JP2022053799A - Valve abnormality determination device and method - Google Patents

Abstract

To suppress erroneous determination of abnormality of a tank valve without increasing gas discharge force.SOLUTION: A pressure of a closed space is detected by a sensor provided with the closed space formed at a downstream side from a tank valve as a first valve, the pressure of the closed space is increased by a pressure of gas charged into the tank, the gas of the closed space is released into the external by temporarily opening a second valve from a first state of closing the first valve, thus the pressure of the closed space is lowered with respect to the pressure in the first state, and a second state in which the second valve is closed is made. Then, presence or absence of valve closing abnormality of the first valve is determined by a predetermined first determination method when a pressure reduction amount to the second state is less than a predetermined threshold value, and determined by a second determination method having accuracy higher than that of the first determination method when the pressure in the second state is the threshold value or more.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a technique for determining a valve closing abnormality of a valve provided in a tank filled with gas.

In fuel cell vehicles and the like, a tank valve such as a solenoid valve that is electrically opened and closed is provided at the outlet of the installed fuel gas tank. When fuel gas is not used, this tank valve is closed by an electric signal to stop the outgassing. In such a tank valve, it is required that the gas passing through the valve closed (hereinafter referred to as the gas passing through when the valve is closed) is equal to or less than the allowable value. If the gas passing through when the valve is closed is larger than the permissible value, it is usually indicated on the instrument panel or the like as an abnormality in the tank valve and notified.

The following Patent Document 1 discloses a method for detecting a gas passing through such a valve when the valve is closed. Specifically, various solenoid valves provided in the flow path from the tank filled with fuel gas to the fuel cell through the tank valve are controlled to create a closed space, and gas is released from this closed space. Let it lower the pressure inside it. After that, the closed space is set again, and the pressure fluctuation in the closed space in this state is measured to measure the amount of gas passing through the tank valve when the valve is closed.

International Publication WO2005 / 088756A1 Gazette

The technique described in Patent Document 1 is excellent in detecting the amount of gas passing through when the valve is closed with high accuracy over a wide range, but at the time of measurement, the gas in the closed space is released to reduce the internal pressure. Therefore, if the depressurized amount is increased to measure the amount of gas passing through when the valve is closed, the amount of gas released to the outside increases. On the other hand, if the amount of gas released is suppressed, the pressure in the closed space cannot be sufficiently reduced, for example, to a pressure that allows multiple measurements. This problem is related to a trade-off, and not only for fuel cell vehicles, but also when the amount of gas passing through the tank valve provided at the outlet of the gas tank exceeds the permissible value, the tank valve has a valve closing abnormality. It is common to those that are judged to exist.

The present disclosure can be realized as the following forms or application examples.

(1) The first aspect of the present disclosure is an aspect as a valve abnormality determination device. This valve abnormality determination device includes a tank filled with gas at a pressure higher than that of the outside air, a first valve provided at the outlet of the tank and opening and closing the gas flow path in response to an external instruction, and the first valve. A second valve that is provided in the flow path on the downstream side from the valve to form a closed space between the valve and the first valve by opening the valve, and releases the gas in the closed space to the outside by opening the valve. A sensor that detects the pressure in the closed space and a control unit that controls the opening and closing of the first and second valves, in which the closed space is increased in pressure by the pressure of the gas filled in the tank. By temporarily opening the second valve from the first state in which the first valve is closed, the gas in the closed space is released to the outside, and the closed space becomes the first valve. The closing detected by the sensor with the operation of the control unit in which the pressure is lower than the pressure of the state and the second valve is closed and the first valve and the second valve are operated. It is provided with an abnormality determination unit that evaluates the amount of gas passing through the first valve when the valve is closed from the change in the pressure in the space and determines the presence or absence of an abnormality in the valve closing of the first valve. Here, when the pre-decompression amount from the first state to the second state is less than a predetermined threshold value, the abnormality determination unit determines the pressure detected by the sensor after the second valve is closed. Of the methods for determining the valve closing abnormality of the first valve based on the change in the above, the presence or absence of the valve closing abnormality of the first valve is determined by the predetermined first determination method, and the depressurization to the second state is performed. When the amount is equal to or greater than the threshold value, the presence or absence of the valve closing abnormality is determined by the second determination method, which is more accurate than the first determination method.
In this way, when the amount of decompression from the first state to the second state is equal to or greater than the threshold value, the presence or absence of the valve closing abnormality is determined by the second determination method, which is more accurate than the first determination method. Therefore, it is possible to reduce the possibility of erroneous determination in the abnormality determination of the first valve. Moreover, it is possible to suppress an increase in the amount of gas released from the closed space.
(2) In such a valve abnormality determination device, the second determination method may be a method in which the number of determinations due to a change in pressure is larger than that of the first determination method. By doing so, since the second determination method has a large number of determinations, the possibility of erroneous determination can be reduced.
(3) In such a valve abnormality determination device, the second determination method performs a process of determining a valve closing abnormality of the first valve based on a change in pressure detected by the sensor after the valve closing of the second valve. After performing once, when the pressure in the closed space is within a predetermined pressure range with respect to the pressure in the first state, it may be determined that the first valve has a valve closing abnormality. .. By doing so, even if the pressure in the closed space has a large amount of gas passing through when the valve is closed and the pressure in the closed space approaches the first state by one process of determining an abnormality, the abnormality of the first valve is abnormal. You can avoid erroneous judgment.
(4) In such a valve abnormality determination device, the second determination method may be a method in which the time for detecting the change in pressure is longer than that of the first determination method. By doing so, since the second determination method can easily maintain the number of determinations, the possibility of erroneous determination can be reduced.
(5) In such a valve abnormality determination device, the tank may be a gas tank filled with fuel gas supplied to the fuel cell, and the second valve may be an injector for supplying the fuel gas to the fuel cell. good. By doing so, it is possible to easily determine the valve closing abnormality of the valve provided in the tank that supplies the fuel gas to the fuel cell by using the existing device.
(6) The second aspect of the present disclosure is an aspect as a valve abnormality determination method. In this valve abnormality determination method, the pressure in the closed space is detected by a sensor provided in the flow path on the downstream side of the tank valve and provided in the closed space formed on the downstream side of the tank valve, and the pressure in the closed space is detected. The pressure in the closed space is increased by the pressure of the gas filled in the tank, and the tank valve is closed in the first state. From the first state, the discharge valve provided in the flow path is temporarily released. By opening the valve, the gas in the closed space is discharged to the outside, the pressure in the closed space is reduced from the pressure in the first state, and the release valve is closed in the second state. When the amount of decompression from the first state to the second state is less than a predetermined threshold value, the valve closing abnormality of the tank valve is caused by the change in pressure detected by the sensor after the valve closing of the release valve. Among the determination methods, the presence or absence of a valve closing abnormality of the tank valve is determined by a predetermined first determination method, and when the depressurization amount to the second state is equal to or greater than the threshold value, the first determination method is used. The presence or absence of the valve closing abnormality is determined by the second determination method, which is more accurate than the determination method of.
According to this abnormality determination method, when the decompression amount from the first state to the second state is equal to or greater than the threshold value, the valve closing abnormality is performed by the second determination method having higher accuracy than the first determination method. Since it is determined whether or not there is an abnormality, the possibility of erroneous determination in the abnormality determination of the tank valve can be reduced. Moreover, it is possible to suppress an increase in the amount of gas released from the closed space.

