Hydrogen gas supply method and hydrogen gas supply system

Abstract

Provided is a hydrogen gas supply method and system that can stably compress hydrogen gas regardless of whether the pressure is low or high and has excellent reliability. [Solution] The hydrogen gas supply method and supply system of the present invention comprises a low-pressure compressor 1 and a high-pressure compressor 2 that compress hydrogen gas, and the required pressure of the supply destination has a low-pressure region and a high-pressure region, and is a supply method of hydrogen gas that supplies to the supply destination in accordance with the required pressure, wherein the low-pressure compressor 1 is a piston crank type compressor and the high-pressure compressor 2 is a hydraulic compressor or a diaphragm type compressor, and when the required pressure of the supply destination is in the low-pressure region, hydrogen gas compressed by the low-pressure compressor 1 is supplied to the supply destination.

Description

[Technical field]

[0001] The present invention relates to a hydrogen gas supply method and a hydrogen gas supply system, and more particularly to a hydrogen gas supply method and a hydrogen gas supply system that can stably compress hydrogen regardless of whether it is at low pressure or high pressure, and can satisfy customers' requests for rapid hydrogen filling. [Background technology]

[0002] In recent years, the development of fuel cell vehicles (FCVs), which use hydrogen gas as a power source, has progressed and is approaching the stage of practical application. Hydrogen gas is supplied to the hydrogen tank of a fuel cell vehicle at a hydrogen filling station, just as gasoline is supplied to a gasoline vehicle at a gas station.

[0003] Some hydrogen stations are on-site type, which are equipped with hydrogen production equipment and supply hydrogen produced by that equipment, but in order to reduce equipment costs, there are also off-site type hydrogen stations that use a cardle containing multiple gas containers (red) as the hydrogen supply source, which produces hydrogen outside the facility.

[0004] Patent Document 1 discloses a method in which, when producing high-pressure hydrogen gas, a hydraulic booster type compressor is used to boost the pressure to, for example, more than 82 MPa and store the pressure in a pressure accumulator, and, when producing medium-pressure hydrogen gas, a hydraulic booster type compressor is used to boost the pressure to, for example, 40 MPa and store the pressure in a pressure accumulator for use. However, hydraulic compressors are mechanisms that drive pistons using the hydraulic force of hydraulic oil, and due to restrictions such as sealing of hydraulic oil, the maximum number of cycles is smaller than that of piston crank compressors that have a crank mechanism. Therefore, compared to the piston crank type, there is a drawback in that the flow rate per compressor is smaller when increasing pressure from low to high.

[0005] Patent Document 2 discloses a method of five-stage compression using a crank-type compressor. Specifically, the compressor has cylinders extending radially around a crank-type rotary drive unit, and each cylinder is equipped with a piston. The five-stage compression increases the pressure from 0.6 MPa to 145.8 MPa. The piston crank type can compress a large flow rate from low pressure because it can handle a large number of cycles. Hydrogen stations use ultra-high pressure compression of over 80 MPa.

[0006] Patent Document 3 also uses a crank-type compressor at high pressures of 50 MPa or more, and in this type of hydrogen station, a crank-type compressor is sometimes used even at high pressures of 50 MPa or more. However, according to the inventors' investigations, there are concerns that ultra-high pressure compression may result in shorter life spans and reduced reliability of wear parts compared to low pressure compression. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2021-139378 A [Patent Document 2] JP 2016-183684 A [Patent Document 3] JP 2023-67967 A Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, an object of the present invention is to provide a hydrogen gas supply method and hydrogen gas supply system that can stably compress hydrogen regardless of whether it is at low pressure or high pressure and is highly reliable. Further objects of the present invention will become apparent from the following description. [Means for solving the problem]

[0009] The above problems are solved by the following inventions.

