JP2023163323A - liquefied gas tank - Google Patents

Abstract

To prevent mixing of air into a pump barrel when taking out a pump for delivery of a liquefied gas from the inside of a tank.SOLUTION: A liquefied gas tank 1 includes: a tank body 10 for storing a liquefied gas; a pump barrel 2 penetrating the tank body 10 in the vertical direction; a pump 3 installed in the tank body 10, and for delivering the liquefied gas stored in the tank body 10 through the pump barrel 2; a chamber 4 installed on a tank roof 11 so as to cover a barrel opening 2H of the pump barrel 2; a suspension device 5 installed in the chamber 4, and for suspending the pump 3 into a space 4A in the chamber through the pump barrel 2; and a gas replacement device 6 for replacing the space 4A in the chamber at least with a gas environment of the liquefied gas to be stored or into an inert gas environment.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a liquefied gas tank that stores low-temperature liquefied gas.

For example, a liquefied gas tank that stores liquefied gas such as liquefied hydrogen or liquefied natural gas needs to be attached with a pump for discharging the liquefied gas inside the tank. When discharging liquefied gas through the tank roof, a pump is installed inside the tank and sends the liquefied gas to the outside through a cylindrical pump barrel that penetrates the tank roof (for example, Patent Document 1).

For maintenance work on the pump, it may be necessary to remove the pump from the tank. In this case, the pump is lifted through the pump barrel and removed from the barrel opening at the upper end of the pump barrel.

Japanese Patent Application Publication No. 2017-132619

When removing the pump from the barrel opening, it is desirable not to introduce air into the tank through the pump barrel. In particular, when the liquefied gas stored in the tank is cryogenic liquefied hydrogen, the air that enters the barrel from the barrel opening is liquefied or solidified, which causes various problems including safety.

An object of the present disclosure is to provide a liquefied gas tank that can prevent air from entering the pump barrel when a pump for discharging liquefied gas is taken out from the tank.

A liquefied gas tank according to one aspect of the present disclosure includes a tank body that stores liquefied gas, a pump barrel that vertically penetrates the tank body, and a pump barrel that is installed in the tank body and stores the liquefied gas in the tank body. a pump discharging liquefied gas through the pump barrel; a chamber installed outside the tank body so as to cover the barrel opening at the upper end of the pump barrel; A lifting device for lifting the pump into the chamber through the pump, and a gas replacement device for replacing the inside of the chamber with at least a gas environment of stored liquefied gas or an inert gas environment.

According to the present disclosure, it is possible to provide a liquefied gas tank that can prevent air from entering the pump barrel when a pump for discharging liquefied gas is taken out from inside the tank.

FIG. 1 is a schematic diagram of the structure of a liquefied gas tank according to the present disclosure, and is a cross-sectional view of the tank main body. FIG. 2 is a diagram schematically showing the inside of a chamber installed outside the tank body.

Hereinafter, a liquefied gas tank according to an embodiment of the present disclosure will be described in detail based on the drawings. The liquefied gas tank of the present disclosure is a tank that stores low-temperature liquefied gas. The stored liquefied gas is, for example, liquefied hydrogen, liquid helium, liquid nitrogen, liquefied natural gas, liquefied petroleum gas, or liquefied ammonia. In particular, the liquefied gas tank according to the present disclosure is suitable as a tank for storing liquefied hydrogen.

[Overall structure of tank]
FIG. 1 is a schematic diagram showing the structure of a liquefied gas tank 1 according to the present disclosure. The liquefied gas tank 1 is a tank for storing cryogenic liquefied hydrogen LH, and is a ground-mounted flat-bottomed tank with a multi-shell structure. The liquefied gas tank 1 includes a tank body 10 that stores liquefied hydrogen LH, a pump barrel 2 that is a structure for discharging the liquefied hydrogen LH from the tank body 10, and a state in which the tank body 10 is immersed in the liquefied hydrogen LH. The tank includes a submersible pump 3 installed in the tank body 10, and a chamber 4 installed outside the tank body 10. In FIG. 1, a portion of the tank body 10 is shown in cross section.

