JP2003308868A - Gas fuel supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas fuel supply device allowing failure diagnosis of a shut-off valve in a short time. <P>SOLUTION: A fuel is supplied from a fuel tank 2 to a fuel cell 1 via fuel supply line 4 having the shut-off valve 3 and a pressure sensor 5 in sequence, the shut-off valve 3 is opened in accordance with a failure diagnosis signal and a percentage of pressure drop is calculated in accordance with pressure information from the pressure sensor 5 and the passage of time to determine the condition of a failure of the shut-off valve 3. In this case, an electric power consuming part 11 consumes electric power generated by the fuel cell 1 to increase a target percentage of fuel consumption C1, thus permitting determination of the condition of the failure in a short time. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas fuel supply system capable of diagnosing a failure state of a shutoff valve.

[0002]

2. Description of the Related Art Conventionally, in order to diagnose a failure state of a shutoff valve, a shutoff valve and a pressure sensor are arranged in this order in a pipe between a fuel tank and a fuel consuming device such as an engine, and the shutoff valve is closed. It is known that the failure diagnosis of the shutoff valve is performed by the pressure after a predetermined time, for example, Japanese Patent Laid-Open No. 2000-2743.
No. 11 publication.

This is because the shut-off valve is closed while the vehicle is stopped or operating, and the amount of pressure decrease after a predetermined time or the elapsed time until the pressure decreases to a predetermined pressure is measured to determine the pressure decrease rate. It is calculated and compared with the threshold value of the pressure drop rate to diagnose the failure of the shutoff valve.

[0004]

By the way, the rate of decrease in pressure downstream of the shutoff valve changes depending on the operating state of the vehicle, that is, the fuel consumption rate of the fuel consuming device.

However, in the above-mentioned conventional example, the shutoff valve is closed, and the pressure drop amount after a predetermined time or the time elapsed until the pressure drops to the predetermined pressure is measured to perform the failure diagnosis of the shutoff valve. ing. Therefore, when the fuel consumption rate is low depending on the operating state of the vehicle, it takes time to reduce the pressure.

When the diagnosis is made by the pressure decrease amount after a predetermined time, the lower limit pressure decrease amount is determined from the detection accuracy and resolution of the pressure sensor, and the set predetermined time is set to be equal to or longer than the time when the pressure decreases by the lower limit pressure decrease amount. Since it is indispensable, there is a problem that it takes time to perform a failure diagnosis.

Further, when the time elapsed until the pressure drops to the predetermined pressure is measured, the predetermined pressure must be equal to or less than the value obtained by subtracting the lower limit pressure decrease amount from the fuel tank pressure, so that the fuel consumption rate is low. However, there is a problem that it takes time to reduce the pressure to a predetermined pressure and it takes time to perform a failure diagnosis.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a gas fuel supply apparatus capable of performing failure diagnosis of a shutoff valve in a short time.

[0009]

According to a first aspect of the present invention, fuel is supplied from a fuel supply means to a fuel consuming means, a fuel supply line having a shutoff valve and a pressure sensor, and the shutoff valve based on a failure diagnosis signal. The valve is closed, the pressure decrease rate is calculated based on at least the pressure information from the pressure sensor and the elapsed time, and when the pressure decrease rate is smaller than a predetermined pressure decrease rate threshold value, the shutoff valve fails. In a gas fuel supply device having a failure detection means for judging that the state is a state, under the condition that the failure detection means operates based on the failure diagnosis signal, the target fuel consumption rate consumed by the fuel consumption means is increased. It is characterized by comprising a fuel consumption control means for controlling.

In the fuel cell vehicle, the fuel consuming means is a fuel cell that consumes fuel gas or a combustor that burns the fuel gas. The fuel consumption control means is the target fuel consumption of these fuel cells and combustor. The rate is increased and controlled under the condition that the fault detection means operates.

A second invention is characterized in that, in the first invention, in addition to the fuel consuming means, an energy storage means for storing energy obtained by the fuel consumed at the time of executing the failure diagnosis of the shutoff valve is provided.

A third invention is characterized in that, in the second invention, the energy storage means adjusts the energy storage amount before a failure diagnosis of the shutoff valve.

In a fourth aspect based on the first to third aspects, the fuel supply means is a hydrogen tank for storing hydrogen-rich gas fuel, the fuel consuming means is a fuel cell, and the energy is The storage means is a power storage means.

In a fifth aspect based on the fourth aspect, the failure detecting means adjusts the state of charge of the power storage means in accordance with the generated power calculated from the amount of hydrogen required for diagnosis. .

