High-pressure gas supply device

Abstract

The disclosure herein provides a technique for a high-pressure gas supply device capable of supplying high-pressure gas from a plurality of gas tanks, in which it is possible to easily check whether or not gas leakage has occurred at a main stop valve of each of the plurality of gas tanks.SOLUTION: A high-pressure gas supply device disclosed in the present specification includes a plurality of gas tanks each having a main stop valve and storing high-pressure gas, a gas pipe connecting a gas outlet and the main stop valve of each of the plurality of gas tanks, a pressure sensor measuring an internal pressure of the gas pipe, and a controller controlling each of the main stop valves. The controller sequentially repeats a process of sending a valve opening command to one of the main stop valves each time the internal pressure of the gas pipe becomes constant, and when the internal pressure does not change immediately after the valve opening command is sent to any of the main stop valves, the controller outputs a signal indicating that a gas leak has occurred in any of the main stop valves.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a high-pressure gas supply device capable of supplying high-pressure gas from a plurality of gas tanks. [Background technology]

[0002] In many cases, devices that use gas tanks that store high-pressure gas are equipped with a mechanism for detecting gas leaks from the gas tank's main stop valve. Patent Document 1 discloses a technology that prevents the internal pressure of a fuel gas supply pipe from falling below a gas leak detection standard pressure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-96533 Summary of the Invention [Problem to be solved by the invention]

[0004] A high-pressure gas supply device may be equipped with multiple gas tanks. The main stop valves of the multiple gas tanks are connected to a single gas outlet by gas pipes. This specification provides a technology that can easily check whether gas leaks are occurring at the main stop valves of the multiple gas tanks. [Means for solving the problem]

[0005] The high-pressure gas supply device disclosed in this specification comprises a plurality of gas tanks each having a main stop valve and storing high-pressure gas, a gas pipe connecting a gas outlet to each of the main stop valves of the plurality of gas tanks, a pressure sensor that measures the internal pressure of the gas pipe, and a controller that controls each of the main stop valves.

[0006] The controller sequentially repeats the process of sending an open command to one of the main stop valves each time the internal pressure of the gas pipe becomes constant, and if the internal pressure does not change immediately after sending an open command to any of the main stop valves, it outputs a signal indicating that a gas leak is occurring in that main stop valve.

[0007] If the internal pressure does not increase immediately after sending the valve open command, it is determined that the main stop valve to which the valve open command was sent is leaking gas. This is because, at the main stop valve where the gas is leaking, the pressure in the gas tank is equal to the internal pressure of the gas pipe before the valve open command is sent. The high-pressure gas supply device disclosed in this specification sends an open valve command to each main stop valve each time the internal pressure of the gas supply pipe becomes constant. This process makes it easy to check for gas leaks at each of the multiple main stop valves.

[0008] Details and further improvements of the technology disclosed in this specification are described in the following "Description of Embodiments of the Invention." [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram of a high-pressure gas supply device according to an embodiment. [Figure 2] 10 is a flowchart of a gas supply start process executed by a controller. [Figure 3] 10 is a time chart of internal pressure changes (when all main stop valves are normal). [Figure 4] 10 is a time chart of internal pressure changes (when one main stop valve has an open failure). [Figure 5] This is a time chart of internal pressure changes (when another main stop valve has an open failure). DETAILED DESCRIPTION OF THE INVENTION

[0010] A high-pressure gas supply apparatus 10 according to an embodiment will be described with reference to the drawings. FIG. 1 shows a block diagram of the high-pressure gas supply apparatus 10. In the example of FIG. 1, the high-pressure gas supply apparatus 10 supplies gas to a gas-utilizing device 30. In the example of FIG. 1, the high-pressure gas supplied by the high-pressure gas supply apparatus 10 is hydrogen gas, and the gas-utilizing device 30 is a fuel cell. The gas-utilizing device 30 (fuel cell) includes a large gas tank 32 and a fuel cell stack 34. The high-pressure gas supply apparatus 10 discharges gas from a gas outlet 13. In the example of FIG. 1, the gas outlet 13 and the gas tank 32 of the gas-utilizing device 30 are connected by an external gas pipe 31. The gas outlet 13 is an opening to which the gas-utilizing device 30 is connected. A stop valve 33 that closes the external gas pipe 31 is also provided on the gas-utilizing device 30 side. Note that a fuel cell is one example of the gas-utilizing device 30, and the gas-utilizing device 30 may be a device other than a fuel cell.

