KR102595622B1 - Hydrogen storage system for liquid hydrogen vaporization storage - Google Patents

Abstract

One embodiment of the present invention can provide a hydrogen storage system for storing liquefied hydrogen vaporized gas. The hydrogen storage system for storing liquefied hydrogen vaporized gas includes a storage tank unit including a liquefied hydrogen storage tank for storing liquefied hydrogen; and a storage tank unit installed outside the storage tank unit and receiving naturally vaporized hydrogen gas from the liquefied hydrogen storage tank. It may include a hydrogen storage unit containing an absorbing hydrogen storage alloy.

Description

{HYDROGEN STORAGE SYSTEM FOR LIQUID HYDROGEN VAPORIZATION STORAGE}

The present invention relates to a hydrogen storage system for storing liquefied hydrogen vaporized gas. More specifically, it relates to a hydrogen storage system that can store liquefied hydrogen vaporization gas using a hydrogen storage alloy.

Recently, as the need to utilize hydrogen has emerged to solve environmental problems and replace fossil fuels, research on hydrogen fuel is actively underway. However, because hydrogen exists as a gas at room temperature and atmospheric pressure, it has a low energy density per volume and is not only inconvenient to transport and store, but also has poor safety.

These hydrogen storage methods include a method of storing hydrogen gas by compressing it, a method of storing it by liquefying it, or a method using an alloy for hydrogen storage.

In addition, liquefied hydrogen must be cooled to a cryogenic temperature of -253 degrees Celsius, so energy consumption is extreme, and when a liquefied hydrogen tank is stored at room temperature, a significant amount may naturally vaporize and evaporate.

The amount of hydrogen gas (BOG: Boil off gas) naturally vaporized in the liquefied hydrogen tank may be 1% to 4% of the total. When storing 1 ton of hydrogen, 10 to 40 kg of hydrogen can be vaporized per day.

At this time, hydrogen gas (BOG: Boil off gas) naturally vaporized within the liquefied hydrogen tank can increase the pressure inside the liquefied hydrogen tank. If the pressure inside the liquefied hydrogen tank increases, the risk of hydrogen explosion may increase.

Accordingly, hydrogen gas naturally vaporized inside the liquefied hydrogen tank can be released into the atmosphere, but if the entire amount of naturally vaporized gas is released into the atmosphere, there is an economic loss due to waste of hydrogen gas, and the method of re-liquefaction requires additional equipment. There is a problem of low economic feasibility due to the demand.

Therefore, research is needed on a hydrogen storage system or hydrogen storage alloy that consumes less energy, is safe, and can store the hydrogen gas naturally vaporized and discharged from the liquefied hydrogen tank for a long period of time.

Republic of Korea Patent No. 2020-0009221

The technical problem to be achieved by the present invention is to provide a hydrogen storage system that can safely store hydrogen gas naturally vaporized and discharged from a liquefied hydrogen storage tank with low energy consumption.

In addition, the present invention provides a hydrogen storage alloy that is included in the hydrogen storage system and can store hydrogen gas naturally vaporized and discharged from the liquefied hydrogen storage tank.

The technical problem to be achieved by the present invention is not limited to the technical problem mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description below. There will be.

In order to achieve the above technical problem, an embodiment of the present invention provides a hydrogen storage system for storing liquefied hydrogen vaporized gas.

In one embodiment of the present invention, the hydrogen storage system for storing liquefied hydrogen vaporized gas is a storage tank unit including a liquefied hydrogen storage tank for storing liquefied hydrogen; and is installed outside the storage tank unit and includes the liquefied hydrogen storage tank. It may include a hydrogen storage unit including a hydrogen storage alloy that receives and absorbs naturally vaporized hydrogen gas.

In one embodiment of the present invention, a valve is located between the storage tank and the hydrogen storage unit to control the discharge of the naturally vaporized hydrogen gas when the naturally vaporized hydrogen gas is discharged from the inside of the liquefied hydrogen storage tank. More may be included.

In one embodiment of the present invention, the process of receiving and absorbing hydrogen gas in the hydrogen storage alloy may be performed at a temperature of -100°C to 30°C.

