JP2017145903A - Method for operating gas supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of sensors as small as possible and simplify the control.SOLUTION: A method for operating a hydrogen gas supply system 10 detects temperature of a second hydrogen tank 14b while a first solenoid valve 20a and a second solenoid valve 20b are open, and closes the first solenoid valve 20a or second solenoid valve 20b when it is determined that detected temperature of the second hydrogen tank 14b exceeds a lower limit threshold temperature or determined that the temperature exceeds an upper limit threshold temperature.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for operating a gas supply system that stores a gas and includes a plurality of gas tanks having different temperature change characteristics due to the movement of the gas.

  For example, a gas supply system mounted on a fuel cell vehicle may include a plurality of fuel tanks (gas tanks) and supply fuel gas from each fuel tank to the fuel cell stack.

  In this type of gas supply system, there is no need to provide a plurality of pressure sensors for detecting the tank pressure of each fuel tank, and the high pressure disclosed in Patent Document 1 is intended to reduce the cost and the weight of the device. Gas systems have been proposed. The high-pressure gas system includes a plurality of high-pressure gas tanks, and each high-pressure gas tank is provided with a shut-off valve and a temperature sensor.

  And after opening a plurality of shut-off valves in response to the valve opening request, when the temperature of the temperature signal output from any of the temperature sensors exceeds a predetermined temperature, other than the high pressure gas tank that outputs the temperature signal Another high pressure gas tank shut-off valve is closed.

  Accordingly, it is only necessary to provide a temperature sensor for each high-pressure gas tank, and it is not particularly necessary to provide a pressure sensor for each high-pressure gas tank, preventing an increase in the cost required for the device configuration and preventing an increase in the weight of the device. It can be done.

JP2013-253672A

  The present invention has been made in connection with this type of technology, and provides a method for operating a gas supply system capable of reducing the number of sensors as much as possible and simplifying control. The purpose is to do.

  A gas supply system to which an operation method according to the present invention is applied includes a plurality of gas tanks that store gas and have different temperature change characteristics due to movement of the gas, and a gas that circulates the gas supplied from the plurality of gas tanks And a flow path. Each gas tank is provided with a shut-off valve that allows and blocks gas flow between each gas tank and the gas flow path. A gas tank having the greatest temperature change due to gas movement is used as a measurement gas tank, and a temperature sensor is provided in the measurement gas tank.

  This operation method includes a step of detecting the temperature of the measurement gas tank in a state in which the shutoff valve provided in each gas tank is opened. This operation method is provided in the measurement gas tank or another gas tank when it is determined that the detected temperature of the measurement gas tank has changed by a predetermined value or more, or when it is determined that the temperature reaches a predetermined threshold. A step of closing the shut-off valve provided.

  Moreover, it is preferable that each gas tank is provided with a sealing member at a mouth portion through which gas enters and exits. At that time, when it is determined that the detected temperature of the gas tank for measurement is lower than the lower limit threshold temperature based on the seal characteristics of the seal member, the process has a step of closing the shut-off valve provided in the gas tank for measurement. Is preferred.

  Further, after closing the shut-off valve provided in the measurement gas tank, when the temperature of the measurement gas tank rises above a predetermined value, the shut-off valve provided in the measurement gas tank may be opened. preferable.

  Furthermore, when it is determined that the detected temperature of the measurement gas tank exceeds the upper threshold temperature based on the sealing characteristics of the seal member, it is preferable to close the shutoff valves provided in the other gas tanks.

  In addition, after closing the shut-off valve provided in another gas tank, when the temperature of the measurement gas tank drops by a predetermined value or more, it is preferable to open the shut-off valve provided in the other gas tank. .

  Furthermore, when temperature detection by the temperature sensor is impossible, it is preferable to close the shut-off valve provided in the measurement gas tank.

  According to the present invention, the temperature of the gas tank for measurement is detected in a state where the shut-off valve provided in each gas tank is opened. When it is determined that the detected temperature of the measurement gas tank has changed by a predetermined value or more, or when it is determined that the temperature has reached a predetermined threshold, a shut-off valve provided in the measurement gas tank or another gas tank is provided. The valve is closed.