The schematic block diagram of the valve abnormality determination apparatus of an embodiment. The flowchart which shows the tank valve abnormality determination processing in 1st Embodiment. An explanatory diagram showing a state of determination when the pressure in a closed space can be sufficiently reduced in the first embodiment. An explanatory diagram showing a state of determination when the pressure drop in a closed space is insufficient in the first embodiment. The flowchart which shows the tank valve abnormality determination processing in 2nd Embodiment. The flowchart which shows the tank valve abnormality determination processing in 3rd Embodiment. Explanatory drawing which shows the state of determination in 3rd Embodiment.

First Embodiment:
(1) Hardware configuration:
FIG. 1 shows a schematic configuration of a valve abnormality determination device 20 in a fuel cell system. As shown in the figure, the tank valve 53 corresponding to the first valve is provided in the gas tank (hereinafter, simply referred to as a tank) 51 used in the fuel cell system. First, the schematic configuration of the fuel cell system will be briefly described. The fuel cell system includes a fuel cell 30, an air supply / exhaust system 40 that supplies and exhausts an atmosphere containing oxygen, a hydrogen supply / exhaust system 50 that supplies and discharges hydrogen, and a cooling water circulation system (not shown). There is.

The fuel cell 30 is a power generation device for electrochemically reacting a fuel gas and an oxidation gas to extract electric power, and has a stack configuration in which a plurality of single cells are stacked. The fuel cell 30 of the present embodiment is a polymer electrolyte fuel cell, but other types of fuel cells may be used. In each single cell constituting the fuel cell 30, a flow path (hereinafter, also referred to as an anode side flow path) through which hydrogen, which is a fuel gas flows, is formed on the anode side via an electrolyte membrane, and an oxidation gas is formed on the cathode side. A flow path through which air flows (hereinafter, also referred to as a cathode side flow path) is formed.

In the air supply / exhaust system 40, the air supply pipe 41 that guides the air supplied by the compressor (not shown) to the cathode side flow path in the fuel cell 30 and the air that has consumed a part of oxygen in the fuel cell 30 are exhausted. The air exhaust pipe 43 is provided. The air exhaust pipe 43 is connected to the diluter 67.

The hydrogen supply / exhaust system 50 is for supplying the hydrogen stored in the tank 51 to the anode side flow path of the fuel cell 30, and is connected to the pipeline 52 from the tank 51 to the anode side flow path inlet of the fuel cell 30. , A tank valve 53, a pressure regulating valve 55, and an injector 57 corresponding to a second valve (discharge valve) are provided in order from the tank 51 toward the downstream side. Further, a circulation pipe 64 for connecting the anode exhaust gas to the anode side flow path inlet is provided at the anode side flow path outlet of the fuel cell 30 via the gas-liquid separator 65, and the hydrogen circulation pump 63 is provided therein. It is provided. The anode exhaust gas after the water is separated by the gas-liquid separator 65 is diluted with air by the diluter 67 and discharged to the outside of the system.

The pipeline 52 of the hydrogen supply / exhaust system 50 is provided with pressure gauges for high pressure, medium pressure, and low pressure. A first pressure gauge 71 is between the tank valve 53 and the pressure regulating valve 55, a second pressure gauge 72 is located between the pressure regulating valve 55 and the injector 57, and a third pressure gauge 73 is downstream of the injector 57. However, each is provided. Further, the base of the tank 51 is provided with a temperature sensor 75 that detects the temperature T of the gas taken out from the tank 51.

