Transfer method and transfer facility for liquefied hydrogen

Abstract

To shorten a time required for removing air from a pipe that transfers liquefied hydrogen, and reduce an amount of purge gas used.SOLUTION: A method is provided for transferring liquefied hydrogen from a liquefied hydrogen transfer source 11 to a liquefied hydrogen transfer destination 12 using a transfer pipe 10. First, a terminal of a first pipe 13 extending from the liquefied hydrogen transfer source 11 is connected to a terminal of a second pipe 14 extending from the liquefied hydrogen transfer destination 12 in an environment where air is present, while being isolated from the interiors of the first pipe 13 and the second pipe 14, to form a pipe connection part 2. Next, the air present inside the pipe connection part 2 is introduced into a recovery part 4 incorporated in the second pipe 14, together with liquefied hydrogen supplied from the first pipe 13. In the recovery part 4, solid matter SB generated from the air in the pipe connection part 2 is recovered.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a method and transfer equipment for transferring liquefied hydrogen from a source of transfer of the liquefied hydrogen to a destination of the liquefied hydrogen using piping. [Background technology]

[0002] For example, liquefied hydrogen needs to be transferred from a liquefied hydrogen storage tank to a liquefied hydrogen carrier in facilities that handle liquefied hydrogen. During transfer, the source and destination are connected by a transfer pipe, and the liquefied hydrogen is transferred through the transfer pipe. Liquefied hydrogen has an extremely low temperature of -253°C, and even solidifies air (nitrogen and oxygen). For this reason, purging is required before the transfer of liquefied hydrogen to remove gases other than hydrogen that are present in the transfer pipe and to prevent the solidified gases that come into contact with the liquefied hydrogen from causing pipe clogging, etc.

[0003] As the purging operation, a pressure swing method is known (Patent Document 1). When purging air remaining in a transfer piping, in the pressure swing method, a pressurizing operation of supplying a purge gas to the transfer piping and a depressurizing operation of discharging the gas in the transfer piping are repeated. In the case of a transfer piping for liquefied hydrogen, the air in the transfer piping is replaced with nitrogen gas, and then the purging operation of replacing the nitrogen gas with hydrogen gas is performed by the pressure swing method. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-19552 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, with the pressure swing method, the gas in the transfer piping cannot be removed to a level that does not pose a problem unless the pressurization and depressurization operations are repeated a considerable number of times. In the case of liquefied hydrogen transfer piping, in both the nitrogen gas replacement and hydrogen gas replacement described above, the pressurization and depressurization operations must be repeated several dozens of times, which requires a long operation time and a large amount of purge gas.

[0006] An object of the present disclosure is to provide a method and equipment for transferring liquefied hydrogen that can shorten the time required for air removal from piping used to transfer liquefied hydrogen and reduce the amount of purge gas used. [Means for solving the problem]

[0007] A method for transferring liquefied hydrogen according to one aspect of the present disclosure is a method for transferring liquefied hydrogen from a source to a destination using piping, comprising: connecting an end of a first piping extending from the source to an end of a second piping extending from the destination in an air-present environment while being isolated from the interiors of the first piping and the second piping to form a piping connection; introducing the air present inside the piping connection together with liquefied hydrogen supplied from the first piping into a recovery section incorporated in the second piping; and recovering solids generated from the air in the piping connection section in the recovery section.

[0008] A liquefied hydrogen transfer equipment according to another aspect of the present disclosure is a liquefied hydrogen transfer equipment that transfers liquefied hydrogen through a first piping extending from a source of liquefied hydrogen, and includes a transfer piping including a second piping extending from a destination of the liquefied hydrogen and a piping connection part connecting an end of the first piping and an end of the second piping, a cut-off structure part that can seal the end of the first piping and the end of the second piping to cut off the piping connection part from the first piping and the second piping, and can release the seal to cut off the piping connection part from the first piping and the second piping, and a recovery part that is arranged in the second piping downstream of the cut-off structure part and recovers solid matter generated from the air present inside the piping connection part. Effect of the Invention

[0009] According to the present disclosure, it is possible to provide a method and equipment for transferring liquefied hydrogen that can shorten the time required for air removal from piping used to transfer liquefied hydrogen and reduce the amount of purge gas used. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram that shows a schematic diagram of a transfer facility according to a first embodiment, to which the liquefied hydrogen transfer method of the present disclosure is applied. [Diagram 2] FIG. 2 is a diagram showing a state in which solid matter is collected in the transfer facility of FIG. [Diagram 3] 3(A) to (D) are diagrams showing the steps of a conventional method for purging air from a pipe connection. [Figure 4] FIG. 4 is a diagram showing a configuration of a transfer facility according to the second embodiment. [Diagram 5] FIG. 5 is a diagram showing a solid matter recovery process when piping is connected in the transfer facility of the second embodiment. [Figure 6] FIG. 6 is a diagram showing a transfer route switching process in the transfer facility of the second embodiment. [Figure 7] FIG. 7 is a diagram showing a solid matter vaporization and exhaust process in the transfer facility of the second embodiment. [Figure 8] FIG. 8 is a diagram showing a standby state until the next pipe connection in the transfer facility of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, with reference to the drawings, an embodiment of the liquefied hydrogen transfer method and transfer equipment according to the present disclosure will be described in detail. The liquefied hydrogen transfer method and transfer equipment according to the present disclosure can be applied to various facilities that handle liquefied hydrogen. For example, the transfer method and transfer equipment according to the present disclosure can be applied to the transfer of liquefied hydrogen using piping between a loading terminal equipped with a liquefied hydrogen storage tank or the like and a ship such as a liquefied hydrogen carrier ship or a hydrogen fuel ship, between a liquefied hydrogen bunkering ship and a supply ship, between a hydrogen station and a tanker truck, etc.

