Rare gas production system and liquefied hydrogen receiving terminal including the same

Abstract

The present invention relates to a rare gas production system capable of reducing the cost of producing rare gas, and a liquefied hydrogen receiving terminal including the same. [Solution] The rare gas production system of the present invention includes an air compressor that compresses air; an vaporizer that exchanges heat between the air compressed by the air compressor and liquefied hydrogen which is vaporized and supplied to a demand destination, cooling the compressed air and vaporizing the liquefied hydrogen; a separation tower that separates the oxygen and nitrogen condensed in the vaporizer; a hard column that condenses and separates hard components from the remaining air remaining after oxygen and nitrogen are separated from the fluid transferred from the upper discharge part of the separation tower; and a heavy column that vaporizes and separates heavy components from the remaining air remaining after oxygen and nitrogen are separated from the fluid transferred from the lower discharge part of the separation tower.

Description

[Technical field]

[0001] The present invention relates to a rare gas production system capable of reducing the cost of producing rare gas, and a liquefied hydrogen receiving terminal including the same. [Background technology]

[0002] Xenon (Xe, Xenon) and krypton (kr, krypton) are rare gases that are essential for the semiconductor manufacturing process. Xenon and krypton are contained in the air in trace amounts as colorless, odorless monoatomic molecules, and can be obtained by separating them from the air.

[0003] An Air Separation Unit separates oxygen and nitrogen from air and also produces a crude stream containing noble gases such as neon, xenon, krypton and helium, which are present in air in very small quantities.

[0004] The technology to separate rare gases such as krypton in an air separation unit began in Germany in 1969 and has a long history. However, rare gases such as krypton can only be separated by 1,000,000 m of air. 3 Approximately 1m per 3 Although only trace amounts of these elements are present, extremely low temperatures of approximately -200°C or lower are required to separate them, and low-temperature refrigerators require enormous amounts of energy. Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, liquefied hydrogen is transported by ship, loaded into storage tanks at receiving terminals, stored in liquid form, and then vaporized and sent to the consumer. Because liquefied hydrogen is stored at approximately -253°C in the storage tanks, a continuous supply of heat above room temperature is required to vaporize the liquefied hydrogen.

[0006] The present invention provides a rare gas production system and a liquefied hydrogen receiving terminal including the same, which can supply the energy required for producing rare gas by utilizing the cryogenic heat of vaporization, which is discarded while vaporizing liquefied hydrogen in the process of discharging liquefied hydrogen, in a large-scale air separation unit. [Means for solving the problem]

[0007] According to one aspect of the present invention for achieving the above-mentioned object, there is provided a rare gas production system including: an air compressor for compressing air; an evaporator for exchanging heat between the air compressed by the air compressor and liquefied hydrogen which is vaporized and supplied to a demand destination, thereby cooling the compressed air and vaporizing the liquefied hydrogen; a separation tower for separating oxygen and nitrogen condensed in the vaporizer; a hard column for condensing and separating hard components from the remaining air remaining after oxygen and nitrogen are separated from the fluid transferred from the upper discharge part of the separation tower; and a heavy column for vaporizing and separating heavy components from the remaining air remaining after oxygen and nitrogen are separated from the fluid transferred from the lower discharge part of the separation tower.

[0008] Preferably, the vaporizer, the separation tower, the hard column and the heavy column are provided in a cold box, and the system may further include a pretreatment device that recovers residual cold heat from the cold box and condenses and separates foreign matter contained in the compressed air supplied from the air compressor to the vaporizer.

[0009] Preferably, the hard components include neon and methane, and the heavy components may include xenon and krypton.

[0010] Preferably, the hard column may include a primary heat exchanger that cools the remaining air using the cold heat of the liquefied hydrogen; and a secondary heat exchanger that further cools the remaining air cooled in the primary heat exchanger using a heat medium that recovers the cold heat of the liquefied hydrogen while vaporizing the liquefied hydrogen.

[0011] Preferably, the heavy column can recover waste heat from exhaust gas discharged while producing electricity using the evaporated gas of the liquefied hydrogen, and vaporize heavy components.

[0012] Preferably, the liquid nitrogen produced in the separation column can be supplied as a refrigerant for maintaining the liquefied hydrogen in a liquid state.

[0013] Preferably, the system may further include a re-vaporizer that vaporizes the liquid oxygen or nitrogen produced in the separation tower; and a turbine-generator that includes a turbine that expands the oxygen or nitrogen vaporized in the re-vaporizer and a generator that produces electricity by using the driving force of the turbine.

[0014] Preferably, the system may further include a liquefied hydrogen storage tank for storing the liquefied hydrogen; a heat medium circulating unit for circulating a heat medium and recovering thermal energy from at least one of the liquefied hydrogen storage tank and the hard column; and a cold energy recovery device for exchanging heat between the heat medium and oxygen or nitrogen expanded in the turbine, thereby cooling the heat medium.

[0015] Preferably, the system may further include a liquefied hydrogen storage tank for storing the liquefied hydrogen; a heat medium circulating unit for circulating a heat medium and recovering thermal energy from at least one of the liquefied hydrogen storage tank and the hard column; and a fourth heat medium line for supplying the heat medium for vaporizing the liquid oxygen or nitrogen from the heat medium circulating unit to the re-vaporizer.

[0016] According to another aspect of the present invention to achieve the above-mentioned object, there is provided a liquefied hydrogen receiving terminal including: a number of liquefied hydrogen storage tanks for storing liquefied hydrogen and provided with a temperature control device for controlling an internal temperature to maintain an internal pressure at a low pressure; a liquefied hydrogen consumer receiving liquefied hydrogen from the liquefied hydrogen storage tanks; and a number of pressure tanks for receiving and storing liquefied hydrogen from the liquefied hydrogen storage tanks to be supplied to the liquefied hydrogen consumer, the pressure tanks being smaller in capacity than the liquefied hydrogen storage tanks but maintained at high pressure; the liquefied hydrogen consumer includes a vaporizer for vaporizing the liquefied hydrogen to produce gaseous hydrogen and then supplying the produced hydrogen to the gaseous hydrogen consumer; and the rare gas production system.

