JP6418680B2 - Liquid hydrogen transfer system - Google Patents

Description

  The present invention relates to a liquefied hydrogen transfer system for transferring liquefied hydrogen between a land-side first tank capable of storing liquefied hydrogen and a liquefied hydrogen transport ship-side second tank, and in particular, in the vicinity of its tip including a loading arm. The present invention relates to a liquefied hydrogen transfer system that can be pre-cooled to a level and can prevent generation of solid nitrogen inside an on-off valve.

A liquefied gas transfer system that transfers liquefied gas between a liquefied gas transport ship that transports liquefied gas such as LNG to the sea and a liquefied gas storage tank on land has been put to practical use.
In the LNG receiving apparatus described in Patent Literature 1, an underground tank and a ground tank are provided on the land side, and a loading arm that transfers the LNG from the ship side LNG tank to the land side tank in a state where the LNG transport ship is attached to the pier The LNG transfer system including the LNG is connected, the gas transfer system for transferring the LNG vapor (natural gas) is connected, and when unloading the LNG, the vaporized gas generated from the LNG by the vaporizer is used. The LNG is unloaded from the ship side LNG tank to the land side tank while being supplied to the ship side LNG tank.

FIG. 5 shows a state immediately before connecting a joint portion of the LNG system 100 that transports LNG and a joint portion of the gas system 200 that transports LNG vaporized gas (natural gas).
The land-side LNG system and gas system are provided with loading arms 101 and 201, blind flange cocks 102 and 202, arm lower drain valves 103 and 203, air motor valves 104 and 204, and the like. An operation emergency shutoff valve / high liquid level automatic closing valve 105, a blow-off valve 106, and the like are provided. The ship-side gas system is provided with a remote-operated emergency shut-off valve 205, a blow-off valve 206, and the like.

  When the LNG transport ship arrives, nitrogen gas is purged up to the blind flange cocks 102 and 202 by supplying nitrogen gas from the lower arm drain valves 103 and 203 in the LNG system and gas system on the land side. Thereafter, the joints at the ends of the loading arms 101 and 201 are connected, and nitrogen gas is purged by supplying nitrogen gas from the lower arm drain valves 103 and 203 and discharging the gas from the blow-off valves 106 and 206 on the ship side.

The liquefied hydrogen transfer system for transferring liquefied hydrogen between the first tank on the land side and the second tank on the ship side via the loading arm is similar to the above liquefied gas transfer system, but transfers liquefied hydrogen. Most of the liquefied hydrogen transfer system is composed of a vacuum insulated double pipe and is provided with a bayonet joint that connects the tip of the loading arm to the manifold on the ship side.
At the end of loading or unloading of liquefied hydrogen, an inert gas purge is performed to purge the liquefied hydrogen in the liquefied hydrogen transfer system with an inert gas, and then the bayonet joint is divided. When the bayonet joint is divided, air is mixed into the system, so a blind flange cock is attached, and then a nitrogen gas purge is performed again. The same applies to the hydrogen gas transfer system.

  By the way, the liquefied hydrogen transfer system absorbs the heat in the atmosphere and becomes almost room temperature until the next loading or unloading. When the liquefied hydrogen transfer system is connected between the land side and the ship side and the liquefied hydrogen is allowed to flow in this room temperature state, the liquefied hydrogen rapidly evaporates and a large amount of hydrogen gas is generated. In addition to the reduced transport capacity, it is also disadvantageous in terms of energy. Therefore, prior to loading or unloading of liquefied hydrogen, the liquefied hydrogen transfer system is pre-cooled using liquefied hydrogen.

JP-A-11-210990

  For example, in the land-side liquefied hydrogen transfer system, when the liquefied hydrogen is filled in a region where liquefied hydrogen can be filled and precooled, the on-off valve at the end of the liquefied hydrogen filling region is in contact with liquefied hydrogen and nitrogen gas. Therefore, solid nitrogen is generated inside the on-off valve, and the on-off valve becomes in a fixed state and does not function normally.

  In the case of the LNG transfer system, since the LNG temperature is -162 ° C, which is a relatively high temperature, the amount of LNG evaporated at the start of transfer does not increase. Therefore, it is not necessary to pre-cool the loading arm and its surroundings prior to loading or unloading of LNG. Therefore, when a liquefied hydrogen transfer system similar to the LNG transfer system is employed, a part of the liquefied hydrogen transfer system can be precooled, but the inside of the loading arm cannot be precooled.

