationship between the amount of hydrogen gas flowing downstream of the pressure reducing valve and the secondary pressure at which the pressure reducing valve operates for the pressure reducing valve shown in FIG. 2. It is a graph which shows the pressure change of the primary side and secondary side of a pressure-reduction valve after closing of a cutoff valve, (a) is the case where a cutoff valve is closed at the time of the flow volume reduction of the hydrogen gas which circulates downstream of a pressure-reduction valve (B) shows the case where the shut-off valve is closed when the flow rate is increased. It is a flowchart which shows operation | movement of the shut-off-valve open / close state determination system which concerns on 1st Embodiment. It is a figure which shows the whole structure of the shut-off-valve open / close state determination system which concerns on 2nd Embodiment.

Explanation of symbols

S1, S2 Shutdown valve open / close state determination system 5 Hydrogen tank (fuel gas supply source)
6 Fuel cell (gas consuming equipment)
DESCRIPTION OF SYMBOLS 10 Fuel supply piping 21 Shut-off valve 41, 42 Pressure sensor 70, 70 'Shut-off valve open / close state determination means 71 Reference pressure change amount data storage part 72, 72' Maximum delay time data storage part 73 Shut-off valve open / close state determination part 100 Pressure reducing valve

Claims (5)

A fuel gas supply pipe communicating the fuel gas supply source and the gas consuming device;
A shutoff valve and a pressure reducing valve provided in order on the fuel gas supply pipe from the fuel gas supply source toward the gas consuming device,
A fuel gas pressure detector for detecting the pressure of the fuel gas upstream of the pressure reducing valve;
A shut-off valve open / close state determining means for determining the open / close state of the shut-off valve based on the pressure detected by the fuel gas pressure detector after a valve closing command to the shut-off valve is made;
The shut-off valve open / close state determining means includes
Until the predetermined maximum delay time elapses from the valve closing command, it is determined whether or not the pressure decreases, and when the pressure decreases, it is determined that the shutoff valve is closed,
Even if the maximum delay time elapses from the valve closing command, when the pressure does not decrease, it is determined that the shutoff valve is open ,
The maximum delay time is a time set in advance in the shut-off valve open / close state determination means based on the hysteresis characteristic of the pressure reducing valve, and the secondary pressure decreases from the upper limit operating pressure of the pressure reducing valve to the lower limit operating pressure. It is time to do
Closing state determination system of the shut-off valve characterized by the this. A fuel gas supply pipe communicating the fuel gas supply source and the gas consuming device;
A shutoff valve and a pressure reducing valve provided in order on the fuel gas supply pipe from the fuel gas supply source toward the gas consuming device,
Under downstream of the pressure reducing valve, and the fuel gas pressure detector which detects the pressure of the fuel gas,
A shut-off valve open / close state determining means for determining the open / close state of the shut-off valve based on the pressure detected by the fuel gas pressure detector after a valve closing command to the shut-off valve is made;
The shut-off valve open / close state determining means includes
Until the predetermined maximum delay time elapses from the valve closing command, it is determined whether or not the pressure decreases, and when the pressure decreases, it is determined that the shutoff valve is closed,
Even if the maximum delay time elapses from the valve closing command, when the pressure does not decrease, it is determined that the shutoff valve is open ,
The maximum delay time is a time until the pressure on the upstream side of the pressure reducing valve decreases to the lower limit operating pressure of the pressure reducing valve, and is set according to the pressure on the upstream side of the pressure reducing valve. Open / close state judgment system for shutoff valve The shut-off valve open / close state determining means is configured such that a pressure change amount (ΔP) per unit time obtained from the pressure detected by the fuel gas pressure detector is calculated per unit time preset in the shut-off valve open / close state determining means. closing state determination system of the shut-off valve according to claim 1 or claim 2 in the case where the reference pressure change amount (.DELTA.Px) above, wherein the pressure is and determines that the lowering of. A fuel gas supply pipe that communicates the fuel gas supply source and the gas consuming device, and a shutoff valve and a pressure reducing valve that are sequentially provided in the fuel gas supply pipe from the fuel gas supply source to the gas consuming device. A method for determining the open / close state of a shutoff valve in a fuel gas supply system comprising:
A first step of issuing a valve closing command to the shutoff valve;
After the valve closing instruction, by continuing the operation of the gas consuming device, while consuming the fuel gas in the fuel gas supply pipe,
A second step of detecting the pressure of the fuel gas upstream of the shutoff valve;
From the valve closing command, until a predetermined maximum delay time elapses, it is determined whether or not the pressure decreases, and when the pressure decreases, it is determined that the shutoff valve is closed,
A third step of determining that the shut-off valve is open when the pressure does not decrease even after the maximum delay time has elapsed from the valve closing command;
I have a,
The maximum delay time is a time set in advance in the shut-off valve open / close state determination means based on the hysteresis characteristic of the pressure reducing valve, and the secondary pressure decreases from the upper limit operating pressure of the pressure reducing valve to the lower limit operating pressure. A method for determining the open / close state of a shut-off valve, characterized in that it is the time until A fuel gas supply pipe that communicates the fuel gas supply source and the gas consuming device, and a shutoff valve and a pressure reducing valve that are sequentially provided in the fuel gas supply pipe from the fuel gas supply source to the gas consuming device. A method for determining the open / close state of a shutoff valve in a fuel gas supply system comprising:
A first step of issuing a valve closing command to the shutoff valve;
After the valve closing instruction, by continuing the operation of the gas consuming device, while consuming the fuel gas in the fuel gas supply pipe,
Under downstream of the shut-off valve, and a second step of detecting a pressure of the fuel gas,
From the valve closing command, until a predetermined maximum delay time elapses, it is determined whether or not the pressure decreases, and when the pressure decreases, it is determined that the shutoff valve is closed,
A third step of determining that the shutoff valve is open when the pressure does not decrease even after the maximum delay time has elapsed from the valve closing command;
I have a,
The maximum delay time is a time until the pressure on the upstream side of the pressure reducing valve decreases to the lower limit operating pressure of the pressure reducing valve, and is set according to the pressure on the upstream side of the pressure reducing valve. A method for determining the open / close state of the shut-off valve.

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