Hydrogen gas supply system

Abstract

To provide a hydrogen gas supply system which can be operated at low cost and can be miniaturized.SOLUTION: A system for supplying hydrogen gas (H) from a supply source tank (3) for storing the compressed hydrogen gas (H) to a low-pressure filled tank (5) as a supply destination includes a supply passage (11) having a main passage (12) and a branch passage (13) and allowing the hydrogen gas (H) to pass therethrough, an expander (15) provided upstream of a branch point (17) of the branch passage (13) and expanding the hydrogen gas (H), a heat accumulator (19) provided in the branch passage (13) and accumulating cold heat of the hydrogen gas (H), a flow regulating valve (51) provided at the branch point (17) and regulating a flow rate of the hydrogen gas (H) in the branch passage (13), a supply gas temperature acquisition device (27) for acquiring a temperature of the hydrogen gas (H) supplied to the filled tank (5), and a tank temperature acquisition device (29) for acquiring a temperature in the filled tank (5).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a system for supplying hydrogen gas.

Background Art

[0002] In recent years, in order to suppress the emission of carbon dioxide, which causes environmental problems such as global warming, the development of technologies for using hydrogen as a fuel for vehicles and the like has been promoted toward the realization of a so-called low-carbon society.

[0003] When filling a hydrogen tank of a vehicle with hydrogen gas, if the filling is performed rapidly, the hydrogen gas in the tank is adiabatically compressed and the temperature rises, leading to a reduction in the life of the tank. Therefore, generally, the temperature of the hydrogen gas is lowered to about -40°C by a process called precooling, and then the tank is filled. As a precooling method, for example, as described in Patent Document 1, it has been proposed to use a refrigerator.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the use of a refrigerator not only increases the initial cost of the hydrogen gas supply facility, but also increases the running cost due to high power consumption. In addition, since the refrigerator is not suitable for intermittent operation, when the use of hydrogen fuel has not been sufficiently popularized and continuous demand cannot necessarily be expected, it causes a decrease in the business efficiency of the hydrogen gas supply facility. Further, generally, since the refrigerator is large in size, the adoption of the refrigerator increases the size of the entire system.

[0006] Therefore, the purpose of this disclosure is to provide a hydrogen gas supply system that can be operated at low cost and miniaturized in order to solve the above-mentioned problems. [Means for solving the problem]

[0007] To achieve the above objectives, the hydrogen gas supply system relating to this disclosure is A system for supplying hydrogen gas from a source tank that stores compressed hydrogen gas to a tank to be filled, which is at a lower pressure than the source tank, The aforementioned supply source tank, A supply passage for passing hydrogen gas from the supply source tank to the tank to be filled, comprising a main passage and branch passages that branch off and merge with each other along the way, An expander for expanding the hydrogen gas is provided in the supply passage, in the portion upstream of the branching point of the branch passage, A heat storage device is provided in the aforementioned branch passage for storing the cold energy of the hydrogen gas, A flow control valve is provided at the branching point in the supply passage to adjust the flow rate of hydrogen gas in the branch passage, A supply gas temperature acquisition device that acquires the temperature of the hydrogen gas supplied to the tank to be filled, A tank temperature acquisition device that acquires the temperature inside the tank to be filled, It is equipped with. [Effects of the Invention]

[0008] The hydrogen gas supply system described in this disclosure enables low-cost operation and miniaturization. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows a schematic configuration of a hydrogen gas supply system according to one embodiment of the present disclosure. [Figure 2] Figure 1 is a cross-sectional view showing the schematic structure of a heat storage device used in the hydrogen gas supply system. [Figure 3A]This figure shows an example of an operating method for a hydrogen gas supply system according to one embodiment of the present disclosure. [Figure 3B] This figure shows an example of an operating method for a hydrogen gas supply system according to one embodiment of the present disclosure. [Figure 3C] This figure shows an example of an operating method for a hydrogen gas supply system according to one embodiment of the present disclosure. [Figure 4] This block diagram shows a modified example of the hydrogen gas supply system shown in Figure 1. [Figure 5] This block diagram shows other variations of the hydrogen gas supply system shown in Figure 1. [Modes for carrying out the invention]

[0010] Preferred embodiments of the present disclosure will be described below with reference to the drawings. Figure 1 shows a hydrogen gas supply system 1 according to one embodiment of the present disclosure. This hydrogen gas supply system 1 is a system that supplies hydrogen gas H from a supply source tank 3 that stores hydrogen gas to a tank to be filled 5, which is the supply destination. In this embodiment, an example will be described in which the tank to be filled 5 is the fuel tank of a fuel cell vehicle 7.