  An object of the present invention is to provide a liquefied hydrogen transfer system that can be pre-cooled to the vicinity of its tip including the loading arm of the liquefied hydrogen transfer system, and can prevent generation of solid nitrogen inside the on-off valve. is there.

  The liquefied hydrogen transfer system according to claim 1 is a liquefaction for transferring liquefied hydrogen between a land-side first tank capable of storing liquefied hydrogen and a liquefied hydrogen transport ship-side second tank capable of storing liquefied hydrogen. In the hydrogen transfer system, a liquefied hydrogen transfer system capable of transferring liquefied hydrogen between the first tank and the second tank via a loading arm, most of which is composed of a vacuum insulated double pipe, and the liquefied hydrogen In the land-side transfer system from the first tank of the transfer system to the blind flange on the tip end side of the loading arm, the load arm is disposed in a spaced manner in order from the blind flange side between the outboard arm and the blind flange of the loading arm. A first and second on-off valve; a nitrogen gas filling means capable of filling a first passage portion between the blind flange and the first on-off valve with nitrogen gas; and a second passage between the first and second on-off valves. Part Hydrogen gas filling means capable of filling hydrogen gas, and liquefied hydrogen filling means capable of filling liquefied hydrogen in a third passage portion between the second on-off valve and the first tank for pre-cooling the land-side transfer system, It is characterized by having.

  The liquefied hydrogen transfer system according to a second aspect is the invention according to the first aspect, wherein the hydrogen gas filling means includes a hydrogen gas tank provided in the loading arm, a connection passage connecting the hydrogen gas tank to the second passage portion, An on-off valve provided in the connection passage is provided.

  A liquefied hydrogen transfer system according to a third aspect of the present invention is the liquefied hydrogen transfer system according to the first aspect, wherein a hydrogen gas transfer system for transferring hydrogen gas between the first tank and the second tank, and the second passage portion as a hydrogen gas. An inter-system connection passage connected to the transfer system; and an on-off valve interposed in the inter-system connection passage, wherein the hydrogen gas filling means supplies hydrogen supplied from the first tank via the hydrogen gas transfer system. The second passage portion is filled with gas by the inter-system connection passage.

  According to the invention of claim 1, as described in the section of “Means for Solving the Problems”, the liquefied hydrogen transfer system, the first and second on-off valves, the nitrogen gas filling means, and the hydrogen gas filling And the liquefied hydrogen filling means, the nitrogen gas filling means can fill the first passage part between the blind flange and the first on-off valve with the nitrogen gas, and the hydrogen gas filling means can provide the first passage. , Hydrogen gas can be filled in the second passage portion between the second on-off valves.

  With the first passage portion filled with nitrogen gas and the second passage portion filled with hydrogen gas, liquefied hydrogen is added to the third passage portion between the second on-off valve and the first tank for precooling by the liquefied hydrogen filling means. As long as the temperature of the hydrogen gas in the second passage portion is maintained at a temperature higher than the melting point of nitrogen (−210 ° C.), the nitrogen gas in the first passage portion does not solidify, so the first on-off valve is solid. The function of the on-off valve can be maintained without being fixed by nitrogen. Although the second on-off valve is in contact with the liquefied hydrogen in the third passage portion and the hydrogen gas in the second passage portion, the function of the second on-off valve is maintained because no solid hydrogen is generated inside the second on-off valve. can do.

  At the time of precooling, the liquid hydrogen filling means can fill the third passage portion between the second on-off valve and the first tank with liquid hydrogen, so that most of the loading arm can be precooled.

  According to the invention of claim 2, the hydrogen gas filling means is interposed in the hydrogen gas tank equipped in the loading arm, a connection passage connecting the hydrogen gas tank to the second passage portion, and the connection passage. Since the on-off valve is provided, the second passage portion can be filled with hydrogen gas by the hydrogen gas filling means while discharging the nitrogen gas in the second passage portion through the third passage portion.

