Accumulator

Abstract

To provide a pressure accumulator which can store an extremely-low temperature liquefied gas by evaporating it and injecting it into the pressure accumulator from the outside through piping.SOLUTION: A pressure accumulator has: a metal-made cylinder body for evaporating and storing a liquefied gas in an internal storage space; a lid body formed with an insertion hole for allowing the insertion of piping therein, fixing the piping which is inserted into the insertion hole, and blocking an opening end part of the cylinder body in a state that a clearance communicating with the storage space of the cylinder body is formed between an internal peripheral face of the cylinder body and itself; a seal structure arranged between an external peripheral part of the lid body and an internal peripheral part of the cylinder body, and sealing at least a part of the clearance; and a fixing member arranged at the opening end part of the cylinder body, screw-fastened to the internal peripheral face of the cylinder body at the external peripheral face, and fixing the lid body by supporting it from the outside.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a pressure accumulator for storing vaporized liquefied gas.

Background Art

[0002] Conventionally, pressure accumulators for storing vaporized liquefied gas inside are variously known and already in practical use. Generally, liquefied hydrogen carried by a liquid hydrogen truck and stored in a storage tank is vaporized in a vaporizer, compressed by a compressor to a high pressure, and then injected into the pressure accumulator through a pipe. For example, in the hydrogen gas pressure accumulator disclosed in Patent Document 1 below, it has a steel cylindrical cylinder part for storing vaporized liquefied gas inside, a lid part for sealing both ends of the cylindrical cylinder part in an openable and closable manner, and a screwing part for fixing the lid part to the cylindrical cylinder part.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, it is conceivable to adopt a configuration that eliminates the need for a vaporizer by injecting extremely low - temperature liquefied gas from the outside through a pipe, vaporizing it inside, and storing it in a pressure accumulator. However, in the hydrogen gas pressure accumulator disclosed in Patent Document 1, the cylindrical cylinder can withstand only about - 30°C, while the temperature of liquid hydrogen is about - 260°C. Therefore, due to heat conduction by the extremely low - temperature liquid hydrogen flowing through the pipe, the lid part becomes low - temperature, and the cylindrical cylinder thermally conducted from the lid part becomes low - temperature, which may cause brittle fracture of the cylindrical ring.

[0005] The present invention has been made to solve the above-described problems, and even when a cryogenic liquefied gas is injected from the outside into the inside through a pipe, the cylindrical body does not cause brittle fracture, and the object is to provide a pressure accumulator capable of vaporizing and storing the liquefied gas.

Means for Solving the Problems

[0006] The pressure accumulator according to the present invention is a pressure accumulator that vaporizes and stores a cryogenic liquefied gas by injecting it from the outside into the inside through a pipe, and includes a metal cylindrical body that vaporizes and stores the liquefied gas in an internal storage space, a through-hole through which the pipe penetrates is formed, the pipe passed through the through-hole is fixed, and a lid that closes the open end of the cylindrical body with a gap communicating with the storage space of the cylindrical body provided between the lid and the inner peripheral surface of the cylindrical body, a seal structure portion provided between the outer peripheral portion of the lid and the inner peripheral portion of the cylindrical body and filling at least a part of the gap, and a fixing member provided at the open end of the cylindrical body, the outer peripheral surface of which is screwed and fastened to the inner peripheral surface of the cylindrical body and supports and fixes the lid from the outside.

Effects of the Invention

[0007] According to the present invention, a gap is provided between the outer peripheral portion of the lid and the inner peripheral portion of the cylindrical body, and at least a part of the gap is filled with the seal structure portion, so that the gap functions as a heat insulating layer, suppressing heat conduction from the lid to the cylindrical body, and suppressing brittle fracture of the cylindrical body. Therefore, it becomes possible to vaporize and store a cryogenic liquefied gas by injecting it from the outside into the inside through a pipe.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will be omitted or simplified as appropriate. In addition, regarding the configurations shown in each figure, the shape, size, arrangement, etc. can be appropriately changed within the scope of the present invention.

[0010] Embodiment 1. FIG. 1 is a sectional view schematically showing the internal structure of one end side of a pressure accumulator according to Embodiment 1. The pressure accumulator 100 according to the present Embodiment 1 vaporizes and stores cryogenic liquefied gas by injecting it from the outside through a pipe 200 into the interior. In the present Embodiment 1, the case where the liquid gas is liquefied hydrogen as an example will be described. The cryogenic liquefied hydrogen is, for example, about -260°C. Note that the liquid gas may be, for example, liquid nitrogen, liquid helium, etc. in addition to liquefied hydrogen. When the liquid gas is liquefied hydrogen, the pressure accumulator 100 is installed, for example, at a hydrogen station that supplies hydrogen to a vehicle or the like.

