Tank equipment and liquid hydrogen delivery method

Abstract

To perform an economical operation of tank equipment for storing liquid hydrogen by suppressing the power consumption of a boil-off gas compressor.SOLUTION: A discharge method of liquid hydrogen of the tank equipment includes steps for: compressing a boil-off gas of liquid hydrogen which flows out of a tank to prescribed post-compression pressure exceeding the critical pressure of hydrogen by using a compressor; cooling the boil-off gas which has been brought into an ultra-critical fluid state by compression to a temperature lower than a critical temperature of hydrogen; pressurizing the boil-off gas which has been brought into a compressive liquid state by cooling to prescribed post-pressurization pressure which exceeds the critical pressure of hydrogen, and is higher than the post-compression pressure by using a pump; and merging the boil-off gas which has been brought into the ultra-critical liquid state once again by pressurization with the liquid hydrogen which has been discharged from the tank, or merging an evaporated product obtained by evaporating the boil-off gas which has been brought into the ultra-critical liquid state once again by pressurization with an evaporated product obtained by evaporating the liquid hydrogen which has been discharged from the tank.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a tank facility for storing liquid hydrogen and a method for dispensing liquid hydrogen from the tank facility. [Background technology]

[0002] Low-temperature liquefied gas such as LNG (Liquefied Natural Gas) is transported to a receiving terminal by a liquefied gas transport means such as a ship, and temporarily stored in a tank facility at the receiving terminal. The stored liquefied gas is vaporized in the tank facility and sent outside. Patent Document 1 shows an example of this type of tank facility.

[0003] The tank equipment disclosed in Patent Document 1 includes a tank for storing low-temperature liquefied gas, an in-tank pump for discharging the liquefied gas from the tank, a boil-off gas compressor for compressing boil-off gas that is naturally generated in the tank due to heat input, a recondenser (direct contact heat exchanger) for re-liquefying the boil-off gas by mixing the compressed boil-off gas with a portion of the liquefied gas discharged from the in-tank pump, and a vaporizer for vaporizing the liquefied boil-off gas and liquefied gas. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2014-142021 Summary of the Invention [Problem to be solved by the invention]

[0005] As with low-temperature liquefied gases such as LNG, a method is being considered for liquefied hydrogen, in which it is temporarily stored in tank facilities, vaporized in the tank facilities, and then sent outside. However, because liquefied hydrogen has a lower latent heat of vaporization than LNG, it is expected that the amount of boil-off gas naturally generated in the tank due to heat input from the outside will be greater than that of LNG. In LNG gas tank facilities, the boil-off gas compressor is one of the devices that consumes a lot of power, and as mentioned above, the amount of boil-off gas generated with liquefied hydrogen is greater than that of LNG, so it is expected that the power consumption of the boil-off gas compressor will be even greater.

[0006] The present disclosure has been made in consideration of the above circumstances, and its purpose is to enable economical operation of a tank facility for storing liquid hydrogen and a method for discharging liquid hydrogen from the tank facility by reducing the power consumption of a boil-off gas compressor. [Means for solving the problem]

[0007] In order to solve the above problems, a liquid hydrogen delivery method according to one aspect of the present disclosure includes: Compressing the boil-off gas of liquid hydrogen flowing out of the tank to a predetermined post-compression pressure that exceeds the critical pressure of hydrogen using a compressor; cooling the boil-off gas that has been compressed into a supercritical fluid state to a temperature lower than the critical temperature of hydrogen; Pressurizing the boil-off gas that has been cooled to a compressible liquid state by a pump to a predetermined post-compression pressure that exceeds the critical pressure of hydrogen and is higher than the post-compression pressure; The boil-off gas, which has been pressurized to a supercritical fluid state again, is merged with the liquid hydrogen discharged from the tank, or the boil-off gas, which has been pressurized to a supercritical fluid state again, is merged with the vaporized liquid hydrogen discharged from the tank.

