Discharge valve, booster pump and hydrogen supply system

Abstract

To improve workability of a valve body and inhibit damage of the valve body in a discharge valve and a booster pump and a hydrogen supply system.SOLUTION: A discharge valve includes: a casing in which a fluid inflow hole and a fluid discharge hole communicate with each other and which has a storage space part communicating with the fluid discharge hole; a valve seat disposed in the storage space part and having an inflow port communicating with the fluid inflow hole and a discharge port communicating with the fluid discharge hole; a valve body supported in a manner that the valve body may move to a close position where the valve body closes the inflow port at the storage space part and an open position where the valve body opens the inflow port; and a first communication part which allows communication between an arrangement space part, which is located at the opposite side of the inflow port with respect to the valve body in the storage space part, and the fluid discharge hole.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a discharge valve of a booster pump that boosts the pressure of a cryogenic fluid such as liquid hydrogen, a booster pump having a discharge valve, and a hydrogen supply system having a booster pump. [Background technology]

[0002] An example of a discharge valve for a conventional booster pump is described in Patent Document 1 below. The discharge valve described in Patent Document 1 includes a valve seat having an inlet hole and a discharge hole, a valve element that can open and close the inlet hole, a valve seat pressing member that positions the valve seat, and a spring member that urges the valve element against the valve seat in a direction that closes the inlet hole. With this discharge valve, when the pressure of the fluid acting on the compression chamber exceeds the sum of the pressures inside the discharge valve, the valve element begins to move, opening the inlet hole and allowing the fluid that has flowed in from the inlet hole to be discharged from the discharge hole. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 1041807 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional discharge valves, a spring member is placed in the space between the valve disc and the valve seat pressing member. When high-pressure fluid causes the valve disc to move backward against the biasing force of the spring member, the volume of the space decreases and the pressure increases. This causes the fluid in the space to flow through the outer periphery of the valve disc and into the discharge hole. At this time, the direction of the fluid flow from the space to the discharge hole is opposite to the direction in which the valve disc moves backward, which creates a problem of impeding the backward movement of the valve disc. Furthermore, when the fluid flows from the space to the discharge hole at high speed, cavitation erosion occurs, which can damage the valve disc.

[0005] The present disclosure is devised to solve the above-mentioned problems, and aims to provide a discharge valve, a booster pump, and a hydrogen supply system that improve the operability of the valve body and suppress damage to the valve body. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the discharge valve of the present disclosure comprises a casing having a storage space portion in which a fluid inlet and a fluid discharge hole are respectively connected and in which the fluid discharge hole is connected; a valve seat disposed in the storage space portion and having an inlet communicating with the fluid inlet and an outlet communicating with the fluid discharge hole; a valve body supported in the storage space portion so as to be movable between a closed position that closes the inlet and an open position that opens the inlet; and a first communication portion that communicates the fluid discharge hole with an arrangement space portion on the opposite side of the valve body from the inlet in the storage space portion.

[0007] The boost pump of the present disclosure also includes an intake valve that draws low-temperature fluid into a compression chamber, a piston that compresses the low-temperature fluid drawn into the compression chamber from the intake valve, and a discharge valve that discharges the low-temperature fluid compressed by the piston.

[0008] The hydrogen supply system of the present disclosure also includes a compressor having the boost pump and compressing liquid hydrogen as a cryogenic fluid, an evaporator that vaporizes the liquid hydrogen compressed by the compressor, and a dispenser that supplies the hydrogen gas vaporized by the evaporator. [Effects of the Invention]

[0009] According to the discharge valve, booster pump, and hydrogen supply system of the present disclosure, it is possible to improve the operability of the valve element and to suppress damage to the valve element. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing the overall configuration of a hydrogen supply system according to the first embodiment. [Figure 2]FIG. 2 is a schematic diagram showing the configuration of the compression device. [Figure 3] FIG. 3 is a vertical cross-sectional view showing a main part of a booster pump including a discharge valve of the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 5 is a vertical cross-sectional view showing the boost pump in operation. [Figure 6] FIG. 6 is a cross-sectional view illustrating the discharge valve of the first embodiment. [Figure 7] FIG. 7 is a cross-sectional view illustrating a discharge valve according to the second embodiment. [Figure 8] FIG. 8 is a cross-sectional view illustrating a discharge valve according to the third embodiment. [Figure 9] FIG. 9 is a cross-sectional view illustrating a discharge valve according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Preferred embodiments of the present disclosure will be described in detail below with reference to the drawings. Note that the present disclosure is not limited to these embodiments, and when there are multiple embodiments, the present disclosure also includes configurations that combine the embodiments. Furthermore, the components in the embodiments include those that can be easily imagined by a person skilled in the art, those that are substantially identical, and those that are within the so-called equivalent range.

[0012] [First embodiment] <Hydrogen supply system> FIG. 1 is a schematic diagram showing the overall configuration of a hydrogen supply system according to the first embodiment.

[0013] As shown in Fig. 1, a hydrogen supply system 10 supplies (replenishes) liquid hydrogen stored in a container 11 as hydrogen gas at a predetermined pressure to a power source of a vehicle 12. Here, the power source is, for example, a fuel cell or a hydrogen engine, and is mounted on the vehicle 12. The hydrogen supply system 10 is, for example, a so-called hydrogen filling station facility that supplies (replenishes) hydrogen gas, which is a fuel, to the power source of the vehicle 12. However, the hydrogen supply system 10 is not limited to supplying hydrogen gas to the power source of the vehicle 12, but may also compress and supply a cryogenic fluid (for example, liquid hydrogen, liquid nitrogen, liquid oxygen, liquefied carbon dioxide, liquefied natural gas, liquefied propane gas, etc.).

[0014] The hydrogen supply system 10 includes a compressor 21, an evaporator 22, and a dispenser 23. The compressor 21 compresses liquid hydrogen (low-temperature fluid) supplied from the container 11 to a predetermined high pressure (high-pressure state). The evaporator 22 generates hydrogen gas by vaporizing the high-pressure liquid hydrogen compressed by the compressor 21. The dispenser 23 fills the hydrogen gas generated by the evaporator 22 into the power source of the vehicle 12.