[0011] The hydrogen gas supply system 1 supplies hydrogen gas H to the tank to be filled 5 by utilizing the pressure difference between the two tanks 3 and 5. The source tank 3 stores hydrogen gas H compressed to a high pressure, for example, about 82 MPa. The tank to be filled 5 is at a lower pressure than the source tank 3, for example, a few MPa when empty, for example, about 1 MPa.

[0012] The hydrogen gas supply system 1 includes a supply passage 11 that allows hydrogen gas H to pass from the supply source tank 3 to the tank to be filled 5. The supply passage 11 has a main passage 12 and branch passages 13 that branch off and merge with each other along the way.

[0013] The supply passage 11 is provided with an expander 15 for expanding the hydrogen gas H. The expander 15 is provided in an upstream portion of the supply passage 11 from a branch point 17 of the branch passage 13. The expander 15 recovers the expansion energy of the hydrogen gas H flowing in from the supply source tank 3 as power. By passing through the expander 15, the pressure and temperature of the hydrogen gas H decrease. However, as the supply of hydrogen gas to the filled tank 5 progresses and the differential pressure between the supply source tank 3 and the filled tank 5 decreases, the degree of temperature decrease becomes smaller, and the temperature of the hydrogen gas H discharged from the expander 15 gradually increases.

[0014] In this embodiment, a reciprocating expander is used as the expander 15. By using a reciprocating expander, a desired expansion ratio can be obtained with a compact size. However, the expander 15 may be other types of expanders. Also, in FIG. 1, an example in which the expander 15 has a single-stage configuration is shown, but it may be configured in a plurality of stages as appropriate according to the required pressure of the hydrogen gas H and the capacity of the expander 15 to be used.

[0015] The branch passage 13 of the supply passage 11 is provided with a heat accumulator 19 for storing the cold heat of the hydrogen gas H. The heat accumulator 19 is thermally connected to the branch passage 13, stores the cold heat of the hydrogen gas H passing through the branch passage 13, and cools the hydrogen gas H passing through the branch passage 13 by the cold heat thus stored. In this embodiment, as shown in FIG. 2, the heat accumulator 19 includes a large number of solid heat storage materials 21. As the solid heat storage material 21, it is preferable to use a substance having low reactivity with hydrogen and a large specific heat. In this example, rocks such as granite and silica crushed to an appropriate size are used as the solid heat storage material 21. However, the solid heat storage material 21 is not limited to this example.

[0016] Specifically, the heat accumulator 19 according to this embodiment includes a cylindrical metal casing 23, a heat insulating material 25 provided cylindrically on the inner peripheral surface of the casing 23, and the plurality of solid heat storage materials 21 filled inside the heat insulating material 25. A gap formed between the plurality of solid heat storage materials 21 serves as a flow path for hydrogen gas H. However, the specific configuration of the heat accumulator 19 is not limited to this example.

[0017] As shown in FIG. 1, the hydrogen gas supply system 1 according to this embodiment includes a supply gas temperature acquisition device 27 that acquires the temperature of the hydrogen gas H supplied to the filled tank 5, and a tank temperature acquisition device 29 that acquires the temperature inside the filled tank 5. In this specification, "acquiring the temperature" includes, in addition to the process of directly measuring the value of the temperature, the process of receiving data measured by other measuring instruments, and the process of calculating an estimated value based on other measurement data.

[0018] In this embodiment, as the supply gas temperature acquisition device 27, a first thermometer 31 that measures the temperature of the hydrogen gas H supplied to the filled tank 5 is provided in the supply passage 11. Further, a second thermometer 33 that measures the temperature of the hydrogen gas H discharged from the expander 15 is provided. In the illustrated example, the first thermometer 31 is disposed in a portion of the supply passage 11 downstream of the confluence point 35 with the branch passage 13. The second thermometer 33 is provided in a portion of the supply passage 11 between the expander 15 and the branch point 17. The specific mode of the supply gas temperature acquisition device 27 is not limited to this example, and for example, it may be a device that calculates an estimated value from the measurement data by the second thermometer 33. In that case, the first thermometer 31 can be omitted.

[0019] Also, in this embodiment, the tank temperature acquisition device 29 estimates the temperature inside the filled tank 5 by thermodynamic calculation from the temperature of the supply gas measured by the first thermometer 31 and the pressure value measured by a tank pressure measurement device 37 that measures the pressure of the filled tank.