In a sixth aspect based on the first aspect, the fuel consuming means includes auxiliary fuel consuming means in parallel, and the fuel supply line supplies fuel to the fuel consuming means and the auxiliary fuel consuming means. It is characterized in that it is provided with a fuel supply ratio control means for controlling the ratio.

A seventh invention is characterized in that, in the sixth invention, the auxiliary fuel consuming means comprises a combustor.

[0017]

Therefore, according to the first aspect of the present invention, the failure detecting means can increase and control the fuel consumption amount of the fuel consuming means, so that the fuel consumption amount of the fuel consuming means can be controlled when diagnosing the failure of the shutoff valve. By adjusting the pressure, the pressure of the fuel supply line can be reduced in a shorter time, and the failure diagnosis of the shutoff valve can be performed in a shorter time.

In the second invention, in addition to the effect of the first invention, the energy obtained by extra for the failure diagnosis of the shut-off valve is stored in the energy storage means, so that the failure diagnosis can be further performed without wasting the fuel. It can be done in a short time.

In the third invention, in addition to the effect of the second invention, since the storage amount of the energy storage means is adjusted before the failure diagnosis of the shut-off valve, the energy storage means is adjusted according to the energy obtained by the failure diagnosis. It is possible to store the excess amount of energy obtained by the failure diagnosis in the energy storage means by reducing the storage amount of, and to perform the failure diagnosis without wasting energy.

In the fourth invention, in addition to the effects of the first to third inventions, the generated power of the fuel cell that consumes hydrogen gas fuel at the time of failure diagnosis of the shutoff valve is stored in the power storage means. The failure diagnosis of the shutoff valve can be carried out without wasting.

In addition to the effect of the fourth aspect of the invention, the fifth aspect of the invention adjusts the state of charge of the power storage means in accordance with the generated power calculated from the amount of hydrogen required for the diagnosis, so that power is generated by failure diagnosis. The power storage means can be charged without wasting power.

In the sixth invention, in addition to the effect of the first invention, the fuel supply ratio control means supplies fuel to the fuel consumption means and the auxiliary fuel consumption means according to the target fuel consumption rate and the fuel consumption rate of the fuel consumption means. When the fuel consumption rate of the fuel consuming means is not sufficient for the target fuel consumption rate, the fuel can be consumed at the target fuel consumption rate by supplying the fuel to the auxiliary fuel consuming means. it can.

In addition to the effect of the sixth aspect of the invention, the seventh aspect of the present invention comprises the combustor as the auxiliary fuel consuming means, so that even when the fuel consuming means cannot sufficiently consume the gas fuel,
Since the combustor consumes the gas fuel by the fuel supply ratio control means, the fuel can be consumed at the target fuel consumption rate even when the fuel consumption means cannot sufficiently consume hydrogen.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment for realizing a gas fuel supply system according to the present invention will be described based on a first embodiment corresponding to claim 1.

(First Embodiment) FIGS. 1 to 4 show an example of a gas fuel supply apparatus according to the first embodiment of the present invention. FIG. 1 is a system configuration diagram, and FIGS. The control flowchart of a diagnosis is shown. The fuel cell and the gas fuel supply device described below are devices mounted on a moving body such as a fuel cell vehicle.

In FIG. 1, the gas fuel supply device mainly comprises a fuel tank 2 as a fuel supply means filled with a hydrogen storage alloy, and an electric fuel supplied from the fuel tank 2 with a gas fuel and an oxidant gas. A fuel cell 1 as a fuel consuming means for generating electric power by a chemical reaction, a power consuming portion 11 such as a motor / inverter to which the electric power of the fuel cell 1 is supplied, and a safe and efficient operation of the fuel cell 1. And a controller 6 for the purpose of doing so.

The fuel tank 2 stores hydrogen stored in a hydrogen storage alloy as gas fuel. The gas fuel from the fuel tank 2 can be supplied to the fuel cell 1 via a shutoff valve 3 with a backflow prevention function and a fuel supply line 4 made of piping, and the shutoff valve 3 is opened / closed to control the supply amount.

The controller 6 comprises a fuel consumption control section 71 as fuel consumption control means and a failure detection section 61 as failure detection means. The fuel consumption control unit 71
During normal operation of the fuel cell 1, the target power generation amount of the fuel cell 1 is calculated based on the power consumption amount consumed by the power consumption unit 11, the fuel consumption rate of the fuel cell 1 is calculated, and the required shutoff valve 3
The valve opening degree (fully closed or fully open) is output to the failure detection unit 61 to open / close the shutoff valve 3. Fuel consumption control unit 71
In addition, at the time of failure diagnosis, the target power generation rate is calculated from the target fuel consumption rate C1 defined by the failure detection unit 61 and the fuel consumption rate of the fuel cell 1 input from the fuel cell 1 and output to the fuel cell 1. The target power consumption amount is output to the power consumption unit 11.

