Hydrogen station and hydrogen station operation method

Abstract

To provide a hydrogen station capable of storing hydrogen remaining in a vaporization unit as low-pressure hydrogen without discarding it, and also capable of reducing pressure in the vaporization unit.SOLUTION: A hydrogen station comprises a liquid hydrogen tank, a vaporization unit, a pressure sensor, a high-pressure accumulation container, a surge tank, a low-pressure accumulation container, a dispenser, and a control unit. The control unit employs means for closing a flow path to the high-pressure accumulation container and opening the flow path to the surge tank when the pressure sensor detects a first pressure value, and for closing the flow path to the surge tank and opening the flow path to the low-pressure accumulator container when the pressure sensor detects a second pressure value or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a hydrogen station that fills hydrogen vaporized in a vaporization unit into a high-pressure accumulator vessel and a low-pressure accumulator vessel according to the pressure value of the hydrogen. [Background technology]

[0002] In recent years, efforts to move towards a decarbonized society have been progressing with the development of technologies that use hydrogen as an energy source. Among these, in the transportation sector, including automobiles, development of hydrogen vehicles that run on hydrogen is ongoing. At hydrogen stations that handle hydrogen to be filled into hydrogen vehicles, methods of vaporizing liquid hydrogen and filling it into a pressure accumulator include using a high-performance compressor to increase the pressure of the hydrogen vaporized in a vaporizer and filling it into a high-pressure accumulator, and also using a method in which the inside of the vaporizer is sealed off to increase the pressure to a high level and then the hydrogen is filled directly into a high-pressure accumulator. However, in the method of sealing the inside of the vaporizer, the pressure inside the vaporizer must be reduced to below the pressure of the liquid hydrogen tank after filling the high-pressure accumulator vessel in order for the liquid hydrogen to vaporize. Therefore, the low-pressure hydrogen remaining in the vaporizer is released into the atmosphere to reduce the pressure, which poses the problem of wasting a large amount of hydrogen each time the accumulator vessel is filled.

[0003] To solve the above problems, a technology has been proposed in Japanese Patent No. 5759741 (Patent Document 1). Specifically, the proposed technology involves splitting the vaporized hydrogen midway through a heat exchanger that vaporizes liquid hydrogen, and then combining the room-temperature hydrogen that has passed through the heat exchanger with the low-temperature hydrogen, thereby filling vehicles with temperature-adjusted hydrogen.

[0004] However, in the technical proposal described in Patent Document 1, since a pressure accumulator vessel is not provided on the hydrogen gas supply route after the vehicle is filled with hydrogen, there is a problem in that excess vaporized hydrogen remaining in the heat exchanger and piping must be disposed of externally.

[0005] The applicant came up with the idea that it might be possible to efficiently recover and utilize the low-pressure hydrogen that is generated after filling the high-pressure accumulator vessel in the hydrogen stations described above, and focused on technology for storing hydrogen using a surge tank.He developed a hydrogen station that opens a flow path to the surge tank after filling the high-pressure accumulator vessel from the vaporization unit, and stores the remaining hydrogen in the vaporization unit as low-pressure hydrogen in the surge tank, while reducing the pressure in the vaporization unit to below the pressure of the liquid hydrogen tank, which has led to the proposal of the ``hydrogen station and hydrogen station operating method'' of the present invention. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5759741 Summary of the Invention [Problem to be solved by the invention]

[0007] In view of the above problems, the present invention aims to provide a hydrogen station that can store hydrogen remaining in the vaporization unit as low-pressure hydrogen without discarding it, and that can reduce the pressure within the vaporization unit. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides a vaporization unit that vaporizes liquid hydrogen flowing from a liquid hydrogen tank, and a hydrogen pressure reducing device in the vaporization unit. value a pressure sensor that detects the pressure of the vaporized hydrogen in the vaporization unit; a high-pressure accumulator vessel that stores the high-pressure hydrogen vaporized in the vaporization unit; After filling the high-pressure accumulator vessel low pressure Remaining A surge tank that stores hydrogen and low-pressure gas sent from the surge tank RemainingThe hydrogen vehicle is equipped with a low-pressure accumulator vessel for storing hydrogen, a dispenser for supplying hydrogen stored in the high-pressure accumulator vessel or the low-pressure accumulator vessel to a hydrogen tank of the hydrogen vehicle, and a control unit, the control unit determining a first pressure value based on the detection result of the pressure sensor. rose to time, From the vaporization unit The flow path to the high-pressure accumulator vessel is closed, and From the vaporization unit Open the flow path to the surge tank and the second pressure value is detected by the pressure sensor. It descended to time, From the vaporization unit Close the flow path to the surge tank, From the vaporization unit Means are provided for opening a flow path to a low pressure accumulator vessel.

[0009] Furthermore, the present invention employs a means in which the low-pressure pipe disposed between the vaporization unit and the surge tank has a larger pipe diameter than the high-pressure pipe disposed between the vaporization unit and the high-pressure accumulator vessel.

[0010] Furthermore, the present invention is provided with a pressure adjustment unit upstream of the surge tank, and the control unit employs means for closing the flow path to the high-pressure accumulator vessel and opening the flow path to the pressure adjustment unit when filling of the high-pressure accumulator vessel is completed.

[0011] Furthermore, the present invention employs a means in which a compressor is provided in the subsequent stage of the surge tank.

[0012] Furthermore, the present invention takes the measure of providing cooling means for cooling the vaporization unit.

[0013] Furthermore, the present invention employs a means for providing a heating means for heating the vaporization unit.

[0014] Furthermore, the present invention has a pressure sensor A that detects the pressure inside the hydrogen tank of a hydrogen vehicle and a pressure sensor B that detects the pressure in a low-pressure accumulator vessel, and the control unit employs a means for opening the flow path of the low-pressure accumulator vessel when the pressure value of pressure sensor A is lower than the pressure value of pressure sensor B based on the detection results of pressure sensor A and pressure sensor B.

