AU2023277401B2 - Modular hydrogen liquefaction system - Google Patents

Abstract

A modular hydrogen liquefaction system, comprising: one or more liquefaction modules (2.1-2.k) arranged in parallel. Hydrogen inlets of the liquefaction modules (2.1-2.k) are connected to a hydrogen gas source (1); product outlets of the liquefaction modules (2.1-2.k) are connected to one or more liquid hydrogen storage tanks (3.1-3.j) connected in parallel; and each liquefaction module (2.1-2.k) is of an integrated structure that can cool and liquefy hydrogen, can complete orthohydrogen/parahydrogen conversion, and can be independently started/stopped.

Description

MODULARHYDROGEN MODULAR HYDROGEN LIQUEFACTIONSYSTEM LIQUEFACTION SYSTEM TECHNICALFIELD TECHNICAL FIELD

[0001]

[0001] TheThe present present disclosure disclosure belongs belongs to the to the technical technical field field of of cryogenic cryogenic equipment, equipment, and and

particularlyrelates particularly relatestotoa amodular modular hydrogen hydrogen liquefaction liquefaction system. system.

BACKGROUND BACKGROUND ART ART DISCUSSION DISCUSSION

[0002] In recent

[0002] In recent years, years, to facilitate to facilitate the the achievement achievement of carbon of carbon peaking peaking and carbonand carbon neutrality, neutrality,

further promote further promote thethe revolution revolution in in energy productionand energy production andconsumption, consumption, andand establish establish a clean, a clean,

low-carbon,safe, low-carbon, safe, and efficient society, and efficient society, hydrogen hydrogen energy energy has has emerged emerged as as one one of of the the long-term long-term

solutions to solutions to address current energy address current energyissuesissuesand andrealize realizethe thestrategic strategic goals goals of of "dual "dualcarbon" carbon" (carbon peaking (carbon peakingand andcarbon carbonneutrality). neutrality). Hydrogen Hydrogen energyenergyisisaasecondary secondaryenergyenergysourcesourcethat thatisis abundant,green, abundant, green, low-carbon, low-carbon, and widely and widely applicable. applicable. It alsoasserves It also serves as a and a crucial crucial and large-scale large-scale

chemicalraw chemical rawmaterial. material.Hydrogen Hydrogen produced produced by using by using renewable renewable energy energy sourcessources such such as wind as wind

and solar and solar power, power,alsoalso known known as as "green "green hydrogen," hydrogen," represents represents the the primary primary futurefuture sourcesource of of hydrogen hydrogen energy. energy. It can It can be utilized be utilized in the intransportation, the transportation, civilian, civilian, and storage and energy energysectors storage sectors of electricity of electricity production, production,andand is is alsoalso expected expected to betoused be used extensively extensively in the chemical in the chemical industry, industry,

suchasasreplacing such replacing coke coke as aas a reducing reducing agent.agent.

[0003]

[0003] ToTo achieve achieve a reasonable a reasonable andand economically economically viable viable priceprice for for hydrogen hydrogen at theat the end-user end-user

level, thereby level, therebyenabling enabling large-scale large-scale market market adoption, adoption, the key the key technical technical challenge challenge lies in safe lies in safe

and efficient and efficient storage storage and transportation. High-pressurized and transportation. hydrogenstorage High-pressurized hydrogen storageat atthetheambient ambient temperaturehas temperature hasthe thehighest highesttechnical technical maturity, maturity, and and has hasbeen beenwidely widelyused; used;however, however, itsits low low

storage and storage and transportation transportation densitydensity and and high high well-to-wheel well-to-wheelcosts costsrender renderitit uneconomical uneconomical and and

unsuitable for unsuitable for large-scale large-scale application application based based on current technological on current technological trends.trends. Material-based Material-based

hydrogenstorage hydrogen storagetechnologies, technologies, including including physical physical adsorption, adsorption, chemical chemical adsorption, adsorption, and and liquid organic liquid organichydrogen hydrogen carrier carrier (LOHC), (LOHC), are stillareatstill at a relatively a relatively low of low level level of technical technical maturitymaturity

and lack and lack economies economiesofofscale. scale. They Theyalso alsosuffer suffer from fromissues issues such suchas as high high well-to-wheel well-to-wheelenergy energy consumption,high consumption, highequipment equipment and and material material costs, costs, systemsystem complexity, complexity, and product and product purity purity

concerns, making concerns, makingthem them impractical impractical forfor large-scaleapplication. large-scale application.OnOnthe theother otherhand, hand,thanks thankstoto the increasingly the maturecryogenic, increasingly mature cryogenic,multilayer multilayerinsulation, insulation, andandvacuum vacuum technologies, technologies, storing storing

and transporting and transportingcryogenic cryogenicliquefied liquefied hydrogen hydrogen offers offers higherhigher storage storage density density and lower and lower

operating pressures. operating pressures.This Thisreduces reducesenergy energy consumption consumption and space costs and space costs perper unit unit mass mass transported, making transported, making itit aa promising promisingmethod method for for long-distance long-distance hydrogen hydrogen transportation transportation and and

large-scale storage. large-scale storage. It It represents represents the theonlyonlytechnical technical pathway pathway capablecapable of achieving of achieving an an economically economically viable viable priceprice for hydrogen for hydrogen at the at the end-user end-user level. level.

[0004] Using

[0004] Using renewable renewable energy energy sources sources suchsuch as wind as wind and and solarsolar powerpower to produce to produce and and liquefy liquefy hydrogenrepresents hydrogen representsananimportant importantmode modeforfor futuregreen future green hydrogen hydrogen production. production. However, However, the the intermittency of intermittency of renewable energypower renewable energy powergeneration generation poses poses specialrequirements special requirements on on thethe green green hydrogenproduction hydrogen production systems systems (electrolyzer (electrolyzer and and hydrogen hydrogen liquefaction liquefaction systems) systems) that arethat are associated with associated downstreamprocesses: with downstream processes:

[0005]

[0005] 1.1.Adjustable Adjustable capacity capacity andand rapid rapid start-up/shutdown: start-up/shutdown: If theIf the greengreen liquid liquid hydrogen hydrogen

production production system system operates operates continuously continuously and stably, and stably, it must it mustbeeither either be equipped equipped with an energy with an energy

storagesystem storage system that that is is large large enough enough to supply to supply sufficient sufficient power,power, or use electricity or use electricity from thefrom grid the grid

to maintain to the production maintain the during periods production during periods of of low low electricity electricity generation. generation.However, the former However, the former

methodrequires method requiresaahigh-cost high-costenergy energystorage storagesystem system(currently (currentlystill still more expensivecompared more expensive compared to the to the green hydrogenproduction green hydrogen production system system with with the the samesame installed installed capacity) capacity) and and occupies occupies a a large area, large area, significantly significantlyincreasing increasing capital capital expenditure expenditure (CAPEX)(CAPEX) and, consequently, and, consequently, resulting resulting in high in hydrogen high hydrogen costs. costs. The The latter latter option option involves involves grid electricity grid electricity prices prices that arethat muchare much higher higher

thanthe than theoff-grid off-gridprices, prices,resulting resultinginina asteep steepincrease increase in in operating operating expenses expenses (OPEX). (OPEX). Moreover,Moreover, the entire the entire system system stillimposes still imposes significant significant fluctuation fluctuation impactsimpacts on the on the grid, grid, to failing failing to mitigate mitigate

the impact the impactofofrenewable renewable energy energy intermittency intermittency on grid on the the grid throughthrough hydrogen hydrogen production. production.

Therefore, the Therefore, the green greenhydrogen hydrogen production production system system (including (including electrolyzer electrolyzer and hydrogen and hydrogen

liquefaction systems) liquefaction systems)needs needs to have to have adjustable adjustable capacity capacity andstart-up/shutdown and rapid rapid start-up/shutdown capabilities. By selecting appropriate capacity or start-up/shutdown strategies, it can match capabilities. By selecting appropriate capacity or start-up/shutdown strategies, it can match

the intermittent the intermittentrenewable renewable energy systemand energy system andachieve achievea afully fully off-grid off-grid production mode. production mode.

[0006]

[0006] 2. 2. Lower LowerCAPEX:CAPEX: A green A green liquidliquid hydrogen hydrogen production production system system withwith adjustable adjustable

capacityand capacity andrapid rapid start-up/shutdown start-up/shutdown capabilities, capabilities, also experiences also experiences a corresponding a corresponding reduction reduction

in equipment in utilization equipment utilization rate rate cooperating cooperating with with intermittent intermittent renewablerenewable energy production. energy production. This This makes the makes the CAPEX CAPEX of of thethegreengreen liquidhydrogen liquid hydrogen productionsystem production system a more a more significant significant proportion of proportion of the the terminal terminalhydrogen hydrogen cost cost composition, composition, becoming becoming the mostthecrucial most crucial factor factor

affecting hydrogen affecting hydrogen price.price.Therefore, Therefore,totoreducereducethethe CAPEX CAPEX of theofgreen the green liquid liquid hydrogen hydrogen production system production systemisisa anecessary necessarycondition conditionforforthethegreen green hydrogen hydrogen production production mode mode to be to be

competitive in competitive in the the market. market.

[0007] Hydrogen

[0007] Hydrogen liquefaction liquefaction is is thethe most most criticallink critical link inin the the green green hydrogen industrychain, hydrogen industry chain, characterized characterized by complextechnological by complex technologicalprocesses, processes,high highenergy energyconsumption, consumption, andand substantial substantial

investmentcosts. investment costs. Over Overthe thepast pastfewfewdecades, decades,numerous numerous researchers researchers havehave been been focusing focusing on on enhancingthe enhancing theefficiency efficiency of of liquefaction liquefaction process process that that can can effectively effectively reduce both the reduce both the OPEX OPEX directly and,indirectly, directly and, indirectly,thetheCAPEX CAPEX of a hydrogen of a hydrogen liquefaction liquefaction plant. plant.

[0008] Accordingtotothethedifferent

[0008] According differentrefrigerants refrigerants and and thermodynamic thermodynamiccycles, cycles,existing existing commercialliquefaction commercial liquefactionplants plants usually usually useuse either either thethe helium-based reversed Brayton helium-based reversed Braytoncycle cycleor or the hydrogen-based the modified hydrogen-based modified Claude Claude cycle. cycle. TheThe former former is commonly is commonly used used in small/medium- in small/medium-

scale liquefaction scale liquefactionsystems systemswithwith a capacity a capacity of lessofthan less5 than 5 ton/day, ton/day, while thewhile latterthe is latter is typically typically

appliedininlarge-scale applied large-scaleliquefaction liquefaction systems systems with awith a capacity capacity exceeding exceeding 5 ton/day.5 ton/day.

[0009] Conventional

[0009] Conventional hydrogen hydrogen liquefaction liquefaction systems systems typically typically consistconsist of a pre-cooling of a pre-cooling

system, system, aa main mainrefrigeration refrigerationsystem, system, a liquefaction a liquefaction system, system, and and a seta of setcryogenic of cryogenicheat heat

2 exchangers.The exchangers. Thepre-cooling pre-cooling system system usually usually uses uses a relatively a relatively mature mature process process to achieve to achieve refrigeration atataround refrigeration around70-120 70-120 K, providing providing pre-cooling pre-cooling forfor thethe main main refrigerationsystem refrigeration system andand the liquefaction the liquefaction system. system. The Themain main refrigerationsystem refrigeration system equipped equipped with with compressor(s) compressor(s) and and expander(s), exchanges expander(s), exchangesheatheat with with the the hydrogen hydrogen in theinliquefaction the liquefaction system system through through the the cryogenicheat cryogenic heat exchangers exchangers set, set, to cool to cool the hydrogen, the hydrogen, finallyfinally liquefyliquefy the hydrogen. the hydrogen. Specifically, Specifically, the compressor(s) the compresses compressor(s) compresses therefrigerant the refrigeranttotoaahigh highpressure, pressure,providing providinghigh-pressurized high-pressurized refrigerantfor refrigerant forthe themain main refrigeration refrigeration system system cycle.cycle. Via Via the the expander(s), expander(s), the high-pressurized the high-pressurized refrigerantexpands refrigerant expandsto to generate generate cooling, cooling, supplying supplying coldtoenergy cold energy to the liquefaction the liquefaction system. In system. In the cryogenic heat exchanger set, a plurality of ortho-para hydrogen converters (which can be the cryogenic heat exchanger set, a plurality of ortho-para hydrogen converters (which can be either continuous either continuous isothermal isothermal reactors reactors or stepwise or stepwise adiabatic adiabatic reactors) reactors) are to are equipped equipped convert to convert ortho-hydrogen ortho-hydrogen totopara-hydrogen para-hydrogen untilthetheequilibrium until equilibrium ratioofofortho- ratio ortho-andandpara-hydrogen para-hydrogenat at the current the current heat heatexchanger exchanger temperature. temperature. TheThe feed feed hydrogen suppliedfrom hydrogen supplied fromthe the hydrogen hydrogensource source sequentially passes sequentially passes through throughthe theortho-para ortho-parahydrogen hydrogen converters converters within within the the multistage multistage heatheat exchangers exchangers andand finally finally enters enters the liquid the liquid hydrogen hydrogen storage storage tank in a tank liquidin a liquid state, state, and finally and finally flowsout flows outthrough through the the product product outlet. outlet.

[0010]

[0010] ItItisis evident evident that that conventional conventional hydrogen liquefaction technology hydrogen liquefaction technologycannot cannotmeet meetthe thetwo two requirementsfor requirements forgreen greenliquid liquidhydrogen hydrogen production production fromoff-grid from the the off-grid renewable renewable energy energy sources: sources:

[0011] Conventional

[0011] Conventional hydrogen hydrogen liquefaction liquefaction technology technology employs employs large large compressors, compressors, turbo- turbo-

expanders,andand expanders, heat heat exchangers. exchangers. During During the cool-down the cool-down process, theprocess, theisflow flow rate rate is relatively relatively low, low, causingthe causing theturbo-expander turbo-expander to operate to operate far away far away from from its its normal normal conditions, conditions, resulting resulting in a small in a small

circulatingflow circulating flowrate rateand and correspondingly correspondingly low refrigeration low refrigeration capacity. capacity. Consequently, Consequently, the startupthe startup

(cool-down) (cool-down) and andshutdown shutdown processes processes require require a significantamount a significant amount of oftimetime (typically (typically ranging ranging

from 66 to from to 18 18 hours). hours). Furthermore, Furthermore, to to protect protect thethe rotating rotatingequipment equipment such such as as compressors compressorsand and expanders, the expanders, thestartup startup and andshutdown shutdown procedures procedures are very are very complex. complex. Although Although the use of the use of variablefrequency variable frequency compressors compressors or selectively or selectively shutting shutting down down a few of a few the of thecompressors parallel parallel compressors can adjust can adjust the the production capacityofof the production capacity the hydrogen hydrogenliquefaction liquefactionsystemsystem to tosomesome extent, extent, thethe

adjustment adjustment range range is relatively is relatively limited, limited, and and therethere is a noticeable is a noticeable decreasedecrease in energy inefficiency. energy efficiency.