A pressure signal from a pressure sensor 5 for detecting the pressure in the pipe of the fuel supply line 4 downstream of the shutoff valve 3 is input to the failure detection unit 61. Failure detection unit 61
Controls the opening / closing of the shutoff valve 3 according to the opening signal from the fuel consumption control unit 71 during the normal operation of the fuel cell 1. During normal operation of the fuel cell, the supply amount is controlled continuously (linearly) by a regulator valve (not shown). The failure detection unit 61 also calculates and sets the target fuel consumption amount C1, the predetermined time t0, and the pressure drop threshold value a0 at the time of the failure diagnosis, and outputs the calculated fuel consumption amount control unit 71 to the fuel consumption amount control unit 71. The operation of 11 is controlled to reach the target fuel consumption amount C1. Further, the shutoff valve 3 is closed, and the failure of the shutoff valve 3 is determined by the pressure signal from the pressure sensor 5 after the shutoff.

Next, the detailed procedure of the failure diagnosis of the first embodiment will be explained based on the flow charts of FIGS.
Steps 100 to 150 shown in FIG. 2 are for setting conditions for failure diagnosis, steps 220 to 240 shown in FIG. 3 are operations for the fuel consumption control section 71, and steps 300 to 38 shown in FIG.
0 indicates the operation of the failure diagnosis, respectively.

To set the conditions for failure diagnosis, first, step 1
At 00, it is determined whether or not a failure diagnosis signal is issued to the failure detection unit 61. If not issued, step 100
And wait until the failure diagnostic signal is issued. If the failure diagnosis signal has been issued, the process proceeds to step 110.

In step 110, the target fuel consumption rate C1
Is set and the process proceeds to step 120. Target fuel consumption rate C1
As shown in FIG. 5, when the fuel consumption rate of the conventional fuel cell 1 is C0, the elapsed time for consuming the specified hydrogen amount n is tlong. In the present invention, the fuel consumption rate is set to C so that the time for consuming the hydrogen amount n becomes shorter.
By setting the target fuel consumption rate C1 larger than 0, the specified hydrogen amount n can be consumed in the time t0 shorter than tlong. Therefore, the target fuel consumption rate is set to C1.

The specified hydrogen amount n is the amount of hydrogen that must be consumed because the detection value of the pressure sensor 5 changes from P0 to P1. That is, the volume of the fuel supply line 4 from the shutoff valve 3 to the fuel cell 1 is Vpipe, R is a gas constant,
If T is the absolute temperature of the gas fuel, n0 is the amount of hydrogen when the pressure is the initial pressure P0, and n1 is the amount of hydrogen when the pressure is P1, then P0 · Vpipe = n0 · R · T P1 · Vpipe = n1 · R -Since it becomes T, the amount n of hydrogen which must be consumed is: n = n0-n1 = (1-P1 / P0) n0 = (1-P1 / P0) P0 * Vpipe / (R * T) = ( It becomes P0-P1) Vpipe / (R · T).

Here, the pressure decrease amount (P0-P1) = ΔP
Is determined by the detection range and resolution of the pressure sensor 5, the pressure difference ΔP that can be sufficiently identified by the pressure sensor 5 is determined. Therefore, the pressure decrease amount (P0-P1) can be set to be equal to or greater than the pressure difference ΔP. Good.

At step 120, a predetermined time t0 is set and the routine proceeds to step 130. The predetermined time t0 corresponds to the consumption time when the hydrogen amount n is consumed at the target fuel consumption rate C1. That is, when the fuel consumption rate C1 is determined, the amount of hydrogen consumed at the fuel consumption rate C1 is (P0-P1) Vpipe.
The time becomes / (RT). FIG. 6 shows the relationship between the pressure detected by the pressure sensor 5 and the time after the shutoff valve 3 is closed. At time 0, a close command is output to the shutoff valve 3, and the pressure decrease rate a1 from the pressure decrease amount (P0-P1) until the predetermined time t0 elapses.
To calculate.

At step 130, the pressure drop rate threshold value a0 is set, and the routine proceeds to step 140. The pressure drop rate threshold value a0 can be calculated from the target fuel consumption rate C1 by calculating the theoretical pressure drop rate when the shutoff valve 3 is completely closed, and it can be determined that the shutoff valve 3 is not out of order. The pressure drop rate threshold value a0 is calculated in consideration of the width of the above. It should be noted that an experiment may be performed using the broken shut-off valve 3, the pressure drop rate at the time of failure may be measured, and the pressure drop rate threshold value a0 may be calculated. In this way, the failure detection unit 61 calculates the above-described target fuel consumption rate C1 and outputs it to the fuel consumption amount control unit 71.