The valve abnormality determination device 20 includes a fuel cell control ECU 80. The fuel cell control ECU 80 has a well-known CPU, ROM, RAM, and the like built-in, and by executing a program stored in the ROM, the operation of the fuel cell 30 is controlled and the abnormality of the tank valve 53 is determined. .. In the figure, only the portion of the inside of the fuel cell control ECU 80 that is involved in the abnormality determination of the tank valve 53, that is, the abnormality determination unit 81, the control unit 82, and the output unit 83 is shown. Further, the fuel cell control ECU 80 is connected to various sensors and actuators already described, and inputs a detection signal and outputs a control signal for determining an abnormality of the tank valve 53. The signals input to the fuel cell control ECU 80 regarding the abnormality determination are the pressure detection signal P1 from the first pressure gauge 71, the pressure detection signal P2 from the second pressure gauge 72, and the pressure detection signal P3 from the third pressure gauge 73. , The temperature detection signal T from the temperature sensor 75, and the like. Further, the control signal output by the fuel cell control ECU 80 regarding the abnormality determination is a control signal S1 for instructing opening / closing of the tank valve 53 which is the first valve, a control signal S2 for driving the injector 57 which is the second valve, and the like. be. When the fuel cell 30 is operated, the fuel cell control ECU 80 outputs a signal to other parts such as outputting a control signal to the hydrogen circulation pump 63, or inputs a signal. Since these signals are not directly related to the abnormality determination of the tank valve 53, the illustration and description are omitted.

(2) Method for determining tank valve closing abnormality:
The valve abnormality determination device 20 determines the valve closing abnormality of the tank valve 53, which is performed as follows. The tank valve 53 is opened when the fuel cell 30 is in operation. In this case, if the injector 57 is closed, the inside of the pipeline 52 from the tank valve 53 to the injector 57 becomes equal to the pressure in the tank 51. This state is called the first state. When the tank valve 53 is closed from this state, hydrogen does not flow out from the pipeline 52 from the tank valve 53 to the injector 57, so that a closed space 60 is formed during this period. The pressure in the closed space 60 can be detected by the first pressure gauge 71 or the second pressure gauge 72. In the following description, it is assumed that the first pressure gauge 71 is used.

Next, when the injector 57 is temporarily opened, that is, for a predetermined time, the pressure in the closed space 60 is higher than the pressure in the anode side flow path of the fuel cell 30, so hydrogen in the closed space 60 is ejected from the injector 57. However, the pressure in the closed space 60 is reduced by that amount. This is called the decompression amount ΔP. When the injector 57 closes after a designated time, the pressure drop in the closed space 60 stops and the pressure in the closed space 60 is maintained. This state is called the second state. At this time, if there is a gas passing through the closed tank valve 53 from the tank 51 side at the time of valve closing, the pressure in the closed space 60 rises. If the change in pressure at the time of this rise is detected, the flow rate of the gas passing through the tank valve 53 when the valve is closed is in the normal state of being less than the permissible value, or the flow rate of the gas passing through when the valve is closed exceeds the permissible value. It can be determined whether the tank valve 53 has a valve closing abnormality. This is because the gas constant R is used between the volume V of the closed space 60, the pressure P of the closed space 60, the temperature T of the gas in the closed space 60, and the mass (number of moles) n of the gas in the closed space 60. , The following equation of state,
P = nRT / V
Therefore, when gas flows in from the tank 51 side through the closed tank valve 53, the mass of the gas in the closed space 60 increases, and as a result, the pressure P in the closed space 60 also rises. be.

Since the increase in pressure in the closed space 60 is caused by the flow rate of the gas passing through the closed tank valve 53 when the valve is closed, the change in pressure is proportional to the flow rate of the gas passing through the tank valve 53 when the valve is closed. Since it takes a certain amount of time to detect this accurately, the tank is based on the difference between the pressure in the closed space 60 immediately after the injector 57 is closed and the pressure in the closed space 60 when the detection time Tpp has elapsed. The flow rate Q of the passing gas when the valve 53 is closed can be obtained. The flow rate of the gas passing through when the valve is closed is evaluated, and if the flow rate exceeds the permissible value, it is determined that the tank valve 53 has a valve closing abnormality.

The tank valve abnormality determination process performed by the valve abnormality determination device 20 based on the determination principle described above will be described with reference to the flowchart of FIG. 2 and the explanatory diagram of FIG. FIG. 3 shows the temporal change of the pressure in the closed space 60. The process shown in FIG. 2 is executed when the supply of the fuel gas or the like to the fuel cell 30 is stopped and the operation of the fuel cell 30 is terminated. The fuel cell control ECU 80 stops the operation of the fuel cell 30 and starts the abnormality determination process shown in FIG. Since the operation of the fuel cell 30 is terminated, the tank valve 53 has already been closed before the start of this process. When starting this process, the variable N indicating the number of times the abnormality is determined is initialized and set to the value 1.

When the tank valve abnormality determination process is started, the depressurization process is first performed (step S100). The depressurization treatment is performed by opening the injector 57 for a predetermined time. When the injector 57 is opened, the high-pressure gas in the closed space 60 is discharged toward the fuel cell 30, and the pressure in the closed space 60 decreases. This situation is shown in FIG. As shown in the figure, when the injector 57 opens the valve for a time from time t1 to t2, the pressure in the closed space 60 drops from the pressure PP1 in the first state to the pressure PP2 in the second state during that time. These pressures can be detected by reading the output of the first pressure gauge 71 or the second pressure gauge 72 at a predetermined sampling time.