[0011] (Pressure accumulator 100) As shown in FIG. 1, the pressure accumulator 100 includes a metal cylindrical body 1, a lid body 2 that closes the open end of the cylindrical body 1, a seal structure portion 3 provided between the outer peripheral portion of the lid body 2 and the inner peripheral portion of the cylindrical body 1, a fixing member 4 that supports and fixes the lid body 2 from the outside, and a temperature detection means 5.

[0012] (Cylindrical body 1) The cylindrical body 1 vaporizes liquefied hydrogen in the internal storage space 10 to store hydrogen gas. The inner wall surface of the accumulator 100 is the part that comes into contact with the liquefied hydrogen and hydrogen gas. An extremely low-temperature liquefied gas is injected into the storage space 10 of the cylindrical body 1 through the pipe 200 from the outside. The pipe 200 is formed of, for example, austenitic stainless steel. This is because austenitic stainless steel is excellent in brittleness against liquid hydrogen and can ensure strength against extremely low temperatures. The hydrogen gas stored in the storage space 10 of the cylindrical body 1 is supplied to a vehicle or the like through a pipe communicating with the outside.

[0013] The cylindrical body 1 is formed of, for example, low alloy steel. Low alloy steel is, for example, chromium molybdenum steel, nickel chromium molybdenum steel, manganese chromium steel, manganese steel, or boron-added steel. The cylindrical body 1 has a cylindrical shape with both ends open, and female screw portions 11 are formed on the inner peripheral surfaces of both ends. Note that the cylindrical body 1 may have a bottomed cylindrical shape with only one end open, for example. Also, the cylindrical body 1 is not limited to a cylindrical shape and may have other shapes such as a rectangular tube shape. Further, the outer surface of the cylindrical body 1 may be covered with CFRP (Carbon Fiber Reinforced Plastics) as a material other than metal. From the viewpoint of vaporization efficiency, the thickness ratio of the CFRP layer to the thickness of the cylindrical body 1 (thickness of the CFRP layer / thickness of the cylindrical body 1) is preferably 50% or less, and more preferably 25% or less. This is because if the CFRP layer is too thick, the heat insulation effect becomes apparent and the vaporization efficiency of the liquefied hydrogen decreases.

[0014] (Cover body 2) The cover body 2 closes the open end portion of the cylindrical body 1. The cover body 2 is formed of austenitic stainless steel and has an inner cover body 20 disposed on the storage space 10 side of the cylindrical body 1 and an outer cover body 21 formed of low alloy steel and disposed on the fixed member 4 side of the cylindrical body 1. A through hole 20a for passing the pipe 200 is formed in the inner cover body 20, and the pipe 200 passed through the through hole 20a is fixed. A through hole 21a for passing the pipe 200 is formed in the outer cover body 21.

[0015] The inner lid 20 faces the storage space 10 of the cylindrical body 1 and is constantly exposed to extremely low-temperature liquid hydrogen. Since it is made of austenitic stainless steel, it has excellent brittleness against liquid hydrogen and can ensure strength against extremely low temperatures. Note that the inner lid 20 may be made of other materials as long as it has excellent brittleness against liquid hydrogen and can withstand extremely low temperatures. As an example, the length of the inner lid 20 in the pipe axis direction X of the cylindrical body 1 is about 30 mm. This is because a length of about 30 mm is sufficient for the strength against liquid hydrogen. However, the length of the inner lid 20 is not limited to about 30 mm and shall be designed to be appropriately changed according to the size and shape of the cylindrical body 1.

[0016] Also, the inner lid 20 has a screw fastening portion 22 for fixing the pipe 200 passed through the through hole 20a by screw fastening. Specifically, a female screw is formed on the inner peripheral portion of the through hole 20a of the inner lid 20, and a male screw that fastens to the female screw of the inner lid 20 is formed on the outer peripheral portion of the pipe 200. By screw-fastening the inner lid 20 and the pipe 200, the pipe 200 can be securely fixed against the internal pressure of the hydrogen gas stored in the storage space 10 of the cylindrical body 1.

[0017] A seal member 6 is provided between the inner peripheral portion of the inner lid 20 and the outer peripheral portion of the pipe 200. This is to prevent the hydrogen gas stored in the storage space 10 of the cylindrical body 1 from leaking to the outside through the space between the inner peripheral portion of the inner lid 20 and the outer peripheral portion of the pipe 200. The seal member 6 is an O-ring as an example. However, the seal member 6 is not limited to an O-ring and may be other members as long as it can prevent the hydrogen gas stored in the storage space 10 of the cylindrical body 1 from leaking through the space between the inner peripheral portion of the inner lid 20 and the outer peripheral portion of the pipe 200.