[0012] [First embodiment] 1 is a schematic diagram of a liquefied hydrogen transfer facility 1 according to a first embodiment to which the liquefied hydrogen transfer method of the present disclosure is applied. The liquefied hydrogen transfer facility 1 is a facility for transferring liquefied hydrogen from a liquefied hydrogen transfer source 11 to a liquefied hydrogen transfer destination 12 using a transfer piping 10. In the above example, the liquefied hydrogen transfer source 11 is a loading terminal when loading liquefied hydrogen, a hydrogen carrier when unloading, a bunkering ship, a hydrogen station, etc. The liquefied hydrogen transfer destination 12 is a loading terminal when unloading liquefied hydrogen, a hydrogen carrier when loading, a bunkering ship, a tanker, etc.

[0013] The liquefied hydrogen transfer facility 1 includes a transfer pipe 10, an isolation structure 3, and a recovery section 4. The transfer pipe 10 connects a liquefied hydrogen transfer source 11 and a liquefied hydrogen transfer destination 12, and is a pipe for transferring liquefied hydrogen from the liquefied hydrogen transfer source 11 to the liquefied hydrogen transfer destination 12. The transfer pipe 10 is mostly composed of a vacuum double pipe to ensure thermal insulation. The transfer pipe 10 includes a first pipe 13 extending from the liquefied hydrogen transfer source 11, a second pipe 14 extending from the liquefied hydrogen transfer destination 12, and a pipe connection section 2 disposed between the two pipes 13, 14. The isolation structure 3 includes a first valve 31 disposed between the first pipe 13 and the pipe connection section 2, and a second valve 32 disposed between the pipe connection section 2 and the second pipe 14.

[0014] The pipe connection section 2 is a pipe that connects the end of the first pipe 13 and the end of the second pipe 14. The pipe connection section 2 includes a first connection pipe 21 that extends the end of the first pipe 13, and a second connection pipe 22 that extends the end of the second pipe 14. One end of the first connection pipe 21 is connected to the end of the first pipe 13 via a first valve 31. A first flange 23 is attached to the other end of the first connection pipe 21. One end of the second connection pipe 22 is connected to the end of the second pipe 14 via a second valve 32. A second flange 24 is attached to the other end of the second connection pipe 22. By connecting the first flange 23 and the second flange 24, the first connection pipe 21 and the second connection pipe 22 are in a communication state, and it is possible to thereby make the first pipe 13 and the second pipe 14 in a communication state.

[0015] The edge-disconnecting structure 3 makes it possible to set the pipe connection part 2 to an edge-disconnected state from the first pipe 13 and the second pipe 14, and conversely, to set the pipe connection part 2 to a communication state from the first pipe 13 to the second pipe 14. When the edge-disconnected state is set, the first valve 31 and the second valve 32 are closed, and the end of the first pipe 13 and the end of the second pipe 14 are sealed. On the other hand, when the communication state is set, the first valve 31 and the second valve 32 are opened, and the sealing is released.

[0016] The disconnected state is a state that is taken when forming the pipe connection 2 before starting the transfer of liquefied hydrogen from the liquefied hydrogen transfer source 11 to the liquefied hydrogen transfer destination 12, or during downtime when no liquefied hydrogen transfer is being performed. The work of forming the pipe connection 2 is solely the work of connecting the first flange 23 and the second flange 24, and is generally performed in an environment where air is present, such as outdoors. The connected state is a state that is taken when liquefied hydrogen is actually being transferred from the liquefied hydrogen transfer source 11 to the liquefied hydrogen transfer destination 12 using the transfer piping 10.

[0017] The recovery section 4 is a housing incorporated in the second piping 14 downstream of the edge separation structure 3, and recovers solid matter generated from the air present inside the piping connection section 2. Most of the solid matter is solidified oxygen and nitrogen generated when the air inside the piping connection section 2 comes into contact with the cryogenic liquefied hydrogen sent from the first piping 13.

