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过程工程学报 2005
Two-dimensionalSimulationforHydrogen/AirCombustioninaMonolithReactorKeywords: micro-reactor,monolith,combustion,catalysis,hydrogen,simulation Abstract: Recentstudiesonhydrogencombustionwerereviewedbriefly.Thelaminarflowandcombustionofpremixedhydrogen/airmixtureinacylindricalchannelofamonolithreactorwithandwithoutcatalyticwallwasnumericallymodeledbysolvingtwo-dimensional(2-D)NavierStokes(NS)equations,energyequation,andspeciesequations.Eightgasspeciesandtwentyreversiblegasreactionswereconsidered.ThecontrolvolumetechniqueandtheSIMPLEalgorithmwereusedtosolvethepartialdifferentialequations.Thestreamlinesoftheflowfield,temperaturecontours,theentrancelength,andtheconcentrationfieldswerecomputed.Itisfoundthattheentrancezoneplaysanimportantroleonflowandtemperatureaswellasspeciesdistribution.Therefore,theflowcannotbeassumedeitherasfullydevelopedorasplugflow.Thereisasmallbutstrongthermalexpansionzonebetweenthewallandtheentrance.Bothdiffusionandconvectionaffecttheheatandmasstransferprocessesintheexpansionzone.Thustheequationsofmomentum,energyandspeciesconservationsshouldbeusedtodescribehydrogen/aircombustioninthemonolithreactor.Thehot-spotlocationandconcentrationfieldofthehomogeneouscombustionisstronglyinfluencedbytheinletvelocityandtemperature,andtheequivalenceratio.Thecatalyticcombustionofpremixedhydrogen/airmixtureoverplatinumcatalyst-coatedwallinacylindricalchannelwasalsosimulated.
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