1000MW超超临界双切圆锅炉烟温偏差的数值模拟

本文以1000MW超超临界双切圆锅炉为研究对象,通过数值模拟研究了炉膛内的燃烧、流场分布以及分隔屏间距对烟温偏差的影响。计算结果表明炉内温度场分布合理,气流形成较为完整的椭圆形切圆;炉膛出口烟气存在旋转残余,导致各屏间烟气温度与速度分布不均,靠近水冷壁区域烟气温度及速度明显低于炉膛中心侧;分隔屏可以促进烟气的均匀分布,因此调整分隔屏间距可以调节烟气量在分隔屏间的分配,有利于控制烟温偏差。     

炉膛中间截面边界条件对双切圆锅炉空气动力场计算的影响

大容量超超临界锅炉广泛采用单炉膛双切圆的空气动力组织方式,在计算流体力学软件FLUENT平台上,针对1GW超超临界单炉膛双切圆锅炉,计算了全炉膛和炉膛中间截面边界条件设为对称面和边壁条件的炉内空气动力场。计算表明,与标准κ-ε双方程模型相比雷诺应力模型(RSM)具有更高的计算精度;中间截面采用对称边界条件时,其流场分布规律与全炉膛模拟结果相似;中间截面为边壁条件时炉膛中间截面附近流速降低,但对整个炉膛流场影响较小;中间截面采用这两种边界条件均会导致1#、6#角射流衰减缓慢而冲刷炉膛前墙中间水冷壁。     

四墙切圆布置燃烧器炉内实际切圆大小的试验研究

在1MW实验台上分别对四墙切圆燃烧方式炉内冷态、热态实际切圆直径进行了测量,热态试验结果显示燃烧宜宾无烟煤时,一次风截面热态切圆直径为假想切圆直径的3倍;燃烧神木烟煤时,相同截面热态切圆直径为假想切圆直径的7.7倍,数据分析预示：冷态下沿炉膛高度切圆直径呈线性增大,热态下沿炉膛高度切圆直径呈波浪形增大。     

1000MW双切圆锅炉低氮同轴燃烧系统的模拟分析

以某电厂1 000 MW单炉膛双切圆锅炉为例,分析了炉膛内低氮同轴燃烧系统的流场特性。得到了单炉膛双切圆炉膛内温度、速度等物理量分布,得到了CFS(偏置风)、SOFA(分离燃尽风)对锅炉结渣性、烟温偏差、NO排放等的影响。结果表明:双切圆燃烧方式的烟速偏差小于单切圆燃烧方式;炉膛按温度分热角和冷角;受冷角布置的影响,适中的CFS风速才能形成"风包煤"特性,防止结渣;SOFA反切使受热面热偏差减小,火焰中心上移,NO浓度逐渐增大;SOFA摆角位置应根据受热面安全性、煤质特性、NO排放综合考虑。     

切向燃烧炉内实际切圆直径的回归分析

给出了切向燃烧锅炉炉内实际切圆直径的数学关联式,并用其对山东省内部分运行锅炉的实际切圆进行了预测,计算结果和实测数据的对比表明,该关联式能较为准确地预测炉内实际切圆的大小。     

四角切圆锅炉炉膛燃烧流场协同分析

采用空气分级燃烧和浓淡分离直流型燃烧器对某330MW四角切圆锅炉进行低氮改造,结合场协同原理对锅炉炉膛内的速度场、温度场、NOx浓度进行了分析。结果表明,切圆燃烧方式下,锅炉炉膛内的温度场和速度场在炉膛不同位置呈现不同的协同分布,协同角越小的区域,温度场和速度场协同性越好;沿炉膛高度方向上,协同角呈现波动的变化规律。燃烧器区域内温度影响NOx的生成,速度影响NOx迁移,炉膛上部结构对NOx分布影响较大。     

炉内辐射换热过程的有限体积法

简要分析了含吸收散射性介质的三维空腔内辐射传递方程的有限体积法求解过程,应用该方法对四角切圆炉膛内的辐射换热过程进行模拟计算,得出了炉膛内温度分布,并将计算结果与实测值进行了比较。通过数值计算表明：有限体积法计算速度快,对不规则边界适应性强,具有很高的工程可用性。     