Therefore, next, the decompression amount ΔP is calculated (step S110). The decompression amount ΔP is
ΔP = PP1-PP2
Can be obtained as. When the decompression amount ΔP is obtained, it is determined whether or not the decompression amount ΔP is smaller than the predetermined decompression threshold value TDp (step S120). This decompression threshold value TDp is a threshold value for determining whether or not the decompression required for the subsequent two abnormality determinations has been performed. If the decompression amount ΔP is smaller than the decompression threshold TDp (step S120: “YES”), the value 1 is substituted into the set value M indicating the number of times of abnormality determination (step S130), and the decompression amount ΔP is equal to or more than the decompression threshold TDp. If (step S130: "NO"), the value 2 is assigned to the set value M (step S135).

After that, it waits until the preset time Tpp elapses, and detects the passing gas amount Q (N) at the time of valve closing. Here, the amount of gas passing through when the valve is closed Q (N) means the flow rate per hour. The amount of gas Q (N) passing through when the valve is closed can be detected by multiplying the pressure difference P (N) generated during the time Tpp by the coefficient k obtained from the volume V of the closed space 60 and the temperature T. Expressed in a formula,
Q (N) = k ・ P (N) / Tpp
Is. That is, at the time of the first abnormality determination, the pressure difference P (1) due to the increase in pressure generated during the time Tpp is used.
Q (1) = k · P (1) / Tpp = k · (PP3-PP2) / Tpp
As a result, the amount of gas Q (1) passing through when the valve is closed is obtained.

Next, it is determined whether or not the flow rate Q (N) passed through for the first abnormality determination obtained in this way exceeds the predetermined allowable value TQ (step S150). If the flow rate Q (N) passing through when the valve is closed exceeds the permissible value TQ (step S150: “YES”), it is considered that a valve closing abnormality may have occurred in the tank valve 53, and the flag F (N) is set. If the value 1 is set (step S160) and the flow rate Q (N) passing through when the valve is closed does not exceed the allowable value TQ (step S150: "NO"), it is assumed that the tank valve 53 has no valve closing abnormality. The value 0 is set in the flag F (N) (step S165). Subsequently, the variable N indicating the number of times of abnormality determination is incremented by the value 1 (step S170), and it is determined whether the variable N is larger than the set value M set in step S130 or S135 (step S180). If the set value M is set to the value 1, the variable N indicating the number of processing of the abnormality determination exceeds the set value M by incrementing in step S170, so that the determination in step S180 becomes “YES” and described above. When the processing of steps S140 to S165 is performed once, the process proceeds to the abnormality determination of step S200. On the other hand, if the set value M is set to the value 2, the determination in step S170 becomes "NO", and the process returns to step S140 to perform the second abnormality determination process.

In the example shown in FIG. 3, the pressure PP in the closed space 60 can be sufficiently reduced by the decompression treatment (step S100) (ΔP ≧ TDp), and the abnormality determination can be performed correctly even if the abnormality determination time Tpp is set twice. Shows. In FIG. 2, the broken line B1 indicates the case where the flow rate Q of the gas passing through when the tank valve 53 is closed is an allowable value, and the solid line J1 indicates the case where the flow rate Q of the passing gas when closing the valve is larger than the allowable value. show. As can be seen from the figure, the flow rate Q (1) is the flow rate detected in the first abnormality determination, and is obtained from the differential pressure P (1) between the pressure PP3 and the pressure PP2 detected by the first pressure gauge 71. .. Similarly, the flow rate Q (2) is the flow rate detected in the second abnormality determination, and is obtained from the differential pressure P (2) between the pressure PP4 and the pressure PP3 detected by the first pressure gauge 71.

When the set value M is a value 2, the determination in step S180 becomes “YES” when the second abnormality determination is performed, and the process proceeds to the abnormality determination (step S200). In the abnormality determination (step S200), the abnormality determination is performed according to the table TB1. That is, if the results of the first abnormality judgment and the second abnormality judgment are combined and the judgment can be made twice, if the value 0 is set in the flag F (N) even once, the value 0 is set. That is, if it is determined that the tank valve 53 has no valve closing abnormality even once, it is determined to be "normal". When both the flags F (1) and F (2) are set to the value 1 in the two abnormality determinations, it is determined to be "abnormal". On the other hand, when the decompression amount ΔP is smaller than the decompression threshold value TDp and the abnormality determination can be performed only once, it is determined as “normal” or “abnormal” according to the result of the one abnormality determination. In the table TB1, the case where the abnormality judgment can be made only once is shown as "N / A" for F (2).

On the other hand, when it is determined in step S120 that the decompression amount ΔP is less than the decompression threshold TDp, the set value M is set to the value 1, so that the abnormality determination (steps S140 and S150) is performed only once. .. This situation is shown in FIG. As in FIG. 3, the broken line B2 indicates the case where the flow rate Q of the gas passing through when the tank valve 53 is closed is an allowable value, and the solid line J2 indicates the case where the flow rate Q of the passing gas when closing the valve is larger than the allowable value. show. In this example, since the decompression amount ΔP is less than the decompression threshold value TDp, the pressure in the closed space 60 may return to the pressure before decompression before the two detection times Tpp × 2 elapse. If there is such a possibility, since the second judgment is not performed, it is erroneously determined that the gas amount Q (N) passing through when the tank valve 53 is closed is equal to or less than the allowable value, and the flag F (N) is set to a value. Never set to 0.