The tank body 10 has a storage space that stores liquefied hydrogen LH. Although FIG. 1 shows a simple single-shell structure, the actual tank body 10 has a multi-shell structure such as a double-shell structure or a triple-shell structure. In the case of a double shell structure, the tank body 10 is composed of an outer tank installed on a foundation, an inner tank enclosed in the outer tank, and a cold insulation layer between the outer tank and the inner tank. Ru. Liquefied hydrogen LH is stored inside the inner tank. The cold insulation layer is filled with a powder heat insulating material such as granular perlite and a low boiling point gas. In the case of the triple shell structure, the tank body 10 has a structure further including an intermediate tank between the outer tank and the inner tank. In addition, the tank body 10 may be a tank having a shape other than a flat bottom, a tank buried underground, or the like.

The pump barrel 2 is a cylindrical body installed so as to vertically penetrate the tank body 10, and serves as a discharge pipe for discharging the liquefied hydrogen LH inside the tank body 10 to the outside. The pump barrel 2 has an inner barrel space 2A that is an inner space through which liquefied hydrogen LH flows, a lower end 21 that is disposed near the bottom plate of the tank body 10 and is immersed in the liquefied hydrogen LH, and a pump that penetrates the tank roof 11. and an upper end portion 22 extending upward. A portion of the upper end 22 extends into the chamber 4. The barrel interior space 2A extends vertically between the lower end 21 and the upper end 22, and has an inner diameter that allows the pump 3 to pass therethrough.

The pump 3 is housed in the barrel interior space 2A near the lower end 21. A foot valve 23 is attached to the intake opening at the lower end 21 of the pump barrel 2 . The pump 3 is placed on the foot valve 23, and as the foot valve 23 hangs down due to the weight of the pump 3, the intake opening at the lower end 21 is opened. The pump 3 takes in the liquefied hydrogen LH in the tank body 10, increases the pressure, and sends out the liquefied hydrogen LH to the barrel interior space 2A.

A discharge port 24 is provided protruding near the upper end 22 of the pump barrel 2 . The upper end of the pump barrel 2 housed in the chamber 4 is provided with a barrel opening 2H that communicates the barrel interior space 2A with the exterior space. When the liquefied gas tank 1 is in operation, the barrel opening 2H is sealed with the head plate 25. By operating the pump 3, liquefied hydrogen LH is discharged from the barrel interior space 2A through the discharge port 24.

On the other hand, during maintenance work on the pump 3, the head plate 25 is removed and the barrel opening 2H is opened. The pump 3 is lifted through the pump barrel 2 and taken out from the barrel opening 2H. The foot valve 23 rises when the weight of the pump 3 is no longer applied due to the lifting described above, and seals the intake opening in the lower end 21. When the maintenance work is finished, the pump 3 is suspended from the barrel opening 2H through the pump barrel 2 and installed on the foot valve 23. Thereafter, the barrel opening 2H is sealed with the head plate 25.

The chamber 4 is installed on the tank roof 11 at a position where the pump barrel 2 penetrates the tank body 10. The chamber 4 is installed so as to cover the barrel opening 2H at the upper end of the pump barrel 2, which is sealed with the head plate 25. Note that "covering" the barrel opening 2H means, for example, surrounding the barrel opening 2H with a space having a larger cross-sectional area than the opening area of the barrel opening 2H. In this embodiment, an example is shown in which the chamber 4 is installed so that the upper, side, and lower parts of the barrel opening 2H are located in the chamber interior space 4A, which is a closed space surrounded by the chamber 4. .

As described above, in order to take out the pump 3 installed in the tank body 10 during maintenance work or the like, it is necessary to open the barrel opening 2H. At this time, air may get mixed into the pump barrel 2. In this embodiment, since the tank body 10 stores liquefied hydrogen LH, the air (nitrogen and oxygen) that enters the pump barrel 2 is liquefied or solidified, causing various problems including safety. Therefore, in this embodiment, a chamber 4 is provided to prevent air from entering the pump barrel 2 when the pump 3 is taken out from the tank body 10. By installing the chamber 4, even if the head plate 25 is removed during maintenance work, etc., the barrel inner space 2A and the atmosphere are not directly communicated through the barrel opening 2H, and the chamber inner space 4A is interposed between the two. be able to. The detailed structure of the chamber 4 will be explained below.

