全氧燃烧浮法玻璃熔窑窑压的数值模拟

采用基于k-ε湍流模型、涡-耗散化学反应模型、P1辐射传热模型的数值模拟方法,研究了玻璃熔窑在全氧燃烧条件下烟气出口面积对窑内压力场和火焰空间的影响规律。研究结果表明,所选用的三维数学模型能够较为真实的反应全氧燃烧玻璃熔窑火焰空间的状态。随着烟气出口面积的增加,玻璃熔窑内压力下降,窑内平均压力与烟气出口面积符合指数衰减关系。当单侧烟气出口面积为0.36 m2时,窑内平均压力约为6 Pa。烟气出口面积改变对火焰形态以及温度场的影响不明显。因此改变烟气出口面积可以作为有效调节全氧燃烧浮法玻璃熔窑窑内压力技术手段,这为指导全氧燃烧玻璃熔窑的设计和运行提供了理论依据。     

玻璃熔窑富氧燃烧的几个关键问题

富氧燃烧技术是一项节能新技术，文章对玻璃熔窑中的富氧燃烧系统的几个关键问题进行探讨，为玻璃熔窑合理使用富氧燃烧技术以取得较好的节能效果进行可行性建议。     

全氧燃烧喷枪火焰空间气流场温度场的数值模拟

利用数值模拟方法,选用标准k-ε湍流模型、涡一耗散化学反应模型、p1辐射传热模型,研究了玻璃熔窑在全氧燃烧条件下助燃气体氧含量对喷枪火焰空间气流场和温度场的影响规律.结果表明,进油口尺寸、重油蒸汽速度和进气口尺寸一定.增大助燃气体氧舍量,有助于提高燃烧速率,使得尾气排放量及其带走热量减小.火焰空间温度场分布梯度变大.火焰温度增高.结果表明,所选用的三维数学模型能够比较全面地反映火焰空间气流场、温度场分布规律,这对于全氧燃烧在玻璃熔窑中的应用和研究,特别是氧枪的设计与操作,工艺制度的优化具有一定的理论和实践意义.     

浮法玻璃熔窑全氧助燃技术能耗分析

玻璃熔窑是玻璃生产中重要的耗能设备,文中介绍了某浮法玻璃生产企业通过采用全氧助燃技术,对该厂玻璃熔窑实施改造。并对玻璃熔窑实施全氧助燃技术改造前后的运行能耗数据进行了对比分析,实践证明采用全氧助燃技术在浮法玻璃生产企业应用切实可行,节能效果和节能经济效益显著。     

玻璃熔化炉用氧燃烧技术的开发

氧燃烧技术在高温工业炉领域的应用有助于大大削减NOx,C仇等有害气体的排放和提高炉子的热效率,改善工作环境,节能。近年来,由于氧气生产成本的降低,氧燃烧技术已开始涉人以玻璃熔化炉为首的工业炉领域.扼要阐述了氧燃烧技术的国际研究开发.重点介绍了玻璃熔化炉用天然气一氧烧嘴的开发、实验方法、实验结果,以及玻璃熔化炉氧燃烧的模拟与环保效果。照2图10参2玻璃熔化炉用氧燃烧技术的开发@陈留根     

水煤浆的强化燃烧技术及其工业应用

通过简化水煤浆的燃烧模型,计算了水煤浆的燃烧时间,分析了影响水煤浆燃烧效率的因素,提出了改善水煤浆燃烧效率的途径,并介绍了国内首次在玻璃熔窑上进行的水煤浆燃烧应用试验。     

不同富氧含量玻璃熔窑火焰空间温度场的对比

建立了玻璃熔窑火焰空间温度场的三维数学模型，通过对某日产400t燃油浮法玻璃熔窑火焰空间在三种富氧情况(氧含量分别是24％，27％，30％)下用图像模拟直观的表述出计算结果。模型包括气相流动与传热模型，雾化油滴燃烧的轨道模型，和辐射传热模型。程序采用MS-FORTRAN语言，绘图采用Stanfordgraphic软件。对比结果表明，随着富氧含量的增加，各小炉火焰长度明显缩短，温度显著提升，模拟结果对窑炉设计与富氧燃烧组织有一定的参考价值。     

燃天然气浮法玻璃窑炉的三维数值模拟

建立了具有实用意义的浮法玻璃熔窑三维数学模型，将火焰空间燃烧模型、配合料熔化模型、玻璃液流动模型进行耦合计算，求解出玻璃熔窑火焰空间、玻璃液流的温度场、速度场分布及配合料堆的长度分布。以日产400t的燃天然气浮法玻璃熔窑为对象研究了其火焰空间内气体、窑池内玻璃液的流动情况及各自的温度场分布。从模拟结果可以看出，该三维耦合数学模型能够比较客观地反应燃天然气浮法玻璃熔窑的速度场和温度场的分布规律，对燃天然气浮法玻璃熔窑的设计和运行具有一定的实用价值。     

浅谈全氧燃烧技术在玻璃工业中的应用

简要介绍了全氧燃烧的机理、优点、发展历程及应注意的相关问题,该技术不仅能节省大量能量,改善玻璃质量,而且还使燃料燃烧产生的氮氧化物得到根除,对环境保护也起到积极的作用。     