[0008] Further, a tank facility according to one aspect of the present disclosure includes: a tank having a liquid inlet, a liquid outlet, and a gas outlet, in which liquid hydrogen is stored; a receiving line connected to the liquid inlet of the tank through which the liquid hydrogen to be received into the tank flows; a delivery line through which the liquid hydrogen delivered from the tank flows, the delivery line including, in order from upstream, a first pump connected to the liquid outlet of the tank for pumping the liquid hydrogen downstream and a first vaporizer for vaporizing the liquid hydrogen; a BOG line connected to the gas outlet of the tank and into which boil-off gas generated by vaporization of the liquid hydrogen in the tank flows, The BOG line has, in order from the upstream side, a BOG compressor that compresses the boil-off gas to a predetermined post-compression pressure that exceeds the critical pressure of hydrogen, a cooler that cools the boil-off gas that has been compressed into a supercritical fluid state to a temperature lower than the critical temperature of hydrogen, a second pump that pressurizes the boil-off gas that has been cooled into a compressible liquid state to a predetermined post-compression pressure that exceeds the critical pressure of hydrogen and is higher than the post-compression pressure, and a second vaporizer that vaporizes the boil-off gas that has been pressurized back into a supercritical fluid state, and is connected to the discharge line downstream of the second pump. [Effects of the Invention]

[0009] According to one aspect of the present disclosure described above, in a tank facility for storing liquid hydrogen and a method for discharging liquid hydrogen from the tank facility, it is possible to reduce the power consumption of the boil-off gas compressor and achieve economical operation of the tank facility. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing a schematic configuration of a tank facility according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a phase diagram of hydrogen. [Figure 3] FIG. 3 is a schematic diagram showing a schematic configuration of a tank facility according to the first modification. DETAILED DESCRIPTION OF THE INVENTION

[0011] Next, an embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic diagram showing a general configuration of a tank facility 1 according to an embodiment of the present disclosure. In this figure, the flow of boil-off gas 300 in the tank facility 1 is indicated by thick arrows.

[0012] As shown in FIG. 1 , a tank facility 1 according to the present disclosure is installed, for example, at a liquefied gas receiving terminal 11 in a coastal area. Liquid hydrogen 100 is stored in the tank facility 1 according to this embodiment. An unloading arm 5, a return gas arm 16, and the tank facility 1 are installed in the liquefied gas receiving terminal 11. The unloading arm 5 and the return gas arm 16 are arranged at a quay where a liquefied gas transport means 10, such as a liquefied gas carrier, docks. The tank facility 1 is a facility that receives and stores the liquid hydrogen 100 transported by the liquefied gas transport means 10, vaporizes the stored liquid hydrogen 100, and sends it out. The tank facility 1 is not limited to being installed in a coastal area, and may be installed on land or sea depending on the liquefied gas transport means 10.

[0013] The tank facility 1 includes a tank 2, a receiving line 3, a delivery line 7, a return gas line 15, and a BOG line 12.

[0014] Tank 2 is a container that stores liquid hydrogen 100 in a low-temperature liquid state. Because the liquid hydrogen 100 in tank 2 is stored at approximately its boiling point, the liquid hydrogen 100 naturally vaporizes in tank 2, generating boil-off gas 300, which accumulates in the upper and top portions of tank 2. Tank 2 has a liquid inlet 24, a liquid outlet 25, and a gas outlet 26. Gas outlet 26 opens at the top or top of tank 2.

[0015] The receiving line 3 connects the unloading arm 5 and the tank 2. The upstream end of the receiving line 3 is connected to the unloading arm 5, and the downstream end is connected to the liquid inlet 24 of the tank 2. A receiving valve 4 that opens and closes the flow path of the receiving line 3 is provided in the downstream portion of the receiving line 3. When receiving liquid hydrogen 100, the receiving valve 4 is opened, and the low-temperature liquid hydrogen 100 transported by the liquefied gas transportation means 10 is supplied to the receiving line 3 through the unloading arm 5, flows into the tank 2 through the receiving line 3, and is stored in the tank 2.

