long term zbo(zero-boil-off) liquid hydrogen storage tanks · long term zbo lh2 storage tank –...

Florida Universities Hydrogen Review 2005Florida Solar Energy Center November 1-4, 2005

Long Term ZBO LH2 Storage Tank – Jong Baik – FSEC

Long Term ZBO(Zero-boil-off) Liquid Hydrogen Storage Tanks

Task 2. Hydrogen Storage Systems

Jong BaikHydrogen R&D Division, Florida Solar Energy Center

Start Date =January 2003Planned Completion = December 2006



Research Goals and Objectives

• To develop a long-term ZBO (zero-boil-off) LH2 storage system combining densified liquid hydrogen and passive/active cooling technologies.– Development of a 150 L capacity densified liquid hydrogen test facility

which is capable of liquefying, densifying hydrogen through a GM cryocooler and unique heat pipe design.

– Development of vapor cooled shield(VCS) with inline para-to-orthohydrogen converter to minimize boil-off loss from LH2 storage tank.

– Development of a Joule-Thompson expansion system to increase densification rate in the densifier, and to expand boil-off gas in the VCS of storage tank.



Relevance to Current State-of-the-Art• On-board hydrogen fuel storage for transportation : DOE, BMW, GM, Honda,

Linde etc.

Relevance to NASANASA GRC is interested in long term airborne hydrogen storage, transmission or distribution systems applied to LEAP (low emission alternative power) and HALE ROA (High altitude long endurance remotely operated aircrafts) Programs. LH2 is one of candidates where H2 is consumed rather than regenerated in the aircraft applications.LH2 tank systems are expected to provide airborne LH2 storage for up to 30 days duration by more than 1,000 Lbs of LH2 (~450 kg, 1,700 gal) at altitudes as high as 70,000 ft. Durable, light weight, high gravimetric energy density, high thermal control performance LH2storage/feed systems are required.



Budget, Schedule and Deliverables

12 3 6 9 12 3 6 9 12 3 6 9 12 3 6 9 12

Identify initial test strategy

Thermal analysis and system design

System fabrication and installation

Preliminary LN2 test

Preliminary LH2 test

Field facility preparation

O-P H2 converter design and test

Vapor cooled shield design and test

Pressurization and transfer test

2003 2004 2005 2006

J-T device design and test

Computational thermal analysis

Fuel cell backup power integration



Anticipated Technology End Use

• Long term airborne hydrogen storage, transmission or distribution systems applied to LEAP (low emission alternative power) and HALE ROA (High altitude long endurance remotely operated aircrafts) Programs.

• On-board hydrogen fuel storage for transportation• Low loss cryo-propellant storage system (1-3%/month) in Low Earth Orbit (LEO)

mission• ZBO system for Long term exploration mission (2 year+) to eliminate the need

for oversized tanks and extra propellant. Each pound of propellant tank mass saved is directly tradable for payload mass.

• Cryogenic Fluid Management (CFM) plays important role in exploration systems for Earth-to-Orbit Transportation, manned missions to the Moon and Mars, Planetary Exploration, and In-Situ Resource Utilization (ISRU).

• Infrared and x-ray astronomy, biological sciences, and fundamental investigations into the origins of our universe.



Densified liquid hydrogen system• Densified LH2, which is ~6% denser than normal boiling point LH2

– more hydrogen fuel can be stored in the same tank volume. As a result, airborne time can be increased.

• Densified hydrogen has lower sensible heat and higher latent heat – longer storage time is expected before evaporation.

179205.1105.9~ 319159575.1216

12 ↑2.2 ↑15.3 ↓> 5.3% ↓5.3% ↓5.6% ↑∆

167202.9121.2~ 337168571.1120

(hr)(MJ)(MJ)(W)(gal)(m3/kg)(K)

Storage timeLatent heat, m*hfgSensible heat, m*hf1Heat lossTank volumeρT

For m=1000 lb of liquid hydrogen fuel,

1Heat loss per volume is assumed to 0.2 W/gal (=8W/150L)



Hydrogen liquefaction and ZBO storage test facility at FSEC



ZBO (zero-boil-off) LH2 storage system

Passive coolingPassive cooling• combination of VCS (vapor-cooled

radiation shields) and in-line para-to-ortho converter can minimize boil-off losses from LH2 storage tank.

Active CoolingActive Cooling• Integration of a Joule-Thompson

expansion device in the hydrogen densifier to increase densification rate, and to expand boil-off gas to vapor cooled shield in the storage tank.

To minimize or to completely eliminate boilTo minimize or to completely eliminate boil--off losses from LH2 storage tankoff losses from LH2 storage tank

and maximize airborne time with single storage filling, itand maximize airborne time with single storage filling, it’’s essential to s essential to

employ both employ both passive and active cooling techniquespassive and active cooling techniques..



