KR102909174B1 - rare gas production system and liquefied hydrogen receiving terminal connected to the system - Google Patents

Abstract

The present invention relates to a rare gas production system capable of reducing the cost of producing rare gases and a liquefied hydrogen receiving station including the same.
A rare gas production system according to the present invention comprises: an air compressor for compressing air; a vaporizer for heat-exchanging compressed air from the air compressor with liquefied hydrogen to be vaporized and supplied to a demander, thereby cooling the compressed air and vaporizing the liquefied hydrogen; a separation tower for separating oxygen and nitrogen condensed in the vaporizer; a light column for condensing and separating light components from residual air remaining after oxygen and nitrogen are separated from a fluid transferred from an upper discharge portion of the separation tower; and a heavy column for vaporizing and separating heavy components from residual air remaining after oxygen and nitrogen are separated from a fluid transferred from a lower discharge portion of the separation tower.

Description

Rare gas production system and liquefied hydrogen receiving terminal connected to the system

The present invention relates to a rare gas production system capable of reducing the cost of producing rare gases and a liquefied hydrogen receiving station including the same.

Xenon (Xe) and krypton (Kr) are noble gases essential in semiconductor manufacturing processes. Xenon and krypton are colorless, odorless, monoatomic molecules found in trace amounts in the air, and can be obtained by separating them from the air.

The Air Separation Unit separates oxygen and nitrogen from air, and also produces a crude stream containing rare gases such as neon, xeon, krypton, and helium, which are present in trace amounts in air.

The technology for separating rare gases like krypton in air separation units has a long history, having originated in Germany in 1969. However, even though rare gases like krypton are present in extremely small quantities—only about 1 m ³ per 1,000,000 m ³ of air—separating them requires extremely low temperatures of approximately -200°C or lower, requiring enormous amounts of energy for low-temperature freezers.

Korean Patent Publication No. 10-2008-0025840 (published on March 24, 2008)

Meanwhile, liquefied hydrogen is transported by ships and other means, unloaded into storage tanks at receiving facilities, stored in a liquid state, vaporized, and then delivered to demand locations. Because liquefied hydrogen is stored in storage tanks at approximately -253°C, vaporizing it requires a continuous supply of heat above room temperature.

The present invention aims to provide a rare gas production system capable of supplying energy required for rare gas production by utilizing the ultra-low temperature vaporization heat discarded while vaporizing liquefied hydrogen during the process of transmitting liquefied hydrogen in a large-scale air separation unit, and a liquefied hydrogen receiving station including the same.

According to one aspect of the present invention for achieving the above-described object, a rare gas production system is provided, comprising: an air compressor for compressing air; a vaporizer for heat-exchanging compressed air from the air compressor with liquefied hydrogen to be vaporized and supplied to a demander, thereby cooling the compressed air and vaporizing the liquefied hydrogen; a separation tower for separating oxygen and nitrogen condensed in the vaporizer; a light column for condensing and separating light components from the remaining air after oxygen and nitrogen are separated from a fluid transferred from an upper discharge portion of the separation tower; and a heavy column for vaporizing and separating heavy components from the remaining air after oxygen and nitrogen are separated from a fluid transferred from a lower discharge portion of the separation tower.

Preferably, the vaporizer, separation tower, light column and heavy column are provided in a cold box, and a pretreatment device for recovering residual cold heat from the cold box and condensing and separating foreign substances contained in compressed air supplied to the vaporizer from the air compressor may be further included.

Preferably, the hard component may include neon, and the heavy component may include xenon and krypton.

Preferably, the hard column may include a primary heat exchanger that cools residual air using the cold heat of the liquefied hydrogen; and a secondary heat exchanger that further cools residual 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.

Preferably, the heavy column can vaporize heavy components by recovering waste heat of exhaust gas discharged while generating electricity using the vaporized gas of the liquefied hydrogen.

Preferably, the liquid nitrogen produced in the separation tower can be supplied as a refrigerant to maintain the liquid hydrogen in a liquid state.

Preferably, the separation tower may further include a regasifier for vaporizing liquid oxygen or nitrogen produced in the separation tower; and a turbine-generator including a turbine for expanding oxygen or nitrogen vaporized in the regasifier and a generator for generating electricity using the driving force of the turbine.

Preferably, the system may further include a liquid hydrogen storage tank for storing the liquid hydrogen; a heat medium circulation unit for circulating a heat medium to recover heat energy from at least one of the liquid hydrogen storage tank and the hard column; and a cold heat recovery device for exchanging heat with oxygen or nitrogen expanded in the turbine and cooling the heat medium.

Preferably, the system may further include a liquid hydrogen storage tank storing the liquid hydrogen; a heat medium circulation unit circulating a heat medium to recover heat energy from at least one of the liquid hydrogen storage tank and the hard column; and a fourth heat medium line supplying a heat medium for vaporizing the liquid oxygen or nitrogen from the heat medium circulation unit to the regasifier.