[0010] 1. Equipped with a low-pressure compressor and a high-pressure compressor to compress hydrogen gas, A method for supplying hydrogen gas to a destination in accordance with a required pressure, the required pressure of which has a low pressure region and a high pressure region, the low-pressure compressor is a piston crank compressor, The high-pressure compressor is a hydraulic compressor or a diaphragm compressor, When the required pressure of the supply destination is in a low pressure region, the hydrogen gas compressed by the low pressure compressor is supplied to the supply destination; A method for supplying hydrogen gas, characterized in that, when the required pressure of the supply destination is in the high pressure region, hydrogen gas is compressed by the low pressure compressor, the compressed hydrogen gas is introduced into the high pressure compressor, and the hydrogen gas compressed by the high pressure compressor is supplied to the supply destination. 2. 2. The method for supplying hydrogen gas according to claim 1, wherein the destination of the hydrogen gas supply is a pressure accumulator at a hydrogen station or a hydrogen storage tank of a mobile body. 3. The method of filling the hydrogen storage tank is as follows: Low pressure compressor and high pressure compressor Direct charging method from the pressure vessel or differential pressure charging method from the pressure vessel, or both the direct charging method and the differential pressure charging method Use in combination with The above-mentioned 2 The method for supplying hydrogen gas described above. 4. The method for supplying hydrogen gas described in item 1, wherein the low pressure region of the required pressure at the destination is a region having an upper limit of any value between 40 and 50 MPa, and the high pressure region is a region greater than any upper limit value of the low pressure region and not greater than 100 MPa. 5. 2. The method for supplying hydrogen gas according to claim 1, wherein the piston crank compressor and the hydraulic compressor or the diaphragm compressor share a single electric motor. 6. The present invention is characterized in that a clutch is provided for controlling ON / OFF of the drive of the hydraulic compressor or the diaphragm compressor. 5The method for supplying hydrogen gas described above. 7. The hydrogen gas supply method described in 1 above, characterized in that the piston crank type compressor and the hydraulic compressor or diaphragm type compressor are mounted together, and common auxiliary equipment is shared to form a unit of a size that can fit on the same skid. 8. The hydrogen gas flow rate that can be supplied to the destination is 400 Nm 3 / Hr~1200Nm 3 2. The method for supplying hydrogen gas according to item 1, wherein the hydrogen gas supply rate is 1 / Hr. 9. Equipped with a low-pressure compressor and a high-pressure compressor to compress hydrogen gas, A hydrogen gas supply system in which the required pressure of a supply destination has a low pressure region and a high pressure region, and the hydrogen gas supply system supplies the hydrogen gas to the supply destination in accordance with the required pressure, the low-pressure compressor is a piston crank compressor, The high-pressure compressor is a hydraulic compressor or a diaphragm compressor, When the required pressure of the supply destination is in the low pressure region, the hydrogen gas compressed by the low pressure compressor is supplied to the supply destination; A hydrogen gas supply system characterized by compressing hydrogen gas by the low-pressure compressor when the required pressure of the supply destination is in the high-pressure region, introducing the compressed hydrogen gas into the high-pressure compressor, and supplying the hydrogen gas compressed by the high-pressure compressor to the supply destination. 10. 10. The hydrogen gas supply system according to claim 9, wherein the destination of the hydrogen gas supply is a pressure accumulator at a hydrogen station or a hydrogen storage tank of a mobile body. 11. The method of filling the hydrogen storage tank is as follows: Low pressure compressor and high pressure compressor 11. The hydrogen gas supply system according to claim 10, characterized in that it employs a direct filling method from the pressure vessel, or a differential pressure filling method via the pressure vessel, or a combination of the direct filling method and the differential pressure filling method. 12. The hydrogen gas supply system described in item 9, characterized in that the low pressure region of the required pressure at the destination is a region where the upper limit value is any value between 40 and 50 MPa, and the high pressure region is a region that is greater than any value of the upper limit value of the low pressure region and is not greater than 100 MPa. 13. The hydrogen gas supply system according to claim 9, wherein the piston crank compressor and the hydraulic compressor or the diaphragm compressor share a single electric motor. 14. 14. The hydrogen gas supply system according to claim 13, further comprising a clutch for controlling ON / OFF of the drive of the hydraulic compressor or diaphragm compressor. 15. 10. The hydrogen gas supply system described in claim 9, characterized in that the piston crank type compressor and the hydraulic compressor or diaphragm type compressor are mounted together and common auxiliary equipment is shared, forming a compressor unit of a size that can fit on the same skid. 16. The hydrogen gas flow rate that can be supplied to the destination is 400 Nm 3 / Hr~1200Nm 3 10. The hydrogen gas supply system according to item 9, wherein the hydrogen gas supply rate is 100 / Hr. 17. a motor pulley (102) provided on a drive shaft (101) of the electric motor (100); a piston crank compressor pulley (103) provided on a piston crank compressor side drive shaft (107) of the piston crank compressor (1); a hydraulic compressor pulley (105) provided on a hydraulic compressor-side drive shaft (108) of the hydraulic compressor (2), The motor pulley (102) and the piston crank compressor pulley (103) are rotatably connected to each other via a piston crank compressor belt (104). The motor pulley (102) and the hydraulic compressor pulley (105) are rotatably connected to each other via a hydraulic compressor belt (106). The piston crank compressor (1) is structured so that the rotation of a drive shaft by the drive of an electric motor is converted into linear reciprocating motion of a piston via a crankshaft, and compresses hydrogen gas filled above the piston in a cylinder. The hydraulic compressor (2) is configured such that the rotation of the drive shaft by the drive of an electric motor is converted into reciprocating motion of a piston by the hydraulic pressure generated by driving a hydraulic pump, and the reciprocating motion of the piston compresses the hydrogen gas filled in the cylinder. 18. a piping system (110) that leads to a suction side of the hydraulic compressor (2) that compresses high pressure hydrogen via low pressure compression of the piston crank compressor (1) and leads to the hydraulic compressor (2); and a branch piping system (111) that bypasses the hydraulic compressor (2) and leads to a discharge side of the hydraulic compressor (2) without passing through the piston crank compressor (1) and entering the suction side of the hydraulic compressor (2), a control valve (112) for controlling opening and closing of the branch piping system (111); a clutch (109) for disconnecting the driving force of the electric motor (105) of the hydraulic compressor (2) from a drive shaft (108) of the hydraulic compressor (2); The above Supply destination When the required pressure is equal to or lower than the set value, the clutch (109) is disengaged and the control valve (112) is opened. The above Supply destination When the required pressure becomes greater than the set value, the clutch (109) is engaged and the control valve (112) is closed. 9 The hydrogen gas supply system described herein. Effect of the Invention

[0011] According to the present invention, it is possible to provide a hydrogen gas supply method and a hydrogen gas supply system that can stably compress hydrogen regardless of whether the pressure is low or high and that are highly reliable.

[0012] Furthermore, according to the present invention, it is possible to provide a hydrogen gas supply method and a hydrogen gas supply system that enable stable filling of large volumes of hydrogen at hydrogen stations and that also provides excellent customer satisfaction. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic side view showing an example of a hydrogen station to which the present invention is preferably applied, showing a direct charging system. [Diagram 2] FIG. 1 is a schematic side view showing another example of a hydrogen station to which the present invention is preferably applied, showing a differential pressure filling method. [Diagram 3] FIG. 1 is a schematic cross-sectional view showing an example of a piston crank compressor. [Figure 4] Schematic cross-sectional view showing an example of a hydraulic compressor. [Diagram 5] Schematic cross-sectional view showing an example of a diaphragm compressor. [Figure 6] FIG. 1 is a diagram illustrating an embodiment in which a motor is shared between a low-pressure hydrogen compressor and a high-pressure hydrogen compressor. [Figure 7] FIG. 1 is a diagram illustrating an embodiment in which a motor is shared between a low-pressure hydrogen compressor and a high-pressure hydrogen compressor. [Figure 8] FIG. 1 is a diagram showing an example of a control flow for starting a compressor in a hydrogen gas supply system according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Preferred embodiments of the present invention will now be described. 1 and 2 are schematic side views showing an example of a hydrogen station to which the present invention is preferably applied. The example in FIG. 1 shows a direct filling method, and the example in FIG. 2 shows a differential pressure filling method.