能在线监督切圆燃烧炉膛工况的一维模型

本文为切圆燃烧炉膛的传热建立了一个一维区域模型。在模型中考虑了部分烟气由上而下回流的实际情况.此模型能够反映出沿炉膛高度方向热流和温度分布随炉内工况变化.文中还以1000t/h直流锅炉的双炉膛为例,在IBM-PC/AT机上进行了计算,结果准确,且计算过程极短,可用于锅炉的实时模型中。     

塔式炉膛烟气流动特性及非线性现象的数值和实验分析

为研究不同负荷超(超)临界塔式炉膛内燃烧及烟气流动的非线性特性,以某1 000 MW塔式炉膛为原型设计出几何结构和边界条件完全对称的三维简化锅炉模型,运用FLUENT软件模拟了锅炉在3种不同负荷(100%,75%和50%阀门全开工况(VWO))下炉膛内的速度场、温度场及NO_x的分布情况,并分析了非线性特性,最后建立了一个三维冷态切圆射流实验模型并进行验证,提出顺序启动的喷口启动方式。结果表明：不同负荷下,完全对称的炉膛内烟气流动速度、温度和组分分布均存在非线性现象,模拟结果得到关于模型几何竖直中心线不对称的解;喷嘴通过顺序启动方式可使切圆偏斜程度更小,流动形成的切圆能稳定在一个位置,实现流动的精准控制。     

四角切向燃烧煤粉锅炉炉内气固两相流动的数值模拟

本文运用非错列网格的SIMPLE方法和随机的颗粒轨道模型对四角切向燃烧煤粉锅炉炉内的气固两相流动进行了数值模拟，了解了实际切圆直径及气流旋转强度沿炉膛高度方向的变化规律，得到了不同粒径的煤粉颗粒在炉膛中的运动轨迹及浓度分布。与实验结果的对比表明本文所编制的程序能够较准确地模拟炉内的流动状况，计算所得的数值结果对四角切向燃烧锅炉的设计和运行都有着一定的指导意义。     

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.     

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。     

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。     

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     

生物质催化热裂解技术的研究进展

生物质催化裂解是生物质热化学转化的一种重要途径。综述了生物质催化热裂解技术使用的反应器、催化剂类型,以及催化热裂解过程中热裂解温度、吹扫气、升温速率、生物质原料等条件的影响,展望了生物质催化热裂解技术的发展趋势。     

燃烧流化床气泡能量分布模型

应用瞬态谱分析方法对燃烧流化床声波信号进行了频谱分析,发现气泡能量分布呈Ｇａｍｍａ分布形式,在Ａｒｇｙｒｉｏｕｓ和Ｙｏｓｈｉｄａ等人提出的模型的基础上,发展了燃烧流化床气泡能量分布模型,并通过优化迭代对模型参数进行求解,在实验和理论的基础上得出了更加切合实际的燃烧流化床气泡能量分布模型     

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.     

促进城镇生活污水处理装置产业化

城镇生活污水处理装置是由农村户用沼气地发展演变而来，是一种小型、分散化处理污水的装置 ，是环境建设的需要。文章着重从我国环保政策及目标、生活污水造成的污染状况、急需整治的公共设施、生活污水净化装置的演变以及社会经济效益和环境效益等方面，阐述了其产业化的重要性。     

Investigation of effect of variation of cycle parameters on thermodynamic performance of gas-steam combined cycle

The paper deals with second law thermodynamic analysis of a basic gas turbine based gas-steam combined cycle. The article investigates the effect of variation of cycle parameters on rational efficiency and component-wise non-dimensionalised exergy destruction of the plant. Component-wise inefficiencies of the combined cycle have been quantified with the objective to pin-point the major sources of exergy destruction. The parameter that affects cycle performance most is the TIT (turbine inlet temperature). TIT should be kept on the higher side, because at lower values, the exergy destruction is higher. The summation of total exergy destruction of all components in percentage terms is lower (44.88%) at TIT of 1800 K & r_p,c = 23, as compared to that at TIT = 1700 K. The sum total of rational efficiency of gas turbine and steam turbine is found to be higher (54.91%) at TIT = 1800 K & r_p,c = 23, as compared to that at TIT = 1700 K. Compressor pressure ratio also affects the exergy performance. The sum total of exergy destruction of all components of the combined cycle plant is lower (44.17%) at higher value of compressor pressure ratio (23)& TIT = 1700 K, as compared to that at compressor pressure ratio (16). Also exergy destruction is minimized with the adoption of multi-pressure-reheat steam generator configuration.