循环流化床气固两相流动的数值模拟_热能与动力工程.rar

  • 需要金币1000 个金币
  • 资料目录论文助手 > 大学本科 > 工业大学 >
  • 转换比率:金钱 X 10=金币数量, 例100元=1000金币
  • 论文格式:Word格式(*.doc)
  • 更新时间:2014-06-04
  • 论文字数:27779
  • 课题出处:(小婷)提供原创资料
  • 资料包括:完整论文

支付并下载

摘  要:循环流化床气固两相流数值模拟是通过建立数值模型以求更方便的研究循环流态化传热传质性质,从而用以加强循环流化床锅炉高效运作,提高能源利用率的技术。这种技术的推广与研究可以预测流场中的各种参数,再现流场的运动及变化特性,准确反映颗粒在外力作用下的受力及运动特征。因此,在循环流化床锅炉的研究和开发、尤其是大型化研究中,数值模拟成为一种不可或缺的研究方法和工具,具有重要的学术意义和实用价值。一个理想的循环流化床锅炉数值模拟应当包含对循环化床对气固相流颗粒进行了特点分析。

   再次,对气固两相流流化床锅炉系统的一系列物理过程和化学过程的模型描述。对试验而言,建模的投资要小得多,然而其通用性、灵活性和快速性却可以使锅炉设计者的设计建立在各种可能方案的充分比较、筛选和优化的基础上,其好处和经济效益是显而易见的。

   论文首先,对本课题的研究背景和立项意义进行了论述;简要介绍了循环流化床组成结构以及优点。

   其次,对多相流研究现状进行了综述。气固两相流的的基础理论进行了简要陈述,并结合循环流相流研究方法和气固两相流的主要参数进行了阐述。并且进行物理建模。其后详述了数值模拟所依托的fluent软件包。

   最后,对于气固两相流从原来的三类物理(对应于求解的数值模型)模型,即:连续介质模型、离散颗粒模型以及流体拟颗粒模型,侧重于离散颗粒模型,并在以后的设计中,利用欧拉—拉格朗日数学方法,将气固流态分为两种形式:一种是将空气场利用欧拉方法进行模拟;另一种是将流场利用拉格朗日方法进行模拟。并主要运用fluent软件进行简单颗粒的模拟计算简单的直筒流态化模型。

关键词:循环流化床  气固两相流   fluent  离散颗粒模型  欧拉—拉格朗日

 

Abstract:The numerical simulation of gas-solid two-phase flow on Circulating fluidized bed make a study of cycle fluidized heat and mass transfer properties according to  establish numerical model more conveniently ,in addition to strengthen the efficient of circulating fluidized bed boiler’s operations and improve the efficiency of energy technologies. This technology promotion and research can predict the various parameters flow field, reappearance the sports and variations of flow field, this way can reflect particles’ stress and movement characteristics in forces accurately. Therefore, during the circulating research and development of fluidized bed boiler in, especially Large-scale research, numerical simulation become a indispensable research methods and tools, has  an important effect on  academic value and practical value. An ideal circulating fluidized bed boiler in numerical simulation of circulating fluidized bed will contain gas-solid phase flow of the characteristic analysis particles.

   Next, we will describe a series of two physical processes and chemical process model of a gas-solid fluidized boiler system. As for test, modeling is much smaller, yet its commonality, flexibility and power makes boiler designers design based on various may plan fully comparison, screening and optimization, and on the basis of its benefits and economic benefits are obvious.

   Firstly, we will talk about the research background and significance of this subject; making a briefly introduction of the circulating fluidized bed’s structure and advantages.

   Secondly, do a review of multiphase flow. The foundation theory of Gas-solid two-phase are discussed briefly in the presentations, and combined with circular flow phase research methods and solid two-phase flow of main parameters is discussed in this paper. And also we will make a physical modeling. Thenceforth we will introduce the Fluent software packages which can support numerical simulation.

   Finally, there are three original physical model (corresponding to the solution of the numerical model) of gas-solid two-phase flow, namely: continuum model, discrete particle model and fluid fitting, stresses in discrete particle model particle model, and in the later design, use Euler - Lagrange mathematical gas-solid flow pattern is divided into two types: one kind is air field simulated using the Euler method; Another will flow field using Lagrange method is simulated. And using simple particles fluent soft software simulation calculation simple straight canister fluidized model mainly.

Keywords: circulating fluidized bed    gas-solid two-phase flow fluent   discrete particle model    Euler - Lagrange


支付并下载

提示:本站支持手机(IOS,Android)下载论文,如果手机下载不知道存哪或打不开,可以用电脑下载,不会重复扣费