In step 140, the fuel consumption control unit 7
The target power generation amount is set by 1, and the process proceeds to step 150. The target power generation amount is calculated from the target fuel consumption rate C1 input from the failure detection means 61 and the fuel consumption rate of the fuel cell 1 input from the fuel cell 1.

In step 150, a target power consumption amount for causing the power consumption portion 11 to consume the power generation amount generated in the fuel cell 1 is set, and the process proceeds to step 220 in the flowchart of the fuel consumption amount control portion 71 in FIG.

In step 220 of starting the operation of the fuel consumption control unit 71, the target power generation amount is adjusted so that the fuel cell 1 consumes hydrogen at the target fuel consumption rate C1.
Output to step 230.

In step 230, the target power consumption amount is adjusted so that the power consumption unit 11 consumes the power generated by the fuel cell 1, and the fuel consumption amount control unit 71 causes the power consumption unit 11 to operate.
The target power consumption is output to and the process proceeds to step 240.

In step 240, it is determined whether the difference between the fuel consumption rate of the fuel cell 1 and the target fuel consumption rate C1 is within a predetermined range. If it is within the range, the process proceeds to step 300 in the flowchart of the failure diagnosis operation of FIG. If it is out of the range, steps 220 to 230 are repeated to adjust the difference between the fuel consumption rate of the fuel cell 1 and the target fuel consumption rate C1 to be within a predetermined range.

Step 3 for starting the failure diagnosis operation of FIG.
At 00, the failure detection unit 61 issues a close command to the shutoff valve 3,
Go to step 310. In FIG. 6, the time is 0.

In step 310, the gas fuel pressure P0 downstream of the shutoff valve 3 in the fuel supply line 4 is detected by the pressure sensor 5, and the process proceeds to step 320.

In step 320, it is determined whether or not a predetermined time t0 has elapsed since the close command was issued to the shutoff valve 3. If it has elapsed, the process proceeds to step 330, and if it has not elapsed, it waits until the predetermined time t0 elapses. See time point t0 in FIG.

In step 330, the gas fuel pressure P1 of the fuel supply line 4 downstream of the shutoff valve 3 after the elapse of the predetermined time t0 is detected by the pressure sensor 5, and the process proceeds to step 340.

At step 340, (P0-P1) / t
The pressure decrease rate a1 is calculated from 0, and the process proceeds to step 350.

In step 350, it is determined whether the pressure decrease rate a1 calculated in step 340 is smaller than a predetermined pressure decrease rate threshold value a0. If it is smaller, proceed to step 360, and if it is not smaller, step 370.
Go to.

In step 360, the pressure decrease rate a1 is smaller than the pressure decrease rate threshold value a0, so that the shutoff valve 3 does not completely shut off the gas fuel but supplies the gas fuel to the fuel cell 1. Then, the shutoff valve failure flag is set, and the routine proceeds to step 380.

In step 370, since the pressure reduction rate a1 is not smaller than the pressure reduction rate threshold value a0, it is judged that the shutoff valve 3 shuts off the gas fuel, the shutoff valve failure flag is cleared, and the routine proceeds to step 380. move on.

At step 380, the routine proceeds to a failure handling routine (not shown). When the shutoff valve failure flag is set, the system is stopped and failure processing is performed, such as notifying the driver that there is a failure, and the process proceeds to the next step and ends.

By performing the processing as described above, the failure diagnosis of the shutoff valve 3 can be performed in a shorter time.

In order to shorten the diagnosis time t0,
We want P1 to be larger and closer to P0, so P1 is P
It is desirable to set it to 0-ΔP.

In this embodiment, the fuel consumption control section 71 as the fuel consumption control means consumes the fuel at the target fuel consumption rate C1 calculated by the failure detection section 61 as the failure detection means. In order to control the fuel consumption means 11 as described above, when the failure diagnosis of the shutoff valve 3 is performed, the fuel consumption of the fuel cell 1 as the fuel consumption means is adjusted,
The pressure of the fuel supply line 4 can be reduced in a shorter time, and the failure diagnosis of the shutoff valve 3 can be performed in a shorter time.

(Second Embodiment) Hereinafter, an embodiment for realizing the gas fuel supply system according to the present invention will be described in claims 6 and 7.
Will be described based on the second embodiment.

7 to 9 show an example of a gas fuel supply apparatus according to the second embodiment of the present invention. The first embodiment is the gas fuel supplied to the combustor and the fuel cell using the gas fuel. And a fuel supply ratio control unit for branching and supplying the fuel to the combustor. FIG. 7 is a system configuration diagram, and FIGS. 2, 8 and 9 are control flowcharts for failure diagnosis.