[0015] Explaining with reference to Figs. 1 and 2, the compressor includes a piston crank type compressor 1 which is a low pressure hydrogen compressor, and a hydraulic compressor 2 which is a high pressure hydrogen compressor.

[0016] FIG. 1 shows an example of a direct filling method in which hydrogen gas produced by compression using a low-pressure hydrogen compressor 1 and a high-pressure hydrogen compressor 2 is filled into a hydrogen storage tank of a mobile object 4 via a dispenser 3.

[0017] FIG. 2 shows an example of a differential pressure filling method in which hydrogen gas produced by compression using a compressor is first supplied to a pressure accumulator 5, and then filled from the pressure accumulator 5 into a hydrogen storage tank of a mobile object 4 via a dispenser 3.

[0018] As shown in FIGS. 1 and 2, hydrogen gas supplied from a compressor is supplied to a pressure accumulator 5 in a hydrogen station or a hydrogen storage tank in a mobile object 4. Hydrogen gas can be filled into the hydrogen storage tank of the mobile object 4 by a direct filling method in which hydrogen is filled from a compressor via a dispenser 3 as shown in FIG. 1, or a differential pressure filling method in which hydrogen is supplied from a compressor to a pressure accumulator 5 as shown in FIG. 2 and then filled from the pressure accumulator 5 via a dispenser 3, or a combination of the direct filling method and the differential pressure filling method.

[0019] In this embodiment, an example is shown in which hydrogen gas, which serves as fuel, is supplied from a compressor to the destination, which is a pressure accumulator 5 or a hydrogen storage tank of a mobile object 4, at a hydrogen station. However, this is not limited to this, and the destination of the hydrogen gas is not limited to a hydrogen station. The hydrogen gas can also be compressed and supplied to a storage tank for transporting hydrogen. Hereinafter, the hydrogen gas supply method and system of the present invention will be described taking as an example a case where the destination of the supply of hydrogen gas as fuel is a hydrogen storage tank.

[0020] In the hydrogen gas supply method and supply system of the present invention, while the required or necessary hydrogen gas pressure in the hydrogen storage tank is in the low pressure region (for example, about 0 to 50 MPa), low-pressure compressed hydrogen produced by driving a crank compressor is supplied to the hydrogen storage tank. As more hydrogen gas is supplied into the tank and the volume of hydrogen in the tank increases, the pressure in the tank increases, and accordingly the required pressure of the hydrogen storage tank also increases. In other words, the required pressure of the tank varies depending on the pressure inside the tank, which varies depending on the volume of hydrogen gas inside the tank, and the more hydrogen gas is supplied to the tank, the higher the required pressure of the tank becomes.

[0021] In the present invention, the required pressure of the supply destination is divided into two regions, a low pressure region and a high pressure region, and in the case of the low pressure region, the pressure of the hydrogen gas compressed by the low pressure compressor is sufficient to supply the hydrogen gas to the supply destination, so there is no need to start up the high pressure compressor.

[0022] In this specification, when the required pressure at the destination is in the low pressure region, supplying hydrogen gas compressed by the low pressure compressor to the destination means that the pressure of the hydrogen gas compressed by the low pressure compressor is sufficient to supply it to the destination, and therefore there is no need to perform compression processing using a high pressure compressor.

[0023] "There is no need to perform compression processing in the high-pressure compressor" includes the case where hydrogen gas is introduced into the high-pressure compressor and the hydrogen gas flows through the high-pressure compressor without substantially increasing the pressure. The hydrogen gas introduced into the high-pressure compressor is used as a flow path through the high-pressure compressor without being compressed. "There is also no need to perform compression processing in the high-pressure compressor" includes the case where the flow path is switched without introducing the hydrogen gas into the high-pressure compressor by using a control valve described later.

[0024] In this embodiment, when the required pressure of the supply destination is in the low pressure region and has not yet reached the high pressure region, hydrogen can be supplied to the supply destination as long as the pressure of the hydrogen supplied from the compressor is slightly higher than the required pressure of the supply destination, so that hydrogen gas can be supplied to the supply destination without being compressed by the high pressure compressor. Therefore, in this case, only the low pressure compressor is operated, and the high pressure compressor is not operated (the clutch described below is disengaged and the driving force is not transmitted). This has the effect of significantly reducing power costs because the high pressure compressor is not operated. Also, by not operating the high pressure compressor, if the sliding parts of the high pressure compressor, such as the piston, can be stopped, there is the effect of reducing wear.

[0025] On the other hand, in the case of high pressure regions, the pressure of the hydrogen gas compressed by the low pressure compressor is insufficient to supply the hydrogen gas to the destination, so the destination is not filled with hydrogen gas. For this reason, by introducing the hydrogen gas compressed by the low pressure compressor into the high pressure compressor and compressing it with the high pressure compressor, it is possible to increase the pressure to a level where hydrogen gas can be supplied to the destination, even in the case of high pressure regions.

[0026] When the hydrogen gas pressure in the hydrogen storage tank to which the hydrogen is to be supplied is in the high-pressure range (for example, about 50 to 100 MPa), the hydrogen gas is compressed to a pressure of 50 MPa by operating the low-pressure compressor, and then the high-pressure compressor is operated by operating the electric motor of the high-pressure compressor or by engaging the clutch, and the hydrogen gas that has reached a pressure of 50 MPa in the low-pressure compressor is further compressed to a high pressure and supplied to the hydrogen storage tank to which the hydrogen is to be supplied.