[0012]

[0012] The Thecorecorecomponents components of of conventional conventional hydrogen hydrogen liquefaction liquefaction plants,such plants, suchas as compressors,heat compressors, heatexchangers, exchangers, and and turbo-expanders, turbo-expanders, are allare all large, large, custom-madecustom-made parts parts available in limited quantities, leading to long delivery times and high prices. As a typical available in limited quantities, leading to long delivery times and high prices. As a typical

chemicalengineering chemical engineeringproject, project, both both thethe equipment equipment and andengineering engineeringrequire requirecustom customdesign. design.The The entire project, entire project, from fromcontract contract negotiation, negotiation, conceptual conceptual design,design, construction, construction, to final to final

commissioning commissioning and and operation, operation, requiresa avery requires verylong longproject projecttime time(24 (24toto3636months). months).The The non- non-

standard products standard products and andcustomized customizedengineering engineering inevitablyresult inevitably resultinin high high CAPEX. CAPEX.

SUMMARY SUMMARY OFOFTHE THEINVENTION INVENTION

[0013] Based

[0013] Based on on thethe demand demand for for green green liquid liquid hydrogen hydrogen production production modemode associated associated with with the the

3 off-grid off-grid renewable energy, the renewable energy, the present present disclosure disclosure proposes proposes aa modular modularhydrogen hydrogen liquefaction liquefaction system that features adjustable production capacity, rapid startup and shutdown capabilities, system that features adjustable production capacity, rapid startup and shutdown capabilities, low CAPEX, low CAPEX, and and the the ability ability to to quickly quickly deployment. deployment. To achieve To achieve this,this, the the present present disclosure disclosure adoptsthe adopts thefollowing following technical technical solution: solution:

[0014]

[0014] A A modular modular hydrogen hydrogen liquefaction liquefaction system,system, comprising: comprising: one liquefaction one or more or more liquefaction devicesarranged devices arranged in in parallel, parallel, wherein wherein a hydrogen a hydrogen inlet ofinlet of the liquefaction the liquefaction device isdevice is connected connected

to aa hydrogen to hydrogen gasgas source, source, and aand a product product outlet outlet of the of the liquefaction liquefaction device isdevice is connected connected to one to one or more or liquid hydrogen more liquid hydrogenstorage storagetanks tanksthat thatare areconnected connected in in parallel;and parallel; andeach eachliquefaction liquefaction device is of an integrated structure with functions of hydrogen cooling, liquefaction and ortho- device is of an integrated structure with functions of hydrogen cooling, liquefaction and ortho-

para hydrogen para conversionand hydrogen conversion andisisarranged arrangedtotostart-up start-up and andshut-down shut-downindependently. independently.

[0015]

[0015] TheThe hydrogen hydrogen gas gas source source and and the the liquid liquid hydrogen hydrogen storage storage tanktank can can be independently be independently

arranged, andcan arranged, and canalso alsobebepart partof of thethe present present disclosure. disclosure. When When the system the system is usedis as used a as a

componentofofthe component thepresent presentdisclosure, disclosure,the the modular modularhydrogen hydrogen liquefaction liquefaction system system comprises comprises a a hydrogengas hydrogen gassource, source,aaliquefaction liquefaction device device andandaa liquid liquid hydrogen hydrogenstorage storagetank, tank,the the hydrogen hydrogen gas source, gas source, the the liquefaction liquefaction device deviceand andthetheliquid liquidhydrogen hydrogen storage storage tanktank are are sequentially sequentially

connectedthrough connected throughpipelines. pipelines.Room-temperature Room-temperature hydrogen hydrogen from from the hydrogen the hydrogen gas source gas source is is cooled, liquefied, cooled, liquefied, and and subjected subjected to to ortho-para ortho-para hydrogen conversionthrough hydrogen conversion through theliquefaction the liquefaction device before flowing into the liquid hydrogen storage tank for storage. device before flowing into the liquid hydrogen storage tank for storage.

[0016]

[0016] The The liquefactionsystem liquefaction system in in thepresent the presentdisclosure disclosurecomprises comprises oneone or or more more (quantified (quantified

as k, as k, where k≥1)liquefaction where k>1) liquefactiondevices devicesconnected connected in in parallel.These parallel. Theseliquefaction liquefactiondevices devicesare are standardized skid-mountedunits, standardized skid-mounted units, adopting adoptingstandard standardcontainer container dimensions dimensionsand andinterfaces, interfaces, with with each device capable each device capableofofindependent independentoperation operation to to cool,liquefy, cool, liquefy,and andcomplete complete thethe ortho-para ortho-para

hydrogenconversion hydrogen conversionofofa acertain certainflow flowrate rate of of hydrogen. hydrogen.The Theliquid liquidhydrogen hydrogenproduct product outlets outlets

of the of the paralleled paralleledliquefaction liquefaction devices devices converge converge into a into singlea single main via main pipeline pipeline via piping, piping, which which

is then is connectedtotothe then connected theliquid liquidhydrogen hydrogen storage storage tank.tank. ThisThis design design offers offers the following the following

advantages: advantages:

1．A plurality ofofdevices 1. A plurality devicesconnected connected in in parallel parallel enable enable larger larger hydrogen hydrogen liquefaction liquefaction

capacity; capacity;

2．Independent 2. operation Independent operation of of one one or or more more devices devices allows allows for for a wide a wide rangerange of capacity of capacity

adjustmentwithout adjustment withoutcompromising compromising system system energy energy efficiency; efficiency;

3．Users 3. canflexibly Users can flexiblyandand conveniently conveniently expand expand or reduce or reduce system system capacity, capacity, thereby thereby

mitigating investment risks; mitigating investment risks;

4．Standardized 4. devices Standardized devices facilitate facilitate large-scale large-scale production, production, significantly significantly reducing reducing

equipmentcosts; equipment costs; 5．The complexity 5. The complexity ofof system system installationisis minimized, installation minimized,leading leadingtotoreduced reducedconstruction construction costs and time; costs and time;

6．Skid-mounted 6. devices Skid-mounted devices are are convenient convenient for inventory for inventory management, management, transportation, transportation,

lifting, and layout. lifting, and layout.

4

[0017] Preferably,the

[0017] Preferably, theliquefaction liquefaction device devicecomprises: comprises: a pre-cooling a pre-cooling unit unit for forpre-cooling pre-cooling hydrogen; hydrogen;

a cryogenic a cryogenicliquefaction liquefactionconversion conversion unitunit for liquefying for liquefying pre-cooled pre-cooled hydrogen hydrogen and and converting the converting the pre-cooled pre-cooled hydrogen hydrogentotoliquid liquidhydrogen hydrogen and and performing performing ortho-para ortho-para hydrogen hydrogen

conversion; conversion;

an expansion an expansion unit unit forfor reducing reducing pressure pressure of theof the hydrogen hydrogen after cryogenic after cryogenic liquefactionliquefaction and and ortho-para hydrogen ortho-para hydrogenconversion, conversion,wherein wherein an an outletofofthe outlet theexpansion expansionunitunitisis used usedas as aa product product outlet and outlet andisisconnected connectedto to thethe liquid liquid hydrogen hydrogen storage storage tank; and tank; and

a compression a compressionunit unitforforproviding providing compression compression works works to the to the cryogenic cryogenic liquefaction liquefaction

conversion unit. conversion unit.

[0018]

[0018] TheThe compression compression unitunit is connected is connected to atostandard a standard refrigeration refrigeration unit unit in in thethecryogenic cryogenic liquefaction conversion liquefaction conversion unitunit by means by means of a pipeline. of a pipeline.

[0019] Preferably,the

[0019] Preferably, thepre-cooling pre-coolingunit unitcomprises: comprises: a pre-cooling a pre-cooling heat heat exchanger; exchanger;

a pre-cooling a pre-cooling cold cold source for providing source for providing cooling for the cooling for the pre-cooling pre-cooling heat heat exchanger; exchanger; and and

a purifier a purifier and and aa pre-cooling-stage ortho-para hydrogen pre-cooling-stage ortho-para hydrogenconverter converter thatarearesequentially that sequentially connectedtoto aa hydrogen connected hydrogenflow flowchannel channelofofthe thepre-cooling pre-coolingheat heatexchanger. exchanger.

[0020]

[0020] The Thepre-cooling pre-cooling heat heat exchanger exchanger comprises comprises aa hydrogen hydrogen flow flow channel channel and and aa pre- pre- coolingrefrigerant cooling refrigerantflow flow channel; channel; andpre-cooling and the the pre-cooling coldprovides cold source source pre-cooling provides pre-cooling to the to the hydrogenvia hydrogen viathe thepre-cooling pre-coolingrefrigerant. refrigerant. TheTheflowflowchannel channel of of thethe pre-cooling pre-cooling stage stage ortho- ortho-

para hydrogen para hydrogenconverter converter is is provided provided withwith ortho-para ortho-para hydrogen hydrogen catalyst catalyst inside. inside. In actual In actual

connection, connection, the the interface interface of of the the hydrogen hydrogen gasgas source, source, the the hydrogen hydrogenflow flowchannel channel of of thethepre- pre- coolingheat cooling heatexchanger, exchanger, the the purifier, purifier, and and the pre-cooling the pre-cooling stage ortho-para stage ortho-para hydrogen hydrogen converter converter

are connected are connected through through pipelines; pipelines; the pre-cooling the pre-cooling coldissource cold source is connected connected to a cold endto inlet a cold end inlet of the of the pre-cooling refrigerant flow pre-cooling refrigerant flow channel channel of of the the pre-cooling pre-cooling heat heat exchanger exchangervia viapipelines, pipelines, andthe and thepre-cooling pre-cooling refrigerant refrigerant flows flows through through the pre-cooling the pre-cooling refrigerant refrigerant flow flow channel of channel the of the pre-cooling heat pre-cooling heat exchanger exchanger to to provide provide cooling cooling forfor the the hydrogen flowingthrough hydrogen flowing throughthe the hydrogen hydrogen flowchannel flow channel of of thethe pre-cooling pre-cooling heat heat exchanger, exchanger, the purifier, the purifier, and the and the pre-cooling pre-cooling stage ortho- stage ortho- para hydrogen para hydrogenconverter. converter.DuringDuring actual actual operation, operation, thethe room-temperature room-temperature hydrogen hydrogen with a with a

pressure of pressure of P Psupply supply from from the the hydrogen hydrogen gasgas source source is first is first precooled precooled to theto pre-cooling the pre-cooling temperature temperature TpreC TpreC through through the pre-cooling the pre-cooling heat exchanger; heat exchanger; then then passes passes through thethrough purifier the to purifier to

removethe remove thegaseous gaseous andandsolidsolid impurities impurities from from the the feedfeed hydrogen, hydrogen, preventing preventing blockage blockage of of subsequentprocesses subsequent processesand andensuring ensuringthethepurity purityofofthetheliquid liquidhydrogen hydrogenproduct; product; thetheprecooled precooled and purified and purified feed feed hydrogen enters the hydrogen enters the pre-cooling-stage pre-cooling-stage ortho-para ortho-para hydrogen converter, where hydrogen converter, where

the ortho-para the ortho-para conversion conversionoccurs occurswith withthethe assistance assistance of of thethe ortho-para ortho-para hydrogen hydrogen catalyst, catalyst,

causing the causing the para-hydrogen para-hydrogen content contentininthethe hydrogen hydrogentotoapproach approachitsitsequilibrium equilibriumconcentration concentration at the at the pre-cooling temperature pre-cooling temperature TpreCTpreC and and restoring restoring the hydrogen the hydrogen temperature temperature to the pre-cooling to the pre-cooling

temperature temperature TpreC. TpreC.

[0021] Preferably,the

[0021] Preferably, thepurifier purifierisis aa cryogenic cryogenicpurification purification adsorber. adsorber. TheThepurifier purifiercan canbebea a single cryogenic single cryogenicpurification purificationadsorber adsorberor ortwotwo or more or more cryogenic cryogenic purification purification adsorbers adsorbers configured in parallel. Further preferably, the purifier comprises two cryogenic purification configured in parallel. Further preferably, the purifier comprises two cryogenic purification adsorbersthat adsorbers thatareareswitched switched through through valvesvalves and alternately and alternately connected connected to the The to the pipeline. pipeline. two The two cryogenic purification adsorbers, cryogenic purification adsorbers, connected connectedininparallel, parallel,form forma atypical typicaltemperature temperature swing swing adsorption (TSA) adsorption (TSA)unit. unit. When When oneone of of thecryogenic the cryogenic purificationadsorbers purification adsorbers isisconnected connected to to the the pipeline, the pipeline, the other other oneone that that is isnot notconnected connected isis purged and heated purged and heatedbybyclean cleaninert inert hot hot gas gastoto achieve regeneration, achieve regeneration, thereby thereby enhancing enhancingthe theoperating operatingefficiency efficiencyofofthe thehydrogen hydrogencryogenic cryogenic purificationadsorber. purification adsorber.

[0022]

[0022] The The pre-cooling-stage pre-cooling-stage ortho-para ortho-para hydrogen hydrogen converter converter and itsand its corresponding corresponding pre- pre- cooling heat cooling heat exchanger exchangercan canadopt adopt eitheranan either integratedstructure integrated structureorora amutually mutually independent independent

structure. The structure. Theformer former is continuous is continuous isothermal isothermal reactor,reactor, essentially essentially involving involving the filling the of afilling of a

catalyst within catalyst withinthetheflow flow channel channel of aof a cryogenic cryogenic heat exchanger; heat exchanger; here, thehere, theserves reactor reactor as serves the as the heat exchanger, heat exchanger,simultaneously simultaneouslycompleting completing the the ortho-para ortho-para hydrogen hydrogen catalytic catalytic reaction reaction and and

achievingcooling achieving coolingof of thethe in-flow in-flow hydrogen. hydrogen. The is The latter latter is adiabatic adiabatic stepwisestepwise reactor, reactor, essentially essentially

comprising comprising a separate a separate adiabatic adiabatic container container provided provided with catalyst; with catalyst; in this in this case, case,first hydrogen hydrogen first passes through passes throughthe the corresponding correspondingcryogenic cryogenic heatheat exchanger exchanger for for cooling cooling before before entering entering the the

reactor for reactor for the the ortho-para ortho-para reaction, reaction, resulting resulting in in aatemperature temperatureincrease, increase,andand then then passes passes

through aa subsequent through cryogenicheat subsequent cryogenic heatexchanger exchangerfor forfurther further cooling. cooling. The The continuous isothermal continuous isothermal

reactor offers reactor offers higher efficiency and higher efficiency andaamore more compact compact structure structure compared compared to thetoadiabatic the adiabatic stepwise reactor, stepwise reactor, while the adiabatic while the adiabatic stepwise reactor is stepwise reactor is simpler in terms simpler in of manufacturing terms of manufacturing and processing. and processing.Both Bothstructures structurescancan be be applied applied in technical in the the technical solution solution ofpresent of the the present disclosure. disclosure.

[0023] Depending

[0023] Depending on the on the different different conditions conditions at the at the sitesite where where the the hydrogen hydrogen liquefaction liquefaction

systemis system is located, located, the the pre-cooling pre-cooling cold cold source source can can be be either either an an open-loop cryogensystem open-loop cryogen systemoror a closed-loop a closed-loop cryogenic cryogenicrefrigeration refrigerationpre-cooling pre-coolingsystem. system. TheThe open-loop open-loop cryogencryogen systemsystem

utilizes liquid utilizes liquidnitrogen nitrogenororliquefied liquefied natural naturalgasgas (LNG) (LNG)as asthethecooling coolingmedium. medium. TheTheformer formerisis particularlysuitable particularly suitableforforsituations situations where where stablestable and inexpensive and inexpensive liquid isnitrogen liquid nitrogen available is available on-site, suchasaswhen on-site, such when therethere is a is a nearby nearby air separation air separation unit capable unit capable of providing of providing a stable anda stable and

cost-effectivesupply cost-effective supplyof of liquid liquid nitrogen. nitrogen. The latter The latter is especially is especially suitablesuitable for applications for applications like like LNGports LNG portswhere whereit it isisnecessary necessarytotorecover recoverthethecold coldenergy energy from from thethe vaporization vaporization of LNG. of LNG.

