摘要:
本文选取低硫原油、高硫原油和重石脑油,进行了不同燃烧面积的室外开放空间自由燃 烧实验,获得燃烧速率、火焰温度和测点热辐射通量的实验数据,并使用FDS建立全尺寸模型对 火焰温度和测点热辐射通量进行模拟。 研究结果表明:(1)低硫原油和高硫原油均出现三个燃 烧阶段,在燃烧初期发展阶段燃烧速率近乎以线性趋势增大;稳定燃烧阶段不明显,未出现明显 的多个稳定燃烧阶段;重石脑油出现沸腾燃烧阶段。 (2)油盘中心温度随高度的增加先增大后 减小,火羽流外侧温度随高度增加而减小,这种下降趋势先急后缓;在连续火焰区高温集中,在间 歇火焰区和浮力羽流区温度变化较大。 (3)将燃烧速率曲线自定义到FDS中,可以实现对测点 接收热辐射通量的准确模拟;将圆柱模型中火焰辐射通量分为底部发光区域和上方烟羽流进行 计算时,火源功率越大,计算值与测量值越接近;对于大功率油池火,可以确定“安全距离-时间” 临界曲线,得到距火源中心不同位置处人员可以暴露的时间。
Abstract:
Inthispaper,low-sulfurcrudeoil,high-sulfurcrudeoilandheavynaphthaoilwereselected tocarryoutfreecombustionexperimentwithdifferentcombustionareasinoutdooropenspace,andthe experimentaldataofcombustionrate,flametemperatureandheatradiationfluxatmeasuringpoints wereobtained.Inaddition,FDSwasusedtoestablishafull-sizemodeltoobtainthesimulationresults offlametemperatureandheatradiationfluxatmeasuringpoints.Theresultsshowthat:(1)Bothlowsulfurcrudeoilandhigh-sulfurcrudeoilhavethreecombustionstages.Thecombustionrateincreases almostinalineartrendintheinitialdevelopmentstageofcombustion.Thestablecombustionstageis notobvious,andtherearenotmanyobviousstablecombustionstages.Heavynaphthashowsboiling combustionphase.(2)Thetemperatureatthecenteroftheoilpanfirstincreasesandthendecreases withtheincreaseoftheheight,whilethetemperatureoutsidetheplumedecreaseswiththeincreaseof theheight,andthisdownwardtrendisfirstsharpandthenslow.Inthecontinuousflamearea,thehigh temperatureconcentrationtendstobestable,andintheintermittentflameareaandbuoyancyplume area,thetemperaturedispersiondegreeislarger.(3)Bycustomizingthecombustionratecurveinto FDS,accurate simulation of heat radiation flux received at the measuring point can be achieved.Whentheflameradiationfluxinthecylindricalmodelisdividedintotheluminousregion atthebottomandtheplumeatthetop,thehigherthepowerofthefiresource,thecloserthecalculatedvalueistothemeasuredvalue.Forthehigh-poweroilpoolfire,thecriticalcurveof“safety distance-time” canbedeterminedtoobtainthetimethatpeoplecanbeexposedatdifferentlocationsfromthefiresource.
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