According to another aspect of the present invention for achieving the above-described object, a liquid hydrogen receiving station is provided, including: a plurality of liquid hydrogen storage tanks for storing liquid hydrogen and having a temperature control device for controlling an internal temperature to maintain the internal pressure at a low pressure; a liquid hydrogen demander for receiving liquid hydrogen from the liquid hydrogen storage tanks; and a plurality of pressure tanks for receiving and storing liquid hydrogen to be supplied to the liquid hydrogen demander from the liquid hydrogen storage tanks, the pressure tanks having a smaller capacity than the liquid hydrogen storage tanks but maintained at a high pressure; wherein the liquid hydrogen demander includes: a vaporizer for vaporizing the liquid hydrogen to produce gaseous hydrogen and supplying the produced gaseous hydrogen to the gaseous hydrogen demander; and the rare gas production system.

Preferably, the system may further include a second liquefied hydrogen supply line, which is a conduit through which liquefied hydrogen is transferred from the pressure tank to the vaporizer and rare gas production system.

Preferably, the temperature control device may include a heat medium circulation unit that recovers the cooling heat of the liquefied hydrogen or circulates a heat medium that supplies cooling heat to the liquefied hydrogen or the rare gas production system.

Preferably, the system may further include a compressor that compresses hydrogen vaporization gas generated in the liquefied hydrogen storage tank and supplies it to the pressure tank so that the pressure becomes a discharge pressure for supplying liquefied hydrogen from the pressure tank to a liquefied hydrogen demand source; an energy conversion unit that uses the vaporization gas compressed by the compressor as fuel to produce electricity; and a waste heat recovery line that supplies waste heat generated while producing electricity in the energy conversion unit to the heavy column.

The rare gas production system according to the present invention and the liquefied hydrogen receiving station including the same can produce rare gases such as neon, xenon, and krypton required for the semiconductor industry as well as nitrogen and oxygen by recovering the ultra-low temperature vaporization heat that is wasted while vaporizing liquefied hydrogen during the process of transmitting liquefied hydrogen and utilizing it in a large-scale air separation unit.

In addition, since the storage temperature of liquefied hydrogen is approximately -253℃, by utilizing the heat of vaporization of liquefied hydrogen as refrigeration energy for an air separation unit, almost all components contained in air can be separated and produced, except for helium, which has a lower liquefaction temperature than the storage temperature of liquefied hydrogen.

Additionally, by utilizing the heat of vaporization of liquefied hydrogen in an air separation unit, power consumption and production costs used in refrigerators, etc. can be reduced.

Additionally, liquid nitrogen, liquid oxygen, etc. produced in the air separation unit can be used as an energy source to generate electricity by supplying them to a liquid air energy storage unit.

In addition, by linking an air separation unit to a liquefied hydrogen receiving facility, the heat source required to send liquefied hydrogen and the cold heat required to separate air can be exchanged, and additional power can be produced, thereby generating additional profits and having a beneficial effect on energy and production costs and efficiency.

FIG. 1 is a schematic drawing of a liquefied hydrogen receiving station including a rare gas production system according to one embodiment of the present invention.
FIG. 2 is a schematic diagram illustrating a rare gas production system according to one embodiment of the present invention.
FIG. 3 is a schematic drawing of a liquefied air energy storage unit according to one embodiment of the present invention.

In order to fully understand the operational advantages of the present invention and the purpose achieved by the practice of the present invention, reference should be made to the attached drawings illustrating preferred embodiments of the present invention and the contents described in the attached drawings.

Hereinafter, the configuration and operation of a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. Here, when adding reference numerals to components in each drawing, it should be noted that, as much as possible, identical components are indicated with the same numerals even if they are shown in different drawings. In addition, the following embodiments may be modified in various other forms, and the scope of the present invention is not limited to the following embodiments.

Hereinafter, with reference to FIGS. 1 and 3, a rare gas production system and a liquefied hydrogen receiving station including the same according to one embodiment of the present invention will be described.

In explaining this embodiment, a liquid hydrogen receiving base means a base equipped with a number of large-capacity liquid hydrogen storage tanks on land or at sea, which receives and stores liquid hydrogen supplied from a means of transportation such as a ship, and sends the liquid hydrogen stored in the liquid hydrogen storage tanks to a place in demand for liquid hydrogen by a means of transportation such as a ship or tank truck, or directly.

First, referring to FIG. 1, a liquefied hydrogen receiving station according to one embodiment of the present invention includes a plurality of liquefied hydrogen storage tanks (102) that store liquefied hydrogen and have at least one of a temperature maintenance unit (46) and a high-density unit (45) provided therein to control the storage temperature, a liquefied hydrogen demand unit (51, 52, 53) that receives hydrogen stored in the liquefied hydrogen storage tank (102), a vaporization gas treatment unit that processes vaporization gas generated by vaporization of liquefied hydrogen, and a heat medium circulation unit (40) that recovers heat energy of the liquefied hydrogen.

In this embodiment, the vaporization gas treatment unit includes a compressor (41) that discharges vaporization gas from a liquid hydrogen storage tank (102), a buffer tank (42) that stores vaporization gas discharged from the liquid hydrogen storage tank (102), and an energy conversion unit (47) that generates electricity using vaporization gas discharged from the liquid hydrogen storage tank (101).