  For this reason, it is only necessary to detect the temperature of the measurement gas tank, which is the gas tank having the largest temperature change due to the movement of the gas among the plurality of gas tanks. Therefore, the number of sensors can be reduced as much as possible, and the control can be simplified.

It is a schematic structure explanatory view of a hydrogen gas supply system to which an operation method concerning a 1st embodiment of the present invention is applied. It is a flowchart explaining the said driving | running method. In the said operation method, it is explanatory drawing of the relationship between the pressure and temperature at the time of hydrogen gas moving from a 2nd hydrogen tank to a 1st hydrogen tank. In the said operation method, it is explanatory drawing of the relationship between the pressure and temperature at the time of hydrogen gas moving from the said 1st hydrogen tank to the said 2nd hydrogen tank. It is schematic structure explanatory drawing of the hydrogen gas supply system which concerns on the 2nd Embodiment of this invention. It is schematic structure explanatory drawing of the hydrogen gas supply system which concerns on the 3rd Embodiment of this invention.

  As shown in FIG. 1, a hydrogen gas supply system (gas supply system) 10 to which an operation method according to the first embodiment of the present invention is applied is connected to a fuel cell stack 12, for example, a fuel cell electric vehicle. Mounted on.

  Although the fuel cell stack 12 is not shown, a plurality of power generation cells are stacked. The fuel cell stack 12 is supplied with hydrogen gas as a fuel gas from the hydrogen gas supply system 10 and with an oxidant gas (compressed air) from an air pump (compressor) (not shown).

  The hydrogen gas supply system 10 includes a plurality of first hydrogen tanks 14a and second hydrogen tanks 14b that are, for example, two high-pressure gas tanks that store hydrogen gas and have different temperature change characteristics due to movement of the hydrogen gas. The first hydrogen tank 14a constitutes a large tank having a large capacity, while the second hydrogen tank 14b constitutes a small tank having a smaller capacity than the first hydrogen tank 14a.

  The second hydrogen tank 14b is a gas tank having the largest temperature change due to the movement of hydrogen gas, and is hereinafter also referred to as a measurement hydrogen tank 14s.

  The first hydrogen tank 14a has a first mouth portion 16a through which hydrogen gas enters and exits, and a first electromagnetic valve (shutoff valve) 20a is interposed in the first mouth portion 16a via a first seal member 18a. Provided. The second hydrogen tank 14b has a second mouth portion 16b through which hydrogen gas enters and exits, and a second electromagnetic valve (shutoff valve) 20b is interposed in the second mouth portion 16b via a second seal member 18b. Provided.

  One end of the first flow path portion 22a is connected to the first electromagnetic valve 20a, and one end of the second flow path portion 22b is connected to the second electromagnetic valve 20b. The other end of the first flow path portion 22 a and the other end of the second flow path portion 22 b merge to provide a hydrogen gas flow path 22, and the hydrogen gas flow path 22 is a fuel gas of the fuel cell stack 12. It is connected to a (hydrogen gas) supply system (not shown). In the middle of the hydrogen gas flow path 22, the pressure sensor 24 and the regulator 26 are sequentially arranged along the hydrogen gas supply flow direction.

  The first hydrogen tank 14a is provided with a first temperature sensor 28a for detecting the hydrogen temperature in the first hydrogen tank 14a. The second hydrogen tank 14b (measuring hydrogen tank 14s) is provided with a second temperature sensor 28b for detecting the hydrogen temperature in the second hydrogen tank 14b.

  The first temperature sensor 28 a and the second temperature sensor 28 b are connected to the control unit 30. The control unit 30 receives the hydrogen temperature (temperature signal) in the second hydrogen tank 14b output from the second temperature sensor 28b, and performs opening / closing control of the first electromagnetic valve 20a and the second electromagnetic valve 20b.

  The operation of the hydrogen gas supply system 10 configured as described above will be described below.

  When supplying hydrogen gas to the fuel cell stack 12, the first electromagnetic valve 20a and the second electromagnetic valve 20b are opened by a control signal from the control unit 30. For this reason, the hydrogen gas in the first hydrogen tank 14a is supplied from the first flow path portion 22a to the hydrogen gas flow path 22. Similarly, the hydrogen gas in the second hydrogen tank 14b is supplied to the hydrogen gas passage 22 from the second passage portion 22b.