[0015] Although the compressor 21 compresses the liquid hydrogen stored in the container 11 to a predetermined high pressure, the configuration is not limited to this. For example, if the container 11 stores hydrogen gas, the compressor 21 may compress the hydrogen gas stored in the container 11 to a predetermined high pressure.

[0016] The compressor 21 has a drive motor 31 and a boost pump 32. The drive motor 31 is an electric motor that can be driven by power supplied from an external source. The rotation speed of the drive motor 31 is controlled by an inverter (not shown). The drive motor 31 transmits the rotational force to the boost pump 32. The boost pump 32 is operated by the rotational force of the drive motor 31.

[0017] <Compression device> FIG. 2 is a schematic diagram showing the configuration of the compression device.

[0018] As shown in Figure 2, the drive motor 31 is connected to the boost pump 32 via a reducer 33. The reducer 33 reduces the rotational force of the drive motor 31 and transmits it to the boost pump 32. The boost pump 32 is a reciprocating pump. The boost pump 32 operates by converting the rotational force of the drive motor 31, which has been reduced in speed by the reducer 33, into reciprocating power. The boost pump 32 uses the reciprocating power to alternately draw in and compress (boost) liquid hydrogen, compressing the drawn-in liquid hydrogen to a predetermined high-pressure state and discharging it to the outside.

[0019] The booster pump 32 includes a crank mechanism 34 , a crosshead 35 , a piston rod 36 , a piston 37 , and a cylinder block 38 .

[0020] The crank mechanism 34 converts the rotational force transmitted from the reducer 33 into linear reciprocating power and transmits it to the crosshead 35. The crosshead 35 reciprocates in the vertical direction VD due to the reciprocating power in the vertical direction VD transmitted from the crank mechanism 34. The upper end of the piston rod 36 is connected to the crosshead 35, and the other end is connected to a piston 37. The cylinder block 38 has a hollow shape, and the piston 37 is supported therein so as to be movable along the vertical direction VD.

[0021] The lower part of the boost pump 32, i.e., the cylinder block 38, is disposed inside the vessel 39. The vessel 39 is an insulated vacuum vessel, and the inside thereof is maintained in a vacuum state together with the boost pump 32. Liquid hydrogen is supplied to the inside of the vessel 39, and the vessel 39 is filled to atmospheric pressure.

[0022] When the boost pump 32 is activated, first, during the suction stroke when the piston 37 rises, liquid hydrogen in the container 39 is sucked into the cylinder block 38. Next, during the compression stroke when the piston 37 descends, the liquid hydrogen inside the cylinder block 38 is compressed, and high-pressure liquid hydrogen is discharged outside the container 39.

[0023] <Booster pump configuration> FIG. 3 is a vertical cross-sectional view showing a main part of a booster pump including a discharge valve of the first embodiment, and FIG. 4 is a cross-sectional view taken along line IV-IV in FIG.

[0024] 3, boost pump 32 includes a suction valve 41 and a discharge valve 42. When opened, suction valve 41 draws liquid hydrogen into compression chamber 43. When opened, discharge valve 42 discharges high-pressure liquid hydrogen compressed in compression chamber 43 to the outside.

[0025] The cylinder block 38 is disposed along the vertical direction VD. The cylinder block 38 has a fitting hole 51 that opens upward formed in its upper part, and a recess 52 that opens downward formed in its lower part. The fitting hole 51 and the recess 52 are cylindrical and communicate with each other through a communication hole 53 that is also cylindrical. The piston 37 fits into the fitting hole 51 of the cylinder block 38 from above and is supported so as to be movable along the vertical direction VD. When the piston 37 fits into the fitting hole 51 of the cylinder block 38, a compression chamber 43 is formed, which is defined by the piston 37 and the fitting hole 51. The fitting hole 51, the recess 52, the communication hole 53, the piston 37, and the compression chamber 43 are concentrically disposed.

[0026] 3 and 4, the suction valve 41 is disposed in the recess 52 of the cylinder block 38. The suction valve 41 has a valve casing 61, a first valve body 62, a second valve body 63, and a pressing member 64.

[0027] The valve casing 61 has a convex cylindrical shape. The valve casing 61 has a small-diameter main body portion 61a and a flange portion 61b with a diameter larger than that of the main body portion 61a. The valve casing 61 is configured such that the flange portion 61b is integrally formed with the lower part of the main body portion 61a. The recess 52 has a small-diameter hole 52a and a large-diameter hole 52b with a diameter larger than that of the small-diameter hole 52a. The recess 52 is configured such that the large-diameter hole 52b is integrally formed with the lower part of the small-diameter hole 52a. The main body portion 61a of the valve casing 61 is fitted into the small-diameter hole 52a of the recess 52, and the flange portion 61b is fitted into the large-diameter hole 52b of the recess 52. In this state, the lower surface of the flange portion 61b of the valve casing 61 is continuous with the lower surface of the cylinder block 38 without any step. The length of the main body 61a of the valve casing 61 is shorter than the length of the small-diameter hole 52a, so that the tip surface of the main body 61a and the bottom surface of the small-diameter hole 52a face each other with a gap between them, thereby defining a space 71 between the recess 52 of the cylinder block 38 and the valve casing 61.

[0028] The valve casing 61 has a through hole 72 formed in the center along the vertical direction VD. The valve casing 61 also has a plurality of (six in this embodiment) suction holes 73 formed along the vertical direction VD at intervals in the circumferential direction on the radially outer peripheral side. The valve casing 61 also has a plurality of (eight in this embodiment) discharge holes 74 formed along the vertical direction VD at intervals in the circumferential direction on the radially outer side of the through hole 72. The suction holes 73 draw liquid hydrogen from the outside into the space 71. The discharge holes 74 discharge liquid hydrogen or hydrogen gas remaining in the space 71 to the outside. The outside refers to the outside of the cylinder block 38, container 39 (See Figure 2) and is filled with liquid hydrogen at a low pressure of between atmospheric pressure and 1 MPaG.

