某重型燃气轮机DLN燃烧室数值模拟-热态分析

数值模拟是开展燃气轮机燃烧室性能分析的重要手段。本文通过外形3D扫描与内型工业CT扫描构建了某重型燃气轮机天然气DLN燃烧室的完整几何模型。通过对该完整三维建模进行高质量网格划分,并综合燃气轮机循环分析给出的工况参数,开展了数值模拟分析。本文热态模拟了燃烧室内流场、温度场及组分场,发现该型燃烧室喷嘴布置方式存在中心区域不能完全燃烧的风险。研究方法与结果可为燃气轮机DLN燃烧室的分析与设计提供参考。     

燃气轮机燃烧室三维冷态流场数值模拟

本文针对某燃气轮机环管型燃烧室三维冷态流场的数值模拟问题进行了研究。根据该型燃气轮机燃烧室的设计图纸建立真实的三维计算几何模型;在计算中采用SIMPLE算法,k-ε双方程湍流模型,对其进行了冷态空气流场的数值模拟;通过对各处流场分布的分析,特别是对主要区域各关键截面的流动分析,可以判断出燃烧室设计的合理性,为进一步优化燃烧室的结构设计、改善流场结构,并为开展燃烧室热态流场的数值模拟奠定了基础。     

重型燃气轮机燃烧室流动特性研究

为了探究燃烧室流动特性,为燃气轮机燃烧室设计改型、燃气轮机的安全稳定运行及合理的组织燃烧室流场提供参考依据,本文基于某重型燃气轮机分管型燃烧室,建立了预混燃烧模式下燃烧室三维数值仿真模型,采用数值模拟方法研究了燃烧室温度场、压力场、速度场以及主要组分浓度场的分布规律。结果表明:燃烧室旋流喷嘴下游中心区域为局部高温区,在喷嘴射流区存在低温区域,燃烧室中后部温度高于燃烧室头部温度;燃烧室头部压力较大,后部压力分布趋于均匀;燃烧室喷嘴及燃烧室头部区域,回流区域明显;旋流喷嘴附近NOx质量分数最大。     

掺混孔调整对燃气轮机DLN燃烧室性能影响研究

掺混孔是影响燃气轮机燃烧室出口温度分布的重要设计参数.针对多喷嘴DLN燃烧室开展整体数值计算,探讨了掺混孔尺寸调整对燃烧室性能的影响规律.研究表明,减小掺混孔一方面可使进入燃烧室头部的空气量增多,燃烧峰值温度和平均温度显著下降,有利于改善燃烧特性,另一方面削弱了掺混孔射流卷吸效应,使火焰筒金属壁面的高温区范围大幅缩小....     

某重型燃气轮机一级动叶气热耦合数值模拟

数值模拟是开展燃气轮机部件性能分析的重要手段,但是透平动叶工况与结构高度复杂,要开展完整全三维结构的气热耦合分析存在较大挑战。本文通过外形3D扫描与内型工业CT扫描获得了某重型燃气轮机透平一级动叶的关键几何数据,综合燃气轮机整体工况参数分析等相关信息,对一级动叶实现了完整的三维建模并进行了高质量网格划分,然后开展了单排动叶气热耦合数值模拟。计算获得透平气动效率较高,表面平均温度值比较合理,主要高温点也与透平实际烧蚀点比较吻合。相关结果可为透平动叶故障分析与设计改进提供参考。     

某型燃气轮机燃烧室燃烧流场数值研究

燃气轮机燃烧室的燃烧特性受到旋流强度、雾化特性等因素的强烈影响,旋流强度和雾化特性分析对燃烧室的设计和优化具有非常重要的作用。对燃气轮机燃烧室的燃烧流场,应用商用程序FLUENT进行了数值模拟,并分析了空气过量系数α和燃油雾化粒径对燃烧室内燃烧特性的影响。模拟结果表明,控制空气过量系数和燃油雾化粒径对提高燃烧室工作性能和降低污染物排放具有重要意义。     

燃气轮机燃烧室内部两相流动数值模拟与结构优化

针对燃气轮机低污染燃烧室内部流动的特殊要求，基于燃烧室完整真实几何结构进行三维的冷态模拟和两相流动模拟，分析内部的流动规律以及原始设计中存在的问题。通过改进燃烧室几何结构，得出更加合理的流场分布，从而指导燃烧室的结构优化设计。改进后的数值模拟结果表明：所采取的改进措施的效果明显，所建立的流动分析系统可以进行燃气轮机燃烧室的优化设计。     

生物质气微型燃气轮机燃烧室的数值模拟

将生物质气应用在为天然气设计的微型燃气轮机中时,由于其热值较低以及可燃成份的不同,会给燃烧室的温度场、速度场以及燃烧特性造成影响.对30 kW级微型燃气轮机的燃烧室进行了初步的设计,并在此基础上采用Fluent软件对燃烧室燃烧甲烷气和生物质气进行了数值模拟比较,探讨了燃烧生物质气对燃烧室内部流动、温度分布和NOx排放造成的影响及其原因,为今后生物质气微型燃气轮机燃烧室的设计应用提供了数据.     

