simulation of the efficiency of hydrogen recombiners as safety devices
Download
Skip this Video
Download Presentation
Simulation of the efficiency of hydrogen recombiners as safety devices

Loading in 2 Seconds...

play fullscreen
1 / 28

Simulation of the efficiency of hydrogen recombiners as safety devices - PowerPoint PPT Presentation


  • 142 Views
  • Uploaded on

Simulation of the efficiency of hydrogen recombiners as safety devices. Ernst-Arndt Reinecke, Stephan Kelm, Wilfried Jahn, Christian Jäkel, Hans-Josef Allelein. International Conference on Hydrogen Safety September 12-14, 2011, San Francisco, CA. Overview.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Simulation of the efficiency of hydrogen recombiners as safety devices' - caraf


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
simulation of the efficiency of hydrogen recombiners as safety devices

Simulation of the efficiency of hydrogen recombiners as safety devices

Ernst-Arndt Reinecke, Stephan Kelm, Wilfried Jahn, Christian Jäkel, Hans-Josef Allelein

International Conference on Hydrogen Safety

September 12-14, 2011, San Francisco, CA

overview
Overview

Simulation of the efficiency of hydrogen recombiners as safety devices

  • Passive auto-catalytic recombiner (PAR)
  • Goal of the numerical study
  • Scenario investigated
  • Model approach
  • Results
commercial pars in nuclear power plants
Commercial PARs in Nuclear Power Plants

Vendors

  • AECL, Canada
  • AREVA, France/Germany
  • NIS, Germany

Source: Siempelkamp

operational boundary conditions
Operational boundary conditions

NPP containment

  • large temperature and density gradients
  • large natural convection loops
  • large geometry (20,000-70,000 m³, typical length scales 5-50 m)
  • steam-inertized in early accident phase

Typical H2 and FC applications

  • significant smaller scales
  • different thermal hydraulic conditions

PAR applicability ?

NPP

H2 & FC

GOAL:

experiment
Experiment

Source: CEA

  • GARAGE facility at CEA/France
  • single vehicle private garage (~40 m³)
  • concentration measurement at ~60 pos.

Test 1: He release (~2 g/s) for ~2 min

data recently published:Gupta et al., Int J Hydrogen Energy 34 (2009) 5902–5911

approach
Approach

Scenario based on GARAGE experiment (CEA)

  • Simulation of the helium release and distribution scenario and validation against experimental data
  • Replace helium by hydrogen and verify the calculated distribution
  • Add a PAR to the scenario and compare mitigated/unmitigated scenario
coupled modeling approach
Coupled Modeling Approach

Micro Scale

Meso Scale

Macro Scale

REKO-DIREKT(in-house)

ANSYS CFX

par model reko direkt
Output: T, yi, m

natural convection

Chimney

chemical (catalytical) reaction

mass/heat transfer

Catalystsection

Input: T, yi, p

PAR model: REKO-DIREKT
slide14
REKO-DIREKT

REKO-DIREKT  CFX- Outlet gas temperature- Outlet gas composition- Mass flow through PAR

REKO-DIREKT  CFX

T / °C

yH2 / Vol.-%

CFX  REKO-DIREKT- Inlet gas temperature- Inlet gas composition- Pressure

unmitigated release setup
Unmitigated release - setup
  • Physical Model:
  • Half Symmetry
  • RANS equations
  • Ideal gas equation of state
  • Isothermal
  • SST-model incl. buoyancy prod. & dissipation
  • Injection
    • He: 240 g (1,99 g/s)
    • H2: 120 g (0,99 g/s)
  • Wall functions at inner walls
  • Vent: Outlet Boundary
mitigated release setup
Mitigated release - setup
  • Physical Model:
  • Half Symmetry
  • RANS equations
  • Ideal gas equation of state
  • SST-model incl. buoyancy prod. & dissipation
  • Injection
    • H2: 120 g (0,99 g/s)
  • Wall functions at inner walls
  • Fixed Wall Temperature
  • Temperature dependent properties
  • No heat radiation
  • Vent: Outlet Boundary
performance estimates
Performance (estimates)

Processor

  • 1 CPU Quadcore I7-860, 2.8 GHz
  • Open Suse Linux 11.3
  • CFX 12.1

Calculation time (1200 s)

  • unmitigated scenario: ~10 d
  • mitigated scenario: ~40 d
    • REKO-DIREKT: ~6 min
    • more time steps
    • more gas components (H2+O2+N2+H2O)
conclusions 1 2
Conclusions (1/2)

Goal

  • investigate the applicability of PAR from NPP containment to typical H2&FC application
    • significant differences in operational boundary conditions
  • first study based on GARAGE experiment, performed with ANSYS-CFX and REKO-DIREKT

Results

  • H2 injection of 1.5 m³, flammable cloud was removed within 10 minutes
  • hot exhaust plume promotes the transport of hydrogen rich gas mixture towards the PAR inlet
conclusions 2 2
Conclusions (2/2)

Next steps

  • parameter variation
    • injection rate, location, and direction
    • PAR design and number
    • geometry of the enclosure
  • consideration of possible PAR ignition scenarios
  • validation against mitigation experiments in new multi-compartment facility, currently under construction at JÜLICH
ad