[0029] The first valve body 62 has a rod portion 62a and a head portion 62b. The first valve body 62 has a head portion 62b integrally provided at the upper end of the rod portion 62a. The rod portion 62a is arranged inside the valve casing 61 along the vertical direction VD. That is, the rod portion 62a of the first valve body 62 is fitted into a through-hole 72 of the valve casing 61, and the first valve body 62 is supported so as to be movable along the axial direction (vertical direction VD). The head portion 62b has a generally truncated conical shape whose diameter increases upward. The flat upper surface of the head portion 62b of the first valve body 62 is a pressure-receiving surface 62c, and the curved lower surface of the head portion 62b is a seat surface 62d. The pressure-receiving surface 62c of the first valve body 62 faces the compression chamber 43.

[0030] Meanwhile, the cylinder block 38 has a diameter that expands upward so that the upper portion of the communication hole 53 has the same shape as the head portion 62b, and is provided with a valve seat 53a. The head portion 62b of the first valve body 62 is disposed above the communication hole 53, and the seat surface 62d can seat on the valve seat 53a. When the first valve body 62 moves downward and the seat surface 62d of the head portion 62b seats on the valve seat 53a, it closes the communication hole 53 and blocks communication between the compression chamber 43 and the space 71. When the first valve body 62 moves upward and the seat surface 62d of the head portion 62b moves away from the valve seat 53a, it opens the communication hole 53 and connects the compression chamber 43 and the space 71.

[0031] Furthermore, the lower end of the rod portion 62a of the first valve body 62 protrudes downward from the valve casing 61. A spring receiving member 76 is fixed to the lower end of the rod portion 62a by a nut 75. A compression coil spring 77 serving as a biasing member is disposed between a spring receiving portion 61c formed on the valve casing 61 and the spring receiving member 76 of the first valve body 62. The compression coil spring 77 biases the first valve body 62 downward with respect to the valve casing 61. That is, the biasing force of the compression coil spring 77 biases the first valve body 62 in a direction in which the seat surface 62d of the head portion 62b seats on the valve seat 53a of the communication hole 53, and the first valve body 62 is biased and supported in a position in which the communication hole 53 is closed and the compression chamber 43 is isolated from the space 71.

[0032] The second valve body 63 is a disk-shaped plate-like member with an opening 63a at its center. The second valve body 63 has an outer diameter approximately equal to that of the valve casing 61 and an inner diameter larger than the diameter of the positions where the multiple discharge holes 74 are formed. The second valve body 63 is disposed in a space 71 defined between the recess 52 of the cylinder block 38 and the valve casing 61. The second valve body 63 is supported in the space 71 so as to be movable in the vertical direction VD relative to the cylinder block 38 and the valve casing 61. Ring-shaped seal members 81 and 82 are disposed between the second valve body 63 and the main body 61a of the valve casing 61. The seal member 81 is disposed on the outer periphery of the main body 61a, and the seal member 82 is disposed on the inner periphery of the main body 61a. That is, the seal members 81 and 82 are disposed on both radial sides of the main body 61a, sandwiching the multiple suction holes 73 therebetween. The second valve body 63 has a pressure-receiving surface 63b on its upper surface and a seat surface 63c on its lower surface that contacts the seal members 81 and 82. The pressure-receiving surface 63b of the second valve body 63 faces the communication hole 53. When the seat surface 63c of the second valve body 63 is seated on the seal members 81 and 82, the space 71 is blocked from communicating with the plurality of suction holes 73. On the other hand, when the seat surface 63c of the second valve body 63 is separated from the seal members 81 and 82, the space 71 is communicated with the plurality of suction holes 73.

[0033] The pressing member 64 has a cylindrical shape. The pressing member 64 presses the valve casing 61 against the cylinder block 38. That is, the pressing member 64 has a plurality of mounting holes (not shown) aligned along the vertical direction VD and spaced apart in the circumferential direction. The upper surface of the pressing member 64 contacts the lower surface of the cylinder block 38 and the lower surface of the flange portion 61b of the valve casing 61. In this state, a plurality of fastening bolts 91 are inserted from below into the mounting holes of the pressing member 64, and their tip ends are threaded into threaded holes (not shown) in the cylinder block 38. By fastening the pressing member 64 to the cylinder block 38, the valve casing 61 is positioned in the recess 52 and is pressed against the pressing member 64, and is supported by the cylinder block 38.

[0034] The pressing member 64 has an outer diameter that is approximately the same as the outer diameter of the cylinder block 38, and an inner diameter that is larger than the diameter at the positions where the multiple suction holes 73 are formed. Therefore, the lower end openings of the multiple suction holes 73 and the lower end openings of the multiple discharge holes 74 are exposed inside the pressing member 64. The multiple suction pipes 92 are supported by the pressing member 64 via a support member (not shown). One end of the multiple suction pipes 92 is connected to the lower end openings of the multiple suction holes 73, and the other end extends upward and opens to the outside, i.e., into the interior of the container 39 (see FIG. 2).

[0035] The discharge valve 42 is a check valve and is disposed on the side of the cylinder block 38. The discharge valve 42 is accommodated in an accommodation hole (accommodation space) 151 formed in the cylinder block 38. The accommodation hole 151 is formed along a radial direction (horizontal direction HD) perpendicular to the axial direction (vertical direction VD) of the cylinder block 38. The accommodation hole 151 has an opening 152 that opens to the outside on one side in the horizontal direction HD. The discharge valve 42 is inserted into the accommodation hole 151 from the opening 152 and positioned, and the opening 152 is closed by a closing member 153.

[0036] The cylinder block 38 is formed with an inlet hole 154 communicating with the compression chamber 43 on the other side of the horizontal direction HD relative to the discharge valve 42, and a ring-shaped annular flow passage 155 is formed on the outer periphery of the discharge valve 42. The annular flow passage 155 is connected to a discharge hole (not shown) for hydrogen gas.

[0037] The discharge valve 42 has a valve seat 101, a valve element 102, a valve seat pressing member 103, and a compression coil spring (biasing member) 104. The valve element 102 has a ball 111 and a support member 112. The valve seat 101 is The valve body 102 has an inlet 113 communicating with the inlet hole 154 and a discharge port 114 communicating with the annular flow path 155. The ball 111 of the valve body 102 closes the inlet 113 by the biasing force of the compression coil spring 104.

