基于多模型智能组合算法的锅炉炉膛温度建模

炉膛温度是表征锅炉燃烧状态的重要参数,但是影响炉膛温度的参数多、机理复杂,导致难以建立准确的预测模型。针对这一问题,提出一种多模型智能组合算法(multi-model intelligent combination algorithm, MICA)实现对炉膛温度的建模预测。首先,对实际运行生产数据进行小波降噪,并结合机理分析和分类回归树（classification and regression tree,CART）算法选取预测模型输入参数。然后,通过多种数据驱动方法构建锅炉炉膛温度预测模型。最后,采用决策树C4.5算法建立多模型智能组合预测模型。基于实际生产数据的实验结果表明,所提出算法能够建立准确的炉膛温度预测模型。     

二氧化碳和富氧空气对甲烷与乙烯燃烧的影响

利用碳氢燃烧实验台,研究了二氧化碳和富氧空气对甲烷、乙烯层流燃烧火焰的特性影响,分析了不同气氛下火焰结构特性和温度分布规律. 结果表明,随氧浓度从21%增加到50%(j),甲烷、乙烯火焰高度下降70%,火焰温度和亮度同时增加,且发光区域呈向下收缩趋势;相同氧浓度下,乙烯火焰亮度高于甲烷. 随CO2浓度由0增加到20%(j),火焰高度增加28%,各高度处火焰边缘温度平均下降290℃,中心温度平均下降132℃. 火焰亮度降低,由黄色变为暗黄色,底部亮度更低,CO2浓度超过20%(j)后,火焰出现悬浮状态,最终被吹熄.     

非线性偏最小二乘及可视化火焰检测系统的燃煤锅炉NOx排放特性的研究

为了研究燃煤电站锅炉NOx排放特性,利用可视化火焰检测系统对燃煤锅炉燃烧火焰和温度场进行了测试研究。通过测量,由双色测温法计算得到了炉内温度场,采用数字图像处理技术提取了火焰图像特征参数,进而借助非线性偏最小二乘法建立了由炉内燃烧温度场及火焰图像特征参数来预测NOx排放量的模型。结果表明,所建模型预测值与实测值具有一致性,从而为燃煤锅炉通过燃烧调整,以降低NOx排放和提高锅炉效率提供了有效手段。     

非线性偏最小二乘法及可视化火焰检测系统的燃煤锅炉NOx排放特性的研究

为了研究燃煤电站锅炉NOx排放特性,利用可视化火焰检测系统对燃煤锅炉燃烧火焰和温度场进行了测试研究。通过测量,由双色测温法计算得到了炉内温度场,采用数字图像处理技术提取了火焰图像特征参数,进而借助非线性偏最小二乘法建立了由炉内燃烧温度场及火焰图像特征参数来预测NOx排放量的模型。结果表明,所建模型预测值与实测值具有一致性,从而为燃煤锅炉通过燃烧调整,以降低NOx排放和提高锅炉效率提供了有效手段。     

大型乙烯裂解炉用低NOx燃烧器的结构优选

随着大能力大型化裂解炉的不断发展,国内首台单炉膛20万吨/年产能乙烯裂解炉对燃烧器提出了更高的设计要求,在稳定燃烧的同时还要满足特定的工艺要求和严苛的环保要求。采用CFD技术和热态试验方法优选新型乙烯裂解炉用低NO_x燃烧器,通过数值分析方法研究不同底部与侧壁供热比(底侧比)下裂解炉内的燃烧状态(火焰形状、火焰长度、炉内温度分布及NO_x排放量等),结果表明：在底侧比为70:30时燃烧状态最优,炉膛内温度分布均匀且满足工艺要求和环保要求。在热态试验炉上对最终设计工况(底侧比72:28)进行热态试验,结果显示:炉内燃烧状态良好,温度分布均匀且满足热通量曲线,NO_x排放量也较低。     

fsss系统在高压锅炉中的应用

监测炉膛火焰的燃烧状况是确保工艺操作人员安全和锅炉正常运行的前提条件。针对老式锅炉火焰监测系统的诸多问题和安全隐患实施技术改造,将炉膛安全保护系统应用在高压锅炉中,消除了安全隐患,改善了锅炉的运行状况,提高了生产经济效益。     

基于光学分层层析成像原理的火焰测温法

燃烧火焰温度场的测量无论对研究火焰的结构及生成机理、燃料的混合和燃烧方式,还是对燃烧设备的稳定运行和控制都具有重要的意义。介绍了一种利用高速分层摄像控制系统重建火焰温度场的方法。连续的三维发光体可以看成若干个互相平行的二维发光断层的组合,对发光体某断层进行聚焦摄像,得到的图像是该断层的像和其他断层的离焦像的叠加像。对不同断层分别快速聚焦摄像,得到一组辐射图像,采用图像反演算法,可以重建各断层的原始图像。根据图像灰度和火焰温度之间的关系,可建立火焰的三维温度场。通过蜡烛火焰实验,验证了该方法的可行性。实验结果在一定程度上揭示了火焰内部的辐射分布、温度分布和燃烧结构,反映了火焰的三维燃烧特性。该方法可作为一种新的测量和诊断方法,应用于燃烧火焰三维场参数和其他两相流三维场参数的测量中。     