In one embodiment of the present invention, the hydrogen storage alloy may have a plateau pressure lower than the discharge pressure of naturally vaporized hydrogen gas (BOG) inside the liquefied hydrogen storage tank.

In one embodiment of the present invention, the hydrogen storage alloy may have a plateauing pressure of 5 bar or less at 30°C.

In one embodiment of the present invention, hydrogen absorbed by the hydrogen storage alloy may be released from the hydrogen storage alloy through heat treatment.

In one embodiment of the present invention, the hydrogen storage alloy may have a negative enthalpy greater than -35 kJ/mole based on the enthalpy of reaction with hydrogen.

In order to achieve the above technical problem, another embodiment of the present invention provides a method for controlling a hydrogen storage system for storing liquefied hydrogen vaporized gas.

In an embodiment of the present invention, the method of controlling the hydrogen storage system for storing the liquefied hydrogen vaporized gas is such that hydrogen gas naturally vaporized inside the liquefied hydrogen storage tank moves to the hydrogen storage unit and is absorbed into the hydrogen storage alloy. A hydrogen gas absorption measurement step of measuring the absorption amount of; and

A control step of controlling the discharge of naturally vaporized hydrogen gas from the liquefied hydrogen storage tank by closing the valve when the absorption amount of hydrogen gas absorbed into the hydrogen storage alloy exceeds the preset reference amount compared to the preset reference amount. can do.

In one embodiment of the present invention, the control step may further include a step of releasing hydrogen from the hydrogen storage alloy when the hydrogen storage alloy in which the hydrogen gas has been absorbed is heat treated.

In one embodiment of the present invention, the hydrogen storage alloy may have a plateauing pressure of 5 bar or less at 30°C.

The hydrogen storage system for storing liquefied hydrogen vaporized gas according to an embodiment of the present invention consumes little energy and can safely store hydrogen gas naturally vaporized and discharged from a liquefied hydrogen storage tank.

In addition, the hydrogen storage alloy included in the hydrogen storage system for storing liquefied hydrogen vaporized gas has a lower plateau pressure than the pressure of naturally vaporized hydrogen gas released at low pressure, so naturally vaporized hydrogen gas (BOG) can be directly released without any separate manipulation. It has an absorbing effect.

The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

Figure 1 is a conceptual diagram showing the approximate configuration of a hydrogen storage system for storing liquefied hydrogen vaporized gas according to an embodiment of the present invention.
Figure 2 is a conceptual diagram schematically showing the gas flow of a hydrogen storage system for storing liquefied hydrogen vaporized gas according to an embodiment of the present invention.
Figure 3 is a PCT diagram of a hydrogen storage alloy for storing liquefied hydrogen vaporized gas according to an embodiment of the present invention.
Figure 4 is a graph showing the hydrogen release pressure according to the DFT calculation formula and the DFT calculation results based on 50°C.

Hereinafter, the present invention will be described with reference to the attached drawings. However, the present invention may be implemented in various different forms and, therefore, is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts that are not related to the description are omitted, and similar parts are given similar reference numerals throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, combined)" with another part, this means not only "directly connected" but also "indirectly connected" with another member in between. "Includes cases where it is. Additionally, when a part is said to “include” a certain component, this does not mean that other components are excluded, but that other components can be added, unless specifically stated to the contrary.

The terms used herein are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “comprise” or “have” are intended to indicate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Referring to FIG. 1, a hydrogen storage system for storing liquefied hydrogen vaporized gas according to an embodiment of the present invention will be described.

Figure 1 is a conceptual diagram showing the approximate configuration of a hydrogen storage system for storing liquefied hydrogen vaporized gas according to an embodiment of the present invention.

The hydrogen storage system for storing liquefied hydrogen vaporized gas includes a storage tank unit (10) including a liquefied hydrogen storage tank for storing liquefied hydrogen; and a hydrogen storage unit 20 installed outside the storage tank unit and including a hydrogen storage alloy that receives and absorbs naturally vaporized hydrogen gas from the liquefied hydrogen storage tank.