  Accordingly, the hydrogen gas that merges from the first flow path portion 22a and the second flow path portion 22b and flows through the hydrogen gas flow path 22 is adjusted in pressure by the regulator 26, and then is supplied to the fuel gas supply system of the fuel cell stack 12. Supplied. On the other hand, the oxidant gas supply system of the fuel cell stack 12 is supplied with compressed air as the oxidant gas. Thereby, in each power generation cell, the supplied fuel gas and the supplied oxidant gas are consumed by the electrochemical reaction to generate power.

  In the hydrogen gas supply system 10 described above, when the first hydrogen tank 14a or the second hydrogen tank 14b is replaced with a new (empty) tank, the first hydrogen tank 14a and the second hydrogen tank 14b There may be a pressure difference due to hydrogen gas during the period.

  Further, there is a case where a valve opening failure occurs in the first electromagnetic valve 20a or the second electromagnetic valve 20b and hydrogen is consumed, or a valve closing failure occurs and hydrogen consumption is not performed. For this reason, a pressure difference will generate | occur | produce between the 1st hydrogen tank 14a and the 2nd hydrogen tank 14b.

  Therefore, the operation method according to the first embodiment of the present invention is applied to the hydrogen gas supply system 10. This operation method will be described below along the flowchart shown in FIG.

  First, when the operation (power generation) of the fuel cell stack 12 is started, the first electromagnetic valve 20a and the second electromagnetic valve 20b are opened (step S1). The control unit 30 receives a temperature signal from the second temperature sensor 28b provided in the second hydrogen tank (measurement hydrogen tank 14s) 14b. When the control unit 30 detects the temperature of the second hydrogen tank 14b (YES in step S2), the control unit 30 proceeds to step S3 and determines whether or not the detected temperature is lowered.

  If it is determined that the detected temperature is decreasing (YES in step S3), the process proceeds to step S4, where the temperature decrease amount (−ΔTd) is a lower threshold temperature difference, for example, −20 ° C. to −30 ° C. It is determined whether or not it exceeds. When the detected temperature is decreasing, for example, as shown in FIG. 3, the pressure and temperature of the first hydrogen tank 14a and the pressure and temperature of the second hydrogen tank 14b vary. The control unit 30 detects only the temperature of the second hydrogen tank 14b, and detects the temperature difference from the start temperature to the descending temperature, that is, the temperature descending amount (−ΔTd).

  The phenomenon that the detected temperature of the second hydrogen tank 14b decreases appears when hydrogen gas is moved from the second hydrogen tank 14b to the first hydrogen tank 14a. Specifically, when the first electromagnetic valve 20a or the second electromagnetic valve 20b is caused to fail to close or open, or is replaced with an empty first hydrogen tank 14a, the second hydrogen tank 14b is This is a case where the pressure is higher than that of the first hydrogen tank 14a.

  For this reason, when the first electromagnetic valve 20a and the second electromagnetic valve 20b are opened after solving the problem, hydrogen gas flows from the high-pressure second hydrogen tank 14b to the low-pressure first hydrogen tank 14a. Accordingly, the internal temperature and the internal pressure of the second hydrogen tank 14b are reduced by releasing the hydrogen gas. At that time, a second seal member 18b is provided in the second mouth portion 16b of the second hydrogen tank 14b, and a seal guarantee lower limit temperature is set for the second seal member 18b. For example, when the outside air temperature is −30 ° C., the seal guarantee lower limit temperature is −40 ° C.

  Accordingly, when it is determined that the temperature decrease amount (−ΔTd) of the second hydrogen tank 14b exceeds the lower limit threshold temperature difference (YES in step S4), the process proceeds to step S5, and the second electromagnetic valve 20b is closed. To be spoken. For this reason, the release of hydrogen gas from the second hydrogen tank 14b is stopped, and the second seal member 18b can be protected.

