Transcript HYDROGEN TANK FILLING EXPERIMENTS AT THE JRC-IE GASTEF FACILITY

San Francisco on 13 September 2011 – 4th ICHS
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International Conference on Hydrogen Safety - 4
September 12-14, 2011
San Francisco, California, USA
Hydrogen Tank Filling Experiments
at the JRC-IET GasTeF Facility
IET - Institute for Energy and Transport
Joint Research Centre, European Commission
Petten - The Netherlands
http://ie.jrc.ec.europa.eu/
http://www.jrc.ec.europa.eu/
B. Acosta, P. Moretto, N. Frischauf,
F. Harskamp and C. Bonato
OUTLINE
San Francisco on 13 September 2011 – 4th ICHS
 Hydrogen storage at high pressures
 Fast filling issues
 GasTeF: Compressed hydrogen Gas Testing Facility
 JRC-IET GasTeF temperature evolution experiment
 Experimental results
 Next steps
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hydrogen storage at high pressures
San Francisco on 13 September 2011 – 4th ICHS
A type 1 tank, or a standard
compressed gas cylinder, is simply a
stainless steel casing holding
compressed gas. It has no extra
covering or accessories, except for the
coating of paint on the outside that
identifies the contained gas.
A type 3 tank is a fully wrapped
composite tank with a metal liner
made out of aluminium or stainless
steel. The composite is wrapped
around the liner. The
mechanical loads of the cylinder
are supported by both liner and wrapping.
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A type 2 tank is slightly
more durable than a
type 1. It has a base
cylinder shell made of aluminium or stainless
steel, and a partial wrapping around the outside
of the cylinder. This wrapping is usually made of a
polyester resin containing glass, aramid or carbon.
A type 4 tank is a fully
wrapped composite
tank with a nonmetallic liner. The
mechanical loads are therefore only supported by
the composite wrapping; the liner itself does not
support the loads  “non-sharing-load” liner
Type 3 and 4 tanks may also have an additional glass fibre wrapping
to protect the tank against external effects
fast filling : safety and convenience aspects
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Tank (re)-fuelling Requirements:
 Avoid exceeding high temperatures in tank  Operating range -40 °C to 85 °C
 Reasonable short filling duration  Max. 3-5 minutes
… however…
 The shorter the filling duration  The higher the temperatures inside the tank
 Higher gas temperatures  Higher filling end pressures to assure a “complete tank filling”
 Three major risks to damage tank materials:
 Over-pressurisation
 Temperatures higher than the maximum allowed 85 °C (for example SAE J2579)
 Over-filling if fuelling occurs at low ambient temperature
The JRC-IET facility GasTeF is an EU reference laboratory designed to carry out
performance verification tests of full-scale high pressure vehicle tanks for hydrogen or
natural gas or of any other high-pressure components
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GasTeF: safe testing of tanks and components
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GasTeF:
Compressed Hydrogen Gas Testing Facility
 Half-buried bunker with an attached gas storage area.
 Designed to endure a sudden energy release equivalent to
50 kg TNT with a safety factor of 10.
 Double walls of heavy-concrete, covered by a 3 meter thick
sand layer armoured by geotextile every thirty centimetres
 The bunker is closed by a gas-tight inner door and after
that by a hydraulically operated 40 tons massive concrete
door sliding on Teflon plates
 The gas detectors form the heart of the safety monitoring
system of the bunker
 Operated under remote control – inertised during testing
GasTeF layout
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1st Containment
pressure vessel
GC and O2 free
H2 detectors
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The cylinders are placed into a sleeve
which contains an inert gas (He, N2...)
and serves as chamber to detect
permeation. The H2 level is measured
using gas chromatography.
H2 / He / CH4
300 bar package
55 kW two-stage piston
compressor up to 880 bar
2nd Containment
Aluminium Sleeve
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GasTeF : fast-filling, cycling and permeation tests on any type of
hydrogen (and methane) tanks
 Static permeation measurement as a function of time on tanks filled up to 70 MPa and up to
temperatures to 100 °C.
Tank Pressure
Bottom Temperature
Top Temperature
400
28
350
26
24
300
22
20
18
16
200
14
150
12
10
100
8
6
50
4
2
0
0
-1
0
1
2
3
4
5
6
Test Duration [h]
7
8
9
10
o
Pressure [bar]
250
Temperature [ C]
 Fast-filling cycling, in which storage tanks
are fast filled and slowly emptied using
hydrogen pressurized up to 70 MPa, for at
least 1000 times to simulate their lifetime in a
road vehicle. During the cycling process the
tank is monitored for leaks and permeation
rates using gas chromatography.