[Detailed structure of chamber]
FIG. 2 is a diagram schematically showing the internal structure of the chamber 4. As shown in FIG. The chamber 4 includes a chamber main body 41 , a preliminary chamber 42 , an opening/closing door 43 (inlet portion), an inner door 44 , a pump loading/unloading port 45 , and a pump temporary storage portion 46 . A lifting device 5 for lifting the pump 3 is arranged within the chamber 4. Further, a gas replacement device 6 that can supply an inert gas to the chamber 4 is attached.

The chamber 4 is assembled on a deck 40 installed on the tank roof 11. The deck 40 is installed on the tank roof 11 so as to surround the upper end 22 of the pump barrel 2. The deck 40 includes a vertical frame 401 that is erected on the tank roof 11 and serves as a support for supporting the chamber 4, and a horizontal frame 402 that is supported by the vertical frame 401. The horizontal frame 402 is installed at a position lower than the barrel opening 2H and supports the bottom surface of the chamber 4.

The chamber body 41 defines a chamber interior space 4A that is a closed space except for an opening for inlet and exhaust of replacement gas. The shape of the chamber body 41 is not limited as long as it is installed so as to cover the barrel opening 2H and a space for working can be secured, such as a rectangular parallelepiped shape, a fan shape, a cylindrical shape, a half moon shape, or a gable roof shape. Can be set to In FIG. 2, a rectangular parallelepiped-shaped chamber body 41 is illustrated, and the chamber body 41 includes a top wall 411, an inner wall 412, an outer wall 413, a bottom wall 414, and a radial side wall 415.

The top wall 411 defines the ceiling surface of the chamber body 41, and the bottom wall 414 defines the bottom surface of the chamber body 41. The upper end 22 of the pump barrel 2 penetrates the bottom wall 414 and enters the chamber interior space 4A. FIG. 2 shows a state in which the head plate 25 is opened and the barrel opening 2H of the pump barrel 2 is open in the chamber interior space 4A. A telescopic tube 26 is fitted onto the pump barrel 2 below the bottom plate 414 . The upper end of the telescopic tube 26 is attached to the bottom plate 414, and the lower end is attached to the outer periphery of the pump barrel 2 in an airtight manner. Since the tank body 10 expands and contracts in the direction toward the tank center due to thermal contraction, a relative displacement occurs with respect to the permanently installed chamber 4. The expandable tube 26 is provided to absorb the relative displacement and ensure airtightness of the chamber interior space 4A. Note that the telescopic tube 26 may be arranged above the bottom plate 414, that is, in the chamber interior space 4A. The inner wall 412 is a side wall on the center side of the tank body 10. The outer wall 413 is a radially outer side wall of the tank body 10. The radial side wall 415 is a side wall along the radial direction of the tank body 10 and connects the edges of the inner wall 412 and the outer wall 413.

The chamber body 41 has a protrusion 41T that protrudes radially outward from the outer periphery of the tank body 10, that is, the side wall of the tank body 10. The protrusion 41T is provided to facilitate the removal of the pump 3 lifted from the tank body 10. In order to support the protruding portion 41T, the horizontal frame 402 extends radially outward from the outer periphery of the tank body 10. The outer wall 413 is located radially outward than the side wall of the tank body 10.

The side wall of the chamber body 41 is provided with an air inlet hole 416 and an exhaust hole 417. In this embodiment, an example is shown in which the intake hole 416 is provided in the inner wall 412 and the exhaust hole 417 is provided in the outer wall 413. Instead, the air intake hole 416 and the exhaust hole 417 may be provided using the top wall 411, the outer wall 413, or the radial side wall 415. The air intake hole 416 is an opening for introducing replacement gas into the chamber interior space 4A of the chamber 4. The exhaust hole 417 is an opening for exhausting the replacement gas from the chamber interior space 4A.