In addition, a valve 30 is located between the storage tank 10 and the hydrogen storage unit 20 and controls the discharge of the naturally vaporized hydrogen gas when the naturally vaporized hydrogen gas is discharged from the inside of the liquefied hydrogen storage tank. ) may further be included.

The storage tank unit 10 of the hydrogen storage system for storing liquefied hydrogen vaporized gas according to an embodiment of the present invention may include a liquefied hydrogen storage tank.

Since the liquefied hydrogen must be cooled to a cryogenic temperature of -253 degrees Celsius, energy consumption is extreme, and when the liquefied hydrogen tank is stored at room temperature, a significant amount may naturally vaporize and evaporate.

The amount of hydrogen gas (BOG: Boil off gas) naturally vaporized in the liquefied hydrogen tank may be 1% to 4% of the total. When storing 1 ton of hydrogen, 10kg to 40kg of hydrogen can be vaporized per day.

At this time, hydrogen gas (BOG: Boil off gas) naturally vaporized within the liquefied hydrogen tank can increase the pressure inside the liquefied hydrogen tank. If the pressure inside the liquefied hydrogen tank increases, the risk of hydrogen explosion may increase.

Therefore, a system that can collect naturally vaporized hydrogen gas within the liquefied hydrogen tank is needed.

Accordingly, the hydrogen storage system for storing liquefied hydrogen vaporized gas of the present invention may include a hydrogen storage unit 20.

The hydrogen storage unit 20 is installed outside the storage tank unit and may include a hydrogen storage alloy that receives and absorbs naturally vaporized hydrogen gas from the liquefied hydrogen storage tank.

At this time, the process of receiving and absorbing hydrogen gas in the hydrogen storage alloy 40 according to an embodiment of the present invention may be performed at a temperature of -100°C to 30°C. The reason why the process of receiving and absorbing hydrogen gas in the hydrogen storage alloy 40 according to an embodiment of the present invention is performed at a temperature of -100°C to 30°C is as follows.

In fact, liquefied hydrogen can be vaporized at -253 degrees Celsius, so hydrogen gas can be supplied to the hydrogen storage tank even at cryogenic temperatures exceeding -253 degrees Celsius and hydrogen gas can be absorbed into the hydrogen storage alloy.

At this time, the temperature may slightly increase while hydrogen gas is supplied into the hydrogen storage tank, and the process of incorporating hydrogen into the hydrogen storage alloy may be accompanied by an exothermic reaction.

Therefore, the hydrogen storage system for storing liquefied hydrogen according to an embodiment of the present invention can be performed at -100°C to 30°C.

In addition, the hydrogen storage alloy 40 according to an embodiment of the present invention may have a plateau pressure lower than the discharge pressure of naturally vaporized hydrogen gas (BOG) inside the liquefied hydrogen storage tank.

The pressure inside the liquefied hydrogen storage tank is maintained at 2 to 5 bar pressure, and when the hydrogen is vaporized and a certain pressure or higher (eg, 5 atmospheres) is formed, hydrogen gas can be discharged through the valve 30.

At this time, the hydrogen storage alloy 40 has a plateauing pressure, and the plateauing pressure of the hydrogen storage alloy 40 may be determined by its reactivity with hydrogen.

Even if the hydrogen concentration in the hydrogen storage alloy 40 increases, the region where the equilibrium hydrogen pressure does not change and remains constant is called a plateau region, and the equilibrium hydrogen pressure at this time is called plateau pressure.

The plateau pressure is an important characteristic when storing or releasing hydrogen in an alloy and determines the hydrogen pressure when storing hydrogen and the hydrogen pressure when releasing hydrogen. Additionally, the plateau pressure in the hydrogen storage alloy 40 can be adjusted depending on the purpose for which the hydrogen storage alloy is used.

The hydrogen storage alloy 40 according to an embodiment of the present invention can control the plateau pressure according to the alloy composition system, and the plateau pressure of the hydrogen storage alloy 40 may be an alloy lower than the pressure of the gas that is vaporized and released. , when the hydrogen storage alloy 40 is used, vaporized gas can be absorbed as is.

The plateauing pressure of the hydrogen storage alloy 40 according to an embodiment of the present invention may be 5 bar or less. The reason why the plateauing pressure of the hydrogen storage alloy 40 is 5 bar or less will be explained.

