Heat and Mass Transfer

, Volume 48, Issue 4, pp 591–598

2D numerical simulation of passive autocatalytic recombiner for hydrogen mitigation

Original

DOI: 10.1007/s00231-011-0906-5

Cite this article as:
Gera, B., Sharma, P.K. & Singh, R.K. Heat Mass Transfer (2012) 48: 591. doi:10.1007/s00231-011-0906-5
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Abstract

Resolving hydrogen related safety issues, pertaining to nuclear reactor safety has been an important area of research world over for the past decade. The studies on hydrogen transport behavior and development of hydrogen mitigation systems are still being pursued actively in various research labs, including Bhabha Atomic Research Centre (BARC), in India. The passive autocatalytic recombiner (PAR) is one of such hydrogen mitigating device consisting of catalyst surfaces arranged in an open-ended enclosure. In the plate type recombiner design sheets made of stainless steel and coated with platinum catalyst material are arranged in parallel inside a flow channel. The catalyst elements are exposed to a constant flow of a mixture of air, hydrogen and steam, a catalytic reaction occurs spontaneously at the catalyst surfaces and the heat of reaction produces natural convection flow through the enclosure. Numerical simulation and experiments are required for an in-depth knowledge of such plate type PAR. Specific finite volume based in-house 2D computational fluid dynamics (CFD) code has been developed to model and analyse the working of these recombiners and has been used to simulate one literature quoted experiment. The validation results were in good agreement against literature quoted German REKO experiments. Parametric study has been performed for particular recombiner geometry for various inlet conditions. Salient features of the simplified CFD model developed at BARC and results of the present model calculations are presented in this paper.

List of symbols

ρ

Density of mixture, (kg/m3)

p

Absolute pressure of the mixture, (Pa)

T

Absolute temperature of the mixture, (K)

Ru

Universal gas constant, (8,314 J/Kmol K)

Yi

Mass fraction of ith species

MWi

Molecular weight of ith species

[H2]

Molar concentration of hydrogen, (Kmol/m3)

XH2in

Mole fraction of hydrogen at recombiner inlet

Tin

Temperature of hydrogen air mixture at recombiner inlet (K)

Vin

Velocity of hydrogen air mixture at recombiner inlet (m/s)

u

X-component of velocity (m/s)

v

Y-component of velocity (m/s)

μ

Dynamic viscosity, (Ns/m2)

g

Acceleration due to gravity, (9.81 m/s2)

Cp

Specific heat, (J/kg-K)

k

Thermal conductivity (W/m K)

D

Diffusion coefficient (m2/s)

ST

Source term in energy equation

\( S_{{Y_{i} }} \)

Source term in species transport equation of ith species

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  1. 1.Reactor Safety DivisionBhabha Atomic Research CentreTrombay, MumbaiIndia

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