BCS技术在大型圆环形竖炉上的应用

介绍“通用燃烧优化控制技术（BCS）”在大型圆环形竖炉上的应用。由于煤气压力和热值的波动大,燃烧过程难以控制,采用BCS技术,可使适于竖炉工艺要求的空、煤气配比达到最佳,优化了燃烧过程,使竖炉的生产能力得到充分发挥,节约了大量煤气,创造了可观的经济效益。     

煤气、石油气喷嘴和燃烧器应用研究动态

能源问题举世瞩目,研制、推广高效用能设备,对燃烧过程进行分析检测是节能的重要措施.1985年以来,我省一些产业部门不断从国外引进煤气喷嘴及燃烧器,例如日本高砂工业株式会社煤气燃烧器,意大利维高公司煤气燃烧技术及西德AGROB 公司的煤气燃烧器等.一些单位正在仿制,但燃烧效率普遍比进口的燃烧器低,耗气量大15～30%.燃烧过程是喷射流体引射空气两次进风紊流掺和,伴随着质、热传递,流场结构极     

氧化铝回转窑火焰图像处理与特征提取

在烧结法生产氧化铝过程中，为监控回转窑内部燃烧状况，提高熟料质量，采用了数字图像采集与图像处理的方法，并通过对燃烧火焰和烧成熟料图像的数据分析与平滑滤波，得到了火焰强度和熟料等级两个数字化特征值，为回转窑的操作优化和自动控制提供了可靠的依据。     

煤气燃烧器喷射流体紊流方程及其封闭条件

煤气燃烧过程是喷射流体抽吸空气两次进风紊流掺和、伴随着质、热传递的过程,流场结构极其复杂,燃烧器混合流场的理论研究包括:①从喷嘴出发,一次及二次进风紊流混合过程;②二次进风后煤气与空气在热管的混合;③炉头混合气体的燃烧过程.本文着重研究前两部分,介绍紊流方程组及其封闭条件,并讨论其应用前景.煤气燃烧喷射流体从喷嘴喷出,为有限空间约束射流,由于流速较低,喷射流体和经过两次进风进入热管至炉头前的混合流体.可假设为①是不可压缩的;②稳定轴对称流动;③流     

高炉煤气锅炉燃烧控制策略分析

通过分析高炉煤气锅炉燃烧的工艺要求,提出了保证高炉煤气锅炉炉膛安全运行和经济燃烧的控制策略,希望对相关行业的发展有所帮助.     

蓄热式加热炉内NOx生成的数值模拟

目前蓄热燃烧技术已经在加热炉上广泛应用,但NOx生成机理仍不很清楚。本文以鞍山热能研究院建造的蓄热式加热炉为原型,对低热值煤气蓄热燃烧过程进行了数值模拟。通过比较不同预热温度、不同空气系数、不同空气喷口倾角和不同煤气与空气喷口间距,发现当这些条件改变时,低热值煤气燃烧过程的NOx生成量也随之发生变化。     

工业窑炉燃气污染控制的相关问题讨论

控制大气污染的重要手段之一是对燃烧过程加以优化控制.文中,在分析产生污染原因的基础上,指出恰当的空气燃气比是保证充分燃烧的关键,并以轧钢加热炉燃烧过程控制为例,简要讨论了复杂燃烧过程的对象特性、可供选择的控制策略和优化的控制算法.成功的工程实践表明,只要对燃烧过程进行优化控制,废气污染是可以消除的.     

基于Simulink的含钒页岩提钒回转窑燃烧系统控制方法的研究

本文就含钒页岩提钒回转窑燃烧系统中烧成带温度的控制进行了研究。首先根据回转窑的燃烧数据,通过Matlab中的系统辨识功能,得到烧成带温度控制的传递函数。其次分析比较了常规PID控制方法与Fuzzy-PID控制方法,并分别采用这两种方法对燃烧系统进行了Simulink仿真分析。仿真结果表明,回转窑燃烧系统采用Fuzzy-PID控制方法能够更有效的实现对烧成带温度的恒定控制,并具有更强的抗干扰性能。     

氧化球团回转窑拖轮轴瓦刮研及调整找正技术研究

本文通过现场实际操作经验,对回转窑安装过程中关键环节拖轮轴瓦刮研、调整找正技术进行探讨,进一步提出并优化现有回转窑拖轮安装方案。     

新型矿用热风炉火焰监控系统的设计与实现

针对新型矿用热风炉燃烧控制的实际需求,设计了一套火焰监控系统.该系统可以很好地识别火焰燃烧状态,并根据不同的火焰状态对煤气阀门进行相应地调节,以保持系统相对正常的燃烧,大大减少了操作人员地劳动强度,提高了燃烧效率.     