[0011] The high-pressure gas supply device 10 has four gas tanks (first gas tank 11a to fourth gas tank 11d). For ease of explanation, when referring to any of the four gas tanks without distinction or when referring to all of the gas tanks collectively, it will be referred to as gas tank 11. Each gas tank is filled with high-pressure hydrogen gas. The first gas tank 11a is provided with a first main stop valve 12a. The other gas tanks 11 are also provided with main stop valves 12. For ease of explanation, when referring to any of the first main stop valve 12a to fourth main stop valve 12d without distinction or when referring to all of the main stop valves collectively, it will be referred to as main stop valve 12. When the main stop valve 12 is opened, high-pressure gas is released from the gas tank 11. When the main stop valve 12 is closed, the discharge of gas stops. The main stop valve 12 is controlled by a controller 17. The measurement value of the pressure sensor 16 (that is, the internal pressure of the gas pipe 14) described later is sent to the controller 17.

[0012] The high-pressure gas supply device 10 includes a gas pipe 14 connecting four gas tanks 11 and gas outlets 13. One end of the gas pipe 14 is connected to the gas outlets 13, and the other end is connected to the main stop valves 12 of each gas tank 11. The gas pipe 14 is equipped with a pressure sensor 16. The pressure sensor 16 measures the internal pressure of the gas pipe 14. A supply valve 15 is provided in the gas pipe 14 near the gas outlet 13, and the pressure sensor 16 is attached to the gas pipe 14 closer to the main stop valve 12 than the supply valve 15. In other words, the pressure sensor 16 measures the internal pressure of the gas pipe 14 between the main stop valve 12 and the supply valve 15. The supply valve 15 is a valve that stops the discharge of gas from the gas outlet 13.

[0013] The main stop valve 12 and the supply valve 15 are electromagnetic valves and are controlled by the controller 17. The main stop valve 12 and the supply valve 15 open when they receive an open valve command from the controller 17, and close when they receive a close valve command. Even if one of the multiple main stop valves 12 fails and remains open, gas will not leak to the outside as long as the supply valve 15 is closed. A state in which a valve remains open regardless of a command from the controller 17 is called an open valve failure. An "open valve failure" is synonymous with a "gas leak."

[0014] Prior to supplying gas to the outside, the controller 17 checks whether any of the main stop valves 12 have a gas leak. The controller 17 executes a gas supply start process that includes a gas leak check. If a gas leak is detected in any of the main stop valves 12 during the gas supply start process, the controller 17 stops the supply of gas to the outside and sends a signal (gas leak occurrence signal) to the display device 18 to notify the display device 18 of the occurrence of a gas leak. Upon receiving the gas leak occurrence signal, the display device 18 displays a message indicating that a gas leak has occurred. Note that the controller 17 may send the gas leak occurrence signal to another device (for example, a device that manages the high-pressure gas supply device 10) instead of the display device 18. The gas leak occurrence signal may include data indicating which main stop valve is leaking.

[0015] 2 shows a flowchart of the gas supply start process executed by the controller 17. The gas supply start process will be described with reference to FIG. 2. Note that the supply valve 15 is closed before the gas supply start process. Before the gas supply start process, the controller 17 also sends a valve close command to all of the main stop valves 12, and all of the main stop valves 12 are closed prior to the gas supply start process. However, if any of the main stop valves 12 has an open failure, there may be a main stop valve 12 that is not completely closed despite receiving a valve close command.

[0016] First, the controller 17 assigns 1 to a variable i in the program (step S2). The variable i is an integer that specifies the gas tank 11 and the main stop valve. For example, i=1 represents the first gas tank 11a and the first main stop valve 12a. i=4 represents the fourth gas tank 11d and the fourth main stop valve 12d. The total number of gas tanks 11 is represented by a constant N.

[0017] The controller 17 sends a valve open command to the ith main stop valve 12 (step S3). Then, the controller 17 monitors the measurement value of the pressure sensor 16 and determines whether the internal pressure of the gas pipe 14 has increased (step S4). If the internal pressure of the gas pipe 14 has increased immediately after the ith main stop valve 12 is opened (step S4: YES), it is determined that high-pressure gas has moved from the ith gas tank 11 to the gas pipe 14. In other words, it is determined that the ith main stop valve 12 was properly closed before the valve open command was sent to the ith main stop valve 12 (it is determined that no gas leak is occurring at the ith main stop valve 12).