In the present embodiment described above, in the depressurization process (step S100) for detecting the valve closing abnormality of the tank valve 53, the number of abnormality determinations is changed depending on whether or not the decompression amount ΔP is smaller than the decompression threshold value. Therefore, both ensuring the accuracy of abnormality judgment and suppressing the amount of gas released are achieved. That is, when the decompression amount ΔP is less than the decompression threshold TDp, the abnormality determination is performed only once as the first determination method, and when the decompression amount ΔP is the decompression threshold TDp abnormality, the second determination method is used. The accuracy of the abnormality judgment in the latter is improved by performing the abnormality judgment twice. In this way, by making the accuracy of the abnormality determination different depending on the decompression amount ΔP, it is not necessary to reduce the pressure in anticipation of a large margin that allows the abnormality determination to be performed twice. Since the depressurization is to release the fuel gas secured in the closed space 60, here hydrogen, to the outside, such a release amount can be suppressed. In particular, in a fuel cell system provided with a pressure regulating valve 55 and having a high pressure portion from the tank valve 53 to the pressure regulating valve 55 and a medium pressure portion from the pressure regulating valve 55 to the injector 57, the volume of the closed space 60 becomes large. Cheap. In such a case, the effect of suppressing the amount of released gas, which tends to increase in an attempt to secure a sufficient decompression amount ΔP, is great.

In the above embodiment, if the decompression amount ΔP is larger than the decompression threshold value TDp, the abnormality determination is performed twice, and if the gas amount Q (N) passing through when the valve is closed is equal to or less than the allowable value even once, the tank valve 53 is set. Although it is determined to be "normal", if it is determined that the value is equal to or less than the allowable value in the first determination, the second determination may not be performed. Alternatively, it may be determined as "abnormal" if it is not equal to or less than the allowable value both times. Further, in the above embodiment, the maximum number of judgments is set to 2, but it may be set to 3 or more.

Second embodiment:
Next, the second embodiment will be described. In the second embodiment, the same hardware configuration as in the first embodiment is used, and the tank valve abnormality determination process is different. FIG. 5 shows a flowchart of the abnormality determination process in the second embodiment. The same process as in the first embodiment is assigned the same step number, and the description is omitted or simplified.

In the second embodiment, regardless of the magnitude of the decompression amount ΔP and the decompression threshold value TDp, the number of times of abnormality determination is set to 2, and the detection time Tpp is changed. That is, the reduced pressure amount ΔP generated by the reduced pressure treatment (step S100) is detected (step S110), and the magnitude relationship between the reduced pressure amount ΔP and the reduced pressure threshold value TDp is determined (step S120). If the decompression amount ΔP is less than the decompression threshold value TDp, the detection time Tpp is shortened from the reference time Td by the time t0 (step S130A). On the other hand, if the decompression amount ΔP is equal to or greater than the decompression threshold value TDp, the detection time Tpp is set to the reference time Td (step S135A).

Subsequent processing (steps S140 to S170) is the same as in the first embodiment. After that, it is determined whether the variable N indicating the number of times of abnormality determination is larger than the value 2 (step S180A), and the above processing is repeated until the abnormality determination is performed twice. When the abnormality determination is performed twice (step S180A: "YES"), the abnormality determination is performed (step S200A). In the second embodiment, since the abnormality determination is performed twice, the valve closing abnormality of the tank valve 53 is determined by the combination of the two abnormality determinations. An example of this determination is shown as table TB2. Similar to the first embodiment, the determination shown in the table TB2 is a tank valve if the gas amount Q (N) passing through when the tank valve 53 is closed is equal to or less than the allowable value even once out of the two abnormality determinations. Although 53 is determined to be "normal", it may be determined to be "abnormal" if it is not equal to or less than the allowable value both times.

In the second embodiment, when the decompression amount by the depressurization treatment is less than the decompression threshold TDp, the detection time Tpp is set shorter than the reference time Td as the first determination method. Since the detection time is shortened in this way, even when the decompression amount ΔP is smaller than the decompression threshold value TDp, it is possible to perform the abnormality determination twice. Moreover, when the decompression amount by the decompression treatment is ΔP equal to or more than the decompression threshold value TDp, the detection time Tpp is set as the reference time Td as the second determination method. The amount is higher than when ΔP is less than the decompression threshold TDp. When the detection time Tpp is changed, the permissible value TQ in the determination (step S150) of determining whether the gas passing gas amount Q (N) at the time of valve closing exceeds the permissible value TQ is reduced in proportion to the detection time Tpp. Further, in the above embodiment, when the decompression amount ΔP is less than the decompression threshold value TDp, the time t0 for shortening the detection time Tpp to the reference time Td is set to a fixed value, but it is set to, for example, an inversely proportional value according to the decompression amount ΔP. You may do so. In this way, the smaller the decompression amount ΔP, the shorter the detection time, and the higher the possibility that the two abnormality determinations can be completed before the pressure in the closed space 60 returns to the pressure before the decompression.

Third embodiment:
Next, the third embodiment will be described. The third embodiment also uses the hardware configuration as in the first and second embodiments, and the tank valve abnormality determination process is different. FIG. 6 shows an example of the abnormality determination process in the third embodiment. Further, in this case, the state of the pressure change in the closed space 60 is shown in FIG. In FIG. 6, the same processing as in the first and second embodiments is assigned the same step number, and the description is omitted or simplified.