In addition, in the present embodiment, the liquefied hydrogen demand source (51, 52, 53) may include a vaporizer (52) that vaporizes liquefied hydrogen and supplies it to a gaseous hydrogen demand source, and a rare gas production system (53) that recovers heat energy from a liquefied hydrogen receiving base, such as cold heat of the liquefied hydrogen, cold heat and heat of the heat medium circulation unit (40), and waste heat of the energy conversion unit (47), to separate air and produce nitrogen, oxygen, and one or more rare gases. In addition, the liquefied hydrogen demand source (51, 52, 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.

In the vaporizer (52), liquefied hydrogen to be sent to the liquefied hydrogen demand source (51, 52, 53) and air for producing effective components such as oxygen in the rare gas production system (53) undergo direct or indirect heat exchange. During heat exchange in the vaporizer (52), the liquefied hydrogen is vaporized, and at least some of the specific components contained in the air are condensed, thereby allowing the condensed components to be separated from the air.

Referring to FIGS. 1 and 2, the rare gas production system (53) of the present embodiment includes an air compressor (62) that compresses air, and a pretreatment device (63) that removes impurities contained in the air compressed by the air compressor (62).

Upstream of the air compressor (62), a knockout drum (61) may be provided to separate the liquid phase contained in the air entering the air compressor (62) so that only gaseous air is introduced into the air compressor (62).

In the pretreatment device (63), impurities contained in the compressed air, such as moisture (H ₂ O) and carbon dioxide (CO ₂ ), can be removed.

The pretreatment device (63) may include a condenser (not indicated in the drawing) for condensing impurities contained in the compressed air in a gaseous state. The condenser of the pretreatment device (63) may utilize the residual cold heat of the cold box (60) described below, and may recover the residual cold heat to condense the impurities and then separate them from the compressed air.

Compressed air from which impurities have been removed in the pretreatment device (63) can be supplied to the vaporizer (52) described above to exchange heat with liquefied hydrogen. While exchanging heat with liquefied hydrogen in the vaporizer (52), some of the compressed air, particularly specific components, can be condensed.

The rare gas production system according to the present embodiment includes a separation tower (54) for producing liquid nitrogen and liquid oxygen through a fractional distillation process from compressed air cooled by heat exchange with liquefied hydrogen in a vaporizer (52), a light column (55) for separating low-gravity components from the remaining air after separating liquefied nitrogen and liquefied oxygen in the separation tower (54), and a heavy column (56) for separating high-gravity components from the remaining air after separating liquefied nitrogen and liquefied oxygen in the separation tower (54).

Liquid nitrogen and oxygen separated in the separation tower (54) are each stored in separate storage tanks (not shown). Liquid nitrogen and oxygen stored in the storage tanks can be sold to each demander.

In addition, the rare gas production system according to the present embodiment may further include a Liquefied Air Energy Storage (LAES) unit (LS) that produces electricity by using the remaining liquid nitrogen or liquid oxygen that is sold to a demand source.

Referring to FIG. 3, in this embodiment, the liquid oxygen produced in the vaporizer (52) is supplied to the liquid air energy storage unit (LS) through the liquid air line (AL) as an example, but liquid nitrogen may also be supplied to the liquid air energy storage unit (LS).

The liquefied air energy storage unit (LS) of the present embodiment includes a liquefied air storage tank (S) that stores liquid oxygen supplied from a rare gas production system, a pump (P) that discharges liquid oxygen from the liquefied air storage tank (S), a re-vaporizer (V) that vaporizes the liquefied oxygen pressurized by the pump (P), and a turbine-generator (T) that drives a turbine using the air re-vaporized in the re-vaporizer (V) as a working fluid and generates electric power with the rotational force of the turbine.

According to this embodiment, liquid nitrogen or liquid oxygen produced in a rare gas production system (53) can be supplied as a working fluid of a liquefied air energy storage unit (LS) to produce additional power.

In the re-vaporizer (V) of the present embodiment, the high-temperature heat medium can be cooled and the liquid oxygen can be vaporized through 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 also be utilized as a refrigerant for cooling the heat medium circulating in the heat medium circulation unit (40).

In addition, according to the present embodiment, a cold heat recovery device (not shown) may be further included to precool the high-temperature heat medium supplied to the heat medium circulation unit (40) by heat-exchanging the expanded regasified oxygen while driving the turbine-generator (T) and the high-temperature heat medium supplied to the heat medium circulation unit (40).

In this way, by recovering the cooling heat of the regasified oxygen, the cooling load of the heat medium circulation unit (40) can be reduced.

Referring to FIG. 2, the hard column (55) of the present embodiment is connected to the upper discharge portion of the separation tower (54) via a hard line (GL). The fluid discharged from the upper portion of the separation tower (54) is transferred to the hard column (55) via the hard line (GL).

The fluid transferred to the light column (55) through the light line (GL) is a mixture of residual nitrogen and light substances such as neon (Ne), helium (He), and methane (CH ₄ ) in a gaseous state.