In the case of the hydrogen storage system for storing liquefied hydrogen vaporized gas, the pressure of the liquefied hydrogen vaporized gas exhaust gas is 5 bar based on 30°C, and the flat pressure of the hydrogen storage alloy is 5 bar or less, which is lower than the pressure of the liquefied hydrogen vaporized gas discharge gas. All of the hydrogen that is vaporized and released can be stored inside the hydrogen storage alloy.

At this time, the plateau pressure of the AB-based hydrogen storage alloy according to an embodiment of the present invention is related to reactivity with hydrogen, and the reactivity with hydrogen can be determined by hydride forming enthalpy (enthalpy of reaction with hydrogen).

That is, when the plateau pressure of the hydrogen storage alloy is 5 bar or less at 30°C, the hydride forming enthalpy (enthalpy of reaction with hydrogen) may have a negative enthalpy greater than -35 kJ/mole.

At this time, based on the hydride forming enthalpy (enthalpy of reaction with hydrogen), the AB alloy having a negative enthalpy greater than -35 kJ/mole can be derived from first principles and DFT (density function theory) calculation results. there is.

Referring to FIG. 4, the reason why the hydride forming enthalpy (enthalpy of reaction with hydrogen) of the hydrogen storage alloy according to the density function theory (DFT) calculation results has a negative enthalpy greater than -35 kJ/mole will be explained.

Figure 4 is a graph showing the hydrogen release pressure according to the DFT calculation formula and the DFT calculation results based on 50°C.

Since the plateau pressure of the hydrogen storage alloy increases as the temperature increases, it must be heated when releasing hydrogen and cooled to absorb hydrogen when storing hydrogen. As shown in Figure 4, based on 50°C. When the discharge pressure is 1 atm or less than 1 atm, the absorption plateau pressure at 30°C is further lowered, indicating that hydrogen can be absorbed well.

At this time, referring to the calculation formula included in the graph of FIG. 4, when the discharge pressure is 1 atm based on 50°C, if the enthalpy of reaction with hydrogen is a negative value larger than the value derived from the calculation formula, the plateau pressure is even lower. Therefore, according to the above calculation formula, if the enthalpy of reaction with hydrogen has a negative value greater than -35 kJ/mole, the plateau pressure may be 5 atmospheres or less.

Therefore, based on the hydride forming enthalpy (enthalpy of reaction with hydrogen) according to an embodiment of the present invention, the AB-based alloy having a negative enthalpy greater than -35 kJ/mole has a plateauing pressure of 5 bar (5 atmospheres). It may be below 5 bar and can well absorb the liquefied hydrogen vaporization gas released below 5 bar.

A hydrogen storage alloy applicable according to an embodiment of the present invention will be described.

The hydrogen storage alloy according to an embodiment of the present invention can be applied to the AB-based, AB _2- based, and AB ₅ -based hydrogen storage alloys.

Metal A forms a stable hydride because it shows high chemical affinity with hydrogen, while metal B is a component that lowers the stability of the hydride and enables a reversible reaction.

If metal A is excessive, it holds hydrogen too strongly, making it difficult to release hydrogen, and if metal B is excessive, hydrogen may not be absorbed well, so there is a need to manufacture a hydrogen storage alloy at an appropriate ratio.

The AB-based hydrogen storage alloy has a hydrogen storage capacity of 1,1 wt% to 2.0 wt% and is difficult to absorb and activate hydrogen, and the AB _2- based hydrogen storage alloy has a hydrogen storage capacity of 1,7 wt% to 2.0 wt%. Likewise, it may have the characteristic of being difficult to activate by absorbing hydrogen.

In addition, the AB ₅ -based hydrogen storage alloy has a hydrogen storage capacity of 1.2 wt% to 1.6 wt%, and the BCC-based hydrogen storage alloy has a hydrogen storage capacity of 1.6 wt% to 2.0 wt% and is characterized by a slow reaction rate.

For example, in an AB-based hydrogen storage alloy, A may include Ti (titanium), Zr (zirconium), or V (vanadium), and B may include Fe (iron).