In FIG. 7, reference numeral 9 denotes a combustor for combusting a gas fuel, which is diverted from the fuel supply line 4 to the fuel cell 1 by the fuel supply ratio controller 10 and supplied. The combustor 9 is activated by an activation signal from the fuel consumption rate control unit 72. Fuel supply line 4 is fuel tank 2
A shutoff valve 3, a pressure sensor 5, and a fuel supply ratio controller 10 are provided in this order between the fuel cell 1 and the fuel cell 1. The fuel supply ratio controller 10 adjusts the ratio of the gas fuel supplied to the fuel cell 1 and the combustor 9 according to the target fuel supply ratio command input from the fuel consumption controller 72. That is, the fuel consumption control unit 72 outputs a target fuel supply ratio command to the fuel supply ratio control unit 10, outputs a target power generation amount command to the fuel cell 1, outputs a start signal to the combustor, and the power consumption unit 11 Output the target power consumption to.

Next, the detailed procedure of the failure diagnosis of the second embodiment will be described with reference to the flow charts of FIGS. Steps 100 to 150 shown in FIG. 2 are for setting conditions for failure diagnosis, steps 211 to 271 shown in FIG. 8 are operations of the fuel consumption control unit 72, and steps 400 to 400 shown in FIG.
Reference numerals 490 respectively indicate the operation of the failure diagnosis.

Steps 100 to 150 shown in FIG. 2 have already described the condition setting for failure diagnosis, and the operation of the fuel consumption control unit 72 shown in FIG. 8 will be described in the order of steps 211 to 271.

Step 2 of the operation of the fuel consumption controller 72
In step 11, the target fuel supply ratio is adjusted and step 221
Go to. The initial value of the target fuel supply ratio is 1 for the fuel cell 1.
00% and 0% in the combustor. When the process reaches Step 211 via Step 251, the target fuel supply ratio is adjusted so that the fuel consumption amount matches the target fuel consumption amount. The adjustment amount is calculated by mapping the relationship between the fuel consumption amount and the target fuel supply ratio in advance through experiments or the like.

At step 221, the target fuel consumption rate C1
Then, the target power generation amount is adjusted so that the fuel cell 1 consumes hydrogen, and the routine proceeds to step 231. When the combustor 9 is activated, the target power generation amount is adjusted according to the target fuel consumption rate C1 and the hydrogen amount supplied to the fuel cell 1.

In step 231, the power consuming unit 1 consumes the power generated by the fuel cell 1 in order to consume the power.
The target power consumption in 1 is adjusted and the process proceeds to step 241.
When the combustor 9 is activated, the target power consumption amount is adjusted according to the amount of hydrogen supplied to the fuel cell 1.

In step 241, it is determined whether the fuel consumption rate of the fuel cell 1 is smaller than the target fuel consumption rate C1. If it is smaller, the process proceeds to step 251, and if it is not smaller, the process proceeds to step 271.

In step 271, it is determined whether the fuel consumption rate of the fuel cell 1 is larger than the target fuel consumption rate C1. If it is larger, the process proceeds to step 221, and if it is not larger, the process proceeds to step 400, which is the operation of the failure diagnosis shown in FIG.

At step 251, a start signal is output to the combustor 9 and the routine proceeds to step 211.

The judgments in steps 241 and 271 are made by giving an appropriate range to the branch condition. Specifically, when comparing the fuel consumption rate C and the target fuel consumption rate C1, an appropriate range ΔC> 0 is set, and in step 241, if (C1 <C + ΔC) is satisfied, the process proceeds to step 271. In step 271, if (C1> C-ΔC) is satisfied, step 40 which is the operation of the failure diagnosis shown in FIG.
Go to 0.

In the failure diagnosis operation shown in FIG. 9, the failure diagnosis operation shown in FIG. 4 measures the pressure drop amount when a predetermined time t0 has elapsed to perform the failure diagnosis of the shutoff valve 3. The failure time of the shutoff valve 3 is diagnosed by measuring the elapsed time t1 when the pressure detected by the pressure sensor 5 decreases to a predetermined pressure P2.

The details of the failure diagnosis method will be described with reference to FIG. The thick line in FIG. 10 is a diagram showing the relationship between the pressure detected by the pressure sensor 5 and time. At time 0, the shutoff valve 3 is instructed to close, and the elapsed time t1 until the detection value of the pressure sensor 5 reaches a predetermined pressure P2 is measured. The failure diagnosis of the shutoff valve 3 is performed by comparing the elapsed time t1 with the time required for the pressure to change from P0 to the predetermined pressure P2 by the pressure decrease rate threshold value a0.

Returning to FIG. 9, the operation of failure diagnosis will be described with reference to the flowchart.