The hard column (55) may be provided with a primary heat exchange unit (not shown) that primarily cools the fluid introduced into the hard column (55) through a hard line (GL) by heat exchange with liquefied hydrogen supplied from a liquefied hydrogen storage tank (102) or a pressure tank (100) described later through a second liquefied hydrogen supply line (SL2), and a secondary heat exchange unit (not shown) that secondary cools the fluid cooled primarily in the primary heat exchange unit by heat exchange with an ultra-low temperature heat medium supplied from a heat medium circulation unit (40) through a third heat medium line (ML4).

In the first heat exchange unit, the fluid can be cooled to approximately 20K by the cold heat of the liquid hydrogen transferred through the second liquid hydrogen supply line (SL2). In the second heat exchange unit, the fluid can be cooled to approximately 10K or less by the cold heat of the cryogenic heat medium transferred through the third heat medium line (ML4).

During this process, neon and methane can be condensed and separated. The separated liquid neon and methane can be stored in separate storage tanks.

The heavy column (56) is connected to the lower discharge portion of the separation tower (54) by a heavy line (HL). The fluid discharged from the lower portion of the separation tower (54) is transferred to the heavy column (56) through the heavy line (HL).

The fluid transferred to the heavy column (56) through the heavy line (HL) is a liquid mixture of residual nitrogen and heavy components such as xenon (Xe) and krypton (Kr).

In the heavy column (56), the fluid introduced into the heavy column (56) through the heavy line (HL) can be heated using the waste heat of the exhaust gas transferred from the energy conversion unit (47) through the waste heat supply line (EL). By vaporizing the residual nitrogen in a liquid state using the waste heat of the exhaust gas, liquid xenon and krypton can be obtained.

Additionally, xenon and krypton generated in the heavy column (56) are each stored in separate storage tanks and can be sold to each demander.

Since the rare gas production system (53) according to the present embodiment is installed in a liquid hydrogen receiving facility, there is no need to separately provide infrastructure that can supply products such as liquid nitrogen, oxygen, neon, xenon, and krypton produced in the rare gas production system (53) to each demander.

The pretreatment device (63), vaporizer (52), separation tower (54), light column (55) and heavy column (56) of the present embodiment can be provided in a cold box (60).

As described above, the pretreatment device (63) can utilize the residual cold heat within the cold box (60) to condense foreign substances. Accordingly, by utilizing the residual cold heat of hydrogen that has been vaporized or has had its temperature increased while cooling the fluid in the vaporizer (52) or separation tower (54), foreign substances such as moisture or carbon dioxide contained in the compressed air can be condensed and removed in the pretreatment device (63).

In this way, according to the present invention, the heat of vaporization of ultra-low temperature liquefied hydrogen discarded from a liquefied hydrogen receiving facility can be recovered to separate nitrogen and oxygen contained in the air into a liquid state and produce it.

In addition, the heat energy generated at the liquefied hydrogen acquisition base, specifically the exhaust gas waste heat of the energy conversion unit (47) and the cold heat of the ultra-low temperature heat medium cooled in the heat medium circulation unit (40), can be further recovered to obtain rare gases such as neon and xenon.

Additionally, additional power can be generated by driving a turbine using the produced liquid oxygen or nitrogen, and it can also be used as a refrigerant to cool the heat medium in the heat medium circulation section (40).

Therefore, according to the present invention, production costs can be reduced because no power is required for cooling when separating and producing various gaseous components such as nitrogen, oxygen, and neon from air.

Meanwhile, the liquid hydrogen storage tank (102) of the present embodiment is a large-capacity storage tank of 100 m ³ or more, and at least two units may be provided. The operating pressure of the liquid hydrogen storage tank (102) may be 0.1 to 6 bar, preferably 3 bar or less, more preferably 1 bar or less, or may be maintained at normal pressure.

Additionally, the liquid hydrogen storage tank (102) can be operated in either a low-temperature mode in which it is maintained at a first temperature or a high-temperature mode in which it is maintained at a second temperature that is higher than the first temperature.

In this embodiment, the first temperature is a high-densification temperature that increases the density of the stored liquefied hydrogen, and may be a temperature range in which the liquefied hydrogen exists in a mixed state of solid and liquid, i.e., about 14 to 21 K. In the low-temperature mode, at least a portion of the liquefied hydrogen stored in the liquefied hydrogen storage tank (102) may exist in a solid state having a higher density than the 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.

In this embodiment, the second temperature may be a temperature exceeding the triple point temperature of 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 higher than 21 K or at a temperature of 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 mixed state of liquid and gas.

The temperature maintenance unit (46) and the densification unit (45) of the liquid hydrogen storage tank (102) are connected to the heat medium circulation unit (40) by the first heat medium line (ML2). The cryogenic heat medium cooled in the heat medium circulation unit (40) is transferred to the temperature maintenance unit (46) and the densification unit (45) along the first heat medium line (ML2), and the heat medium, whose temperature has increased while cooling the liquid hydrogen in the temperature maintenance unit (46) and the densification unit (45), may be returned to the heat medium circulation unit (40) along the first heat medium line (ML2), or may be returned to the heat medium circulation unit (40) in a state where its temperature has been lowered while heating the fluid in the heavy column (56).

