共查询到15条相似文献,搜索用时 78 毫秒
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本文通过自行研制的多孔介质燃烧实验系统,研究了液体燃料在热多孔介质中的燃烧可行性及其燃烧特性.燃烧系统包括燃烧室、供气系统、供油系统和测量系统等,该系统分别以气体和液体作为燃料,先通过多孔介质内的预混合燃烧对多孔介质固相进行预热,然后喷入液体燃料,实现燃烧,实验证实了液体燃料在热多孔介质内汽化及自维持燃烧的可行性,并讨论了空气量和喷油量等对燃烧室温度的影响. 相似文献
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多孔介质预混燃烧中辐射属性影响的敏感性分析 总被引:1,自引:0,他引:1
建立了惰性多孔介质中预混合燃烧的数学模型,采用辐射传递的有限体积法求解固相能量方程中的辐射源项,研究多孔介质热辐射在燃烧系统中的作用,考察辐射属性(吸收系数和散射反照率)对轴向温度场和辐射热流量影响的敏感性。研究表明,辐射属性参数波动对预测结果影响明显,固体热辐射在多孔介质预混燃烧中的影响不可忽略。 相似文献
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本文运用电容层析成像(ECT)方法,以非侵入的方式,对多孔介质燃烧中的火焰分布进行可视化测量.针对高孔隙率泡沫陶瓷(8PPI)的孔隙结构特点,提出了一种"十字架形"几何结构模型,用丁泡沫型多孔介质内甲烷-空气预混燃烧的二维数值模拟.ECT成像结果与数值模拟结果吻合,显示了两个不同学科信息的融合性和互验性. 相似文献
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考虑弥散效应的多孔介质中超绝热燃烧的数值模拟 总被引:2,自引:0,他引:2
研究多孔介质内往复流动下的超绝热燃烧。一维模型包括气体输运、多孔介质固体的辐射、导热和气固两相间的对流换热。通过数值计算研究超绝热燃烧的形成、以及弥散效应、当量比和多孔介质材料本身对超绝热燃烧特性的影响。计算结果的有效性通过实验进行了验证并取得了相同的趋势。结果表明,组分弥散效应对气体温度分布和反应热影响很小;同一工况下,不考虑气体混合物的热弥散效应,会导致过高的气体温度计算值。同时,计算结果表明小孔径的多孔介质更有利于贫可燃极限的扩展,对30 ppi的多孔介质燃烧器,得到了当量比为0.092的可燃极限。 相似文献
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将Rosseland辐射模型和双通量法结合,对瓦斯气体在泡沫陶瓷中预混燃烧辐射换热计算方法进行研究.数值模拟的结果与试验结果吻合比较好,证明提出的辐射换热计算方法是有效的. 相似文献
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M.M. Keshtkar S.A. Gandjalikhan Nassab 《Journal of Quantitative Spectroscopy & Radiative Transfer》2009,110(17):1894-1907
This paper describes a theoretical study to investigate the heat transfer characteristics of porous radiant burners (PRBs). In the present work, a 2-D rectangular model is used to solve the governing equations for porous medium and gas flow before the premixed flame to the exhaust gas. The gas and the solid phases are considered in non-local thermal equilibrium and combustion in the porous medium is modeled by considering a non-uniform heat generation zone. The homogeneous porous media, in addition to its convective heat exchange with the gas, may absorb, emit and scatter thermal radiation. The radiation effect in the gas flow is neglected but the conductive heat transfer is taken into account. In order to analyze the thermal characteristics of porous burners, the coupled energy equations for the gas and porous medium in steady condition are solved numerically and the discrete ordinates method (DOM) is used to obtain the distribution of radiative heat flux in the porous media. Finally, the effects of various parameters on the performance of porous radiant burners are examined. The present results are compared with some reported theoretical and experimental results by other investigators and good agreement is found. 相似文献
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P. M. Krishenik K. G. Shkadinskii 《Russian Journal of Physical Chemistry B, Focus on Physics》2009,3(1):56-62
An analysis of the characteristics of the combustion front in a multilayer porous system with radiative heat transfer and filtration mass transfer of gaseous reactants into the exothermic conversion zone is presented. At moderate pressures, the mass of the gas in the porous layer is smaller than that required by stoichiometry, and, therefore, filtration transport without diffusion from the ambient medium occurs. It was taken into account that the bulk heat release in the porous media can be limited by both the kinetics of the exothermic chemical reaction and the filtration transport of a gaseous reactant from the ambient medium. The effect of filtration on the characteristics of relay-race combustion was examined. The characteristics of the front and the dynamics of the conversion of the elements of the discrete system were determined. The characteristics of the relay-race filtration combustion front under conditions of heat losses into the ambient medium were examined, and the possibility of existence of two steady regimes, with a low- and a high-temperature relay-race combustion front, was demonstrated. At heat losses above a critical level, relay-race combustion extinguishes. A numerical analysis of relay-race combustion regimes under nonadiabatic conditions showed that the low-temperature front is absolutely unstable and made it possible to study the dynamics of the onset of high-temperature relay-race filtration combustion. 相似文献
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《Revue Generale de Thermique》1998,37(9):743-758
Heat transfer is strongly involved in many scientific and technologic domains and the French heat transfer laboratories and networks cooperating is this field are first located. The analysis of the main industrial activities demanding heat transfer competence helps one first to identify some up-to-date technological challenges. It appears clearly that connecions are to be reinforced between disciplines like heat transfer, fluid mechanics, combustion, material science, optics, biology… Scientific objectives are then scanned through, by splitting the research activities between mature topics (radiation, particularly in semi-transparent media; convection and thermoconvective instabilities; heat transfer in porous media…), emerging (heat transfer with change of phase, convective heat transfer enhancement by active control in the boundary layer, inverse techniques…) and incipient ones. Among some promising new topics, let us mention microscale heat transfer, and also bioheat transfer. 相似文献