  According to the invention of claim 3, a hydrogen gas transfer system for transferring hydrogen gas between the first tank and the second tank, and an inter-system connection for connecting the second passage portion to the hydrogen gas transfer system A passage and an on-off valve interposed in the inter-system connection passage, wherein the hydrogen gas filling means supplies hydrogen gas supplied from the first tank via the hydrogen gas transfer system to the inter-system connection passage. The second passage portion is filled. Therefore, the second passage portion can be filled with hydrogen gas with a simple configuration.

It is a block diagram of the liquefied hydrogen transfer system of Example 1 of this invention. It is a block diagram of the liquefied hydrogen transfer system of Example 2. It is explanatory drawing explaining the positional relationship of the 1st, 2nd on-off valve of FIG. It is explanatory drawing explaining the nitrogen gas purge with respect to the LNG transfer system by the side of the LNG transport ship which concerns on a prior art, and the LNG transfer system by the side of a land.

  Hereinafter, modes for carrying out the present invention will be described based on examples.

  FIG. 1 shows a liquefied hydrogen transfer system 1 according to the first embodiment. The liquefied hydrogen transfer system 1 includes a land-side first tank 2 capable of storing liquefied hydrogen and a liquefied liquid capable of storing liquefied hydrogen. This is a liquefied hydrogen transfer system for transferring liquefied hydrogen to and from the second tank 3 on the hydrogen transport ship side.

  The liquefied hydrogen transfer system 1 includes a liquefied hydrogen transfer system 4, a hydrogen gas transfer system 5, a land-side flexible connection passage 6, a ship-side connection passage 7, a hydrogen gas filling means 8, and a nitrogen gas filling means. 10, a liquefied hydrogen filling means 12, a gas processing device 13, and the like.

  The liquefied hydrogen transfer system 4 is capable of transferring liquefied hydrogen between the first tank 2 and the second tank 3 via the loading arm 14, and most of the liquefied hydrogen transfer system 4 is constituted by a vacuum heat insulating double tube. Is connected to the first tank 2, and the other end is connected to the second tank 3. A loading arm 14 is interposed in the middle of the liquefied hydrogen transfer system 4, and a boundary between the land side and the ship side of the liquefied hydrogen transfer system 4 can be connected by a bayonet joint 17.

  The loading arm 14 includes an inner board arm 14a, an outboard arm 14b, an emergency release device 14c equipped on the outboard arm 14b, first and second on-off valves 15a and 15b, and the hydrogen gas filling means 8. And a blind flange 16 and a cock 16a for closing the open end of the bayonet joint 17 in the separated state. The various on-off valves described in the present embodiment are automatic on-off valves in principle, but manual on-off valves may be adopted for some of the on-off valves.

  In the liquefied hydrogen transfer system 4, the land-side transfer system 4 </ b> A from the first tank 2 to the blind flange 16 includes a check valve 20, an air motor valve 21, a bypass passage 22 that bypasses these, and a bypass passage 22. The mounted on-off valve 23, the drain cock 24 branched from the bypass passage 22, the drain cock 25 branched from the vicinity of the proximal end of the inboard arm 14a of the loading arm 14, the loading arm 14, and the loading arm 14 out Between the board arm 14b and the blind flange 16, there are provided first and second on-off valves 15a and 15b that are sequentially spaced from the blind flange 16 side.

  Further, the nitrogen gas filling means 10 capable of filling the first passage portion 4a between the blind flange 16 and the first on-off valve 15a of the land-side transfer system 4A with the nitrogen gas, the first and second on-off valves 15a, The hydrogen gas filling means 8 capable of filling the second passage portion 4b between 15b with hydrogen gas, and the third passage portion between the second on-off valve 15b and the first tank 2 for precooling the land-side transfer system 4A The liquefied hydrogen filling means 12 capable of filling liquefied hydrogen into 4c is also provided. The liquefied hydrogen filling means 12 includes the first tank 2 and the land-side transfer system 4A.

  The hydrogen gas filling means 8 is provided in a passage portion extending from the tip of the outboard arm 14 b of the loading arm 14. The hydrogen gas filling means 8 includes a hydrogen gas tank 8a that stores pressurized hydrogen gas, a filling passage 8b that connects the hydrogen gas tank 8a to the second passage portion 4b, and an open / close interposed in the filling passage 8b. A valve 8c and a pressure gauge and a temperature detector capable of detecting the pressure and temperature of the hydrogen gas in the filling passage 8b are provided.