[0027] In the present invention, depending on the required pressure of the hydrogen storage tank, when the required pressure is in the low pressure region, the piston crank type compressor is driven to compress the hydrogen gas, and the hydrogen storage tank, which is the supply destination, is filled with hydrogen gas without driving the hydraulic compressor or diaphragm type compressor. Next, when the required pressure exceeds the low pressure region and reaches the high pressure region, the electric motor of the high pressure compressor is operated (the clutch is engaged to transmit driving force to the high pressure compressor), the hydrogen gas is compressed by the low pressure compressor, and the hydrogen gas compressed by the low pressure compressor is introduced into the high pressure compressor, which compresses the hydrogen gas so that its pressure exceeds the required pressure of the supply destination, and the hydrogen gas is filled.

[0028] The piston crank compressor 1 used in the low-pressure compressor may have a plurality of compression stages, and preferably has, for example, three or four stages. The hydraulic compressor 2 used in the high pressure compressor may be of single stage or two stages. The total number of stages in the compressor including the low-pressure compressor and the high-pressure compressor may be five stages or about six to eight stages.

[0029] In the present invention, the upper limit of the low-pressure region of the hydrogen gas pressure in the hydrogen storage tank is preferably 40 to 50 MPa. This upper limit varies depending on the design value of the compression capacity of the low-pressure compressor. The upper limit of the low-pressure region in the present invention is approximately equal to the upper limit of the hydrogen gas pressure that can be compressed by the low-pressure compressor. On the other hand, the high pressure region of the hydrogen gas pressure in the hydrogen storage tank is preferably a region higher than the upper limit of the low pressure region and equal to or lower than 100 MPa. In this embodiment, the low pressure region has an upper limit of any value in the range of 40 to 50 MPa, and the high pressure region has a lower limit of a value greater than the upper limit of the low pressure region, with an upper limit of up to 100 MPa.

[0030] The gas pressure of the low-pressure hydrogen compressor 1 is in the range of 0.6 to 50 MPa, and the upper limit of the gas pressure of the high-pressure hydrogen compressor 2 is in the range of 100 MPa. Since the low-pressure hydrogen compressor 1 boosts the gas pressure in multiple stages as described above, it is possible to boost the gas pressure to any desired level by designing the boost ratio according to the number of stages. In this embodiment, the high-pressure hydrogen compressor 2 is a compressor for further boosting and supplying hydrogen when the pressure supplied by the low-pressure hydrogen compressor 1 is insufficient, for example, when the necessary pressure (required pressure) of the supply destination is in the high-pressure region. Therefore, the lower limit of the gas pressure of the high-pressure hydrogen compressor 2 is variable depending on the upper limit of the low-pressure hydrogen compressor 1.

[0031] The hydrogen gas flow rate that can be supplied to the hydrogen storage tank is 400 to 1200 Nm3 under standard conditions for the entire compressor. 3 / Hr. According to the present invention, even if 3 to 8 moving objects such as automobiles enter a hydrogen station at the same time and request hydrogen filling, the large hydrogen gas flow rate allows for smooth filling without congestion, making it possible to provide a system with excellent practicality.

[0032] Hydrogen to be compressed is usually brought to the hydrogen station in a curdle (a combination of hydrogen produced outside and multiple gas containers (red)). In addition to curdles, hydrogen may be supplied to the hydrogen station by pipeline.

[0033] Hydrogen is produced outside and brought to the hydrogen station in gaseous form, but it may also be liquefied hydrogen. In addition, a hydrogen production device may be installed at the hydrogen station and hydrogen produced by the device may be used. Examples of hydrogen production devices include a device that produces hydrogen gas by installing a water electrolyzer and using an external power source, a hydrocarbon fuel cracking device, and a device that produces hydrogen gas by installing a liquefied hydrogen storage container filled with liquefied hydrogen and using a vaporizer.

[0034] In the hydrogen gas supply method and system of the present invention, the mobile object 4 may be a fuel cell vehicle or a ship that uses hydrogen as fuel. Since the present invention can supply a large flow rate of hydrogen gas, it is suitable for use in large-capacity tanks in buses and trucks.

[0035] Furthermore, the hydrogen gas supply system realizing the hydrogen gas supply method of the present invention is small enough to fit on the same skid. The size that can fit on the same skid is, for example, a size that can fit in a 20 ft container, and specifically, the inner floor area of ​​a 20 ft container is exemplified, but is not limited to this. The hydrogen station in which the present invention is installed is not limited to being installed on land, but may also be installed on the sea, and may be either a fixed type or a mobile type.

[0036] FIG. 3 is a schematic cross-sectional view showing an example of a piston crank type compressor. In Fig. 3, a piston 11 is provided inside a cylinder 10, and a piston ring 12 is provided to prevent leakage from the outer periphery of the piston 11 to some extent. A plurality of piston rings 12 can be provided. In the example shown, two rings are provided. The lower part of the piston 11 is supported by a piston rod 13. The piston rod 13 is connected to a crankshaft 15 via a connecting rod 14.

[0037] The crankshaft 15 is rotatably connected to a compressor motor (not shown), and the rotation of the motor rotates the crankshaft 15, which converts the motion of the piston rod 13 into linear reciprocating motion, causing it to move up and down.

[0038] When the crankshaft 15 rotates, the piston rod 13 moves up and down, and the piston 11 moves up and down accordingly, so that the hydrogen gas filled above the piston 11 is compressed.

[0039] FIG. 4 is a schematic cross-sectional view showing an example of a hydraulic compressor. In FIG. 4, pressure of oil working fluid 16 is applied from below to a piston 11 equipped with a piston seal 16 provided in a cylinder 10. The oil working fluid 16 is sent from a hydraulic pump 170 , and the pump pressure of the hydraulic pump 170 presses the piston 11 upward, compressing the hydrogen gas filled above the piston 11 in the cylinder 10 .

[0040] The hydraulic pump 170 has two gears 172 and 173 that mesh with each other in an external contact state so that their outer surfaces are in contact with each other inside a casing 171. The gear 172 is a drive gear, and the gear 173 is a driven gear.