[0017] Preferably, the system may further include a second liquefied hydrogen supply line, which is a flow path for transporting liquefied hydrogen from the pressure tank to the vaporizer and the rare gas production system.

[0018] Preferably, the temperature control device may include a heat medium circulating unit that recovers cold energy from the liquefied hydrogen, or circulates a heat medium that supplies cold energy to the liquefied hydrogen or the rare gas production system.

[0019] Preferably, the system may further include a compressor that compresses hydrogen evaporation gas generated in the liquefied hydrogen storage tank and supplies the compressed hydrogen evaporation gas to the pressure tank so that the pressure reaches a delivery pressure for supplying liquefied hydrogen to a liquefied hydrogen demand destination from the pressure tank; an energy conversion unit that produces electricity using the evaporation gas compressed by the compressor as fuel; and a waste heat recovery line that supplies waste heat generated while producing electricity in the energy conversion unit to the heavy column. Effect of the Invention

[0020] The rare gas production system and the liquefied hydrogen receiving terminal including the same according to the present invention recover the extremely low temperature vaporization heat that is wasted when vaporizing liquefied hydrogen in the process of sending out liquefied hydrogen, and use it in a large-scale air separation unit, thereby making it possible to produce rare gases such as neon, xenon, krypton, etc., which are necessary for the semiconductor industry as well as nitrogen and oxygen.

[0021] In addition, since the storage temperature of liquefied hydrogen is approximately -253°C, by utilizing the heat of vaporization of liquefied hydrogen as refrigeration energy for the air separation unit, it is possible to separate and produce almost all components contained in air, except for helium, which has a lower liquefaction temperature than the storage temperature of liquefied hydrogen.

[0022] In addition, by utilizing the heat of vaporization of liquefied hydrogen in the air separation unit, it is possible to reduce the power consumption and production costs required for refrigerators, etc.

[0023] In addition, the liquefied nitrogen, liquefied oxygen, etc. produced in the air separation unit can be supplied to a liquefied air energy storage unit and used as an energy source to generate electricity.

[0024] In addition, by connecting an air separation unit to the liquefied hydrogen receiving terminal, the heat source required to send out liquefied hydrogen and the cold energy required to separate the air can be exchanged with each other to produce additional electricity, which can create additional profits and have a beneficial effect on energy and production costs and efficiency. [Brief description of the drawings]

[0025] [Figure 1] 1 is a simplified diagram illustrating a liquefied hydrogen receiving terminal including a rare gas production system according to one embodiment of the present invention. [Diagram 2] 1 is a simplified diagram of a rare gas production system according to one embodiment of the present invention. [Diagram 3] FIG. 1 is a simplified diagram of a liquefied air energy storage unit according to one embodiment of the present invention. BEST MODE FOR CARRYING OUT THEINVENTION

[0026] For a fuller understanding of the operating advantages and objects attained by the practice of the present invention, reference should be had to the accompanying drawings which illustrate preferred embodiments of the invention and the teachings therein.

[0027] The configuration and operation of the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings as follows. Herein, in attaching reference numerals to the components of each drawing, it should be noted that the same components are represented by the same numerals as much as possible even if they are shown in different drawings. In addition, the following embodiment can be modified into many other forms, and the scope of the present invention is not limited to the following embodiment.

[0028] Hereinafter, a rare gas production system and a liquefied hydrogen receiving terminal including the same according to an embodiment of the present invention will be described with reference to FIGS.

[0029] In explaining this embodiment, a liquefied hydrogen receiving terminal refers to a terminal that is equipped with a large number of large-capacity liquefied hydrogen storage tanks on land or at sea, receives liquefied hydrogen from transportation means such as ships, stores it, and sends out the liquefied hydrogen stored in the liquefied hydrogen storage tanks by transportation means such as ships or tank trucks, or directly to a liquefied hydrogen demand destination.

[0030] First, referring to FIG. 1, a liquefied hydrogen receiving terminal according to one embodiment of the present invention includes a number of liquefied hydrogen storage tanks 102 that store liquefied hydrogen and have at least one of a temperature maintenance unit 46 and a densification unit 45 installed therein and can control the storage temperature, liquefied hydrogen demand destinations 51, 52, 53 that receive the hydrogen stored in the liquefied hydrogen storage tanks 102, an evaporated gas treatment unit that processes evaporated gas generated by vaporizing the liquefied hydrogen, and a heat medium circulating unit 40 that recovers thermal energy of the liquefied hydrogen.

[0031] In this embodiment, the evaporative gas treatment unit includes a compressor 41 that discharges the evaporative gas from the liquefied hydrogen storage tank 102, a buffer tank 42 that stores the evaporative gas discharged from the liquefied hydrogen storage tank 102, and an energy conversion unit 47 that produces electricity using the evaporative gas discharged from the liquefied hydrogen storage tank 102.

[0032] In this embodiment, the liquefied hydrogen demand destinations 51, 52, and 53 may include a vaporizer 52 that vaporizes liquefied hydrogen and then supplies it to the gaseous hydrogen demand destination, and a rare gas production system 53 that separates air while recovering thermal energy at the liquefied hydrogen receiving base, such as the cold heat of the liquefied hydrogen, the cold heat and hot heat of the heat medium circulation unit 40, and the waste heat of the energy conversion unit 47, to produce nitrogen, oxygen, and one or more rare gases. The liquefied hydrogen demand destinations 51, 52, and 53 may further include a liquefied hydrogen storage base 51 that receives and stores liquefied hydrogen for the purpose of transporting the liquefied hydrogen, such as a land terminal, a ship, or a land trailer.