  The ship side transfer system 4B of the liquefied hydrogen transfer system 4 is provided with a remote operation emergency shut-off / high liquid level automatic closing valve 26, a bypass passage 27 for bypassing the automatic closing valve 26, and a bypass passage 27. The open / close valve 28, a blind flange 29 for closing the open end of the separated bayonet joint 17, and an open / close valve 30 interposed in the vicinity of the blind flange 29 are provided.

  The hydrogen gas transfer system 5 is capable of transferring hydrogen gas between the first tank 2 and the second tank 3 via the loading arm 34, most of which is composed of, for example, a single tube made of stainless steel, One end is connected to the first tank 2 and the other end is connected to the second tank 3. The boundary between the land side and the ship side of the hydrogen gas transfer system 5 can be connected by a flange joint 35. A loading arm 34 is interposed in the middle of the hydrogen gas transfer system 5. The loading arm 34 includes an inboard arm 34a, an outboard arm 34b, and an emergency release device 34c.

  The land-side transfer system 5A of the hydrogen gas transfer system 5 includes a check valve 36, an air motor valve 37, a bypass passage 38 for bypassing these, a switching valve 39 interposed in the bypass passage 38, a bypass A drain cock 40 branched from the passage 38, a drain cock 41 branched from the vicinity of the proximal end portion of the inboard arm 34a of the loading arm 34, the loading arm 34, and a blind flange for closing the open end of the flange joint 35 in a separated state 42 and an on-off valve 43 provided in the vicinity of the blind flange 42 is provided.

  The ship side transfer system 5B of the hydrogen gas transfer system 5 includes a remote-operated emergency shut-off valve 44, a blind flange 45 that closes the open end of the separated flange joint 35, and an open / close provided near the blind flange 45. A valve 46 is provided.

  The flexible connection passage 6 is an inter-system connection passage for connecting the liquefied hydrogen transfer system 4 and the hydrogen gas transfer system 5 on the land side, and is made of, for example, a flexible tube made of stainless steel. One end of the flexible connection passage 6 is connected to a portion of the liquefied hydrogen transfer system 4 between the emergency release device 14 c and the second on-off valve 15 b, and the other end is an emergency release device 34 c of the hydrogen gas transfer system 5. And a portion between the on-off valve 43. The flexible connection passage 6 is provided with an on-off valve 6a.

  The connection passage 7 connects the liquefied hydrogen transfer system 4 and the hydrogen gas transfer system 5 on the liquefied hydrogen transport ship side, and an open / close valve 7 a is interposed in the connection passage 7. One end of the connection passage 7 is connected to a portion of the liquefied hydrogen transfer system 4 between the on-off valve 30 and the automatic closing valve 26, and the other end of the on-off valve 46 and the emergency shut-off valve 44 in the hydrogen gas transfer system 5. Connected to the part between.

Next, the operation and effect of the liquefied hydrogen transfer system 1 will be described.
Immediately after the end of the previous loading or unloading of liquefied hydrogen, a nitrogen gas purge is performed to replace the hydrogen gas in the land-side transfer systems 4A and 5A with nitrogen gas, and most of the land-side transfer systems 4A and 5A have nitrogen. Gas is filled, and the first and second on-off valves 15a. 15b is a valve closing state, and the inside of the 1st channel | path part 4a is also filled with nitrogen gas. The same applies to the ship side transfer systems 4B and 5B, and the inside of the ship side transfer systems 4B and 5B is also filled with nitrogen gas.

  Next, a technique for pre-cooling the land-side transfer system 4A of the liquefied hydrogen transfer system 4 prior to the next loading or unloading of liquefied hydrogen will be described. This pre-cooling is performed in order to minimize the amount of evaporation of liquefied hydrogen at the next loading or unloading of liquefied hydrogen.

  First, the nitrogen gas in the second and third passage portions 4b and 4c is replaced with hydrogen gas while the first passage portion 4a is filled and held with nitrogen gas. In this case, the hydrogen gas supplied from the first tank 2 to the third passage portion 4c is discharged to the gas processing device 13 through the flexible connection passage 6, the loading arm 34, and the gas passage 13a.