[0015] Furthermore, the present invention provides a method for storing liquid hydrogen in a liquid hydrogen tank, a method for vaporizing the liquid hydrogen flowing from the liquid hydrogen tank in a vaporization unit, and a method for measuring the hydrogen pressure in the vaporization unit by a pressure sensor. value a step of detecting the presence of hydrogen in the gas, a step of storing the high-pressure hydrogen vaporized in the vaporization unit in a high-pressure accumulator vessel, and a step of storing the high-pressure hydrogen vaporized in the vaporization unit in a surge tank. After filling the high-pressure accumulator vessel low pressure Remaining A process for storing hydrogen and a process for storing low-pressure hydrogen sent from a surge tank to a low-pressure storage vessel. Remaining a step of storing hydrogen; a step of supplying hydrogen stored in a high-pressure accumulator vessel or a low-pressure accumulator vessel from a dispenser to a hydrogen tank of a hydrogen vehicle; and a step of detecting a first pressure value based on the detection result of the pressure sensor in a control unit. rose to time, From the vaporization unit The flow path to the high-pressure accumulator vessel is closed, and From the vaporization unit a step of opening a flow path to a flow path to a surge tank; and a step of detecting a second pressure value based on the detection result of the pressure sensor in a control unit. It descended to time, From the vaporization unit Close the flow path to the surge tank, From the vaporization unit and opening a flow path to the low-pressure accumulator vessel. [Effects of the Invention]

[0016] According to the hydrogen station of the present invention, the control unit controls the opening and closing of the flow path based on the detection results of the pressure sensor, thereby achieving the excellent effect of efficiently filling the vaporization unit with hydrogen and adjusting the pressure for vaporization within the vaporization unit.

[0017] In addition, the hydrogen station according to the present invention has an excellent effect in that the low-pressure pipe has a larger pipe diameter than the high-pressure pipe, making it possible to reduce the pressure of the low-pressure hydrogen flowing into the surge tank.

[0018] Furthermore, the hydrogen station according to the present invention has an excellent effect in that a pressure adjustment section is provided upstream of the surge tank, making it possible to introduce low-pressure hydrogen that is adjusted so as not to apply excessive pressure to the surge tank.

[0019] Furthermore, the hydrogen station according to the present invention has an excellent effect in that a compressor is provided downstream of the surge tank, making it possible to increase the hydrogen pressure in the surge tank to a predetermined level and send it to the downstream stage.

[0020] Furthermore, the hydrogen station according to the present invention is provided with a cooling means for cooling the vaporization unit, which has the excellent effect of making it possible to send the hydrogen remaining in the vaporization unit to the surge tank with its temperature and pressure reduced.

[0021] Furthermore, the hydrogen station according to the present invention is provided with a heating means for heating the vaporization unit, which has the excellent effect of increasing the ambient temperature when vaporizing liquid hydrogen, thereby accelerating the vaporization rate and the rate at which the hydrogen pressure increases.

[0022] Furthermore, the hydrogen station according to the present invention has an excellent effect in that it has a pressure sensor that detects the pressure inside the hydrogen tank of a hydrogen vehicle and the pressure inside the low-pressure accumulator vessel, making it possible to preferentially fill the hydrogen inside the low-pressure accumulator vessel into the hydrogen tank. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is an explanatory diagram showing an embodiment of a hydrogen station according to the present invention; [Figure 2] 1 is an explanatory diagram showing an embodiment of a vaporization unit of a hydrogen station according to the present invention; [Figure 3] 4 is a pressure timing chart when filling a pressure accumulator vessel of the hydrogen station according to the present invention. [Figure 4] 4 is a pressure timing chart when filling a hydrogen tank of the hydrogen station according to the present invention. [Figure 5] 4 is a flowchart showing the process of filling a pressure accumulator vessel at a hydrogen station according to the present invention. [Figure 6] 4 is a flowchart showing the process of filling a hydrogen tank at a hydrogen station according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] The greatest feature of hydrogen gas station 1 according to the present invention is that low-pressure hydrogen remaining in vaporization unit 10 is stored in surge tank 30, thereby reducing the pressure inside vaporization unit 10. Hereinafter, an embodiment of a hydrogen gas station 1 according to the present invention will be described with reference to the drawings.

[0025] Furthermore, the hydrogen gas station 1 of the present invention is not particularly limited to the embodiments described below, and can be modified as appropriate within the scope of the technical concept of the present invention, i.e., within the scope of shapes, dimensions, materials, etc. that can achieve the same functional effects.

[0026] FIG. 1 is an explanatory diagram showing an embodiment of a hydrogen gas station 1 according to the present invention, in which pressure sensors provided in each part are indicated as P and control points of a control unit are indicated as C on the drawing. FIG. 2 is an explanatory diagram showing the operation of the vaporization unit of the hydrogen gas station 1 according to the present invention. FIG. 3 is a pressure timing chart when the pressure accumulator vessel is filled. FIG. 4 is a pressure timing chart when filling the hydrogen tank of the hydrogen gas station 1 according to the present invention. FIG. 5 is a flowchart showing the process of filling the pressure accumulator container at the hydrogen gas station 1 according to the present invention. FIG. 6 is a flowchart showing the process of filling the hydrogen tank at the hydrogen gas station 1 according to the present invention. The hydrogen gas station 1 of the present invention is composed of a liquid hydrogen tank 2, a vaporization unit 10, a high-pressure accumulator vessel 20, a surge tank 30, a low-pressure accumulator vessel 31, a dispenser 40 (hereinafter sometimes referred to as "each part"), and a control unit 50.

[0027] As shown in Figure 1, each part is connected with a pipe capable of delivering high-pressure hydrogen. There are no particular limitations on the material or configuration of the pipe used to connect each part, as long as it is made using conventionally known technology. Furthermore, inlet pipe 4 disposed between liquid hydrogen tank 2 and vaporization unit 10 is a pipe capable of transporting liquid hydrogen.