[0033] In vaporizer 52, heat is directly or indirectly exchanged between liquefied hydrogen to be sent to liquefied hydrogen demand destinations 51, 52, 53 and air for producing each active component such as oxygen in rare gas production system 53. The liquefied hydrogen is vaporized while exchanging heat in vaporizer 52, and at least a portion of the specific components contained in the air is condensed, so that the condensed components can be separated from the air.

[0034] Referring to Figures 1 and 2, the rare gas production system 53 of this embodiment includes an air compressor 62 that compresses air, and a pre-treatment device 63 that removes impurities contained in the air compressed by the air compressor 62.

[0035] A knockout drum 61 may be provided upstream of the air compressor 62 to separate the liquid phase contained in the air entering the air compressor 62 and allow only gaseous air to flow into the air compressor 62.

[0036] In the pretreatment device 63, impurities contained in the compressed air, such as moisture (H2O) and carbon dioxide (CO2), can be removed.

[0037] The pre-treatment device 63 may include a condenser (not shown) for condensing impurities contained in the gaseous compressed air. The condenser of the pre-treatment device 63 may utilize residual cold energy from the cold box 60 (described later), recover the residual cold energy, and condense the impurities before separating them from the compressed air.

[0038] The compressed air from which impurities have been removed in the pretreatment device 63 can be heat exchanged with liquefied hydrogen while being supplied to the above-mentioned vaporizer 52. While exchanging heat with liquefied hydrogen in the vaporizer 52, a portion of the compressed air, in particular, certain components, can be condensed.

[0039] The rare gas production system of this embodiment includes a separation tower 54 that produces liquid nitrogen and liquid oxygen by a fractional distillation process from compressed air that has been cooled by heat exchange with liquefied hydrogen in a vaporizer 52, a hard column 55 that separates components with low specific gravity from the air remaining after the liquefied nitrogen and liquefied oxygen are separated in the separation tower 54, and a heavy column 56 that separates components with high specific gravity from the air remaining after the liquefied nitrogen and liquefied oxygen are separated in the separation tower 54.

[0040] The liquid nitrogen and oxygen separated in the separation tower 54 are stored in separate storage tanks (not shown). The liquid nitrogen and oxygen stored in the storage tanks can be sold to various consumers.

[0041] In addition, the rare gas production system according to this embodiment may further include a liquefied air energy storage (LAES) unit LS that produces electricity using the remaining liquid nitrogen or liquid oxygen remaining after the liquid nitrogen or liquid oxygen is sold to a consumer.

[0042] Referring to FIG. 3, in this embodiment, an example is described in which liquid oxygen produced in the vaporizer 52 is supplied to the liquefied air energy storage unit LS via the liquid air line AL, but liquid nitrogen may also be supplied to the liquefied air energy storage unit LS.

[0043] The liquefied air energy storage unit LS of this embodiment includes a liquefied air storage vessel S that stores liquid oxygen received from the rare gas production system, a pump P that discharges liquid oxygen from the liquefied air storage vessel S, a re-vaporizer V that vaporizes the liquefied oxygen pressurized by the pump P, and a turbine-generator T that uses the air re-vaporized in the re-vaporizer V as a working fluid to drive a turbine and produces electricity using the rotational force of the turbine.

[0044] According to this embodiment, the liquid nitrogen or liquid oxygen produced in the rare gas production system 53 can be supplied as a working fluid to the liquefied air energy storage unit LS to produce additional electricity.

[0045] In the re-vaporizer V of this embodiment, the high-temperature heat medium is cooled and the liquid oxygen is vaporized by heat exchange between the liquid oxygen supplied to the re-vaporizer V along the liquid air line AL and the high-temperature heat medium transferred from the heat medium circulation unit 40 along the fourth heat medium line ML5. In other words, the heat of vaporization of the liquid oxygen can be utilized as a refrigerant for cooling the heat medium circulating in the heat medium circulation unit 40.

[0046] In addition, according to the present embodiment, a cold heat recovery device (not shown) may be further included, which performs heat exchange between the re-vaporized oxygen expanded while driving the turbine-generator T and the high-temperature heat medium supplied to the heat medium circulating unit 40, and pre-cools the high-temperature heat medium supplied to the heat medium circulating unit 40.

[0047] In this way, by recovering the cold energy of the revaporized oxygen, the cooling load of the heat medium circulating section 40 can be reduced.

[0048] 2, the rigid column 55 of this embodiment is connected to the top discharge of the separation tower 54 by a rigid line GL. The fluid discharged from the top of the separation tower 54 is transferred to the rigid column 55 through the rigid line GL.

[0049] The fluid transferred to the rigid column 55 via the rigid line GL is a mixture of residual nitrogen and substances with low specific gravity such as neon (Ne), helium (He) and methane (CH4) in the gas phase.

[0050] The hard column 55 may be provided with a primary heat exchange section (not shown) that primarily cools the fluid that has flowed into the hard column 55 via the hard line GL by heat exchange with liquefied hydrogen received from the liquefied hydrogen storage tank 102 or the pressure tank 100 described later via the second liquefied hydrogen supply line SL2, and a secondary heat exchange section (not shown) that secondarily cools the fluid primarily cooled in the primary heat exchange section by heat exchange with an extremely low temperature heat medium received from the heat medium circulation section 40 via the third heat medium line ML4.