[0016] The discharge line 7 connects the liquid outlet 25 of the tank 2 to the gas delivery line 9. The gas delivery line 9 is a pipe that delivers hydrogen gas 200 to the outside of the tank facility 1. The discharge line 7 is provided with a discharge pump 6. However, the discharge pump 6 may also be provided in the tank 2. The discharge pump 6 increases the pressure of the liquid hydrogen 100 to a level required for gas delivery and pumps it downstream.

[0017] A BOG cooler 62 is disposed downstream of the discharge pump 6 on the discharge line 7. The liquid hydrogen 100 in the discharge line 7 is used as a refrigerant in the BOG cooler 62.

[0018] A vaporizer 8 is disposed downstream of the BOG cooler 62 on the discharge line 7. The vaporizer 8 forcibly vaporizes the liquid hydrogen 100 into hydrogen gas 200 by, for example, exchanging heat between water supplied from the outside and the liquid hydrogen 100 supplied through the discharge line 7.

[0019] The upstream end of the BOG line 12 is connected to the gas outlet 26 of the tank 2. Boil-off gas 300 that has accumulated in the upper part of the tank 2 flows out into the BOG line 12. The downstream end of the BOG line 12 is connected to a connection part 71 that is arranged in the discharge line 7. The connection part 71 is arranged in the discharge line 7 downstream of the BOG cooler 62 and upstream of the vaporizer 8.

[0020] A BOG compressor 14 is provided in the BOG line 12. The BOG compressor 14 may be, for example, a reciprocating type compressor including a cylinder that draws in low-temperature boil-off gas 300 and a piston that compresses the drawn boil-off gas 300. The BOG compressor 14 adiabatically compresses the boil-off gas 300 flowing through the BOG line 12.

[0021] A BOG cooler 62 is disposed in the BOG line 12 downstream of the BOG compressor 14. The BOG cooler 62 is a surface heat exchanger in which the liquid hydrogen 100 passing through the discharge line 7 and the boil-off gas 300 passing through the BOG line 12 exchange heat via a heat transfer surface without direct contact. Examples of such surface heat exchangers include a shell-and-tube heat exchanger, a fin-and-tube heat exchanger, a fin-and-plate heat exchanger, and a regenerative heat exchanger.

[0022] A pump 61 is disposed downstream of the BOG cooler 62 in the BOG line 12. The pump 61 pressurizes the fluid flowing through the BOG line 12. The pump 61 may be a pump configured to pressurize and pump out a liquid.

[0023] The return gas line 15 connects the tank 2 and the return gas arm 16. In the tank facility 1 according to this embodiment, the return gas line 15 is connected to the gas outlet 26 of the tank 2 via the upstream portion of the BOG line 12. The downstream end of the return gas line 15 is connected to the return gas arm 16. A return gas blower 21 is provided in the middle of the return gas line 15. The return gas blower 21 is operated, for example, during pre-cooling of the receiving line 3 (described below) or during receiving of liquefied hydrogen 100. During receiving of liquefied hydrogen 100, operation of the return gas blower 21 returns a portion of the boil-off gas 300 in the tank 2 to the loading tank of the liquefied gas transportation means 10 through the return gas line 15 and the return gas arm 16, thereby compensating for the drop in loading tank pressure associated with loading. Note that if the pressure of the boil-off gas 300 is sufficiently high, the return gas blower 21 may be omitted.

[0024] [Liquid Hydrogen 100 Dispensing Method] Here, a method for dispensing liquid hydrogen 100 in the tank facility 1 having the above configuration will be described with reference to Figures 1 and 2. Figure 2 is a phase diagram of hydrogen.