[0028] Each part is provided with a pressure sensor capable of measuring a pressure value. In FIG. 1, the pressure sensor is indicated as P. The pressure sensor A is provided in the dispenser 40 and measures the pressure value inside the hydrogen tank 46 . The pressure sensor B is provided in the low-pressure accumulator vessel 31 and measures the pressure value inside the low-pressure accumulator vessel 31. The pressure sensor D is provided in the high-pressure accumulator vessel 20 and measures the pressure value inside the high-pressure accumulator vessel 20. The pressure sensor E is provided in the surge tank 30 and measures the pressure value inside the surge tank 30. The pressure sensor F is provided in the vaporization unit 10 and measures the pressure value inside the vaporization unit 10 . The pressure sensor G is provided in the liquid hydrogen tank 2 and measures the pressure value inside the liquid hydrogen tank 2. The measurement data measured by each pressure sensor is transmitted to the control unit 50. Furthermore, pressure sensors for measuring pressure are also installed in the pipes connecting the various parts as required.

[0029] The liquid hydrogen tank 2 is a tank for storing liquid hydrogen transported from a tank truck or the like. Liquid hydrogen tank 2 is connected to vaporization unit 10 via inlet pipe 4 having inlet valve 3 , and delivers liquid hydrogen to vaporization unit 10 . The structure of the liquid hydrogen tank 2 may be any known technology capable of maintaining the temperature of the stored liquid hydrogen (-253°C). The capacity of the liquid hydrogen tank 2 is determined taking into consideration the size of the hydrogen gas station 1, the capacity of the pressure accumulator vessel, the filling frequency, etc. In addition, inlet valve 3 provided on inlet pipe 4 is a valve that allows liquid hydrogen stored in liquid hydrogen tank 2 to flow into vaporization unit 10, and is opened and closed when vaporization is performed in vaporization unit 10. At this time, by immediately closing inlet valve 3 after the liquid hydrogen required for vaporization has been delivered, it is possible to prevent hydrogen vaporized in vaporization unit 10 from flowing back into liquid hydrogen tank 2.

[0030] Before vaporization in vaporization unit 10, liquid hydrogen tank 2 sends a predetermined amount of liquid hydrogen to vaporization unit 10. At this time, the predetermined amount sent to vaporization unit 10 is determined based on the volume of hydrogen that can be filled into high-pressure accumulator vessel 20, the volume of hydrogen produced by vaporizing the liquid hydrogen, etc.

[0031] The vaporization unit 10 is a unit for vaporizing the liquid hydrogen that flows in from the liquid hydrogen tank 2, and is connected to a high-pressure pipe 12 that is connected to the high-pressure accumulator vessel 20 and a low-pressure pipe 13 that is connected to the surge tank 30. The specific structure of vaporization unit 10 is such that liquid hydrogen flowing in from liquid hydrogen tank 2 is vaporized within vaporization unit 10 and then sent toward high-pressure accumulator vessel 20 or surge tank 30. For example, as shown in FIG. 2, liquid hydrogen flowing into piping arranged in a roughly ladder shape is vaporized and sent to high-pressure accumulator vessel 20 via high-pressure pipe 12 or to surge tank 30 via low-pressure pipe 13. By configuring the vaporization unit 10 with a generally ladder-shaped piping structure, it is relatively easy to create a structure that maintains a certain level of strength while increasing the surface area of ​​the piping. The more ladders there are, the greater the surface area can be, which is preferable. Furthermore, the piping used in the vaporization unit 10 naturally has a strength that can withstand the pressure inside the high-pressure accumulator vessel 20 or higher. When vaporizing liquid hydrogen, liquid hydrogen is introduced at the pressure difference between the pressure inside vaporization unit 10 and liquid hydrogen tank 2, so the pressure inside vaporization unit 10 must be set to a pressure value (hereinafter also referred to as the "second pressure value") lower than the pressure inside liquid hydrogen tank 2. For example, if the pressure inside liquid hydrogen tank 2 is between 0.4 MPa and 1 MPa, the second pressure value should be set to 0.4 MPa or less, preferably 0.3 MPa or less.

[0032] The high-pressure accumulator vessel 20 is a pressure accumulator vessel that is filled via a high-pressure pipe 12 with high-pressure hydrogen vaporized in a vaporization unit (hereinafter simply referred to as "high-pressure hydrogen"). The pressure value of the hydrogen stored in the high-pressure accumulator vessel 20 (hereinafter referred to as the "first pressure value") must be at least higher than the pressure value at which hydrogen is filled into the hydrogen tank 46 of a hydrogen vehicle, and for example, if the pressure value at which hydrogen is filled into the hydrogen tank 46 is 70 MPa, it is desirable that the first pressure value be increased to approximately 82 MPa. Furthermore, the specific structure of the high-pressure accumulator vessel 20 may be a structure using conventionally known technology. The storage capacity and number of high-pressure accumulator vessels 20 are determined in consideration of the amount of hydrogen supply required by the hydrogen gas station 1.

[0033] Surge tank 30 is a tank that temporarily stores hydrogen remaining in vaporization unit 10 (hereinafter referred to as “low-pressure hydrogen”) via low-pressure pipe 13 after being filled with high-pressure hydrogen. The surge tank 30 is a tank that temporarily stores the low-pressure hydrogen remaining in the vaporization unit 10 after high-pressure hydrogen has been filled into the high-pressure accumulator vessel 20 via the low-pressure pipe 13, and is a tank that is installed so that the hydrogen can be sent to the downstream low-pressure accumulator vessel 31 at a stable pressure. The pressure in surge tank 30 is set lower than the pressure in vaporization unit 10 in order to allow low-pressure hydrogen to flow into surge tank 30 due to the pressure difference with vaporization unit 10. Furthermore, by setting the pressure in surge tank 30 to a pressure value lower than the second pressure value, it becomes possible to store hydrogen in surge tank 30 and simultaneously reduce the pressure in vaporization unit 10 to the second pressure value. The capacity of surge tank 30 need only be large enough to store the expected amount of low-pressure hydrogen (amount of vaporized hydrogen minus the amount filled into high-pressure accumulator vessel 20). Furthermore, if the pressure value inside vaporization unit 10 is to be kept below a second pressure value by storing hydrogen in surge tank 30, the capacity must take into account the volume expansion that occurs as the pressure of the stored low-pressure hydrogen decreases. For example, if 5 L of low-pressure hydrogen compressed to 80 MPa is to be reduced to 0.4 MPa, the pressure inside surge tank 30, and then stored, the capacity must be large enough to store the volume of low-pressure hydrogen (5 L × 80 MPa) divided by the pressure of surge tank 30 (0.4 MPa), or 1000 L.