[0051] In the primary heat exchange section, the fluid can be cooled to approximately 20 K by the cold energy of the liquefied hydrogen transferred via the second liquefied hydrogen supply line SL2. In the secondary heat exchange section, the fluid can be cooled to approximately 10 K or lower by the cold energy of the cryogenic heat medium transferred via the third heat medium line ML4.

[0052] During this process, neon and methane may be condensed and separated, and the separated liquid neon and methane may be stored in separate storage tanks.

[0053] Heavy column 56 is connected to the bottom discharge of separation tower 54 by heavy line HL. Fluid discharged from the bottom of separation tower 54 is transferred to heavy column 56 via heavy line HL.

[0054] The fluid transferred to the heavy column 56 via the heavy line HL is a mixture of residual nitrogen and components with high specific gravity such as xenon (Xe) and krypton (kr) in a liquid phase.

[0055] In the heavy column 56, the fluid flowing into the heavy column 56 via the heavy line HL can be heated using the waste heat of the exhaust gas transferred from the energy conversion section 47 via the waste heat supply line EL. The waste heat of the exhaust gas can be used to vaporize the residual nitrogen in liquid state, thereby obtaining xenon and krypton in liquid phase.

[0056] In addition, the xenon and krypton produced in the heavy column 56 can be stored in separate storage tanks and sold to various consumers.

[0057] Since the rare gas production system 53 according to this embodiment is installed at a liquefied hydrogen receiving terminal, there is no need to provide separate infrastructure capable of supplying each product, such as liquid nitrogen, oxygen, neon, xenon, and krypton, produced in the rare gas production system 53 to each consumer.

[0058] In this embodiment, the pretreatment device 63 , the vaporizer 52 , the separation column 54 , the hard column 55 and the heavy column 56 may be provided in a cold box 60 .

[0059] As described above, the pre-treatment device 63 can utilize the residual cold energy in the cold box 60 to condense the foreign matter. Therefore, the pre-treatment device 63 can condense and remove foreign matter such as moisture and carbon dioxide contained in the compressed air by utilizing the residual cold energy of hydrogen that has been vaporized or has been heated while cooling the fluid in the vaporizer 52 or the separation tower 54.

[0060] In this way, according to the present invention, the heat of vaporization of cryogenic liquefied hydrogen that is discarded at a liquefied hydrogen receiving terminal can be recovered, and nitrogen and oxygen contained in the air can be separated and produced in a liquid state.

[0061] In addition, the thermal energy generated at the liquefied hydrogen receiving terminal, specifically, the waste heat from the exhaust gas in the energy conversion section 47 and the cold heat of the heat medium in an extremely low temperature state cooled in the heat medium circulation section 40 can be further recovered to obtain rare gases such as neon and xenon.

[0062] In addition, the produced liquid oxygen or nitrogen can be used to drive a turbine to produce additional electricity, and the liquid oxygen or nitrogen can also be used as a refrigerant to cool the heat medium in the heat medium circulator 40.

[0063] Therefore, according to the present invention, in separating and producing many gas components such as nitrogen, oxygen, and neon from air, no power required for cooling is required, so that production costs can be reduced.

[0064] On the other hand, the liquefied hydrogen storage tank 102 of this embodiment has a capacity of 100 m 3 At least two or more of the above large-capacity storage tanks may be provided. The operating pressure of the liquefied hydrogen storage tank 102 may be 0.1 bar to 6 bar, and is preferably maintained at 3 bar or less, and more preferably at 1 bar or less or at normal pressure.

[0065] In addition, the liquefied hydrogen storage tank 102 may be operated in either a low temperature mode in which the liquid hydrogen storage tank 102 is maintained at a first temperature, or a high temperature mode in which the liquid hydrogen storage tank 102 is maintained at a second temperature higher than the first temperature.

[0066] In this embodiment, the first temperature may be a densification temperature for increasing the density of the stored liquefied hydrogen, which may be a temperature range in which the liquefied hydrogen exists in a mixed state of solid and liquid, i.e., about 14 K to 21 K. At least a portion of the liquefied hydrogen stored in the liquefied hydrogen storage tank 102 in the low temperature mode may exist in a solid state having a higher density than liquid, and therefore the liquefied hydrogen stored in the liquefied hydrogen storage tank 102 may exist in a liquid state, a two-phase mixed state of liquid and solid, or a three-phase mixed state of liquid, solid, and gas, preferably in a slush state.

[0067] In this embodiment, the second temperature may be a temperature above the triple point temperature of the liquefied hydrogen, and when the liquefied hydrogen storage tank 102 is maintained at the second temperature, the temperature of the hydrogen in the storage tank may be maintained at a temperature slightly above or about 21 K. When the liquefied hydrogen storage tank 102 is operated in a high temperature mode, the hydrogen stored in the liquefied hydrogen storage tank 102 may exist in a liquid state, a gaseous state, or a two-phase mixture of liquid and gas.

[0068] The temperature maintaining unit 46 and the densification unit 45 of the liquefied hydrogen storage tank 102 are connected to the heat medium circulating unit 40 by a first heat medium line ML2. The extremely low temperature heat medium cooled in the heat medium circulating unit 40 is transferred to the temperature maintaining unit 46 and the densification unit 45 along the first heat medium line ML2, and the heat medium whose temperature is increased while cooling the liquid hydrogen in the temperature maintaining unit 46 and the densification unit 45 may be returned to the heat medium circulating unit 40 along the first heat medium line ML2, or may be returned to the heat medium circulating unit 40 in a state where its temperature is reduced while heating the fluid in the heavy column 56.

[0069] The heat medium circulating unit 40 of this embodiment supplies an extremely low temperature heat medium to the liquefied hydrogen storage tank 102 when the liquefied hydrogen storage tank 102 is operated in low temperature mode, transfers the cold heat to the hydrogen stored in the liquefied hydrogen storage tank 102, and then receives the high temperature heat medium.