  In parallel with this, the second on-off valve 15b is opened, hydrogen gas is supplied from the hydrogen gas filling means 8 to the second passage portion 4b, and the nitrogen gas in the second passage portion 4b is supplied to the third passage portion 4c. To the flexible connection passage 6 and to the gas processing device 13 through the loading arm 34 and the gas passage 13a. After filling hydrogen gas from the hydrogen gas filling means 8 for a predetermined time, the second on-off valve 15b is closed. Thus, the nitrogen gas in the second and third passage portions 4b and 4c can be replaced with hydrogen gas.

Next, in order to pre-cool the land-side transfer system 4A, the third passage portion 4c is filled with liquefied hydrogen.
In this case, liquefied hydrogen is metered from the first tank 2 and supplied to the third passage portion 4c. After supplying liquefied hydrogen in an amount substantially equal to the volume of the third passage portion 4c, the supply is stopped and the on-off valve 6a is closed. To do. In this way, the hydrogen gas in the third passage portion 4c is discharged to the gas processing device 13 through the flexible connection passage 6, the loading arm 34, and the gas passage 13a, and is largely discharged in the third passage portion 4c. It can be precooled by filling with liquefied hydrogen.

  During this pre-cooling, one side of the second on-off valve 15b comes into contact with liquefied hydrogen in the third passage portion 4c, and the other side comes into contact with hydrogen gas in the second passage portion 4b. Therefore, the function of the second on-off valve 15b can be maintained.

  One side of the first on-off valve 15a is in contact with the hydrogen gas in the second passage portion 4b, and the other side is in contact with the nitrogen gas in the first passage portion 4a. Since the temperature of the hydrogen gas in the second passage portion 4b is sufficiently higher than the freezing point of nitrogen gas (−210 ° C.), solid nitrogen is not generated on the other side of the first on-off valve 15a, and the first on-off The function of the valve 15a can be maintained.

  Next, immediately before loading or unloading of liquefied hydrogen (before connection of the bayonet joint 17), the land-side transfer system 4A is filled with hydrogen gas. In this case, hydrogen gas is supplied from the first tank 2 to the flexible connection passage 6 via the land-side transfer system 5A, and the liquefied hydrogen in the third passage portion 4c of the land-side transfer system 4A is returned to the first tank 2. . In this state, the second and third passage portions 4b and 4c of the land-side transfer system 4A and the inside of the land-side transfer system 5A are filled with hydrogen gas.

  Next, when the liquefied hydrogen transport ship arrives at the pier, the bayonet joint 17 and the flange joint 35 are connected via movement by the loading arms 14, 34, and then the liquefied hydrogen transport system 4 and the hydrogen gas transport system 5 are connected. The nitrogen gas inside is replaced with hydrogen gas. At this time, the nitrogen gas in the liquefied hydrogen transfer system 4 is discharged together with the hydrogen gas to the gas processing device 13, and the nitrogen gas in the hydrogen gas transfer system 5 is discharged together with the hydrogen gas to the gas processing device 13. Thereafter, loading or unloading of liquefied hydrogen is performed.

  According to the liquefied hydrogen transfer system 1, the hydrogen gas is filled between the liquefied hydrogen in the third passage 4c and the nitrogen gas in the first passage portion 4a by filling the second passage portion 4b with hydrogen gas. A buffer region is provided to prevent the generation of solid nitrogen inside the first and second on-off valves 15a and 15b, thereby maintaining the functions of the first and second on-off valves 15a and 15b.

  In addition, since the flexible connection passage 6 and the on-off valve 6a are provided, liquefied hydrogen can be filled into the loading arm 14 during pre-cooling, and the amount of liquefied hydrogen evaporated during loading or unloading of liquefied hydrogen is remarkably increased. Can be reduced.

  Most of the liquefied hydrogen transfer system 1A of the second embodiment shown in FIG. 2 is the same as the liquefied hydrogen transfer system 1 of the first embodiment. Different components will be described.

  The hydrogen gas filling means 8 is changed, the hydrogen gas tank 8a is omitted, and in the land-side transfer system 4A, the filling passage 8b is connected to the land-side transfer system 5A side rather than the on-off valve 6a in the flexible connection passage 6. Has been. Therefore, the hydrogen gas supplied from the first tank 2 to the third passage portion 4c of the land-side transfer system 4A can be filled into the second passage portion 4b via the flexible connection passage 6 and the filling passage 8b. The second passage portion 4b can be filled with hydrogen gas by holding the on-off valve 8c in the closed state later. In addition, since the operation and effect of the liquefied hydrogen transfer system 1A are the same as the operation and effect of the liquefied hydrogen transfer system 1, description thereof will be omitted.