Theclosed-loop The closed-loopcryogenic cryogenicrefrigeration refrigerationpre-cooling pre-coolingsystem systemcan canbebea areversed-Brayton reversed-Brayton cycle cycle

refrigerationsystem, refrigeration system, a cascaded a cascaded mixture mixture refrigeration refrigeration system, system, or a regenerative or a regenerative refrigerationrefrigeration system, which system, which areare suitable suitable for for scenarios scenarios wherewhere electricity electricity is inexpensive is inexpensive or whereoritwhere it is difficult is difficult

to obtain to obtain cryogen such as cryogen such as liquid liquid nitrogen nitrogen or or LNG on-site. LNG on-site.

[0024]

[0024] AsAs a specific a specific preferred preferred solution, solution, thethe pre-cooling pre-cooling coldcold source source is provided is provided by the by the following pre-cooling following pre-cooling circulation circulation system: system:

a turbo-compressor a turbo-compressor for forcompressing compressinga apre-cooling pre-coolingrefrigerant refrigeranttoto high high pressure; pressure; a driving a driving motor for driving motor for driving the the turbo-compressor; turbo-compressor;

a water a water cooler cooler for for cooling cooling aa high-pressurized high-pressurized gas gas output output fromfrom the the turbo-compressor; turbo-compressor;

6 a cryogenic a turbo-expanderfor cryogenic turbo-expander for expanding expandingand andcooling coolingthe thepre-cooling pre-coolingrefrigerant refrigerant output output from an from an in-flow in-flow channel channelofofthe the pre-cooling pre-cooling heat heat exchanger; exchanger;and and a hydrogen flow channel, the in-flow channel for the pre-cooling refrigerant and a return- a hydrogen flow channel, the in-flow channel for the pre-cooling refrigerant and a return- flow channel flow channelfor for the the pre-cooling pre-cooling refrigerant refrigerant are are arranged arranged in in the the pre-cooling pre-cooling heat heat exchanger; exchanger; whereinanan wherein inletofofthethein-flow inlet in-flow channel channel for pre-cooling for the the pre-cooling refrigerant refrigerant is connected is connected to an outlet to an outlet of the of the water cooler,ananoutlet water cooler, outletofofthe thein-flow in-flow channel channel for for the the pre-cooling pre-cooling refrigerant refrigerant is connected is connected to an to aninlet inletofofthe thecryogenic cryogenic turbo-expander, turbo-expander, anofinlet an inlet of the return-flow the return-flow channel channel for the pre-for the pre- cooling refrigerantisisconnected cooling refrigerant connectedto antooutlet an outlet of cryogenic of the the cryogenic turbo-expander, turbo-expander, and of and an outlet an outlet of the return-flow channel for the pre-cooling refrigerant is connected to an inlet of the turbo- the return-flow channel for the pre-cooling refrigerant is connected to an inlet of the turbo- compressor. compressor.

[0025] Furtherpreferably,

[0025] Further preferably,the theturbo-compressor turbo-compressor recovers recovers expansion expansion workwork generated generated by the by the

cryogenic turbo-expander through cryogenic turbo-expander through aa connecting connectingshaftshaft connected connectedbetween betweenthethe turbo- turbo-

compressorand compressor andthe thecryogenic cryogenicturbo-expander. turbo-expander.

[0026] Preferably,the

[0026] Preferably, theliquefaction liquefactiondevice devicefurther furthercomprises comprises a vacuum-insulated a vacuum-insulated cold-box cold-box

and aa radiation and radiation shield. shield. The Theradiation radiationshield, shield, the the pre-cooling pre-coolingunit unit(cryogenic (cryogenicsection), section),the the expansionunit, expansion unit, and andthe thecryogenic cryogenic section section of the of the cryogenic cryogenic liquefaction liquefaction conversion conversion unit unit

(including the (including the cold cold finger finger ofofthe thestandard standardrefrigeration refrigerationunit unitand andthe theortho-para ortho-para hydrogen hydrogen

converter) are converter) are installed installed within within the thevacuum-insulated vacuum-insulated cold-box. cold-box. The The innerinner portion portion of theof the vacuum-insulatedcold-box vacuum-insulated cold-box is is evacuated evacuated to to minimize minimize convective convective and conductive and conductive heat leaks heat leaks

from the from the ambient. ambient.The Thelowest lowesttemperature temperature sections sections of of thethe expansion expansion unit unit andand thethe cryogenic cryogenic

liquefactionconversion liquefaction conversion unitunit are are positioned positioned withinwithin the radiation the radiation shield. shield. The radiation The radiation shield is shield is

constructedfrom constructed from a thin a thin metal metal shellshell withwith good good thermalthermal conductivity, conductivity, and itsissurface and its surface polishedis polished to achieve to achievea ahighhigh reflectivity. reflectivity. It It is is thermally thermally connected connected to theto the pre-cooling pre-cooling coldandsource cold source is and is cooledtotothe cooled thepre-cooling pre-cooling temperature temperature TpreCTby bypre-cooling the preC the pre-cooling refrigerant. refrigerant. The radiation The radiation shield shield surroundsthethelowest surrounds lowest temperature temperature (cold (cold head) head) sections sections of the expansion of the expansion unitcryogenic unit and the and the cryogenic cooling sub-device, cooling sub-device, further further reducing reducing the the radiation radiation heatheat leaks leaksfromfrom room temperaturetotothese room temperature these components. components.

[0027] Preferably,

[0027] Preferably, the radiation the radiation shieldshield is thermally is thermally connectedconnected to the pre-cooling to the pre-cooling unit. unit.

[0028] Preferably,the

[0028] Preferably, theliquid liquidhydrogen hydrogentransfertransferpipeline pipelineconnecting connectingthe theliquefaction liquefactiondevice device and the and the liquid liquid hydrogen storage tank hydrogen storage tank is is aa vacuum-insulated dual-walledpipeline. vacuum-insulated dual-walled pipeline.

[0029] Preferably,the

[0029] Preferably, thecryogenic cryogenicliquefaction liquefactionconversion conversion unitisiscomposed unit composed of one of one or more or more

cryogenicliquefaction cryogenic liquefaction setssets arranged arranged in parallel, in parallel, each cryogenic each cryogenic liquefaction liquefaction set is composed set is composed

of one of one or or more cryogeniccooling more cryogenic coolingsub-devices sub-devicesarrangedarrangedininseries, series, and and each eachcryogenic cryogeniccooling cooling sub-device comprises sub-device comprisesa standard a standard refrigeration refrigeration unitunitandand an an ortho-para ortho-para hydrogen hydrogen converter converter

thermallyconnected thermally connected to ato a cold cold end ofendtheofstandard the standard refrigeration refrigeration unit. unit.

[0030] Furtherpreferably,

[0030] Further preferably,for foreach eachcryogenic cryogenicliquefaction liquefactionset, set, the the hydrogen hydrogenflow flowchannels channels of the of the ortho-para ortho-para hydrogen convertersare hydrogen converters aresequentially sequentiallyconnected connected in in seriesaccording series accordingtotothethe hydrogen hydrogen flow flow direction, direction, and and the cold the cold head temperatures head temperatures of the refrigeration of the standard standard refrigeration units or units or the temperatures the temperatures of of the the ortho-para ortho-para hydrogen convertersare hydrogen converters are sequentially sequentially reduced. reduced.

7

[0031] Furthermore,

[0031] Furthermore, in in thethe present present disclosure, disclosure, thethe cryogenic cryogenic liquefaction liquefaction conversion conversion unitunit

comprisesone comprises oneorormore more (denoted (denoted aswhere as m, m, where m≥1) cryogenic m>1) cryogenic liquefaction liquefaction sets. sets. When a When a plurality ofofcryogenic plurality cryogenic liquefaction liquefaction sets sets are employed, are employed, the plurality the plurality of cryogenic of cryogenic liquefaction liquefaction

sets are sets are connected connected in in parallel parallel totoeach each other. other.The The feed feed hydrogen fromthe hydrogen from thepre-cooling pre-coolingunitunitisis divided into divided into mmpaths, paths,each each connected connected to a to a respective respective cryogenic cryogenic liquefaction liquefaction set. Eachset. Each cryogenic liquefaction cryogenic liquefaction setset includes includes one one or or more (denoted as more (denoted as n, n, where n≥1)cryogenic where n>1) cryogeniccooling cooling sub-devices connected sub-devices connectedininseries. series.Each Eachcryogenic cryogenic cooling cooling sub-device sub-device comprises comprises a standard a standard

refrigeration unit refrigeration unitand and anan ortho-para ortho-para hydrogen converter. The hydrogen converter. Theortho-para ortho-parahydrogen hydrogen converter converter

is is installed at the installed at coldend the cold endofofthethestandard standard refrigeration refrigeration unit unit and comprises and comprises a refrigerant a refrigerant flow flow channelandand channel a hydrogen a hydrogen flow flow channel. channel. The refrigerant The refrigerant of the refrigeration of the standard standard refrigeration unit flows unit flows

directly within directly within the the refrigerant refrigerantflow flowchannel channel ofof the theortho-para ortho-para hydrogen converter, providing hydrogen converter, providing cooling for cooling for the the hydrogen hydrogen andandthe theortho-para ortho-parahydrogen hydrogen reaction.TheThe reaction. hydrogen hydrogen flowflow channel channel

of the of the ortho-para hydrogen ortho-para hydrogen converter converter is provided is provided with ortho-para with ortho-para hydrogen hydrogen catalyst tocatalyst catalyzeto catalyze

the ortho-para the ortho-para hydrogen reaction. hydrogen reaction.

[0032]

[0032] The The hydrogen hydrogen flowflow channels channels of theof ortho-para the ortho-para hydrogen hydrogen converters converters in theinplurality the plurality of (n) of (n) cryogenic coolingsub-devices cryogenic cooling sub-devicesarearesequentially sequentiallyconnected connected in series. in series. TheThe n standard n standard

refrigeration units refrigeration unitsoperate operateatatsuccessively successivelydecreasing decreasingtemperatures, temperatures,TTc,1>Tc,2> c,1>Tc,2> …>Tcn-1>Tc.n. >Tc,n-1>Tc,n. During actual operation, the cryogenic hydrogen from the pre-cooling unit, with a temperature During actual operation, the cryogenic hydrogen from the pre-cooling unit, with a temperature

of TpreC of TpreC and and aa para-hydrogen para-hydrogenconcentration concentration close close totothe theequilibrium equilibriumpara-hydrogen para-hydrogen concentration at concentration at the the pre-cooling temperatureTpreC, pre-cooling temperature TpreC, sequentially sequentially passes through the passes through the nn ortho- ortho- parahydrogen para hydrogen converters converters connected connected in series in series in eachincryogenic each cryogenic liquefaction liquefaction set. The hydrogen set. The hydrogen

is gradually is gradually cooled cooled inin the the hydrogen flowchannels hydrogen flow channelsofofthethen northo-para ortho-para hydrogen hydrogen converters converters

and undergoes and undergoesprogressive progressiveortho-para ortho-parahydrogen hydrogen conversion conversion withwith the the assistance assistance of the of the ortho- ortho-

para hydrogen para hydrogencatalyst, catalyst,reaching reachinga atemperature temperature of of TpreExpandand TpreExp a pressure a pressure of ppreExp of PpreExp before before

throttling, with throttling, witha apara-hydrogen para-hydrogen concentration exceeding95%. concentration exceeding 95%.The The design design hashas thethe following following

advantages: advantages:

1．The useofofaalarge 1. The use large number numberofofstandardized standardizedcryogenic cryogenic cooling cooling sub-devices sub-devices facilitates facilitates

massstandardized mass standardizedproduction productionand and installation, installation, resulting resulting in significantly in significantly equipment equipment cost cost

reduction; reduction;

2．Independent 2. operation Independent operation of of one one or or more more of the of the paralleled paralleled cryogenic cryogenic liquefaction liquefaction sets sets

allows for allows for aa wide wide range of capacity range of capacity adjustment withoutaffecting adjustment without affecting system systemenergy energyefficiency; efficiency; 3．The 3. seriesconnection The series connectionofofthe theplurality plurality of of cryogenic cryogenic cooling coolingsub-devices sub-devicesreduces reducesthe the heat exchange heat exchangetemperature temperature difference difference between between the the refrigerant refrigerant andand hydrogen hydrogen in each in each ortho- ortho-

para hydrogen para converter,improving hydrogen converter, improvingsystem system energy energy efficiency; efficiency;

4．The 4. designofofthetheortho-para The design ortho-para hydrogen hydrogen converter converter minimizes minimizes the transfer the heat heat transfer path path

betweenthe between therefrigerant refrigerant and andhydrogen hydrogen (separated (separated only only by one by one heat heat exchange exchange wall),wall), which which

reduces the reduces the heat heat exchange temperaturedifference exchange temperature differenceand andenhancing enhancing system system energy energy efficiency; efficiency;

5．The 5. independent The independent standard standard refrigeration refrigeration units units improve improve systemsystem stability; stability; even ifeven if

8 individual refrigeration units fail, only the liquefaction capacity will be affected, without individual refrigeration units fail, only the liquefaction capacity will be affected, without causing the causing the entire entire system system to to shut shut down; down;

6．The 6. independent The independent standard standard refrigeration refrigeration unitsunits can can be be maintained maintained and and replaced replaced separately, enhancing separately, maintenanceconvenience, enhancing maintenance convenience, and and reducing reducing thethe OPEX. OPEX.