[0070] In addition, when the liquefied hydrogen storage tank 102 is operated in high temperature mode, the heat medium circulation unit 40 supplies a high-temperature heat medium to the liquefied hydrogen storage tank 102, recovers the cold heat of the hydrogen stored in the liquefied hydrogen storage tank 102, and receives an extremely low-temperature heat medium.

[0071] In this embodiment, the heat medium circulating through the heat medium circulating section 40 may be helium or another medium that indirectly transfers thermal energy between helium and the liquefied hydrogen stored in the liquefied hydrogen storage tank 102.

[0072] In this embodiment, the low temperature mode can be used for the purpose of suppressing the reactivity of the liquefied hydrogen stored in the liquefied hydrogen storage tank 102 and stably storing hydrogen while maintaining it in a liquid state. When a portion of the liquefied hydrogen begins to solidify, the ortho-para conversion reaction of the liquefied hydrogen is suppressed, thereby preventing the liquefied hydrogen from changing into a gas phase and preventing the diffusion of vaporization, thereby stabilizing the liquefied hydrogen.

[0073] The liquefied hydrogen stored in the liquefied hydrogen storage tank 102 by the densification unit 45 may exist partially in a slurry state. By solidifying only a portion of the stored liquefied hydrogen, rather than the entirety of it, the hydrogen can be stored in a solid state that partially retains more cold heat, maximizing the retained latent heat, and stably storing the hydrogen.

[0074] In addition, since a portion of the liquefied hydrogen exists in a solid state, it acts as a shield and prevents the liquefied hydrogen from evaporating. Through this operation, the internal pressure of the liquefied hydrogen storage tank 102 can be maintained at 1 bar or less.

[0075] The high temperature mode may be implemented for the purpose of supplying fuel for producing electricity in the energy conversion unit 47 by vaporizing a portion of the liquefied hydrogen stored in the liquefied hydrogen storage tank 102 and inducing the generation of a certain amount of evaporated gas. In addition, a heat medium may be used to recover cold energy from the liquefied hydrogen in the liquefied hydrogen storage tank 102 operated in the high temperature mode to be supplied to the liquefied hydrogen storage tank 102 operated in the low temperature mode or the rare gas production system 53.

[0076] In the high temperature mode of this embodiment, when a high temperature heat medium is supplied to the temperature maintaining unit 46, a vaporization reaction begins. When gaseous nitrogen or methane is compressed and then Joule-Thomson expanded, the temperature decreases and it is liquefied, but gaseous hydrogen or helium has a lower inversion temperature than room temperature, so the temperature actually increases when it is expanded at room temperature. Therefore, when hydrogen is expanded below the inversion temperature, the temperature decreases.

[0077] In this embodiment, the internal temperature of the liquefied hydrogen storage tank 102 operated in high temperature mode is maintained at a temperature higher than 20K but lower than the inversion temperature, creating a vacuum inside the liquefied hydrogen storage tank 102 and promoting conversion to para-hydrogen, while at the same time supplying and discharging evaporated gas, thereby controlling the pressure of the liquefied hydrogen storage tank 102 and the amount of evaporated gas generated. Through this operation, the internal pressure of the liquefied hydrogen storage tank 102 can be maintained at 3 bar or less.

[0078] Hydrogen has the characteristic that the heat of conversion generated during the ortho-para conversion reaction is greater than the latent heat of vaporization of liquefied hydrogen, so the heat of conversion causes the liquefied hydrogen to evaporate. Due to this characteristic, hydrogen evaporation gas is generated irregularly, such as instantaneous chain reaction generation and then a sudden decrease in the amount generated as the reaction stops.

[0079] According to this embodiment, the liquefied hydrogen storage tank 102 can be operated in a high temperature mode and a low temperature mode, and the amount of evaporated gas generated can be adjusted to a constant amount.

[0080] In the liquefied hydrogen receiving terminal according to the present embodiment, hydrogen evaporation gas (or vaporized gas) can be used as fuel to generate electricity to be utilized within the system. At least one of the multiple liquefied hydrogen storage tanks 102 operates in high temperature mode to continuously generate a certain amount of hydrogen evaporation gas and supply the evaporation gas to the energy conversion unit 47, thereby stably producing and supplying electricity.

[0081] Meanwhile, in this embodiment, when it is time to discharge the evaporated gas in the liquefied hydrogen storage tank 102, the evaporated gas is discharged by operating the compressor 41. The liquefied hydrogen storage tank 102 and the compressor 41 are connected by an evaporated gas supply line BL2, and the evaporated gas generated in the liquefied hydrogen storage tank 102 can flow into the compressor 41 after being discharged through the evaporated gas supply line BL2.

[0082] Meanwhile, the compressor 41 of this embodiment can operate to supply and exhaust the evaporated gas from the liquefied hydrogen storage tank 102 to create a medium vacuum state when the evaporated gas in the liquefied hydrogen storage tank 102 is explosively generated.

[0083] When the compressor 41 is operating and the liquefied hydrogen storage tank 102 reaches a medium vacuum state, an ortho-para conversion reaction occurs in the liquefied hydrogen storage tank 102, and when the ratio of para hydrogen becomes high, the operation of the compressor 41 is stopped and the vacuum in the liquefied hydrogen storage tank 102 is released, thereby stabilizing the liquefied hydrogen storage tank 102.

[0084] The evaporated gas discharged from the liquefied hydrogen storage tank 102 may be transported to the buffer tank 42 via the first evaporated gas distribution line CL1 and then stored in the buffer tank 42, or may be transported to the energy conversion section 47 via the second evaporated gas distribution line CL2.