[0025] In the tank facility 1, the liquid hydrogen 100 stored in the tank 2 flows out into the discharge line 7 by operation of the discharge pump 6, and is pressurized by the discharge pump 6 to the pressure required for gas transmission. The discharge pump 6 pressurizes the liquid hydrogen 100 from pressure P21 to a predetermined post-compression pressure P22, and the liquid hydrogen 100 becomes a compressible liquid. The liquid hydrogen 100 in the compressible liquid state passes through a BOG cooler 62 and is sent to a vaporizer 8. The liquid hydrogen 100 is vaporized in the vaporizer 8 to become hydrogen gas 200, which is then pumped to a gas transmission line 9.

[0026] Furthermore, in the tank facility 1, heat input to the tank 2 causes the liquid hydrogen 100 in the tank 2 to spontaneously vaporize, generating boil-off gas 300. When the BOG compressor 14 is operated, the boil-off gas 300 flows from the tank 2 to the BOG line 12 and is compressed by the BOG compressor 14.

[0027] The BOG compressor 14 adiabatically compresses the boil-off gas 300 from pressure P11 to a post-compression pressure P12. The post-compression pressure P12 exceeds 1.185 MPaG, which is the critical pressure Pcr of hydrogen. Therefore, the boil-off gas 300 at the post-compression pressure P12 is in a supercritical fluid state. It is desirable that the post-compression pressure P12 be slightly higher than the critical pressure Pcr of hydrogen so that the boil-off gas 300 flows through the BOG line 12 from the BOG compressor 14 to the BOG cooler 62 while maintaining the supercritical fluid state. On the other hand, if the post-compression pressure P12 is excessively high, the power consumption of the BOG compressor 14 increases. From this perspective, the post-compression pressure P12 is higher than 1.185 MPaG and lower than 2.5 MPaG, more preferably higher than 1.185 MPaG and lower than 1.5 MPaG.

[0028] The boil-off gas 300 in the supercritical fluid state is cooled by heat exchange with the liquid hydrogen 100 in the BOG cooler 62. The BOG cooler 62 cools the boil-off gas 300 from temperature T12 to temperature T13. The temperature T13 is lower than −240.21°C, which is the critical temperature Tcr of hydrogen. Since the temperature of the liquid hydrogen 100 is −252.5°C, the temperature T13 is higher than −252.5°C and lower than −240.21°C. The boil-off gas 300 in the supercritical fluid state is cooled to temperature T13 and changes to a compressible liquid state.

[0029] The boil-off gas 300 in a compressible liquid state is pressurized by a pump 61. The pump 61 increases the pressure of the boil-off gas 300 from a pressure P13 to a post-compression pressure P14. The pressure P13 is lower than the post-compression pressure P12 by a pressure loss, but is substantially the same as the post-compression pressure P12. The post-compression pressure P14 is substantially the same as the pressure P22 of the liquid hydrogen 100 after being pressurized by the discharge pump 6. The post-compression pressure P14 is higher than the critical pressure Pcr of hydrogen and the post-compression pressure P12. The post-compression pressure P14 is set to a pressure higher than the delivery gas pressure, taking into account that the pressure of the boil-off gas 300 is reduced in the vaporizer 8. The post-compression pressure P14 is a value according to the requirements of the facility receiving the delivery gas, and is, for example, 3 MPaG or more and 5 MPaG or less. The boil-off gas 300 in a compressible liquid state is pressurized to the post-compression pressure P14 and changes back to a supercritical fluid state.

[0030] The boil-off gas 300 in a supercritical fluid state joins with the liquid hydrogen 100 in a compressible liquid state flowing through the discharge line 7 and flows into the vaporizer 8. In the vaporizer 8, the boil-off gas 300 is vaporized in the same manner as the liquid hydrogen 100 to become hydrogen gas 200, which is then pumped to the gas delivery line 9.

[0031] [Variation 1] Here, a first modification of the above embodiment will be described. Fig. 3 is a schematic diagram showing the general configuration of a tank facility 1 according to the first modification. In this figure, the flow of boil-off gas 300 in the tank facility 1 is indicated by thick arrows. In the description of this modification, the same or similar members as those in the above embodiment are denoted by the same reference numerals in the drawings, and their description will be omitted.