In the third embodiment, the reduced pressure amount ΔP generated by the reduced pressure treatment (step S100) is detected (step S110), and the magnitude relationship between the reduced pressure amount ΔP and the reduced pressure threshold value TDp is determined (step S120). Then, depending on the magnitude of the decompression amount ΔP and the decompression threshold value TDp, the number of abnormality determinations is set to 2 or 1, and in the case of 2 times, the original pressure determination process (step S218) described later is performed. In FIG. 6, the first abnormality determination is shown as step S210, and the second abnormality determination is shown as step S220. Also in the third embodiment, the number of times of abnormality judgment is changed, and the number of times of abnormality judgment is twice as the second judgment method, as compared with the case where the number of times of abnormality judgment is once as the first judgment method. The accuracy of the judgment is higher in the case of.

When the decompression amount ΔP is less than the decompression threshold TDp, a value 1 is set in the flag FFN indicating the number of determinations (step S190), and when the decompression amount ΔP is equal to or more than the decompression threshold TDp, the flag FFN indicating the number of determinations is set. The value 2 is set (step S195). Then, the first abnormality determination process (step S210) is started.

In the first abnormality determination, the pressure PP3 in the closed space 60 after the lapse of a predetermined time Tpp is detected by the first pressure gauge 71 (step S212). From the detected pressure PP3, the pressure difference P (1) during the detection time Tpp can be obtained, and from this, the gas amount Q (1) passing through when the tank valve 53 is closed can be obtained. It is determined whether or not Q (1) is equal to or less than the allowable value TQ (step S214). If the amount of gas passing through when the valve is closed Q (1) is equal to or less than the allowable value TQ (step S214: "YES"), it is determined that the tank valve 53 is "normal" (step S270). This situation is shown in FIG. As shown in the figure, when the pressure difference P (1) obtained from the pressure PP3 in the closed space 60 at the time when the first detection time Tpp has elapsed is the allowable value for the amount of gas passing through when the valve is closed (broken line B3). If it is smaller than the pressure change, the tank valve 53 is determined to be "normal" at this point, exits to "END", and the processing routine ends.

On the other hand, in the first abnormality determination (step S210), the pressure difference P (1) obtained from the pressure PP3 in the closed space 60 at the time when the first detection time Tpp has elapsed is the allowable value of the amount of gas passing through when the valve is closed. In the case of (dashed line B3) or more, as shown by the solid line J3, it is determined that the gas amount Q (1) passing through when the tank valve 53 is closed is larger than the allowable value TQ (step S214: ". NO "), at this point, the tank valve 53 cannot be determined to be" normal ". Therefore, in this case, the process proceeds to step S216, and the value of the flag FFN set in step S190 or S195 is determined.

If the flag FFN has a value of 1 (step S216), it is determined that the decompression amount ΔP is less than the decompression threshold TDp and there is no pressure difference sufficient to make an abnormality determination again. Therefore, the result of step S214 (step S214). From Q (1)> TQ), it is determined that the tank valve 53 has a valve closing abnormality (step S280).

On the other hand, if the flag FFN has a value of 2 (step S216), it is determined that the decompression amount ΔP is equal to or greater than the decompression threshold TDp and there is a pressure difference sufficient to make another abnormality determination. The abnormality determination (step S220) is performed, but before that, the original pressure determination process (step S218) is performed. The process of determining the original pressure is to determine whether or not the pressure PP3 of the closed space 60 at the time when the first detection time Tpp has elapsed is larger than the predetermined threshold pressure TFP.

As illustrated in FIG. 7, if the amount of gas passing through when the tank valve 53 is closed is large, even if the decompression amount ΔP is larger than the decompression threshold value TDp, as shown by the broken line D1, the closed space 60 is after the detection time Tpp has elapsed. It is possible that the pressure of the pressure drops significantly and becomes higher than the threshold pressure TFP. In this case, when the second abnormality determination is performed, the pressure after the lapse of the second detection time Tpp returns to the pressure before the depressurization treatment (step S100), and the pressure difference P (2) becomes a small value. It may end up.

Therefore, if it is determined in step S218 that the pressure PP3 in the closed space 60 at the time when the first detection time Tpp has elapsed is larger than the predetermined threshold pressure TFP, the second abnormality determination is not performed. , It is determined in step S80 that the tank valve 53 has a valve closing abnormality. On the other hand, if it is determined in step S218 that the pressure PP3 in the closed space 60 at the time when the first detection time Tpp has elapsed is equal to or less than the predetermined threshold pressure TFP, the abnormality determination process can be performed once more. It is determined that the decompressed amount of No. 1 remains, and the second abnormality determination (step S220) is performed.

In the second abnormality determination, the pressure PP4 in the closed space 60 after the detection time Tpp has elapsed is detected as in the first abnormality determination (step S222). From the detected pressure PP4, the pressure difference P (2) during the detection time Tpp can be obtained, and from this, the gas amount Q (2) passing through the tank valve 53 when the valve is closed can be obtained. It is determined whether or not Q (2) is equal to or less than the allowable value TQ (step S224). If the amount of gas passing through when the valve is closed Q (2) is equal to or less than the allowable value TQ (step S224: "YES"), it is determined that the tank valve 53 is "normal" (step S270).