[0038] When high-pressure liquid hydrogen from compression chamber 43 acts on inlet 113 through inlet 154, valve element 102 moves backward against the biasing force of compression coil spring 104, opening inlet 113. Then, the liquid hydrogen in compression chamber 43 flows from inlet 154 through inlet 113 into discharge valve 42 and is discharged from discharge port 114 to annular flow path 155.

[0039] <Booster pump operation> FIG. 5 is a vertical cross-sectional view showing the boost pump in operation.

[0040] As shown in FIG. 5 , first, during the suction stroke of the boost pump 32, when the piston 37 moves (rises) from the bottom dead center to the top dead center via the piston rod 36, the volume of the compression chamber 43 expands, causing the pressure in the compression chamber 43 to become negative. At this time, the upward force (suction force) of the first valve body 62 overcomes the biasing force of the compression coil spring 77, causing the seat surface 62d of the head portion 62b to move away from the valve seat 53a. The first valve body 62 then opens the communication hole 53, thereby connecting the compression chamber 43 to the space 71. Furthermore, when the negative pressure in the compression chamber 43 acts on the second valve body 63 through the communication hole 53, the second valve body 63 moves upward due to the negative pressure, and the seat surface 63c moves away from the seal members 81 and 82. The second valve body 63 then connects the space 71 to each suction hole 73. Therefore, the suction valve 41 draws external liquid hydrogen from each suction pipe 93 through each suction hole 73 into the space 71 , and further through the communication hole 53 into the compression chamber 43 .

[0041] As shown in FIG. 3 , during the compression stroke of the boost pump 32, when the piston 37 moves (descends) via the piston rod 36 to the top dead center or bottom dead center, the volume of the compression chamber 43 decreases, causing the pressure in the compression chamber 43 to become positive. At this time, the suction force of the first valve body 62 decreases, causing it to move downward due to the biasing force of the compression coil spring 77, and the seat surface 62d of the head portion 62b seats on the valve seat 53a. The first valve body 62 then closes the communication hole 53, blocking communication between the compression chamber 43 and the space 71. Furthermore, when the positive pressure in the compression chamber 43 acts on the second valve body 63 through the communication hole 53, the suction force of the second valve body 63 decreases, causing it to move downward, and the seat surface 63c seats on the seal members 81 and 82. The second valve body 63 then blocks communication between the space 71 and each suction hole 73.

[0042] As the piston 37 moves further downward, the volume of the compression chamber 43 is further reduced, causing the pressure in the compression chamber 43 to increase. At this time, when the pressure of the liquid hydrogen in the compression chamber 43 reaches or exceeds a predetermined high pressure, the pressure of the liquid hydrogen exceeds the biasing force of the compression coil spring 104, causing the valve element 102 to move backward and opening the inlet 113. The liquid hydrogen in the compression chamber 43 then flows from the inlet 154 through the inlet 113 into the discharge valve 42, is discharged from the discharge port 114 into the annular flow path 155, and is then discharged to the outside of the cylinder block 38 through the discharge hole.

[0043] During the compression stroke of booster pump 32, first valve body 62 descends and seat surface 62d of head portion 62b seats on valve seat 53a to close communication hole 53, during which time some of the high-pressure liquid hydrogen in compression chamber 43 leaks through communication hole 53 into space 71. The high-pressure liquid hydrogen that has leaked into space 71 is discharged through each discharge hole 74 into the interior of container 39 (see FIG. 2), which is at atmospheric pressure.

[0044] <Discharge valve configuration> Here, a detailed description will be given of the discharge valve 42. Fig. 6 is a cross-sectional view showing the discharge valve of the first embodiment.

[0045] As shown in FIG. 5, the discharge valve 42 is provided in a housing hole 151 formed in the cylinder block (casing) 38, and includes a valve seat 101, a valve body 102, a valve seat pressing member 103, a compression coil spring 104, and a first communication hole (first communication portion) 105.

[0046] The accommodating hole 151 has a cylindrical shape extending along the horizontal direction HD. The accommodating hole 151 has an opening 152 formed on one side in the horizontal direction HD (the right side in FIG. 5) and is closed by a closing member 153. The accommodating hole 151 also has an inlet hole 154 formed on the other side in the horizontal direction HD (the left side in FIG. 5). Furthermore, the accommodating hole 151 has an annular flow path 155 formed radially outward on the other side in the horizontal direction HD. The inlet hole 154 communicates with the compression chamber 43 (see FIG. 3), and the annular flow path 155 communicates with a discharge hole (not shown).

[0047] The valve seat 101 is cylindrical and is disposed inside the annular flow path 155 on the other side of the horizontal direction HD of the accommodating hole 151. The valve seat 101 is positioned in the axial and radial directions by having its end on the other side in the axial direction (horizontal direction HD) come into contact with the end face of the accommodating hole 151 and its outer circumferential surface on the other side in the horizontal direction HD come into contact with the inner circumferential surface of the accommodating hole 151. A ring-shaped seal member 121 is provided at the end on the other side in the axial direction (horizontal direction HD), and seals by coming into close contact with the end face of the accommodating hole 151 (cylinder block 38).

[0048] The valve seat 101 has an accommodating hole 101a formed along the axial direction, and the accommodating hole 101a opens to one side in the axial direction. The valve seat 101 also has an inlet 113 formed on the other side in the axial direction, and an outlet 114 formed radially outward. The inlet 113 is a hole formed along the axial direction at the center of the valve seat 101. The inlet 113 connects the inlet hole 154 and the accommodating hole 101a. The outlet ports 114 are holes formed along the radial direction of the valve seat 101, and are provided at intervals in the circumferential direction. The outlet ports 114 connect the annular flow path 155 and the accommodating hole 101a.