[0032] 3, in the tank facility 1 according to the first modification, the downstream end of the BOG line 12 is connected to the discharge line 7 downstream of the vaporizer 8. Then, downstream of the pump 61 on the BOG line 12, a vaporizer 80 independent of the vaporizer 8 on the discharge line 7 is provided. In this manner, in the tank facility 1 according to the first modification, the boil-off gas 300 flowing into the BOG line 12 is compressed by the BOG compressor 14 to become a supercritical fluid, cooled by the BOG cooler 62 to become a compressible liquid, pressurized by the pump 61 to become a supercritical fluid, vaporized by the vaporizer 80, and then merged with the hydrogen gas 200 flowing through the discharge line 7.

[0033] In the configuration according to the first modification, the pressure P14 after pressurization of the boil-off gas 300 pressurized by the pump 61 does not have to be the same as the pressure P22 of the liquid hydrogen 100 in the discharge line 7.

[0034] [Summary] As described above, the method for dispensing liquid hydrogen 100 according to the present disclosure includes the following steps: Compressing the boil-off gas 300 of the liquid hydrogen 100 flowing out of the tank 2 by the compressor 14 to a post-compression pressure P12 exceeding the critical pressure Pcr of hydrogen; Cooling the boil-off gas 300 that has been compressed into a supercritical fluid state to a temperature T13 that is lower than the critical temperature Tcr of hydrogen; The boil-off gas 300 that has been cooled to a compressible liquid state is pressurized by a pump 61 to a post-compression pressure P14 that exceeds the critical pressure Pcr of hydrogen and is higher than the post-compression pressure P12. This includes combining the boil-off gas 300, which has been pressurized to a supercritical fluid state again, with the liquid hydrogen 100 discharged from the tank 2, or combining the vaporized boil-off gas 300, which has been pressurized to a supercritical fluid state again, with the vaporized liquid hydrogen 100 discharged from the tank 2.

[0035] Similarly, the tank facility 1 according to the present disclosure includes: a tank 2 having a liquid inlet 24, a liquid outlet 25, and a gas outlet 26, in which liquid hydrogen 100 is stored; a receiving line 3 connected to the liquid inlet 24 of the tank 2 and through which the liquid hydrogen 100 to be received into the tank 2 flows; a first pump 6 connected to a liquid outlet 25 of the tank 2 for pumping liquid hydrogen 100 downstream, and a first vaporizer 8 for vaporizing the liquid hydrogen 100, in this order from the upstream side; and a delivery line 7 through which the liquid hydrogen 100 delivered from the tank 2 flows; The BOG line 12 is connected to the gas outlet 26 of the tank 2 and receives boil-off gas 300 produced by vaporization of the liquid hydrogen 100 in the tank 2. The BOG line 12 has, in order from the upstream side, a BOG compressor 14 that compresses the boil-off gas 300 to a post-compression pressure P12 that exceeds the critical pressure Pcr of hydrogen, a BOG cooler 62 that cools the boil-off gas 300 that has become a supercritical fluid state by compression to a temperature lower than the critical temperature Tcr of hydrogen, a second pump 61 that pressurizes the boil-off gas 300 that has become a compressible liquid state by cooling to a post-compression pressure P14 that exceeds the critical pressure Pcr of hydrogen and is higher than the post-compression pressure P12, and second vaporizers 8 and 80 that vaporize the boil-off gas 300 that has become a supercritical fluid state again by pressurization, and is connected to the discharge line 7 downstream of the second pump 61.

[0036] In the above-described method for dispensing liquid hydrogen 100 and tank facility 1, the post-compression pressure P12 may be higher than 1.185 MPaG and lower than 2.5 MPaG. Alternatively, the post-compression pressure P12 may be higher than 1.185 MPaG and lower than 1.5 MPaG.