[0020] The hydrogen gas supply system 1 in this embodiment includes a generator 41 driven by the power of the expander 15. Specifically, the generator 41 is connected to the piston of the expander 15, and the piston is driven by the expansion force of the hydrogen gas H flowing into the expander 15, and the generator 41 is driven by the movement of this piston.

[0021] The hydrogen gas supply system 1 further includes a power storage device 43 for storing the electricity generated by the generator 41. In this example, a rechargeable secondary battery is used as the power storage device 43. However, the power storage device 43 is not limited to a secondary battery, as long as it is a device capable of storing electricity, it may also be a capacitor, for example.

[0022] In the illustrated example, the hydrogen gas supply system 1 includes a compressor 45 that compresses the hydrogen gas H stored in the supply source tank 3 to a predetermined pressure. In this example, a reciprocating compressor 45 is used. An electric motor 47 is connected to the piston of the reciprocating compressor 45. The electric motor 47 is driven by electricity stored in the energy storage device 43, and this electric motor 47 drives the compressor 45. Note that the type of compressor 45 is not limited to a reciprocating type.

[0023] In this embodiment, hydrogen gas H is produced in a manufacturing facility separate from the hydrogen gas supply system 1, and then transported to the hydrogen gas supply system 1 in a transport storage container such as a hydrogen cradle. The transport storage container is introduced into a compressor 45, which pressurizes the hydrogen gas H to a predetermined initial storage pressure in the supply source tank 3, which in this example is 82 MPa. The supply source tank 3 is then filled with this pressurized hydrogen gas H.

[0024] In addition, the configuration for recovering energy from the power of the expander 15 and the configuration for filling the supply source tank 3 with hydrogen gas H described herein may include other necessary devices and equipment not shown in the figures. For example, a suitable transformer, such as a DC-DC converter, may be provided between the energy storage device 43 and the generator 41 and / or electric motor 47. A heat exchanger may be provided between the compressor 45 and the supply source tank 3 to adjust the temperature of the hydrogen gas H introduced into the supply source tank 3. Furthermore, the configuration for recovering energy from the power of the expander 15 and the configuration for filling the supply source tank 3 with hydrogen gas H are not limited to the examples described above, and all or part of the generator 41, energy storage device 43, and compressor 45 may be omitted.

[0025] A flow control valve 51 is provided at the branching point 17 in the supply passage 11. The flow control valve 51 adjusts the flow rate of hydrogen gas H flowing through the branch passage 13. An example of how the flow rate is adjusted by the flow control valve 51 will be described below.

[0026] In the following explanation, "increasing" the flow rate of hydrogen gas H in each passage includes the case where the entire amount of hydrogen gas H flows through that passage and no hydrogen gas H flows through the other passage. Similarly, "decreasing" the flow rate of hydrogen gas H in each passage includes the case where no hydrogen gas H flows through that passage and the entire amount of hydrogen gas H flows through the other passage. Furthermore, in relation to the operation of the flow control valve 51, for the sake of explanation, the state in which the flow control valve 51 is completely closed represents the state in which the entire amount of hydrogen gas H flows through the main passage 12. As the flow control valve 51 is opened from this state, the flow rate of hydrogen gas H flowing through the main passage 12 decreases, while the flow rate of hydrogen gas H flowing through the branch passage 13 increases. The flow control valve 51 is set so that when the flow control valve 51 is completely open, the entire amount of hydrogen gas H flows through the branch passage 13. However, the relationship between the opening and closing operation of the flow control valve 51 and the increase or decrease in the flow rates of both passages may be reversed from this example. Furthermore, the flow control valve 51 may be a valve capable of continuously increasing or decreasing the flow rates in both passages, or it may be a valve capable of directing the entire amount of hydrogen gas H into only one of the passages. In the following description, operating the flow control valve 51 in the opening direction will be simply referred to as "opening," and operating it in the closing direction will be simply referred to as "closing."

[0027] As previously described, the adiabatic compression during supply can cause the temperature of the hydrogen gas H to rise, potentially reducing the tank's lifespan. To avoid this, in this embodiment, the hydrogen gas H supplied to the tank to be filled 5 is pre-cooled. However, if the temperature of the hydrogen gas H supplied to the tank to be filled 5 is excessively low, the tank to be filled 5, which is normally at room temperature, may be excessively cooled and suffer thermal shock. Therefore, it is necessary to mitigate such thermal shock. In this embodiment, a supply gas temperature threshold Ts is set as an indicator value for adjusting the temperature of the supplied hydrogen gas H. The supply gas temperature threshold Ts is, for example, -40°C.