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Local measurement of H2 temperature
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a boom with thermocouples is inserted into the tank
 Temperature measurement at 3
axial (displaceable) and 5 radial
positions
 Measurement with He and with H2
Tank: Raufoss Type 4, 700 bar (29.8 l)
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T Top
5
1
T Boss
T Line
2
6
4
7
8
H2 inflow
3
T Bottom
 The temperature evolution experiment is also used to validate software models for
tanks (see next presentation)
 Experimental data presented hereafter are preliminary results of the on-going
testing campaign to map local temperature evolution inside the tank as a function
of filling rate under different starting conditions (Ti, pi) and final pressure pf
San Francisco on 13 September 2011 – 4th ICHS
He versus H2
120
100
o
Temperature Increase [ C]
Position T5:
Axial: 500 – 525
mm from gas inlet
Radial: 15 to 35 mm
from liner
10
80
60
40
TC-5 He
TC-5 H2
20
0
-1
0
1
2
3
4
5
6
7
Fill rate [bar/s]
 The graph summarises experiments with different filling rates for different pi, pf
and Ti
 In general H2 features a smaller temperature increase than He (evident only at
high fill rates)
Measured temperatures at the inside and
outside of the tank differ significantly
120
110
100
90
80
70
60
50
40
30
20
10
0
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TC-5
T Top
Top_inside
?
Max allowed T
o
Final Temperature, C
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H2
Top_outside
0
1
2
3
4
5
6
Fill rate, bar/s
 The graph summarises experiments with different filling rates and slightly different
pi, pf and Ti
 Temperature rise influenced by filling rate
 Variation in temperature rise at a given filling rate is caused by pf, as well as (Ti, pi)
Long term static pressure tests
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100
P tank
Temperature
90
Pressure [MPa]
o
Temperature [ C]
80
70
60
50
40
30
20
10
30 hours
0
10/12/2010 12:00
11/12/2010 00:00
11/12/2010 12:00
12/12/2010 00:00
Date
 After filling finishes, the temperature sharply decreases due to heat transfer from
inside the tank to its outer surface
 As temperature decreases, pressure does as well and hence it takes several
hours to reach equilibrium values
Filling
Example of fill & emptying cycle
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Pressure
holding
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Emptying
80
70
50
40
30
20
10
0
0
5
10
15
20
25
30
o
Pressure [MPa]
60
Temperature [ C]
90
80
70
60
50
40
30
20
10
0
-10
-20
-30
-40
35
Time [minutes]
 non-linear filling induces a complex (non monotonic) gas temperature evolution
 as soon as filling is finished, gas temperatures inside the tanks follow a stratification
pattern
Next step: temperature control in GasTeF
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 a system to cool down the hydrogen when it is supplied to the tank
 environmental control system to allow simulation of -40°C ambient temperature
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Example of tank temperature dependence on inlet temperature
Temperatures during filling [C]
140
120
Without pre-cooling
100
80
With pre-cooling
TC5, gas
temperature top of
the tank
60
40
20
TC8, Gas inlet
temperature
0
-20
-40
-60
0
20
40
60
80
100 120 140 160 180 200
Time [s]
even without cooling, inlet temperature can increase
control of gas inlet temperature is not easy!
Conclusions
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 measurements are in good agreement with those found in literature
 results show that the maximum gas temperature during filling of a type 4 tank
can locally exceed the limit established in current regulations and standards.
Is this maximum allowed temperature too limiting?
Is this “historical” limit justified for the materials used?
Is it important to consider the duration of the temperature overshoot?
 First results suggest that the low thermal conductivity of the plastic liner
limits the effect of local temperature peaks on the liner itself as well as on the
material of the external shell
Next experimental step is to place the thermocouples touching or
as close as possible to the tank internal surface to obtain accurate
measurements of the liner temperature during filling and emptying
 The results serve to validate the computed fluid dynamic modelling of the fast
filling process, also performed at JRC-IET – See next presentation!
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Thank you for your attention
[email protected]
[email protected]
control by PLCs and specific software tools
San Francisco on 13 September 2011 – 4th ICHS
In normal operation
the facility runs fully
automatically and the
tests are operator
controlled from a
control room situated
in an adjacent
building
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