[0018] The inner lid 20 is fitted into the open end of the cylindrical body 1 with a gap S provided between it and the inner peripheral surface of the cylindrical body 1, which communicates with the storage space 10 of the cylindrical body 1. The gap S is, for example, about 0.5 mm and is provided along the pipe axis direction X of the cylindrical body 1. By making the gap S function as a heat insulation layer, it is possible to suppress the situation where the temperature of the cylindrical body 1 drops due to heat conduction from the pipe 200 through which extremely low temperature liquid hydrogen passes to the inner lid 20 that has become low temperature. Also, by providing the gap S, the inner lid 20 can be fitted into the open end of the cylindrical body 1.

[0019] The outer lid 21 is provided to increase the strength against the internal pressure of the hydrogen gas inside the cylindrical body 1. This is because the strength of only the inner lid 20 with a length in the pipe axis direction X of about 30 mm may be insufficient against the internal pressure of the hydrogen gas. The outer lid 21 is formed of, for example, low alloy steel such as chromium molybdenum steel, nickel chromium molybdenum steel, manganese chromium steel, manganese steel, or boron added steel. Since low alloy steel is less costly than austenitic stainless steel, it can contribute to reducing the manufacturing cost. Note that the outer lid 21 is not limited to low alloy steel and may be formed of other materials as long as it can increase the strength against the internal pressure of the hydrogen gas stored in the storage space 10 of the cylindrical body 1.

[0020] A heat insulation member 7 is provided between the inner lid 20 and the outer lid 21. This is to prevent heat conduction from the inner lid 20 to the outer lid 21. Also, a heat insulation member 8 is provided between the outer lid 21 and the pipe 200. This is to prevent heat conduction of the extremely low temperature of the pipe 200 through which extremely low temperature liquid hydrogen passes to the outer lid 21. This is because the outer lid 21 made of low alloy steel may cause brittle fracture when extremely low temperature is heat-conducted and the temperature drops. Note that the materials of the heat insulation members 7 and 8 are, as an example, ceramics.

[0021] (Sealing structure part 3) The seal structure portion 3 is provided between the outer peripheral portion of the inner lid body 20 and the inner peripheral portion of the cylindrical body 1, and fills at least a part of the gap S. The seal structure portion 3 is, for example, a resin or metal seal material such as an O-ring. By providing the seal structure portion 3, it is possible to prevent the hydrogen gas stored in the storage space 10 of the cylindrical body 1 from leaking to the outside through the gap S. Note that filling at least a part of the gap S means that all of the gap S may be filled or a part of the gap S may be filled. Also, as shown in the figure, a part of the gap S is preferably the end portion on the storage space 10 side of the cylindrical body 1, but may be, for example, the end portion on the outer lid body 21 side or the middle portion. Further, the seal structure portion 3 is not limited to an O-ring, and other members may be used as long as the hydrogen gas stored in the storage space 10 of the cylindrical body 1 can be prevented from flowing into the gap S between the outer peripheral portion of the inner lid body 20 and the inner peripheral portion of the cylindrical body 1. For example, a member such as a metal hollow O-ring that can be sealed by a combination of metal and resin may be used. When using a resin O-ring, the cold resistance limit temperature is preferably -30°C or lower, and more preferably -50°C or lower.

[0022] (Fixing member 4) The fixing member 4 is provided at the open end of the cylindrical body 1, and its outer peripheral surface is screwed and fastened to the inner peripheral surface of the cylindrical body 1 to support and fix the lid body 2 from the outside of the storage space 10. Specifically, the fixing member 4 is a ground nut having a male screw portion formed on its outer peripheral surface for screwing and fastening to the female screw portion 11 of the cylindrical body 1. By being screwed and fastened to the cylindrical body 1, the position of the fixing member 4 in the pipe axis direction X is fixed. The fixing member 4 can support the lid body 2 by having one end surface abut against the outer surface of the outer lid body 21 with respect to the lid body 2 on which the axial force in the pipe axis direction X due to the high-pressure hydrogen gas stored in the storage space 10 acts. The piping 200 passes through the hollow hole of the fixing member 4. The thickness of the fixing member 4 in the radial direction can be arbitrarily determined. However, since the fixing member 4 has a structure for supporting the pressure received by the inner lid body 20, if the wall thickness in the radial direction is too thin, the lid body 2 cannot be sufficiently supported. Therefore, the thickness of the fixing member 4 in the radial direction is preferably set to a thickness that can secure an area capable of supporting 40% or more of the area where the inner lid body 20 receives pressure, and more preferably a thickness that can secure an area capable of supporting 60% or more. As an example, when the diameter of the inner lid body 20 is 300 mm, the area of the inner lid body 20 receiving pressure is 70650 mm 2 becomes. Note that the area of the inner lid body 20 is calculated including the portion through which the piping 200 passes, but in practice, it is desirable to calculate excluding the portion through which the piping 200 passes. On the other hand, when the wall thickness of the fixing member 4 is 50 mm, the area supported by the fixing member 4 is 39250 mm 2 becomes. In this case, the fixing member 4 can secure an area capable of supporting 56% of the area where the inner lid body 20 receives pressure.