[0034] Low-pressure hydrogen has a maximum pressure value equivalent to the first pressure value, and if it were to flow directly into the surge tank 30, there is a possibility that the surge tank 30 would be damaged by that pressure. For this reason, as shown in Figure 2, a pressure adjustment unit 32 is provided upstream of the surge tank 30 to keep the pressure flowing into the surge tank 30 below a certain level (for example, 0.5 MPa). By providing the pressure adjustment unit 32, it is possible to flow low-pressure hydrogen into the surge tank 30 while adjusting it so that excessive pressure is not applied. Furthermore, when hydrogen filling into the high-pressure accumulator vessel 20 is complete, the flow path to the high-pressure accumulator vessel 20 is closed and the flow path to the pressure adjustment unit 32 is opened. The structure of the pressure adjustment unit 32 may be any structure that uses conventionally known technology, and the pressure value adjusted by the pressure adjustment unit 32 is set to a value higher than the pressure inside the surge tank 30, taking into consideration the specifications of the surge tank 30, etc.

[0035] The vaporization unit 10 is connected to a high-pressure pipe 12 that sends high-pressure hydrogen to a high-pressure storage vessel 20 and a low-pressure pipe 13 that sends low-pressure hydrogen to a surge tank 30. By making the diameter of the piping used for the low-pressure pipe 13 larger than that of the high-pressure pipe 12, it is possible to reduce the pressure of the low-pressure hydrogen flowing into the surge tank 30 to at least be lower than the pressure in the high-pressure pipe 12, which helps to reduce the pressure burden on the surge tank 30 and the pressure adjustment unit 32.

[0036] The low-pressure accumulator vessel 31 is a pressure accumulator vessel that stores hydrogen delivered from the surge tank 30 via a low-pressure accumulator pipe 35 and delivers hydrogen to the dispenser 40 . The low-pressure accumulator vessel 31 stores low-pressure hydrogen delivered from the surge tank 30 via the low-pressure accumulator pipe 35, reduces the pressure within the surge tank 30, and delivers the stored hydrogen to a dispenser 40 connected downstream. A container using conventionally known technology may be used for the specific structure of the low-pressure accumulator vessel 31. In addition, the capacity of the low-pressure accumulator vessel 31 is preferably large enough to store an amount of hydrogen equivalent to the amount of hydrogen that can be stored in the surge tank 30, in order to reduce the pressure inside the surge tank 30. Regarding the flow path from the low-pressure accumulator vessel 31 to the dispenser 40, the control unit 50 controls the flow path to be opened and air to be supplied to the dispenser 40 when the pressure in the low-pressure accumulator vessel 31 is greater than that of the hydrogen tank 46, based on the pressure values ​​measured by the pressure sensor A provided in the dispenser 40 and the pressure sensor B provided in the low-pressure accumulator vessel 31.

[0037] A compressor 33 is disposed downstream of the surge tank 30 to draw in and compress the low-pressure hydrogen stored in the surge tank 30 and send it to the low-pressure accumulator vessel 31 . The compression operation of compressor 33 increases the pressure of hydrogen in surge tank 30 to a predetermined level (e.g., 40 MPa) and allows it to be sent to a subsequent stage. In addition, the suction action associated with the compression operation of compressor 33 reduces the pressure in surge tank 30 below the second pressure value, thereby achieving the excellent effect of smoothing the inflow of low-pressure hydrogen from vaporization unit 10.

[0038] As shown in Fig. 1, each pipe used as a hydrogen flow path is provided with a control valve whose opening and closing is controlled by a control unit 50. Specifically, an inlet valve 3 is provided in the inlet pipe 4, a high-pressure delivery valve 14 in the high-pressure pipe 12, a low-pressure delivery valve 15 in the low-pressure pipe 13, and an accumulator valve 34 in the low-pressure accumulator pipe 35, and the opening and closing of each flow path is controlled by the control unit 50. Pressure values ​​measured by pressure sensors (denoted by P in Fig. 1) provided in each of the aforementioned parts are used as the opening and closing criteria for the control valves. Although not shown, each control valve is provided with a check valve to prevent hydrogen from flowing back to the previous stage when the control valve is opened.

[0039] The hydrogen tank 46 is a hydrogen tank mounted on a hydrogen vehicle that uses hydrogen as fuel. The hydrogen tank 46 is filled with hydrogen by connecting to the dispenser 40, and the amount to be filled is determined by the user's specification, with the capacity of the hydrogen tank 46 being the limit.

[0040] The dispenser 40 is a device that is connected to a hydrogen tank 46 and fills the tank with hydrogen up to a specified filling level. The dispenser 40 is a device that, when connected to the hydrogen tank 46, fills the hydrogen supplied from either the high-pressure accumulator vessel 20 or the low-pressure accumulator vessel 31 up to the filling amount specified by the hydrogen tank 46 or the filling amount specified by the user (hereinafter referred to as the "specified filling value"). A pressure sensor A is provided at the connection between the dispenser 40 and the hydrogen tank 46, and by connecting the dispenser 40 and the hydrogen tank 46, the pressure value inside the hydrogen tank 46 is measured and transmitted to the control unit.