[0033] Preferably,totoenhance

[0033] Preferably, enhancethetheheat heatexchange exchange efficiency efficiency within within thethe ortho-para ortho-para hydrogen hydrogen

converter, both converter, both the the refrigerant refrigerantflow flowchannel channel and and the the hydrogen hydrogen flowflow channel channelofofthethe ortho-para ortho-para hydrogen hydrogen converter converter are are provided provided with enhanced with enhanced heat transfer heat transfer structures,structures, suchThe such as fins. as inlet fins. The inlet andoutlet and outletofofthe thehydrogen hydrogenflow flow channel channel are provided are provided withof filters with filters of appropriate appropriate pore size topore size to

prevent ortho-para prevent ortho-para hydrogen hydrogencatalyst catalystparticles particles from fromentering enteringthe thepiping pipingsystem. system.TheThe ortho- ortho-

para hydrogen para catalyst within hydrogen catalyst within the the hydrogen flow channel hydrogen flow channelofof the the ortho-para ortho-para hydrogen converter hydrogen converter

canbebearranged can arranged in in various various configurations: configurations:

1．The ortho-parahydrogen 1. The ortho-para hydrogen catalystcompletely catalyst completely fillsthe fills theflow flowchannel: channel:TheThe advantage advantage

is that is that the the filling filling process is simple, process is simple,ensuring ensuring sufficient sufficient catalyst catalyst for for complete complete reaction; reaction;

2．The 2. ortho-parahydrogen The ortho-para hydrogen catalyst catalyst partiallyfills partially fills the the flow flow channel: channel: The Theadvantage advantageis is

that the filling process is simple as well, and as hydrogen flows, it lifts the catalyst particles that the filling process is simple as well, and as hydrogen flows, it lifts the catalyst particles

withinthe within theflow flowchannel, channel, enabling enabling thorough thorough contactcontact and and heat heat transfer transfer with the with the hydrogen, hydrogen, which which is conducive is conducive to to a complete a complete reaction; reaction;

3．The 3. ortho-parahydrogen The ortho-para hydrogen catalyst catalyst is is filledininsegments, filled segments, with with filtersofofappropriate filters appropriate pore size used to secure each segment of catalyst, reducing contamination from microparticles pore size used to secure each segment of catalyst, reducing contamination from microparticles

generated by generated by catalyst catalyst particle particlewear wear and and fragmentation; fragmentation;

4．The 4. ortho-parahydrogen The ortho-para hydrogen catalyst catalyst is is adhered adhered to to thesurface the surfaceofofthe theflow flowchannel channel andand

the surface of the enhanced heat transfer structures using adhesive: The advantage is low flow the surface of the enhanced heat transfer structures using adhesive: The advantage is low flow

resistanceand resistance andadequate adequate heatheat transfer; transfer;

[0034] Preferably,

[0034] Preferably, the standard the standard refrigeration refrigeration unit is unit is a regenerative a regenerative refrigerator, refrigerator, specifically specifically

including the including the Gifford-McMahon Gifford-McMahon (GM)(GM) refrigerator, refrigerator, Stirling Stirling refrigerator,Solvay refrigerator, Solvayrefrigerator, refrigerator, GM-type pulsetube GM-type pulse tube refrigerator,ororStirling-type refrigerator, Stirling-type pulse pulse tube tube refrigerator. refrigerator. The The advantages advantages ofof usingsuch using sucha aregenerative regenerative refrigerator refrigerator arefollows: are as as follows: 1．The regenerative 1. The regenerative refrigerators refrigerators offer offer considerable considerable coolingcooling efficiency efficiency in the in the temperaturerange temperature rangebetween betweenliquid liquidnitrogen nitrogenand andliquid liquidhydrogen; hydrogen; 2．The 2. corecomponents The core componentsof of thethe regenerative regenerative refrigeratorsare refrigerators arestructurally structurally simple and do simple and do not require not require high high precision precision manufacturing manufacturingororparticularly particularlyexpensive expensivematerials, materials,making making them them

particularly suitable particularly suitable for for large-scale large-scale mass massproduction, production, therefore therefore the cost the cost per standard per standard

refrigeration unit can be significantly reduced; refrigeration unit can be significantly reduced;

3．The 3. regenerative The regenerative refrigerators refrigerators are are quite quite reliable, reliable, with with the Gifford-McMahon the Gifford-McMahon

refrigerator, Solvay refrigerator, and GM-type pulse tube refrigerator offering a maintenance- refrigerator, Solvay refrigerator, and GM-type pulse tube refrigerator offering a maintenance-

free operating free operating period period (MFOP) exceeding (MFOP) exceeding 2 years,while 2 years, while theMFOP the MFOP of the of the Stirling Stirling refrigerator refrigerator

or Stirling-type or Stirling-typepulse pulsetube tube refrigerator refrigerator can can exceed exceed 5 years; 5 years;

9

4．The 4. regenerativerefrigerators The regenerative refrigeratorstypically typically utilize utilize piston piston expansion, whichprovides expansion, which providesa a substantial flow-rate substantial flow-rate and andconsiderable considerable cooling cooling capacity capacity during during the cool-down the cool-down process,process,

inherently enabling rapid inherently enabling rapidcool-down cool-down andand facilitating facilitating quick quick start-up start-up andand shutdown shutdown of theof the

system. system.

[0035]

[0035] The The expansion expansion unitunitcancan be be a single a single one, one, andandthethe hydrogen hydrogen pipelines pipelines from from m parallel m parallel

cryogenic liquefaction cryogenic liquefaction setssets converge converge and connect and connect to theof inlet to the inlet of the expansion the expansion unit, whileunit, the while the

outlet of outlet of the theexpansion expansion unitunit is connected is connected to thetoliquid the liquid hydrogenhydrogen productbyoutlet; product outlet; setting by up setting up

a common a common expansion expansion unitunit for for m parallel m parallel cryogenic cryogenic liquefaction liquefaction sets,sets, such such design design has thehas the advantageofof lower advantage lowercost.cost.

[0036] Preferably,m m

[0036] Preferably, expansion expansion unitsunits are are provided, provided, each each withinlet with its its inlet connected connected to theto the

hydrogenpipeline hydrogen pipelinefrom fromone one ofofthethem m parallelcryogenic parallel cryogenic liquefactionsets, liquefaction sets,and andthe theoutlets outlets of of all the all the expansion expansion units units converge converge and andthenthenconnect connecttotothe theliquid liquid hydrogen hydrogenproduct product outlet;byby outlet;

setting up setting upaaseparate separateexpansion expansion unitunit for for eacheach cryogenic cryogenic liquefaction liquefaction set, such set, suchimproves design design improves systemreliability, system reliability, and and independent independent controlcontrolofofthe theexpansion expansion units units alsoalso allows allows forfor system system

capacity adjustment capacity adjustment and andindependent independentmaintenance maintenance of of each each device. device.

[0037]

[0037] TheThe expansion expansion unit canunitbe can be a capillary a capillary tube, a tube, a throttle throttle valve, valve, or an expander. or an expander. Preferably, Preferably, the expansion the expansion unitunit is isan an adjustable adjustable throttle throttle valve valve with with a shut-off a shut-off function. function.

[0038]

[0038] As As a specific a specific preferred preferred solution, solution, the expansion the expansion units areunits are a plurality a plurality of throttle of valves throttle valves arranged inin parallel, arranged parallel, eacheach of of the the throttle throttle valvevalve is is connected connectedtotothe theplurality plurality ofof cryogenic cryogenic liquefactionsets liquefaction setsofofthe thecorresponding corresponding cryogenic cryogenic liquefaction liquefaction conversionconversion unit. unit.

[0039] Preferably,

[0039] Preferably, the product the product outlets outlets of theof the liquefaction liquefaction device aredevice are connected connected to a plurality to a plurality of (j, of (j,where j≥2)parallel where j>2) parallelliquid liquidhydrogen hydrogen storage storage tanks.tanks. Thepipeline The main main pipeline for liquid forhydrogen liquid hydrogen productsfrom products fromthe the liquefaction liquefaction systemsystem is divided is divided into jeach into j lines, lines, each connected connected to a respective to a respective liquid hydrogen liquid storage tank hydrogen storage tank through throughcryogenic cryogenicvalves. valves.The Theliquid liquidhydrogen hydrogenproduced produced by by thethe

liquefactiondevice liquefaction device is is stored stored sequentially sequentially in each in each tank,tank, and aand a full-filled full-filled liquid liquid hydrogen hydrogen storagestorage

tank can tank cantransfer transfer liquid liquid hydrogen hydrogen within within it to it to a liquid a liquid hydrogen hydrogen tanker/ship tanker/ship for further for further

transportation to transportation to the the endend customers customersofofliquid liquidhydrogen. hydrogen. WithWith thisthisdesign, design, by closing by closing the the

cryogenic valves, cryogenic valves, thethe liquid liquid hydrogen hydrogen storage storage tank that tank is that is undergoing undergoing transfer operations transfer operations can can be disconnected be disconnectedfrom fromthetheliquefaction liquefactionsystem,system, while while thethe liquid liquid hydrogen hydrogen produced produced by theby the

liquefaction system liquefaction system can canstill still be be stored stored in in other other liquid liquid hydrogen storage tanks, hydrogen storage tanks, ensuring ensuring the the continuity of continuity of liquid liquidhydrogen production and hydrogen production andstorage. storage.

[0040] Furtherpreferably,

[0040] Further preferably,the theliquid liquid hydrogen hydrogenstorage storagetank tankisis aa tank tank container. container.When When aa tank tank container container isisfull-filled full-filledwith withliquid liquidhydrogen, hydrogen, it canit can be transported be transported to the to the liquid liquid hydrogenhydrogen end end customers customers by by container container trailers/ships. trailers/ships. The transported The transported tank container tank container is thenwith is then replaced replaced a with a newempty new emptyone, one,which which is is connected connected to to thethe liquefactiondevice. liquefaction device.The The adoption adoption of of standardized standardized

tank containers tank containers eliminates eliminates the the need needfor fortransferring transferring liquid liquid hydrogen hydrogenfrom from stationaryliquid stationary liquid hydrogen hydrogen storage storage vessels vessels to liquid to liquid hydrogen hydrogen tankers/ships, tankers/ships, therebythe thereby reducing reducing boil-offthe loss boil-off loss during during thetheprocess. process.ForFor large-scale large-scale applications, applications, a combination a combination of numerous of numerous standardized standardized tank tank containers with containers with container container trailers/ships trailers/ships offers offersa acost cost advantage advantageover over aa combination combination of of semi- semi-

10 customizedstationary customized stationarystorage storage tanks tanks with with liquid liquid hydrogen tankers/ships. hydrogen tankers/ships.

[0041] During

[0041] During thethe transferofofthe transfer the liquid liquid hydrogen fromthe hydrogen from thestorage storagetanks, tanks, the the replacement of replacement of

the tank the tank containers, containers, oror long-term long-termstorage, storage,a certain a certainamount amount of theof liquid the liquid hydrogen hydrogen will will

vaporize,causing vaporize, causingan an increase increase in pressure in pressure withinwithin the hydrogen the liquid liquid hydrogen storage storage tanks. This tanks. will This will eventuallytrigger eventually triggerthethesafety safety reliefsystem, relief system, resulting resulting in hydrogen in hydrogen lossventing. loss via via venting. To re-liquefy To re-liquefy

the boil-offhydrogen the boil-off hydrogen fromfrom the liquid the liquid hydrogen hydrogen storage storage tanks, ittanks, it is preferable is preferable to connectto aconnect boil- a boil- off vapor off vaporreturn returnline linefrom fromthe the top top of liquid of the the liquid hydrogen hydrogen storage storage tanks to tanks one or to one more of or themore of the

liquefactiondevices. liquefaction devices. That That is,is, a top a top of of thethe liquid liquid hydrogen hydrogen storagestorage tank is tank is provided provided with a boil- with a boil-

off vapor return line, and the boil-off vapor return line is connected to a hydrogen pipeline in off vapor return line, and the boil-off vapor return line is connected to a hydrogen pipeline in

one ormore one or more of of thethe liquefaction liquefaction devices. devices.

[0042]

[0042] AsAs an an optimized optimized solution, solution, within within the the liquefaction liquefaction device, device, thethe boil-off boil-off vapor vapor return return

line isisconnected line connected to toaacryogenic cryogenic compressor compressor andand then then to to the the pipeline pipeline between the penultimate between the penultimate

(orderedaccording (ordered according to the to the hydrogen hydrogen flow direction) flow direction) and the and lastthe last cryogenic cryogenic cooling sub-devices cooling sub-devices

in one in one or or more morecryogenic cryogenic liquefaction liquefaction sets.TheThe sets. boil-off boil-off hydrogen hydrogen is compressed is compressed to high to high

pressure by pressure by the thecryogenic cryogeniccompressor compressor and and thenthen mixedmixed withincoming with the the incoming feed hydrogen, feed hydrogen,

enteringthe entering thefinal finalcryogenic cryogenic cooling cooling sub-device sub-device to be cooled to be cooled and liquefied. and liquefied.

[0043] Alternatively,

[0043] Alternatively, as another as another optimized optimized solution, solution, within the within the liquefaction liquefaction device, thedevice, boil- the boil-

off vapor off vaporreturn return line line is is connected connected to the tolow-pressure the low-pressure inlet of inlet of an ejector. an ejector. The high-pressure The high-pressure

inlet of inlet of the theejector ejectorisis connected connectedtotothe feed the feed hydrogen hydrogen pipeline pipeline from from thethe ortho-para ortho-para hydrogen hydrogen

converter in converter in thethe second second lastlast cryogenic cryogenic cooling cooling sub-device sub-device of of one one oror more cryogenic more cryogenic liquefactionsets. liquefaction sets.The The outlet outlet of of thethe ejector ejector is connected is connected to theto the ortho-para ortho-para hydrogenhydrogen converter converter

in the in last cryogenic the last cooling cryogenic cooling sub-device sub-device of theofcryogenic the cryogenic liquefaction liquefaction set. The set. Theutilizes ejector ejector utilizes a high-flow a high-flow rate,rate, high-pressurized high-pressurized feed feed hydrogen hydrogenstream streamasasthethemain main flow flow to to pump pump and and mix mix

with the with the low-flow low-flow rate, rate, low-pressurized boil-off hydrogen. low-pressurized boil-off hydrogen. The Thetwotwohydrogen hydrogen streams streams mixmix in in

the ejector the ejector andand then enter the then enter the last lastcryogenic cryogenic cooling cooling sub-device sub-device to to be be cooled cooledand andliquefied. liquefied. Compared Compared to to cryogenic cryogenic compressors, compressors, ejectors ejectors have have no moving no moving parts, parts, are cost-effective, are cost-effective, and and

offer high offer highreliability. reliability.

[0044]

[0044] The The compression compression unitunit is aiscompressor a compressor set composed set composed of a plurality of a plurality of compressors, of compressors,

and the and the plurality plurality of of compressors respectivelyprovide compressors respectively providecompression compression workwork for the for the cryogenic cryogenic

liquefactionconversion liquefaction conversion unit.unit.

[0045] Preferably,the

[0045] Preferably, thecompressor compressor unitcomprises unit comprises m*nm*n independent independent compression compression units,units, eacheach

compressionunit compression unitisisindividually individuallyconnected connected to to respective respective standard standard refrigeration refrigeration units. units. By By

adopting adopting this thistechnical technical solution, solution, it becomes it becomes easy easy to switch to switch each standard each standard refrigeration refrigeration unit on unit on or off. or off. The smaller compression The smaller compressionunits unitsarearemore more conducive conducive to large-scale to large-scale massmass production, production,

therebyreducing thereby reducing costs. costs.

[0046] Preferably,a ahydrogen

[0046] Preferably, hydrogen pipeline pipeline andand a cold a cold refrigerant refrigerant pipeline pipeline areare arranged arranged in in thethe

coldend cold endofofthe thestandard standard refrigeration refrigeration unit,unit, one one part part or all or of allthe of the hydrogen hydrogen pipeline pipeline is provided is provided

with an with an ortho-para ortho-para hydrogen hydrogen catalyst, catalyst, andand the the partpart oror all all ofof the the hydrogen hydrogenpipeline pipeline simultaneouslyforms simultaneously formsthe theortho-para ortho-parahydrogen hydrogen converter. converter.