[0037] According to the above-described method for discharging liquid hydrogen 100 and tank facility 1, the boil-off gas 300 that has flowed into the BOG line 12 is compressed to a supercritical fluid by the BOG compressor 14 and then cooled by the BOG cooler 62, thereby becoming a compressible liquid that can be pressurized by the pump 61. Since the boil-off gas 300 whose state has changed in this way can be pressurized by the pump 61, it is not necessary to increase the pressure to the post-pressurization pressure P14 only by the BOG compressor 14, but it is sufficient to increase the pressure to the post-pressurization pressure P14 in stages by the BOG compressor 14 and the pump 61. To explain this with specific figures, in the case where boil-off gas 300 is compressed to the delivery gas pressure of 3.5 MPaG at a flow rate of 1.2 t / h and has a flow rate of 0.010 MPaG, the power consumption of the BOG compressor 14 when compressed to the delivery gas pressure using only the BOG compressor 14 is 900 kW, whereas when the BOG compressor 14 compresses the gas to 1.4 MPaG, then the pump 61 pressurizes the gas to 4.1 MPaG, and then the vaporizers 8, 80 reduce the pressure to the delivery gas pressure, the power consumption of the BOG compressor 14 and the pump 61 is 490 kW, meaning that the latter case consumes approximately 50% less power than the former case.

[0038] As described above, the liquid hydrogen 100 delivery method and tank facility 1 configured as described above can reduce the power consumption of the BOG compressor 14 compared to when the boil-off gas 300 is pressurized to the delivery gas pressure using only the BOG compressor 14, thereby enabling economical operation of the tank facility 1. Furthermore, a BOG compressor 14 with a low compression ratio can be used.

[0039] Furthermore, according to the above-described method for discharging liquid hydrogen 100 and tank facility 1, the boil-off gas 300 flowing into the BOG cooler 62 is in a supercritical fluid state. Since the supercritical fluid does not undergo a phase change during the cooling process by the BOG cooler 62, the BOG cooler 62 can be operated stably.

[0040] The pressure at which LNG is sent from the tank facility to the power plant is generally 4 to 5 MPaG. The critical pressure of methane, the main component of LNG, is 4.60 MPaG. There is almost no pressure difference between the critical pressure of LNG and the sending pressure that allows the pump 61 to apply pressure. On the other hand, the critical pressure of hydrogen is 1.185 MPaG. There is a sufficient pressure difference between the critical pressure of the boil-off gas of liquid hydrogen and the sending pressure that allows the pump 61 to apply pressure. Therefore, the liquid hydrogen 100 delivery method and tank facility 1 of the present disclosure are difficult to apply to LNG and are particularly suitable for liquid hydrogen 100.

[0041] In the above tank equipment 1, the post-pressurization pressure P14 is substantially the same as the pressure P22 of the liquid hydrogen 100 flowing into the first vaporizer 8, the BOG line 12 is connected to the discharge line 7 at the inlet of the first vaporizer 8, and the second vaporizer 80 may be shared with the first vaporizer 8.

[0042] According to the tank facility 1 having the above configuration, the number of vaporizers 8, 80 can be reduced.

[0043] In the above-described method for delivering liquid hydrogen 100, cooling the boil-off gas 300 in a supercritical fluid state may include heat exchanging between the boil-off gas 300 in a supercritical fluid state and the liquid hydrogen 100 in a surface heat exchanger.

[0044] Similarly, in the tank equipment 1 according to the present disclosure, the BOG cooler 62 may be a surface heat exchanger that exchanges heat between the liquid hydrogen 100 flowing through the discharge line 7 and the boil-off gas 300 flowing through the BOG line 12.

[0045] According to the above-described method for discharging liquid hydrogen 100 and tank facility 1, it is possible to perform heat exchange between the boil-off gas 300 and the liquid hydrogen 100, which are fluids having different pressures.