[0041] When hydrogen is filled into the hydrogen tank 46 by the dispenser 40, the high-pressure hydrogen increases the pressure inside the tank, causing adiabatic compression and increasing the temperature inside the hydrogen tank 46. For this reason, it is preferable to provide a precooler that pre-cools the hydrogen to be flowed into the hydrogen tank 46 (to about -40°C, for example) beforehand, either before the dispenser 40 or built into the dispenser 40.

[0042] As a method of connecting the dispenser 40 with the high-pressure accumulator vessel 20 and the low-pressure accumulator vessel 31, in addition to a mode in which pipes are directly connected, a mode in which pipes extending from the high-pressure accumulator vessel 20 and the low-pressure accumulator vessel 31 are connected and joined at a T-joint, and a supply pipe 45 extending from the other end of the T-joint is connected to the dispenser 40, as shown in Fig. 1, is also suitable. When such a mode is adopted, a high-pressure air intake valve 41 is provided on the pipe connecting to the high-pressure accumulator vessel 20, and a low-pressure air intake valve 42 is provided on the pipe connecting to the low-pressure accumulator vessel 31, as a valve for switching the flow path for hydrogen supply. Furthermore, like the other pipes, the supply pipe 45 is constructed using conventionally known technology, but a structure capable of withstanding at least the pressure of the high-pressure hydrogen from the high-pressure accumulator vessel 20 is adopted. The opening and closing of the high-pressure air supply valve 41 and the low-pressure air supply valve 42 is controlled by the control unit 50, and is controlled based on a pressure value (hereinafter referred to as the ``switching reference value'') that serves as a reference when switching between the low-pressure accumulator vessel 31 and the high-pressure accumulator vessel 20.

[0043] The control unit 50 controls the flow path of hydrogen in the hydrogen gas station 1. The control unit 50 opens the inflow valve 3 when liquid hydrogen flows from the liquid hydrogen tank 2 into the vaporization unit 10, and closes the inflow valve when the inflow is to be stopped. The control unit 50 opens the high-pressure delivery valve 14 when sending high-pressure hydrogen from the vaporization unit 10 to the high-pressure accumulator vessel 20. Then, when the operation of sending hydrogen to the high-pressure accumulator vessel 20 is completed, the control unit 50 closes the high-pressure delivery valve 14 and opens the low-pressure delivery valve 15 to send the low-pressure hydrogen to the surge tank 30. The control unit 50 operates the heating means 43 and the cooling means 44 of the vaporization unit 10 as appropriate during the vaporization of liquid hydrogen by the vaporization unit 10 and the depressurization process within the vaporization unit 10 . When sending low-pressure hydrogen to the low-pressure accumulator vessel 31, the control unit 50 opens the accumulator valve 34 and operates the compressor 33. When hydrogen is sent to the hydrogen tank 46, the control unit 50 opens either the high-pressure air intake valve 41 or the low-pressure air intake valve 42 according to the values ​​of the pressure sensors A and B. As shown in FIG. 1, the control unit 50 controls the pressure sensors and control valves. Although not shown, the control unit 50 and each pressure sensor and control valve are connected by control lines, and reception of measurement data and opening and closing control of the control valves are performed via the control lines. Measurement data is sent to control unit 50 from pressure sensors provided in each part. Control unit 50 then determines the hydrogen flow path based on the received measurement data and data input in advance, and controls the opening and closing of the corresponding control valve. Control unit 50 controls the opening and closing of the flow path, making it possible to efficiently fill hydrogen in vaporization unit 10, as well as efficiently adjust the pressure for vaporization in vaporization unit 10 and fill hydrogen tank 46 with hydrogen. In FIG. 1, the control valves controlled by the control unit 50 are indicated by C.

[0044] The data input in advance to the control unit 50 is the first pressure value, the second pressure value, and the storage limit value of the surge tank 30 (the pressure value at which the pressure value in the surge tank 30 is considered to be lower than the pressure value in the vaporization unit 10), which are data necessary for vaporizing liquid hydrogen and selecting a filling destination for the vaporized hydrogen, and are input before vaporization by the vaporization unit 10.

[0045] When the control unit 50 determines the flow path to be used for filling the hydrogen tank 46, a decision to switch from the low-pressure accumulator vessel 31 to the high-pressure accumulator vessel 20 is made based on a switching reference value, and in addition to an embodiment in which the switching reference value is set to the same value as that of pressure sensor B, an embodiment in which the switching reference value is set to a value lower than the pressure value of the hydrogen stored in the low-pressure accumulator vessel 31 (for example, 0.9 times). For example, if the low-pressure accumulator vessel 31 is stored at 40 MPa, the switching reference value is set to 0.9 times, or 36 MPa, and the flow path is switched to the high-pressure accumulator vessel 20 side before the low-pressure accumulator vessel 31 and the hydrogen tank 46 reach the same pressure. By adopting such an embodiment, it is possible to increase the filling rate of the hydrogen tank 46 by switching to the high-pressure accumulator vessel 20 earlier while mitigating a decrease in the filling rate that can occur when the pressure difference between the low-pressure accumulator vessel 31 and the hydrogen tank 46 narrows.

[0046] Furthermore, before vaporization is performed by vaporization unit 10, control unit 50 receives the pressure values ​​of pressure sensors E, F, and G. At this time, if the pressure value of pressure sensor F is equal to or greater than the pressure value of pressure sensor G, or if the pressure value of pressure sensor E is equal to or greater than the specified storage value, although not shown, measures may be taken to reduce the pressure at the abnormal pressure location, such as opening an emergency discharge valve to release the hydrogen inside to the outside and reducing the pressure, or notifying an operator or manager of the abnormality and halting the vaporization operation.