As a specific example, the AB-based alloy may be a TiFe alloy.

For example, when part of Ti is replaced with Zr, hydrogen absorption ability can be improved and cycle performance can be improved.

For example, when part of Ti is replaced with V, activation characteristics may be improved.

For example, types of the AB ₂ -based hydrogen storage alloy may include Zn(Mn) ₂ , Ti(Mn) _{2, and} Zn(V) ₂ , and the AB _5- based hydrogen storage alloy may include LaNi _{5 and} MnNi ₅ . There may be etc.

Additionally, the BCC-based hydrogen storage alloy may include Ti-V-Cr, Ti-V-Mn, etc.

At this time, the hydrogen storage alloy 40 according to an embodiment of the present invention may be composed of AB-based, AB _2- based, AB ₅ -based, or BCC-based alloy.

At this time, the hydrogen storage alloy 40 according to an embodiment of the present invention may be a hydrogen storage alloy with a plateau pressure of 4 bar or less based on the above 30°C, and may be an AB-based alloy, such as TiFe-based alloy, or an AB _2- based alloy, such as TiMn _{2 .} It may be composed of one type selected from AB _5- based alloy, LaNi _5- based alloy, and TiVCr-based alloy as BCC-based alloy.

The hydrogen storage alloy according to another embodiment of the present invention has a chemical formula in which the overall composition is expressed as TiFe _1-x M _x , where M is one or more selected from V, Cr, Mn, Co, Ni, Cu, and Al. It is characterized in that x is greater than 0.1 and less than or equal to 0.5.

As the content of M increases within the x range, hydrogen absorption characteristics may increase.

For example, in the case of TiFe _0.77 Mn _0.20 Cr _0.03 hydrogen storage alloy, the plateauing pressure may be 4 bar or less.

By substituting part of the Fe with Cr or Mn to partially form a Laves phase in the TiFe matrix, the hydrogen absorption characteristics are greatly improved compared to existing TiFe.

Part or all of Ti may be replaced with Zr.

By substituting Zr, hydrogen absorption ability can be improved and cycle performance can be improved.

Additionally, part or all of Ti may be replaced with V.

Activation characteristics can be improved by the V substitution.

Additionally, part of the Fe may be replaced with Co, Ni, Cu, or Al.

If the atomic fraction

_{For example ,} the TiFe _{1- x M} possible.

As the content of M (Cr, Mn, or a mixture thereof) increases within the x range, the hydrogen absorption characteristics may increase.

Additionally, hydrogen absorbed by the hydrogen storage alloy may be released from the hydrogen storage alloy through heat treatment.

At this time, the heating may be performed in a temperature range of 60°C to 150°C.

As a result, through the hydrogen storage system for storing liquefied hydrogen vaporized gas, a large amount of hydrogen can be absorbed in a hydrogen atmosphere with a pressure higher than the plateau pressure of the storage alloy at a fixed temperature, and the low-pressure hydrogen gas vaporized from liquefied hydrogen can be efficiently absorbed. A recyclable hydrogen storage alloy can be provided.

Figure 2 is a conceptual diagram schematically showing the gas flow of a hydrogen storage system for storing liquefied hydrogen vaporized gas according to an embodiment of the present invention.

Referring to FIG. 2, it can be seen that naturally vaporized gas within the liquefied hydrogen moves from the liquefied hydrogen storage tank unit 10 to the hydrogen storage unit 20 in the hydrogen storage system for storing liquefied hydrogen vaporized gas.

A method of controlling a hydrogen storage system for storing liquefied hydrogen vaporized gas according to another embodiment of the present invention will be described.

A hydrogen storage system control method for storing liquefied hydrogen vaporized gas according to another embodiment of the present invention,

A hydrogen gas absorption amount measurement step of measuring the absorption amount of hydrogen gas absorbed into the hydrogen storage alloy by moving hydrogen gas naturally vaporized inside the liquefied hydrogen storage tank to the hydrogen storage unit; And a control step of controlling the discharge of naturally vaporized hydrogen gas from the liquefied hydrogen storage tank by closing the valve when the absorption amount of hydrogen gas absorbed into the hydrogen storage alloy exceeds the preset reference amount compared to the preset reference amount. can do.