The auxiliary chamber 42 is installed adjacent to the inner wall 412 of the chamber body 41, and partitions the auxiliary chamber space 4B. An opening/closing door 43 is installed on the side wall of the preliminary room 42. Further, an inner door 44 is installed on the inner wall 412. The opening/closing door 43 and the inner door 44 are entrance portions that allow an operator to access the inside of the chamber body 41. The preliminary chamber 42 is disposed between the opening/closing door 43 and the chamber main body 41, and is provided so as to make it difficult for the environment of the chamber interior space 4A to communicate directly with the atmospheric environment outside the tank. During maintenance or the like, a worker opens the opening/closing door 43 to enter the preliminary chamber space 4B, and after closing the opening/closing door 43, opens the inner door 44 to enter the chamber interior space 4A of the chamber body 41. The preliminary chamber 42 is provided with a preliminary chamber inlet hole 421 and a preliminary chamber exhaust hole 422 for replacing the environment of the preliminary chamber space 4B with a predetermined replacement gas environment.

The pump loading/unloading port 45 is an opening used for loading/unloading the pump 3 into/out of the chamber 4 . The pump loading/unloading port 45 is opened in the bottom wall 414 of the chamber body 41 at the protrusion 41T. The pump loading/unloading port 45 is used when transporting the pump 3 from the chamber interior space 4A to the outside, or when transporting the pump 3 from the outside into the chamber interior space 4A. The pump loading/unloading port 45 is provided with a door that is always closed and is opened when the pump 3 is loaded/unloaded.

The pump temporary storage section 46 is a storage section that is installed inside the chamber main body 41 and temporarily holds the pump 3 lifted from inside the tank main body 10. In the present embodiment, the pump temporary storage part 46 is assembled to the bottom wall 414 and is exemplified in the form of a small chamber that can accommodate the pump 3. The lifted pump 3 is temporarily held in the pump temporary storage section 46 before being carried out from the pump loading/unloading port 45. During this time, it becomes possible to purge the liquefied hydrogen LH remaining in the pump 3. In order to promote the purging, it is desirable that the temporary pump placement section 46 be provided with an inert gas inlet and an exhaust hole. Note that the pump temporary storage section 46 may not be in the form of a small chamber, but may be a temporary storage space installed at an appropriate location within the chamber body 41.

The lifting device 5 is installed near the ceiling wall 411 inside the chamber body 41. The lifting device 5 only needs to be installed outside the tank body 10, and may be installed outside the chamber body 41, for example, above the ceiling wall 411. The lifting device 5 lifts the pump 3 that requires maintenance into the chamber interior space 4A through the pump barrel 2. Further, the lifting device 5 suspends the pump 3 after maintenance or a new pump 3 into the tank body 10 through the pump barrel 2. Further, the lifting device 5 lifts and suspends the pump 3 through the pump loading/unloading port 45.

The lifting device 5 includes a drum 51 that rotates forward and reverse around an axis, and a lifting wire 52 wound around the drum 51. The suspension wire 52 is paid out by the forward rotation of the drum 51, and the suspension wire 52 is wound up by the reversal of the drum 51. When lifting the pump 3, the lifting wire 52 is suspended into the barrel interior space 2A through the barrel opening 2H, and the tip of the lifting wire 52 is connected to the pump 3.

The lifting device 5 is installed so as to be movable vertically above the pump barrel 2 and vertically above the pump loading/unloading port 45 . A hoist rail 53 extending horizontally is installed near the ceiling wall 411 of the chamber body 41. The hoist rail 53 extends from a position above the barrel opening 2H to a position above the pump loading/unloading port 45 between the inner wall 412 and the outer wall 413 of the protrusion 41T. A movable roller 54 that holds the drum 51 is engaged with the hoist rail 53. Thereby, the drum 51 can be moved in the horizontal direction along the hoist rail 53 from above the barrel opening 2H to above the pump loading/unloading port 45. A pump temporary placement section 46 is also arranged on the path of this movement.