[0041] When the meshing parts separate due to rotation, a space is created, and the oil is sucked in. In this way, the space is filled with oil. The oil is guided along the inner surface 175 of the casing 171 to the discharge side 176. The meshing parts separate the suction side 177 from the discharge side 176.

[0042] The drive gear 172 is configured to be rotatable by a rotary shaft connected to an electric motor (not shown). When a drive gear 172 of the illustrated gear pump 170 rotates, the oil pushed out from the gear pump 172 presses the working fluid 17 shown in FIG.

[0043] Pressure is applied to the oil working fluid 17 from below the piston 11 equipped with a piston seal 16 provided in the cylinder 10. In this manner, the oil working fluid 17 presses the piston 11 upward by the pump pressure of the gear pump 172, which is a hydraulic pump, and compresses the hydrogen gas filled above the piston 11 in the cylinder 10.

[0044] In the case of a mechanical drive without oil hydraulic fluid, there is no object for leakage into the cylinder 10, so there is no risk of leakage from the piston ring 12 shown in Figure 3. As a result, the load is not as large as with a hydraulic system, so the piston speed can be increased. On the other hand, in the case of a hydraulic system, since it is necessary to prevent leakage of the oil working fluid 17 to the process side, it is preferable to select a piston seal 16 with high sealing performance. As a result, it is preferable to keep the piston speed low in order to prevent wear and damage to the piston seal 16.

[0045] In the illustrated example, the oil working fluid is pressurized using a gear pump, and the pressurized oil working fluid pressurizes a piston upward, thereby compressing hydrogen gas. However, any form can be used as long as pressure can be applied to the oil working fluid by using the power of the electric motor via the drive shaft, and the present invention is not limited to a gear pump as illustrated in the example.

[0046] Also, a booster type hydraulic compressor that does not use a hydraulic pump that directly applies oil working fluid can be used. This booster type hydraulic compressor applies pressure of oil working fluid pressurized by compressed air from below the piston, for example, to reciprocate the piston and compress the hydrogen gas filled above the piston in the cylinder. In this case, the air for compressing the oil working fluid can be compressed by transmitting the power of the electric motor via the drive shaft.

[0047] FIG. 5 is a schematic cross-sectional view showing an example of a diaphragm compressor. In FIG. 5, the piston rod 13 supporting the diaphragm 18 is caused to reciprocate (move up and down) to cause the diaphragm 18 to reciprocate (move up and down), thereby compressing the hydrogen gas filled above the diaphragm 18 inside the cylinder 10. This compressor compresses air by changing the volume by moving a metal film called a diaphragm up and down. It has the advantage of having no sliding parts such as pistons and no lifespan due to wear, but on the other hand, the diaphragm type compressor has a limited fatigue life because the volume changes due to the elastic deformation of the diaphragm 18.

[0048] In the present invention, low pressure compression and high pressure compression are performed using different types of compressors. Hydraulic compressors have a mechanism that drives pistons using the hydraulic force of hydraulic oil, and due to restrictions such as sealing of hydraulic oil, the maximum number of cycles is smaller than that of piston crank compressors with a crank mechanism. Therefore, compared to piston crank types, they have the characteristic of having a smaller flow rate per compressor when increasing pressure from low to high.

[0049] However, the piston crank type can compress a large flow rate when compressing from a low pressure because it can have a large number of cycles. At hydrogen stations, ultra-high pressure compression of over 80 MPa is achieved using a piston crank compressor. When piston crank compressors are used with high pressures of 50 MPa or more, there are concerns that the life span and reliability of wear parts will be shortened compared to when they are used with low pressures of 50 MPa or less. In contrast, hydraulic compressors are superior in that they do not suffer from the above problems in the high pressure and ultra-high pressure ranges. Therefore, the present invention takes advantage of the characteristics of both and provides a hydrogen gas supply method and system that has a high flow rate, is reliable, and is easy to use by placing a crank compressor in the front stage and a hydraulic compressor or a diaphragm compressor in the rear stage.

[0050] Next, an embodiment in which the low-pressure hydrogen compressor (piston crank type compressor) and the high-pressure hydrogen compressor (hydraulic compressor) share a single electric motor will be described with reference to Figs. Sharing an electric motor means that instead of providing separate electric motors for the low-pressure compressor and the high-pressure hydrogen compressor, only one electric motor is used to drive both the low-pressure compressor and the high-pressure hydrogen compressor, thereby compressing both low-pressure and high-pressure hydrogen. Since the low-pressure hydrogen compressor is a piston crank type compressor and the high-pressure hydrogen compressor is a hydraulic compressor or a diaphragm type compressor, sharing an electric motor means that instead of providing separate electric motors for the piston crank type compressor and the hydraulic compressor, only one electric motor is provided to drive both the piston crank type compressor and the hydraulic compressor and compress both low-pressure hydrogen and high-pressure hydrogen. Furthermore, sharing of an electric motor means that instead of providing separate electric motors for the piston crank compressor and the diaphragm compressor, a single electric motor is provided to drive both the piston crank compressor and the diaphragm compressor and perform low-pressure hydrogen compression and high-pressure hydrogen compression.

[0051] A specific structure in the case where the electric motor is shared will be described with reference to Figs. As shown in FIGS. 6 and 7, a motor pulley 102 is provided on a drive shaft 101 of an electric motor 100, and the motor pulley 102 can also rotate with the rotation of the drive shaft.

[0052] The electric motor pulley 102 and the low-pressure hydrogen compressor pulley (piston crank type compressor pulley) 103 are connected via a low-pressure hydrogen compressor belt (piston crank type compressor belt) 104, and the low-pressure hydrogen compressor pulley 103 is connected to a low-pressure hydrogen compressor side drive shaft (piston crank type compressor side drive shaft) 107.

