<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Operation of a passive autocatalytic hydrogen recombiner (PAR) has been investigated by means of computational fluid dynamics methods (CFD). The recombiner is a self-active and self-adaptive device used to remove hydrogen from safety containments of light water nuclear reactors (LWR) by means of a highly exothermic reaction with oxygen at the surface of a platinum or palladium catalyst. Different turbulence models (k-ω, k-ɛ, intermittency, RSM) were applied in numerical simulations of: gas flow, heat and mass transport and chemical surface reactions occurring in PAR. Turbulence was found to improve mixing and mass transfer and increase hydrogen recombination rate for high gas flow rates. At low gas flow rates, simulation results converged to those obtained for the limiting case of laminar flow. The large eddy simulation technique (LES) was used to select the best RANS (Reynolds average stress) model. Comparison of simulation results obtained for two- and three-dimensional computational grids showed that heat and mass transfer occurring in PAR were virtually two-dimensional processes. The effect of hydrogen thermal diffusion was also discussed in the context of possible hydrogen ignition inside the recombiner.</p></abstract>

Operation of a passive autocatalytic hydrogen recombiner (PAR) has been investigated by means of computational fluid dynamics methods (CFD). The recombiner is a self-active and self-adaptive device used to remove hydrogen from safety containments of light water nuclear reactors (LWR) by means of a highly exothermic reaction with oxygen at the surface of a platinum or palladium catalyst. Different turbulence models (k-ω, k-ɛ, intermittency, RSM) were applied in numerical simulations of: gas flow, heat and mass transport and chemical surface reactions occurring in PAR. Turbulence was found to improve mixing and mass transfer and increase hydrogen recombination rate for high gas flow rates. At low gas flow rates, simulation results converged to those obtained for the limiting case of laminar flow. The large eddy simulation technique (LES) was used to select the best RANS (Reynolds average stress) model. Comparison of simulation results obtained for two- and three-dimensional computational grids showed that heat and mass transfer occurring in PAR were virtually two-dimensional processes. The effect of hydrogen thermal diffusion was also discussed in the context of possible hydrogen ignition inside the recombiner.

Modelling of a passive autocatalytic hydrogen recombiner – a parametric study

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Nukleonika

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Operation of a passive autocatalytic hydrogen recombiner (PAR) has been investigated by means of computational fluid dynamics methods (CFD). The recombiner is...

Modelling of a passive autocatalytic hydrogen recombiner – a parametric study

Published Online: Mar 12, 2015

Page range: 161 - 169

Received: Aug 14, 2014

Accepted: Nov 27, 2014

DOI: https://doi.org/10.1515/nuka-2015-0002

Keywords
CFD, hydrogen, large eddy simulation, catalytic recombiner, turbulence

© Antoni Rożeń

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Modelling of a passive autocatalytic hydrogen recombiner – a parametric study

Published Online: Mar 12, 2015

Page range: 161 - 169

Received: Aug 14, 2014

Accepted: Nov 27, 2014

DOI: https://doi.org/10.1515/nuka-2015-0002

KeywordsCFD, hydrogen, large eddy simulation, catalytic recombiner, turbulence

© Antoni Rożeń

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
CFD, hydrogen, large eddy simulation, catalytic recombiner, turbulence