[0028] On the other hand, in this embodiment, the temperature of the supplied hydrogen gas H is controlled considering the heat resistance temperature of the tank to be filled 5. The value that serves as an indicator for this control is called the tank temperature threshold Tt. The heat resistance temperature of the tank to be filled 5 may vary depending on its material. For example, if the material of the tank to be filled 5 is fiber-reinforced plastic, which is advantageous for weight reduction, the heat resistance temperature is 85°C. The tank temperature threshold Tt is set to a value lower than the heat resistance temperature, for example, within the range of 30°C to 75°C. As will be described later, the tank temperature threshold Tt is set as a value that can change depending on the degree of filling of the tank to be filled 5.

[0029] First, let's explain the case where hydrogen gas is supplied from a state where the supply source tank 3 is nearly 100% full. At the start of hydrogen gas supply, the flow control valve 51 is completely closed. In this state, as shown in Figure 3A, if the temperature T1 measured by the first temperature measuring instrument 31 is lower than the supply gas temperature threshold Ts of the hydrogen gas H supplied to the tank to be filled 5, the flow control valve 51 opens in this example, increasing the flow rate of hydrogen gas H passing through the branch passage 13. As the extremely low temperature hydrogen gas H passes through the heat accumulator 19 on the branch passage 13, cold energy is stored in the heat accumulator 19. At the same time, hydrogen gas H at or above the supply gas temperature threshold Ts is supplied to the tank to be filled 5. For example, if supply is started from a state where the tank to be filled 5 is nearly empty, the supply gas temperature will be around -200°C, so the flow control valve 51 is opened.

[0030] As hydrogen gas H is supplied to the tank to be filled 5, the pressure in the supply source tank 3 decreases and the pressure in the tank to be filled 5 increases, reducing the pressure difference between the two tanks 3 and 5. As a result, the degree of temperature decrease of the hydrogen gas H by the expander 15 decreases. In addition, a temperature increase occurs within the tank to be filled 5 due to the compression of the supplied hydrogen gas H. Subsequently, when the temperature T2 acquired by the tank temperature acquisition device 29 exceeds the tank temperature threshold Tt, the flow rate control valve 51 is closed, as shown in Figure 3B, to reduce the flow rate of hydrogen gas H passing through the branch passage 13 and increase the flow rate of hydrogen gas H passing through the main passage 12. This increases the proportion of hydrogen gas H that does not pass through the heat accumulator 19, thus lowering the temperature of the hydrogen gas H supplied to the tank to be filled 5. In this way, the temperature of the hydrogen gas H supplied to the tank to be filled 5 is adjusted to be below the heat resistance temperature of the tank to be filled 5. The tank temperature threshold here is called the first tank temperature threshold Tt1.

[0031] If the supply of hydrogen gas H continues from this state, the pressure difference between the two tanks 3 and 5 will decrease further, thereby further reducing the degree of temperature drop of the hydrogen gas H exiting the expander 15. In this way, when the temperature T2 acquired by the tank temperature acquisition device 29 exceeds the tank temperature threshold Tt, the flow rate of hydrogen gas H passing through the branch passage 13 is increased by the flow rate control valve 51, as shown in Figure 3C. At this time, the hydrogen gas H flowing through the branch passage 13 passes through the heat accumulator 19 and is cooled by the cold energy stored in the heat accumulator 19. As a result, the temperature of the hydrogen gas H supplied to the tank to be filled 5 decreases. In this way, the temperature of the hydrogen gas H supplied to the tank to be filled 5 is adjusted to be below the heat resistance temperature of the tank to be filled 5. The tank temperature threshold here is called the second tank temperature threshold Tt2.

[0032] If the supply of hydrogen gas H continues from this state, the pressure difference between the two tanks 3 and 5 will decrease further, causing the temperature of the hydrogen gas H exiting the expander 15 to rise further. As a result, when the temperature T2 acquired by the tank temperature acquisition device 29 reaches the tank temperature threshold Tt again, the flow control valve 51 is completely closed, and the entire amount of hydrogen gas H flows into the main passage 12. In this case, it is not necessary to adjust the flow rate using the flow control valve 51, or the flow control valve 51 may be completely opened, allowing the entire amount of hydrogen gas H to flow into the branch passage 13. However, at the stage when it is no longer possible to adjust the temperature using the heat accumulator 19, it is preferable to flow the entire amount of hydrogen gas H into the main passage 12 in order to avoid pressure loss due to passing through the heat accumulator 19. The tank temperature threshold here is called the third tank temperature threshold Tt3.