[0085] In this embodiment, the energy conversion unit 47 may include at least one of a fuel cell that uses hydrogen as fuel to produce electricity through an electrochemical reaction, and a turbine generator that uses hydrogen as a working fluid to drive a turbine and produces electricity by converting the turbine's driving energy into electricity.

[0086] The electricity generated in the energy conversion unit 47 in this embodiment may be used in the heat medium circulation unit 40 and the rare gas production system 53, or may be distributed and supplied to electricity demand destinations on the ship by a power distribution means (not shown) such as a switchboard (not shown).

[0087] In addition, according to this embodiment, the system may further include two or more pressure tanks 100 which are smaller in capacity than the liquefied hydrogen storage tank 102 but operated at high pressure and store liquefied hydrogen to be supplied to liquefied hydrogen demand destinations 51, 52, 53, liquefied hydrogen supply lines SL1, SL2 which connect the pressure tanks 100 to the liquefied hydrogen demand destinations 51, 52, 53 and transport the liquefied hydrogen from the pressure tanks 100 to the liquefied hydrogen demand destinations 51, 52, 53, and recovery lines RL1, RL2, RL3, RL4, RL5 which recover evaporated gas from the pressure tanks 100 and the liquefied hydrogen demand destinations 51, 52, 53.

[0088] The operating pressure of the pressure tank 100 of this embodiment can be maintained at a higher pressure than the operating pressure of the liquefied hydrogen storage tank 102, which operates at 3 bar or less. For example, the pressure tank 100 of this embodiment may be operated at 6 bar or more, 8 bar or more, or 10 bar or more.

[0089] Meanwhile, since the operating pressure of the pressure tank 100 is higher than the operating pressure of the liquefied hydrogen storage tank 102, a supply pump 50 for pressurizing and supplying liquefied hydrogen from the liquefied hydrogen storage tank 102 to the pressure tank 100 may be provided in the liquefied hydrogen discharge line LL connecting the liquefied hydrogen storage tank 102 and the pressure tank 100. In this case, the liquefied hydrogen is transferred to the pressure tank 100 after being pressurized by the supply pump 50.

[0090] The pressure tank 100 of this embodiment may be disposed at a position lower than the height of the liquefied hydrogen storage tank 102. Therefore, the supply pump 50 can be omitted as an optional configuration, and the liquefied hydrogen can be transferred from the liquefied hydrogen storage tank 102 to the pressure tank 100 by the height difference without providing additional power such as the supply pump 50.

[0091] According to this embodiment, before transferring liquefied hydrogen from the liquefied hydrogen storage tank 102 to the pressure tank 100, it can be pre-cooled using liquefied hydrogen discharged from the liquefied hydrogen storage tank 102 through the liquefied hydrogen discharge line LL connecting the liquefied hydrogen storage tank 102 and the pressure tank 100. When the supply pump 50 is provided, the cavitation phenomenon of the supply pump 50 can be prevented by pre-cooling both the liquefied hydrogen discharge line LL and the supply pump 50.

[0092] As a means for pre-cooling the liquefied hydrogen discharge line LL, a liquefied hydrogen recovery line LL1 may be further included which branches off from the pressure tank 100 or the portion where the pressure tank 100 and the liquefied hydrogen discharge line LL meet, i.e., upstream of the header, and then merges upstream of the supply pump 50 or the portion where the liquefied hydrogen storage tank 102 and the liquefied hydrogen discharge line LL meet, i.e., downstream of the header, and recirculates the liquefied hydrogen with an increased temperature to the upstream of the liquefied hydrogen discharge line LL while pre-cooling the liquefied hydrogen discharge line LL.

[0093] In this embodiment, the internal pressure of the pressure tank 100 is maintained at 8 bar or 10 bar or more, and the operating pressure of the liquefied hydrogen demand destinations 51, 52, 53 can be maintained at a pressure lower than 8 bar or 10 bar, preferably 3 bar or less.

[0094] The internal pressure of the pressure tank 100 can be maintained by compressing the evaporated gas discharged from the liquefied hydrogen storage tank 102 and then supplying it to the pressure tank 100. To prevent the pressure of the pressure tank 100 from becoming lower than the operating pressure, the high-pressure evaporated gas stored in the buffer tank 42 can be supplied to the pressure tank 100 preferentially from the energy conversion unit 47.

[0095] The supply of liquefied hydrogen from the pressure tank 100 to liquefied hydrogen demand destinations 51, 52, 53 can be carried out by sending liquefied hydrogen from the pressure tank 100 to the first liquefied hydrogen supply line SL1 and the second liquefied hydrogen supply line SL2 using the pressure of the liquefied hydrogen transferred from the liquefied hydrogen storage tank 102 to the pressure tank 100 along the liquefied hydrogen discharge line LL, or the pressure of the high-pressure evaporated gas itself transferred from the buffer tank 42 via the third evaporated gas distribution line CL3.

[0096] The third evaporated gas distribution line CL3 is a flow path for high-pressure evaporated gas that connects the buffer tank 42 and the pressure tank 100, and is a means for maintaining the internal pressure of the pressure tank 100. The high-pressure evaporated gas compressed by the compressor 41, or the high-pressure evaporated gas stored in the buffer tank 42 after being compressed by the compressor 41, is transferred to the pressure tank 100 via the third evaporated gas distribution line CL3.

[0097] In this embodiment, when the high-pressure evaporated gas transported through the third evaporated gas distribution line CL3 is insufficient to maintain the internal pressure of the pressure tank 100, the internal pressure of the pressure tank 100 can be maintained by vaporizing and supplying the liquefied hydrogen stored in the pressure tank 100.