First, it may include a hydrogen gas absorption measurement step in which hydrogen gas naturally vaporized inside the liquefied hydrogen storage tank moves to the hydrogen storage unit and measures the absorption amount of hydrogen gas absorbed into the hydrogen storage alloy.

When the hydrogen gas naturally vaporized inside the liquefied hydrogen tank is discharged outside the liquefied hydrogen tank, the pressure inside the liquefied hydrogen storage tank is maintained at a pressure of 2 to 5 bar, and the hydrogen is vaporized to exceed a certain pressure (e.g. Once pressure (5 atmospheres) is formed, hydrogen gas can be discharged through the valve.

At this time, the hydrogen gas released at low pressure may be moved to a hydrogen storage unit including a hydrogen storage alloy installed and connected to the outside of the liquefied hydrogen storage tank.

At this time, the naturally vaporized hydrogen gas may be absorbed into the hydrogen storage alloy installed in the hydrogen storage unit.

In addition, since the hydrogen storage alloy has a limited amount of hydrogen that can be absorbed, the absorption amount of hydrogen gas absorbed into the hydrogen storage alloy can be measured.

The method of measuring the amount of hydrogen gas absorption can be done by measuring the change in weight of the actual storage alloy tank or by calculating the total amount absorbed by adding up the flow rate of hydrogen absorption.

In the second step, when the amount of hydrogen gas absorbed into the hydrogen storage alloy is compared to the preset standard amount and exceeds the preset standard amount, the valve is closed to control the discharge of naturally vaporized hydrogen gas from the liquefied hydrogen storage tank. May include steps.

The valve is located between the storage tank and the hydrogen storage unit to control the discharge of naturally vaporized hydrogen gas when the naturally vaporized hydrogen gas is discharged from the inside of the liquefied hydrogen storage tank.

At this time, when the amount of hydrogen gas absorbed into the hydrogen storage alloy exceeds the preset reference amount, the valve may be closed to control the discharge of the gas.

Additionally, the control step may further include a step of releasing hydrogen from the hydrogen storage alloy when the hydrogen storage alloy in which the hydrogen gas has been absorbed is heat treated.

The hydrogen storage alloy may have a plateauing pressure of 4 bar or less at 30°C.

At this time, the heating temperature that allows the hydrogen gas to be released may be 60°C to 150°C.

Hereinafter, the present invention will be described in more detail through manufacturing examples and experimental examples. However, the present invention is not limited to the following examples and experimental examples.

Manufacturing example 1

50 at% Ti, 38.5 at% Fe, 1.5 at% Cr, and 10 at% Mn were each weighed, placed in a crucible, heated, and then cooled to obtain TiFe _0.77 Mn _0.20 Cr _0.03 Hydrogen with the Laves phase partially precipitated in the TiFe alloy matrix. A storage alloy was prepared.

Experiment example

Figure 3 is a PCT diagram of a hydrogen storage alloy for storing liquefied hydrogen vaporized gas according to an embodiment of the present invention.

Referring to FIG. 3, hydrogen absorption characteristics were measured using PCT (pressure-concentration-temperature) equipment that analyzes hydrogen absorption/release behavior.

3 is a pct diagram taken at 30° C. of the TiFe _0.77 Mn _0.20 Cr _0.03 hydrogen storage alloy prepared according to the production example, and it can be seen that the pressure at which the slope of the plateau pressure of the hydrogen storage alloy becomes gentle is 4 bar or less. there is.

It can be confirmed that in the TiFe _0.77 Mn _0.20 Cr _0.03 hydrogen storage alloy, the slope of the plateau pressure becomes gentle, leaving 1.3 wt% of hydrogen remaining.

Figure 4 is a graph showing the hydrogen release pressure according to the DFT calculation formula and the DFT calculation results based on 50°C.

Referring to FIG. 4, it can be seen that the hydrogen evolution pressure increases as the reaction enthalpy increases, and among TiFe-based alloys, each alloy exhibits a proportional relationship in reaction enthalpy depending on the hydrogen evolution pressure.