[0033] Furthermore, as the supply of hydrogen gas H increases, the compression ratio within the filled tank 5 decreases and the heat capacity of the filled hydrogen gas increases, so the degree of temperature rise decreases. As a result, as the supply of hydrogen gas H increases, it becomes possible to set a smaller margin for the heat resistance temperature as the tank temperature threshold. Therefore, in the above example, the first to third tank temperature thresholds can be set as Tt1 ≤ Tt2 ≤ Tt3, for example.

[0034] It should be noted that the tank to be filled 5 is not always nearly empty at the start of hydrogen gas supply, and the pressure in the supply source tank 3 may also be low. In other words, the pressure difference between the supply source tank 3 and the tank to be filled 5 at the start of hydrogen gas supply may not be as large as in the example described above, and as a result, the temperature of the hydrogen gas H exiting the expander 15 may be higher than in the example described above, and may exceed the supply gas temperature threshold Ts. In that case, the flow control valve 51 is completely closed until the supply is finished, and the entire amount of hydrogen gas H is allowed to flow through the main passage 12.

[0035] In this example, a first temperature measuring instrument 31 is provided downstream of the confluence point 35 in the supply passage 11, and a second temperature measuring instrument 33 is provided upstream of the branching point 17. However, if the temperature of the hydrogen gas H discharged from the expander 15 can be measured substantially downstream of the confluence point 35 in the supply passage 11, the first temperature measuring instrument 31 may also be used as the second temperature measuring instrument 33, and the temperature measuring instrument upstream of the branching point 17 may be omitted. Specifically, if the entire amount of hydrogen gas H is set to pass through the main passage 12 at the timing when the measured temperature of the hydrogen gas H discharged from the expander 15 is used, then the first temperature measuring instrument 31, which also serves as the second temperature measuring instrument 33, can be provided only downstream of the confluence point 35 in the supply passage 11.

[0036] Furthermore, while such flow rate adjustment is primarily based on monitoring the temperature of hydrogen gas H, as described above, measuring instruments for monitoring pressure and flow rate may be provided at appropriate locations as a supplement. For example, as shown in Figure 1, a first pressure measuring instrument 61 may be provided between the supply source tank 3 and the expander 15, and a second pressure measuring instrument 62 may be provided downstream of the confluence point 35 of the supply passage 11.

[0037] These various measuring instruments and acquisition devices may appropriately include a sensor element for detecting the physical quantity to be measured, various circuits for performing necessary processing such as signal conversion and calculation on the acquired detected quantity, a memory for storing the information necessary for these processes, a power supply element such as a battery or a power supply circuit for receiving power from an external source, and a transmission circuit for transmitting the output signal to the outside by wire or wireless.

[0038] Although not shown in the diagram, a dispenser equipped with a supply nozzle to the tank to be filled 5 is provided at the downstream end of the supply passage 11. Some of the various measuring instruments mentioned above may be housed inside the dispenser.

[0039] Furthermore, in order to maintain the supply pressure to the tank being filled, the supply pressure at the second pressure gauge 62, that is, the discharge pressure from the supply nozzle described above, may be controlled. Specifically, for example, the hydrogen gas supply system 1 may receive pressure information inside the tank being filled 5 measured by the tank pressure gauge 37, and control the supply pressure at the second pressure gauge 62 so that it is approximately 1.2 to 1.3 times the pressure inside the tank being filled 5. Alternatively, the supply pressure at the second pressure gauge 62 may be controlled so that it is approximately 1.2 to 1.3 times the assumed pressure when the tank being filled 5 is 100% filled with hydrogen gas H, for example, 70 MPa. Such control of the hydrogen gas H supply pressure can be achieved, for example, by controlling the discharge flow rate from the expander 15, that is, the rotational speed (rpm) of the expander 15.

[0040] In the above embodiment, an example was shown in which only one supply source tank 3 is installed, but the hydrogen gas supply system 1 may be equipped with multiple supply source tanks 3.