[0023] (Temperature detection means 5) The temperature detection means 5 is, for example, a thermocouple, and detects the temperature of the hydrogen gas stored in the storage space 10 of the cylindrical body 1 or the temperature of the inner lid body 20. In the accumulator 100 according to the first embodiment, the temperature of the hydrogen gas stored inside the cylindrical body 1 or the temperature of the inner lid body 20 is monitored using the temperature detection means 5. In the accumulator 100, based on the detection value of the temperature detection means 5, the conditions of the liquid hydrogen injected from the pipe 200 are determined. The conditions of the liquid hydrogen are the flow rate, flow velocity, injection time, etc. The accumulator 100 is provided with a control unit, and the control unit determines the conditions of the liquid hydrogen based on the detection value of the temperature detection means 5, and adjusts the flow rate of the liquefied hydrogen passing through the pipe 200. Note that although it is desirable for the accumulator 100 to be provided with the temperature detection means 5, it is not necessarily required to be provided, and it may be omitted.

[0024] FIG. 2 is a cross-sectional view schematically showing the internal structure on one end side, which is a modified example of the accumulator according to the first embodiment. The accumulator 100 shown in FIG. 1 has a screw fastening portion 22 for fixing the pipe 200 passed through the through hole 20a of the inner lid body 20 by screw fastening, whereas in the accumulator 100A shown in FIG. 2, the inner lid body 20 has a welded fixing portion 23 for fixing the pipe 200 passed through the through hole 20a by welding. The welded fixing portion 23 may be provided entirely along the pipe axis direction X or only partially. In this case, since the space between the inner peripheral portion of the inner lid body 20 and the outer peripheral portion of the pipe 200 is completely blocked, the seal member 6 shown in FIG. 1 becomes unnecessary.

[0025] By the way, it is conceivable to adopt a configuration in which a cryogenic liquefied gas is injected from the outside through the pipe 200, vaporized inside, and stored in the accumulator 100, thereby eliminating the need for a vaporizer. However, since the cylindrical body 1 can withstand only about -30°C, for example, while the temperature of the liquid hydrogen is about -260°C, for example, if the liquid hydrogen is injected into the accumulator 100, the lid body 2 will become cold due to heat conduction by the cryogenic liquid hydrogen flowing through the pipe 200, and the cylindrical body 1 thermally conducted from the lid body 2 will become cold, which may cause brittle fracture of the cylindrical body 1.

[0026] Therefore, as described above, in the accumulator 100 according to the first embodiment, a metal cylinder 1 for vaporizing and storing liquefied gas in an internal storage space 10, through holes 20a and 21a for passing through a pipe 200 are formed, and the pipe 200 passed through the through holes 20a and 21a is fixed, and a gap S communicating with the storage space 10 of the cylinder 1 is formed between the inner peripheral surface of the cylinder 1, and a lid 2 for closing the open end of the cylinder 1. Further, a seal structure portion 3 provided between the outer peripheral portion of the lid 2 and the inner peripheral portion of the cylinder 1 and filling at least a part of the gap S, and a fixing member 4 provided at the open end of the cylinder 1, the outer peripheral surface of which is screwed and fastened to the inner peripheral surface of the cylinder 1 to support and fix the lid 2 from the outside.

[0027] In this way, in the accumulator 100 according to the first embodiment, a gap S is provided between the outer peripheral portion of the lid 2 and the inner peripheral portion of the cylinder 1, and at least a part of the gap S is filled with the seal structure portion 3, so that the gap S functions as a heat insulating layer to suppress heat conduction from the lid 2 to the cylinder 1. That is, it is possible to suppress a situation in which the temperature of the cylinder 1 is lowered by the lid 2 that has been cooled by heat conduction from the pipe 200 through which extremely low-temperature liquid hydrogen passes, and it is possible to suppress brittle fracture of the cylinder 1. Therefore, the accumulator 100 according to the first embodiment can vaporize and store extremely low-temperature liquefied gas by injecting it into the inside through the pipe 200 from the outside.

[0028] Further, the lid 2 has a screw fastening portion 22 for fixing the pipe 200 passed through the through holes 20a and 21a by screw fastening. A seal member 6 for closing the space therebetween is provided between the inner peripheral portion of the lid 2 and the outer peripheral portion of the pipe 200. Therefore, the pipe 200 can be reliably fixed against the internal pressure of the hydrogen gas stored in the storage space 10 of the cylinder 1. In addition, it is possible to prevent a situation in which the hydrogen gas stored in the storage space 10 of the cylinder 1 leaks to the outside through the space between the inner peripheral portion of the inner lid 20 and the outer peripheral portion of the pipe 200.