[0018] The collection section 4 includes a filter 41 that traps the solid matter. The filter 41 is installed in the housing of the collection section 4 so that all fluids flowing through the second pipe 14 pass through the filter 41. In other words, the filter 41 is disposed so that all fluids introduced into the collection section 4 pass through the filter 41 before moving downstream from the collection section 4. As the filter 41, for example, a wire mesh filter having a predetermined mesh size made of a metal that does not become brittle even at extremely low temperatures, a punched metal having an air vent, or the like can be used. The solid matter generated from the air in the pipe connection section 2 is collected by the filter 41, and the solid matter can be prevented from moving downstream of the second pipe 14.

[0019] The collection section 4 is incorporated in the second pipe 14 at a position close to the edge separation structure section 3. "Close position" means a position within the area leading to other piping equipment such as a valve body and a branch pipe downstream of the second valve 32. This allows the solid matter to be removed before it enters other piping equipment, and various troubles such as pipe clogging can be prevented. In order to shorten the section in which the solid matter flows through the second pipe 14 as much as possible, it is desirable to install the collection section 4 immediately downstream of the second valve 32. This allows the solid matter generated at the pipe connection section 2 in the edge separation structure section 3 to be immediately collected by the collection section 4 before it is broken down and dispersed.

[0020] A method for transferring liquefied hydrogen using the liquefied hydrogen transfer facility 1 of the first embodiment configured as described above will be described. FIG. 1 is also a diagram showing a process for forming the pipe connection section 2, which is performed before starting the transfer of liquefied hydrogen through the transfer pipe 10. In this process, the first valve 31 and the second valve 32 are closed. That is, the pipe connection section 2 is isolated from the inside of the first pipe 13 and the second pipe 14 by the isolation structure section 3. The inside of the sealed first pipe 13 and the second pipe 14 is filled with liquefied hydrogen (LH2) or a two-phase fluid of liquefied hydrogen and its boil-off gas. The inside of the recovery section 4 incorporated in the second pipe 14 is the same.

[0021] In the above-described disconnected state, the pipe connection part 2 is formed. That is, the first connection pipe 21 and the second connection pipe 22 are in a communicated state by connecting the first flange 23 and the second flange 24. The above connection is generally performed as outdoor work in the presence of air, and no particular inert gas work environment is created or purging is performed. Therefore, the inside of the pipe connection part 2 is in a state where air is trapped inside.

[0022] Next, as shown in Fig. 2, the isolation provided by the isolation structure 3 is released, allowing liquefied hydrogen to flow into the pipe connection section 2. Fig. 2 is a diagram showing a state in which both the first valve 31 and the second valve 32 of the isolation structure 3 are opened, allowing liquefied hydrogen (LH2) to flow through the transfer pipe 10. By the above valve operation, the air present inside the pipe connection section 2 is introduced into the recovery section 4 incorporated in the second pipe 14, together with the liquefied hydrogen supplied from the first pipe 13.

[0023] The air present in the pipe connection part 2 is instantly solidified by contact with the cryogenic liquefied hydrogen at -253°C and quenched, becoming solid matter SB. The solid matter SB is transferred to the recovery part 4 together with the liquefied hydrogen as the fluid flows in the transfer pipe 10. In the recovery part 4, the liquefied hydrogen passes through the filter 41 and flows downstream of the second pipe 14, but the solid matter SB is trapped by the filter 41. In other words, the solid matter SB generated from the air in the pipe connection part 2 is recovered in the recovery part 4. Therefore, the solid matter SB can be prevented from entering the piping equipment arranged in the transfer pipe 10 downstream of the recovery part 4.

[0024] In general, contact between air and liquefied hydrogen should be avoided as much as possible. However, explosion-proofing can be ensured if certain conditions are met. Hydrogen can ignite in the air at a concentration range of 4% to 75%. In other words, in a closed space such as inside a pipe, even if a small amount of air comes into contact with a large amount of liquefied hydrogen, the possibility of ignition is extremely low. Residual air at the pipe connection 2 instantly becomes a solid SB, and since there are no ignition sources, including static electricity, in an environment where liquefied hydrogen dominates, ignition of oxygen can be prevented.

[0025] According to the first embodiment described above, since the edge separation structure 3 is provided, the pipe connection section 2 that connects the first pipe 13 and the second pipe 14 can be constructed in an easy working environment exposed to the outside air. After that, the edge separation by the edge separation structure 3 is released, and the air present in the pipe connection section 2 is intentionally brought into contact with the liquefied hydrogen supplied from the first pipe 13 to create an environment in which the air can be solidified. That is, a recovery section 4 having a filter 41 is disposed downstream of the edge separation structure 3, and the air in the pipe connection section 2 is sent to the recovery section 4 in a state in which it is in contact with the liquefied hydrogen supplied from the first pipe. Then, the solid matter SB generated from the air by contact with the liquefied hydrogen is recovered in the recovery section 4.

[0026] That is, in this embodiment, the phenomenon that liquefied hydrogen solidifies almost all substances is taken advantage of to solidify the air (mainly oxygen and nitrogen) in the pipe connection part 2, and this is collected in the collection part 4. Therefore, the work of removing the air can be completed in an extremely short time. Of course, since the solid matter SB is collected by the filter 41 and is not directed downstream of the collection part 4, problems such as pipe clogging in the second pipe 14 can be suppressed. Also, since there is no process of replacing the air in the pipe connection part 2 with a purge gas, the amounts of nitrogen gas and hydrogen gas used as purge gas can be significantly reduced.