燃气轮机燃烧室内NOx生成影响因素的数值研究

低NOx燃气轮机燃烧室的燃烧特性受到旋流的强烈影响，旋流特性的分析对燃烧室的设计和优化具有非常重要的作用。本文对燃气轮机燃烧室的旋流燃烧流动，应用商用程序FLUENT进行了数值模拟，并分析了旋流数、压强、湍流度对燃烧室内燃烧特性和NOx生成特性的影响。模拟结果表明，随着压强的增加，NOx排放逐渐增加，随着燃料入口湍流度的增加，NOx排放将减少，而随着旋流数的增加，NOx排放先是增加而后减小，同时，NOx随压强变化呈指数规律变化，但不同的燃烧组织形式对指数值有较大的影响。     

微型燃气轮机燃烧室性能的数值研究

针对Capstone公司的C30微型燃气轮机的燃烧室，采用κ—ε湍流模型、EBU—Ambenius湍流燃烧模型描述其燃烧流动，采用扩展Zeldivch机制描述HOx生成；应用分区结构化网格和SIMPLE算法求解控制方程，进行了三维燃烧流动的数值模拟研究，同时对燃烧室的整体性能进行了分析。通过数值计算及结果分析，着重研究了环型贫燃预混燃烧室的燃烧组织形式对燃烧室性能的影响，并探讨了流动控制板对燃烧室内燃烧流动和燃烧室出口HOx分布的影响。数值研究的主要目的是配合新型微型燃气轮机的研制，获得微型燃气轮机燃烧室的设计经验，为研制既有高燃烧效率和燃烧稳定性，又有低HOx排放特性的燃烧室奠定基础。     

小型锅炉烟尘测试时锅炉出力的计算

锅炉烟尘测试时,必须对锅炉出力进行测试。但监测中,许多小型锅炉往往不具备相关的计量装置和仪表,为解决这一问题,文章提出了用烟气量和空气过剩系数来计算锅炉的出力的公式,在实际使用中,该方法简单易行,其结果和实测值具有很好的一致怀。     

Unerroric of control of mutual compliance of the efficiency of hydrogen engines of unmanned vehicles in the conditions of mass production

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.     

中国煤炭地下气化技术的发展

本文综述了煤炭地下汽化技术的国内外发展现状,对我国“长通道、大断面”煤炭地下气化新工艺给予了技术经济评述,并提出了发展煤炭地下汽化技术的政策建议。     

Review of theory of distortion and disintegration of liquid streams

Linear and nonlinear analyses of the instabilities and distortion of liquid streams injected into a gaseous media are discussed. The various fundamental mechanisms and the predictive capabilities for the distortions are emphasized. Round jets, planar sheets, annular sheets, and conical sheets are discussed in detail. The balance between capillary and inertial forces is primarily examined. The method for simplifying the analyses in the case of thin liquid sheets is discussed. The capabilities for representing the droplet size distribution that follows the stream disintegration are outlined.     

MgO膨胀剂细度对MgO水化和水泥浆体膨胀的影响

基于《水工混凝土掺用氧化镁技术规范》中的Ⅰ型氧化镁（MgO）,研究了该型MgO膨胀剂（MEA）细度对掺粉煤灰水泥浆体膨胀性能的影响。即采用X射线衍射分析(XRD)及同步热分析（TG DSC）分析了掺MEA水泥浆体中MgO的水化性。结果表明,养护温度相同时,MEA的细度对水泥浆体内MEA中MgO的水化和水泥浆体的膨胀无显著影响,产生的膨胀均能补偿水泥浆体的收缩;MEA的细度可从试验设计采用的45 μm筛筛余15%左右增加到30%左右,这将有利于MEA生产企业的节能降耗。     

机车车轮多轴疲劳强度安全评定的研究

使用ANSYS8.0软件对高速列车车轮进行了三维有限元分析,计算出车轮在直线、曲线和道岔条件下牵引、制动共6种工况时孔边薄弱部位的应力,分别通过Mises等效平均应力方法、Sines平均主应力方法和应力分量中考虑平均应力方法计算出应力在极值位置时的等效应力幅、等效平均应力,从而进一步算出车轮的安全系数,对其疲劳强度进行评定,并对3种方法进行了比较研究。     

Constructal optimization of the geometry of an array of micro-channels

This paper documents the geometric optimization of an array of circular and non-circular ducts. The optimization was carried out numerically using finite volume method. As optimal dimensions were independent of the array configuration, the numerical simulation was performed on a unit cell. Numerical optimization for circular, square and isosceles right triangle cross-sections of channels was performed. Based on the results of this investigation, some correlations were proposed to predict the optimal hydraulic diameter and dimensionless heat transfer per unit volume. In addition to examining the effect of pressure drop on these parameters, it was showed that among the different geometries of this study, square cross-section has the most efficiency for a given volume. The numerical results of the present study were compared with approximate results reported in the literature which a good agreement was observed.     

固体热辐射Yong性能分析

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。     

Measurements of concentration distribution of hydrogen jet using deflection of center of the laser spot

The main purpose of this work is to propose a new method to evaluate the concentration distribution of the hydrogen jet by using a He–Ne laser through the jet. This research attempts to apply the expression of concentration Gaussian distribution, the refraction formula of inhomogeneous refractive index medium, and the concentration inversion function to disclose the displacement of the center of the laser spot at different heights in the gas jet. The spot images of the laser beam passing through the gas jet at three vertical heights z = 10d, 20d, 30d, and different radial positions are obtained. The radial spatial asymmetry of the gas jet is also found in the experiment. Finally, the calculated concentration distribution curve and the fluent simulation curve, it is found that the two results are very similar. Our findings show that the error between the concentration distribution of this method and the simulated concentration distribution reaches 2.43%.     

Heat of vaporization of mixtures

General expressions for the heat of vaporization of mixtures at constant pressure; at constant temperature; and at constant pressure, temperature, and composition are proposed. The last one is related to the liquid-vapor interface where steady vaporization or condensation is taking place. Numerical examples by the proposed expressions are shown for binary mixtures of HCFC22(R22) and (HCFC123(R123) © 1997 Scripta Technica, Inc. Heat Trans Jpn Res, 25(1): 12–24, 1996