[0041] For example, as shown in Figure 4 as one modified example, the hydrogen gas supply system 1 may include a sub-source tank 55. The sub-source tank 55 is connected to the upstream portion of the expander 15 in the supply passage 11 via a connecting passage 57. An on-off valve 59 is provided in the connecting passage 57. In this modified hydrogen gas supply system 1, if the hydrogen gas H in the source tank 3, which was the initial source, decreases and the pressure drops, the on-off valve 59 can be opened to supply hydrogen gas from the sub-source tank 55. This makes it possible to suppress the temperature rise of the hydrogen gas H caused by the decrease in the pressure difference between the source tank 3 and the tank being filled 5. In this modified example, the hydrogen gas H from the sub-source tank 55 is also configured to pass through the expander 15. Therefore, the temperature of the hydrogen gas H can be adjusted by operating the flow rate switching valve 51 in the same way as described above.

[0042] Furthermore, as shown in Figure 5 as another modified example, the hydrogen gas supply system 1 includes two sets of supply source tanks 3 capable of handling multiple, in this example, two, filled tanks 5, supply passages 11, branch passages 13, expander 15, heat accumulator 19, flow control valve 51, first temperature measuring instrument 31, and tank temperature acquisition device 29, etc. Here, the set of these components for supplying hydrogen gas H to one filled tank 5 is called a "supply system set S". The two supply passages 11 of the two supply system sets S are connected by a connecting passage 61 upstream of the branching point 17. A flow path switching valve 63 is provided at the connection point between the two supply passages 11 and the connecting passage 61. These connecting passage 61 and the two flow path switching valves 63 constitute a supply source switching mechanism 65 that switches between supply source tanks 3 communicating with multiple supply passages 11.

[0043] According to this modified hydrogen gas supply system 1, by having multiple supply system groups S, hydrogen gas H can be supplied to multiple tanks 5 to be filled simultaneously. Furthermore, if only one of the supply system groups S is operating and the hydrogen gas H in the supply source tank 3 of that supply system group S decreases and the pressure drops, the supply source can be switched to the supply source tank 3 of another supply system group S by operating the supply source switching mechanism 65. In this modified version, hydrogen gas H from the supply source tanks 3 of other supply system groups S is also configured to pass through the expander 15. Therefore, the temperature adjustment of hydrogen gas H by operating the flow rate switching valve 51 can be performed in the same way as described above. Note that the configuration of the connecting passages and / or valves constituting the supply source switching mechanism 65 is not limited to the illustrated example. Also, unlike the illustrated example, the connecting passages may be provided to connect the upstream portions of the expanders 15 in each supply passage 11.

[0044] Although not shown in Figure 5, each supply system group S includes, as appropriate, the generator 41, energy storage device 43, compressor 45, etc., in addition to the components described above, as well as those described in Figure 1.

[0045] Furthermore, the hydrogen gas supply system 1 according to this embodiment may be configured as a mobile system that can be moved by mounting the above-described supply system assembly S on a vehicle. When using a refrigerator as in the conventional method, in addition to the large size of the refrigerator itself, auxiliary equipment such as a power generator to drive it may also be required, resulting in a large overall system. In contrast, the hydrogen gas supply system 1 according to this embodiment uses an expander 15 to cool the hydrogen gas H, so the entire system can be made small and lightweight and mounted on a mobile vehicle. By making the hydrogen gas supply system 1 a mobile system in this way, it becomes possible to supply hydrogen gas even in areas where it is difficult to permanently install the hydrogen supply system 1.

[0046] In the above embodiment, an example was described in which the tank to be filled 5 is the fuel tank of a fuel cell vehicle 7. However, the use of the tank to be filled 5 is not limited as long as it is a tank that is filled by pressurized hydrogen gas H.

[0047] As described above, the hydrogen gas supply system 1 according to the first aspect of this disclosure is A system for supplying compressed hydrogen gas H from a source tank 3 that stores compressed hydrogen gas H to a tank to be filled 5 that is at a lower pressure than the source tank 3, The aforementioned supply source tank 3, A supply passage 11 for passing hydrogen gas H from the supply source tank 3 to the tank to be filled 5, the supply passage having a main passage 12 and a branch passage 13 that branch off and merge with each other along the way, An expander 15 is provided in the supply passage 11 in the portion upstream of the branching point 17 of the branching passage 13, for expanding the hydrogen gas H, A heat storage device 19 is provided in the branch passage 13 to store the cold energy of the hydrogen gas H, A flow control valve 51 is provided at the branching point 17 in the supply passage 11 to adjust the flow rate of hydrogen gas H in the branch passage 13, A supply gas temperature acquisition device 27 acquires the temperature of the hydrogen gas H supplied to the tank 5 to be filled, A tank temperature acquisition device 29 that acquires the temperature inside the filled tank 5, It is equipped with.