[0029] The lid body 2 is formed of austenitic stainless steel and has an inner lid body 20 disposed on the side of the storage space 10 of the cylindrical body 1, and an outer lid body 21 formed of low alloy steel and disposed on the side of the fixing member 4. Therefore, the inner lid body 20 faces the storage space 10 of the cylindrical body 1 and is always exposed to cryogenic liquid hydrogen. Since it is formed of austenitic stainless steel, it is excellent in brittleness against liquid hydrogen and can ensure strength against cryogenic temperatures. Further, the outer lid body 21 can enhance the strength against the internal pressure of the hydrogen gas inside the cylindrical body 1, and by using low alloy steel, which is lower in cost than austenitic stainless steel, it is possible to contribute to reducing the manufacturing cost.

[0030] Heat insulating members 7 and 8 are provided between the inner lid body 20 and the outer lid body 21, and between the outer lid body 21 and the pipe 200, respectively. Therefore, heat conduction from the inner lid body 20 to the outer lid body 21 can be prevented, and the situation where the cryogenic temperature of the pipe 200 through which cryogenic liquid hydrogen passes conducts heat to the outer lid body 21 can be prevented, so that brittle damage to the outer lid body 21 due to temperature drop can be prevented.

[0031] The accumulators 100 and 100A according to the first embodiment have temperature detection means 5 for detecting the temperature of the vaporized liquefied gas stored in the storage space 10 of the cylindrical body 1 or the temperature of the lid body 2. Therefore, in the accumulators 100 and 100A according to the first embodiment, the temperature of the hydrogen gas stored inside the cylindrical body 1 or the temperature of the inner lid body 20 can be monitored using the temperature detection means 5, and based on the detection value of the temperature detection means 5, the conditions of the liquid hydrogen injected from the pipe 200 can be determined.

[0032] Embodiment 2. Next, the accumulator 101 according to the second embodiment will be described with reference to FIG. 3. FIG. 3 is a cross-sectional view schematically showing the internal structure on one end side of the accumulator according to the second embodiment. Note that the same components as those of the accumulator 100 described in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0033] (Lid body 2) The accumulator 101 according to Embodiment 2 has a lid 2 whose configuration is different from that of the accumulator 100 described in Embodiment 1. The lid 2 of the accumulator 101 according to Embodiment 2 is formed only of austenitic stainless steel.

[0034] The lid 2 has a screw fastening portion 22 for fixing the pipe 200 passed through the through hole 2a by screw fastening. Specifically, an internal thread is formed on the inner peripheral portion of the through hole 2a of the lid 2, and an external thread that is fastened to the thread of the lid 2 is formed on the outer peripheral portion of the pipe 200. By having the screw fastening portion 22 for screw-fastening the lid 2 and the pipe 200, the pipe 200 can be securely fixed against the internal pressure of the hydrogen gas stored in the storage space 10 of the cylindrical body 1.

[0035] A seal member 6 that closes the space therebetween is provided between the inner peripheral portion of the lid 2 and the outer peripheral portion of the pipe 200. This is to prevent a situation where the hydrogen gas stored in the storage space 10 of the cylindrical body 1 leaks to the outside through the gap between the inner peripheral portion of the lid 2 and the outer peripheral portion of the pipe 200. The seal member 6 is, as an example, an O-ring. However, the seal member 6 is not limited to an O-ring, and other members may be used as long as they can prevent the hydrogen gas stored in the storage space 10 of the cylindrical body 1 from leaking through the gap between the inner peripheral portion of the lid 2 and the outer peripheral portion of the pipe 200.

[0036] A heat insulating member 9 is provided between the lid 2 and the fixing member 4. This is to prevent heat conduction from the lid 2 to the fixing member 4. This is because the fixing member 4 may cause brittle fracture when heat is conducted at extremely low temperatures and the temperature decreases. Note that the material of the heat insulating member 9 is, as an example, ceramics. However, when the length of the lid 2 in the pipe axis direction is long and there is no possibility of heat conduction from the lid 2 to the fixing member 4, the heat insulating member 9 may be omitted.