Vapor-cooled Radiation Shield (VCS)

with para-ortho converter

with VCS

LH2

loss ambient VCSQ Q Q= −& & &

without VCS

loss ambientQ Q=& &

Outer wall inner tank

lossQ&ambientQ&

VCSQ&

LH2

Outer wall VCS inner tank

ambientQ& LH2

Outer wall VCS & P- O converter inner tank

loss ambientQ Q=& &

46%

54%100%

100%

loss lossQ Q′ <& &

VCSQ ′&

with VCS + P- O converter

loss lossQ Q′ <& & 54%

100%

lossQ&

lossQ ′&

VCSQ ′&ambientQ&

ambientQ&

ambientQ&

lossQ&

VCSQ&300K

17K

Innervessel

outervessel

T

xVapor cooled shield

w/o VCS

w/ VCS

w/ VCS + p-o converter

1slope

Slope ~ heat leak

LH2, 99.9% Para- H2

Filled with para- ortho catalyst(iron, nickel, copper supported metal transition catalyst)

Vapor cooled shield (VCS)To application

Inner vessel

outer vessel

Evaporated 20K 99.9% Para- H2 cold gas

(ex) 300K, 25% Para- H2



LH2 Boil-off Test

0

5

10

15

20

25

30

35

-12 0 12 24 36 48

Pres

sure

(PSI

A)

Time (hr)

8 hr 8.5 hr7 hr

cryocooler off

atm

0

20

40

60

80

100

120

140

-12 0 12 24 36 48

TopUpperMiddleLowerBottomCryocooler

T (K

)Time (hr)

Energy conservation of Storage TankEnergy conservation of Storage Tank

( )

for consant & ,

, 1

leak

leak

leak

dU Qdt

dPor Qdt

dh T P dPV Qdt m dt

=

= +

&

&

&

0 1 2 3 4 5 6 717

18

19

20

21

22

23

24

Time [hr]

T[K]

TT



LH2 Boil-off Estimation

0 1 2 3 4 5 6 75

10

15

20

25

30

Time [hr]

P [p

sia]

PSIAPSIA

0 1 2 3 4 5 6 70.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

Time [hr]

Qua

lity

[-]

xx

0 1 2 3 4 5 6 72.8

3

3.2

3.4

3.6

3.8

4

Time[hr]

V liq

uid

[gal

]

VliquidVliquid

0 1 2 3 4 5 6 70

50

100

150

200

250

Time [hr]

AccumulatedHeatleak[kJ]



Refrigeration Effect of Para-ortho Conversion

0 50 100 150 200 250 3000

50

100

150

200

250

300

350

400

T [K]

RefrigerationEffect[kJ/kg]

20.6527.5625.07300

30.2640.425.11280

43.9558.7525.2260

63.2284.6625.32240

88.95119.525.54220

121.2163.825.97200

163.3222.426.54180

208.228827.71160

252.5358.929.65140

286.3427.232.99120

295.6481.738.62100

264.5513.948.5480

180.9525.565.5760

59.42527.188.7340

0.9436527.199.8220

[kJ/kg][kJ/kg][%][K]

Refrigeration effect

Heat of conversion

para-H2concentration

T

LH2, 99.9% Para- H2



Inner vessel

outer vessel


(ex) 300K, 25% Para- H2



w/o VCS

0 1 2 3 4 5 6 72.8

3

3.2

3.4

3.6

3.8

4

Time[hr]

V liq

uid

[gal

]

VliquidVliquid

0 1 2 3 4 5 6 717

18

19

20

21

22

23

24

Time [hr]

T[K]

TT

0 1 2 3 4 5 6 72.8

3

3.2

3.4

3.6

3.8

4

Time[hr]

V liq

uid

[gal

]

VliquidVliquid

0 1 2 3 4 5 6 717

18

19

20

21

22

23

24

Time [hr]

T[K]

TT

w/ VCS + p-o converter



Ortho-Para H2 Converters



Active cooling with miniature JT expansion device

15 20 25 30 35 40 4530

34

38

42

46

50

P [psi]

T[K]

0.45K

0.9K

1.35K

1.8K

Temperature drop through JT valve

LH2, 99.9% Para- H2



Inner vessel

outer vessel


(ex) 300K, 25% Para- H2

(Courtesy : The Lee Company)



Future Plans•• Densified liquid hydrogen systemDensified liquid hydrogen system

–– To produce To produce larger quantitylarger quantity of LH2 at the field facilityof LH2 at the field facility–– To perform To perform inin--line LN2 line LN2 precoolerprecooler and and orthoortho--parapara hydrogen converterhydrogen converter testtest–– To integrate To integrate inline JT expansion deviceinline JT expansion device in the in the densifierdensifier–– To integrate To integrate fuel cell powered backup powerfuel cell powered backup power system.system.

•• Development of vapor cooled shield (VCS) tank with Development of vapor cooled shield (VCS) tank with parapara--toto--orthoortho H2 H2 converter converter

–– To design and fabricate To design and fabricate 10 Gallon VCS LH2 storage tank10 Gallon VCS LH2 storage tank with inline with inline parapara--toto--orthoortho H2 converterH2 converter

–– To integrate To integrate inline JT expansion deviceinline JT expansion device in the VCSin the VCS–– To conduct To conduct catalysts performance testcatalysts performance test for for parapara--toto--orthoortho hydrogen conversion or hydrogen conversion or

interconversioninterconversion between orthobetween ortho--H2 and paraH2 and para--H2 (ex. Iron, nickel, copper H2 (ex. Iron, nickel, copper supported metal transition catalysts to increase supported metal transition catalysts to increase parapara--toto--orthoortho conversion)conversion)

–– To perform To perform pressurization testpressurization test by transferring densified LH2 into VCS tank in by transferring densified LH2 into VCS tank in subsub--atmospheric environment, and conduct atmospheric environment, and conduct boilboil--off reduction testoff reduction test..

long term zbo(zero-boil-off) liquid hydrogen storage tanks · long term zbo lh2 storage tank –...

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