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随着燃气轮机参数的提高和稳定低排放运行工况的拓宽,对燃烧的要求也越来越高。柔和燃烧作为一种有潜力的燃烧技术,具有温度均匀、燃烧稳定和污染物排放低等优点,而如何在燃烧室内组织流动是实现柔和燃烧的关键。采用高速射流引射掺混的方式可以较好的满足柔和燃烧产生所需的条件。预混射流喷嘴结构和布置对流场和燃烧特性有重要影响,如何选择射流喷嘴结构值得进一步研究。本文通过实验和数值模拟相结合的方式,研究了柔和燃烧器中预混射流喷嘴的旋流强度对燃烧器流动结构和燃烧排放的影响。结果表明,旋流能增强燃料/空气的掺混,低旋流作用下能使喷嘴出口掺混不均匀度ISMD下降0. 15左右;但是喷嘴旋流对燃烧室的烟气回流有减弱的作用,使回流区向喷嘴和中轴线靠近;同时,旋流会造成温度场和火焰面不均匀分布,略微拓宽燃烧工况范围并略微增加火焰的稳定性。实验结果表明喷嘴旋流进气角从0°变化到45°时,NOx排放随旋流角的增大而增加。 相似文献
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厦门抽水蓄能电站上水库面板堆石坝上游填筑区采用库内石料场开采的弱微风化料,下游填筑区利用库盆剥离的全风化土料,上、下游填筑区由于料源组成不同存在一定的压缩模量差,设计采取了调整填筑区分界面倾角、设置过渡区等关键技术工程措施,并进行了三维有限元应力应变分析计算,成果表明,可保证大坝的变形协调及安全稳定性。 相似文献
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In order to investigate the influence of MnO2 modification methods on the catalytic performance of CuO/CeO2 catalyst for NO reduction by CO,two series of catalysts(xCuyMn/Ce and xCu/yMn/Ce) were prepared by co-impregnation and stepwise-impregnation methods,and characterized by means of X-ray diffraction(XRD),Raman spectra,H2-temperature programmed reduction(H2-TPR),in situ diffuse reflectance infrared Fourier transform spectra(in situ DRIFTS) techniques.Furthermore,the catalytic performances of these catalysts were evaluated by NO+CO model reaction.The obtained results indicated that:(1) The catalysts acquired by co-impregnation method exhibited stronger interaction owing to the more sufficient contact among each component of the catalysts compared with the catalysts obtained by stepwise-impregnation method,which was beneficial to the improvement of the reduction behavior;(2) The excellent reduction behavior was conducive to the formation of low valence state copper species(Cu+/Cu0) and more oxygen vacancies(especially the surface synergetic oxygen vacancies(SSOV,Cu+-□-Mn(4–x)+)) during the reaction process,which were beneficial to the adsorption of CO species and the dissociation of NO species,respectively,and further promoted the enhancement of the catalytic performance.Finally,in order to further understand the difference between the catalytic performances of these catalysts prepared by co-impregnation and stepwise-impregnation methods,a possible reaction mechanism(schematic diagram) was tentatively proposed. 相似文献
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通过电影<菊豆>在安徽黟县南屏序秩堂和<大红灯笼高高挂>在山西祁县乔家大院的拍摄,阐述了中国传统民居在电影中演绎出的丰富情感,说明民居建筑在电影艺术中不可低估的作用. 相似文献
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上市公司的长期投资价值取决于公司的经营管理水平和财务状况的好坏,而复合财务系数能体现公司的整体财务、经营状况.在确认上市公司复合财务系数评价指标体系的基础上,应用主成分分析法和灰色关联度的计算方法对各财务指标进行综合,得到一种新的复合财务系数计算方法,并把这种方法应用到电力类上市公司的分析上,得到了比较满意的结果,从而为投资者作出投资判断提供了客观、合理的决策依据. 相似文献
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从相容性、兼容性、周时性及个体解释四方面阐述了功能的动态性特征,分析了当代建筑功能的发展趋势,体现了功能动态特征的形式化,指出建筑师应创作出与动态功能体系相适应的新的建筑空间形式。 相似文献