The heat medium circulation 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 cold heat to the hydrogen stored in the liquefied hydrogen storage tank (102), and then receives a high temperature heat medium.

In addition, the heat medium circulation unit (40) supplies high-temperature heat medium to the liquefied hydrogen storage tank (102) when the liquefied hydrogen storage tank (102) is operated in high-temperature mode, and recovers the cold heat of the hydrogen stored in the liquefied hydrogen storage tank (102) to supply an ultra-low-temperature heat medium.

In this embodiment, the heat medium circulating in the heat medium circulation unit (40) may be helium or another medium that indirectly transfers heat energy between helium and the liquefied hydrogen stored in the liquefied hydrogen storage tank (102).

In this embodiment, the low-temperature mode can be used for the purpose of suppressing the reactivity of 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 stabilizing the liquefied hydrogen by preventing the phase change into gas and the diffusion of vaporization.

The liquefied hydrogen stored in the liquefied hydrogen storage tank (102) by the densification unit (45) may partially exist in a slurry state. By partially solidifying the stored liquefied hydrogen rather than all of it, the hydrogen is stored in a solid state that partially retains more cold heat, thereby maximizing the latent heat and stably storing the hydrogen.

In addition, since some of the liquid hydrogen exists in a solid state, it acts as a shield to suppress vaporization of the liquid hydrogen, and through this operation, the internal pressure of the liquid hydrogen storage tank (102) can be maintained at 1 bar or less.

The high-temperature mode may be implemented for the purpose of supplying fuel for generating electricity in the energy conversion unit (47) by vaporizing a portion of the liquefied hydrogen stored in the liquefied hydrogen storage tank (102) to induce the generation of a certain amount of evaporated gas. In addition, cold heat to be supplied to the liquefied hydrogen storage tank (102) operated in the low-temperature mode or the rare gas production system (53) may be recovered from the liquefied hydrogen in the liquefied hydrogen storage tank (102) operated in the high-temperature mode using a heat medium.

In the high temperature mode of this embodiment, when a high temperature heat medium is supplied to the temperature maintenance unit (46), a vaporization reaction begins to occur. When gaseous nitrogen or methane is compressed and then expanded by Joule-Thomson, the temperature decreases and liquefaction occurs. However, gaseous hydrogen or helium have a lower inversion temperature than room temperature, so when expanded by Joule-Thomson at room temperature, the temperature actually increases. Therefore, hydrogen must be expanded below its inversion temperature to lower its temperature.

In this embodiment, the internal temperature of the liquid hydrogen storage tank (102) operated in high-temperature mode is maintained at a temperature higher than 20K but lower than the inversion temperature, and a vacuum is applied inside the liquid hydrogen storage tank (102) to promote conversion to para-hydrogen, while simultaneously supplying and exhausting the evaporated gas to control the pressure of the liquid hydrogen storage tank (102) and the amount of evaporated gas generated. By this operation, the internal pressure of the liquid hydrogen storage tank (102) can be maintained at 3 bar or less.

Hydrogen has the characteristic of evaporating liquid hydrogen due to the heat of conversion generated during the ortho-para conversion reaction, which is greater than the latent heat of vaporization of liquid hydrogen. Due to this characteristic, hydrogen vapor gas is generated irregularly, with a chain reaction occurring momentarily and then the amount generated rapidly decreasing when the reaction stops.

According to this embodiment, the amount of evaporated gas generated can be controlled to a constant level by operating the liquid hydrogen storage tank (102) in high temperature mode and low temperature mode.

In the liquefied hydrogen receiving station according to the present embodiment, hydrogen vaporization gas (or vaporized gas) can be utilized as fuel for generating electricity to be used within the system. Among the multiple liquefied hydrogen storage tanks (102), at least one liquefied hydrogen storage tank (102) operates in a high-temperature mode to continuously generate a constant amount of hydrogen vaporization gas and supply the vaporization gas to the energy conversion unit (47), thereby stably producing and supplying electricity.

Meanwhile, in this embodiment, when it is time to discharge the evaporation gas in the liquefied hydrogen storage tank (102), the compressor (41) is operated to discharge the evaporation gas. The liquefied hydrogen storage tank (102) and the compressor (41) are connected by a evaporation gas supply line (BL2), and the evaporation gas generated in the liquefied hydrogen storage tank (102) can be discharged through the evaporation gas supply line (BL2) and introduced into the compressor (41).

Meanwhile, the compressor (41) of the present embodiment can operate to exhaust the vaporized gas from the liquid hydrogen storage tank (102) to create a medium vacuum state when the vaporized gas inside the liquid hydrogen storage tank (102) is explosively generated.

When the compressor (41) is operated and the liquid hydrogen storage tank (102) is in a medium vacuum state, an ortho-para conversion reaction occurs in the liquid hydrogen storage tank (102), and when the proportion of para hydrogen increases, the operation of the compressor (41) is stopped to release the vacuum in the liquid hydrogen storage tank (102), thereby stabilizing the liquid hydrogen storage tank (102).