  After the second electromagnetic valve 20b is closed, the routine proceeds to step S6, where it is determined whether or not the temperature of the second hydrogen tank 14b has increased by a predetermined value or more. When it is determined that the temperature of the second hydrogen tank 14b has increased by a predetermined value or more (YES in step S6), the process proceeds to step S7, and the second electromagnetic valve 20b is opened again.

  If it is determined in step S4 that the temperature decrease amount (−ΔTd) of the second hydrogen tank 14b does not exceed the lower limit threshold temperature difference (NO in step S4), the process proceeds to step S8. If it is determined in step S8 that the temperature decrease amount (−ΔTd) does not exceed the lower limit threshold temperature difference even after a predetermined time has elapsed (YES in step S8), the control is terminated.

  Further, in step S4, it may be determined whether or not the detected temperature has reached the lower limit threshold value instead of detecting the temperature decrease amount (−ΔTd). The lower limit threshold, which is a determination criterion, is a value obtained by placing a margin for sensor error on the lower limit threshold temperature. When the detected temperature reaches the lower limit threshold, the process proceeds to step S5. On the other hand, when the detected temperature does not reach the lower limit threshold, the process proceeds to step S8.

  On the other hand, if it is determined in step S3 that the temperature detected by the second temperature sensor 28b has not decreased (NO in step S3), the process proceeds to step S9 to determine whether or not the detected temperature has increased. The

  If it is determined that the detected temperature has increased (YES in step S9), the process proceeds to step S10, and whether or not the temperature increase amount (ΔTi) exceeds an upper threshold temperature difference, for example, 40 ° C to 50 ° C. Is judged. When the detected temperature is rising, for example, as shown in FIG. 4, the pressure and temperature of the first hydrogen tank 14a and the pressure and temperature of the second hydrogen tank 14b vary. The control unit 30 detects only the temperature of the second hydrogen tank 14b, and detects the temperature difference from the start temperature to the rising temperature, that is, the temperature increase amount (ΔTi).

  When the detected temperature is rising, for example, as shown in FIG. 4, the pressure and temperature of the first hydrogen tank 14a and the pressure and temperature of the second hydrogen tank 14b vary. The control unit 30 detects only the temperature of the second hydrogen tank 14b, and detects the temperature difference from the start temperature to the rising temperature, that is, the temperature increase amount (ΔTi).

  The phenomenon that the detected temperature of the second hydrogen tank 14b rises appears when hydrogen gas moves from the first hydrogen tank 14a to the second hydrogen tank 14b. Specifically, when the first electromagnetic valve 20a or the second electromagnetic valve 20b is caused to have a poor closing or a poor opening, or is replaced with an empty second hydrogen tank 14b, the first hydrogen tank 14a This is a case where the pressure is higher than that of the second hydrogen tank 14b.

  For this reason, when the first solenoid valve 20a and the second solenoid valve 20b are opened after solving the problem, the hydrogen gas flows from the high-pressure first hydrogen tank 14a to the low-pressure second hydrogen tank 14b. Accordingly, the internal temperature and the internal pressure of the second hydrogen tank 14b are increased by supplying the hydrogen gas.

  At that time, a second seal member 18b is provided in the second mouth portion 16b of the second hydrogen tank 14b, and a seal guarantee upper limit temperature is set for the second seal member 18b. For example, when the outside air temperature is 40 ° C., the seal guarantee upper limit temperature is 85 ° C.

  Accordingly, when it is determined that the temperature increase amount (ΔTi) of the second hydrogen tank 14b exceeds the upper limit threshold temperature difference (YES in step S10), the process proceeds to step S11, and the first electromagnetic valve 20a is closed. Is done. For this reason, the release of hydrogen gas from the first hydrogen tank 14a is stopped, and the second seal member 18b can be protected.

  After the first electromagnetic valve 20a is closed, the routine proceeds to step S12, where it is determined whether or not the temperature of the second hydrogen tank 14b has dropped by a predetermined value or more. When it is determined that the temperature of the second hydrogen tank 14b has dropped by a predetermined value or more (YES in step S12), the process proceeds to step S13, and the first electromagnetic valve 20a is opened again.

  If it is determined in step S10 that the temperature increase amount (ΔTi) of the second hydrogen tank 14b does not exceed the upper limit threshold temperature difference (NO in step S10), the process proceeds to step S14. In step S14, if it is determined that the temperature rise amount (ΔTi) does not exceed the upper limit threshold temperature difference even after a predetermined time has elapsed (YES in step S14), the control is terminated.

