hydrogen energy

1
Hydrogen Subsonic Upward Release and Dispersion
Experiments in Closed Cylindrical Vessel
Denisenko V.P.1, Kirillov I.A.1, Korobtsev S.V.1,
Nikolaev I.I.1, Kuznetsov A.V.2, Feldstein
V.A.3, Ustinov V.V.3 1 RRC
Kurchatov Institute 1, Kurchatov Sq.,
Moscow, 123182, Russia 2
NASTHOL 6,
Shenogin str., Moscow, 123007, Russia
3 TsNIIMash 4, Pionerskaya,
Korolev, 141070, Russia
2

• Context Russian RD Programme Codes an Systems
  for Hydrogen Safety
• grant of Russian Ministry of Science and
  Education
• (2004-2006, cont. July 2007-2009)
• for safety provision of national hydrogen
  infrastructure
• scientific basis for development of regulatory
  documents (codes/standards)
• minimal number and allocation of sensors in
  confined areas
• prototypes for subsequent commercialization of
  tools/components forintegrated safety systems
• sensors
• recombiners
• inhibitors

3
Context Problem Allocation of sensors in
confined areas

• Technical questions
• How many ? What is a minimal number of gas
  detectors, which should be used in confined area,
  for safety provision ?
• Where ?How should they be spatially allocated?
• Land use problem
• absence of free space -gt multiple-use of space -gt
  confined sites

undeground parking, 100, 5 kg H2 per auto
4
Context Problem Allocation of sensors in
confined areas
Practical reference case according to current
technical regulation of Ministry of Transport
(VCN 01-89 Minavtotrans) Ministry of Emergency
(NPB 105-03) gas-fueled autotransport
facilities and premises (parking, workshop, etc.)
of category A should be equipped with
gas-analyzers and alarm systems
- propane-buthane
5
Context Problem - Allocation of sensors in
confined areas
Empirical approach Qualitative
guidelines Sensors should be positioned to
detect any gas accumulation before it creates a
serious hazard. The selection and use of
flammable gas detectors, HSE, TD05/035, 2004
(p.8) Hydrogen detectors are typically placed
above a likely leak point, where hydrogen may
accumulate, and at the intake of ventilation
ducts. ISO-TR-15916 (p.5)
6
Context Problem - Allocation of sensors in
confined areas
Empirical approach Quantitative
guidelines TU-gas-86. Requirements on
arrangement of the indicators and
gas-analysers RD BT 39-0147171-003. Requirements
on arrangement of stationary gas-analysers in
industrial facilities and on outdoor sites of oil
and gas industry 1 sensor per 100 m2
Restricted application for propane-buthane
only
7
Context Problem - Allocation of sensors in
confined areas

• Practical need
• Quantitative engineering guidelines (rational
  procedure) for selection of
• a minimal number of sensors and
• their spatial allocation within given confined
  space, which should be protected
• Research prior art
• indirect relevance only
• Extensive database for jets/plumes under open
  space conditions
• For releases into confined space fire detectors
  allocation studies

8
Scope of reported research work

• Overall goal
• experimental characterization of the hydrogen
  sub-sonic release and distribution inside of
  confined, unventilated space
• baseline (reference) data for subsequent studies
• certain, accurate, repeatable, verifiable
• Technical objectives
• qualitative characterization of basic gas-dynamic
  patterns
• quantitative measurements of ignitable envelope
  evolution

- small foreseeable leakage scenario
9

• Approach Schiphol principle Mind your
  uncertainties !
• minimize experimental uncertainties ALAPR
• identify and document uncertainties
• balance performance - uncertainty
• propose affordable design of experiment

