余热电站循环流化床补燃锅炉结渣原因的分析

近些年在水泥厂事补燃的余热电站设计中普遍采用了循环流化床锅炉做为补燃锅炉。CPC循环流化床锅炉是其中应用较多的一种,针对这种锅炉在葛洲坝水泥厂余热电站的实际运行中出现的结渣现象,分析了其结渣的原因及解决办法。     

水泥厂余热电站循环流化床锅炉热压火、热启动的生产经验

0 引言 循环流化床锅炉是近些年自国外引进的锅炉机组。它是以煤矸石等劣质贫煤为主要燃料,具有能源消耗低、运行效率高、负荷调整能力强、环保性能好等优点,特别适用于带补燃的水泥窑余热电站。虽然该型锅炉机组配有临时停炉热压火的技术规范,但走访的国内几家具有该锅炉机组的电站因附机设备故障而被迫临时停炉时,均采用的是低温（200～     

循环流化床锅炉飞灰含碳量的测定方法探讨

对循环流化床锅炉飞灰的烧失量和含碳量进行了对比 ,烧失量与含碳量差别很大。传统上用烧失量代替含碳量对循环流化床锅炉飞灰并不适用。本文提出用煤的工业分析方法测定循环流化床锅炉飞灰的含碳量 ,并测出循环流化床锅炉飞灰含碳量随粒径分布的变化关系。     

CPC循环流化床补燃锅炉内衬的改进

M厂为2000t／d水泥窑系统配套的12MW低温余热电站的补燃锅炉，其燃料为煤矸石，CPC炉技术参数见表1。该系统因旋风分离器内衬崩塌．多次发生旋风分离器堵塞的现象。本文就该处内衬的设计、崩塌原因及改进措施谈一谈。     

循环流化床锅炉飞灰含碳量的研究

循环流化床锅炉具有高效、低污染、煤种适应性广等优点。但我国流化床锅炉普遍存在着飞灰含碳量高,锅炉燃烧效率达不到设计值的问题。概述了影响飞灰含碳量的主要因素:如煤种、燃煤的粒径及风量等,重点探讨了燃煤的粒径对飞灰含碳量的影响,提出了维持锅炉稳定,降低飞灰含碳量,提高燃烧效率的一些措施。     

余热电站循环流化床锅炉给煤系统的改造

我公司回转窑余热电站HG—CPC65（45）-3．82／450℃型补燃锅炉机组是哈尔滨锅炉厂采用美国CPC公司技术设计制造的细粒子低速循环流化床锅炉。该炉以燃用煤矸石为主要燃料。给煤系统由变频调速圆盘喂料机控制给煤量，并通过给煤皮带机和机械风力抛煤机向炉膛供煤。     

循环流化床补燃锅炉灰渣量计算探

1 前言循环流化床燃烧方式是介于链条炉层燃烧与煤粉炉悬浮燃烧之间的第三种燃烧方式。近些年来,循环流化床锅炉技术有了长足的进步,其应用范围越来越广;其独特的燃烧方式,对燃料的适应性强,可燃用石油焦、煤矸石等各种高硫、高灰分的燃料;它的负荷调整范围大,对波动频繁的工况适应能力强,负荷调整范围可达30％～110％。所以,在我国新设计的带补燃的水泥厂余热电站中普遍地采用了这种形式的锅炉,如葛洲坝、七里岗、仓前、牡丹江、双阳、广东亨达利(220t/h循环流化床锅炉)等厂。另外,这种形式的锅炉环保性能好,通过在其炉内添加石灰石,脱去随燃料带进的硫,减少了烟气SO2的排放量。     

循环流化床锅炉飞灰可燃物含量高的原因分析

针对河南省中原大化集团有限责任公司动力厂2台75t/hCFB锅炉存在飞灰可燃物含量偏高的问题进行燃烧调整试验,分析各种因素的影响,提出改进措施和建议。     

循环流化床锅炉飞灰可燃物含量高的原因分析

针对大化热电厂2台CFB锅炉存在飞灰可燃物含量偏高的问题，进行燃烧调整试验，分析各种因素的影响，并针对影响锅炉热效率的主要因素－－排烟热损人和固体未完全燃烧热损失提出改进措施和建议。     