The gas replacement device 6 is a device that replaces the chamber interior space 4A and the preliminary interior space 4B from an air environment to a predetermined replacement gas environment. The replacement gas environment is at least a gas environment of the liquefied gas stored in the tank body 10, a hydrogen gas environment that is vaporized gas of liquefied hydrogen LH in this embodiment, or an inert gas environment. Examples of the inert gas include rare gases such as helium and nitrogen gas.

The gas replacement device 6 includes a replacement gas supply source, an air supply pump, a flow rate adjustment valve, and the like. The main air supply pipe 61 of the gas replacement device 6 is connected to the air intake hole 416 of the chamber body 41, and the preliminary chamber air supply pipe 62 is connected to the preliminary chamber air intake hole 421, respectively. During maintenance of the pump 3, hydrogen gas or helium gas is supplied from the gas replacement device 6 to the chamber interior space 4A through the main air pipe 61. The air that existed in the chamber interior space 4A before being supplied is exhausted to the outside from the exhaust hole 417. Thereby, even if the head plate 25 of the pump barrel 2 is opened to lift the pump 3, it is possible to prevent air from entering the barrel interior space 2A from the barrel opening 2H.

Note that nitrogen gas may be supplied to the chamber interior space 4A instead of helium gas. In this case, measures are taken to prevent nitrogen gas from entering the barrel interior space 2A. For example, pressure adjustment is performed such that the pressure in the chamber interior space 4A is set lower than the pressure in the barrel interior space 2A. The pressure difference based on the pressure adjustment can prevent the nitrogen gas filled in the chamber interior space 4A from entering the barrel interior space 2A.

Further, during maintenance, an inert gas such as nitrogen gas is supplied from the gas replacement device 6 to the preliminary chamber space 4B through the preliminary chamber air supply pipe 62. The air that existed in the preliminary chamber space 4B before being supplied is exhausted to the outside from the preliminary chamber exhaust hole 422. Thereby, even if the inner door 44 is opened and the airtightness of the chamber inner space 4A is released, air can be prevented from entering the chamber inner space 4A. Instead of nitrogen gas, hydrogen gas or helium gas may be supplied to the preliminary chamber space 4B.

[Pump removal work]
Next, an example of the work performed in the chamber 4 when the pump 3 is taken out during maintenance work will be briefly described. First, the gas replacement device 6 is operated to supply the above-described predetermined replacement gas to the chamber interior space 4A and the preliminary chamber space 4B. It is desirable that the replacement gas be continuously supplied during maintenance work to continue ventilation of the chamber interior space 4A and the preliminary interior space 4B. The worker is equipped with an oxygen cylinder when entering the room through the opening/closing door 43.

The operator removes the head plate 25 to open the barrel opening 2H, and takes out the hanging wire 52 stored in the pump barrel 2 near the head plate 25. One end of the hanging wire 52 is attached to the lifting device 5. Note that one end of the hanging wire 52 and the other end are attached to the pump 3 in advance. Subsequently, the operator operates the lifting device 5 to wind the lifting wire 52 around the drum 51. By this operation, the pump 3 installed at the lower end 21 of the pump barrel 2 is lifted into the chamber interior space 4A through the barrel interior space 2A. Thereafter, the barrel opening 2H is closed by the head plate 25.

Next, the operator operates the hoist drive device to move the drum 51 with the pump 3 suspended along the hoist rail 53 and position it above the pump temporary storage section 46 . Then, the pump 3 is lowered and stored in the pump temporary storage section 46. After the pump 3 is held in the pump temporary storage part 46 for a predetermined purge time, the drum 51 is caused to perform a winding operation of the hanging wire 52 to lift the pump 3 again. Subsequently, the drum 51 is moved along the hoist rail 53 to above the pump loading/unloading port 45 .