The vaporized gas discharged from the liquefied hydrogen storage tank (102) may be transferred to the buffer tank (42) through the first vaporized gas distribution line (CL1) and stored in the buffer tank (42), or may be transferred to the energy conversion unit (47) through the second vaporized gas distribution line (CL2).

In this embodiment, the energy conversion unit (47) may include at least one of a fuel cell that produces electricity through an electrochemical reaction using hydrogen as fuel, and a turbine generator that produces electricity by driving a turbine using hydrogen as a working fluid and converting the driving energy of the turbine into electricity.

The power generated in the energy conversion unit (47) of this embodiment can be used in the heat medium circulation unit (40) and the rare gas production system (53), and can be distributed and supplied to the power demand point on board by a power distribution means (not shown) such as a switch board (not shown).

In addition, according to the present embodiment, it may further include two or more pressure tanks (100) that are operated at high pressure and have a smaller capacity than the liquefied hydrogen storage tank (102) and store liquefied hydrogen to be supplied to liquefied hydrogen demanders (51, 52, 53), liquefied hydrogen supply lines (SL1, SL2) that connect the pressure tanks (100) and the liquefied hydrogen demanders (51, 52, 53) and transport liquefied hydrogen from the pressure tanks (100) to the liquefied hydrogen demanders (51, 52, 53), and recovery lines (RL1, RL2, RL3, RL4, RL5) that recover evaporated gas from the pressure tanks (100) and the liquefied hydrogen demanders (51, 52, 53).

The operating pressure of the pressure tank (100) of the present embodiment can be maintained at a higher pressure than the operating pressure of the liquefied hydrogen storage tank (102) operated at 3 bar or less. For example, the pressure tank (100) of the present embodiment can be operated at 6 bar or more, 8 bar or more, or 10 bar or more.

Meanwhile, since the operating pressure of the pressure tank (100) is higher than the operating pressure of the liquid hydrogen storage tank (102), a supply pump (50) may be provided in the liquid hydrogen discharge line (LL) connecting the liquid hydrogen storage tank (102) and the pressure tank (100) to supply liquid hydrogen from the liquid hydrogen storage tank (102) to the pressure tank (100) at a higher pressure. At this time, the liquid hydrogen is pressurized by the supply pump (50) and transferred to the pressure tank (100).

The pressure tank (100) of the present embodiment can be placed at a position lower than the height of the liquid hydrogen storage tank (102). Therefore, the supply pump (50) can be omitted as an optional configuration, and even without providing additional power such as the supply pump (50), the liquid hydrogen can be transferred from the liquid hydrogen storage tank (102) to the pressure tank (100) by the height difference.

According to the present embodiment, before transferring liquefied hydrogen from the storage tank (102) to the pressure tank (100), precooling can be performed 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 a supply pump (50) is arranged, cavitation of the supply pump (50) can be prevented by precooling the liquefied hydrogen discharge line (LL) and the supply pump (50) together.

As a means for precooling 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) come into contact, i.e., upstream of the header, and joins the portion where the liquefied hydrogen storage tank (102) and the liquefied hydrogen discharge line (LL) come into contact, i.e., downstream of the header, to recirculate the liquefied hydrogen, the temperature of which has increased while precooling the liquefied hydrogen discharge line (LL), to the upstream of the liquefied hydrogen discharge line (LL).

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 source (51, 52, 53) can be maintained at a pressure lower than 8 bar or 10 bar, preferably 3 bar or less.

The internal pressure of the pressure tank (100) can be maintained by compressing the vaporization gas discharged from the liquid hydrogen storage tank (102) and supplying it to the pressure tank (100). In order to prevent the pressure of the pressure tank (100) from falling below the operating pressure, the high-pressure vaporization gas stored in the buffer tank (42) can be supplied to the pressure tank (100) with priority over the energy conversion unit (47).

Supply of liquefied hydrogen from the pressure tank (100) to the liquefied hydrogen demand source (51, 52, 53) can be achieved by the liquefied hydrogen being transferred from the liquefied hydrogen storage tank (102) to the pressure tank (100) along the liquefied hydrogen discharge line (LL) or by the self-pressure of the high-pressure evaporation gas transferred from the buffer tank (42) through the third evaporation gas distribution line (CL3), thereby sending the liquefied hydrogen from the pressure tank (100) to the first liquefied gas supply line (SL1) and the second liquefied gas supply line (SL2).

The third evaporation gas distribution line (CL3) is a high-pressure evaporation gas path connecting 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 evaporation gas compressed in the compressor (41) or the high-pressure evaporation gas compressed in the compressor (41) and then stored in the buffer tank (42) is transferred to the pressure tank (100) through the third evaporation gas distribution line (CL3).

In this embodiment, when the high-pressure vaporization gas delivered through the third vaporization 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).

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 unit (40) and a fifth recovery line (RL5) connecting the pressure tank (100) and the upstream of the compressor (41) may be further included.

High temperature heat medium is transferred from the heat medium circulation unit (40) to the pressure tank (100) through the second heat medium line (ML3), and low temperature heat medium, which has recovered cold heat while vaporizing liquefied hydrogen stored in the pressure tank (100), is returned to the heat medium circulation unit (40) through the second heat medium line (ML3).