[0027] [Comparative example / Explanation of the pressure swing method] For comparison with the first embodiment described above, the pressure swing method, which has been conventionally used as a purging operation for removing air from a pipe connection, will be described. Figures 3(A) to 3(D) are diagrams showing the procedure for air purging using the pressure swing method. A purging port 25 is provided in the pipe connection 20 that connects the first pipe 13 and the second pipe 14.

[0028] 3(A), the pipe connection 20 is formed with the first valve 31 and the second valve 32 closed. At this time, the first pipe 13 and the second pipe 14 are filled with liquefied hydrogen (LH2), but air is present inside the disconnected pipe connection 20. In the pressure swing method, a pressurizing operation of injecting replacement gas into the pipe connection 20 from the port 25 and a depressurizing operation of depressurizing the pipe connection 20 and discharging the gas from the port 25 are repeated several tens of times.

[0029] First, a purging operation is performed to replace the air in the pipe connection part 20 with nitrogen gas (N2). Specifically, as shown in FIG. 3(A), the operation of pressurizing nitrogen gas through the port 25 and then exhausting the nitrogen gas and air from the port 25 is repeated. After the pipe connection part 20 is replaced with nitrogen gas, the pressurizing of hydrogen gas through the port 25 and the exhausting of hydrogen gas and nitrogen gas from the port 25 are repeated as shown in FIG. 3(B) to replace the air in the pipe connection part 20 with hydrogen gas (H2). After the pipe connection part 20 is replaced with hydrogen gas, the port 25 is closed as shown in FIG. 3(C). Thereafter, as shown in FIG. 3(D), the first valve 31 and the second valve 32 are opened, and the transfer of liquefied hydrogen from the first pipe 13 to the second pipe 14 through the pipe connection part 20 is started.

[0030] In the pressure swing method, the gas in the pipe connection part 20 is gradually replaced by the self-diffusion of nitrogen gas or hydrogen gas. Therefore, purging the pipe connection part 20 requires a very long time due to the repeated pressurization and depressurization operations, and also requires a large amount of nitrogen gas and hydrogen gas. In contrast, according to the present embodiment, the air in the pipe connection part 2 is expelled to the recovery part 4 in one go, so the work time for air removal can be significantly shortened compared to the pressure swing method. In addition, since there is no process of replacing the air in the pipe connection part 2 with a purge gas, there are advantages that purging equipment is not required and the amount of nitrogen gas and hydrogen gas used as purge gas can be significantly reduced.

[0031] [Second embodiment] Next, a second embodiment of the present disclosure will be described with reference to Figs. 4 to 8. In the second embodiment, an example is shown in which a third pipe (main pipe 141 described below) capable of transferring liquefied hydrogen without passing through the recovery section 4 is set in the second pipe 14. After the solid matter SB is recovered in the recovery section 4, the liquefied hydrogen is transferred through the third pipe. In other words, the recovery section 4 is separated from the transfer path of the liquefied hydrogen. Therefore, the solid matter SB recovered in the recovery section 4 can be easily treated.

[0032] 4 is a diagram showing the configuration of a liquefied hydrogen transfer facility 1A according to the second embodiment. The liquefied hydrogen transfer facility 1A is a facility for transferring liquefied hydrogen from a liquefied hydrogen transfer source 11 to a liquefied hydrogen transfer destination 12 using a transfer piping 10. The liquefied hydrogen transfer facility 1A includes a transfer piping 10, an isolation structure unit 3, and a recovery unit 4, similar to the first embodiment. In addition to these, the liquefied hydrogen transfer facility 1A includes a purge piping 5 for purging the recovery unit 4.

[0033] The transfer pipe 10 includes a second pipe 14 extending from the liquefied hydrogen transfer destination 12, and a pipe connection part 2 disposed between the two pipes 13, 14. The edge separation structure part 3 includes a first valve 31 disposed between the first pipe 13 and the pipe connection part 2, and a second valve 32 disposed between the pipe connection part 2 and the second pipe 14. The pipe connection part 2 includes a first connection pipe 21 having one end connected to the first valve 31 and a first flange 23 at the other end, and a second connection pipe 22 having one end connected to the second valve 32 and a second flange 24 at the other end. These are the same as those in the first embodiment, so the description will be omitted. However, the configuration is different from that of the first embodiment in that the second valve 32 is a three-way valve.