[0046] The foregoing discussion of the present disclosure has been presented for purposes of illustration and description and is not intended to limit the present disclosure to the form disclosed herein. For example, in the foregoing Detailed Description, various features of the present disclosure are grouped together in a single embodiment for the purpose of streamlining the disclosure. However, multiple features included in the present disclosure can be combined into alternative embodiments, configurations, or aspects other than those discussed above. [Explanation of symbols]

[0047] 1: Tank facilities 2: Tank 3: Receiving line 6: Pump 7: Payment line 8,80: Vaporizer 12:BOG line 14: BOG compressor 24 :Liquid inlet 25:Liquid outlet 26: Gas outlet 61: Pump 62:BOG cooler 100: Liquid hydrogen 300: Boil-off gas

Claims

1. Compressing the boil-off gas of liquid hydrogen flowing out of the tank to a predetermined post-compression pressure that exceeds the critical pressure of hydrogen using a compressor; cooling the boil-off gas that has been compressed into a supercritical fluid state to a temperature lower than the critical temperature of hydrogen; Pressurizing the boil-off gas that has been cooled to a compressible liquid state by a pump to a predetermined post-compression pressure that exceeds the critical pressure of hydrogen and is higher than the post-compression pressure; Combining the boil-off gas that has been pressurized to a supercritical fluid state again with the liquid hydrogen discharged from the tank, or combining the vaporized boil-off gas that has been pressurized to a supercritical fluid state again with the vaporized liquid hydrogen discharged from the tank. Liquid hydrogen dispensing method.

2. cooling the boil-off gas in a supercritical fluid state includes exchanging heat between the boil-off gas in a supercritical fluid state and the liquid hydrogen in a surface heat exchanger; The method for dispensing liquid hydrogen according to claim 1.

3. The pressure after compression is higher than 1.185 MPaG and not higher than 2.5 MPaG; 3. The method for dispensing liquid hydrogen according to claim 1 or 2.

4. The pressure after compression is higher than 1.185 MPaG and not higher than 1.5 MPaG, 3. The method for dispensing liquid hydrogen according to claim 1 or 2.

5. a tank having a liquid inlet, a liquid outlet, and a gas outlet, in which liquid hydrogen is stored; a receiving line connected to the liquid inlet of the tank through which the liquid hydrogen to be received into the tank flows; a delivery line through which the liquid hydrogen delivered from the tank flows, the delivery line including, in order from upstream, a first pump connected to the liquid outlet of the tank and pressure-feeding the liquid hydrogen downstream, and a first vaporizer that vaporizes the liquid hydrogen; a BOG line connected to the gas outlet of the tank and into which boil-off gas generated by vaporization of the liquid hydrogen in the tank flows, The BOG line includes, in order from the upstream side, a BOG compressor that compresses the boil-off gas to a predetermined post-compression pressure that exceeds the critical pressure of hydrogen, a cooler that cools the boil-off gas that has become a supercritical fluid state by compression to a temperature lower than the critical temperature of hydrogen, a second pump that pressurizes the boil-off gas that has become a compressible liquid state by cooling to a predetermined post-compression pressure that exceeds the critical pressure of hydrogen and is higher than the post-compression pressure, and a second vaporizer that vaporizes the boil-off gas that has become a supercritical fluid state again by pressurization, and is connected to the discharge line downstream of the second pump. Tank equipment.

6. the cooler is a surface heat exchanger that exchanges heat between the liquid hydrogen flowing through the discharge line and the boil-off gas flowing through the BOG line. The tank facility according to claim 5.

7. the post-compression pressure is substantially the same as the pressure of the liquid hydrogen flowing into the first vaporizer; The BOG line is connected to the discharge line at the inlet of the first vaporizer, and the second vaporizer is shared with the first vaporizer.

7. The tank facility according to claim 5 or 6.

8. The pressure after compression is higher than 1.185 MPaG and not higher than 2.5 MPaG; The tank facility according to any one of claims 5 to 7.

9. The pressure after compression is higher than 1.185 MPaG and not higher than 1.5 MPaG, The tank facility according to any one of claims 5 to 7.

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