共查询到20条相似文献,搜索用时 46 毫秒
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针对凝汽器喉部有低压加热器和汽动给水泵的小汽轮机排汽的布置形式,应用FLUENT计算软件,对某300MW汽轮机凝汽器的喉部流场进行三维数值模拟,分析凝汽器喉部出口流场的分布和能量损失系数的变化。结果表明:小机排汽的存在增大了喉部流场的不均匀性,在靠近小机排汽侧的出口截面又形成了两个局部低速区。小机排汽量从额定工况不断增加时,喉部的能量损失系数减小;反之,喉部的能量损失系数增大。小机排汽的入口位于低加以下时,排汽对喉部出口流场的影响较小,能量损失系数减小。该研究对于凝汽器喉部的完善化设计及改造具有一定的指导意义。 相似文献
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壳侧入口流动条件的给定会影响凝汽器壳侧流场的数值模拟结果,为进一步改进凝汽器性能的分析手段,以两台电站凝汽器为对象,分别在壳侧入口流场均匀分布和不均匀分布两种条件下对凝汽器壳侧的蒸汽流动进行数值模拟,其中不均匀入口条件基于对凝汽器喉部流场的模拟获得,进而通过数据提取获得两台凝汽器的性能曲线,并对不同入口条件下模拟得到的凝汽器性能进行了对比,模拟结果表明:凝汽器喉部出口流场具有较强的不均匀性;壳侧入口均匀条件下模拟得到的凝汽器性能好于入口不均匀条件,建议在研究凝汽器性能时尽可能地考虑入口蒸汽流场不均匀分布的影响。 相似文献
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《International Journal of Hydrogen Energy》2022,47(63):26789-26797
The issues related to the reliability of hydrogen engines of unmanned vehicles and increasing the efficiency of using hydrogen as fuel when using the method of its production during the decomposition of hydrogen-containing molecules of liquid-phase organic compounds in a plasma discharge under the action of intense ultrasonic exposure are considered. Experiments have shown that as a result of decomposition in the acoustoplasma discharge of liquid hydrocarbons, solid-phase carbon-containing products are formed, chemical transformations occur in the liquid phase and hydrogen-containing combustible gas is formed. Hydrogen-containing gas can be used as fuel immediately after synthesis, i.e. it does not require separation, since in addition to hydrogen it contains only impurities of CO2 and water vapor. The purpose of the study is to formalize the basic conditions for tightening the control of mutual compliance with the efficiency of hydrogen engines of the same series in the conditions of their mass production. Methods of mathematical statistics and hardware-software modeling were used in the study. The term “unerroric of quality mutual compliance control” is introduced to describe a set of hardware and software tools for such control. The principle of in-depth testing of the technical condition of such engines of one series is described in a multidimensional formulation of the quality control problem for three of their operating parameters at once. The conditions for increasing the mutual correspondence of the measured values of such parameters in the conditions of serial production of hydrogen engines are formalized. 相似文献
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世界发电燃料结构在不断的转换过程中。18世纪60年代从薪柴转到煤炭,19世纪到20世纪初大量发展燃煤电厂;20世纪20年代又从煤炭转向石油和天然气,20年代上半叶又大量发展燃油电厂;20世纪末由于天然气生产的发展,天然气因环境影响小,受到工业发达国家的青睐,加速发展天然气电厂。我国70年代初和90年代曾两次发展燃油电厂,由于石油危机和石油价格暴涨而受到制约,不得不实行以煤代油,改造燃油电厂。现在似乎认为燃油电厂不能再搞,但又出现发展燃气电厂的热流,发展燃气电厂确实是当今的世界潮流,但是同当年发展燃油电厂一样,要研究是否符合中国的国情? 相似文献
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本文从新型活塞设计的趋势及其对活塞车床的功能要求,讨论活塞车床的设计方案,并从机床功能、造型和宜人性上进行分析。 相似文献
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本文对漫灰均温物体在常物性条件下对外辐射传热的Yong值计算建立了数学模型。通过与物体内能Yong公式的数值计算比较,得出了辐射能量的Yong值不大于内能Yong值的结论。从初步的热射Yong值计算公式发现。Yong与物体表面辐射率有关。 相似文献