[0037] FIG. 4 is a cross-sectional view schematically showing the internal structure of one end side of a modified example of the accumulator according to Embodiment 2. The accumulator 101 shown in FIG. 3 has a screw fastening portion 22 for fixing the pipe 200 passed through the through hole 2a of the lid body 2 by screw fastening. In contrast, in the accumulator 101A shown in FIG. 4, the lid body 2 has a welding fixing portion 23 for fixing the pipe 200 passed through the through hole 2a by welding. The welding fixing portion 23 may be provided over the entire length along the pipe axis direction X, or may be provided only partially. In this case, since the space between the inner peripheral portion of the lid body 2 and the outer peripheral portion of the pipe 200 is completely blocked, the seal member 6 shown in FIG. 3 becomes unnecessary.

[0038] As described above, also in the accumulators 101 and 101A according to the present Embodiment 2, a gap S is provided between the outer peripheral portion of the lid body 2 and the inner peripheral portion of the cylindrical body 1, and at least a part of the gap S is filled with the seal structure portion 3. Therefore, the gap S functions as a heat insulating layer, and heat conduction from the lid body 2 to the cylindrical body 1 can be suppressed. That is, it is possible to suppress a situation in which the temperature of the cylindrical body 1 decreases due to heat conduction from the pipe 200 through which extremely low temperature liquid hydrogen passes and the lid body 2 that has become low temperature. Therefore, the accumulator 101 according to the present Embodiment 2 can vaporize and store extremely low temperature liquefied gas by injecting it into the inside from the outside through the pipe 200.

[0039] The lid body 2 is formed of austenitic stainless steel. Therefore, the lid body 2 faces the storage space 10 of the cylindrical body 1 and is always exposed to extremely low temperature liquid hydrogen. However, since it is formed of austenitic stainless steel, it is excellent in brittleness against liquid hydrogen and can ensure strength against extremely low temperature.

[0040] Further, the accumulators 101 and 101A according to the present Embodiment 2 have a heat insulating member 9 provided between the lid body 2 and the fixing member 4. Therefore, heat conduction from the lid body 2 to the fixing member 4 can be prevented, and brittle damage of the fixing member 4 due to temperature drop can be prevented.

[0041] Embodiment 3. Next, the accumulator 102 according to Embodiment 3 will be described with reference to FIGS. 5 and 6. FIG. 5 is a cross-sectional view schematically showing the internal structure on one end side of the accumulator according to Embodiment 3. FIG. 6 is an explanatory view schematically showing the end face of the outer lid of the accumulator according to Embodiment 3. For the same components as the accumulators 100 and 101 described in Embodiments 1 and 2, the same reference numerals are given, and the description thereof will be omitted as appropriate.

[0042] As shown in FIG. 5, the cylindrical body 1 of the accumulator 102 according to Embodiment 3 has a first vent hole 1a for communicating the outside of the cylindrical body 1 with the gap S and injecting a gas for heat exchange from the outside of the cylindrical body 1 into the gap S, and a second vent hole 1b for communicating the outside of the cylindrical body 1 with the gap S and discharging the gas injected into the gap S through the first vent hole 1a to the outside of the cylindrical body 1. An injection pipe 300 for injecting gas is connected to the first vent hole 1a. Also, a discharge pipe 400 for discharging gas is connected to the second vent hole 1b. The gas is, for example, inert air, and preferably dehumidified if possible. Note that the gas may be an inert gas or other gas. The gas is injected into the gap S by being pressurized by a power device such as a compressor, circulates in the gap S, and is discharged to the outside of the cylindrical body 1. In the accumulator 102 according to Embodiment 3, by flowing gas through the gap S, the gas layer becomes a heat insulating layer, and the effect of suppressing heat conduction from the lid body 2 to the cylindrical body 1 can be enhanced. Further, in the accumulator 102, even if a situation occurs where the hydrogen gas stored in the storage space 10 of the cylindrical body 1 leaks into the gap S portion, the leaked hydrogen gas can be discharged from the second vent hole 1b.

[0043] Also, the lid body 2 is formed of austenitic stainless steel and has an inner lid body 20 disposed on the storage space side of the cylindrical body 1 and an outer lid body 21 formed of low alloy steel and disposed on the fixed member side. Among the end faces of the inner lid body 20 and the outer lid body 21 facing each other, a groove portion 24 for circulating the gas injected from the outside of the cylindrical body 1 into the gap S is formed on the end face of the outer lid body 21.

[0044] In FIG. 6, the thick line portion indicates the groove portion 24. As shown in FIG. 6, the groove portion 24 has a plurality of annular groove portions 24a and linear connecting groove portions 24b that connect the plurality of annular groove portions 24a. In the case of the illustrated example, the plurality of annular groove portions 24a are constituted by three circles surrounding the outer periphery of the through hole 21a. The three circles are formed in substantially equal intervals in order such that the larger circle surrounds the outer periphery of the smaller circle. Both ends of the connecting groove portion 24b communicate with the gap S, and it is formed in the radial direction so as to connect the three circles. The gas injected into the gap S enters from one end portion of the connecting groove portion 24b, flows into the annular groove portion 24a, and then is discharged from the other end side of the connecting groove portion 24b into the gap S. In this way, by circulating the gas injected from the outside of the cylindrical body 1 through the groove portion 24, the gas layer becomes a heat insulating layer, and the effect of suppressing heat conduction from the inner lid body 20 to the outer lid body 21 can be enhanced. Note that when the gas is dry air, even if the gas is cooled during heat exchange, condensation and freezing do not occur in the groove portion 24 of the lid body 21.