11

[0047] Compared

[0047] Compared withwith the prior the prior art,art, thethe beneficial beneficial effectsofofthethepresent effects presentdisclosure disclosureare areasas follows: The follows: present disclosure The present disclosure achieves achieves hydrogen hydrogenliquefaction liquefactionthrough throughnumerous numerous refrigeration units refrigeration units connected connected ininseries seriesand andparallel parallelto toform form devices devices at different at different levels, levels,

effectively leveraging effectively the benefits leveraging the benefits of of large-scale large-scale standard standard refrigeration refrigeration unit unit production to production to

significantly reduce significantly reduce equipment costs. By equipment costs. controlling the By controlling the number ofdevices number of devicesand andrefrigeration refrigeration units activated at different levels, the present disclosure also enables a wide range of liquid units activated at different levels, the present disclosure also enables a wide range of liquid

hydrogen hydrogen production production capacity capacity adjustments. adjustments. Additionally, Additionally, utilizing utilizing a regenerative a regenerative refrigerator refrigerator

as the as the standard standardrefrigeration refrigeration unit unit allows allowsforforrapid rapidcool-down cool-downand and immediate immediate shutdown, shutdown,

endowingthe endowing thesystem system with with thethe advantage advantage of quick of quick startup startup and and shutdown. shutdown. TheseThese advantages advantages

makethe make thepresent presentdisclosure disclosureparticularly particularly suitable suitable for for using the renewable using the energysources renewable energy sourcestoto producegreen produce greenliquid liquid hydrogen. hydrogen.

BRIEF DESCRIPTION BRIEF DESCRIPTION OF OF THE THE DRAWINGS DRAWINGS

[0048] Fig. 11 is

[0048] Fig. is aa schematic schematic diagram diagram of of the the first firstembodiment embodiment of of aa modular modular hydrogen hydrogen liquefactionsystem liquefaction system according according topresent to the the present disclosure. disclosure.

[0049]

[0049] Fig.Fig.2 2isis aa schematic schematicdiagram diagramofofthe thefirst first embodiment embodiment ofofthe theliquefaction liquefaction system systeminin aa modularhydrogen modular hydrogen liquefactionsystem liquefaction system according according to to thethe presentdisclosure. present disclosure.

[0050]

[0050] Fig.Fig.3 3isisaa schematic schematicdiagram diagram of of thethesecond second embodiment embodiment of the of liquefaction the liquefaction system system

in aa modular in hydrogenliquefaction modular hydrogen liquefactionsystem systemaccording according toto thepresent the presentdisclosure. disclosure.

[0051]

[0051] Fig.Fig.4 4isisa aschematic schematic diagram diagram of the of the second second embodiment embodiment of a modular of a modular hydrogen hydrogen

liquefactionsystem liquefaction system according according to thetopresent the present disclosure. disclosure.

[0052]

[0052] Fig. 55 isis aa schematic Fig. schematic diagram diagram of first of the the first embodiment embodiment of the liquefaction of the liquefaction system in system in

the second the embodiment second embodiment of of a modular a modular hydrogen hydrogen liquefaction liquefaction system system according according to thetopresent the present disclosure. disclosure.

[0053]

[0053] Fig. 66 isisa aschematic Fig. schematic diagram diagram of of the the second second embodiment embodiment ofof theliquefaction the liquefactionsystem system in the in thesecond second embodiment embodiment ofofaamodularmodularhydrogen hydrogen liquefaction liquefaction system system according according to to thepresent the present disclosure. disclosure.

[0054]

[0054] The The corresponding corresponding relationship relationship between between reference reference signs signs and and component component names names is as is as

follows: follows:

[0055]

[0055] 1, 1, hydrogen hydrogen gas source; gas source; 2, liquefaction 2, liquefaction system; system; 2.1~2.k, 2.1~2.k, liquefaction liquefaction device; 3, device; liquid 3, liquid

hydrogen hydrogen storage storage tanktankset; set; 3.1~3.j, 3.1~3.j, liquid liquid hydrogen hydrogen storage storage tank; tank;

[0056]

[0056] 21, 21,pre-cooling pre-cooling unit;unit; 22, 22, cryogenic cryogenic liquefaction liquefaction conversion conversion unit; 22.1.~22.m, unit; 22.1.22.m,

cryogenicliquefaction cryogenic liquefactionset; set; 23, 23,expansion expansion unit; unit; 24,24, liquid liquid hydrogen hydrogen product product outlet; outlet; 25, 25, compressionunit; compression unit;26, 26,vacuum-insulated vacuum-insulated cold-box; cold-box; 27, 27, radiation radiation shield; shield; 28, 28, boil-off boil-off vapor vapor

return line; return line;31. 31.cryogenic cryogenic valve; valve; 32, 32, gas return gas return controlcontrol valve; valve; 211, pre-cooling 211, pre-cooling cold source;cold source; 212,pre-cooling 212, pre-cooling heatheat exchanger; exchanger; 212a/b, 212a/b, first-stage/second-stage first-stage/second-stage pre-cooling pre-cooling heat exchanger; heat exchanger;

213, purifier; 213, purifier; 213a/b, 213a/b, cryogenic cryogenicpurification purificationadsorber; adsorber;214, 214, pre-cooling-stage pre-cooling-stage ortho-para ortho-para

hydrogenconverter; hydrogen converter;215, 215,cooling cooling heatheat exchanger exchanger for the for the radiation radiation shield; shield; 221,221, cryogenic cryogenic

12 cooling sub-device; 222, standard refrigeration unit; 223, ortho-para hydrogen converter; 231, cooling sub-device; 222, standard refrigeration unit; 223, ortho-para hydrogen converter; 231, throttle valve; 251, compressor set; 252, high-pressure gas supply line; and 253, low-pressure throttle valve; 251, compressor set; 252, high-pressure gas supply line; and 253, low-pressure gas return gas returnline. line.

DETAILED DESCRIPTION DETAILED DESCRIPTION OF OF THE THE EMBODIMENTS EMBODIMENTS

[0057]

[0057] ToTo make make the the objectives, objectives, technical technical solutions,and solutions, andadvantages advantagesof of thethe embodiments embodiments of of the present the present disclosure disclosure clearer, clearer, the the following providesaafurther following provides further detailed detailed description description of of the the embodimentsofofthe embodiments thepresent present disclosure disclosure with with reference reference to to the the accompanying drawings. accompanying drawings. However, the However, the described described embodiments embodimentsare are only only part part of of the the embodiments embodimentsofofthe thepresent present disclosure, not disclosure, all of not all them. Based of them. Basedon on thethe embodiments embodiments of theof the present present disclosure, disclosure, other other embodiments embodiments derived derived from from non-creative non-creative efforts efforts by by a person a person skilled skilled in in thethe artartfall fall within withinthe the scopeofofprotection scope protection of of thethe present present disclosure. disclosure.

[0058]

[0058] Embodiment Embodiment 1: 1:

[0059]

[0059] AsAs shown shown in Fig. in Fig. 1, 1, a modular a modular hydrogen hydrogen liquefaction liquefaction system system comprises comprises a hydrogen a hydrogen

gas source gas source 1, 1, aa liquefaction liquefaction system system 22 and and a a liquid liquid hydrogen storage tank hydrogen storage tank set set 3, 3, the the hydrogen hydrogen

gas source gas source1,1,the theliquefaction liquefactionsystem system 2 and 2 and the the liquid liquid hydrogen hydrogen storage storage tank3 are tank set set 3 are sequentially sequentially connected throughpipelines. connected through pipelines.

[0060]

[0060] The The liquefactionsystem liquefaction system 2 comprises 2 comprises oneone or or more more (k≥1) (k>1) liquefaction liquefaction devices devices (2.1~2.k) (2.1~2.k)

connectedinin parallel. connected parallel. The The liquefaction liquefaction devices devices 2.1~2.k 2.1~2.k areare standardized standardized skid-mounted skid-mounted units, units, integrating components integrating components suchsuch as pre-cooling, as pre-cooling, liquefaction, liquefaction, and conversion and conversion components,components, intermediate piping, intermediate piping, and andcontrol controlvalves valvesintointoa single a single entity,adopting entity, adopting standard standard container container

dimensions.Each dimensions. Eachdevice device cancan operate operate independently, independently, cooling cooling and and liquefying liquefying hydrogenhydrogen at a at a

certain flow-rate certain flow-rate and completingthe and completing theortho-para ortho-parahydrogen hydrogen conversion. conversion. TheThe liquidliquid hydrogen hydrogen

storage tank storage tank setset 33comprises comprisestwotwo or more or more (j>2)(j≥2) liquid liquid hydrogen hydrogen storagestorage tanks (3.1~3.j) tanks (3.1~3.j)

connected connected in in parallel; parallel; andand the the liquid liquid hydrogen hydrogen storagestorage tanks 3.1~3.j tanks 3.1~3.j are tank are tank containers. containers.

[0061]

[0061] The The pipelinesfrom pipelines from thetheliquid liquidhydrogen hydrogen product product outlets2424ofofeach outlets eachliquefaction liquefaction device device 2.1~2.k in 2.1~2.k in the the liquefaction liquefaction system system 22 are are converged convergedinto intomajor majorpipeline pipelineforforliquid liquidhydrogen hydrogen product, which product, whichisisthen thendivided divided into into j pipelines,each j pipelines, each connecting connecting to the to the respective respective liquid liquid

hydrogen hydrogen storage storage tankstanks 3.1~3.j. 3.1~3.j. The pipelines The pipelines betweenbetween the liquefaction the liquefaction system 2 and system 2 and the liquid the liquid

hydrogenstorage hydrogen storagetankstanks3.1~3.j 3.1~3.jare are vacuum-insulated vacuum-insulateddual-walled dual-walled cryogenic cryogenic liquid liquid hydrogen hydrogen

pipelines. pipelines.

[0062]

[0062] The The working working principle principle of of hydrogen hydrogen liquefaction liquefaction using using thisthisembodiment embodiment is as is as follows: follows:

[0063]

[0063] The The feed feed hydrogen hydrogen fromfrom the hydrogen the hydrogen gas source gas source 1, at an1, ambient at an ambient temperaturetemperature of of T (263~313 K)K)and amb (263~313 Tamb anda pressure a pressureof of Psupply (10~26 P supply (10~26 bar),bar), andand withwith a apara-hydrogen para-hydrogen concentration of concentration of approximately approximately25%, 25%,isisdivided dividedintointokkpathways. pathways.Through Through each each pathway, pathway, the the

hydrogenenters hydrogen entersintointothetherespective respective liquefaction liquefaction devices devices 2.1~2.k 2.1~2.k withinwithin the liquefaction the liquefaction

system2,2, where system whereitit isis cooled, cooled, liquefied, liquefied, and undergoesthe and undergoes theortho-para ortho-parahydrogen hydrogen conversion conversion

process. Subsequently, process. Subsequently,the the liquefied liquefied hydrogen hydrogenflows flowsintointothe theliquid liquidhydrogen hydrogen storage storage tanks tanks

13

3.1~3.j for 3.1~3.j for storage. storage. The productliquid The product liquidhydrogen hydrogen flowing flowing out out of liquefaction of the the liquefaction devices devices

2.1~2.k has 2.1~2.k hasa apressure pressureofofPstore pstore (1~6 (1~6bar), bar), aatemperature temperatureofofTproduct, Tproduct, and andaapara-hydrogen para-hydrogen concentration ofof>95%. concentration ≥95%.The The mentioned mentioned productproduct liquid hydrogen liquid hydrogen is subcooled, is subcooled, i.e. the i.e. the temperatureofofthe temperature theproduct product liquid liquid hydrogen hydrogen is lower is lower than than the saturation the saturation temperature temperature of of hydrogen atatitsits hydrogen pressure (Tproduct pressure By<Tcontrolling sat(pstore)). By controlling the opening the and opening and closing closing of theof the cryogenicvalves cryogenic valves31,31, the the product product liquidliquid hydrogen hydrogen is sequentially is sequentially filled filled into eachinto each of the of the liquid liquid

hydrogenstorage hydrogen storage tanks tanks 3.1~3.j. 3.1~3.j. The The tank containers tank containers filled filled with hydrogen with liquid liquid hydrogen are are transported to transported to the the liquid liquid hydrogen hydrogen end-users end-users by container by container trailers, trailers, and and the empty the empty tank tank

containers spots containers spots are are loaded loadedwith withnew new empty empty containers, containers, which which are connected are then then connected to the to the liquefaction system. liquefaction system.

[0064]

[0064] TheThe liquidhydrogen liquid hydrogen production production capacity capacity of of thetheentire entiremodular modularhydrogen hydrogen liquefaction liquefaction

systemcan system canbebeadjusted adjustedwithin withina awide widerange range by by activating activating differentnumbers different numbersof of liquefaction liquefaction

devices.Since devices. Sinceeach each liquefaction liquefaction device device operates operates independently, independently, theenergy the overall overall energy efficiency efficiency

of the of the system systemdoes does notnot significantly significantly change change due to due to capacity capacity adjustments. adjustments.

[0065]

[0065] Embodiment Embodiment 2: 2:

[0066]

[0066] AsAs shown shown in Fig. in Fig. 2, the 2, the liquefaction liquefaction device device in the in the modular modular hydrogen hydrogen liquefaction liquefaction

systemcomprises system comprisesa pre-cooling a pre-cooling unit unit 21,21, a cryogenic a cryogenic liquefaction liquefaction conversion conversion unitan22, unit 22, an expansionunit expansion unit 23, 23, aa liquid liquid hydrogen productoutlet hydrogen product outlet 24, 24, and and aa compression compressionunit unit25. 25.The Thepre- pre- cooling unit 21 cooling unit 21 comprises comprises aa pre-cooling pre-cooling cold cold source source 211, 211, aa pre-cooling pre-cooling heat heat exchanger 212,aa exchanger 212,

purifier 213, purifier 213, and and aa pre-cooling-stage pre-cooling-stage ortho-para ortho-parahydrogen hydrogen converter converter 214. 214. TheThe pre-cooling- pre-cooling-

stage stage ortho-para ortho-para hydrogen converter214 hydrogen converter 214isisprovided providedwithwithortho-para ortho-parahydrogen hydrogen catalyst.TheThe catalyst.

pre-cooling heat pre-cooling heat exchanger exchanger212 212is isprovided provided with with a hydrogen a hydrogen flowflow channel channel for hydrogen for hydrogen to to passthrough pass through andand a pre-cooling a pre-cooling refrigerant refrigerant flow channel flow channel for the for the pre-cooling pre-cooling refrigerantrefrigerant to pass to pass through. The through. cryogenic liquefaction The cryogenic liquefaction conversion conversionunit unit2222comprises comprisesone one oror more more (m≥1) (m>1) independentcryogenic independent cryogenicliquefaction liquefactionsets sets22.1~22.m 22.1~22.m connected connected in parallel. in parallel. EachEach cryogenic cryogenic

liquefaction liquefaction set setcomprises comprises one one or or more (n≥1) independent more (n>1) independentcryogenic cryogeniccooling coolingsub-devices sub-devices 221221 connectedin connected in series. series. TheThe cryogenic cryogenic cooling sub-device 221 cooling sub-device 221comprises comprisesa astandard standardrefrigeration refrigeration unit 222 unit and an 222 and an ortho-para ortho-parahydrogen hydrogenconverter converter 223. 223. TheThe ortho-para ortho-para hydrogen hydrogen converter converter 223 223

comprisesaarefrigerant comprises refrigerant flowflow channel channeland anda ahydrogen hydrogen flowflow channel, channel, and and the the hydrogen hydrogen flow flow

channelisisprovided channel provided withwith the the ortho-para ortho-para hydrogen hydrogen catalyst catalyst inside. inside.