[0034] In the second pipe 14, a third valve 33 is disposed downstream of the second valve 32. The third valve 33 is also a three-way valve. The second pipe 14 includes a main pipe 141 (third pipe) and a bypass pipe 142 disposed in parallel between the second valve 32 and the third valve 33, and a main pipe 140 disposed downstream of the junction of these pipes. The bypass pipe 142 incorporates a recovery section 4 equipped with a filter 41 capable of trapping solidified matter in the air. That is, the bypass pipe 142 is a pipe that passes through the recovery section 4. On the other hand, the main pipe 141 is a pipe that short-circuits between the second valve 32 and the third valve 33. That is, the main pipe 141 is a branch pipe from the second valve 32 in the second pipe 14, and is a pipe that bypasses the recovery section 4 and merges with the main pipe 140.

[0035] The purge pipe 5 is a pipe that connects the purge gas supply source 53 and the vent stack 54 through the collection unit 4. The purge pipe 5 includes a supply pipe 51 for supplying purge gas to the housing of the collection unit 4, and a discharge pipe 52 for discharging the purge gas from the housing. To open and close these pipes, the supply pipe 51 is equipped with a fourth valve 34, and the discharge pipe 52 is equipped with a fifth valve 35. The purge gas supply source 53 includes a tank or cylinder that stores a room temperature purge gas, such as nitrogen gas or hydrogen gas, and a pump that pressure-feeds the purge gas. The vent stack 54 is a facility that dilutes or renders harmless the purged gas and releases it into the atmosphere.

[0036] A method for transferring liquefied hydrogen using the liquefied hydrogen transfer facility 1A of the second embodiment configured as described above will be described with reference to Figs. 5 to 8. The procedure of the transfer method is as follows: A process for recovering solid matter when connecting pipes: a process for forming a pipe connection part 2 and recovering solid matter SB generated from the air at the pipe connection part 2 (FIG. 5); A step of switching the transfer path: a step of switching the transfer path of the liquefied hydrogen from the bypass pipe 142 to the main pipe 141 (FIG. 6); Solid matter vaporization and exhaust process: a process of vaporizing the solid matter SB collected in the collection section 4 and exhausting it to the outside air (FIG. 7); and A step of forming a standby state: after the transfer of liquefied hydrogen, the pipe connection part 2 is released and the system waits for the transfer of the next liquefied hydrogen (FIG. 8). Each step will be described in detail below.

[0037] <Solid collection process when connecting pipes> FIG. 5 is a diagram showing the implementation status of the solid matter recovery process when the piping is connected. In the display of the first valve 31 to the fifth valve 35 in FIG. 5 to FIG. 8, the valves in white indicate the "open" state, and the valves in black indicate the "closed" state. In this process, the work of forming the piping connection part 2 is first performed. As described above, this work is a work for connecting the first pipe 13 and the second pipe 14, and for the purpose of making it possible to transfer liquefied hydrogen from the liquefied hydrogen transfer source 11 to the liquefied hydrogen transfer destination 12 through the transfer pipe 10. The specific work is a work of connecting the first flange 23 of the first connection pipe 21 and the second flange 24 of the second connection pipe 22. In addition, at the time of this connection work, unlike the display in FIG. 5, the first valve 31 and the second valve 32 are closed, and the piping connection part 2 is in a disconnected state.

[0038] Next, liquefied hydrogen is introduced into the pipe connection section 2, and solid matter SB generated from the air present in the pipe connection section 2 is collected. This operation involves operating the first valve 31 to the fifth valve 35. Specifically, the first valve 31 is operated to be "open", and the second valve 32 and the third valve 33, which are three-way valves, are each operated to be "open" through the bypass pipe 142 in which the collection section 4 is arranged. The fourth valve 34 and the fifth valve 35 are "closed". The bypass pipe 142 and the collection section 4 are previously filled with a hydrogen gas atmosphere or liquefied hydrogen. The main pipe 141, which is in a disconnected state here, is also filled with hydrogen gas or liquefied hydrogen.

[0039] By the above valve operation, liquefied hydrogen flows from the first pipe 13 into the pipe connection section 2. Then, as shown by arrow A1, the air that was present in the pipe connection section 2 and the liquefied hydrogen that has flowed in flow into the recovery section 4 through the upstream side of the bypass pipe 142. The air in the pipe connection section 2 is instantly solidified by contact with the liquefied hydrogen that has flowed in, and becomes solid matter SB of oxygen and nitrogen. This solid matter SB is collected by the filter 41 of the recovery section 4. Meanwhile, the liquefied hydrogen passes through the filter 41 as shown by arrow A2. Then, as shown by arrow A3, the liquefied hydrogen enters the main pipe 140 via the downstream side of the bypass pipe 142 and the third valve 33, and is transferred to the liquefied hydrogen transfer destination 12. In other words, liquefied hydrogen that does not contain the solid matter SB is sent to the liquefied hydrogen transfer destination 12.

[0040] <Transportation route switching process> 6 is a diagram showing the implementation status of the transfer path switching step. In this step, valve operation is performed to switch the transfer path of liquefied hydrogen from the bypass piping 142 to the main piping 141. The first valve 31 is maintained in the "open" state, and the fourth valve 34 and the fifth valve 35 are maintained in the "closed" state. Meanwhile, the second valve 32 and the third valve 33 of the three-way valve are each operated so that the path through the main piping 141 that bypasses the recovery section 4 is "open."