In step 400, the failure detector 61 outputs a close command to the shutoff valve 3.

In step 410, the gas fuel pressure P0 of the fuel supply line 4 downstream of the shutoff valve 3 is detected, and the measurement of the gas fuel pressure P1 detected by the pressure sensor 5 is started every moment.

At step 420, the measurement of the elapsed time t1 from the output of the close command to the shutoff valve 3 is started.

In step 430, it is determined whether or not the gas fuel pressure P1 detected by the pressure sensor 5 every moment is smaller than a predetermined diagnostic stop pressure P2. If it is smaller, proceed to step 440, and if it is not smaller, step 43.
Go to 0. It is more effective to set the diagnostic stop pressure P2 to a larger value within a range where the pressure sensor 5 can be sufficiently identified, because the time required for the diagnosis is reduced. Therefore, the diagnostic stop pressure P2 is set from the gas fuel pressure P0 downstream of the shutoff valve 3 and the resolution and detection range of the pressure sensor 5.

In step 440, the measurement of the elapsed time t1 from the output of the closing command to the shutoff valve 3 until the gas fuel pressure P1 detected by the pressure sensor 5 momentarily falls below the diagnostic stop pressure P2 is stopped. .

At step 450, (P0-P2) / t
The pressure decrease rate a2 is calculated from 1.

At step 460, it is determined whether the pressure decrease rate a2 calculated at step 450 is smaller than a predetermined pressure decrease rate threshold value a0. If it is smaller, the process proceeds to step 470, and if it is not smaller, the process proceeds to step 480.

At step 470, since the pressure decrease rate a2 is smaller than the pressure decrease rate threshold value a0, the shutoff valve 3
Determines that the gas fuel has been supplied to the fuel cell 1 side without shutting off the gas fuel, and sets the shutoff valve failure flag.

At step 480, since the pressure reduction rate a2 is not smaller than the pressure reduction rate threshold value a0, it is judged that the shutoff valve 3 shuts off the gas fuel, and the shutoff valve failure flag is cleared.

At step 490, the routine proceeds to a failure processing routine (not shown). When the shutoff valve failure flag is set, the system is stopped and failure processing is performed, such as notifying the driver that there is a failure, and the process proceeds to the next step and ends.

By performing the above processing, even if the fuel cell 1 cannot consume the fuel at the target fuel consumption rate C1, the combustor 9
By using, it becomes possible to consume the fuel at the target fuel consumption rate C1, and it becomes possible to perform the failure diagnosis of the shutoff valve 3 in a shorter time.

In the present embodiment, in addition to the effects of the first embodiment, the fuel cell 1 as fuel consumption means is provided with the combustor 9 as auxiliary fuel consumption means in parallel,
Fuel supply ratio control unit 10 as fuel supply ratio control means
Controls the ratio of fuel supplied to the fuel cell 1 and the combustor 9 according to the target fuel consumption rate C1 and the fuel consumption rate of the fuel cell 1. Therefore, the fuel consumption rate of the fuel cell 1 is the target fuel consumption rate C1.
When not enough, the fuel can be consumed at the target fuel consumption rate C1 by supplying the fuel to the combustor 9.

Further, since the auxiliary fuel consuming means is constituted by the combustor 9, even when the fuel cell 1 cannot sufficiently consume the gas fuel, the fuel supply ratio controller 10 causes the combustor 9 to operate.
Consumes gas fuel, it is possible to consume fuel at the target fuel consumption rate C1.

(Third Embodiment) Hereinafter, an embodiment for realizing the gas fuel supply system according to the present invention will be described in claims 2-5.
Will be described based on the third embodiment.

11 to 13 show an example of a gas fuel supply apparatus according to the third embodiment of the present invention, which is a secondary battery capable of charging the electric power generated by the fuel cell with respect to the first embodiment. It has a battery added. FIG. 11 is a system configuration diagram, and FIGS. 12, 13 and 4 are control flowcharts for failure diagnosis.

In FIG. 11, the secondary battery 8 is the fuel cell 1
It is possible to charge the electric power generated by the electric power generation unit, and to discharge the electric power consumption unit 11. Secondary battery 8
The charging state of changes according to the power generation amount of the fuel cell 1 and the power consumption amount of the power consumption unit 11.

The fault detecting section 63 starts the fault diagnosis from the fault diagnosis signal. Before closing the shutoff valve 3, the failure detection unit 63 calculates a power adjustment amount so that the secondary battery 8 can be charged with the extra power generated by the fuel cell 1 by the failure diagnosis, and the fuel consumption control unit. Output to 73.