[0067]

[0067] The The hydrogen hydrogen gas source gas source 1, the1,hydrogen the hydrogen flow channel flow channel of the pre-cooling of the pre-cooling heat heat exchanger212, exchanger 212,the the purifier purifier 213,213, and and the the pre-cooling-stage pre-cooling-stage ortho-para ortho-parahydrogen converter 214 hydrogen converter 214 are connected are connected in in sequence sequencethroughthrough pipelinesorordirectly pipelines directlythrough throughsealed sealedinterfaces. interfaces.TheThepre- pre- cooling cold cooling cold source sourceisis connected connectedtotothethecold coldendend inletof ofthethepre-cooling inlet pre-cooling refrigerantflow refrigerant flow channel ofof the channel the pre-cooling pre-coolingheat heatexchanger exchanger through through a pipeline. a pipeline. TheThe pre-cooling pre-cooling refrigerant refrigerant

flows throughthe flows through thepre-cooling pre-coolingrefrigerant refrigerantflowflowchannel channel of ofthethe pre-cooling pre-cooling heat heat exchanger, exchanger,

providing cooling providing coolingfor for the the hydrogen hydrogenflowing flowing through through thethe hydrogen hydrogen flowflow channel channel of theofpre- the pre- cooling heatexchanger, cooling heat exchanger, the the purifier, purifier, and and the the pre-cooling-stage pre-cooling-stage ortho-para ortho-para hydrogen hydrogen converter. converter.

Theoutlet The outletpipeline pipeline of of the the pre-cooling-stage pre-cooling-stage ortho-para ortho-para hydrogen hydrogen converterconverter 214 is 214 is divided divided into into

14 mpathways, m pathways,which which areare connected connected in parallel in parallel to to m m cryogenic cryogenic liquefaction liquefaction sets22.1~22.m. sets22.1~22.m. In In each cryogenic liquefaction set, n ortho-para hydrogen converters 223 are connected in series each cryogenic liquefaction set, n ortho-para hydrogen converters 223 are connected in series through pipelines. through pipelines. Each Eachortho-para ortho-parahydrogen hydrogen converter converter 223223 is connected is connected to the to the coldcold end end of of the standard the standardrefrigeration refrigeration unitunit 222.222. The refrigeration The refrigeration in the standard in the standard refrigeration refrigeration unit 222 unit 222 flows throughthetherefrigerant flows through refrigerantflow flow channel channel of the of ortho-para the ortho-para hydrogen hydrogen converterconverter 223, 223, providing cooling. providing cooling.TheTheoutlet outletpipelines pipelinesofofthethem parallel m parallel cryogenic cryogenic liquefaction liquefaction setssets are are connected connected to to the the expansion expansion unit unit 23,the 23, and andoutlet the outlet of theof the expansion expansion unit unit 23 is 23 is connected connected to the to the liquid hydrogen liquid productoutlet hydrogen product outlet 24. 24. The compressionunit The compression unit2525isis connected connectedtotothe the m*n m*nstandard standard refrigeration units 222 through gas supply lines, driving the standard refrigeration units 222 refrigeration units 222 through gas supply lines, driving the standard refrigeration units 222 to provide to providecryogenic cryogenic refrigeration. refrigeration.

[0068]

[0068] The The working working principle principle of of hydrogen hydrogen liquefaction liquefaction using using thisembodiment this embodiment is as is as follows: follows:

[0069]

[0069] The The feed feed hydrogen hydrogen fromfrom the hydrogen the hydrogen gas source gas source 1, ambient 1, at an at an ambient temperature temperature of of T amb (263~313 Tamb (263~313 K)K) anda apressure and pressureofofPsupply Psupply (10~26 bar), containing (10~26 bar), approximately25% containing approximately 25% para- para-

hydrogen, hydrogen, firstenters first entersthethe hydrogen hydrogen flow flow channel channel of the pre-cooling of the pre-cooling heat 212. heat exchanger exchanger It is 212. It is pre-cooled to pre-cooled to aa pre-cooling pre-cooling temperature temperature ofof TTpreC, preC, which whichranges rangesbetween between 60 60 to to150 150 KK depending depending

on the on thedifferent differentforms formsof of thethe pre-cooling pre-cooling cold cold source source and theand the pre-cooling pre-cooling refrigerant. refrigerant. The pre- The pre-

cooled hydrogen cooled hydrogenthen thenenters entersthe the purifier purifier 213 213 to to remove the residual remove the residual gaseous impurity such gaseous impurity suchas as water, CO , N , as well as solid particles. Subsequently, it enters the pre-cooling-stage ortho- water, CO2, 2N2, as 2 well as solid particles. Subsequently, it enters the pre-cooling-stage ortho-

para hydrogen para converte214, hydrogen converte 214,where wherethe theortho-para ortho-parahydrogen hydrogen conversion conversion is is completed completed withwith thethe

aid of aid of the theortho-para ortho-para hydrogen hydrogen catalyst catalyst in the in the reactor, reactor, and it isandre-cooled it is re-cooled to the pre-cooling to the pre-cooling

temperatureTpreC. temperature TpreC. The Theamount amount of catalyst of catalyst in the in the pre-cooling-stage pre-cooling-stage ortho-para ortho-para hydrogen hydrogen

converte converte 214 214 should should be sufficient be sufficient to ensure to ensure that thethathydrogen the hydrogen leaving leaving the the pre-cooling pre-cooling unit 21 unit 21 is is asas close close as as possible possible to to equilibrium equilibrium hydrogen hydrogen (i.e.,(i.e., the the para-hydrogen concentrationisis as para-hydrogen concentration as close asas possible close possibleto tothethe equilibrium equilibrium para-hydrogen para-hydrogen concentration concentration at the pre-cooling at the pre-cooling

temperature temperature TpreC).TheThe Tprec). hydrogen hydrogen leaving leaving the pre-cooling the pre-cooling unit 21 is unit 21 is into divided divided intoeach m paths, m paths, each of them of thementering enteringoneone of of thethe m parallel m parallel cryogenic cryogenic liquefaction liquefaction sets 22.1~22.m. sets 22.1~22.m. In the cryogenic In the cryogenic

liquefaction conversionunit liquefaction conversion unit22,22,each each of ofthethe n standard n standard refrigeration refrigeration unitsunits 222each 222 in in each cryogenic liquefaction setsetoperates cryogenic liquefaction operates at successively at successively decreasing decreasing temperaturestemperatures TTc,1>Tc,2> c,1>Tc,2> … ...>T>Tcn-1>Tc c,n-1>Tc,n. The hydrogenpasses The hydrogen passesthrough throughn nseries-connected series-connected ortho-para ortho-para hydrogenconverters hydrogen converters223; 223;each each ortho-para ortho-para hydrogen hydrogen converter converter 223 223 is connected is connected to the to cold the cold end ofofthe end thestandard standardrefrigeration refrigerationunit unit222, 222, andand the the cooling cooling generated generated by the by the standard standard

refrigeration unit refrigeration unit222222 isistransferred transferred to to thethehydrogen hydrogenflowing flowingininthethehydrogen hydrogen flowflow channel channel ofof

the ortho-para the hydrogenconverter ortho-para hydrogen converter223 223 through through thethe flow flow of its of its refrigerantininthe refrigerant therefrigerant refrigerant flow channel. The flow channel. Thehydrogen hydrogenisisgradually graduallycooled cooledinin the the hydrogen hydrogenflow flowchannels channelsofofthe thennortho- ortho- para hydrogen para hydrogenconverters, converters,and andwith with thetheaidaidof ofthethe ortho-para ortho-para hydrogen hydrogen catalyst, catalyst, a gradual a gradual

ortho-para hydrogen ortho-para hydrogenconversion conversion is achieved, is achieved, reaching reaching the pre-expansion the pre-expansion temperature temperature of of T preExpandaa pressure TpreExpand pressureofofPpreExp ppreExp(PpreExp (ppreExp ==PPsupply supply –where Δp, where Ap is theΔppressure is the pressure drop of hydrogen drop of hydrogen

passing through passing throughthe the pre-cooling pre-coolingunitunit 21 21andandthethecryogenic cryogenicliquefaction liquefactionconversion conversion unit22), unit 22), and aa para-hydrogen and concentrationover para-hydrogen concentration overthanthan95%. 95%. At At thisthispoint, point,the the hydrogen hydrogenisissubcooled. subcooled.

15

[0070] The

[0070] The hydrogen, hydrogen, cooled cooled to atosubcooled a subcooled state state in the in the cryogenic cryogenic liquefaction liquefaction conversion conversion

unit 22, unit 22, enters enters the the expansion unit 23. expansion unit 23. Depending Dependingonon thethe differentchoices different choicesofofthetheexpansion expansion unit, the unit, the pressure reduction process pressure reduction processofofhydrogen hydrogenin in thethe expansion expansion unitunit 23Pproduct 23 to to pproduct maymay

undergoisentropic undergo isentropicexpansion, expansion,isenthalpic isenthalpicexpansion, expansion, or or a polytropic a polytropic process process somewhere somewhere

betweenthe between thetwo. two.The The temperature temperature of the of the hydrogen hydrogen may decrease may decrease (the expansion (the expansion tends totends to isentropic)ororincrease isentropic) increase (the (the expansion expansion tendstends to isenthalpic). to isenthalpic). The temperature The temperature of the hydrogen of the hydrogen

that leaves that leavesthe theexpansion expansion unitunit 23Tproduct, 23 is is Tproduct , thus thus the the hydrogen hydrogen remainsremains subcooledsubcooled liquid withliquid with

a certain a degreeofofsubcooling. certain degree subcooling. ThisThis ensures ensures that thethatliquid the liquid hydrogen hydrogen remains inremains a liquidinform a liquid form during its transfer to the liquid hydrogen storage tanks 3.1~3.j. After expansion, the subcooled during its transfer to the liquid hydrogen storage tanks 3.1~3.j. After expansion, the subcooled

liquid hydrogen liquid hydrogen product product is finally is finally delivered delivered through through the hydrogen the liquid liquid hydrogen product product outlet outlet to the to the

downstream downstream pipelineand pipeline andultimately ultimatelystored storedininthe theliquid liquid hydrogen hydrogenstorage storagetanks. tanks.

[0071]

[0071] InIn themodular the modular hydrogen hydrogen liquefaction liquefaction system, system, the standard the standard refrigeration refrigeration unit unit 222 222

included inin the included thecryogenic cryogenicliquefaction liquefactionconversion conversion unitunit 22 is 22a isregenerative a regenerative refrigerator, refrigerator,

specifically which specifically which cancan be beaa Gifford-McMahon Gifford-McMahon refrigerator, refrigerator, a Stirling a Stirling refrigerator,aaSolvay refrigerator, Solvay refrigerator, aa GM-type refrigerator, GM-type pulse pulse tube tube refrigerator, refrigerator, or a Stirling-type or a Stirling-type pulse pulse tube tube refrigerator. refrigerator. The The compression compression unitunit 25connected 25 is is connected to allto all standard standard refrigeration refrigeration units 222units 222a through through a gas supply gas supply

line and is used to drive the regenerative refrigerator, providing cooling capacity to the ortho- line and is used to drive the regenerative refrigerator, providing cooling capacity to the ortho-

para hydrogen para hydrogenconverter converter 223223 to achieve to achieve hydrogen hydrogen coolingcooling and theand the ortho-para ortho-para hydrogen hydrogen

conversionreaction. conversion reaction.

[0072]

[0072] The The compression compression unitunit 25 can 25 can employemploy an integrated an integrated compressor compressor set or set or a plurality a plurality of of independentcompressors, independent compressors,each eachwith withitsitsown owncompression compression function, function, or or it itcan canbebea alarge largesingle single compressor. Preferably, compressor. Preferably, an integrated compressor an integrated compressor set set oror aa plurality plurality of of independent independent compressors compressors areare usedused for for easeease of control of control and toand to ensure ensure overalloverall energy efficiency. energy efficiency. In particular, In particular,

whenititisisnecessary when necessary to to shut shut down down one one or or cryogenic more more cryogenic liquefaction liquefaction sets, using sets, using an integrated an integrated

compressorset compressor set allows allows forfor the the shutdown shutdown of of the the corresponding compressorset corresponding compressor setwithout withoutaffecting affecting the energy the energyefficiency efficiency of of thethe entire entire compression compression unit. unit.

[0073]

[0073] Embodiment Embodiment 3: 3:

[0074]

[0074] AsAs shown shown in Fig. in Fig. 3, in3, in thethe modular modular hydrogen hydrogen liquefaction liquefaction system, system, a morea more detaileddetailed schematicofof the schematic the liquefaction liquefaction systemsystem22isis illustrated, illustrated, where where the the pre-cooling pre-cooling coldcold source 211 source 211

adoptsaaturbo-Brayton adopts turbo-Brayton cyclecycle refrigeration refrigeration system, system, the standard the standard refrigeration refrigeration unit 222 unit 222 employs employs

a Gifford-McMahon a Gifford-McMahonrefrigerator, refrigerator, the the compression compression unit unit 2525consists consists ofof a aplurality plurality ofof independent compressor independent compressor units, units, andand the the expansion expansion unit unit 23 utilizes 23 utilizes a plurality a plurality of parallel of parallel

throttling control throttling control valves valves as as expansion elements.The expansion elements. Thesystem system is is thermally thermally insulated insulated using using a a

vacuum-insulatedcold-box vacuum-insulated cold-box 2626andand a radiationshield a radiation shield27. 27.TheThedifference differencefrom from Embodiment Embodiment 2 2 lies in lies in the the following: following:

[0075]

[0075] The The pre-cooling pre-cooling heatheat exchanger exchanger 212 is212 is a series-connected a series-connected two-stage two-stage pre-cooling pre-cooling

structure, comprising structure, comprising aa first-stage first-stage pre-cooling pre-cooling heat heat exchanger 212aand exchanger 212a anda asecond-stage second-stagepre- pre- cooling heat exchanger cooling heat exchanger212b. 212b. TheThe cryogenic cryogenic adsorption adsorption purifier purifier 213 is213composed is composed of two of two

parallel cryogenic parallel cryogenic adsorption adsorptionpurifiers, purifiers,thethecryogenic cryogenic adsorption adsorption purifier213a purifier213a and the and the

16 16 cryogenic adsorption cryogenic adsorptionpurifier213b purifier213b.