[0041] By the above valve operation, the bypass piping 142 and the recovery section 4 are separated from the liquefied hydrogen transfer path. That is, as shown by arrows A4 and A5 in Fig. 6, the liquefied hydrogen supplied from the first piping 13 passes from the piping connection section 2 through the main piping 141 into the main piping 140 and is transferred to the liquefied hydrogen transfer destination 12. No fluid flow occurs in the bypass piping 142 and the recovery section 4, and the state in which the solid matter SB is collected in the filter 41 of the recovery section 4 is maintained.

[0042] <Solid matter vaporization and exhaust process> 7 is a diagram showing the implementation status of the solid matter vaporization and exhaust process. In this process, while liquefied hydrogen is being transferred using the main pipe 141, a purge gas is supplied to the recovery section 4 which has recovered the solid matter SB, and the solid matter SB is removed from the recovery section 4. The first valve 31, the second valve 32, and the third valve 33 are not operated, and the state of the previous process is maintained. As a result, the transfer of liquefied hydrogen from the pipe connection section 2 through the main pipe 141 continues as indicated by arrows A4 and A5.

[0043] In this embodiment, the removal of the solid material SB is performed by supplying a room temperature purge gas to the recovery section 4 and vaporizing the solid material SB. The solid material SB is mainly solidified nitrogen and oxygen, and can be vaporized by contacting the solid material SB with a gas that exceeds the melting point of the solid material SB. By contacting the solid material SB with a room temperature gas, vaporization is possible in a short time.

[0044] The purge gas supply source 53 is a supply source having a function of pumping a room temperature purge gas such as hydrogen gas or nitrogen gas. In order to introduce the room temperature purge gas into the collection section 4 and to exhaust the purged gas from the collection section 4, the fourth valve 34 and the fifth valve 35, which were "closed" in the previous process, are opened. By this valve operation, the room temperature purge gas is supplied from the purge gas supply source 53 through the supply pipe 51 to the collection section 4, as shown by the arrow A6.

[0045] The solid matter SB trapped in the filter 41 in the collection section 4 is immediately vaporized and loses its solidity upon contact with the room temperature purge gas. The vaporized gas of the solid matter SB passes through the filter 41 and moves downstream. Therefore, as shown by arrow A7, the purge gas and the vaporized gas of the solid matter SB are transported to the vent stack 54 through the exhaust pipe 52. Then, as shown by arrow A8, these gases are dissipated from the vent stack 54 into the atmosphere. In this way, the solid matter SB can be restored to harmless air and disposed of simply by supplying room temperature purge gas to the collection section 4 and exchanging heat with the solid matter SB.

[0046] <Step of forming a standby state> FIG. 8 is a diagram showing the implementation status of the step of forming the standby state. Here, a case is shown in which hydrogen gas is used as the purge gas for the recovery section 4 in the previous step. When the transfer of the planned amount of liquefied hydrogen from the liquefied hydrogen transfer source 11 to the liquefied hydrogen transfer destination 12 is completed, the first valve 31 is closed, and the second valve 32 and the third valve 33 of the three-way valve are also fully closed. This valve operation results in the main pipe 141 being filled with liquefied hydrogen and its boil-off gas. After that, the pipe connection section 2 is dismantled. Specifically, the engagement between the first flange 23 and the second flange 24 is released, and the first connection pipe 21 and the second connection pipe 22 are separated.

[0047] When the purging of the recovery section 4 is completed, the fourth valve 34 and the fifth valve 35 on the purge pipe 5 are closed. Since the second valve 32 and the third valve 33 are also fully closed, the recovery section 4 and the bypass pipe 142 are sealed in a state filled with hydrogen gas used as a purge gas. By leaving the recovery section 4 and the bypass pipe 142 in a state in which hydrogen gas is sealed, it is not necessary to purge the recovery section 4 and the bypass pipe 142 when forming the pipe connection section 2 for the next transfer of liquefied hydrogen from the liquefied hydrogen transfer source 11 to the liquefied hydrogen transfer destination 12. Therefore, the workability of the setup work for the transfer of liquefied hydrogen can be improved.

[0048] [Variations] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to these embodiments. For example, the following modified embodiments are possible.

[0049] (1) In the above embodiment, an example has been shown in which, after the pipe connection 2 is formed, liquefied hydrogen is directly flowed into the pipe connection 2 from the first pipe 13. Alternatively, after the pipe connection 2 is formed, air may be simply removed from the pipe connection 2, for example by replacing the air with nitrogen gas or hydrogen gas, and then only the remaining air may be solidified with liquefied hydrogen.

[0050] (2) In the second embodiment, an example has been shown in which liquefied hydrogen is transferred using the main pipe 141 (third pipe) after the solid matter SB has been collected. Alternatively, the main pipe 141 may be treated as a bypass route, and the main pipe 141 may be used only during the operation of disposing of the solid matter SB in the collection section 4, and after the solid matter SB has been disposed of, the liquefied hydrogen may be transferred using the bypass pipe 142. Alternatively, the collection section 4 and the purge pipe 5 may be provided in both the main pipe 141 and the bypass pipe 142, and the two may be used alternately.