基于模型控制的9FB燃气轮机燃烧调整技术探讨

燃烧调整是燃气轮机关键技术之一,对抑制燃烧脉动、保证稳定运行、降低排放有着重要的意义。本文主要介绍9FB燃气轮机燃烧脉动监测系统,基于模型控制的基本原理及其在燃烧调整中的应用,燃料阀分量计算方法,以及在实际工程中案例分析及解决过程。     

Biparametric assessment of the combustion stability in an industrial gas turbine combustor

Here we propose a generalized procedure for a two-parameter assessment of the Combustion stability (CS) of industrial gas turbines. In evaluating the CS, this procedure employs two parameters of measured dynamic pressure data: the Root-mean-square (RMS) pressure as the primary parameter and the damping ratio as a secondary parameter. The former tells the time-averaged level of the dynamic pressure, and, the latter, the degree of acoustic energy loss. A data point pairing the two parameters, which are evaluated at a specific instance of a combustion process, identifies Instantaneous combustion stability (ICS) by its location on a 2-D domain of both parameters. Collective representation of the ICS points on the domain produces a CS map of the combustion process. The locus of the ICS point on the map represents the temporal variation of CS during the combustion process. The biparametric assessment procedure divides the CS map into three regimes (i.e., stable, transitional and unstable) by utilizing two threshold values for the RMS pressure and one for the damping ratio. The feasibility of the proposed procedure was tested with the dynamic pressure data from a model gas turbine combustor burning synthetic natural gas. Then the technique was applied experimental data obtained from a laboratory-scale lean premixed combustor to identify the three regimes of the combustion process of a reported case. We found that the procedure is able to provide gas turbine operators with valuable information on CS during a combustion process, especially on the transitional regime.

     

动力锂离子电池热失控燃烧特性研究进展

频发的电动汽车火灾事故引起了对动力锂离子电池燃烧特性与火灾消防的日益重视。在动力锂离子电池起火燃烧演进的三阶段划分中,首先是外部滥用条件引发了动力锂离子电池内部材料化学反应的自我加速过程,随着化学反应放热累积和产气气体增加,导致在一定的压力下动力锂离子电池进入释放阀打开进入泄气过程,最后释放气在多种着火源引导下进入起火燃烧过程。事实上,在动力锂离子电池的热失控燃烧过程中,这三个阶段并非完全割裂,是一个复杂的并列发生现象。与传统的火灾相比,动力锂离子电池的燃烧有其特殊性,如燃烧受控条件涉及化学反应释放的热量、动力锂离子电池电能内短路后转化生成的热量、动力锂离子电池材料体系中的可燃成份、动力锂离子电池泄气中易燃气体组成等。综述动力锂离子电池热失控的演化进程、泄气的组分与浓度及毒性、动力锂离子电池单体和模组的燃烧放热量和放热速率以及燃烧过程的质量损失等燃烧特性、电池包的火灾蔓延特点与灭火剂筛选原则。针对动力锂离子电池火灾的机理及特点,总结现有研究中存在的不足、可能的改进措施以及研究尚未涉及的关键研究点。     

Analysis of the combustion oscillation in a silo-type gas turbine combustor and its suppression

The characteristics of combustion oscillation of a silo-type 79.5 MW gas turbine combustor in commercial operation and its suppression have been investigated. The oscillation of the lean premixed gas turbine combustor resulting from the combustion instability occurred at near full load operation. An FFT analysis of the combustion dynamics showed that the dominant frequency of the oscillation would be that of the 1st longitudinal acoustic resonance mode of the combustor. To suppress the combustion oscillation, a passive control technique for reducing the combustion instability was employed; that is, the fuel to the combustor was redistributed by adjusting the operational schedule of one of six fuel control valves, which would lead the increase of the local operational equivalence ratio near the central recirculation zone of the combustor. By doing so, the oscillation was successfully reduced to the permissible level while the amount of NO_x emission met proper regulatory level set by the local government.     

An experimental study on combustion efficiency of low grade anthracite in AFBC

This is the basic study to develop a fluidized bed combustion boiler which can use low grade anthracite. In this study, the anthracite of about 3400 kcal/kg was burned in the bench scale non-recycling atmospheric fluidized bed combustor of 200mm diameter and 2215mm height with the static bed height of 250mm and the combustion temperature range of 800–950°C. During the combustion, the effect of factors such as the superficial gas velocity in bed, the air ratio, the coal supply location and the coal particle size on the combustion efficiency, the elutriation ratio and the unburned carbon content both in elutriated ash and in drained ash was thoroughly analyzed. When the superficial gas velocity in bed is 0.7～2.2m/s, the air ratio is 1.0～1.6 and coal supply locations are 300,500 and 700mm above the air distributor, the combustion efficiencies range from 66% to 83.5% for the mean coal particle size of 0.209mm, and from 71% to 88% for the case of 0.265mm. The combustion efficiency decreases as the superficial gas velocity in bed and the air ratio increase. The lower the coal supply location is, the better the combustion efficiency becomes in general.     