[0053] In addition, the electric motor pulley 102 and the high-pressure hydrogen compressor pulley (hydraulic compressor pulley) 105 are connected via a high-pressure hydrogen compressor belt (hydraulic compressor belt) 106, and a high-pressure hydrogen compressor side drive shaft (hydraulic compressor side drive shaft) 108 is connected to the high-pressure hydrogen compressor pulley 105.

[0054] The crank piston type compressor 1 is configured to be driven by the rotation of a low-pressure hydrogen compressor side drive shaft 107.

[0055] The hydraulic compressor 2 is configured such that, when the high-pressure hydrogen compressor side drive shaft 108 is rotationally driven, a gear 172 (see Figure 4) connected to the high-pressure hydrogen compressor side drive shaft 108 is rotationally driven, thereby pressurizing the oil working fluid.

[0056] In this embodiment, the high-pressure hydrogen compressor 2 can be a diaphragm compressor instead of a hydraulic compressor. In this case, the piston rod 13 (see FIG. 5) is connected to a drive shaft 108 on the high-pressure hydrogen compressor side, and the rotational drive of the drive shaft 108 on the high-pressure hydrogen compressor side is converted into reciprocating motion of the piston rod to drive the diaphragm 18 (see FIG. 5).

[0057] In the illustrated example, the low-pressure hydrogen compressor 1 performs four-stage compression, but in this embodiment, although not shown, a return pipe for adjusting the hydrogen gas flow rate from each stage of the low-pressure hydrogen compressor 1 can also be provided. The high-pressure hydrogen compressor 2 can also be provided with a return pipe for adjusting the hydrogen gas flow rate.

[0058] In the illustrated example, the low-pressure hydrogen compressor 1 performs four-stage compression, but in this embodiment, although not shown, a return pipe for adjusting the hydrogen gas flow rate from each stage of the low-pressure hydrogen compressor 1 can also be provided. The high-pressure hydrogen compressor 2 can also be provided with a return pipe for adjusting the hydrogen gas flow rate.

[0059] The high-pressure hydrogen compressor side drive shaft 108 is provided with a clutch 109 that enables disconnection of the driving force of the electric motor 100. In other words, the driving force of the electric motor 100 can be ON-OFF controlled by the clutch 109.

[0060] The hydrogen passes through low-pressure compression in the low-pressure hydrogen compressor 1 and reaches a piping system 110 on the suction side of the high-pressure hydrogen compressor 2 . In this embodiment, a branch piping system 111 is provided that bypasses the high-pressure hydrogen compressor 2 and reaches the discharge side of the high-pressure hydrogen compressor 2 without entering the suction side of the high-pressure hydrogen compressor 2 via the low-pressure compression of the low-pressure hydrogen compressor 1. The branch piping system 111 is provided with a control valve 112 that controls opening and closing.

[0061] A pressure sensor 113 is provided near the hydrogen gas discharge portion of the compressor so as to be able to detect the discharge pressure.

[0062] FIG. 6 shows a state in which clutch 109 is engaged. When electric motor 100 drives, drive shaft 101 rotates. The rotation of drive shaft 101 rotates drive shaft 107 on the low-pressure hydrogen compressor side, and is converted into linear reciprocating motion of the piston via the crankshaft, compressing the hydrogen gas filled above the piston in the cylinder. At this time, since the control valve 112 provided in the branch piping system 111 is closed, the hydrogen gas compressed by the low-pressure hydrogen compressor 1 is introduced into the piping system 110 leading to the high-pressure hydrogen compressor 2 . Since the high-pressure hydrogen compressor 2 is connected to a clutch 109, the rotation of the drive shaft 101 of the electric motor 100 can rotate the high-pressure hydrogen compressor side drive shaft 108, thereby discharging the high-pressure hydrogen gas compressed by the high-pressure hydrogen compressor 2.

[0063] FIG. 7 shows the state in which the clutch 109 is disengaged. When the electric motor 100 is driven, the drive shaft 101 is rotated. The rotation of the drive shaft 101 rotates the low-pressure hydrogen compressor side drive shaft 107, which is converted into linear reciprocating motion of the piston via the crankshaft, compressing the hydrogen gas filled above the piston in the cylinder. At this time, since the control valve 112 provided in the branch piping system 111 is opened, the hydrogen gas compressed by the low-pressure hydrogen compressor 1 does not enter the piping system 110 leading to the high-pressure hydrogen compressor 2, but bypasses the high-pressure hydrogen compressor 2 and is introduced into the branch piping system 111, and reaches the line on the discharge side of the high-pressure hydrogen compressor 2. In this manner, the low-pressure hydrogen gas compressed by the low-pressure hydrogen compressor 1 can be discharged without starting the high-pressure hydrogen compressor 2.

[0064] As described above, the electric motor 100 can be shared by both the low-pressure hydrogen compressor 1 and the high-pressure hydrogen compressor 2. This eliminates the need for an electric motor in each compressor, thereby reducing installation space and simplifying control, thereby reducing the control panel and electrical / control wiring.

[0065] In addition, a clutch 109 is provided on the high-pressure hydrogen compressor side drive shaft 108 connected to the shared electric motor 100. When there is no need to drive the high-pressure hydrogen compressor 2, the connection with the electric motor 100 can be disconnected by the clutch 109, so that the high-pressure hydrogen compressor 2 cannot be driven. This shortens the actual operating time of the high-pressure hydrogen compressor 2, and therefore the maintenance interval for the high-pressure hydrogen compressor 2 can be extended. As a result, the useful life of the high-pressure hydrogen compressor 2 is extended, and the useful life of the entire compressor can be extended to the same extent as the useful life of the low-pressure hydrogen compressor 1.

[0066] In addition, it is possible to share auxiliary equipment, including the cooling fans that cool the refrigerant used to cool the hydrogen gas used in the two types of compressors, making it possible to significantly reduce the installation space.