[0049] The valve body 102 has a ball 111 and a support body 112. The support body 112 is cylindrical and has a receiving portion 112a and a rod portion 112b. The receiving portion 112a has a hemispherical receiving surface 112c that receives the ball 111. The rod portion 112b is provided integrally with the receiving portion 112a on the side opposite to the receiving surface 112c. The outer diameter of the rod portion 112b of the support body 112 is smaller than the outer diameter of the receiving portion 112a, thereby forming a step portion 112d. The ball 111 fits into the receiving surface 112c of the support body 112 to form an integral body. Note that the ball 111 and the support body 112 of the valve body 102 may be separate or integral.

[0050] The valve element 102 is disposed in the accommodation hole 101a of the valve seat 101 and is supported so as to be movable in the axial direction. The valve element 102 is movable between a closed position where it closes the inlet 113 of the valve seat 101 and an open position where it opens the inlet 113. The closed position of the valve element 102 is a position (position shown in FIG. 5) where the ball 111 is seated in close contact with the periphery of the inlet 113 of the valve seat 101. The open position of the valve element 102 is a position (position moved to the right from the position shown in FIG. 5) where the ball 111 is separated from the inlet 113 of the valve seat 101.

[0051] The valve seat hold-down member 103 has a cylindrical shape with one axial end closed. The valve seat hold-down member 103 has a tubular portion 103a, a partition wall portion 103b, and a threaded portion 103c. The tubular portion 103a has an accommodating hole 103d formed along the axial direction. The partition wall portion 103b is integrally formed with the tubular portion 103a on one axial end, thereby closing the accommodating hole 103d, and the accommodating hole 103d is open on the other axial end. The threaded portion 103c is formed on the outer peripheral surface of the tubular portion 103a and screws into a threaded portion 151a formed on the inner peripheral surface of the accommodating hole 151.

[0052] That is, the valve seat hold-down member 103 is inserted into the accommodation hole 151 from the opening 152, and by rotating the valve seat hold-down member 103, the threaded portion 103c screws into the threaded portion 151a of the accommodation hole 151. When the valve seat hold-down member 103 is further rotated, the valve seat hold-down member 103 moves in the other axial direction and stops when its tip abuts against the valve seat 101. Therefore, the valve seat hold-down member 103 is fixed to the cylinder block 38 at the position where its tip abuts against the valve seat 101, and the valve seat 101 is also positioned and fixed to the cylinder block by the valve seat hold-down member 103.

[0053] At this time, the valve seat 101 and the valve seat hold-down member 103 come into contact, so that the accommodating hole 101a of the valve seat 101 and the accommodating hole 103d of the valve seat hold-down member 103 communicate with each other. Here, the inner diameter of the accommodating hole 101a of the valve seat 101 and the inner diameter of the accommodating hole 103d of the valve seat hold-down member 103 are the same. In other words, an arrangement space 115 is defined between the valve seat 101 and the valve seat hold-down member 103 by the accommodating holes 101a and 103d. The ball 111 of the valve element 102 is positioned in the accommodating hole 101a of the valve seat 101, and the support body 112 extends from the accommodating hole 101a of the valve seat 101 to the accommodating hole 103d of the valve seat hold-down member 103. The outer diameter of the receiving portion 112a of the support body 112 is slightly smaller than the inner diameter of the accommodating hole 101a of the valve seat 101. Furthermore, the support body 112 has a gap between the outer peripheral surface of the rod portion 112b and the inner peripheral surface of the accommodation hole 103d of the valve seat pressing member 103, through which the compression coil spring 104 is interposed.

[0054] The compression coil spring 104 is disposed in the arrangement space 115 on the opposite side of the inlet 113 with respect to the valve element 102, i.e., between the valve element 102 and the valve seat hold-down member 103. At this time, the compression coil spring 104 is disposed and held in the gap between the rod portion 112b of the support body 112 and the tubular portion 103a of the valve seat hold-down member 103. One end of the compression coil spring 104 presses the stepped portion 112d of the support body 112 of the valve element 102, and the other end presses the inner surface of the partition portion 103b of the valve seat hold-down member 103. Therefore, the compression coil spring 104 biases the valve element 102 against the valve seat hold-down member 103 toward the closed position where the ball 111 closes the inlet 113.

[0055] The first communication holes 105 are formed along the radial direction of the valve seat holding member 103 and are spaced apart in the circumferential direction. The first communication holes 105 communicate between the arrangement space 115 and the annular flow path 155.

[0056] The accommodating hole 151 opens to the outside through an opening 152. The opening 152 has an inner diameter larger than that of the accommodating hole 151. The closing member 153 is cylindrical and has a threaded portion 153a formed on its outer peripheral surface. The threaded portion 153a of the closing member 153 screws into a threaded portion 152a formed on the inner peripheral surface of the opening 152. The closing member 153 is provided with a ring-shaped seal member 122 at one end in the axial direction (horizontal direction HD), which seals the accommodating hole 151 (cylinder block 38) by coming into close contact with the end face of the accommodating hole 151. Therefore, a sealed space 116 is defined between the valve seat hold-down member 103 and the closing member 153 at the accommodating hole 151 and the opening 152.

[0057] <Discharge valve operation> When the pressure in the compression chamber 43 (see FIG. 3) becomes high, the high pressure acts on the ball 111 of the valve element 102, causing the valve element 102 to move backward against the biasing force of the compression coil spring 104 and opening the inlet 113. Then, liquid hydrogen in the compression chamber 43 flows from the inlet hole 154 through the inlet 113 into the discharge valve 42, is discharged from the discharge port 114 into the annular flow path 155, and is discharged to the outside of the cylinder block 38 through the discharge hole.

[0058] At this time, the valve element 102 moves backward and compresses the compression coil spring 104, reducing the volume of the arrangement space 115 and increasing the pressure, causing the liquid hydrogen remaining in the arrangement space 115 to flow through the outer periphery of the valve element 102 to the discharge port 114. However, the discharge valve 42 of this embodiment is provided with a first communication hole 105 that connects the arrangement space 115 to the annular flow path 155. Therefore, when the volume of the arrangement space 115 decreases and the pressure increases, the liquid hydrogen remaining in the arrangement space 115 is pushed out from the arrangement space 115 to the annular flow path 155 through the first communication hole 105. This reduces the flow of liquid hydrogen from the arrangement space 115 to the discharge port 114, preventing the valve element 102 from being hindered from moving backward and reducing damage to the valve element 102 due to cavitation erosion.