After that, the pump loading/unloading port 45 is opened. Then, the suspended pump 3 is lowered by letting out the wire 52 from the drum 51, and the pump 3 is carried out of the chamber main body 41 from the pump carry-in/out port 45, as shown by the dotted line in FIG. Since the pump loading/unloading port 45 is opened in the protrusion 41T, the pump 3 can be brought into contact with the ground or the loading platform of a recovery vehicle by simply lowering the pump 3. After the lowering is completed, the suspension wire 52 is removed from the pump 3 and the pump 3 is recovered. When installing the pump 3 after maintenance or a new pump 3 into the tank body 10, the operation opposite to the above is performed.

According to the liquefied gas tank 1 according to the present embodiment described above, the chamber interior space 4A of the chamber 4 installed so as to cover the barrel opening 2H corresponds to the stored liquefied hydrogen by the gas replacement device 6. It can be replaced with a hydrogen gas environment or an inert gas environment. Further, the lifting device 5 lifts the pump 3 through the pump barrel 2 into the chamber interior space 4A. Therefore, the pump 3 inside the tank body 10 can be taken out of the tank body 10 without exposing the barrel opening 2H to air. Therefore, air present around the tank body 10 can be prevented from entering the pump barrel 2.

[Modified example]
Although the embodiments of the present invention have been described above, the present invention is not limited to these, and can take, for example, the following modified embodiments.

(1) In order to simplify the chamber 4, the preliminary chamber 42 and pump temporary storage section 46 may be omitted. On the contrary, the preliminary chamber 42 is arranged in two stages, and one preliminary chamber is used as a space for replacing air with nitrogen gas, and the other preliminary chamber near the chamber body 41 is used as a space for replacing nitrogen gas with hydrogen gas or helium gas. It may also be a mode.

(2) In the above embodiment, a mode in which the lifted pump 3 is moved along the hoist rail 53 is illustrated. Instead, a first lifting device for lifting and lowering the pump 3 through the pump barrel 2 and a second lifting device for lifting and lowering the pump 3 through the pump loading/unloading port 45 are installed in the chamber body 41, and both The movement of the pump 3 between devices may be performed by a transport device such as a moving cart or a transport robot.

(3) In the above embodiment, an example is shown in which the chamber main body 41 is provided with the protrusion 41T, and the pump loading/unloading port 45 is opened in the bottom wall 414 of the protrusion 41T. Instead of providing the protruding portion 41T, an opening for carrying out the pump 3 may be provided in the radial side wall 415 or the ceiling wall 411, and the pump 3 may be lowered to the ground using a crane or the like installed outside.

[Summary of this disclosure]
The specific embodiments described above include disclosures having the following configurations.

A liquefied gas tank according to a first aspect of the present disclosure includes a tank body that stores liquefied gas, a pump barrel that vertically penetrates the tank body, and a pump barrel that is installed in the tank body and stores the liquefied gas in the tank body. a pump for discharging the liquefied gas through the pump barrel; a chamber installed outside the tank body so as to cover the barrel opening at the upper end of the pump barrel; The pump includes a lifting device that lifts the pump into the chamber through a pump barrel, and a gas replacement device that replaces the inside of the chamber with at least a gas environment of stored liquefied gas or an inert gas environment.

According to this liquefied gas tank, the inside of the chamber installed to cover the barrel opening can be replaced by a gas environment of the stored liquefied gas or an inert gas environment by the gas replacement device. A lifting device also lifts the pump into the chamber through the pump barrel. Therefore, it is possible to take out the pump inside the tank body to the outside of the tank body without exposing the barrel opening to air. Therefore, air present around the tank body can be prevented from entering the pump barrel.

The liquefied gas tank according to a second aspect is the liquefied gas tank according to the first aspect, wherein the chamber includes a protrusion that protrudes radially outward from the outer periphery of the tank body, and the protrusion allows the pump to A pump carry-in/out port is provided for carrying the chamber from the inside to the outside or carrying it into the chamber from the outside.

According to the second aspect, the pump lifted from within the tank body can be carried out from the chamber through the pump carry-in/out port, or a new pump or a pump after maintenance can be carried into the chamber from the outside. . Furthermore, since the pump loading/unloading port is provided in the protrusion of the chamber, the pump can be loaded/unloaded into/out of the chamber using a simple lifting device.