[0067] In the examples of FIGS. 6 and 7, the low-pressure hydrogen compressor 1 performs four-stage compression, and the high-pressure hydrogen compressor 2 performs one-stage compression, but the present invention is not limited to this. Although not shown, a mechanism has been constructed that allows the hydrogen gas compressed at each stage to exchange heat with a refrigerant for cooling, and a mechanism has been constructed that aggregates the refrigerant so that it is cooled by a single cooling fan (not shown).As a result, one cooling fan is shared by both the low-pressure hydrogen compressor 1 and the high-pressure hydrogen compressor 2, greatly reducing the installation space.

[0068] In this way, it is possible to significantly reduce the installation space, making it possible to create a compressor unit that fits into a 20-ft container.

[0069] The control flow of the system of this embodiment will be described with reference to Fig. 8. Here, the explanation will be given using an example of hydrogen supply by the direct filling method shown in Fig. 1.

[0070] First, when the dispenser is connected to a hydrogen storage tank of a mobile object, the required pressure of the hydrogen storage tank is detected (S1).

[0071] Next, it is determined whether the required pressure exceeds a predetermined set value (S2), where the predetermined set value is a pressure that has been set in advance.

[0072] In this embodiment, an example will be described in which hydrogen is compressed in a total of five stages, for example, using a four-stage low-pressure hydrogen compressor and one-stage high-pressure hydrogen compressor. In this case, if the high pressure discharge pressure is 90MPa and the suction pressure is 3MPa, a 30-fold boost is required to boost 3MPa to 90MPa. If the 30-fold boost is achieved in five stages, and each stage is boosted at the same pressure, the boost is 1.98 times per stage.

[0073] When the suction pressure is 3 MPa and the pressure is increased at a constant rate of 1.98 times, the first stage discharge pressure is approximately 5.9 MPa, the second stage discharge pressure is approximately 11.6 MPa, the third stage discharge pressure is approximately 22.9 MPa, the fourth stage discharge pressure is approximately 45.2 MPa, and the fifth stage discharge pressure is approximately 90 MPa.

[0074] In this way, by determining the suction pressure and the target discharge pressure at the design stage, the pressure boost ratio at each stage can be determined at the design stage. Therefore, by setting the set pressure to a value equal to or close to the discharge pressure of the final stage of the low-pressure hydrogen compressor 1 in the determined multiple stages, it is possible to determine whether or not to compress the hydrogen using the high-pressure hydrogen compressor 2 described below in relation to the required pressure (necessary pressure) of the supply destination of the compressor.

[0075] If the required pressure is equal to or lower than the predetermined set value (NO in S2), the required pressure is lower than the set value (set pressure), so the clutch 109 of the high-pressure hydrogen compressor 2 is disengaged (clutch open) (S3), the control valve 112 is opened (S4), the electric motor 100 is started, and the compressor is started (S7). In this case, since the clutch 109 is disengaged, only the low-pressure hydrogen compressor 1 is started, and the high-pressure hydrogen compressor 2 is not started.

[0076] On the other hand, if the required pressure is greater than the predetermined set value (YES in S2), the required pressure is higher than the set value (set pressure), so the clutch 109 of the high-pressure hydrogen compressor 2 is connected (clutch closed) (S5), the control valve 112 is closed (S6), the electric motor 100 is started, and the compressor is started (S7). In this case, because the clutch 109 is connected, both the low-pressure hydrogen compressor 1 and the high-pressure hydrogen compressor 2 are started.

[0077] Next, when a predetermined condition for transmitting a stop signal is satisfied, a stop signal process is performed to transmit a stop signal (S8). The predetermined condition for the stop signal processing may be, for example, pressing an emergency stop button, completion of hydrogen supply, etc. In addition, a mechanical failure or the like may be detected, but is not limited to these, and is preferably determined taking safety and reliability into consideration.

[0078] Next, it is determined whether or not a stop signal is present (S9). If a stop signal is present, operation of the compressor is stopped (S10). If no stop signal is present, the process returns to detecting the required pressure (S1) and continues processing until a stop signal is present.

[0079] The above-described embodiment is merely an example, and is not intended to limit the scope of the invention. The invention can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. Such embodiments and modifications are within the scope and spirit of the invention, and are included in the scope of the invention and its equivalents as set forth in the claims. [Explanation of symbols]

[0080] 1: Low pressure hydrogen compressor 2: High pressure hydrogen compressor 3: Dispenser 4: Moving object 5: Pressure accumulator 10: Cylinder 11: Piston 12: Piston rings 13: Piston rod 14:Joining rod 15: Crankshaft 16: Piston seal 17: Oil hydraulic fluid 18: Diaphragm 100: Electric motor 101: Drive shaft 102: Electric motor pulley 103: Pulley for low pressure hydrogen compressor (Pulley for piston crank type compressor) 104: Belt for low pressure hydrogen compressor (belt for piston crank compressor) 105: Pulley for high pressure hydrogen compressor (pulley for hydraulic compressor) 106: High pressure hydrogen compressor belt (hydraulic compressor belt) 107: Low pressure hydrogen compressor drive shaft (piston crank compressor drive shaft) 108: High pressure hydrogen compressor drive shaft (hydraulic compressor drive shaft) 109: Clutch 110: Piping system 111: Branch piping system 112: Control valve 113: Pressure sensor

Claims

1. Equipped with a low-pressure compressor and a high-pressure compressor to compress hydrogen gas, A method for supplying hydrogen gas to a destination in accordance with a required pressure, the required pressure of which has a low pressure region and a high pressure region, the low-pressure compressor is a piston crank compressor, The high-pressure compressor is a hydraulic compressor or a diaphragm compressor, When the required pressure of the supply destination is in a low pressure region, the hydrogen gas compressed by the low pressure compressor is supplied to the supply destination; A method for supplying hydrogen gas, characterized in that, when the required pressure of the supply destination is in the high pressure region, hydrogen gas is compressed by the low pressure compressor, the compressed hydrogen gas is introduced into the high pressure compressor, and the hydrogen gas compressed by the high pressure compressor is supplied to the supply destination.