[0051] (3) In the second embodiment, an example has been shown in which hydrogen gas at room temperature is used as the purge gas for the collection section 4, and after purging, the collection section 4 is sealed as is to seal the hydrogen gas in the collection section 4. Alternatively, a room temperature purge gas other than hydrogen gas may be used as the purge gas for the collection section 4 to vaporize the solid SB, and then the purge gas may be replaced with hydrogen gas to seal the hydrogen gas in the collection section 4.

[0052] [Summary of this disclosure] The specific embodiments described above include disclosures having the following configurations.

[0053] A method for transferring liquefied hydrogen according to a first aspect of the present disclosure is a method for transferring liquefied hydrogen from a source to a destination using piping, comprising: connecting an end of a first piping extending from the source to an end of a second piping extending from the destination in an air-present environment while being isolated from the interiors of the first piping and the second piping to form a piping connection; introducing the air present inside the piping connection together with liquefied hydrogen supplied from the first piping into a recovery section incorporated in the second piping; and recovering solids generated from the air in the piping connection section in the recovery section.

[0054] According to the first aspect, the air present in the pipe connection part is brought into contact with the liquefied hydrogen supplied from the first pipe to create an environment in which the air is solidified. Then, solid matter generated from the air is collected in the collection part. That is, the air (mainly oxygen and nitrogen) in the pipe connection part is solidified and collected by taking advantage of the phenomenon that liquefied hydrogen solidifies almost all substances. Therefore, the work time for removing air can be significantly shortened compared to the conventional pressure swing method. In addition, since there is no process of replacing the air in the pipe connection part with a purge gas, the amount of nitrogen gas and hydrogen gas used as a purge gas can be significantly reduced. Note that the air remaining in the pipe connection part is solidified instantly by contact with the cryogenic liquefied hydrogen, and since there is no source of ignition, including static electricity, in an environment where liquefied hydrogen accounts for the majority, explosion-proof properties are also guaranteed.

[0055] A method for transferring liquefied hydrogen according to a second aspect is the method of the first aspect, in which a third pipe capable of transferring liquefied hydrogen without passing through the recovery section is set in the second pipe, and after the solid matter is recovered in the recovery section, the liquefied hydrogen is transferred through the third pipe.

[0056] According to the second aspect, the liquefied hydrogen can be transferred to the destination through the third pipe without passing through the recovery section. In other words, the recovery section can be separated from the transfer path of the liquefied hydrogen. This makes it easier to process the solid matter recovered in the recovery section.

[0057] A method for transferring liquefied hydrogen according to a third aspect is the method for transferring liquefied hydrogen according to the second aspect, further comprising the step of supplying a purge gas to the recovery section after the solid matter is recovered in the recovery section, thereby removing the solid matter from the recovery section.

[0058] According to the third aspect, the collected solid matter can be treated by a simple method of supplying a purge gas to the collection section.

[0059] A fourth aspect of the liquefied hydrogen transport method is the same as the third aspect of the liquefied hydrogen transport method, except that a room temperature purge gas is supplied to the recovery section to vaporize the solid matter, thereby removing the solid matter.

[0060] The solid matter is solidified air. According to the fourth aspect, the solid matter can be restored to harmless air simply by supplying a room temperature purge gas to the collection section and exchanging heat with the solid matter.

[0061] A fifth aspect of the present invention relates to a method for transferring liquefied hydrogen, in the method of the fourth aspect, wherein hydrogen gas is supplied to the collection section, and the collection section is sealed in a state filled with hydrogen gas.

[0062] According to the fifth aspect, by filling the collection section with hydrogen gas, the collection section has already been replaced with a hydrogen atmosphere when the next pipe connection section is formed, improving workability.

[0063] A liquefied hydrogen transfer equipment according to a sixth aspect is a liquefied hydrogen transfer equipment that transfers liquefied hydrogen through a first piping extending from a source of liquefied hydrogen, and is equipped with: a transfer piping including a second piping extending from a destination of the liquefied hydrogen and a piping connection part connecting an end of the first piping and an end of the second piping; a cut-off structure part that can seal the end of the first piping and the end of the second piping to cut off the piping connection part from the first piping and the second piping, and can release the seal to cut off the piping connection part from the first piping and the second piping, and a recovery part that is arranged in the second piping downstream of the cut-off structure part and recovers solid matter generated from the air present inside the piping connection part.

[0064] According to the sixth aspect, since the separator structure is provided, the pipe connection section connecting the first pipe and the second pipe can be constructed in an easy working environment exposed to the outside air. Furthermore, since a collection section is disposed downstream of the separator structure, the air in the separator structure can be sent to the collection section while being intentionally brought into contact with the liquefied hydrogen supplied from the first pipe. Then, the solid matter of the air solidified by the contact can be collected in the collection section. Therefore, the work time for removing the air can be shortened, and the amount of purge gas used can be significantly reduced.