[0045] Although not shown in the figure, among the end faces of the inner lid body 20 and the outer lid body 21 facing each other, the groove portion 24 may be formed on the end face of the inner lid body 20. Further, among the end faces of the inner lid body 20 and the outer lid body 21 facing each other, the groove portion 24 may be formed on both end faces.

[0046] Further, the groove portion 24 is not limited to the illustrated shape. For example, the annular groove portion 24a is not limited to a circular shape, and may be a rectangular shape or other shapes. Further, the connecting groove portion 24b is not limited to a linear shape, and may be a curved shape, a zigzag shape, or other shapes. Further, the groove portion 24 may have a configuration such as a lattice shape or a spiral shape, or other shapes. In short, the groove portion 24 may have any shape as long as it can circulate the gas injected from the outside of the cylindrical body 1 to the end face of the inner lid body 20 or the end face of the outer lid body 21.

[0047] Further, it is desirable that the accumulator 102 is provided with the groove portion 24 on either one or both of the end faces of the inner lid body 20 and the outer lid body 21 facing each other, but it is not necessarily required to provide the groove portion 24, and it may be omitted.

[0048] Further, the accumulator 102 can also be applied to a configuration in which the lid body 2 is formed only of austenitic stainless steel as shown in FIGS. 3 and 4, for example. However, in this case, the groove portions 24 shown in FIGS. 5 and 6 are omitted.

[0049] Further, the accumulator 102 may be configured to perform control for determining the conditions of the gas injected into the gap S based on the detection value of the temperature detection means 5. The conditions of the gas are, for example, flow rate, flow velocity, injection time, and the like. Note that the accumulator 102 is not limited to the detection value of the temperature detection means 5, and other detection means may be used to determine the conditions of the gas injected into the gap S.

[0050] As described above, the accumulators (100, 100A, 101, 101A, 102) have been described based on the embodiments. However, the accumulators (100, 100A, 101, 101A, 102) are not limited to the configurations of the above-described embodiments. The configurations of the above-described accumulators (100, 100A, 101, 101A, 102) are merely examples, and may include other components. In short, the accumulators (100, 100A, 101, 101A, 102) include the scope of design changes and application variations that those skilled in the art normally make without departing from the technical idea thereof.

[0051] Hereinafter, aspects of the present disclosure will be collectively described as appendices.

[0052] (Appendix 1) An accumulator for vaporizing and storing a cryogenic liquefied gas by injecting it from the outside through a pipe, a metal cylinder for vaporizing and storing the liquefied gas in an internal storage space, a lid body that forms a through-hole through which the pipe passes, fixes the pipe passed through the through-hole, and closes the opening end of the cylinder while providing a gap communicating with the storage space of the cylinder between the lid body and the inner peripheral surface of the cylinder, a seal structure portion provided between the outer peripheral portion of the lid body and the inner peripheral portion of the cylinder to fill at least a part of the gap A pressure accumulator having a fixing member provided at an opening end of the cylindrical body, with an outer peripheral surface screwed and fastened to an inner peripheral surface of the cylindrical body to support and fix the lid body from the outside.

[0053] (Appendix 2) The lid body has a screw fastening portion for fixing the pipe passed through the through hole by screw fastening. The pressure accumulator according to Appendix 1, wherein a sealing member for closing the gap is provided between an inner peripheral portion of the lid body and an outer peripheral portion of the pipe.

[0054] (Appendix 3) The pressure accumulator according to Appendix 1, wherein the lid body has a welding fixing portion for fixing the pipe passed through the through hole by welding.

[0055] (Appendix 4) The pressure accumulator according to any one of Appendices 1 to 3, wherein the lid body is formed of austenitic stainless steel.

[0056] (Appendix 5) The pressure accumulator according to any one of Appendices 1 to 4, further having a heat insulating member provided between the lid body and the fixing member.

[0057] (Appendix 6) The lid body is formed of austenitic stainless steel and has an inner lid body disposed on the storage space side of the cylindrical body, and an outer lid body formed of low alloy steel and disposed on the fixing member side. The pressure accumulator according to any one of Appendices 1 to 3.

[0058] (Appendix 7) The pressure accumulator according to Appendix 6, wherein heat insulating members are provided between the inner lid body and the outer lid body, and between the outer lid body and the pipe, respectively.