  By the way, in step S10, it may be determined whether or not the detected temperature has reached the upper limit threshold value instead of the detection of the temperature increase amount (ΔTi). The upper limit threshold that is a criterion is a value obtained by putting a margin of sensor error on the upper limit threshold temperature. When the detected temperature reaches the upper limit threshold, the process proceeds to step S11, but when the detected temperature does not reach the upper limit threshold, Proceed to S14.

  If it is determined in step S2 that temperature detection by the second temperature sensor 28b is impossible (NO in step S2), the process proceeds to step S15, and the second electromagnetic valve 20b is closed.

  In this case, in the first embodiment, the temperature of the second hydrogen tank 14b, which is the measurement hydrogen tank 14s, is detected with the first electromagnetic valve 20a and the second electromagnetic valve 20b opened. Then, when it is determined that the detected temperature decrease amount (−ΔTd) of the second hydrogen tank 14b exceeds the lower limit threshold temperature difference, or the temperature increase amount (ΔTi) is determined to exceed the upper limit threshold temperature difference. In this case, the first electromagnetic valve 20a or the second electromagnetic valve 20b is closed. Alternatively, when it is determined that the detected temperature of the second hydrogen tank 14b has reached the lower limit threshold value, or when it is determined that the detected temperature has reached the upper limit threshold value, the first electromagnetic valve 20a or the second electromagnetic valve 20b is closed. .

  For this reason, if the temperature of the second hydrogen tank (measurement hydrogen tank 14s) 14b having the largest temperature change due to gas movement is detected among the first hydrogen tank 14a and the second hydrogen tank 14b, which are a plurality of gas tanks. Good. Therefore, only the second hydrogen tank 14b needs to be monitored, the number of sensors can be reduced as much as possible, and the control by the control unit 30 can be easily simplified.

  The second hydrogen tank 14b is provided with a second seal member 18b at the second mouth portion 16b through which hydrogen gas enters and exits. At that time, if it is determined that the detected temperature of the second hydrogen tank 14b is lower than the lower limit threshold temperature based on the seal characteristic of the second seal member 18b, the second electromagnetic valve 20b is closed. Thereby, the sealing function of the 2nd sealing member 18b can be protected reliably.

  Further, after the second electromagnetic valve 20b is closed, the second electromagnetic valve 20b is opened when the temperature of the second hydrogen tank 14b rises by a predetermined value or more. For this reason, it can be determined that the hydrogen gas supply system 10 has returned to normal, and no unnecessary maintenance or restriction is performed. Therefore, user convenience is effectively improved.

  Furthermore, when it is determined that the detected temperature of the second hydrogen tank 14b exceeds the upper threshold temperature based on the sealing characteristics of the second seal member 18b, the first electromagnetic valve 20a of the first hydrogen tank 14a is closed. It is spoken. Thereby, it becomes possible to reliably protect the sealing function of the second seal member 18b.

  In addition, after the first electromagnetic valve 20a is closed, the first electromagnetic valve 20a is opened when the temperature of the second hydrogen tank 14b drops by a predetermined value or more. For this reason, it can be determined that the hydrogen gas supply system 10 has returned to normal, and no unnecessary maintenance or restriction is performed. Therefore, user convenience is effectively improved.

  Furthermore, when temperature detection by the second temperature sensor 28b is impossible, the second electromagnetic valve 20b of the second hydrogen tank 14b is closed. Thereby, there is a possibility that a failure has occurred in the second temperature sensor 28b, and it becomes possible to protect the second hydrogen tank 14b by closing the second hydrogen tank 14b having a large temperature change in advance.

  FIG. 5 is an explanatory diagram of a schematic configuration of a hydrogen gas supply system 40 according to the second embodiment of the present invention. In addition, the same reference number is attached | subjected to the component same as the hydrogen gas supply system 10 which concerns on 1st Embodiment, and the detailed description is abbreviate | omitted.