When the heat medium circulates 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.

In addition, after discharging the evaporation gas through the fifth recovery line (RL5), the evaporation gas is supplied to the upstream of the compressor (41), and the evaporation gas is compressed in the compressor (41) and supplied to the pressure tank (100) in the state of high-pressure evaporation gas, thereby maintaining the operating pressure of the pressure tank (100).

The second heat medium line (ML3) connecting the pressure tank (100) and the heat medium circulation unit (40), the header at which the second heat medium line (ML3) is connected to the pressure tank (100) and the heat medium circulation unit (40), and various devices such as a heat exchanger and valve that can be installed in the second heat medium line (ML3) can be installed in a cold box and vacuum-insulated in the first stage.

The cold box can be equipped with a hydrogen detection device to detect hydrogen leaks. Additionally, insulation can be installed on the outside of the cold box to provide additional insulation.

The liquid hydrogen storage facility (51) of the present embodiment can be supplied with liquid hydrogen through a first liquid hydrogen supply line (SL1) connecting the pressure tank (100) and the liquid hydrogen storage facility (51), and the vaporizer (52) and the rare gas production system (53) can be supplied with liquid hydrogen through a second liquid hydrogen supply line (SL2) connecting the pressure tank (100), the vaporizer (52), and the rare gas production system (53).

Meanwhile, before transporting liquefied hydrogen to a liquefied hydrogen demand source (51, 52, 53), the liquefied hydrogen supply line (SL1, SL2) can be precooled using liquefied gas stored in a pressure tank (100) or a liquefied hydrogen storage tank (102).

The vaporized evaporated gas that is precooled through the liquefied hydrogen supply line (SL1, SL2) can be recovered to the pressure tank (100) through the third recovery line (RL3) connected to the pressure tank (100) or recovered to the compressor (41) through the fourth recovery line (RL4) connected to the compressor (41).

The vaporized evaporation gas while precooling the first liquefied hydrogen supply line (SL1) is recovered to the third recovery line (RL3) and the fourth recovery line (RL4) through the first recovery line (RL1), and the vaporized evaporation gas while precooling the second liquefied hydrogen supply line (SL2) is recovered to the third recovery line (RL3) and the fourth recovery line (RL4) through the second recovery line (RL2).

Meanwhile, while supplying liquefied hydrogen to liquefied gas demand sites (51, 52, 53), the evaporated gas generated at the liquefied hydrogen demand site (51, 52) and exceeding the allowable pressure of the liquefied hydrogen demand site (51, 52) can also be recovered to the compressor (41) through the first to fourth recovery lines (RL1 to RL4).

The evaporated gas recovered upstream of the compressor (41) through the fourth recovery line (RL4) and the fifth recovery line (RL5) can be compressed by the compressor (41) and then stored in the buffer tank (42) or recovered in the pressure tank (100) and used to maintain the internal pressure of the pressure tank (100).

In addition, the evaporation gas recovered from the liquefied hydrogen demand source (51, 52, 53) through the fourth recovery line (RL4) and the fifth recovery line (RL5) can be supplied to the energy conversion unit (47) through the second evaporation gas distribution line (CL2) connected to the energy conversion unit (47) and utilized for power generation.

Meanwhile, the heat of vaporization generated when liquefied hydrogen is vaporized in the vaporizer (52) can be recovered through the rare gas production system (53).

In addition, waste heat generated while producing electricity in the energy conversion unit (47) can be supplied through a waste heat supply line (EL) connecting the energy conversion unit (47) and the rare gas production system (53) and utilized as heat energy required for separating air. The temperature of the heat energy transferred through the waste heat supply line (EL) can be approximately 500 to 600°C.

The liquefied hydrogen receiving station according to this embodiment can use the evaporated gas generated in the process of unloading liquefied hydrogen to maintain the pressure of the pressure tank (100) to generate a transmission pressure to a liquefied hydrogen demand source (51, 52, 53), and can use it as fuel to generate electricity in the energy conversion unit (47).

In addition, during the process of unloading liquefied hydrogen, the pressure of the pressure tank (100) can be maintained while effectively maximizing the use of the cold heat and waste heat of the liquefied hydrogen.

In addition, according to the present embodiment, while supplying liquid hydrogen to a liquid hydrogen demander from one of two or more pressure tanks (100), liquid hydrogen can be charged into another pressure tank (100).

It is obvious to a person skilled in the art that the present invention is not limited to the above embodiments, and that various modifications or changes can be made without departing from the technical spirit of the present invention.