[0098] As a means for maintaining the internal pressure of the pressure tank 100, a second heat medium line ML3 connecting the pressure tank 100 and the heat medium circulation section 40, and a fifth recovery line RL5 connecting the pressure tank 100 and the upstream of the compressor 41 may be further included.

[0099] The high-temperature heat medium is transferred from the heat medium circulation unit 40 to the pressure tank 100 via the second heat medium line ML3, and the low-temperature heat medium that has recovered cold energy while vaporizing the liquefied hydrogen stored in the pressure tank 100 is recovered again to the heat medium circulation unit 40 via the second heat medium line ML3.

[0100] When the heat medium is circulated through the second heat medium line ML3 and evaporated gas is generated in the pressure tank 100, the internal pressure of the pressure tank 100 increases, so that the operating pressure of the pressure tank 100 can be maintained.

[0101] In addition, the operating pressure of the pressure tank 100 can be maintained by discharging the evaporative gas through the fifth recovery line RL5, supplying it upstream of the compressor 41, compressing the evaporative gas in the compressor 41, and then supplying it to the pressure tank 100 in the form of high-pressure evaporative gas.

[0102] The second heat medium line ML3 connecting the pressure tank 100 and the heat medium circulating unit 40, a header at which the second heat medium line ML3 is connected to the pressure tank 100 and the heat medium circulating unit 40, and various devices such as a heat exchanger and a valve that may be installed on the second heat medium line ML3 are installed in a cold box to perform primary vacuum insulation.

[0103] The cold box may be equipped with a hydrogen detector for detecting hydrogen leakage. Also, a heat insulating material may be installed on the outside of the cold box to provide secondary insulation.

[0104] In this embodiment, the liquefied hydrogen storage base 51 receives liquefied hydrogen via a first liquefied hydrogen supply line SL1 that connects the pressure tank 100 and the liquefied hydrogen storage base 51, and the vaporizer 52 and the rare gas production system 53 can receive liquefied hydrogen via a second liquefied hydrogen supply line SL2 that connects the pressure tank 100 with the vaporizer 52 and the rare gas production system 53.

[0105] On the other hand, before the liquefied hydrogen is transferred to the liquefied hydrogen demand destinations 51, 52, 53, the liquefied hydrogen supply lines SL1, SL2 can be pre-cooled using liquefied hydrogen stored in the pressure tank 100 or the liquefied hydrogen storage tank 102.

[0106] The evaporated gas vaporized while pre-cooling the liquefied hydrogen supply lines SL1, SL2 may be recovered in the pressure tank 100 via a third recovery line RL3 connected to the pressure tank 100, or may be recovered in the compressor 41 via a fourth recovery line RL4 connected to the compressor 41.

[0107] The evaporated gas vaporized while pre-cooling the first liquefied hydrogen supply line SL1 is recovered in the third recovery line RL3 and the fourth recovery line RL4 via the first recovery line RL1, and the evaporated gas vaporized while pre-cooling the second liquefied hydrogen supply line SL2 is recovered in the third recovery line RL3 and the fourth recovery line RL4 via the second recovery line RL2.

[0108] On the other hand, while liquefied hydrogen is supplied to the liquefied hydrogen demand destinations 51, 52, 53, evaporated gas generated at the liquefied hydrogen demand destinations 51, 52 and exceeding the allowable pressure of the liquefied hydrogen demand destinations 51, 52 can also be recovered in the compressor 41 via the first to fourth recovery lines RL1 to RL4.

[0109] The evaporated gas recovered upstream of the compressor 41 via the fourth recovery line RL4 and the fifth recovery line RL5 may be compressed by the compressor 41 and then stored in the buffer tank 42, or may be recovered in the pressure tank 100 and then used to maintain the internal pressure of the pressure tank 100.

[0110] In addition, the evaporated gas recovered from the liquefied hydrogen demand destinations 51, 52, 53 via the fourth recovery line RL4 and the fifth recovery line RL5 may be supplied to the energy conversion unit 47 via the second evaporated gas distribution line CL2 connected to the energy conversion unit 47, and then used to generate electricity.

[0111] On the other hand, the heat of vaporization generated while the liquefied hydrogen is vaporized in the vaporizer 52 may be recovered via the rare gas production system 53.

[0112] In addition, waste heat generated while producing electricity in the energy conversion unit 47 can be received through a waste heat supply line EL connecting the energy conversion unit 47 and the rare gas production system 53, and then used as thermal energy required for separating air. The temperature of the thermal energy transferred through the waste heat supply line EL may be about 500°C to 600°C.

[0113] The liquefied hydrogen receiving terminal of this embodiment maintains the pressure of the pressure tank 100 by using the evaporated gas generated during the loading and unloading of liquefied hydrogen, and can be used to generate the pressure for sending the liquefied hydrogen to liquefied hydrogen demand destinations 51, 52, and 53, and can also be used as fuel for producing electricity in the energy conversion unit 47.

[0114] In addition, during the process of loading and unloading liquefied hydrogen, the pressure in the pressure tank 100 can be maintained while effectively utilizing the cold heat and waste heat of the liquefied hydrogen to the maximum extent possible.

[0115] Furthermore, according to this embodiment, liquefied hydrogen can be supplied from any one of the two or more pressure tanks 100 to a liquefied hydrogen demand destination, while at the same time another pressure tank 100 can be filled with liquefied hydrogen.