[0048] This configuration uses an expander 15 to cool the hydrogen gas H, enabling significantly lower operating costs and miniaturization compared to conventional systems using a refrigerator. Furthermore, by using the expander 15 and a heat accumulator 19 together, the thermal shock to the filled tank 5 caused by supplying excessively low-temperature hydrogen gas H can be mitigated. In addition, the heat accumulator 19 allows for temperature control of the hydrogen gas H, further improving the overall efficiency of the system.

[0049] A hydrogen gas supply system 1 according to a second aspect of this disclosure comprises, in the hydrogen gas supply system 1 according to the first aspect, a generator 41 driven by power recovered as expansion energy of the hydrogen gas H by the expander 15, and a power storage device 43 for storing the electricity generated by the generator 41. With this configuration, the energy recovered by the expander 15 can be converted into electrical energy to drive other devices in the system. Therefore, the overall efficiency of the system can be improved.

[0050] A third aspect of the present disclosure of the hydrogen gas supply system 1 is a hydrogen gas supply system 1 according to the first or second aspect of the present disclosure in which the expander 15 is a reciprocating expander. With this configuration, a desired expansion ratio can be obtained in a compact size.

[0051] A hydrogen gas supply system 1 according to a fourth aspect of this disclosure is a hydrogen gas supply system 1 according to any of the first to third aspects, further comprising a sub-supply source tank 55 connected to the upstream portion of the supply passage 11 of the expander 15, and an on-off valve 59 provided in the connection passage 57 of the sub-supply source tank 55. With this configuration, if the hydrogen gas H in the supply source tank 3, which was the supply source at the start of supply, decreases and the pressure drops, the supply source can be switched to the sub-supply source tank 55 by operating the flow path switching valve. This makes it possible to suppress the temperature rise of the hydrogen gas H caused by the decrease in the pressure difference between the supply source tank 3 and the tank to be filled 5.

[0052] A hydrogen gas supply system 1 according to the fifth aspect of this disclosure is a hydrogen gas supply system 1 according to any of the first to third aspects, Multiple sets of the supply source tanks 3, the supply passage 11, the branch passage 13, the expander 15, the heat storage unit 19, the flow rate control valve 51, the supply gas temperature acquisition device 27, and the tank temperature acquisition device 29, A connecting passage connects the multiple supply passages 11 at the upstream portion of the branching point 17, The system includes a flow path switching valve provided in the aforementioned connecting passage. With this configuration, by having multiple supply system sets S, hydrogen gas H can be supplied to multiple tanks 5 to be filled simultaneously. Furthermore, if only one of the supply system sets S is operating and the hydrogen gas H in the supply source tank 3 of that supply system set S decreases and the pressure drops, the supply source can be switched to the supply source tank 3 of another supply system set S by operating the flow path switching valve.

[0053] The hydrogen gas supply system 1 according to the sixth aspect of this disclosure is a hydrogen gas supply system 1 according to any of the first to fifth aspects, further comprising: The hydrogen gas supply system 1 according to this disclosure uses an expander 15 instead of a conventional refrigerator to cool the hydrogen gas H, so the entire system can be made small and lightweight and mounted on a mobile vehicle.

[0054] The method for operating the hydrogen gas supply system 1 according to the first aspect of this disclosure is a method for operating the system according to any of the first to sixth aspects, When the temperature T1 obtained by the supply gas temperature acquisition device 27 is lower than the supply gas temperature threshold Ts of the hydrogen gas H supplied to the tank to be filled 5, the flow rate of the hydrogen gas H passing through the branch passage 13 is increased by the flow rate control valve 51 to store cold energy in the heat storage device 19. After storing cold energy in the heat storage device 19, if the temperature T2 obtained by the tank temperature acquisition device 29 exceeds the tank temperature threshold Tt, the flow rate of hydrogen gas H passing through the branch passage 51 is reduced by the flow rate control valve 51 to adjust the temperature T2 obtained by the tank temperature acquisition device 29 to be below the tank temperature threshold Tt. The system includes, after storing cold energy in the heat storage unit 19, if the temperature T2 obtained by the tank temperature acquisition device 29 exceeds the tank temperature threshold Tt, increasing the flow rate of hydrogen gas H passing through the branch passage 51 using the flow rate control valve 51 to adjust the temperature T2 obtained by the tank temperature acquisition device 29 to be below the tank temperature threshold Tt.