融合电容层析成像先验信息的集合卡尔曼滤波统计估计

提出融合先验信息的电容层析成像(ECT)系统信息融合成像法——基于Bayesian重建算法的集合卡尔曼滤波融合算法(EnKF)。其优势在于能充分利用流体动力方面的先验信息,进一步修正原始迭代算法的重建图像质量。Bayesian重建算法在重建图像的迭代过程充分考虑噪声和图像的概率分布,完成初步成像过程。集合卡尔曼滤波算法利用先验信息实现对多相流流体流动的预测,继而改善成像质量。此外,为了便于估算误差的协方差,多相流的相分布作为EnKF融合方法的估计对象,用状态向量空间的灰度差分统计描述,明显改善了通过状态向量空间模型获得的统计估算结果。仿真和试验的结果都充分表明了在ECT系统中集合卡尔曼滤波融合方法的可行性。     

基于改进BP神经网络陶瓷梭式窑火焰图像识别方法

在陶瓷产品生产过程中,不同烧制阶段陶瓷梭式窑烧结带温度发生相应的变化,其对应的火焰图像也随着变化。本文针对陶瓷梭式窑烧结带温度检测提出一种基于改进BP神经网络的火焰图像识别方法。首先对获取的火焰图像利用改进的小波阈值算法去除图像中的噪音进行预处理,其次基于改进的BP神经网络对得到的火焰图像三个分量值R、G、B和测得的火焰温度进行数据拟合,最后测试已训练的神经网络识别火焰图像的效果。实验结果表明,改进后的BP神经网络收敛速度更快、训练时间更短、误差更小,能够更好地检测陶瓷梭式窑火焰图像温度。     

降低玻璃熔窑燃料消耗量的若干途径（连载七）

1.烟气进入蓄热室格子体的温度要适当提高.这常与池炉实行玻璃高温强制熔融的工艺相结合.在较高的空气(煤气)预热温度下,使燃料在炉膛内进行比较完全的燃烧,从而使池炉保持相当高的火焰空间温度,使火焰在炉膛内充分释放其热量,在尽量多地传递给玻璃料液之后,以比较高的温度离开炉膛,通过小炉进入蓄热室.为了少     

Monitoring and characterisation of pulverised coal flames using digital imaging techniques

Quantification of physical properties of fossil fuel fired flames is becoming increasingly important to achieve in-depth understanding and subsequent optimisation of combustion processes. This paper presents investigations into the geometrical and luminous properties of pulverised coal flames using an advanced flame monitoring system. The system combines optical sensing, digital image processing and computing techniques and is designed to measure most physical parameters of a flame. Experimental trials of the system have recently been conducted on a 1 MW_th coal-fired combustion test facility. The flame in the furnace was visualised continuously using the imaging system and then characterised in terms of geometrical and luminous parameters. Results obtained over a range of combustion conditions demonstrate that the system is capable of characterising the flames both qualitatively and quantitatively. The correlations between the flame parameters measured and the corresponding furnace data, including furnace load, mass flow rate of primary air and particle size, are identified and analysed.     

The research on the estimation for the NOx emissive concentration of the pulverized coal boiler by the flame image processing technique

In this paper, flame image processing technique is used to estimate NO_x emissive concentration of the pulverized coal boiler. According to the brightness value of flame image pixels, the temperature distribution of the flame is calculated. The combustion characteristic parameters are picked up from the flame image. Based on the back propagation neural network, the model to estimate the NO_x concentration in the gas released from the power plant boiler has been developed. The experiments on the furnace flame monitor system of a power plant have testified that this estimation model can get the satisfying results.     

新型含磷阻燃剂(PPOHQ)的合成及其在环氧树脂中的应用

以磷酰二氯和对苯醌为初始原料,合成一种新型的含磷阻燃剂双(2-对二苯酚基)-苯基氧磷(PPOHQ),并通过红外光谱对该化合物的结构进行了表征。利用该阻燃剂对环氧树脂进行固化,并对固化物进行了极限氧指数(LOI)、垂直燃烧(UL-94)、SEM以及锥形量热仪(CONE)等测试。结果表明,阻燃剂用量达到40%时,阻燃级别能通过UL-94V-0级,LOI的值为30.5。CONE测试结果表明,使用该阻燃剂固化的环氧树脂PHRR和THR等参数与EPO/PDA体系相比都有明显的降低。通过对残炭的SEM和FT-IR分析可知,燃烧后,固化的环氧树脂会产生磷酸类物质,促进形成致密的炭层,从而提高了阻燃性能。     