余热电站补燃锅炉省煤器磨损原因及改进措施

０概况我公司水泥窑余热电站HG－CPC６５（４５）－３８２／４５０型补燃锅炉机组是哈尔滨锅炉厂采用美国CPC公司技术设计制造的细粒子、低速循环流化床锅炉。该锅炉以煤矸石为燃料。在炉膛尾部烟道竖井中布置的上、下２组沸腾式钢管省煤器，均采用直径Φ３２mm、壁厚４mm的２０G无缝钢管做为蛇形管束，布置方式为错列布置。２００１年５月该炉正式投入运行使用，供蒸汽给１２０００kW发电机组。２００２年３月１日，发现尾部烟道回灰漏斗中有水，停炉后检查发现下级省煤器南侧最下一排第１根蛇形管爆裂长约５mm、宽约１mm左右的裂口，…     

降低循环流化床锅炉飞灰可燃物的探讨与实践

针对2台燃用福建无烟煤的DG75/3.82-11型CFB锅炉所存在的飞灰可燃物含量较高的问题,通过分析福建无烟煤特有煤质特性、燃料颗粒特性、锅炉总体设计和运行调整工况是影响福建无烟煤在CFB锅炉中燃尽的主要因素。针对性采取优化筛分破碎系统、增强二次风的扰动穿透能力、提高旋风分离器的分离效率、改造回料风系统以减少返料偏流等措施;同时不断摸索CFB锅炉运行规律,完善和优化运行方式,应用锅炉燃烧优化控制系统实现CFB锅炉的自动优化控制运行。2台锅炉平均飞灰可燃物含量从2003年的22.17%降低到2009年第1季度的15.03%。     

循环流化床中烟气飞灰汞迁移规律

在小型热态循环流化床试验台上进行褐煤、烟煤、无烟煤燃烧试验,研究3种典型煤的烟气气态汞和飞灰颗粒汞迁移规律。试验结果表明：褐煤、烟煤、无烟煤在燃烧过程中,炉膛温度、空截面风速、给煤量以及煤颗粒大小变化时,汞元素在烟气和飞灰之间的迁移规律相似;降低炉膛密相区温度和增大炉膛空截面风速可促进烟气气态总汞Hg^T（g）迁移到飞灰颗粒汞Hg（p）中,同时也促进烟气气态零价汞Hg⁰（g）向烟气气态二价汞Hg²⁺（g）和Hg（p）转化;增加给煤量,烟气气态总汞Hg^T（g）和烟气气态零价汞Hg⁰（g）减少,飞灰颗粒汞Hg（p）含量增加,并且影响Hg⁰（g）的转化;选择合适的煤颗粒粒度可以促进Hg⁰（g）的转化以及Hg^T（g）向Hg（p）迁移。随燃烧工况的变化,3种煤Hg^T（g）、Hg（p）和Hg⁰（g）含量变化趋势相似,但含量相差较大,Hg⁰（g）占Hg^T（g）的比例y值也不同,其中无烟煤的y值高于烟煤和褐煤的y值。     

Olive cake combustion in a circulating fluidized bed

In this study, a circulating fluidized bed of 125 mm diameter and 1800 mm height was used to find the combustion characteristics of olive cake (OC) produced in Turkey. A lignite coal that is most widely used in Turkey was also burned in the same combustor. The combustion experiments were carried out with various excess air ratios. The excess air ratio, λ, has been changed between 1.1 and 2.16. Temperature distribution along the bed was measured with thermocouples. On-line concentrations of O₂, SO₂, CO₂, CO, NO_x and total hydrocarbons were measured in the flue gas. Combustion efficiencies of OC and lignite coal are calculated, and the optimum conditions for operating parameters are discussed. The combustion efficiency of OC changes between 82.25 and 98.66% depending on the excess air ratio. There is a sharp decrease observed in the combustion losses due to hydrocarbons and CO as the excess air ratio increases. The minimum emissions are observed at λ=1.35. Combustion losses due to unburned carbon in the bed material do not exceed 1.4 wt% for OC and 1.85 wt% for coal. The combustion efficiency for coal changes between 82.25 and 98.66% for various excess air ratios used in the study. The ash analysis for OC is carried out to find the suitability of OC ash to be used as fertilizer. The ash does not contain any hazardous metal.     