[0055] With this configuration, by using the expander 15 and the heat accumulator 19 together, the thermal shock to the tank being filled 5 caused by supplying an excess of low-temperature hydrogen gas H can be mitigated. Furthermore, since the temperature of the hydrogen gas H can be adjusted using the heat accumulator 19, the overall efficiency of the system is improved.

[0056] As described above, preferred embodiments of the present disclosure have been explained with reference to the drawings, but various additions, modifications, or deletions are possible without departing from the spirit of the present disclosure. Accordingly, such additions, modifications, or deletions are also included within the scope of the present disclosure. [Explanation of Symbols]

[0057] 1. Hydrogen gas supply system 3. Supply source tank 5. Tank to be filled 7 Water electrolysis equipment 11 Supply passage 12 Main aisle 13 Branching passage 15 Inflator 17 Branching Point 19 Heat storage 27. Supply gas temperature acquisition device 29 Tank temperature acquisition device 31. First temperature measuring instrument 33. Second temperature measuring instrument 41 Generator 43 Energy storage device 51 Flow control valve H Hydrogen gas

Claims

1. A system for supplying hydrogen gas from a source tank that stores compressed hydrogen gas to a tank to be filled, which is at a lower pressure than the source tank, The aforementioned supply source tank, A supply passage for passing hydrogen gas from the supply source tank to the tank to be filled, comprising a main passage and branch passages that branch off and merge with each other along the way, An expander for expanding the hydrogen gas is provided in the supply passage, in the portion upstream of the branching point of the branch passage, A heat storage device is provided in the aforementioned branch passage for storing the cold energy of the hydrogen gas, A flow control valve is provided at the branching point in the supply passage to adjust the flow rate of hydrogen gas in the branch passage, A supply gas temperature acquisition device that acquires the temperature of the hydrogen gas supplied to the tank to be filled, A tank temperature acquisition device that acquires the temperature inside the tank to be filled, Equipped with, Hydrogen gas supply system.

2. In the hydrogen gas supply system according to claim 1, A generator driven by power recovered as expansion energy of the hydrogen gas by the aforementioned expander, A power storage device for storing the electricity generated by the aforementioned generator, A hydrogen gas supply system equipped with the following features.

3. In the hydrogen gas supply system according to claim 1 or 2, The aforementioned expander is a reciprocating expander. Hydrogen gas supply system.

4. In the hydrogen gas supply system according to claim 1 or 2, further, A sub-supply source tank connected to the upstream portion of the expansion machine in the supply passage, A hydrogen gas supply system comprising an on / off valve provided in the connection passage of the sub-supply tank.

5. In the hydrogen gas supply system according to claim 1 or 2, Multiple sets of the supply source tanks, the supply passage, the branch passage, the expander, the heat storage unit, the flow rate control valve, the supply gas temperature acquisition device, and the tank temperature acquisition device, A supply source switching mechanism that switches between the supply source tanks communicating with multiple supply passages, A hydrogen gas supply system equipped with the following features.

6. In the hydrogen gas supply system according to claim 1 or 2, further, A hydrogen gas supply system comprising the supply source tank, the supply passage, the branch passage, the expander, the heat storage unit, the flow rate control valve, the supply gas temperature acquisition device, and a vehicle that moves while carrying the tank temperature acquisition device.

7. A method for operating the hydrogen gas supply system according to claim 1 or 2, When the temperature obtained by the supply gas temperature acquisition device is lower than the supply gas temperature threshold of the hydrogen gas supplied to the tank to be filled, the flow rate of the hydrogen gas passing through the branch passage is increased by the flow rate control valve to store cold energy in the heat storage device. After storing cold energy in the heat storage device, if the temperature obtained by the tank temperature acquisition device exceeds the tank temperature threshold, the flow rate of hydrogen gas passing through the branch passage is reduced by the flow rate control valve to adjust the temperature obtained by the tank temperature acquisition device to be below the tank temperature threshold. After storing cold energy in the heat storage device, if the temperature obtained by the tank temperature acquisition device exceeds the tank temperature threshold, the flow rate of hydrogen gas passing through the branch passage is increased by the flow rate control valve to adjust the temperature obtained by the tank temperature acquisition device to be below the tank temperature threshold. A method for operating a hydrogen gas supply system, including the operation of the hydrogen gas supply system.

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