Kurchatov Institute

Hydrogen Subsonic Upward Release and Dispersion Experiments in Closed Cylindrical Vessel

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

Kurchatov Institute

Context: Russian R&D 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

recombinersinhibitors…

Kurchatov Institute

Context: Problem: Allocation of sensors in confined areas

Technical questions:

1. How many ? What is a minimal number of gas detectors, which should be used in confined area, for safety provision ?

2. Where ?How should they be spatially allocated?

Land use problem: absence of free space -> multiple-use of space -> confined sites

undeground parking, 100+, ~5 kg H2 per auto

Kurchatov Institute

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

Kurchatov Institute

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)

Kurchatov Institute

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

Context: Problem - Allocation of sensors in confined areas

Kurchatov Institute

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

Context: Problem - Allocation of sensors in confined areas

Kurchatov Institute

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

Kurchatov Institute

Approach: “Schiphol principle”: Mind your uncertainties !

• minimize experimental uncertainties ALAPR

identify and document uncertaintiesbalance ‘performance - uncertainty“ propose affordable design of experiment

Kurchatov Institute

Source of uncertainty Variable Is controlled by Effect

boundary conditions chamber geometry rigid walls "membrane effects" are absent

  external thermal fluxes temperature differenceexternally-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  +

Approach: Analysis of experimental uncertainties

Kurchatov Institute

Schematic drawing of protective concrete dome (R = 6 m, h = 6 m, H = 12 m)

Ambient conditions (inside of dome):Air temperature 23ºCAir pressure 758 mm HgRelative humidity 64 %

Experiment: Site layout

Kurchatov Institute

External (left) and internal (right) views of the experimental chamber

Experiment: Experimental chamber

Kurchatov Institute

Experiment: Gauge net layout

2,22 м

hydrogen source: circular tube (internal diameter - 0,012 m)

Kurchatov Institute

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”

Experiment: Hydrogen sensors

Kurchatov Institute

gas mixture preparation device (GMPD):

gas mixture composition up to 8 components

steady gas flow rate [5*10-6 , 7*10-4 ] m3/s (from 20 to 2560 l/h).

Experiment: Gas supply and control

Kurchatov Institute

Experiment: Procedure and Parameters

Series3 consecutive runs (inert gas purging between) with the same parameters

Ambient conditions standard

Hydrogen injectiondirection upwardduration 10 minflowrate 0,46 l/sec

Data acquisitionDuration during injection and 15 min after its endTemperature sensors 24 (inside), 4 (outside)Hydrogen sensors 24 (inside)Pressure gauge 1 (inside), 1 (outside)

Kurchatov Institute

Time histories for the hydrogen concentrations (% vol.) for the 24 gauges (time duration 0 - 25 min)

Experiment: First results: Hydrogen concentration time histories

Kurchatov Institute

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.

Experiment: First results: Basic flow patterns: Pre-test simulations

Evolution of Ignitable Hydrogen-Air Gas Mixture Cloud

Kurchatov Institute

Evolution of Ignitable Hydrogen-Air Gas Mixture Cloud

1 min

5 min

10 min

10,05 min

15 min

25 min

hydrogen concentration in % vol.

Experiment: First results: Basic flow patterns: Experimental results

Kurchatov Institute

Definition of averaged speed using sensor 4 and sensor 21

Averaged speed of envelope (2 % vol.) front propagation

UNVENT#1 series (3 runs)

envelope propagation speed

Vert. (upward) - 0,33 m/sec, Horiz.(outward) - 0,055 m/sec.

Experiment: First results: Experimental data for ignitable mixture front speed

Kurchatov Institute

Time histories for three different test runs (sensor 10)

Experiment: First results: Reproducibility of results

Kurchatov Institute

Experiment: Synchronous behavior of sensors at symmetric points

Symmetrical character of hydrogen flow in experimental vessel

Kurchatov Institute

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

Conclusions:

Kurchatov Institute

ACKNOWLEDGMENTS

This work was supported by

• Russian Ministry of Science and Education and

• EU HYPER project (partially).

Kurchatov Institute

Thanks for your attention !

Questions/comments:

kirillov.igor@gmail.com

Thanks for your attention !

Questions/comments:

kirillov.igor@gmail.com

Kurchatov Institute

SBEP-V1

From: www.hysafe.org/download/362/D23-01.doc

D=5.5 m

D=2.2 m

Figure 1. (a) Shape of the experimental vessel

0.001

0.010

0.100

1.000

10.000

0.0 1.0 2.0 3.0 4.0 5.0 6.0

Distance from top (m)

Cp

/ Co

BRE BRE-A NCSaNCSb FZJ FZKGXC UUa UUbCEA WUT DNVUPM INR Cp / Co = 1Cp / Co = 2 Cp / Co = 1/2

Figure 8. Comparison between models (250 min after the end of release).

Experiment vs Simulation(VNIIPO, 1988) (HySafe, 2005)

Context: Problem – Uncertainties in hydrogen safety studies

Kurchatov Institute

D=5.5 m

D=2.2 m

Experimental uncertainty: during measurement phase (250 min), it was impossible to control the thermal boundary conditions

Context: Problem – Uncertainties in hydrogen safety studies

SBEP-V1