SA／CaSt改陛氯氧化镁／MCA阻燃抗熔滴PA6的性能研究

以硫酸镁与氨水为原料,采用硬脂酸／硬脂酸钙作为复合改性剂,合成改性氢氧化镁阻燃剂。将制备的改性氢氧化镁与三聚氰胺氰尿酸盐（MCA）添加到尼龙（PA6）中,通过挤出造粒制备复合阻燃（PA6）。分别研究不同阻燃剂配比对复合材料力学性能、耐热性能、阻燃性能及机理的影响。结果表明：随着MCA／改性氢氧化镁比例的增大,复合阻燃PA6的拉伸性能与冲击性能均先上升后下降,当两者比例为1：1时,力学性能达到最优。同时,两阻燃剂协同作用,使尼龙6阻燃机理由解聚分解转化为直接炭化分解,有效抑制燃烧流滴现象,提高了复合材料的综合阻燃性能。     

Gas combustion in a narrow channel at high pressure

This paper presents experimental results on the effect of pressure on the flame propagation velocity in a tube with diameter close to the critical diameter. An important feature of the investigated combustion regime is heat transfer along the tube wall from the combustion products to the fresh mixture. Methane-air and hydrogen-air mixtures were used. The experiments show that with increasing pressure, the burning velocity of methane-air flames decreases whereas the burning velocity of hydrogen-air flames is almost unchanged. This behavior is explained by the pressure dependence of the laminar burning velocity.     

Impact of co-firing coal and biomass on flame characteristics and stability

This paper presents the use of vision-based measurement techniques for the on-line monitoring and characterisation of coal-biomass co-firing flames on an industrial-scale combustion test facility. The characteristic parameters of the flame, including ignition points, brightness, temperature and oscillation frequency, are measured using a vision-based flame monitoring system in an on-line continuous mode. A common type of pulverised coal was fired with five different types of biomass for different proportions ranging from 0% to 20% by weight. Various combustion conditions were created during the test runs, including variations in excess air and the method of biomass injection. The relationships between the flame characteristics and the primary combustion process data are analysed. The results suggest that, due to the varying physical and chemical properties of the biomass fuels, the biomass additions impact on the characteristics of the flame, particularly the flame ignition points and brightness. However, in all cases studied, the flame stability has been found to be little affected by the amount of biomass added provided that the addition is no more than 20%.     

Combustion of residual steel gases: laminar flame analysis and turbulent flamelet modeling

In recovery combustion systems operating in the steel industry, energy is provided by boilers burning residual gases of blast furnace and coke oven. To help understand combustion of this particular type of fuels, a numerical study is conducted where the major chemical properties of steel gas flames are collected. The chemical composition of representative fuel and oxidizer steel gas is varied over a large range in calculations using detailed chemistry and complex transport properties. The chemical equilibrium compositions, premixed flame speeds and diffusion flame extinction strain rates are determined. The advantages and shortcomings of the use of vitiated air emerge, and its introduction into the boiler appears as an interesting alternative to reduce NO_x emission. The detailed information obtained with laminar flame calculations is also introduced in flamelet turbulent combustion modeling. Reynolds Averaged Navier Stokes (RANS) simulations of a test case burner are performed and some comparisons between numerical predictions and experimental results are presented.     

耐水阻燃透明型环氧树脂的制备及其应用研究

以二苯基次磷酰氯和哌嗪为原料,成功合成了疏水性阻燃剂哌嗪-1,4-二烷基双(二苯基氧化膦)(PPDO),并将其添加到环氧树脂(EP)中,制备了阻燃EP复合材料.通过垂直燃烧、氧指数、热失重分析、锥形量热分析和力学性能测试对EP复合材料的阻燃性能、热分解行为、燃烧行为和力学性能进行了详细研究.结果表明,阻燃剂含量为17％...     

新型膨胀型阻燃剂阻燃聚丙烯的研究

以五氧化二磷、磷酸、季戊四醇和三聚氰胺为原料,合成了一种新型的膨胀型阻燃剂（IFR）并和聚磷酸铵（APP）聚四氟乙烯（PTFE）复配对聚丙烯（PP）进行阻燃,用热重法（TG）对阻燃PP的热性能进行了研究,利用氧指数仪测定了阻燃PP的极限氧指数（LO I）值,用垂直燃烧法测试了其燃烧等级,当阻燃剂含量为24%时,LO I值为30.9%。用锥形量热仪对阻燃PP的燃烧性能进行了分析,并用扫描电镜（SEM）对阻燃聚丙烯（FR-PP）的残炭结构进行了研究,结果表明,该复配阻燃剂能够促进PP的成炭性,具有优良的阻燃PP性能。     

延迟焦化装置炉管结焦原因分析及预防措施

加热炉炉管结焦是影响延迟焦化装置长周期运行的主要因素,对加热炉炉管结焦的原因进行了分析,包括原料性质、炉管壁温度、原料在炉管中的流动状态、焦粉携带、加热炉火嘴燃烧状况以及原料预混情况对炉管结焦的影响,通过采取改善原料性质、控制合适的炉管壁温度、改善原料在炉管内的流动状态、防止焦粉携带、保证火嘴燃烧正常等措施,达到了加热炉长周期安全运行的目的。