• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Numerical simulation of hydrogen/air mixing for next-generation lean premixed gas turbines.
【24h】

Numerical simulation of hydrogen/air mixing for next-generation lean premixed gas turbines.

机译：下一代稀薄预混燃气轮机氢气/空气混合的数值模拟。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In recent years, hydrogen has garnered the attention of the combustion research community as fuel for a new generation of clean power generation technologies, for its advantages such as precluding the emission of greenhouse gases and limiting the emission of criteria pollutants to nitrogen oxides (NOx). The major product of the hydrogen combustion is water and, under proper control, the emission of NOx can be substantially reduced.;To achieve low NOx emissions in hydrogen gas turbine, lean premixed combustion can be employed in conjunction with a properly designed premixer. However, the properties of hydrogen present unique challenges in the design of a premixer.;Numerical simulation can increase the understanding of the mixing processes and guide the design of premixers. With sufficient accuracy, such simulations may be able to effectively "screen" designs. For screening, efficient simulation strategies are desired. At the same time, the unusually high diffusivity of hydrogen and anisotropy associated with micro-mixing which may pose special challenges to any such numerical simulation. The goals of this dissertation are to delineate an understanding of hydrogen/air mixing in advanced premixers, and provide guidance in the design of premixers that (1) minimize the formation of NOx, and (2) minimize the initiation of flashback and/or autoignition. The focus is on the evaluation of the accuracy of the hydrogen mixing prediction with various types of Computational Fluid Dynamic (CFD) models. In particular, current CFD methodologies are thoroughly studied, sensitivity studies on various factors are conducted, and simulation results are compared to experimental data. Finally, conclusions and recommendations for hydrogen mixing in premixers are presented.;It is found that the anisotropy associated with the highly turbulent elliptical flow in advanced gas turbine premixing micro-mixers creates demanding challenges for numerical methods. The unusually high diffusivity of hydrogen further challenges the adequacy of traditional and state-of-the art simulation methodologies and turbulent models to adequately describe key features of the mixing process. While adjustments can be made (e.g., a reduction in turbulent Schmidt Number) to more adequately describe trends and guide incipient designs, a more robust approach will require, at a minimum, a flexible turbulent Schmidt number approach.
机译：近年来，氢作为一种新型清洁发电技术的燃料已引起了燃烧研究界的关注，氢的优势包括可以避免温室气体的排放以及限制标准污染物向氮氧化物（NOx）的排放。 。氢燃烧的主要产物是水，在适当的控制下，可以大大减少NOx的排放。为了在氢气涡轮机中实现低的NOx排放，可以将稀薄的预混燃烧与经过适当设计的预混合器结合使用。然而，氢的性质在预混合器的设计中提出了独特的挑战。数值模拟可以增加对混合过程的理解，并指导预混合器的设计。以足够的精度，这样的模拟可能能够有效地“筛选”设计。为了筛选，需要有效的模拟策略。同时，与微混合相关的异常高的氢扩散率和各向异性可能对任何此类数值模拟构成特殊挑战。本文的目的是描述对高级预混合器中氢气/空气混合的理解，并为预混合器的设计提供指导，以（1）最小化NOx的形成，（2）最小化回火和/或自燃的开始。重点是使用各种类型的计算流体动力学（CFD）模型评估氢混合预测的准确性。特别是，对当前的CFD方法学进行了深入研究，对各种因素进行了敏感性研究，并将仿真结果与实验数据进行了比较。最后，给出了在预混合器中进行氢混合的结论和建议。发现在先进的燃气轮机预混合微混合器中，与高度湍流的椭圆流有关的各向异性给数值方法带来了严峻的挑战。氢气异常高的扩散率进一步挑战了传统的和最先进的模拟方法和湍流模型是否足以充分描述混合过程的关键特征。虽然可以进行调整（例如，减小Schmidt湍流数）以更充分地描述趋势并指导初期设计，但更可靠的方法至少需要灵活的Schmidt湍流数法。

著录项

  • 作者

    Wang, Qing.;

  • 作者单位

    University of California, Irvine.;

  • 授予单位 University of California, Irvine.;
  • 学科 Engineering Mechanical.
  • 学位 Ph.D.
  • 年度 2009
  • 页码 134 p.
  • 总页数 134
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 机械、仪表工业;
  • 关键词

  • 入库时间 2022-08-17 11:38:28

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号