100: Pressure tank 102: Liquid hydrogen storage tank
40: Heat medium circulation section 41: Compressor
42: Buffer tank 45: Densification section
46: Temperature maintenance unit 47: Energy conversion unit
50: Supply pump 51: Liquid hydrogen storage facility
52: Carburetor 53: Rare gas production system
54: Separation tower 55: Rigid column
56: Heavy column 60: Cold box
61: Knockout drum 62: Pretreatment device
BL2: Evaporation gas supply line LL: Liquefied hydrogen discharge line
CL1, CL2, CL3: Evaporation gas distribution line LL1: Liquefied hydrogen recovery line
ML2, ML3, ML4, ML5: Heat medium circulation line EL: Waste heat supply line
RL1, RL2, RL3, RL4, RL5: Recovery line GL: Hard line
SL1, SL2: Liquid hydrogen supply line HL: Heavy line
LS: Liquefied Air Energy Storage Unit AL: Air Line
S: Liquefied air storage tank P: Pump
V: Re-vaporizer T: Turbine-generator

Claims (13)

An air compressor that compresses air;
A vaporizer that cools the compressed air and vaporizes the liquid hydrogen by exchanging heat between the compressed air from the above air compressor and the liquid hydrogen to be vaporized and supplied to the demander;
A separation tower for separating oxygen and nitrogen condensed in the above vaporizer;
A light column that separates oxygen and nitrogen from the fluid transferred from the upper discharge portion of the above separation tower and condenses and separates light components from the remaining residual air; and
A rare gas production system, comprising a heavy column for separating oxygen and nitrogen from the fluid transferred from the lower discharge portion of the above separation tower and vaporizing and separating heavy components from the remaining air. In claim 1,
The above vaporizer, separation tower, light column and heavy column are installed in a cold box,
A rare gas production system further comprising a pretreatment device that recovers residual cold heat from the cold box and condenses and separates foreign substances contained in compressed air supplied to the vaporizer from the air compressor. In claim 1,
The above hard component contains neon,
The above heavy components are a rare gas production system including xenon and krypton. In claim 1,
The above rigid column is,
A primary heat exchanger that cools the residual air using the cold heat of the above liquefied hydrogen; and
A rare gas production system comprising a secondary heat exchanger that further cools the remaining air cooled in the primary heat exchanger by using a heat medium that recovers the cold heat of the liquefied hydrogen while vaporizing the liquefied hydrogen. In claim 1,
The above heavy column is,
A rare gas production system that generates electricity using the vaporized gas of the above-mentioned liquefied hydrogen and recovers waste heat from the exhaust gas emitted to vaporize heavy components. In claim 1,
A rare gas production system that supplies liquid nitrogen produced in the above separation tower as a refrigerant to maintain the liquid hydrogen in a liquid state. In claim 1,
A regasifier that vaporizes liquid oxygen or nitrogen produced in the above separation tower; and
A rare gas production system further comprising a turbine-generator including a turbine that expands oxygen or nitrogen vaporized in the regasifier, and a generator that produces electricity using the driving force of the turbine. In claim 7,
A liquid hydrogen storage tank for storing the above liquid hydrogen;
A heat medium circulation unit that circulates the heat medium to recover heat energy from at least one of the liquefied hydrogen storage tank and the light column; and
A rare gas production system further comprising a cold heat recovery device that cools the heat medium by exchanging heat between the oxygen or nitrogen expanded in the turbine and the heat medium. In claim 7,
A liquid hydrogen storage tank for storing the above liquid hydrogen;
A heat medium circulation unit that circulates the heat medium to recover heat energy from at least one of the liquefied hydrogen storage tank and the light column; and
A rare gas production system further comprising a fourth heat medium line for supplying a heat medium for vaporizing liquid oxygen or nitrogen from the heat medium circulation section to the regasifier. A plurality of liquid hydrogen storage tanks having a temperature control device for controlling the internal temperature to store liquid hydrogen and maintain the internal pressure at a low level;
A liquid hydrogen demand source that receives liquid hydrogen from the liquid hydrogen storage tank; and
A plurality of pressure tanks are provided to receive and store liquid hydrogen to be supplied to the liquid hydrogen demand source from the liquid hydrogen storage tank, and are maintained at a high pressure while having a smaller capacity than the liquid hydrogen storage tank;
The above liquid hydrogen demand source is,
A vaporizer that vaporizes the above liquefied hydrogen to produce gaseous hydrogen and supplies it to a gaseous hydrogen demand source; and
A liquefied hydrogen receiving station comprising a rare gas production system as described in any one of claims 1 to 9. In claim 10,
A liquefied hydrogen receiving station further comprising a second liquefied hydrogen supply line through which liquefied hydrogen is transferred from the pressure tank to the vaporizer and rare gas production system. In claim 10,
A liquefied hydrogen receiving station, comprising a heat medium circulation unit that recovers the cold heat of the liquefied hydrogen from the temperature control device or circulates a heat medium that supplies cold heat to the liquefied hydrogen or the rare gas production system. In claim 10,
A compressor that compresses hydrogen evaporation gas generated in the above liquid hydrogen storage tank and supplies it to the pressure tank so that the pressure becomes a delivery pressure for supplying liquid hydrogen to a liquid hydrogen demand source from the pressure tank;
An energy conversion unit that produces electricity by using the evaporated gas compressed by the compressor as fuel; and
A liquefied hydrogen receiving station further comprising a waste heat recovery line that supplies waste heat generated while generating electricity in the energy conversion unit to the heavy column.