The fuel consumption control unit 73 receives the target fuel consumption rate C1 and the power adjustment amount from the failure detection unit 63, the fuel consumption rate from the fuel cell 1, and calculates the target power generation amount and the target power consumption amount. . When the power adjustment amount changes, the balance between the target power generation amount and the target power consumption amount also changes, and the state of charge of the secondary battery 8 can be changed.

Next, the detailed procedure of the failure diagnosis of the second embodiment will be described based on the flowcharts of FIGS. 12, 13 and 4. Steps 100 to 195 shown in FIG.
Indicates the condition setting for failure diagnosis, and step 221 shown in FIG.
˜241 shows the operation of the fuel consumption control section 73, and steps 300-380 shown in FIG. 4 show the operation of the failure diagnosis.

In the part relating to steps 100 to 150 of the condition setting of the failure diagnosis shown in FIG. 12, the failure diagnosis start signal is detected in step 100, the target fuel consumption rate C1 is set in step 110, and the predetermined time t0 is set. The pressure reduction rate threshold value a0 is calculated in step 130, the target power generation amount is set in step 140, and the target power consumption amount C1 is set in step 150. Is the same as.

At step 160, the charge state of the secondary battery 8 is read, and the routine proceeds to step 170.

At step 170, the power adjustment amount is set as follows, and the routine proceeds to step 180. The electric power generated is calculated from the amount of hydrogen n that the fuel cell 1 must consume to make a failure diagnosis. From the calculated electric power, the electric power used by the auxiliary device necessary for operating the fuel cell 1 is subtracted. A target state of charge that allows the secondary battery 8 to be charged with this power is calculated. The difference between the state of charge of the secondary battery 8 read in step 160 and the target state of charge is calculated, and the amount of power adjustment to the secondary battery 8 is calculated.

The first target power generation amount adjusted in step 180 and the first target power consumption amount adjusted in step 190 are adjusted so that the state of charge of the secondary battery 8 matches the target state of charge. For example, the first target power consumption amount is set to a minimum value necessary to avoid wasting power, and the first target power generation amount is a desired time for which the state of charge of the secondary battery 8 becomes the target state of charge. The first target power generation amount may be set so that the charging state becomes the target charging state at the set time.

In step 195, it is determined whether or not the charge state of the secondary battery 8 has reached a state where the power generated by the failure diagnosis can be charged. If so, the process proceeds to step 221 which is the operation of the fuel consumption control unit 73 in FIG.
If not, steps 160 to 190 are executed again.

In step 221, which is the operation of the fuel consumption control section 73 in FIG. 13, the fuel cell 1 is operated at the target fuel consumption rate C1.
Adjusts the second target power generation amount so that hydrogen consumes hydrogen, and proceeds to step 231.

At step 231, the target power consumption amount is adjusted so that the power consumption portion 11 consumes the power generated by the fuel cell 1, and the routine proceeds to step 241.

At step 241, it is judged whether the difference between the fuel consumption rate of the fuel cell 1 and the target fuel consumption rate C1 is within a predetermined range. If it is within the range, it is the operation of the failure diagnosis.
Via B in step 300, the process proceeds to step 300. If it is out of the range, the process proceeds to step 221, and steps 221 to 241 again.
To execute.

Then, the failure diagnosis processing of steps 300 to 380 in FIG. 4 (which has already been described in detail in the first embodiment and will be briefly described here) is performed, the shutoff valve 3 is closed, and the predetermined operation is performed. The gas fuel pressure P1 of the fuel supply line 4 after the lapse of time t0 is detected, and the pressure decrease rate a1 (= (P0-
P1) / t0) is calculated and compared with the pressure drop threshold value a0 to diagnose the failure of the shutoff valve 3, and the process ends.

As described above, since the electric power generated by the fuel cell 1 is stored in the secondary battery 8 in addition to being consumed by the electric power consuming portion 11, it is possible to perform the failure diagnosis of the shutoff valve 3 in a shorter time. Moreover, since the generated power is stored in the secondary battery 8, the gas fuel and the generated power are not wasted.

In addition to the effects of the first embodiment, this embodiment can achieve the effects described below. That is, since the extra energy obtained for the failure diagnosis of the shutoff valve 3 is stored in the secondary battery 8 as the energy storage means, the failure diagnosis can be performed in a shorter time without wasting the fuel.

Before the failure diagnosis of the shutoff valve 3, the storage amount of the secondary battery 8 serving as the energy storage means is adjusted, so that the secondary battery 8 is adjusted according to the energy obtained by the failure diagnosis.
It is possible to store the extra amount of energy obtained by the failure diagnosis in the secondary battery 8 by preserving the storage amount thereof and to perform the failure diagnosis without wasting energy.