[0047] The overall flow of vaporizing liquid hydrogen and filling with vaporized hydrogen will be described with reference to Figure 5. It is assumed that all control valves controlled by the control unit 50 are closed in the initial state. Control unit 50 confirms that the pressure value in vaporization unit 10 is equal to or lower than the second pressure value, and opens inflow valve 3 to allow liquid hydrogen to flow from the tank into vaporization unit 10 (S101). A predetermined amount of liquid hydrogen is introduced into vaporization unit 10 (S102). After that, inlet valve 3 is closed (S103), thereby preventing the vaporized hydrogen from flowing back into liquid hydrogen tank 2. Vaporization of liquid hydrogen begins in vaporization unit 10 (S104). The high-pressure delivery valve 14 is opened to start filling the high-pressure accumulator vessel 20 (S105). When vaporizing hydrogen in vaporization unit 10, control unit 50 operates heating means 43. Heating means 43 efficiently heats the inside of vaporization unit 10, thereby increasing the temperature of the liquid hydrogen and promoting vaporization, and also increasing the pressure inside vaporization unit 10 in a short period of time, thereby accelerating the filling speed into high-pressure accumulator vessel 20. The control unit 50 continues measurement by the pressure sensor F and compares it with the first pressure value (S106). The first pressure value is approximately the upper limit of the filling pressure of the high-pressure accumulator vessel 20. When the pressure value detected by the pressure sensor F reaches the first pressure value, it is determined that the filling of the high-pressure accumulator vessel 20 is complete, and the high-pressure delivery valve 14 is closed (S107). A pressure approximately equal to the upper filling pressure limit of the high-pressure accumulator vessel 20 is applied inside the vaporization unit 10, and in order to allow liquid hydrogen to flow from the liquid hydrogen tank 2 into the vaporization unit 10, the vaporization unit 10 must be lowered to a second pressure value or below. Therefore, by opening low-pressure delivery valve 15 and starting to store hydrogen in surge tank 30 (S108), the pressure inside vaporization unit 10 can be reduced to the second pressure value or less. When transferring hydrogen to surge tank 30, control unit 50 operates cooling means 44. Cooling means 44 efficiently cools the inside of vaporization unit 10, thereby lowering the temperature and pressure of hydrogen, smoothing the delivery of hydrogen to surge tank 30, and reducing the pressure inside vaporization unit 10 to below the second pressure value in a short period of time. In addition, a pressure adjustment unit 32 is provided upstream of the surge tank 30. By passing the hydrogen sent to the surge tank 30 through the pressure adjustment unit 32, the inflow pressure to the surge tank 30 can be kept below a certain level, thereby reducing the pressure burden on the surge tank 30. Thereafter, the control unit 50 continues measurement by the pressure sensor F and compares the measured pressure with the second pressure value (S109). When the pressure value measured by the pressure sensor F falls below the second pressure value, the low-pressure delivery valve 15 is closed (S110). The transfer of hydrogen to the surge tank 30 is completed. Next, the operation of transferring the hydrogen in the surge tank 30 to the low-pressure accumulator vessel 31 begins. First, the pressure accumulator valve 34 is opened to start storing hydrogen in the low-pressure accumulator vessel 31 (S111). The hydrogen in the surge tank passes through the low-pressure accumulator pipe 35, is pressurized to a predetermined pressure by the compressor 33, and is sent into the low-pressure accumulator vessel 31. The hydrogen in the surge tank 30 is sucked out by the compressor 33, so the pressure in the surge tank 30 gradually decreases. The control unit 50 compares the pressure value of the pressure sensor E with the storage specified value, and when the pressure value drops to the storage specified value, closes the pressure accumulation valve 34 (S113), completing the filling associated with evaporation.

[0048] Through this series of steps, the liquid hydrogen in the liquid hydrogen tank 2 is converted into gas in the vaporization unit 10 and filled into the high-pressure pressure accumulator vessel 20, and the remaining hydrogen in the vaporization unit 10 is also filled into the low-pressure pressure accumulator vessel 31, so there is no need to dispose of the hydrogen and it can be used efficiently.

[0049] Next, the operation of the vaporization unit 10 will be described with reference to FIG. As mentioned above, the vaporization unit 10 vaporizes liquid hydrogen that flows into the piping arranged in a ladder shape to high pressure. By using a ladder shape, it is relatively easy to create a structure that increases the surface area of ​​the piping while maintaining a certain level of strength. The more ladders there are, the greater the surface area can be, which is preferable. Naturally, the piping must be strong enough to withstand pressure equal to or greater than that inside the high-pressure accumulator vessel 20. The piping is surrounded by a heated or cooled medium. The vaporization standby state in the figure refers to a state in which the pressure accumulator is not being filled, all control valves provided on the piping connected to the vaporization unit 10 are closed, and the pressure inside the vaporization unit 10 is maintained at a second pressure value (S100). First, in order to vaporize liquid hydrogen in vaporization unit 10, inlet valve 3 is opened and liquid hydrogen flows from liquid hydrogen tank 2 into vaporization unit 10 (S101). After allowing a predetermined amount of liquid hydrogen to flow in, inlet valve 3 is closed, and vaporization of the liquid hydrogen begins in vaporization unit 10. At this time, the pressure inside the vaporization unit rises due to the vaporization of the liquid hydrogen. The piping is filled with a medium heated to a high temperature by heating means 43, and heat exchange with the medium raises the temperature of the liquid hydrogen, promoting vaporization. Then, as the liquid hydrogen vaporizes, high-pressure delivery valve 14 is opened, and filling of high-pressure accumulator vessel 20 with hydrogen begins (S102). When the vaporization of liquid hydrogen in the vaporization unit 10 is completed and the pressure value of the pressure sensor F reaches the first pressure value, it is determined that the filling of the high-pressure accumulator vessel 20 is completed, and the high-pressure delivery valve is closed (S103). The high-pressure hydrogen remaining in vaporization unit 10 has its temperature lowered by heat exchange with the medium cooled by the cooling means around the piping, which promotes a decrease in pressure value according to Henry's law. Then, low-pressure delivery valve 15 is opened to start filling surge tank 30, but by passing through pressure adjustment section 32, the pressure value of the low-pressure hydrogen being delivered is kept below a certain level, thereby lowering the pressure inside vaporization unit 10 (S104). When the pressure of pressure sensor F drops to the second pressure value, the low pressure delivery valve is closed, and the inside of vaporization unit 10 is placed in a vaporization standby state in which the second pressure value is maintained.