微自由活塞发动机HCCI着火界限研究

开展微燃烧室里均质压缩燃烧(Homogeneous charge compression ignition,HCCI)可视化试验,进行定性分析,并以试验为基础建立三维数值模拟计算模型;基于丙烷燃烧化学反应动力学机理,提出自由活塞运动与燃烧过程耦合的计算方式,通过编写STAR-CD软件中的动网格子程序,对微燃烧室里均质气体压缩燃烧过程进行了数值模拟研究;分析了各种参数对微HCCI着火特性的影响,得出在理想模型下的压缩着火界限,即当量纲一参数压缩比不小于55时,均质气体总能压缩着火;并揭示泄漏对均质压缩燃烧过程的影响,得出在不同泄漏间隙尺寸下着火界限的变化情况,为微自由活塞发动机的设计提供一定的理论依据。     

300MW机组燃烧控制系统的改进

以华能杨柳青电厂8号300MW单元机组为例,针对其锅炉燃烧效率较低,燃烧控制系统逻辑及其相关参数随着机组的长期运行已不能很好的满足控制要求等诸多问题,对8号单元机组燃烧控制逻辑及其参数进行了优化,增加了煤质校正回路,并对烟气含氧量测量、等离子点火技术、磨煤机就地控制等相关设备进行了改进。8号机组在投入协调控制方式运行后的结果表明,通过对燃烧控制系统中控制逻辑和现场设备的优化改进,机组燃烧效率以及机组主要运行参数都达到了令人满意的水平;而且通过对此次优化改进,也取得了减少机组污染物排放的效果。     

基于黑箱模型和RBF-PID的HCCI发动机燃烧正时控制

由于均质充气压缩点燃(HCCI)发动机缺少直接控制其燃烧的手段,导致HCCI发动机的燃烧正时控制成为HCCI发动机的研究热点。以HCCI发动机进气歧管的温度和压力、燃油当量比、转速以及进气门关闭正时为输入,利用BP神经网络建立用于估计HCCI发动机燃烧正时的黑箱模型。在此模型基础上,以进气门关闭正时为控制量设计了PID控制器,并利用径向基神经网络对其参数进行整定,以实现对燃烧正时的反馈控制。实验结果表明,BP神经网络估计模型对HCCI发动机燃烧正时的估计误差小于0.4(CAD),能实现准确的估计;此外,与传统的PID控制器相比,设计的RBF-PID控制器在超调量、调节时间以及抗干扰性等性能方面均有改善。     

点燃式天然气发动机燃烧室结构优化的仿真与试验研究

利用三维数值仿真的方法,对带有浴盆形燃烧室的天然气发动机缸内流动和燃烧特性进行分析,提出了两种燃烧室结构优化设计方案,试验对比了采用原燃烧室和挤气喷射燃烧室时的发动机性能。结果表明:在不改变压缩比情况下,通过改变活塞头部凸起形状和位置,能够实现浴盆形燃烧室内的挤流与滚流有效耦合;控制点火时刻的火花塞附近气体流速,能提高缸内平均湍动能,加大快速燃烧期内火焰前封面的面积,改善燃烧质量。发动机采用优化的2号挤气喷射燃烧室,能够明显加快发动机燃烧进程,提高发动机的动力性和经济性,发动机功率从75kW提高到78.7kW,最低比气耗降低4.4%,HC和CO排放略有降低。     

An experiment analysis of MILD combustion with liquid fuel spray in a combustion vessel

Mild combustion is characterized by its distinguished features, such as suppressed pollutant emission, homogeneous temperature distribution, reduced noise, and thermal stress. Recently, many studies have revealed the potential of MILD combustion in various power systems but most studies have been focused on gas phase fuel MILD combustion. Therefore, further study on MILD combustion using liquid fuel is needed for the application to a liquid-fueled gas turbine especially. In this work, we studied experimentally on the formation of liquid fuel MILD combustion under the condition of high dilution by burnt gas generated from a first premixed flame in two stages combustor which consists of the first premixed burner and secondary combustor. In particular, the effects of burnt gas velocity and oxygen level of burnt gas on the formation of liquid fuel MILD combustion were investigated. The results show that as the burnt gas velocity through the nozzle becomes higher, the color of flames was changed from yellow to pale blue and flames became very short. The OH radical measured by ICCD camera was uniformly distributed on the pale blue flame surface and its intensity was very low compared to conventional liquid diffusion flame. As burnt gas velocity is increased, local high-temperature region appeared to be diminished and the flame temperature became spatially uniform. And CO emission was sampled around 1 ppm and NOx emission was measured around 10 ppm under the overall equivalence ratio of 0.8 to 0.98 for 40 mm or less diameter of velocity control nozzle. This low NOx emission seems to be attributed to maintaining the average temperature in secondary combustor below the threshold temperature of thermal NOx formation. In view of the uniform temperature distribution, low OH radical intensity and low NOx emission data in the secondary combustor, formation of stable MILD combustion using kerosene liquid fuel could be verified at high burnt gas velocity.