[0076] Meanwhile,

[0076] Meanwhile, in the in the embodiment, embodiment, the pre-cooling the pre-cooling systemsystem 21 adopts 21 adopts a nitrogen a nitrogen turbo-turbo-

Braytonrefrigeration Brayton refrigeration cycle cycle as the as the pre-cooling pre-cooling cold cold sourcesource 211,includes 211, which which includes a driving amotor driving motor 2111, aa turbo-compressor 2111, turbo-compressor2112, 2112, a water a water cooler cooler 2113, 2113, a cryogenic a cryogenic turbo-expander turbo-expander 2114, a2114, a

connectingshaft connecting shaft2115, 2115,andand a cooling a cooling heatheat exchanger exchanger for theforradiation the radiation shield shield 215. The215. The aforementioned components aforementioned components areare connected connected in inthethe following following sequence: sequence: thethe high-pressure high-pressure outlet outlet

of the of the turbo-compressor turbo-compressor 2112,2112, the water the water coolerthe2113, cooler 2113, inlet the inlet of the of the pre-cooling pre-cooling refrigerant refrigerant

in-flow channel in-flow channel at at thethe hothot endend of the of the first-stage first-stage pre-cooling pre-cooling heat exchanger heat exchanger 212a, the212a, outletthe of outlet of

the pre-cooling refrigerant in-flow channel at the cold end of the first-stage pre-cooling heat the pre-cooling refrigerant in-flow channel at the cold end of the first-stage pre-cooling heat

exchanger exchanger 212a, 212a, the the inletinlet of the of the pre-cooling pre-cooling refrigerant refrigerant in-flowin-flow channel channel at the hotat theofhot end the end of the

second-stagepre-cooling second-stage pre-coolingheatheatexchanger exchanger 212b, 212b, thethe outlet outlet of of thethe pre-cooling pre-cooling refrigerantin-in- refrigerant

flow channel flow channelatat the the cold cold end end ofof the the second-stage second-stagepre-cooling pre-coolingheat heatexchanger exchanger 212b, 212b, thethe inlet inlet

of the of the cryogenic turbo-expander2114, cryogenic turbo-expander 2114,the theoutlet outletofofthe the cryogenic cryogenicturbo-expander turbo-expander 2114, 2114, thethe

coolingheat cooling heatexchanger exchanger forradiation for the the radiation shield shield 215, the215, inletthe of inlet of the pre-cooling the pre-cooling refrigerant refrigerant

return-flow channel return-flow channel atat the the cold cold end end of of the the second-stage second-stage pre-cooling pre-cooling heat heat exchanger 212b,the exchanger 212b, the outlet of outlet of the the pre-cooling pre-cooling refrigerant refrigerant return-flow return-flow channel channel at at the the hot hot end end of of the the second-stage second-stage

pre-cooling heat exchanger 212b, the inlet of the pre-cooling refrigerant return-flow channel pre-cooling heat exchanger 212b, the inlet of the pre-cooling refrigerant return-flow channel

at the at the cold endofofthe cold end thefirst-stage first-stagepre-cooling pre-cooling heat heat exchanger exchanger 212a, 212a, the outlet the outlet of the of the pre-cooling pre-cooling

refrigerant return-flow refrigerant return-flow channel channel at at the the hot hot end end of of the the first-stage first-stage pre-cooling pre-cooling heatheat exchanger exchanger

212a, and 212a, andfinally finally back backtotothethelow-pressure low-pressureinlet inletofofthetheturbo-compressor turbo-compressor 2112, 2112, forming forming a a closed loop. closed loop. The turbo-compressor 2112 The turbo-compressor 2112and andthethecryogenic cryogenicturbo-expander turbo-expander2114 2114 areare mechanicallycoupled mechanically coupledthrough throughthethe connecting connecting shaft shaft 2115, 2115, and and the the connecting connecting shaftshaft 2115 2115 is is providedwith provided withaa driving driving motor motor2111. 2111.

[0077]

[0077] InInthetheembodiment, embodiment, thethe working working principle principle of of thethe pre-cooling pre-cooling coldcold source source 211211 using using a a

turbo-Braytoncycle turbo-Brayton cyclerefrigeration refrigerationsystem system is asis follows: as follows: The pre-cooling The pre-cooling refrigerant refrigerant is is compressedtotohigh compressed highpressure pressurebyby thethe turbo-compressor turbo-compressor 2112,2112, and heat and the the heat generated generated duringduring

compressionisisremoved compression removed by by thethe water water cooler cooler 2113 2113 and and the pre-cooling the pre-cooling refrigerant refrigerant is cooled is cooled

downtoto around down aroundambient ambienttemperature. temperature.After After compression compressionand andcooling, cooling,the thepre-cooling pre-cooling refrigerant enters refrigerant enters thethefirst-stage first-stage pre-cooling pre-cooling heat heatexchanger exchanger 212a 212a and the second-stage and the second-stagepre- pre- cooling heatexchanger cooling heat exchanger 212b212b successively, successively, where itwhere it is by is cooled cooled by the returning the returning cold refrigerant cold refrigerant

to approximately to 100~120 approximately 100~120 K. Subsequently, Subsequently, the pre-cooling the pre-cooling refrigerant refrigerant entersenters the cryogenic the cryogenic

turbo-expander turbo-expander 2114 2114 forfor expansion expansion refrigeration. refrigeration. Depending Depending on theon the refrigerant refrigerant and theand the

pressureafter pressure afterexpansion, expansion, the the temperature temperature of theof the pre-cooling pre-cooling refrigerant refrigerant can ultimately can ultimately drop to drop to around 80~100K.K.TheThe around 80~100 cryogenic, cryogenic, low-pressure low-pressure pre-cooling pre-cooling refrigerantthen refrigerant thenreturns returns successivelytotothethecooling successively coolingheatheat exchanger exchanger for thefor the radiation radiation shield shield 215, the215, the second-stage second-stage pre- pre- cooling heat cooling heat exchanger exchanger212b, 212b,andandthe thefirst-stage first-stage pre-cooling pre-cooling heatheat exchanger exchanger212a 212atotoprecool precool the incoming the incominghigh-pressure high-pressurerefrigerant refrigerantand andfeed feedhydrogen, hydrogen, warming warming up toup to around around ambient ambient temperaturebefore temperature beforeexiting exitingthethe first-stagepre-cooling first-stage pre-cooling heatheat exchanger exchanger 212afinally 212a and and finally returning to returning to the the low-pressure low-pressure inletinlet of of the the turbo-compressor turbo-compressor2112. 2112.TheThe driving driving motor motor 21112111

17 provides the provides the main driving force main driving force to to drive drivethe theturbo-compressor turbo-compressor 2112, 2112, while while the theexpansion expansion work work of the of the cryogenic cryogenicturbo-expander turbo-expander 2114 2114 is recovered is recovered through through the connecting the connecting shaft shaft 2115 2115 to to provide auxiliary provide auxiliary driving driving force force for forthe theturbo-compressor turbo-compressor 2112. 2112.

[0078]

[0078] The The embodiment embodiment provides provides a morea detailed more detailed description description of the of the pre-cooling pre-cooling process process

flow for flow for hydrogen. Thehydrogen hydrogen. The hydrogengas gassource source1 1isis connected connectedtoto the the hydrogen flowchannel hydrogen flow channelinlet inlet of the of hot end the hot endofofthe thefirst-stage first-stagepre-cooling pre-cooling heat heat exchanger exchanger 212a. 212a. The incoming The incoming feed hydrogen feed hydrogen

passes through passes through the the hydrogen flowchannels hydrogen flow channelsofofthe thefirst-stage first-stage pre-cooling pre-cooling heat heat exchanger exchanger 212a 212a

and the and the second-stage second-stagepre-cooling pre-coolingheatheatexchanger exchanger212b 212bin in sequence, sequence, andand then then connects connects to the to the

parallel cryogenic parallel adsorptionpurifiers cryogenic adsorption purifiers213a 213a andand 213b. 213b. Here,Here, the cryogenic the cryogenic adsorption adsorption

purifiers 213a purifiers and 213b 213a and 213bconstitute constituteaatypical typical temperature temperatureswing swingadsorption adsorption (TSA) (TSA) unit. unit. TheThe

two purifiers are switched through valves and alternately connected to the pipeline, while the two purifiers are switched through valves and alternately connected to the pipeline, while the

purifier not purifier connectedtotothethepipeline not connected pipelineis ispurged purgedand and heated heated by clean by clean inertgashotforgas for inert hot

regeneration.After regeneration. After being being connected connected in parallel, in parallel, the cryogenic the cryogenic purification purification adsorbersadsorbers 213a and 213a and

213bare 213b areconnected connected to the to the inlet inlet of the of the hot of hot end endtheofsecond-stage the second-stage pre-cooling pre-cooling heat exchanger heat exchanger

212bthrough 212b throughpipelines pipelinesand andenter enterthethepre-cooling-stage pre-cooling-stage ortho-para ortho-para hydrogen hydrogen converter converter 214 214

located in located in the the second-stage pre-coolingheat second-stage pre-cooling heatexchanger exchanger212b. 212b.In In thisembodiment, this embodiment, the the pre-pre-

cooling-stage ortho-para cooling-stage ortho-para hydrogen hydrogenconverter converter214 214isisananisothermal isothermalreactor reactorcoupled coupledwithin withinthe the second-stage pre-cooling second-stage pre-cooling heat heat exchanger exchanger 212b, 212b, where whereparticles catalyst catalystare particles filled in arethefilled heat in the heat

exchange exchange channels channels of the of the heatheat exchanger exchanger to achieve to achieve the ortho-para the ortho-para hydrogenreaction hydrogen catalytic catalytic reaction while exchanging while exchangingheat. heat.This Thistypetypeofofisothermal isothermalreactor reactorfeatures features highhighreaction reaction efficiency efficiency andand lowirreversible low irreversiblelosses. losses.After Afterleaving leavingthethe pre-cooling-stage pre-cooling-stage ortho-para ortho-para hydrogen hydrogen converter converter 214, 214, the feed the feedhydrogen hydrogen is connected is connected to theto the of inlet inlet theof the ortho-para first first ortho-para hydrogenhydrogen converter 223 converter in 223 in each parallel each parallel cryogenic cryogenic liquefaction liquefaction set22.1~22.m. set22.1~22.m.

[0079]

[0079] InInthe theembodiment, embodiment, the cold the cold end ofendtheof the standard standard refrigeration refrigeration unit 222,unitwhich 222, which employsa aGifford-McMahon employs Gifford-McMahon (GM) refrigerator, (GM) refrigerator, is connected is connected to the to the ortho-para ortho-para hydrogenhydrogen

converter 223. converter 223. When When theGMGM the refrigerator refrigerator is is in in operation,its operation, itsrefrigerant refrigerant expands expandsatat the the cold cold end and end andalternately alternately flowsflows through throughthe therefrigerant refrigerant flow flowchannels channelsininthe theortho-para ortho-parahydrogen hydrogen converter 223, converter 223, providing providingthe thenecessary necessarycooling coolingforforthetheortho-para ortho-parahydrogen hydrogen reaction reaction of of thethe

hydrogenflowing hydrogen flowingthrough through thethehydrogen hydrogen flowflow channels channels of the of the ortho-para ortho-para hydrogen hydrogen converter converter

223. With 223. Witheach eachpasspassthrough througha aortho-para ortho-parahydrogen hydrogen converter converter 223, 223, thethe hydrogen hydrogen is gradually is gradually

cooled and cooled andthetheortho-para ortho-parahydrogen hydrogen reaction reaction is is completed. completed. AfterAfter passing passing through through n series- n series-

connected ortho-para connected ortho-para hydrogen converters 223, hydrogen converters the hydrogen 223, the hydrogen reachesreaches aa pre-expansion pre-expansion temperature temperature of of TpreExpand TpreExpand a pressure a pressure of ppreExp of PpreExp (where(where PpreExpppreExp = P-supply = Psupply Ap, – Δp, and Ap and Δp represents represents

the pressure the pressure drop along the drop along the path path as as the the hydrogen hydrogenflows flowsthrough through thethe pre-cooling pre-cooling unit2121 unit andand the cryogenic the liquefaction conversion cryogenic liquefaction conversion unitunit 22), 22), with with aapara-hydrogen concentration over para-hydrogen concentration over than than 95%.AtAtthis 95%. thispoint, point, thethe hydrogen hydrogen is inisa in a subcooled subcooled state. state.

[0080]

[0080] InIn theembodiment, the embodiment, thethe compression compression unitunit 25 25 consists consists ofofm*nm*n independently independently operating operating

compressorunits compressor units251. 251. Each Eachcompressor compressor unit251 unit 251isisconnected connectedtotothe theGifford-McMahon Gifford-McMahon (GM)(GM)

refrigerator of refrigerator of each each standard standard refrigeration refrigeration unitunit222222 via via aa high-pressure high-pressure gas gas supply line 252 supply line 252

18 and aa low-pressure and low-pressuregas gasreturn returnline line 253, 253, serving servingtoto drive drive the the GM GM refrigerator.The refrigerator. Thedesign designofof independent compressor independent compressor units units 251 251 facilitates facilitates large-scale large-scale and and batchbatch production, production, therebythereby reducing the reducing the cost cost of of the the compression compressionunit. unit.Additionally, Additionally,thetheindependent independentoperation operation of of each each compressor unit compressor unit 251 251 enables enables the the independent independent start-up start-up and and shutdown shutdown of of each each standard standard refrigerationunit refrigeration unit222, 222,allowing allowing the the system system to adjust to adjust operating operating conditions conditions over over a wider a wider range range andenhancing and enhancing overall overall reliability. reliability.

[0081]

[0081] TheThe embodiment embodiment provides provides a morea more detailed detailed description description of the of the expansion expansion unit unit 23: 23: The The

expansion expansion unitunit2323comprises comprises m independent m independent adjustable adjustable throttle throttle valves valves 231 with231 with cutoff cutoff

capability. The capability. The hydrogen fromthe hydrogen from thefinal final ortho-para ortho-para hydrogen hydrogenconverter converter223223 in in each each of of them the m paralleled cryogenic paralleled liquefaction sets cryogenic liquefaction sets (22.1~22.m) (22.1~22.m) is is connected connected toto one one ofof the the m independent m independent

throttle valves throttle valves 231. 231. The The m mstreams streamsofofhydrogen hydrogen undergo undergo isenthalpic isenthalpic throttlingexpansion throttling expansion in in

the mmthrottle the throttlevalves valves 231, 231, reducing reducing the pressure the pressure from ptopreExp from PpreExp to pproduct Pproduct and slightly and slightly increasing increasing

the temperature the temperaturefromfromTpreExp TpreExptoto Tproduct. Tproduct. The The throttled throttled hydrogen remainsasasa aliquid hydrogen remains liquidwith witha a certain degree certain degree ofof subcooling. subcooling. After After the the mmstreams streamsofofthrottled throttled hydrogen hydrogenconverge converge into into one,one, theyare they areconnected connected to the to the liquid liquid hydrogen hydrogen productproduct interface interface 24. 24.

[0082]

[0082] ToTo reduce reduce heat heat leakage leakage fromfrom the the environment environment to thetocryogenic the cryogenic components components of the of the

system, the system, the embodiment alsoemploys embodiment also employs a vacuum-insulated a vacuum-insulated cold-box cold-box 26 aand 26 and a radiation radiation shield shield

27 for system insulation. The radiation shield 27, the pre-cooling unit 21, the expansion unit 27 for system insulation. The radiation shield 27, the pre-cooling unit 21, the expansion unit

23, and 23, andthe thecryogenic cryogenic portions portions of theof the cryogenic cryogenic cooling cooling sub-device sub-device (including(including the cold fingers the cold fingers

of the of the standard standardrefrigeration refrigeration units units andand the the ortho-para ortho-para hydrogen hydrogen converters) converters) are installed are installed inside inside the vacuum-insulated the vacuum-insulated cold-box cold-box26. 26.TheThe innerportion inner portionofofthethevacuum-insulated vacuum-insulated cold-box cold-box 26 26is is

evacuatedtoto minimize evacuated minimizeconvective convective andand conductive conductive heatheat leakage leakage from from the environment. the environment. The The radiationshield radiation shield2727isismade made of aofthin, a thin, thermally thermally conductive conductive metalwith metal shell shell with a polished a polished surface surface that provides that provideshighhigh reflectivity. reflectivity. It It isisthermally thermally connected connected to thetocooling the cooling heat exchanger heat exchanger for the for the radiationshield radiation shield215215andand is cooled is cooled to thetopre-cooling the pre-cooling temperature temperature TpreC. The Tradiation preC. Theshield radiation shield enclosesthe encloses thelowest lowest temperature temperature portions portions of theof the expansion expansion unit and unit and the cryogenic the cryogenic cooling sub- cooling sub- device, further device, further reducing reducingradiative radiativeheat heatleakage leakage fromfrom the ambient the ambient temperature temperature to theseto these

components. components.