[0050] The heating means 43 heats the hydrogen in the vaporization unit 10, and the cooling means 44 cools the hydrogen in the vaporization unit 10. Heating is done to increase the efficiency of vaporizing the liquid hydrogen. Cooling occurs when the temperature of the hydrogen gas is lowered and the pressure of the hydrogen gas is reduced. By providing heating means 43, it is possible to increase the ambient temperature when vaporizing liquid hydrogen, thereby accelerating the vaporization rate and the rate at which the hydrogen pressure increases. In addition, by providing cooling means 44, it is possible to lower the temperature and pressure of hydrogen remaining in vaporization unit 10. Possible examples of the heating means 43 include hot water using a solar panel or the like, or warm air using an electric heater, etc. Possible examples of the cooling means 44 include cold water such as well water, tap water, or industrial water, or cold air using a blower fan or cooler, etc. Furthermore, the medium used for heating can be used for cooling, and the medium used for cooling can be used for heating, thereby enabling efficient use of energy.

[0051] FIG. 3 shows the pressure changes in the vaporization unit 10, the high-pressure accumulator vessel 20, the surge tank 30, and the low-pressure accumulator vessel 31 over time from the vaporization standby state in the vaporization unit 10 to after the supply to the surge tank 30 is stopped. The pressure change caused by filling the pressure accumulator with hydrogen will be described with reference to Fig. 3. The vaporization unit 10 is equipped with a cooling means 44. First, when vaporization unit 10 is in a vaporization standby state, the pressure inside vaporization unit 10 is maintained at a second pressure value (T100). When filling of the pressure accumulator vessel with hydrogen begins, first, liquid hydrogen flows into vaporization unit 10 and vaporization begins (T101). Simultaneously with the start of vaporization, high-pressure hydrogen also flows into and fills high-pressure accumulator vessel 20 (T102). Then, when the pressure inside vaporization unit 10 reaches a first pressure (T103), filling of high-pressure accumulator vessel 20 is considered to be complete (T104). After the filling of high-pressure accumulator vessel 20 is completed, vaporization unit 10 reduces the pressure by cooling means 44 (T105), and then low-pressure hydrogen is introduced into surge tank 30 to fill it (T106). When the pressure inside vaporization unit 10 reaches a second pressure value (T107), the pressure reduction inside vaporization unit 10 is considered to be complete, and filling of surge tank 30 also ends (T108). Thereafter, the low-pressure hydrogen inside surge tank 30 is filled into low-pressure accumulator vessel 31 (T109), and the pressure inside surge tank 30 decreases.

[0052] The timing of switching the pressure accumulator when hydrogen is filled into the hydrogen tank 46 will be described with reference to Figure 4. The switching reference value is calculated as the low-pressure hydrogen pressure B filled in the low-pressure accumulator vessel 31 x 0.9. First, the pressure inside the hydrogen tank 46 is measured by pressure sensor A (T201). Because the pressure value of pressure sensor A is below the switching reference value, the flow path from the low-pressure accumulator vessel 31 is opened and low-pressure hydrogen is filled into the hydrogen tank 46 (T202). When the pressure value of pressure sensor A reaches the switching reference value (T203), the flow path from the low-pressure accumulator vessel 31 is blocked (T204), and the flow path from the high-pressure accumulator vessel 20 is opened (T205), and high-pressure hydrogen is filled into the hydrogen tank 46. When the pressure value of pressure sensor A reaches the specified filling value (T206), the flow path from the high-pressure accumulator vessel 20 is closed (T207), and filling of the hydrogen tank 46 is completed.

[0053] The operation of the hydrogen gas station 1 according to the present invention will be described below. First, the operation of filling the pressure accumulator vessel with hydrogen will be described. The hydrogen stored in the liquid hydrogen tank 2 vaporizes as it flows into the vaporization unit 10, and the high-pressure hydrogen is filled into the high-pressure accumulator vessel 20. After filling into the high-pressure accumulator vessel 20, the low-pressure hydrogen remaining in the vaporization unit 10 flows into the surge tank 30 and is temporarily stored therein before being filled into the low-pressure accumulator vessel 31. The control unit 50 controls the valves to form the flow paths in each operation.

[0054] Next, the operation of filling the hydrogen tank 46 will be described. First, the dispenser 40 and the hydrogen tank 46 are connected, the pressure value of the hydrogen tank 46 is measured, and the pressure value of the low-pressure accumulator vessel 31 is measured, and a switching reference value is set. If the pressure value of the hydrogen tank 46 is lower than the switching reference value, the flow path from the low-pressure accumulator vessel 31 is opened, and low-pressure hydrogen is allowed to flow into the hydrogen tank 46. Thereafter, when the switching reference value is reached due to filling, the flow path from the low-pressure accumulator vessel 31 is closed, and the flow path from the high-pressure accumulator vessel 20 is opened, and high-pressure hydrogen is allowed to flow into the hydrogen tank 46. If the pressure value of pressure sensor A is higher than the switching reference value, the flow path from the high-pressure accumulator vessel 20 is opened, allowing high-pressure hydrogen to flow into the hydrogen tank 46. When the pressure value of pressure sensor A reaches the specified filling value, the flow paths from the high-pressure accumulator vessel 20 and the low-pressure accumulator vessel 31 are blocked, and filling of the hydrogen tank 46 is completed. The control unit 50 performs valve operations for forming flow paths to the high-pressure accumulator vessel 20 and the low-pressure accumulator vessel 31 and for switching the flow paths.