In addition, referring to the calculation formula included in the graph of FIG. 4, when the discharge pressure is 1 atm based on 50°C, if the enthalpy of reaction with hydrogen is a negative value greater than the value derived from the calculation formula, the average value of the hydrogen storage alloy is This may mean that the suppression pressure is further lowered, so when the enthalpy of reaction with hydrogen according to the above calculation formula has a negative value greater than -35 kJ/mole, the plateau pressure of the hydrogen storage alloy may be 5 atmospheres or less.

Therefore, the TiFe-based alloy having a negative enthalpy greater than -35kJ/mole based on the hydride forming enthalpy (enthalpy of reaction with hydrogen) according to an embodiment of the present invention may have a plateauing pressure of 5 bar or less, and the It can well absorb liquefied hydrogen vaporized gas released below 5 bar.

The description of the present invention described above is for illustrative purposes, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. will be. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. For example, each component described as unitary may be implemented in a distributed manner, and similarly, components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the patent claims described below, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

Claims (10)

A storage tank unit including a liquefied hydrogen storage tank for storing liquefied hydrogen; and
A hydrogen storage unit installed outside the storage tank unit and including a hydrogen storage alloy that receives and absorbs naturally vaporized hydrogen gas from the liquefied hydrogen storage tank,
The hydrogen storage alloy has a plateau pressure lower than the discharge pressure of naturally vaporized hydrogen gas (BOG) inside the liquefied hydrogen storage tank, and the hydrogen storage alloy has a plateau pressure of 5 bar or less based on 30°C, and the Based on the reaction enthalpy, it has a negative enthalpy greater than -35 kJ/mole, and the hydrogen storage alloy is a TiFe-based alloy, TiMn ₂ -based alloy, LaNi ₅ -based alloy, or TiVCr-based alloy. Hydrogen storage system for storage. According to paragraph 1,
Liquefied hydrogen, characterized in that it further includes a valve located between the storage tank and the hydrogen storage unit to control the discharge of the naturally vaporized hydrogen gas when the naturally vaporized hydrogen gas is discharged from the inside of the liquefied hydrogen storage tank. Hydrogen storage system for storing vaporized gas. According to paragraph 1,
A hydrogen storage system for storing liquefied hydrogen vaporized gas, characterized in that the process of receiving and absorbing hydrogen gas from the hydrogen storage alloy is performed at a temperature of -100 ℃ to 30 ℃. delete delete According to paragraph 1,
A hydrogen storage system for storing liquefied hydrogen vaporization gas, characterized in that hydrogen absorbed by the hydrogen storage alloy can be released from the hydrogen storage alloy by heat treatment. delete In the method of controlling a hydrogen storage system for storing liquefied hydrogen vaporized gas using the hydrogen storage system for storing liquefied hydrogen vaporized gas of claim 1,
A hydrogen gas absorption amount measurement step of measuring the absorption amount of hydrogen gas absorbed into the hydrogen storage alloy by moving hydrogen gas naturally vaporized inside the liquefied hydrogen storage tank to the hydrogen storage unit; and
A control step of controlling the discharge of naturally vaporized hydrogen gas from the liquefied hydrogen storage tank by closing the valve when the absorption amount of hydrogen gas absorbed into the hydrogen storage alloy exceeds the preset reference amount compared to the preset reference amount. However,
The hydrogen storage alloy has a plateau pressure lower than the discharge pressure of naturally vaporized hydrogen gas (BOG) inside the liquefied hydrogen storage tank, and the hydrogen storage alloy has a plateau pressure of 5 bar or less based on 30°C, and the Based on the reaction enthalpy, it has a negative enthalpy greater than -35 kJ/mole, and the hydrogen storage alloy is a TiFe-based alloy, TiMn ₂ -based alloy, LaNi ₅ -based alloy, or TiVCr-based alloy. Hydrogen storage system control method for storage. According to clause 8,
In the control step, the method of controlling a hydrogen storage system for storing liquefied hydrogen vaporized gas further comprises a step of releasing hydrogen from the hydrogen storage alloy when the hydrogen storage alloy in which the hydrogen gas has been absorbed is heat treated. delete

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