[0083] Embodiment4:

[0083] Embodiment 4:

[0084]

[0084] AsAs shown shown in Fig. in Fig. 4, a 4,modular a modular hydrogen hydrogen liquefaction liquefaction system system employingemploying a boil-off a boil-off vapor return vapor return line line toto recover recover and andreliquefy reliquefy boil-off boil-off hydrogen. hydrogen.DuringDuringtransfer transfer(move(move liquid liquid

hydrogenfrom hydrogen from a stationarystorage a stationary storage tank tank into into transport transport vehicles vehicles suchsuch as as tankers tankers or ships), or ships),

replacementofofthe replacement the tank tank containers, containers, or or long-term storage in long-term storage in the the liquid liquid hydrogen storage tank hydrogen storage tank group 3, group 3, part part of of the the liquid liquid hydrogen evaporates,causing hydrogen evaporates, causingananpressure pressure increasing increasing within within thethe

liquid hydrogen liquid hydrogen storage storage tanks. tanks. This This will ultimately will ultimately trigger trigger the safetytherelief safetysystem, relief resulting system, resulting in in hydrogen loss hydrogen loss viavia venting. venting. In In thisthis embodiment, embodiment, a boil-off a boil-off vapor line vapor return returnis line used is toused to recover recover

the boil-off the boil-off hydrogen hydrogen from fromthe theliquid liquid hydrogen hydrogenstorage storagetanktankwith withexcessively excessively highhigh pressure pressure

due to due to flash flash evaporation evaporationand andreturn returnitittotooneoneofofthetheliquefaction liquefactiondevices devices (any (any oneone of theof the liquefactiondevices liquefaction devices 2.1~2.k) 2.1~2.k) in thein liquefaction the liquefaction systemsystem 2 for re-liquefaction. 2 for re-liquefaction. The difference The difference

19 betweenthis between this embodiment embodimentandand embodiment embodiment 2 lies2 in liesthein inclusion the inclusion of a of a boil-off boil-off vapor vapor return return line 28 and a gas return control valve 32. The boil-off vapor return line is led out from the top line 28 and a gas return control valve 32. The boil-off vapor return line is led out from the top of each of eachliquid liquidhydrogen hydrogen storage storage tank,tank, passespasses through through the gas the gascontrol return return valve control32, valve 32, and then and then jj lines linesfrom from various various liquid liquidhydrogen hydrogen storage storage tanks tanks converge converge intointo one one line, line,which which is isconnected connected to one to oneofofthe theliquefaction liquefaction devices devices in the in the liquefaction liquefaction systemsystem 2. 2.

[0085] Taking

[0085] Taking thethe returntotothe return theliquefaction liquefaction device device 2.1 2.1 asas an an example, the working example, the principle working principle

of the of the embodiment embodiment is is as as follows: follows: When When the pressure the pressure in the in liquid the liquid hydrogen hydrogen storagestorage tank tank

exceeds exceeds thethesetsetvalue value preV,high,set, the PreV,high,set, the cryogenic valve3131 cryogenic valve closes closes and and the the gas return gas return control control valve valve

32 opens, 32 opens, allowing allowingthe the boil-off boil-off hydrogen in the hydrogen in the liquid liquid hydrogen storage tank hydrogen storage tank to to flow flow back backtoto the liquefaction the liquefaction device device 2.1 2.1 through the boil-off through the boil-off vapor return line vapor return line 28. 28. The The boil-off boil-off hydrogen hydrogen

returning to the liquefaction device 2.1 is then reliquefied, and its working principle will be returning to the liquefaction device 2.1 is then reliquefied, and its working principle will be

described in described in detail detail in inEmbodiments Embodiments 5 5 and6.6.AsAsthetheboil-off and boil-offhydrogen hydrogen continues continues to to flow flow outout

of the of the liquid liquid hydrogen storage tank, hydrogen storage tank, the the pressure inside the pressure inside the tank tank gradually gradually decreases. decreases. When When

the pressure the pressurefalls fallsbelow belowthethe setset value value preV,low,set, the PreV,low,set, the cryogenic valve cryogenic valve 31 31 opens opens and and thereturn the gas gas return control control valve 32 closes, valve 32 closes, stopping stopping the the return return of of gas gas to to the the liquid liquid hydrogen storagetank hydrogen storage tankand and allowingitittotocontinue allowing continue receiving receiving liquid liquid hydrogen hydrogen productsproducts from the from the liquefaction liquefaction system 2. system 2.

[0086] Embodiment5:

[0086] Embodiment 5:

[0087]

[0087] AsAs shown shown in Fig.in Fig. 5, a5,more a more detailed detailed schematic schematic of theofliquefaction the liquefaction systemsystem 2 in a 2 in a

modular modular hydrogen hydrogen liquefaction liquefaction systemsystem that employs that employs a boil-offa vapor boil-off vapor return linereturn line to to recover andrecover and

reliquefy boil-off reliquefy boil-off hydrogen hydrogen isispresented. presented.The The difference difference fromfrom Embodiment Embodiment 3 lies 3 in lies the in the

inclusionofofa aboil-off inclusion boil-offvapor vapor return return lineline 28 anand 28 and an ejector ejector 291 in 291 this in this embodiment. embodiment. The boil- The boil-

off vapor off vaporreturn return line line 28 28 is connected is connected to theto the low-pressure low-pressure inlet of inlet of the291, the ejector ejector while 291, the while the

high-pressure high-pressure inletof of inlet thethe ejector ejector 291291 is connected is connected to theto the hydrogen hydrogen flowoutlet flow channel channel of theoutlet of the ortho-para hydrogen ortho-para hydrogenconverter converter223 223ininthe thepenultimate penultimatecryogenic cryogeniccooling coolingsub-device sub-device 221221(1.n- (1.n-

1) 1) of of the the cryogenic liquefaction set cryogenic liquefaction set 22.1 22.1 (although (although it it could could also also be be any any one one of of the the modules modules from thecryogenic from the cryogenic liquefaction liquefaction set 22.2~22.m). set 22.2~22.m). Theofoutlet The outlet of the291 the ejector ejector 291 is to is connected connected to the hydrogen the hydrogenflow flow channel channel inletinlet of the of the ortho-para ortho-para hydrogen hydrogen converter converter 223 in 223 in the final the final

cryogenic coolingsub-device cryogenic cooling sub-device(1.n) 221(1.n) of theofcryogenic the cryogenic liquefaction liquefaction set 22.1.set The 22.1.ejector The ejector utilizes aahigh utilizes highflow flowrate,rate, high-pressurized high-pressurized feed feed hydrogen hydrogen stream stream asas the theprimary primary flow flow toto pump pump

the low the flowrate, low flow rate, low-pressurized boil-off hydrogen. low-pressurized boil-off hydrogen. The Thetwotwohydrogen hydrogen streams streams mix mix in thein the ejector ejector before before entering entering the the final final ortho-para ortho-para hydrogen converter223, hydrogen converter 223,where wherethey theyarearecooled cooled andliquefied. and liquefied.

[0088] Embodiment6:

[0088] Embodiment 6:

[0089]

[0089] AsAs shown shown in Fig. in Fig. 6, 6, a detailedschematic a detailed schematic of of an an alternativetechnical alternative technicalsolution solutionfor for the the liquefaction system liquefaction system 2 in2 in a modular a modular hydrogen hydrogen liquefaction liquefaction system system that thata employs employs a boil-off vapor boil-off vapor

return line return line to recover and to recover andreliquefy reliquefyboil-off boil-offhydrogen hydrogen is is presented. presented. TheThe difference difference fromfrom

Embodiment Embodiment 5 liesininthe 5 lies thereplacement replacementofofthe theejector ejector 291 291withwithaacryogenic cryogeniccompressor compressor 292292 in in

this Embodiment. this Embodiment. The The boil-offvapor boil-off vaporreturn returnlineline2828isis connected connectedtotothe thelow-pressure low-pressureinlet inletofof the cryogenic the compressor292, cryogenic compressor 292, while while thethe high-pressure high-pressure outlet outlet of of thethe cryogenic cryogenic compressor compressor

20

292 is 292 is connected connectedtotothe the hydrogen hydrogenflow flow channel channel outlet outlet of of theortho-para the ortho-para hydrogen hydrogen converter converter

223 in 223 in the the penultimate penultimate cryogenic cooling sub-device cryogenic cooling sub-device221(1.n-1) 221(1.n-1)ofofthe the cryogenic cryogenicliquefaction liquefaction set 22.1. set 22.1.After Afterthe thefeed feedhydrogen hydrogen and and the the compressed boil-off hydrogen compressed boil-off hydrogenconverge, converge,they theyenter enter the hydrogen the flowchannel hydrogen flow channel of of theortho-para the ortho-parahydrogen hydrogen converter converter 223 223 in the in the final final cryogenic cryogenic

cooling sub-device 221(1.n) of the cryogenic liquefaction set 22.1, where they are cooled and cooling sub-device 221 (1.n) of the cryogenic liquefaction set 22.1, where they are cooled and

liquefied. liquefied.

21

Claims (12)

CLAIMS 16 Mar 2026 What is claimed is:

1. A modular hydrogen liquefaction system, comprising: a plurality of liquefaction devices arranged in parallel, wherein the liquefaction device comprises a hydrogen inlet and a product outlet, the hydrogen inlet is connected to a hydrogen gas source, and the product outlet is connected to a plurality of liquid hydrogen storage tanks that are connected in parallel; each liquefaction device comprises an integrated structure, and 2023277401

the integrated structure is used for hydrogen cooling, liquefaction, and completing ortho-para hydrogen conversion, and is arranged to start-up and shut-down independently; characterized in that:

the cryogenic liquefaction conversion unit is composed of a plurality of cryogenic liquefaction sets arranged in parallel, each cryogenic liquefaction set is composed of a plurality of cryogenic cooling sub-devices arranged in series, and each cryogenic cooling sub-device comprises a standard refrigeration unit and an ortho-para hydrogen converter thermally connected to a cold end of the standard refrigeration unit;

for each cryogenic liquefaction set, the hydrogen flow channels of the ortho-para hydrogen converters are sequentially connected in series according to the hydrogen flow direction, and the cold head temperatures of the standard refrigeration units or the temperatures of the ortho-para hydrogen converters are sequentially reduced.

2. The modular hydrogen liquefaction system according to claim 1, wherein the liquefaction device comprises:

a pre-cooling unit for pre-cooling hydrogen;

a cryogenic liquefaction conversion unit for liquefying pre-cooled hydrogen and converting the pre-cooled hydrogen to liquid hydrogen and performing ortho-para hydrogen conversion;

an expansion unit for reducing pressure of the hydrogen after cryogenic liquefaction and ortho-para hydrogen conversion, wherein an outlet of the expansion unit is connected to the liquid hydrogen storage tank; and

a compression unit for providing compression works to the cryogenic liquefaction conversion unit.

3. The modular hydrogen liquefaction system according to claim 2, wherein the pre-cooling unit comprises: a pre-cooling heat exchanger; 16 Mar 2026 a pre-cooling cold source for providing cooling for the pre-cooling heat exchanger; and a purifier and a pre-cooling-stage ortho-para hydrogen converter that are sequentially connected to a hydrogen flow channel of the pre-cooling heat exchanger.

4. The modular hydrogen liquefaction system according to claim 3, wherein the 2023277401

pre-cooling cold source is provided by the following pre-cooling circulation system:

a turbo-compressor for compressing a pre-cooling refrigerant to high pressure;

a driving motor for driving the turbo-compressor;

a water cooler for cooling a high-pressurized gas output from the turbo- compressor;

a cryogenic turbo-expander for expanding and cooling the pre-cooling refrigerant output from an in-flow channel of the pre-cooling heat exchanger; and

a hydrogen flow channel, the in-flow channel for the pre-cooling refrigerant and a return-flow channel for the pre-cooling refrigerant are arranged in the pre-cooling heat exchanger; wherein an inlet of the in-flow channel for the pre-cooling refrigerant is connected to an outlet of the water cooler, an outlet of the in-flow channel for the pre- cooling refrigerant is connected to an inlet of the cryogenic turbo-expander, an inlet of the return-flow channel for the pre-cooling refrigerant is connected to an outlet of the cryogenic turbo-expander, and an outlet of the return-flow channel for the pre-cooling refrigerant is connected to an inlet of the turbo-compressor.

5. The modular hydrogen liquefaction system according to claim 4, wherein the turbo-compressor recovers expansion work generated by the cryogenic turbo-expander through a connecting shaft connected between the turbo-compressor and the cryogenic turbo-expander.

6. The modular hydrogen liquefaction system according to claim 2, wherein the liquefaction device further comprises a vacuum-insulated cold-box and a radiation shield, and the radiation shield is thermally connected to the pre-cooling unit; the expansion unit and the lowest temperature portion of the cryogenic liquefaction conversion unit are arranged in the radiation shield; and the radiation shield, the cryogenic portion of the pre-cooling unit and the cryogenic portion of the cryogenic liquefaction conversion unit are arranged in the vacuum-insulated cold-box.

7. The modular hydrogen liquefaction system according to claim 1, wherein the 16 Mar 2026

liquid hydrogen storage tank is a tank container.

8. The modular hydrogen liquefaction system according to claim 1, wherein a top of the liquid hydrogen storage tank is provided with a boil-oR vapor return line, and the boil-oR vapor return line is connected to a hydrogen pipeline in the plurality of the liquefaction devices.

9. The modular hydrogen liquefaction system according to claim 1, wherein a top of 2023277401

the liquid hydrogen storage tank is provided with a boil-oR vapor return line, and the boil-oR vapor return line is connected to a hydrogen pipeline in the plurality of the liquefaction devices;

the modular hydrogen liquefaction system further comprises a cryogenic compressor, wherein an inlet of the cryogenic compressor is connected to the boil-oR vapor return line, and an outlet of the cryogenic compressor is connected to a pipeline between the last and the penultimate cryogenic cooling sub-devices in the plurality of cryogenic liquefaction sets;

or, the modular hydrogen liquefaction system further comprises an ejector, wherein a low-pressure inlet of the ejector is connected to the boil-oR vapor return line, a high-pressure inlet of the ejector is connected to an outlet pipeline of the penultimate cryogenic cooling sub-device in the plurality of cryogenic liquefaction sets, and an outlet of the ejector is connected to an inlet pipeline of the last cryogenic cooling sub- device in the corresponding cryogenic liquefaction set.

10. The modular hydrogen liquefaction system according to claim 2, wherein the compression unit is a compressor set composed of a plurality of compressors, and the plurality of compressors respectively provide compression work for the cryogenic liquefaction conversion unit.

11. The modular hydrogen liquefaction system according to claim 1, wherein the expansion unit is a plurality of throttle valves arranged in parallel, and each throttle valve is respectively connected to a corresponding outlet of the cryogenic liquefaction set.

12. The modular hydrogen liquefaction system according to claim 1, wherein a hydrogen pipeline and a cold refrigerant pipeline are arranged in the cold end of the standard refrigeration unit, one part or all of the hydrogen pipeline is provided with an

ortho-para hydrogen catalyst, and the part or all of the hydrogen pipeline 16 Mar 2026

simultaneously forms the ortho-para hydrogen converter. 2023277401