不同负荷下循环流化床锅炉粉煤灰的理化性质研究

为拓展循环流化床锅炉粉煤灰的利用途径,开发粉煤灰综合利用技术,研究了不同负荷下循环流化床(CFB)锅炉粉煤灰的粒径分布、化学组成、物相组成、Al_2O_3溶出特性和微观形貌等理化性质,考察了锅炉负荷对粉煤灰理化性质的影响。结果显示,CFB锅炉负荷对粉煤灰的粒径分布、化学组成和物相组成等性质影响较小,对粉煤灰中Al_2O_3溶出率影响较大,Al_2O_3溶出率与样品颗粒的微观形貌有关,颗粒表面孔隙和裂缝越多,Al_2O_3溶出率越高。CFB锅炉粉煤灰中的无定形相含量较高,在70%以上;CaO在粉煤灰中的主要存在形式有3种:硬石膏、生石灰和无定形CaO。Al_2O_3均是以无定形氧化物的形式存在,煤样中的Al_2O_3在燃烧过程中更容易以飞灰的形式排出;石英和硬石膏更容易以底渣的形式排出。     

Electron microscopy and phase analysis of fly ash from pressurized fluidized bed combustion

The characterization of the typical fly ashes from pressurized fluidized bed combustion system (PFBC) in Japan and Europe was carried out by electron microscopy and phase analysis using energy-dispersive X-ray spectroscopy (EDX). The purity of limestone as in-bed sulfur removal sorbent influences the desulfurization reaction. The high-purity limestone yielded both hydroxyl ellestadite and anhydrite in Japanese PFBC ashes, while dolomite-rich limestone yielded anhydrite in European PFBC ashes. When the high-purity limestone was used, hydroxyl ellestadite particles were observed as the independent particles or the rim around limestone particles. The Al₂O₃ content in the glassy phase was inversely proportional to the CaO content in the glassy phase, suggesting that the glassy phases were formed from metakaoline and calcite as end members. Since hydroxyl ellestadite, glassy phase and metakaoline are reactive under hydrothermal conditions, PFBC ashes are expected to be used as raw materials for autoclaved products.     

Coal combustion characteristics in a circulating fast fluidized bed

The effect of coal size (0.73–1.03 mm), excess air ratio (1.0–1.4), operating bed temperature (750–900‡C), coal feeding rate (1–3 kg/h), and coal recycle rate (20–40 kg/h) on combustion efficiency, temperature profiles along the bed height and flue gas composition have been determined in a bubbling and circulating fluidized bed combustor (7.8 cm-ID x 2.6 m-high). Combustion efficiency increases with increasing excess air ratio and operating bed temperature and it decreases with increasing particle size in the bubbling and circulating fluidzing beds. In general, temperature profiles and combustion efficiency are more uniform and higher in a circulating bed than those in bubbling bed. Combustion efficiency also increases with increasing recycle rate of unburned coal in the circulating bed. The ratio of CO/CO₂ of flue gas decreases with increasing bed temperature and excess air ratio, whereas the ratio of O₂(CO + CO₂) decreases with bed temperature in both bubbling and circulating fluidized beds.     

Modelling of circulating fluidized bed combustion of a char

The combustion of a char in the 41 mm ID riser of a laboratory circulating fluidized bed combustor has been investigated at different air excesses and rates of solids (char and sand) circulating in the loop. Riser performance was characterized by an axial oxygen concentration profile as well as by the overall carbon content and particle size distribution. The proposed model accounts for carbon surface reaction, intraparticle and external diffusion, and attrition. External diffusion effects were relevant in the riser dense region where char was potentially entrapped in large clusters of inert solids. Experimental data and results of the model calculations are in satisfactory agreement.     

Hydrothermal synthesis of zeolitic material from circulating fluidized bed combustion fly ash for the highly efficient removal of lead from aqueous solution

The utilization of coal fly ash derived from circulating fluidized bed combustion(CFBFA) still faces great challenges because of its unique characteristics. In this study, a zeolitic material with Na-P1 zeolite as the main phase was successfully synthesized via a hydrothermal method by using CFBFA as the raw material.The effects of hydrothermal temperature, time, and added CTAB amount on the characterizations of synthesized materials were investigated by XRD, SEM, and XPS. The properties of the ...