[0018] Conversely, if the internal pressure of the gas pipe 14 does not increase immediately after sending the valve open command to the i-th main stop valve 12 (step S4: NO), it is determined that the i-th main stop valve 12 had an open malfunction before sending the valve open command. If the determination in step S4 is "NO" (i.e., the i-th main stop valve 12 has an open malfunction), the controller 17 sends a signal notifying the display device 18 of the occurrence of a gas leak in the i-th main stop valve 12 (step S9). As described above, upon receiving the signal, the display device 18 displays a message warning that a gas leak has occurred in the i-th main stop valve 12. The controller 17 then executes a response process in response to the occurrence of a gas leak (abnormality response process, step S10) and terminates the process. The abnormality response process is, for example, a process of sending a signal to the connected gas usage device 30 notifying that the start of gas supply has been interrupted, or sending a signal indicating the occurrence of a gas leak to a device that manages the high-pressure gas supply apparatus 10.

[0019] If an increase in internal pressure is detected in step S4 (step S4: YES), the controller 17 waits until the increase in internal pressure stops (step S5). When the internal pressure of the i-th gas tank 11 and the internal pressure of the gas pipe 14 become equal, the increase in internal pressure of the gas pipe 14 stops.

[0020] When the controller 17 detects that the internal pressure increase has stopped, if the variable i is less than N, it adds 1 to the variable i and repeats the processes from step S3 to S5 (step S6: NO, S7). That is, the controller 17 sequentially repeats the process of sending an open valve command to one main stop valve 12 each time the internal pressure of the gas pipe 14 becomes constant. If the controller 17 cannot detect an internal pressure increase after sending the open valve command, it detects that a gas leak has occurred in the main stop valve 12 to which the open valve command was sent. In this case, the controller 17 sends a signal to the display device 18 to notify the occurrence of a gas leak.

[0021] After sending the open command to all the main stop valves 12, if an increase in internal pressure is detected, it is determined that no gas leaks are occurring in any of the main stop valves 12, and the controller 17 sends an open command to the supply valve 15 (step S6: YES, S8). When the supply valve 15 opens, gas supply from the multiple gas tanks 11 to the gas utilization device 30 begins.

[0022] In this way, the high-pressure gas supply apparatus 10 performs a gas leak check on all main stop valves 12 before starting to supply high-pressure gas to the gas-using device 30 .

[0023] 3 shows a time chart of the internal pressure change when all the main stop valves 12 are normal. The initial internal pressure P0 is the internal pressure of the gas pipe 14 after a valve close command is sent to all the main stop valves 12.

[0024] At time T1, the controller 17 sends a valve open command to the main stop valve (first main stop valve 12a) of the first gas tank 11a. When the first main stop valve 12a opens, gas from the first gas tank 11a flows into the gas pipe 14, and the internal pressure of the gas pipe 14 increases. In other words, it is determined that the first main stop valve 12a was normally closed before the valve open command was sent. At times T2, T3, and T4, the controller 17 sends a valve open command to the corresponding main stop valve 12. In the example of FIG. 3, the internal pressure of the gas pipe 14 increases immediately after the valve open command is sent, and therefore it is determined that all of the main stop valves 12 are normal.

[0025] 4 shows a time chart of internal pressure changes when a gas leak occurs at the first main stop valve 12a. If a gas leak occurs at the first main stop valve 12a before a valve open command is sent, the internal pressure of the first gas tank 11a and the internal pressure of the gas pipe 14 are equal. Therefore, even if the controller 17 sends a valve open command to the first main stop valve 12a at time T1, the internal pressure of the gas pipe 14 does not change (the point indicated by arrow A in FIG. 4). In this case, the controller 17 detects that a gas leak has occurred at the first main stop valve 12a, and executes the processes of steps S9 and S10 in FIG. 2.

[0026] 5 shows a time chart of internal pressure changes when a gas leak occurs at the fourth main stop valve 12d. An internal pressure increase is detected immediately after the first main stop valve 12a through the third main stop valve 12c are opened, indicating that the first main stop valve 12a through the third main stop valve 12c are operating normally. When a gas leak occurs at the fourth main stop valve 12d, the internal pressure of the gas pipe 14 does not change even when the controller 17 sends an open command to the fourth main stop valve 12d at time T4 (the location indicated by arrow B in FIG. 5). In this case, the controller 17 detects that a gas leak has occurred at the fourth main stop valve 12d, and executes the processes of steps S9 and S10 in FIG. 2.