[0059] [Second embodiment] 7 is a cross-sectional view showing a discharge valve of the second embodiment. Note that members having the same functions as those in the first embodiment described above are given the same reference numerals and detailed description thereof will be omitted.

[0060] As shown in FIG. 7, the discharge valve 42A is provided in an accommodating hole 151 formed in the cylinder block 38, and includes a valve seat 101, a valve body 102, a valve seat pressing member 103A, a compression coil spring 104, a first communication hole (first communication portion) 105, and a second communication hole (second communication portion) 106.

[0061] The second communication hole 106 is formed in the axial direction in the partition wall portion 103b of the valve seat hold-down member 103A. The second communication hole 106 connects the sealed space portion 116 and the arrangement space portion 115. In the second embodiment, the second communication hole 106, which directly connects the sealed space portion 116 and the arrangement space portion 115, is formed in the valve seat hold-down member 103A.

[0062] When the pressure of liquid hydrogen acts on the ball 111 of the valve element 102, the valve element 102 moves backward against the biasing force of the compression coil spring 104, opening the inlet 113. Then, liquid hydrogen in the compression chamber 43 flows from the inlet hole 154 through the inlet 113 into the discharge valve 42, is discharged from the discharge port 114 into the annular flow path 155, and is then discharged through the discharge hole.

[0063] At this time, the volume of the arrangement space 115 decreases as the valve element 102 moves backward, and liquid hydrogen remaining in the arrangement space 115 is pushed out from the arrangement space 115 through the first communication hole 105 to the annular flow path 155. As a result, the flow of liquid hydrogen from the arrangement space 115 to the discharge port 114 decreases, preventing the valve element 102 from being hindered from moving backward, and also preventing damage to the valve element 102 due to cavitation erosion.

[0064] Furthermore, when the valve element 102 retracts and the pressure in the arrangement space 115 increases, the pressure in the arrangement space 115 becomes higher than the pressure in the sealing space 116, and a load acts in a direction that moves the valve seat hold-down member 103A away from the valve seat 101. This reduces the pressing force that the valve seat 101 exerts on the end face of the accommodation hole 151 (cylinder block 38) via the sealing member 121, which may reduce the sealing performance of the arrangement space 115. However, the discharge valve 42A of the present embodiment is provided with a second communication hole 106 that communicates between the arrangement space 115 and the sealing space 116. Therefore, even if the volume of the arrangement space 115 decreases, no pressure difference occurs between the arrangement space 115 and the sealing space 116. This prevents the valve seat hold-down member 103A from being pressed against the end face of the accommodation hole 151 (cylinder block 38) and the sealing performance of the arrangement space 115 by the sealing member 121.

[0065] [Third embodiment] Figure 8 shows Third embodiment 10 is a cross-sectional view showing a discharge valve of the first embodiment. Note that members having the same functions as those in the first embodiment described above are given the same reference numerals and detailed description thereof will be omitted.

[0066] As shown in FIG. 8, the discharge valve 42B is provided in a receiving hole 151 formed in the cylinder block 38, and includes a valve seat 101, a valve body 102, a valve seat pressing member 103, a compression coil spring 104, a first communication hole 105, and a second communication hole (second communication portion) 106A.

[0067] The second communication holes 106A are formed in the cylinder block 38 radially outward of the valve seat hold-down member 103, and are provided in plurality at intervals in the circumferential direction of the valve seat hold-down member 103. The second communication holes 106A communicate between the sealed space 116 and the annular flow path 155 (discharge hole). In the third embodiment, the second communication holes 106A indirectly communicate between the sealed space 116 and the annular flow path 155 via the second communication holes 106A.

[0068] When the pressure of liquid hydrogen acts on the ball 111 of the valve element 102, the valve element 102 moves backward against the biasing force of the compression coil spring 104, opening the inlet 113. Then, liquid hydrogen in the compression chamber 43 flows from the inlet hole 154 through the inlet 113 into the discharge valve 42, is discharged from the discharge port 114 into the annular flow path 155, and is then discharged through the discharge hole.

[0069] At this time, the volume of the arrangement space 115 decreases as the valve element 102 moves backward, and liquid hydrogen remaining in the arrangement space 115 is pushed out from the arrangement space 115 through the first communication hole 105 to the annular flow path 155. As a result, the flow of liquid hydrogen from the arrangement space 115 to the discharge port 114 decreases, preventing the valve element 102 from being hindered from moving backward, and also preventing damage to the valve element 102 due to cavitation erosion.

[0070] Furthermore, when the valve element 102 retracts, the liquid hydrogen in the arrangement space 115 is pushed out through the first communication hole 105 to the annular flow path 155, which is in communication with the sealed space 116 via the second communication hole 106A. Therefore, no pressure difference occurs between the arrangement space 115 and the sealed space 116. Furthermore, no load acts in the direction of moving the valve seat holding member 103 away from the valve seat 101, and the sealing of the arrangement space 115 by the seal member 121 is ensured.

[0071] Furthermore, when the discharge valve 42B is assembled in the housing hole 151 of the cylinder block 38, air remains inside the discharge valve 42B. In an environment using liquid hydrogen as a cryogenic fluid, the remaining air becomes liquid or solid, generating impurities that may cause malfunction or damage to the pump. Therefore, it is necessary to supply an inert gas or hydrogen gas into the discharge valve 42B to push out and discharge the remaining air. At this time, because the annular flow path 155 is connected to the sealed space 116 via the second communication hole 106A, the inert gas or hydrogen gas can be supplied from the annular flow path 155 through the second communication hole 106A to the sealed space 116, thereby discharging the air remaining in the sealed space 116.

[0072] [Fourth embodiment] 9 is a cross-sectional view showing a discharge valve of the fourth embodiment. Members having the same functions as those in the first embodiment described above are given the same reference numerals and detailed description thereof will be omitted.