[0059] (Appendix 8) The accumulator according to any one of Appendices 1 to 7, further comprising temperature detection means for detecting the temperature of the vaporized liquefied gas stored in the storage space of the cylinder body or the temperature of the lid body.

[0060] (Appendix 9) In the cylinder body, a first vent hole for communicating the outside of the cylinder body with the gap and injecting gas from the outside of the cylinder body into the gap, and a second vent hole for communicating the outside of the cylinder body with the gap and discharging the gas injected into the gap through the first vent hole to the outside of the cylinder body. The accumulator according to any one of Appendices 1 to 8.

[0061] (Appendix 10) The lid body is formed of austenitic stainless steel and has an inner lid body disposed on the storage space side of the cylinder body and an outer lid body formed of low alloy steel and disposed on the fixed member side. Among the end faces of the inner lid body and the outer lid body facing each other, a groove portion through which the gas injected into the gap circulates is formed on one or both of the end faces. The accumulator according to Appendix 9.

[0062] (Appendix 11) The groove portion has a plurality of annular groove portions and a connecting groove portion communicating with the gap and connecting the plurality of annular groove portions. The accumulator according to Appendix 10.

Explanation of Reference Numerals

[0063] 1 Cylinder body, 1a First vent hole, 1b Second vent hole, 2 Lid body, 2a Through hole, 3 Seal structure portion, 4 Fixed member, 5 Temperature detection means, 6 Seal member, 7, 8, 9 Heat insulating members, 10 Storage space, 11 Female screw portion, 20 Inner lid body, 20a Through hole, 21 Outer lid body, 21a Through hole, 22 Screw fastening portion, 23 Weld fixing portion, 24 Groove portion, 24a Annular groove portion, 24b Connecting groove portion, 100, 100A, 101, 101A, 102 Accumulator, 200 Pipe, 300 Injection pipe, 400 Discharge pipe, S Gap.

Claims

1. A pressure accumulator that vaporizes and stores cryogenic liquefied gas by injecting it from the outside through a pipe into the interior, comprising: a metal cylinder for vaporizing and storing liquefied gas in an internal storage space; a lid that forms a through-hole through which the pipe passes, fixes the pipe passed through the through-hole, and closes the open end of the cylinder with a gap communicating with the storage space of the cylinder provided between the lid and the inner peripheral surface of the cylinder; a seal structure portion provided between the outer peripheral portion of the lid and the inner peripheral portion of the cylinder to fill at least a part of the gap; a fixing member provided at the open end of the cylinder, having an outer peripheral surface screwed and fastened to the inner peripheral surface of the cylinder, and supporting and fixing the lid from the outside.

2. The lid has a screw fastening portion for fixing the pipe passed through the through-hole by screw fastening, and a seal member for closing the space therebetween is provided between the inner peripheral portion of the lid and the outer peripheral portion of the pipe. The pressure accumulator according to claim 1.

3. The lid has a welding fixing portion for fixing the pipe passed through the through-hole by welding. The pressure accumulator according to claim 1.

4. The lid is formed of austenitic stainless steel. The pressure accumulator according to any one of claims 1 to 3.

5. The pressure accumulator according to any one of claims 1 to 3, further comprising a heat insulating member provided between the lid and the fixing member.

6. The lid is formed of austenitic stainless steel and is an inner lid disposed on the storage space side of the cylinder, is formed of low alloy steel and is an outer lid disposed on the fixing member side. The pressure accumulator according to any one of claims 1 to 3.

7. Heat insulating members are provided between the inner lid and the outer lid, and between the outer lid and the pipe, respectively. The pressure accumulator according to claim 6.

8. The pressure accumulator according to any one of claims 1 to 3, further comprising temperature detecting means for detecting the temperature of the vaporized liquefied gas stored in the storage space of the cylinder or the temperature of the lid.

9. In the cylinder, a first vent hole for communicating the outside of the cylinder with the gap and injecting gas from the outside of the cylinder into the gap. A second vent hole that communicates the outside of the cylinder body with the gap and discharges the gas injected into the gap through the first vent hole to the outside of the cylinder body, and the accumulator according to any one of claims 1 to 3.

10. The lid body is formed of austenitic stainless steel and has an inner lid body disposed on the storage space side of the cylinder body, and an outer lid body formed of low alloy steel and disposed on the fixed member side. The accumulator according to claim 9, wherein a groove portion through which the gas injected into the gap circulates is formed on one or both of the end faces of the inner lid body and the outer lid body that face each other.

11. The groove portion includes a plurality of annular groove portions, The accumulator according to claim 10, further comprising a connecting groove portion that communicates with the gap and connects the plurality of annular groove portions.

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