[0027] As described above, the high-pressure gas supply apparatus 10 can perform a gas leak check of all the main stop valves 12 every time the supply of high-pressure gas to the external gas-using device 30 is started.

[0028] Here are some points to note regarding the technology described in the embodiments. The initial internal pressure P0 may vary in Figures 3 to 5. The initial internal pressure P0 depends on the amount of gas remaining in the gas tank 11 when the most recent gas supply process ended. The initial internal pressure P0 also varies depending on whether a gas leak is occurring in any of the main stop valves 12.

[0029] If the supply valve 15 is closed prior to the gas supply start process, even if all main stop valves 12 are normally closed, it is possible that the internal pressure of the gas pipe 14 and the internal pressure of each gas tank 11 are equal. For example, this may occur if, at the end of all gas supply cycles, all main stop valves 12 are closed after the supply valve 15 is closed. In this case, the controller 17 may send an open command to the supply valve 15 at the beginning of the gas supply start process. By opening the supply valve 15 prior to sending the first open command to the main stop valve, some of the gas remaining in the gas pipe 14 flows to the external gas pipe 31 or the gas utilization device 30. This causes the internal pressure of the gas pipe 14 to drop. In other words, the internal pressure of the gas pipe 14 drops below the internal pressure of any of the gas tanks 11. By starting the process of FIG. 2 from this point, the controller 17 can always detect a gas leak from the main stop valve 12. The process of the controller 17 in this case is as follows. (1) The controller 17 sends an open valve command to the supply valve 15 before sending an open valve command to the main stop valve 12. When the internal pressure of the gas pipe 14 and the internal pressure of the external gas pipe 31 become equal, the change in the internal pressure of the gas pipe 14 stops. (2) The controller 17 sequentially repeats the process of sending an open valve command to one main stop valve 12 each time the internal pressure of the gas pipe 14 becomes constant. (3) If the internal pressure of the gas pipe 14 does not change after sending an open valve command to a specific main stop valve 12, the controller 17 outputs a signal indicating that a gas leak has occurred in the main stop valve to which the open valve command was sent. In this case, the open valve command is sent to the supply valve 15 first, so step S8 in Figure 2 is unnecessary.

[0030] To further enhance safety, the controller 17 may not only send an open command to the supply valve 15 at the beginning of the gas supply start process, but may also send a close command to the supply valve 15 next. In other words, the controller 17 sends an open command to the supply valve 15 at the beginning of the gas supply start process, and then sends a close command to the supply valve 15. By temporarily opening the supply valve 15, the internal pressure of the gas pipe 14 becomes lower than the internal pressure of any of the gas tanks 11. At this time, even if a gas leak occurs in any of the main stop valves 12, the supply valve 15 is closed, so only a small amount of gas leaks outside the high-pressure gas supply device 10.

[0031] The controller 17 may change the main stop valve to which the valve open command is sent first for each gas supply start process. Furthermore, the controller 17 may change the order of the main stop valves to which the valve open command is sent for each gas supply start process.

[0032] The high-pressure gas supply device 10 of the embodiment has four gas tanks 11. The technology disclosed in this specification is applicable to high-pressure gas supply devices having two or more gas tanks. The high-pressure gas supply device 10 may store gases other than hydrogen gas.

[0033] Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives alone is technically useful. [Explanation of symbols]

[0034] 10: High-pressure gas supply device 11, 11a-11d: Gas tank 12, 12a-12d: Main stop valve 13: Gas outlet 14: Gas pipe 15: Supply valve 16: Pressure sensor 17: Controller 18: Display device 30: Gas utilization device 31: External gas pipe 32: Gas tank 33: Stop valve 34: Fuel cell stack

Claims

[Claim 1] a plurality of gas tanks each having a main stop valve and storing high-pressure gas; a gas pipe connecting a gas outlet and the main stop valve of each of the plurality of gas tanks; a pressure sensor that measures the internal pressure of the gas pipe; a controller for controlling each of the main stop valves; It is equipped with The controller sequentially repeats the process of sending a valve open command to one of the main stop valves each time the internal pressure becomes constant, and outputs a signal indicating the occurrence of a gas leak if the internal pressure does not change immediately after sending the valve open command to any of the main stop valves. High pressure gas supply equipment.

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