On the other hand, in the second abnormality determination (step S220), the pressure difference P (2) obtained from the pressure PP4 in the closed space 60 at the time when the second detection time Tpp has elapsed is the allowable value for the amount of gas passing through when the valve is closed. If it is equal to or greater than the pressure change in the case of (dashed line B3), it is determined that the gas amount Q (2) passing through when the tank valve 53 is closed is larger than the allowable value TQ (step S224: “NO”), and the tank at this point. The valve 53 cannot be determined to be "normal". Therefore, in this case, since it was not possible to determine that both the first abnormality determination and the second abnormality determination were "normal", it was determined that the tank valve 53 had a valve closing abnormality (step). S280). After the processing of these normal determination (step S270) or abnormality determination (step S280), the process exits to "END" and the present processing routine is terminated.

In the third embodiment described above, the number of abnormality determinations is set to once or twice depending on the magnitude of the decompression amount ΔP, and the same action and effect as those of the first embodiment are obtained, and the abnormality determination is performed twice. When the amount of gas passing through the tank valve 53 when the valve is closed is larger than expected and the pressure change in the closed space 60 is large and the pressure returns to or approaches the pressure before the decompression process. Since the second abnormality judgment is not performed (step S218: “YES”), no erroneous judgment is made in the second abnormality judgment. For this reason, even if the tank valve 53 is determined to be "normal" if the amount of gas Q (N) passing through when the valve is closed is equal to or less than the allowable value TQ even once when the abnormality is determined twice, an erroneous determination is made. The possibility of doing so can be suppressed.

In the third embodiment, the detection time Tpp is fixed, but as shown in the second embodiment, it may be variable depending on the decompression amount ΔP. In this case, two abnormality judgments will be attempted, but if the pressure in the closed space 60 matches or returns to the pressure before decompression after the first abnormality judgment, the second abnormality judgment will be made. The tank valve may be determined to be abnormal in closing without making a determination.

Other aspects:
In the first to third embodiments described above, the amount of decompression from the first state to the second state is compared with a predetermined threshold value. For example, there is a pressure regulating valve on the tank side of the tank valve 53 and the pressure is closed. When the pressure in the space 60 is maintained at a predetermined value, the same determination can be made by directly comparing the pressure in the second state with the threshold value. Alternatively, if the threshold value is set based on the pressure in the first state, the same judgment can be made by comparing the pressure in the second state with the threshold value.

In the above embodiment, the judgment of the valve closing abnormality of the tank valve 53 is performed by obtaining the passing gas amount Q (N) at the time of valve closing, but the evaluation of the gas amount does not calculate the passing gas amount (flow rate). It may be performed by the pressure change P (1) or P (2). This is because if the detection time Tpp is known, the gas flow rate can be evaluated by the pressure change.

The tank valve 53, which is the first valve, and the injector 57, which is the second valve, both use electric valves that are electrically driven, but they may be valves of a type that are driven by hydraulic pressure, pneumatic pressure, or the like. In these bubbles, by instructing the opening and closing of the hydraulic valve and the pneumatic valve, the flow path is opened and closed by the valve as a result.

In the above embodiment, when the determination of "abnormality" is made, the output unit 83 notifies the user of the fuel cell system of the determination result by turning on the lamp of the instrument panel or the like. Of course, the result may be notified to the diagnosis computer and the determination result may be stored, including the case of "normal". Even when the value Q (N) of the gas passing through the tank valve 53 when the valve is closed is not 0, the gas (hydrogen) in the closed space 60 leaks to the fuel cell 30 side because the injector 57 is closed. It never comes out.

In the above embodiment, the closed space 60 is a part of the pipeline 52 and is a conduit from the tank valve 53 to the injector 57, but a hydrogen gas circulation path between the tank valve 53 and the injector 57. If a circulation path opening / closing valve is provided in the circulation path and the pipeline can be shut off, the closed space 60 can be formed including the circulation path opening / closing valve. This is not limited to the circulation path of hydrogen gas, and the same applies to the case where another flow path or the like is provided. Any configuration may be used as long as a shutoff valve is provided to create a closed space 60.

Although some embodiments of the present disclosure have been described above, the valve abnormality determination device 20 of the present disclosure can be implemented even if it is not a fuel cell system. Further, when used in a fuel cell system, it is not limited to an in-vehicle system, and can be used, for example, for determining a valve closing abnormality of a valve provided in a tank of an installed fuel cell system. In such a case, the target fuel cell is not limited to the solid polymer type, but may be a phosphoric acid type fuel cell (PAFC), a molten carbonate type fuel cell (MCFC), a solid oxide type fuel cell (SOFC), or the like. Can also be applied. The first electric valve is not limited to the solenoid valve, and may be a type that drives the valve body by using a motor. Further, the one using a rotary solenoid or the one using a piezo element may be used. In addition, both valve opening and valve closing are not limited to electric ones. For example, valve closing is realized by a spring or magnetic force, and an electric signal is required at the time of valve opening, and vice versa. ..

The present disclosure is not limited to the valve of a hydrogen tank for a fuel cell, as long as it is a valve provided at the outlet of a tank filled with gas at a pressure higher than that of the outside air and opens and closes the gas flow path, and abnormality determination can be performed. can. For example, it can be applied to the determination of a valve closing abnormality of a valve provided in a tank such as propane gas or nitrogen gas. Of course, as described in each of the above-described embodiments, it can also be implemented as a valve abnormality determination method.