[0055] The basic configuration and operation of the hydrogen gas station 1 according to the present invention have been described above, but the present invention is not limited to the configuration shown in the above embodiment and drawings. For example, when a customer requests that a specified amount of hydrogen be filled, a suitable configuration is one in which the high-pressure air supply valve 41 is opened without measuring the pressure in the low-pressure accumulator vessel 31, and hydrogen released from the high-pressure accumulator vessel 20 is filled into the hydrogen tank 46, thereby increasing the hydrogen supply rate. In addition, the low-pressure accumulator vessel 31 filled with low-pressure hydrogen can also be suitably used as a hydrogen container for power generation by connecting it to a power generation facility using a fuel cell, or as a fuel container for a gas burner used as heating means 43.

[0056] As described above, the hydrogen gas station 1 of the present invention has the excellent effect of lowering the pressure within the vaporization unit 10 and enabling the hydrogen remaining in the vaporization unit 10 to be used without being discarded by flowing the hydrogen remaining in the vaporization unit 10 into the surge tank 30 as low-pressure hydrogen. [Industrial Applicability]

[0057] The present invention is a hydrogen gas station that can be operated without using a high-performance compressor, etc., and can be used as a method for effectively storing hydrogen and supplying hydrogen to hydrogen-powered vehicles. Therefore, it is believed that the "hydrogen gas station" according to the present invention has great industrial applicability. [Explanation of symbols]

[0058] 1 Hydrogen Gas Station 2 liquid hydrogen tanks 3 Inlet Valve 4 Inflow pipe 10 Vaporization Unit 12 High-pressure pipe 13 Low-pressure pipe 14 High pressure delivery valve 15 Low pressure delivery valve 20 High-pressure accumulator vessel 30 Surge Tank 31 Low-pressure accumulator vessel 32 Pressure adjustment section 33 Compressor 34 Accumulator valve 35 Low-pressure accumulator pipe 40 Dispenser 41 High pressure air intake valve 42 Low pressure air intake valve 43 Heating means 44 Cooling means 45 Supply pipe 46 Hydrogen Tank 50 control section A Pressure sensor (hydrogen tank) B Pressure sensor (low-pressure accumulator) D Pressure sensor (high-pressure accumulator vessel) E Pressure sensor (surge tank) F Pressure sensor (vaporization unit) G Pressure sensor (liquid hydrogen tank)

Claims

1. a liquid hydrogen tank for storing liquid hydrogen, a vaporization unit for vaporizing the liquid hydrogen flowing from the liquid hydrogen tank, a pressure sensor for detecting the hydrogen pressure value within the vaporization unit, a high-pressure accumulator vessel for storing high-pressure hydrogen vaporized in the vaporization unit, a surge tank for storing low-pressure residual hydrogen vaporized in the vaporization unit after filling the high-pressure accumulator vessel, a low-pressure accumulator vessel for storing low-pressure residual hydrogen delivered from the surge tank, a dispenser for supplying hydrogen stored in the high-pressure accumulator vessel or the low-pressure accumulator vessel to the hydrogen tank of a hydrogen vehicle, and a control unit; A hydrogen gas station characterized in that, when the pressure sensor detects that the pressure has risen to a first pressure value, the control unit closes the flow path from the vaporization unit to the high-pressure accumulator vessel and opens the flow path from the vaporization unit to the surge tank, and when the pressure sensor detects that the pressure has subsequently fallen to a second pressure value, the control unit closes the flow path from the vaporization unit to the surge tank and opens the flow path from the vaporization unit to the low-pressure accumulator vessel.

2. 2. The hydrogen gas station according to claim 1, wherein the low-pressure pipe arranged between the vaporization unit and the surge tank has a larger pipe diameter than the high-pressure pipe arranged between the vaporization unit and the high-pressure accumulator vessel.

3. A pressure adjusting unit is provided upstream of the surge tank, 2. The hydrogen gas station according to claim 1, wherein the control unit closes the flow path to the high-pressure accumulator vessel and opens the flow path to the pressure adjustment unit when filling of the high-pressure accumulator vessel is completed.

4. 2. The hydrogen gas station according to claim 1, wherein a compressor is provided downstream of the surge tank.

5. 2. The hydrogen gas station according to claim 1, further comprising a cooling means for cooling the vaporization unit.

6. 2. The hydrogen gas station according to claim 1, further comprising a heating means for heating the vaporization unit.

7. The hydrogen vehicle has a pressure sensor A that detects the pressure inside the hydrogen tank and a pressure sensor B that detects the pressure in the low-pressure accumulator vessel, 2. The hydrogen gas station according to claim 1, wherein the control unit opens the flow path of the low-pressure accumulator vessel when the detection results of pressure sensor A and pressure sensor B show that the pressure value of pressure sensor A is lower than the pressure value of pressure sensor B.

8. storing liquid hydrogen in a liquid hydrogen tank; a step of vaporizing the liquid hydrogen flowing in from the liquid hydrogen tank in a vaporization unit; detecting a hydrogen pressure value in the vaporization unit by a pressure sensor; storing high-pressure hydrogen vaporized in the vaporization unit in a high-pressure accumulator vessel; storing in a surge tank the low-pressure residual hydrogen vaporized by the vaporization unit after filling the high-pressure accumulator vessel; storing the low-pressure residual hydrogen delivered from the surge tank in a low-pressure accumulator vessel; a step of supplying hydrogen stored in a high-pressure accumulator vessel or a low-pressure accumulator vessel from a dispenser to a hydrogen tank of a hydrogen vehicle; a step of closing a flow path from the vaporization unit to the high-pressure accumulator vessel and opening a flow path from the vaporization unit to the surge tank in the control unit when the pressure detected by the pressure sensor reaches a first pressure value; A method for operating a hydrogen gas station, comprising the steps of: in a control unit, when the detection result of the pressure sensor after the previous step has dropped to a second pressure value, closing the flow path from the vaporization unit to the surge tank and opening the flow path from the vaporization unit to the low-pressure accumulator vessel.

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