蓄热式富氧燃烧技术的实验研究与模拟分析

富氧燃烧作为高温燃烧技术的一种,在现有的玻璃、冶金工业和热能工程领域应用广泛。为了进一步提高燃烧温度同时节约能源,研究分析了蓄热式燃烧技术与富氧燃烧相结合的燃烧方式。对蓄热式富氧燃烧技术的各自燃烧特点进行对比分析。采用CFD工程模拟软件FLUENT模拟工况下燃烧。通过模拟与实验结果相对比,得出氧浓度对炉内燃烧以及温度的影响;同时得出该情况下能耗降低。研究结果表明该技术不仅提高温度,降低运行成本,而且能够使适用范围更加广泛。     

横火焰玻璃窑炉燃烧空间流动与传热的数值模拟

对横火焰玻璃窑炉燃烧空间内的流动、燃烧及辐射传热等过程进行了数值模拟研究,建立了玻璃窑炉燃烧空间内的综合数学模型,给出了诸控制方程的统一的数值解法,得到了炉内燃烧空间的速度场、温度场、组分浓度分布及燃烧空间向玻璃液面传递的热流分布。     

马蹄形火焰玻璃熔窑燃烧空间流动与传热的数值模拟

对马蹄形火焰玻璃窑炉燃烧空间内的流动、燃烧及辐射传热等过程进行了数值模拟研究,得到了炉内燃烧空间的速度场、温度场、组分浓度分布及燃烧空间向玻璃液面传递的热流分布。探讨了燃烧空间入口的进气角度对炉内温度场和向玻璃面传递的热流的影响,模拟结果表明,当入口的进气角度在5°～10°之间时,传热效果较好。     

富氧燃烧烟气焓温特性分析

针对富氧燃烧锅炉增加了尾部再循环烟气和空气分离单元抽取的氧气特点,比较了常规空气燃烧锅炉焓温表计算方法与富氧燃烧方式下焓温表计算内容的区别,分析了富氧燃烧锅炉循环烟气焓、分离氧气焓和炉膛进口热燃烧气焓随氧气的体积分数变化的特性,给出了富氧燃烧锅炉烟气焓温表的计算方法,为富氧锅炉热力计算提供了理论依据.     

Sensitivity analysis of skeletal reaction mechanisms for use in CFD simulation of oxygen enhanced combustion systems

Oxygen enhanced combustion (OEC) techniques are supposed to be a fuel saving alternative to conventional air-fired combustion, due to the reduction or removal of nitrogen from the combustion system, which causes a higher flame temperature and radiation intensity. Therefore, more heat is available in OEC for heating, melting and annealing processes, and subsequently, increases the process efficiency. The main aim of the present study is the numerical investigation of different reaction mechanisms under air-fuel and oxy-fuel conditions using 1D simulation of laminar counter-flow diffusion flames. The mechanisms are further used in 3D CFD simulation with the steady laminar flamelet model for the development of a time efficient numerical approach, applicable in air-fuel and OEC. Three skeletal reaction mechanisms were tested and compared to the GRI3.0 mechanism. The calculated temperatures and species concentrations revealed that a skeletal mechanism with 17 species and 25 reversible reactions predicts a faster fuel conversion into the reaction products under oxy-fuel conditions, which leads to higher temperatures in the flame compared to the GRI3.0. Sensitivity analysis showed that two reversible reactions are mainly responsible for the faster fuel conversion. Furthermore, the reaction mechanisms investigated, were used for 3D CFD simulation of a lab-scale furnace under different OEC conditions and air-fuel combustion. Up to concentrations of 30% O₂ in the O₂/N₂ mixture, all reaction mechanisms were able to predict the temperatures in the furnace with a close accordance to measured data. With higher oxygen enrichment levels, only the mentioned skeletal mechanism with 25 reactions calculated good results, whereas the GRI3.0 failed for oxy-fuel combustion.     

Modelling of the process of coal dust combustion in a cyclone furnace

This study presents the concept of a cyclone furnace for coal dust oxy-fuel combustion and gasification.The results of numerical calculations for the combustion and gasification processes were also presented.     

Eulerian approach for multiphase flow simulation in a glass melter

A glass furnace, consisting of a combustion space and a glass melter, uses combustion heat to melt sand and cullet into liquid glass to make products. Glass quality is mainly dependent on the temperature, glass composition, and the level of impurities in a glass melter, which include solid batch/cullet particles, liquid glass, and gas bubbles. A comprehensive computational model using an Eulerian approach has been developed to simulate multiphase flows in a glass melter. It includes all the phases, divides solid particles or gas bubbles into various size groups, and treats each group as a continuum. The derived mass, momentum, and energy conservation equations of the flow are solved for local properties for each phase. The simulation considers the heating and melting of the batch (mainly from the radiative heat from combustion and from the convective heat from the molten glass), the formation and transport of bubbles, and the heating and mixing of the liquid glass. The approach was incorporated into a multiphase reacting flow computational fluid dynamics code that simulates overall glass furnace flows to evaluate the glass quality and furnace efficiency.