  The hydrogen gas supply system (gas supply system) 40 includes one first hydrogen tank 14a and two second hydrogen tanks 14b1 and 14b2. The second hydrogen tanks 14b1 and 14b2 are provided with a second electromagnetic valve 20b and a second temperature sensor 28b, respectively.

  In the hydrogen gas supply system 40 configured as described above, the same effects as those of the first embodiment can be obtained by detecting the temperatures of the second hydrogen tanks 14b1 and 14b2.

  FIG. 6 is an explanatory diagram of a schematic configuration of a hydrogen gas supply system 50 according to the third embodiment of the present invention. In addition, the same reference number is attached | subjected to the component same as the hydrogen gas supply system 10 which concerns on 1st Embodiment, and the detailed description is abbreviate | omitted.

  The hydrogen gas supply system (gas supply system) 50 includes a plurality of, for example, three high-pressure gas tanks, ie, a first hydrogen tank 14a, a second hydrogen tank 14b, and a third hydrogen tank 14c, having different temperature change characteristics due to movement of hydrogen gas. Prepare. The capacity is set smaller in the order of the first hydrogen tank 14a, the second hydrogen tank 14b, and the third hydrogen tank 14c.

  In the hydrogen gas supply system 50 configured as described above, the temperatures of the second hydrogen tank 14b, which is an intermediate tank, and the third hydrogen tank 14c, which is a small tank, may be detected. For this reason, the first temperature sensor 28a may not be provided in the first hydrogen tank 14a which is a large tank.

DESCRIPTION OF SYMBOLS 10, 40, 50 ... Hydrogen gas supply system 12 ... Fuel cell stack 14a, 14b, 14b1, 14b2, 14c ... Hydrogen tank 14s ... Hydrogen tank for measurement 16a, 16b ... Mouth part 18a, 18b ... Sealing member 20a, 20b ... Electromagnetic Valve 22 ... Hydrogen gas flow path 22a, 22b ... Flow path section 24 ... Pressure sensor 26 ... Regulator 28a, 28b ... Temperature sensor 30 ... Control section

Claims (6)

A plurality of gas tanks that store gas and have different temperature change characteristics due to movement of the gas,
A gas flow path for circulating the gas supplied from the plurality of gas tanks;
A shut-off valve provided in each gas tank, which allows and shuts off the flow of the gas between each gas tank and the gas flow path;
A gas tank having the largest temperature change due to the movement of the gas as a measurement gas tank, and a temperature sensor provided in the measurement gas tank;
A gas supply system operating method comprising:
A step of detecting the temperature of the gas tank for measurement in a state where the shut-off valve provided in each gas tank is opened;
When it is determined that the detected temperature of the measurement gas tank has changed by a predetermined value or more, or when it is determined that a predetermined threshold value has been reached, the cutoff valve provided in the measurement gas tank or another gas tank is Closing the valve;
A method for operating a gas supply system, comprising: The operation method according to claim 1, wherein each gas tank is provided with a seal member at a mouth portion where the gas enters and exits,
Closing the shut-off valve provided in the measurement gas tank when it is determined that the detected temperature of the measurement gas tank is lower than a lower limit threshold temperature based on a seal characteristic of the seal member;
A method for operating a gas supply system, comprising:   3. The operation method according to claim 2, wherein after the shutoff valve provided in the measurement gas tank is closed, when the temperature of the measurement gas tank rises by a predetermined value or more, the measurement gas tank is provided with the measurement gas tank. A method for operating a gas supply system, wherein the shut-off valve is opened.   4. The operation method according to claim 2, wherein when it is determined that the detected temperature of the gas tank for measurement exceeds an upper threshold temperature based on a seal characteristic of the seal member, the gas tank is provided in the other gas tank. A method for operating a gas supply system, wherein the shut-off valve is closed.   5. The operation method according to claim 4, wherein after the shutoff valve provided in the other gas tank is closed, when the temperature of the measurement gas tank drops by a predetermined value or more, the operation is provided in the other gas tank. A method for operating a gas supply system, wherein the shut-off valve is opened.   The operation method according to any one of claims 1 to 5, wherein when the temperature detection by the temperature sensor is impossible, the shut-off valve provided in the measurement gas tank is closed. To operate the gas supply system.

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