2. 2. The method for supplying hydrogen gas according to claim 1, wherein the supply destination of the hydrogen gas is a pressure accumulator at a hydrogen station or a hydrogen storage tank of a mobile body.

3. 3. The method for supplying hydrogen gas according to claim 2, characterized in that the method of filling the hydrogen storage tank is a direct filling method from the low-pressure compressor and the high-pressure compressor, a differential pressure filling method from the accumulator, or a combination of the direct filling method and the differential pressure filling method.

4. 2. The method for supplying hydrogen gas according to claim 1, wherein the low-pressure region of the required pressure at the supply destination is a region having an upper limit value of any value between 40 and 50 MPa, and the high-pressure region is a region greater than the upper limit value of the low-pressure region and not exceeding 100 MPa.

5. 2. The method for supplying hydrogen gas according to claim 1, wherein the piston crank type compressor and the hydraulic compressor or the diaphragm type compressor share a common electric motor.

6. 6. The method for supplying hydrogen gas according to claim 5, further comprising providing a clutch for controlling ON / OFF of the drive of the hydraulic compressor or the diaphragm compressor.

7. 2. The hydrogen gas supply method according to claim 1, characterized in that the piston crank type compressor and the hydraulic compressor or diaphragm type compressor are mounted together, and common auxiliary equipment is shared to form a unit of a size that can fit on the same skid.

8. The flow rate of hydrogen gas that can be supplied to the supply destination is 400 Nm ３ / Hr~1200Nm ３ 2. The method for supplying hydrogen gas according to claim 1, wherein the hydrogen gas supply rate is 1 / Hr.

9. Equipped with a low-pressure compressor and a high-pressure compressor to compress hydrogen gas, A hydrogen gas supply system in which the required pressure of a supply destination has a low pressure region and a high pressure region, and the hydrogen gas supply system supplies the hydrogen gas to the supply destination in accordance with the required pressure, the low-pressure compressor is a piston crank compressor, The high-pressure compressor is a hydraulic compressor or a diaphragm compressor, When the required pressure of the supply destination is in the low pressure region, the hydrogen gas compressed by the low pressure compressor is supplied to the supply destination; A hydrogen gas supply system characterized by compressing hydrogen gas by the low-pressure compressor when the required pressure of the supply destination is in the high-pressure region, introducing the compressed hydrogen gas into the high-pressure compressor, and supplying the hydrogen gas compressed by the high-pressure compressor to the supply destination.

10. 10. The hydrogen gas supply system according to claim 9, wherein the hydrogen gas is supplied to a pressure accumulator at a hydrogen station or a hydrogen storage tank of a mobile body.

11. 11. The hydrogen gas supply system according to claim 10, characterized in that the method of filling the hydrogen storage tank is a direct filling method from the low-pressure compressor and the high-pressure compressor, a differential pressure filling method via the accumulator, or a combination of the direct filling method and the differential pressure filling method.

12. The hydrogen gas supply system of claim 9, characterized in that the low pressure region of the required pressure at the destination is a region where the upper limit value is any value between 40 and 50 MPa, and the high pressure region is a region that is greater than any value of the upper limit value of the low pressure region and is not greater than 100 MPa.

13. 10. The hydrogen gas supply system according to claim 9, wherein the piston crank compressor and the hydraulic compressor or the diaphragm compressor share a common electric motor.

14. 14. The hydrogen gas supply system according to claim 13, further comprising a clutch for controlling ON / OFF of the drive of the hydraulic compressor or the diaphragm compressor.

15. 10. The hydrogen gas supply system as described in claim 9, characterized in that the piston crank type compressor and the hydraulic compressor or diaphragm type compressor are mounted together and common auxiliary equipment is shared, forming a compressor unit of a size that can fit on the same skid.

16. The flow rate of hydrogen gas that can be supplied to the supply destination is 400 Nm ３ / Hr~1200Nm ３ 10. The hydrogen gas supply system according to claim 9, wherein the hydrogen gas supply rate is 100 / Hr.

17. A motor pulley (102) provided on a drive shaft (101) of the electric motor (100); A piston crank compressor pulley (103) provided on a piston crank compressor side drive shaft (107) of the piston crank compressor (1); a hydraulic compressor pulley (105) provided on a hydraulic compressor side drive shaft (108) of the hydraulic compressor (2), The motor pulley (102) and the piston crank compressor pulley (103) are rotatably connected to each other via a piston crank compressor belt (104), The electric motor pulley (102) and the hydraulic compressor pulley (105) are rotatably connected via a hydraulic compressor belt (106), The piston crank compressor (1) has a structure in which the rotation of a drive shaft by the drive of an electric motor is converted into linear reciprocating motion of a piston via a crankshaft, and compresses hydrogen gas filled above the piston in a cylinder. The hydraulic compressor (2) is configured such that the rotation of the drive shaft by the drive of an electric motor is converted into reciprocating motion of a piston by the hydraulic pressure generated by driving a hydraulic pump, and the reciprocating motion of the piston compresses the hydrogen gas filled in the cylinder.

18. a piping system (110) that leads to the suction side of the hydraulic compressor (2) that compresses high pressure hydrogen via the low pressure compression of the piston crank compressor (1) and leads to the hydraulic compressor (2); and a branch piping system (111) that leads to the discharge side of the hydraulic compressor (2) by bypassing the hydraulic compressor (2) via the piston crank compressor (1) without entering the suction side of the hydraulic compressor (2), A control valve (112) for controlling opening and closing is provided in the branch piping system (111); a clutch (109) for disconnecting the driving force of the electric motor (105) of the hydraulic compressor (2) from the drive shaft (108) of the hydraulic compressor (2); When the required pressure of the supply destination is equal to or lower than the set value, the clutch (109) is disengaged and the control valve (112) is opened; 10. The hydrogen gas supply system according to claim 9, wherein when the required pressure of the supply destination becomes greater than the set value, the clutch (109) is connected and the control valve (112) is closed.

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