Next, a desirable positional relationship between the blind flange 16 and the first and second on-off valves 15a and 15b in the precooled state will be described with reference to FIG.
In this precooled state, the first passage portion 4a is filled with nitrogen gas (GN2), the second passage portion 4b is filled with hydrogen gas (GH2), and the third passage portion 4c is filled with liquefied hydrogen (LH2). Has been. The temperature of the blind flange 16 is normal temperature (300K), and since the second on-off valve 15b is in contact with liquefied hydrogen, the temperature is 20K, and the temperature of the first on-off valve 15a is T.

Assuming that the heat transfer cross section is constant, the following equation is obtained based on the thermal equilibrium calculation.
(T-20) / D1 = (300-T) / D2
When D2 = 1.0 m and T = 100K, D1 = 0.4 m is obtained from the above equation.
That is, by appropriately setting the length of the first passage portion 4a and setting the length of the second passage portion 4b to about 40% or more of the length of the first passage portion 4a, the first on-off valve 15a. Can be prevented from becoming too cold.

Next, an example in which the above embodiment is partially changed will be described.
1) The bayonet joint 17 is merely an example, and other low-temperature fluid joints may be employed.
2) The arrangement of the various on-off valves provided in the liquefied hydrogen transfer systems 1 and 1A is merely an example, and the on-off valves may be provided in an arrangement different from this arrangement.
3) Besides, it goes without saying that those skilled in the art can implement the present invention in various modifications.

  The present invention relates to a liquefied hydrogen transfer system for transferring liquefied hydrogen between a first tank on the land side capable of storing liquefied hydrogen and a second tank on the liquefied hydrogen transport ship side, particularly including a loading arm. Provided is a liquefied hydrogen transfer system that can be pre-cooled to the vicinity of the tip and prevent generation of solid nitrogen inside an on-off valve.

1, 1A Liquefied hydrogen transfer system 2 First tank 3 Second tank 4 Liquefied hydrogen transfer system 4A Land side transfer system 4a First passage 4b Second passage 4c Third passage 5 Hydrogen gas transfer system 6 Flexible connection passage (between systems Connection passage)
6a On-off valve 8 Hydrogen gas filling means 8a Hydrogen gas tank 8b Filling passage 8c On-off valve 12 Liquefied hydrogen filling means 14 Loading arm 14b Outboard arms 15a, 15b First and second on-off valves

Claims (3)

In a liquefied hydrogen transfer system for transferring liquefied hydrogen between a land-side first tank capable of storing liquefied hydrogen and a liquefied hydrogen transport ship-side second tank capable of storing liquefied hydrogen,
A liquefied hydrogen transfer system capable of transferring liquefied hydrogen between the first tank and the second tank via a loading arm, most of which comprises a vacuum insulated double pipe;
In the land-side transfer system from the first tank of the liquefied hydrogen transfer system to the blind flange on the tip end side of the loading arm, the load arm is spaced apart from the blind flange side in order from the blind flange side. First and second on-off valves provided;
Nitrogen gas filling means capable of filling the first passage portion between the blind flange and the first on-off valve with nitrogen gas;
Hydrogen gas filling means capable of filling the second passage portion between the first and second on-off valves with hydrogen gas;
A liquefied hydrogen transfer system comprising liquefied hydrogen filling means capable of filling liquefied hydrogen in a third passage between the second on-off valve and the first tank for pre-cooling the land-side transfer system. .   The hydrogen gas filling means includes a hydrogen gas tank provided in the loading arm, a connection passage for connecting the hydrogen gas tank to the second passage portion, and an on-off valve interposed in the connection passage. The liquefied hydrogen transfer system according to claim 1. A hydrogen gas transfer system for transferring hydrogen gas between the first tank and the second tank, an inter-system connection passage connecting the second passage portion to the hydrogen gas transfer system, and an inter-system connection passage; With an installed on-off valve,
2. The hydrogen gas filling means fills the second passage portion with hydrogen gas supplied from the first tank via the hydrogen gas transfer system through the inter-system connection passage. Liquid hydrogen transfer system.