Heat loss reduction and hydrocarbon combustion in ultra-micro combustors for ultra-micro gas turbines
Heat loss reduction and hydrocarbon combustion in ultra-micro combustors for ultra-micro gas turbines
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DOI：
10.1016/j.proci.2008.06.002
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发表时间：
2009
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影响因子：
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通讯作者：
T. Sakurai;S. Yuasa;Taku Honda;Shoko Shimotori
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文献类型：
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作者：
T. Sakurai;S. Yuasa;Taku Honda;Shoko Shimotori
降低热损失和碳氢燃料的使用是超微型燃气轮机(UMGT)燃烧室发展的关键。提出了一种减小超微燃烧室热损失影响的方法。热损失比定义为燃烧室的热损失速率与燃烧室内的热释放速率之比，与空间加热率有关，在一些氢/空气预混的平焰超微燃烧室上进行的实验表明，热损失比与空间加热率的关系为∼−0.92/ℓ(ℓ(燃烧室的特征长度)。从降低热损失的角度来看，在紧凑型超微燃烧室中实现高SHR燃烧是实现UMGT燃烧室实用化的关键。对于碳氢化合物的燃烧，丙烷燃料采用有催化剂和无催化剂的平焰燃烧方法。该平焰燃烧器内径为18.5 mm，高度为3.5 mm，体积为0.806 cm~3，可在无催化剂的情况下在燃烧室内成功形成丙烷火焰，并获得3370 mW/(MPam3)的极高SHR。当m·a=0.06g/S时，火焰稳定区较宽，当量比在0.5和0.7之间时，燃烧效率可达99.4%以上，采用浸铂多孔板的平焰燃烧器表现出催化燃烧，但没有改善燃烧特性。另一方面，采用表面覆盖铂的喷嘴的平焰燃烧器表现出催化和气相燃烧的结合，由于燃烧室内气相燃烧后燃烧气体中的CO被氧化，在更大的当量比范围内提高了燃烧效率。
For the development of ultra-micro combustors for Ultra-Micro Gas Turbines (UMGT), heat loss reduction and hydrocarbon fuel use are the key issues. An approach for reducing the effect of heat loss in ultra-micro combustors was proposed. The heat loss ratio (HLR), which was defined as the ratio of heat loss rate from a combustor to heat release rate in the combustor, was related to the space heating rate (SHR), and experiments using some flat-flame ultra-micro combustors with hydrogen/air premixture exhibited the relation of HLR∼SHR−0.92/ℓ (ℓ, characteristic length of combustor). From the viewpoint of heat loss reduction, burning at high SHR in compact ultra-micro combustors is essential for a practical UMGT combustor. As for hydrocarbon combustion, the flat-flame burning method with and without catalyst was applied to propane fuel. The flat-flame combustor, having an inner diameter of 18.5mm, a height of 3.5mm, and a volume of 0.806cm3, could form a propane flame successfully in the chamber without a catalyst and achieved an extremely high SHR of 3370MW/(MPam3). Flame stable region was wide enough, and the combustion efficiency achieved was more than 99.4% between the equivalence ratios of 0.5 and 0.7 at m˙a=0.06g/s. The flat-flame combustor using a Pt-impregnated porous plate showed catalytic combustion, but did not improve the combustion characteristic. On the other hand, the flat-flame combustor using a nozzle whose surface was covered with Pt showed a combination of catalytic and gas-phase combustion with improved combustion efficiency for a wider range of equivalence ratios, due to CO oxidation in the burned gas after gas-phase combustion in the chamber.