In addition, in the first embodiment, as shown in FIG.
(Fault diagnosis condition setting), FIG. 3 (fuel consumption control unit operation), and FIG. 4 (fault diagnosis operation). In the second embodiment, FIG. 2 (fault diagnosis condition setting), FIG. (Operation of fuel consumption control unit), FIG. 9 (fault diagnosis operation), and in the third embodiment, FIG. 12 (fault diagnosis condition setting), FIG.
3 (operation of fuel consumption control unit), FIG. 4 (fault diagnosis operation)
There are three types of configurations. However, these combinations are not limited to the above combinations, and although not shown, for example, the combinations shown in FIGS. 12, 8 and 4 may be used. That is, if the combination is started in FIG. 2 or FIG. 12, proceeds to any one of FIG. 3, FIG. 8 and FIG. Can be performed in a shorter time.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a gas fuel supply device showing an embodiment of the present invention.

FIG. 2 is a control flowchart for setting conditions for failure diagnosis.

FIG. 3 is a control flowchart of a fuel consumption amount control unit for failure diagnosis, which is also the same as FIG.

FIG. 4 is a control flowchart showing an operation of failure diagnosis following FIG.

FIG. 5 is a graph showing a relationship between a target fuel consumption rate and consumption time.

FIG. 6 is a graph showing the relationship between the pressure detected by the pressure sensor for failure diagnosis by measuring the pressure drop amount after a predetermined time from the time when the shutoff valve is closed and the time.

FIG. 7 is a system configuration diagram of a gas fuel supply device showing a second embodiment of the present invention.

FIG. 8 is a control flowchart of a fuel consumption amount control unit for failure diagnosis following FIG.

FIG. 9 is a control flow chart showing an operation of failure diagnosis following FIG.

FIG. 10 is a graph showing a relationship between pressure detected by a pressure sensor for failure diagnosis by measuring elapsed time required for a predetermined pressure decrease from the time when the shutoff valve is closed and time, and time.

FIG. 11 is a system configuration diagram of a gas fuel supply device showing a third embodiment of the present invention.

FIG. 12 is a control flowchart for setting condition for failure diagnosis.

FIG. 13 is a control flowchart of a fuel consumption control section for failure diagnosis following FIG.

[Explanation of symbols]

1 Fuel Cell as Fuel Consumption Means 2 Fuel Tank as Fuel Supply Means 3 Shutoff Valve 4 Fuel Supply Line 5 Pressure Sensor 6 Controller 8 Secondary Battery 9 as Energy Storage and Electricity Storage Means Combustor as Auxiliary Fuel Consumption Means 10 Fuel Supply Ratio Control Section (Fuel Supply Ratio Control Means) 11 Electric Power Consumption Sections 61, 62 Failure Detection Section (Failure Detection Means) 71, 72, 73 Fuel Consumption Amount Control Section (Fuel Consumption Control Means)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toru Fuse             Nissan, Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan             Inside the automobile corporation F term (reference) 5H027 AA02 BA13 KK05 KK25 MM09

Claims (7)

[Claims] 1. A fuel supply means supplies fuel to a fuel consuming means, a fuel supply line having a shutoff valve and a pressure sensor, and the shutoff valve is closed based on a failure diagnosis signal, and at least from the pressure sensor. Failure detection means for calculating a pressure decrease rate based on pressure information and elapsed time, and determining that the shutoff valve is in a failure state when the pressure decrease rate is smaller than a predetermined pressure decrease rate threshold value. The gas fuel supply device having: a fuel consumption control means for increasing and controlling a target fuel consumption rate consumed by the fuel consumption means under a condition that the failure detection means operates based on the failure diagnosis signal. A gas fuel supply device characterized by: 2. The gas fuel supply device according to claim 1, further comprising, in addition to the fuel consuming means, an energy storage means for storing energy obtained by the fuel consumed at the time of executing the failure diagnosis of the shutoff valve. 3. The gas fuel supply device according to claim 2, wherein the energy storage means adjusts the energy storage amount before the failure diagnosis of the shutoff valve. 4. The fuel supply means is a hydrogen tank for storing hydrogen-rich gas fuel, the fuel consuming means is a fuel cell, and the energy storage means is an electric power storage means. The gas fuel supply device according to any one of claims 1 to 3. 5. The gas fuel supply device according to claim 4, wherein the failure detection unit adjusts the state of charge of the power storage unit according to the generated power calculated from the amount of hydrogen required for diagnosis. . 6. The fuel consumption means includes auxiliary fuel consumption means in parallel, and the fuel supply line controls a fuel supply ratio control means for controlling a ratio of supplying fuel to the fuel consumption means and the auxiliary fuel consumption means. The gas fuel supply device according to claim 1, further comprising: 7. The gas fuel supply apparatus according to claim 6, wherein the auxiliary fuel consuming means is a combustor.