[0073] As shown in FIG. 9, the discharge valve 42C is provided in an accommodating hole 151 formed in the cylinder block 38, and includes a valve seat 101, a valve body 102A, a valve seat pressing member 103, a compression coil spring 104, and a first communication hole 105A.

[0074] The valve body 102A has a ball 111 and a support body 112A. The support body 112A is cylindrical and has a receiving portion 112a and a rod portion 112b. The first communication hole 105A has a first hole 105a and a second hole 105b. The first hole 105a is formed along the axial direction of the rod portion 112b of the support body 112A. The second holes 105b are formed along the radial direction of the receiving portion 112a of the support body 112A, and a plurality of second holes 105b are provided at intervals in the circumferential direction.

[0075] One end of the first hole 105a and one end of each of the second holes 105b communicate with each other inside the support 112A. The other end of the first hole 105a communicates with the arrangement space 115, and the other end of each of the second holes 105b communicates with the discharge port 114. Therefore, the first communication hole 105A communicates between the arrangement space 115 and the annular flow path 155.

[0076] When the pressure of liquid hydrogen acts on the ball 111 of the valve element 102A, the valve element 102A moves backward against the biasing force of the compression coil spring 104, opening the inlet port 113. Then, liquid hydrogen in the compression chamber 43 flows from the inlet port 154 through the inlet port 113 into the discharge valve 42, is discharged from the discharge port 114 into the annular flow path 155, and is then discharged through the discharge hole.

[0077] At this time, the volume of the arrangement space 115 decreases due to the retraction of the valve element 102A, and the liquid hydrogen remaining in the arrangement space 115 is pushed out from the arrangement space 115 through the first communication hole 105 to the annular flow path 155. As a result, the flow of liquid hydrogen from the arrangement space 115 to the discharge port 114 decreases, preventing the retraction of the valve element 102A from being hindered, and also preventing damage to the valve element 102A due to cavitation erosion.

[0078] [Effects of this embodiment] The discharge valve of the first aspect comprises a cylinder block (casing) 38 having an accommodation hole 151 communicating with the annular flow path 155, with an inlet hole 154 and an annular flow path (fluid discharge hole) 155 each communicating with the annular flow path 155; a valve seat 101 arranged in the accommodation hole 151 and having an inlet 113 communicating with the inlet hole 154 and an outlet 114 communicating with the annular flow path 155; a valve body 102, 102A supported in the accommodation hole 151 so as to be movable between a closed position that closes the inlet 113 and an open position that opens the inlet 113; and a first communication hole (first communication portion) 105, 105A that connects the annular flow path 155 to an arrangement space portion 115 on the opposite side of the valve body 102, 102A in the accommodation hole 151 from the inlet 113.

[0079] In the discharge valve according to the first aspect, when high-pressure liquid hydrogen acts on the valve disc 102, 102A, the valve disc 102, 102A moves backward, and when the inlet 113 is opened, liquid hydrogen remaining in the arrangement space 115 flows through the first communication holes 105, 105A to the annular flow path 155. This reduces the flow of liquid hydrogen from the arrangement space 115 to the discharge port 114, suppressing obstruction to the backward movement of the valve disc 102 and suppressing damage to the valve disc 102 due to cavitation erosion. As a result, the operability of the valve disc 102, 102A can be improved and damage to the valve disc 102, 102A can be suppressed.

[0080] The discharge valve according to the second aspect has a compression coil spring (biasing member) 104 that is arranged in the arrangement space 115 and biases the valve bodies 102, 102A to the closed position, thereby improving the operability of the valve bodies 102, 102A.

[0081] The discharge valve according to the third aspect is the discharge valve according to the first aspect, and furthermore, the valve seat 101 is positioned in the cylinder block 38 by valve seat holding members 103, 103A that define the arrangement space 115 and are fixed to the accommodating hole 151, and a compression coil spring 104 is disposed between the valve body 102, 102A and the valve seat holding members 103, 103A. This allows the valve seat 101 to be appropriately fixed to the cylinder block 38 by the valve seat holding members 103, 103A.

[0082] The discharge valve according to the fourth aspect is the discharge valve according to the second aspect, and further includes a first communication hole 105 formed in the valve seat hold-down member 103 to communicate the arrangement space 115 with the annular flow path 155. Thus, by forming the first communication hole 105 in the valve seat hold-down member 103, the structure can be simplified.

[0083] The discharge valve according to the fifth aspect is the discharge valve according to the second aspect, and further includes a first communication hole 105A formed in the valve element 102A to communicate the arrangement space 115 with the annular flow path 155. Thus, by forming the first communication hole 105A in the valve element 102A, the amount of liquid hydrogen that flows between the valve seat 101 and the valve element 102A can be reduced, and the operability of the valve element 102A can be improved.

[0084] A discharge valve according to a sixth aspect is the discharge valve according to any one of the first to fourth aspects, further comprising: an opening 152 that opens the accommodation space 15 to the outside in the cylinder block 38; the opening 152 is closed from the outside by a closing member 153 via a seal member 122, thereby forming a sealed space 116 between the valve seat holding members 103, 103A and the closing member 153; and second communication holes (second communication portions) 106, 106A that communicate the sealed space 116 with the arrangement space 115. As a result, even if the valve discs 102, 102A are retracted and the volume of the arrangement space 115 decreases, no pressure difference is generated between the arrangement space 115 and the sealed space 116. As a result, no load acts in a direction that moves the valve seat holding members 103, 103A away from the valve seat 101, and high sealing of the arrangement space 115 by the seal member 121 can be ensured.

[0085] The discharge valve according to the seventh aspect is the discharge valve according to the fifth aspect, and further includes a second communication hole 106 formed in the valve seat holding member 103A to communicate between the sealed space 116 and the arrangement space 115. This allows the second communication hole 106 to be formed in the valve seat holding member 103A, thereby simplifying the structure.

[0086] The discharge valve according to the eighth aspect is the discharge valve according to the fifth aspect, and further includes a second communication hole 106A formed in the cylinder block 38 to communicate the sealed space 116 with the annular flow path 155. This eliminates the need to change the valve seat 101, the valve element 102, and the valve seat pressing member 103, and allows for simplification of the discharge valve 42C itself.