[0116] It will be obvious to those having ordinary skill in the art to which the present invention pertains that the present invention is not limited to the above-described embodiments, and that the present invention can be implemented with various modifications or variations without departing from the technical gist of the present invention. [Explanation of symbols]

[0117] 100 Pressure Tank 102 Liquefied hydrogen storage tank 40 Heat medium circulation section 41 Compressor 42 Buffer Tank 45 High density section 46 Temperature maintenance section 47 Energy Conversion Department 50 Supply Pump 51 Liquefied Hydrogen Storage Station 52 Carburetor 53 Rare Gas Production System 54 Separation tower 55 Hard Column 56 Heavy Column 60 Cold Box 61 Knockout Drum 62 Air Compressor BL2 Evaporative gas supply line LL Liquid hydrogen discharge line CL1, CL2, CL3 Evaporative gas distribution lines LL1 Liquefied hydrogen recovery line ML2, ML3, ML4, ML5 Heat Transfer Medium Line EL waste heat supply line RL1, RL2, RL3, RL4, RL5 Collection Lines GL Hard Line SL1, SL2 liquefied hydrogen supply lines HL Heavy Line LS Liquefied Air Energy Storage Unit AL Liquid Air Line S Liquefied air storage tank P-Pump V Recarburetor T Turbine-generator

Claims

1. An air compressor that compresses air; A vaporizer that exchanges heat between the air compressed by the aforementioned air compressor and liquefied hydrogen to be supplied to the customer while being vaporized, thereby cooling the compressed air and vaporizing the liquefied hydrogen; A separation tower for separating the oxygen and nitrogen condensed in the aforementioned vaporizer; A light column that cools the residual air discharged in gaseous form from the upper discharge section of the separation tower to condense the light components, including at least one of neon and helium, contained in the residual air, and separates the light components from gaseous nitrogen; and A noble gas production system comprising: a heavy column for heating residual air discharged in liquid form from the lower discharge section of the separation tower to vaporize heavy components, including at least one of xenon and krypton, contained in the residual air, and separating the heavy components from liquid nitrogen;

2. The vaporizer, separation tower, light column, and heavy column are housed in a cold box. A noble gas production system according to claim 1, further comprising: a pretreatment device for recovering residual cold energy from the cold box and condensing and separating foreign matter contained in the compressed air supplied from the air compressor to the vaporizer;

3. The aforementioned light column is A primary heat exchange unit that cools the residual air using the cold energy of the liquefied hydrogen; and A noble gas production system according to claim 1, further comprising: a secondary heat exchange unit that further cools the residual air cooled in the primary heat exchange unit using a heat transfer medium from which the cold energy of the liquefied hydrogen is recovered while the liquefied hydrogen is vaporized;

4. The aforementioned heavy column is The noble gas production system according to claim 1, wherein the system recovers waste heat from exhaust gases while producing electricity using the evaporated liquefied hydrogen gas, and vaporizes heavy components.

5. The noble gas production system according to claim 1, wherein liquid nitrogen produced in the separation tower is supplied as a refrigerant to maintain the liquid hydrogen in a liquid state.

6. A revaporizer for vaporizing the liquid oxygen or nitrogen produced in the separation tower; and A rare gas production system according to claim 1, further comprising a turbine-generator including a turbine for expanding oxygen or nitrogen vaporized in the revaporizer, and a generator for producing electricity using the driving force of the turbine.

7. A liquefied hydrogen storage tank for storing the aforementioned liquefied hydrogen; A heat transfer medium circulation unit that circulates the heat transfer medium and recovers thermal energy from one or more of the liquefied hydrogen storage tank and the light column; and A noble gas production system according to claim 6, further comprising a cold energy recovery device for exchanging heat between oxygen or nitrogen expanded by the turbine and the heat transfer medium, thereby cooling the heat transfer medium.

8. A liquefied hydrogen storage tank for storing the aforementioned liquefied hydrogen; A heat transfer medium circulation unit that circulates the heat transfer medium and recovers thermal energy from one or more of the liquefied hydrogen storage tank and the light column; and The noble gas production system according to claim 6, further comprising: a fourth heat transfer fluid line that supplies a heat transfer fluid for vaporizing the liquid oxygen or nitrogen from the heat transfer fluid circulation unit to the revaporizer;

9. A number of liquefied hydrogen storage tanks equipped with temperature control devices to regulate the internal temperature in order to store liquefied hydrogen and maintain a low internal pressure; Liquefied hydrogen consumers who receive liquefied hydrogen from the aforementioned liquefied hydrogen storage tank; and Numerous pressure tanks that receive and store liquefied hydrogen to be supplied to liquefied hydrogen consumers from the aforementioned liquefied hydrogen storage tank, and maintain a high pressure despite having a smaller capacity than the aforementioned liquefied hydrogen storage tank; Includes, The aforementioned customers for liquefied hydrogen are: A vaporizer that vaporizes the aforementioned liquefied hydrogen to produce gaseous hydrogen, which is then supplied to a gaseous hydrogen demander; and A liquefied hydrogen receiving station comprising a noble gas production system according to any one of claims 1 to 8.

10. A liquefied hydrogen receiving station according to claim 9, further comprising: a second liquefied hydrogen supply line which is a channel through which liquefied hydrogen is transferred from the pressure tank to the vaporizer and the noble gas production system;

11. A liquefied hydrogen receiving station according to claim 9, further comprising: a temperature control device for recovering the cold energy of the liquefied hydrogen, or a heat transfer medium circulation unit for circulating a heat transfer medium that supplies cold energy to the liquefied hydrogen or the noble gas production system;

12. A compressor that compresses the hydrogen vapor gas generated in the aforementioned liquefied hydrogen storage tank and then supplies it to the pressure tank at a pressure that allows for the supply of liquefied hydrogen to a liquefied hydrogen demand destination from the pressure tank; An energy conversion unit that produces electricity using the evaporated gas compressed by the compressor as fuel; and A liquefied hydrogen receiving station according to claim 9, further comprising: a waste heat recovery line that supplies waste heat generated while producing electricity in the energy conversion section to the heavy column;

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