In each of the above embodiments, a part of the configuration realized by the hardware may be replaced with software. At least some of the configurations realized by software can also be realized by discrete circuit configurations. Further, when a part or all of the functions of the present disclosure are realized by software, the software (computer program) can be provided in a form stored in a computer-readable recording medium. The "computer-readable recording medium" is not limited to portable recording media such as flexible disks and CD-ROMs, but is fixed to internal storage devices in computers such as various RAMs and ROMs, and computers such as hard disks. It also includes external storage devices that have been installed. That is, the term "computer-readable recording medium" has a broad meaning including any recording medium on which data packets can be fixed rather than temporarily.

The present disclosure is not limited to the above-described embodiment, and can be realized by various configurations within a range not deviating from the gist thereof. For example, the technical features in the embodiments corresponding to the technical features in each embodiment described in the column of the outline of the invention are for solving a part or all of the above-mentioned problems, or one of the above-mentioned effects. It is possible to replace or combine as appropriate to achieve the part or all. Further, if the technical feature is not described as essential in the present specification, it can be appropriately deleted.

20 ... Valve abnormality determination device, 30 ... Fuel cell, 40 ... Air supply / exhaust system, 41 ... Air supply pipe, 43 ... Air exhaust pipe, 50 ... Hydrogen supply / exhaust system, 51 ... Tank, 52 ... Pipe line, 53 ... Tank Valve, 55 ... Pressure regulating valve, 57 ... Injector, 60 ... Closed space, 63 ... Hydrogen circulation pump, 64 ... Circulation pipeline, 65 ... Gas-liquid separator, 67 ... Diluter, 71 ... First pressure gauge, 72 ... 2nd pressure gauge, 73 ... 3rd pressure gauge, 75 ... temperature sensor, 80 ... fuel cell control ECU, 81 ... abnormality determination unit, 82 ... control unit, 83 ... output unit, TB1, TB2 ... table

Claims (6)

A tank filled with gas at a pressure higher than the outside air,
A first valve provided at the outlet of the tank that opens and closes the gas flow path in response to an external instruction.
It is provided in the flow path on the downstream side from the first valve, and by opening the valve, a closed space is formed between the first valve and the valve, and by opening the valve, the gas in the closed space is discharged to the outside. With the second valve
A sensor that detects the pressure in the closed space and
A control unit that controls the opening and closing of the first and second valves, in which the closed space is increased in pressure by the pressure of the gas filled in the tank, and the first valve is closed. By temporarily opening the second valve from the first state, the gas in the closed space is released to the outside, and the closed space is depressurized from the pressure in the first state, and the said. The control unit that puts the second valve in the second state when the valve is closed,
The amount of gas passing through the first valve when the first valve is closed is evaluated from the change in the pressure in the closed space detected by the sensor with the operation of the first valve and the second valve, and the first valve is used. Abnormality determination unit that determines the presence or absence of valve closing abnormality,
Equipped with
The abnormality determination unit is
When the amount of decompression from the first state to the second state is less than a predetermined threshold value, the valve of the first valve is closed due to the change in pressure detected by the sensor after the valve of the second valve is closed. Among the methods for determining an abnormality, the presence or absence of a valve closing abnormality of the first valve is determined by a predetermined first determination method.
When the decompression amount to the second state is equal to or greater than the threshold value, the presence or absence of the valve closing abnormality is determined by the second determination method, which is more accurate than the first determination method.
Valve abnormality determination device. The valve abnormality determination device according to claim 1, wherein the second determination method is a method in which the number of determinations due to a change in pressure is larger than that of the first determination method. In the second determination method, after the process of determining the valve closing abnormality of the first valve by the change in pressure detected by the sensor after the valve closing of the second valve is performed once, the closed space. The valve abnormality determination device according to claim 2, wherein when the pressure of the first valve is within a predetermined pressure range with respect to the pressure of the first state, it is determined that the first valve has a valve closing abnormality. The valve abnormality determination device according to claim 1, wherein the second determination method is a method in which a time for detecting a change in pressure is longer than that of the first determination method. The tank is a gas tank filled with fuel gas supplied to the fuel cell.
The valve abnormality determination device according to any one of claims 1 to 4, wherein the second valve is an injector that supplies the fuel gas to the fuel cell. It is a method to determine the abnormality of the tank valve that opens and closes the gas flow path, which is provided at the outlet of the tank where the gas is filled with a pressure higher than the outside air.
The pressure in the closed space is detected by a sensor provided in the flow path on the downstream side of the tank valve and provided in the closed space formed on the downstream side of the tank valve.
The pressure in the closed space is increased by the pressure of the gas filled in the tank, and the tank valve is closed in the first state.
By temporarily opening the discharge valve provided in the flow path from the first state, the gas in the closed space is discharged to the outside, and the pressure in the closed space is applied to the pressure in the first state. The pressure is reduced from the pressure, and the release valve is closed in the second state.
When the amount of decompression from the first state to the second state is less than a predetermined threshold value, the valve closing abnormality of the tank valve is caused by the change in pressure detected by the sensor after the valve closing of the release valve. Among the determination methods, the presence or absence of a valve closing abnormality of the tank valve is determined by the first determination method determined in advance.
When the decompression amount to the second state is equal to or greater than the threshold value, the presence or absence of the valve closing abnormality is determined by the second determination method, which is more accurate than the first determination method.
Valve abnormality judgment method.

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