[0087] The boost pump according to the ninth aspect includes an intake valve 41 that draws liquid hydrogen (low-temperature fluid) into a compression chamber 43, a piston 37 that compresses the liquid hydrogen drawn from the intake valve 41 into the compression chamber 43, and discharge valves 42, 42A, 42B, and 42C that discharge the liquid hydrogen compressed by the piston 37. As a result, the flow of liquid hydrogen from the arrangement space 115 to the discharge port 114 is reduced in the discharge valves 42, 42A, 42B, and 42C, preventing obstruction to the retraction movement of the valve element 102 and preventing damage to the valve element 102 due to cavitation erosion. As a result, the operability of the valve elements 102 and 102A can be improved and damage to the valve elements 102 and 102A can be prevented.

[0088] A hydrogen supply system according to a tenth aspect includes a compressor 21 having the boost pump 32 of the eighth aspect and compressing liquid hydrogen as a cryogenic fluid, an evaporator 22 that vaporizes the liquid hydrogen compressed by the compressor 21, and a dispenser 23 that supplies hydrogen gas vaporized by the evaporator 22. This reduces the flow of liquid hydrogen from the arrangement space 115 to the discharge port 114 in the discharge valves 42, 42A, 42B, 42C, suppressing obstruction to the retraction movement of the valve element 102 and suppressing damage to the valve element 102 due to cavitation erosion. As a result, the operability of the valve elements 102, 102A can be improved and damage to the valve elements 102, 102A can be suppressed.

[0089] In the above embodiment, the discharge valve 42 has been described as including the valve seat 101, the valve element 102, the valve seat holding member 103, and the compression coil spring 104, but the valve seat holding member 103 and the compression coil spring 104 may be eliminated. For example, the cylinder block 38 serving as the casing may be configured to function as the valve seat holding member 103. Furthermore, the inlet 113 may be closed by biasing the valve element 102 using the pressure difference between the compression chamber 43 and the discharge hole which is the discharge destination, i.e., the pressure in the annular flow path 155. [Explanation of symbols]

[0090] 10 Hydrogen supply system 11 Container 12 vehicles 21 Compression device 22 Evaporator 23 Dispenser 31 Drive motor 32 Booster pump 33 Reducer 34 Crank mechanism 35 Crosshead 36 Piston rod 37 Piston 38 Cylinder block (casing) 39 Container 41 Intake valve 42, 42A, 42B, 42C discharge valve 43 Compression chamber 51 Fitting hole 52 recess 53 Communication hole 61 Valve casing 62 First valve body 63 Second valve body 64 Pressing member 71 Space section 72 Through hole 73 Suction hole 74 Discharge hole 75 Nut 76 Spring support member 77 Compression coil spring 81, 82 sealing member 91 Fastening bolt 92 Suction pipe 101 Valve seat 102 Valve body 103 Valve seat retainer 104 Compression coil spring (biasing member) 105,105A 1st communication hole (1st communication part) 106,106A 2nd communication hole (2nd communication part) 111 Ball 112,112A Support 113 Inlet 114 Discharge port 115 Placement space 116 Sealed space 121,122 Sealing material 151 accommodation hole (accommodation space) 152 Opening 153 Closure member 154 Inflow hole (fluid inflow hole) 155 Annular flow path (fluid discharge hole)

Claims

1. a casing having a fluid inlet hole and a fluid discharge hole, each of which communicates with the fluid discharge hole, and an accommodation space portion which communicates with the fluid discharge hole; a valve seat having a cylindrical shape, disposed in the accommodation space, and having an inlet communicating with the fluid inlet hole and an outlet communicating with the fluid outlet hole; a valve body supported in the accommodation space portion so as to be movable between a closing position for closing the inlet and an opening position for opening the inlet; a valve seat pressing member having a cylindrical shape with one axial end closed, for positioning the valve seat in the casing and for defining an arrangement space on the opposite side of the inlet port with respect to the valve body in the accommodation space; a first communication portion that communicates the arrangement space with the fluid discharge hole in a movement region of the valve body from the closed position to the position where the valve body opens the inlet and abuts against the valve seat pressing member; Equipped with The casing is provided with an opening that opens the accommodation space to the outside, and the opening is closed from the outside by a closing member via a sealing member, thereby forming a sealed space between the valve seat holding member and the closing member, and a second communication portion is provided that communicates the sealed space with the arrangement space, thereby ensuring the sealing of the arrangement space without the application of a load in a direction that moves the valve seat holding member away from the valve seat. Discharge valve.

2. When the valve body opens the inlet from the closed position and abuts against the valve seat pressing member, an end of the valve body on the inlet side is positioned between the discharge port and the first communication portion. The discharge valve of claim 1 .

3. a biasing member disposed in the arrangement space and biasing the valve body to the closed position; The discharge valve of claim 1 .

4. The biasing member is a compression spring disposed between the valve body and the valve seat pressing member. The discharge valve of claim 3.

5. the first communication portion is a first communication hole formed in the valve seat pressing member and communicating the arrangement space with the fluid discharge hole; The discharge valve of claim 4.

6. the first communication portion is a first communication hole formed in the valve body and communicating the arrangement space with the discharge port; The discharge valve of claim 4.

7. The second communication portion is a second communication hole formed in the valve seat pressing member, which communicates the sealing space portion with the arrangement space portion. The discharge valve of claim 1 .

8. the second communication portion is a second communication hole formed in the casing and communicating the sealed space portion with the fluid discharge hole; The discharge valve of claim 1 .

9. an intake valve for drawing the cryogenic fluid into the compression chamber; a piston that compresses the low-temperature fluid drawn into the compression chamber through the intake valve; a discharge valve according to claim 1 that discharges the cryogenic fluid compressed by the piston; A booster pump comprising:

10. A compression device having the boost pump according to claim 9 and compressing liquid hydrogen as a cryogenic fluid; an evaporator that vaporizes the liquid hydrogen compressed by the compressor; a dispenser for supplying the hydrogen gas vaporized by the vaporizer; A hydrogen supply system comprising:

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