The liquefied gas tank according to the third aspect is the liquefied gas tank according to the first or second aspect, wherein the pump temporary holding part is installed in the chamber and temporarily holds the pump lifted from within the tank main body. Furthermore, it is equipped with.

According to the third aspect, the suspended pump can be temporarily held in the chamber by using the pump temporary placement part. Therefore, for example, while the pump is being temporarily placed in the pump temporary placement part, it is possible to purge the liquefied gas remaining in the pump.

In the liquefied gas tank according to a fourth aspect, in the liquefied gas tank according to any one of the first to third aspects, the chamber is installed on the roof of the tank body, and the side wall of the chamber on the center side of the tank body Alternatively, an inlet portion is provided that allows access into the chamber from a side wall along the radial direction of the tank body.

According to the fourth aspect, the inlet portion is provided on the side wall on the center side or the side wall along the radial direction of the tank body, so that a worker etc. can easily enter the chamber from the roof of the tank body through the inlet portion. You can come in and out.

The liquefied gas tank according to a fifth aspect is the liquefied gas tank according to the fourth aspect, further comprising a preliminary chamber installed between the inlet section and the chamber.

According to the fifth aspect, the provision of the preliminary chamber makes it possible to create a structure in which it is difficult for the chamber internal space to communicate directly with the atmosphere when opening and closing the inlet. Therefore, it is easy to restrict the entry of air into the chamber.

The liquefied gas tank according to a sixth aspect is the liquefied gas tank according to the fifth aspect, in which the gas replacement device mutually replaces the interior of the preliminary chamber with at least an inert gas environment or an atmospheric environment.

According to the sixth aspect, for example, the preliminary chamber can be replaced with an inert gas environment before the inlet is opened, and air can be prevented from flowing into the chamber from the preliminary chamber.

LH Liquid hydrogen (liquefied gas)
1 Liquefied gas tank 10 Tank body 2 Pump barrel 2A Barrel interior space 2H Barrel opening 3 Pump 4 Chamber 4A Chamber interior space 4B Reserve interior space 41 Chamber body (chamber)
41T Projection 412 Inner wall (side wall on the center side of the tank body)
42 Spare room 43 Opening/closing door (entrance)
44 Inner door 45 Pump import/exit 46 Pump temporary storage section 5 Lifting device 6 Gas replacement device

Claims (6)

A tank body that stores liquefied gas,
a pump barrel that vertically penetrates the tank body;
a pump installed in the tank body and discharging the liquefied gas stored in the tank body through the pump barrel;
a chamber installed outside the tank body so as to cover the barrel opening at the upper end of the pump barrel;
a lifting device installed outside the tank body and lifting the pump into the chamber through the pump barrel;
a gas replacement device that replaces the inside of the chamber with at least a stored liquefied gas gas environment or an inert gas environment;
A liquefied gas tank with The liquefied gas tank according to claim 1,
The chamber includes a protrusion that protrudes radially outward from the outer periphery of the tank body,
The protruding portion is a liquefied gas tank, wherein the protrusion includes a pump carry-in/out port for carrying the pump from inside the chamber to the outside or carrying it into the chamber from the outside. The liquefied gas tank according to claim 1,
A liquefied gas tank, further comprising a pump temporary holding part installed in the chamber and temporarily holding the pump lifted from the tank main body. The liquefied gas tank according to any one of claims 1 to 3,
The chamber is installed on the roof of the tank body,
A liquefied gas tank, comprising: an inlet portion that allows access into the chamber from a side wall on the center side of the tank body in the chamber or a side wall along the radial direction of the tank body. The liquefied gas tank according to claim 4,
The liquefied gas tank further includes a preliminary chamber installed between the inlet section and the chamber. The liquefied gas tank according to claim 5,
The gas replacement device is a liquefied gas tank that mutually replaces the interior of the preliminary chamber with at least an inert gas environment or an atmospheric environment.

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