10
Approach Analysis of experimental uncertainties
Source of uncertainty Variable Is controlled by Effect
boundary conditions chamber geometry rigid walls "membrane effects" are absent
  external thermal fluxes temperature difference externally-driven convective effects are absent
  external mass fluxes gas-tight head leakage effects are absent
initial conditions gas pressure pressure gauge in gas FL
  gas temperature temperature sensor in gas FL
  relative humidity of gas RH sensor
performance conditions chemical composition field net of chemical sensors
  temperature field net of tenperature sensors
instrumentation sensor size   ?
  sensor geometry cylindrical ?
  sensor positioning horizontal ?
data acquisition fault-tolerant design  design
test procedure inert gas purging procedure 
11
Experiment Site layout
Schematic drawing of protective concrete dome
(R 6 m, h 6 m, H 12 m)
Ambient conditions (inside of dome) Air
temperature 23ºC Air pressure 758 mm
Hg Relative humidity 64
12
Experiment Experimental chamber
External (left) and internal (right) views of the
experimental chamber
13
Experiment Gauge net layout
2,22 ?
hydrogen source circular tube (internal diameter
- 0,012 m)
14
Experiment Hydrogen sensors
Thermal Conductivity Gauge TCG-3880 (is shown
with open cap) by Xensor Integration
(Netherlands)
Acoustic sensor mounted at electronic card (for
data processing and transmission) by RRC
Kurchatov Institute
15
Experiment Gas supply and control
gas mixture preparation device (GMPD) gas
mixture composition up to 8 components steady
gas flow rate 510-6 , 710-4 m3/s (from 20
to 2560 l/h).
16
Experiment Procedure and Parameters
Series 3 consecutive runs (inert gas purging
between) with the same parameters Ambient
conditions standard Hydrogen
injection direction upward duration 10
min flowrate 0,46 l/sec Data
acquisition Duration during injection and 15
min after its end Temperature sensors 24
(inside), 4 (outside) Hydrogen sensors 24
(inside) Pressure gauge 1 (inside), 1 (outside)
17
Experiment First results Hydrogen concentration
time histories
Time histories for the hydrogen concentrations (
vol.) for the 24 gauges (time duration 0 - 25
min)
18
Experiment First results Basic flow patterns
Pre-test simulations
Evolution of Ignitable Hydrogen-Air Gas Mixture
Cloud
Three-phase evolution of ignitable gas mixture
cloud Step 1 upward propagation of emerging
jet/plume, Step 2 impinging of jet/plume with
ceiling and outward expansion of cloud, Step 3
downward expansion of cloud from ceiling to
floor.
19
Experiment First results Basic flow patterns
Experimental results
Evolution of Ignitable Hydrogen-Air Gas Mixture
Cloud
10,05 min
1 min
15 min
5 min
25 min
10 min
hydrogen concentration in vol.
20
Experiment First results Experimental data for
ignitable mixture front speed
Averaged speed of envelope (2 vol.) front
propagation
UNVENT1 series (3 runs) envelope propagation
speed Vert. (upward) - 0,33 m/sec,
Horiz.(outward) - 0,055 m/sec.
Definition of averaged speed using sensor 4 and
sensor 21
21
Experiment First results Reproducibility of
results
Time histories for three different test runs
(sensor 10)
22
Experiment Synchronous behavior of sensors at
symmetric points
Symmetrical character of hydrogen flow in
experimental vessel
23
Conclusions

• The experimental set-up for pre-normative studies
  of hydrogen release and dispersion inside of a
  medium-scale (4 m3), closed horizontal
  cylindrical vessel was prepared and adjusted.
• The first precise measurements (3 test runs) of
  the time evolution of explosive hydrogen cloud
  after hydrogen injection under the
  well-controlled boundary/initial conditions have
  been carried out using spatially distributed 24
  hydrogen sensors and 24 thermocouples.
• Analysis of the simultaneous experimental records
  for the different spatial points permits to
  delineate the basic flow patterns of hydrogen
  subsonic release in closed vessel in contrast to
  hydrogen jet release in open environment.
• The quantitative data were obtained for the
  averaged speeds of ignitable cloud envelop (50
  fraction of the Lower Flammability Limit (LFL)
  2 vol.) propagation in the vertical and
  horizontal directions.
• It was proposed to use the uncertainty analysis
  of the experiments and simulations for benefit
  of the hydrogen safety studies

24

• ACKNOWLEDGMENTS
• This work was supported by
• Russian Ministry of Science and Education
  and
• EU HYPER project (partially).

25
Thanks for your attention ! Questions/comments
kirillov.igor_at_gmail.com
26
Context Problem Uncertainties in hydrogen
safety studies
SBEP-V1
Experiment vs Simulation
(VNIIPO, 1988)
(HySafe, 2005)
Figure 1. (a) Shape of the
experimental vessel
Figure 8. Comparison between models (250 min
after the end of release).
From www.hysafe.org/download/362/D23-01.doc
27
Context Problem Uncertainties in hydrogen
safety studies
SBEP-V1
Experimental uncertainty during measurement
phase (250 min), it was impossible to control
the thermal boundary conditions