[0065] A seventh aspect of the present invention relates to a liquefied hydrogen transfer facility of the sixth aspect, wherein the recovery section includes a filter that traps the solid matter.

[0066] According to the seventh aspect, the solid matter generated from the air can be collected by the filter, and the solid matter can be prevented from moving downstream of the second pipe.

[0067] The liquefied hydrogen transfer equipment according to an eighth aspect is the transfer equipment of the sixth or seventh aspect, wherein the recovery section is incorporated into the second piping at a position adjacent to the isolation structure section.

[0068] According to the eighth aspect, solid matter in the air generated in the edge-cutting structure can be immediately collected in the collection section.

[0069] A liquefied hydrogen transfer facility according to a ninth aspect is the transfer facility of any one of the sixth to eighth aspects, further comprising a third pipe that branches off from the second pipe, bypasses the stripping section, and merges with the second pipe.

[0070] According to the ninth aspect, the liquefied hydrogen can be transferred to the transfer destination through the third pipe without passing through the recovery section. In other words, the recovery section can be separated from the transfer path of the liquefied hydrogen. Therefore, it is easy to process the solid matter recovered in the recovery section.

[0071] A liquefied hydrogen transfer equipment according to a tenth aspect is the transfer equipment of the sixth aspect, wherein the recovery section includes a housing incorporated in the second piping, and further includes a purge piping that supplies a purge gas to the housing and discharges the purge gas from the housing.

[0072] According to the tenth aspect, the collected solid matter can be treated by a simple method of supplying a purge gas from the purge piping to the collection section. By supplying a room temperature purge gas to the collection section using the purge piping, the solid matter can be vaporized and removed. [Explanation of symbols]

[0073] 1. 1A Liquid hydrogen transport equipment 10. Transfer piping 11 Liquefied hydrogen transport source 12 Destination of liquefied hydrogen 13 First Pipe 14 Second piping 141 Main piping (third piping) 142 Bypass piping 2 Pipe connection 3. Edge cutting structure 31, 32, 33, 34, 35 First valve, second valve, third valve, fourth valve, fifth valve 4. Collection Section 41 Filters 5 Purge piping SB Solids

Claims

1. A method for transferring liquefied hydrogen from a transfer source to a transfer destination using piping, comprising the steps of: a pipe connection is formed by connecting an end of a first pipe extending from the transfer source and an end of a second pipe extending from the transfer destination in an air-existing environment while being isolated from the insides of the first pipe and the second pipe; The air present inside the piping connection portion is introduced into a recovery portion incorporated in the second piping together with the liquefied hydrogen supplied from the first piping; A method for transferring liquefied hydrogen, comprising recovering solid matter generated from the air at the piping connection portion in the recovery section.

2. The method for transporting liquefied hydrogen according to claim 1, A third pipe capable of transferring liquefied hydrogen without passing through the recovery section is provided in the second pipe; a third pipe for transferring liquefied hydrogen after the solid matter is recovered in the recovery section.

3. The method for transporting liquefied hydrogen according to claim 2, a purge gas is supplied to the recovery section after the solid matter is recovered in the recovery section, thereby removing the solid matter from the recovery section.

4. The method for transporting liquefied hydrogen according to claim 3, a purge gas at room temperature is supplied to the recovery section to vaporize the solid matter, thereby removing the solid matter.

5. 5. The method for transporting liquefied hydrogen according to claim 4, further comprising supplying hydrogen gas to the recovery section and sealing the recovery section in a state filled with hydrogen gas.

6. A liquefied hydrogen transfer facility that transfers liquefied hydrogen through a first pipe extending from a transfer source of the liquefied hydrogen, A transfer pipe including a second pipe extending from a destination of the liquefied hydrogen and a pipe connection portion connecting an end of the first pipe and an end of the second pipe; an isolation structure that can seal an end of the first pipe and an end of the second pipe to isolate the pipe connection portion from the first pipe and the second pipe, and can release the seal to connect the pipe connection portion to the first pipe and the second pipe; A collection section that is disposed downstream of the edge separation structure section in the second pipe and collects solid matter generated from the air present inside the pipe connection section; A liquefied hydrogen transport facility equipped with:

7. The liquefied hydrogen transport facility according to claim 6, The recovery section is provided with a filter that traps the solid matter.

8. The liquefied hydrogen transport facility according to claim 6, The recovery section is incorporated into the second piping at a position adjacent to the separation structure.

9. The liquefied hydrogen transport facility according to claim 6, The liquefied hydrogen transfer facility further comprises a third pipe branching from the second pipe, bypassing the recovery section, and joining the second pipe.

10. The liquefied hydrogen transport facility according to claim 6, The recovery unit includes a housing incorporated in the second piping, The liquefied hydrogen transfer facility further includes a purge pipe that supplies a purge gas to the housing and discharges the purge gas from the housing.

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