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国内水泥生产用煤煤质普遍偏低,提高分解炉对煤质的适应性成为当前预分解技术的一个十分迫切需要解决的问题,本文从理论与实践两方面对影响分解炉内煤粉燃烧的主要因素进行了必要的分析与讨论,认为强化煤粉夺富氧含量气体中燃烧,适当提高炉温是改善煤质适应性的主要措施,根据煤质与分解炉燃烧条件选取合理的炉容是保证炉内煤粉的燃烧时间的主要手段,2000t/d离线喷腾型预分解系统以三次风净空气作燃烧气体,在分解炉本体 相似文献
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不同类型燃煤工业锅炉具有各自的技术优势及应用范围,为了给用户在项目立项、选择锅炉时提供正确参考,阐述了3种主流燃煤工业锅炉的技术特点、应用现状,并着重针对循环流化床锅炉和现代煤粉工业锅炉,从燃烧组织方式和技术特点两方面进行了系统的技术对比分析。经分析认为,流态化燃烧组织是循环流化床锅炉的技术基础,浓相室燃燃烧组织是现代煤粉工业锅炉的技术基础。依托密相床炉料的巨大热容量,循环流化床锅炉定位于处理高灰劣质燃料;依托低变质高活性清洁煤粉快响应着火喷燃,现代煤粉工业锅炉定位于油(气)锅炉的备份及互换。因此,二者非取舍而是互为补充的关系。 相似文献
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燃煤电厂作为人为汞释放源之一,其对环境的影响日益受到人们的重视。煤粉锅炉和循环流化床锅炉是燃煤电厂应用较多的两种炉型。主要介绍了该两种炉型在燃煤过程中汞释放行为的研究进展。对于煤粉锅炉来说,大部分汞存在在烟气中,而只有少部分汞富集在飞灰,底渣和脱硫石膏中。而循环流化床锅炉的汞则主要富集在飞灰中,只有少部分汞富集在底渣中或烟气中。对任一炉型,锅炉的燃烧方式以及其配置的大气污染控制装置不同,可导致汞在燃烧产物中的再分配比例不同;同时,飞灰对汞有一定的吸附作用,且粒径越小、含碳量越高及停留时间越长越有利于飞灰对汞的吸附。 相似文献
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利用一套4 t/h燃煤热水示范锅炉对5种煤进行实验,分析煤质对锅炉大气污染物的影响,并计算不同煤种锅炉大气污染物的排污系数.结果表明,在相同条件下,不同煤种锅炉大气污染物产排放情况不尽相同,其中烟尘产生浓度在328.86 mg/m3~3 634 mg/m3之间,排放浓度在30.26 mg/m3~72.91 mg/m3之间,烟尘产生量在0.7 kg/h~11.7 kg/h之间,排放量为0.07 kg/h~0.31 kg/h;SO2的产生浓度在199mg/m3~3 565 mg/m3之间,产生量在0.83 kg/h~16.21 kg/h之间;排放浓度为69mg/m3~1 443mg/m3,排放量在0.34 kg/h~7.51 kg/h之间;NOx的产生浓度在173 mg/m3~336 mg/m3之间,产生量为0.75 kg/h~1.52 kg/h;排放浓度为159 mg/m3~371 mg/m3,排放量为0.67 kg/h~1.93 kg/h;SO3产生浓度在0.000 4 mg/m3~0.001 5mg/m3之间,排放浓度在0.000 15 mg/m3~0.000 93 mg/m3之间.实验发现烟尘浓度主要与煤质灰分有关,二氧化硫与燃煤含硫量有很大的关系,氮氧化物浓度与煤质中的氮含量关系不大.从排污系数来看,本实验锅炉烟尘排污系数小于全国污染源普查系数,二氧化硫和氮氧化物的排污系数与普查结果比较接近. 相似文献
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湿法脱硫装置对燃煤锅炉PM2.5排放特征的影响 总被引:1,自引:0,他引:1
采用二级稀释采样方法对1台电厂煤粉炉、1台电厂CFB锅炉和2台工业层燃炉配备的WFGD前后烟气中PM2.5进行现场采样。采用ELPI分析PM2.5的数量及质量浓度粒径分布;通过SEM分析PM2.5的显微结构,通过XRF、ICP-OES和离子色谱法分别对PM2.5中次量、痕量元素及水溶性离子含量进行测定。研究结果表明,相比于WFGD前,煤粉炉和CFB锅炉WFGD后PM2.5质量浓度减少,而层燃炉WFGD后PM2.5质量浓度增加。WFGD后PM2.5中存在大量块状、层状、片状、细小柱状和球形颗粒聚合体的结构,浆液成分及脱硫产物的附着会使PM2.5的外观形貌特征发生显著变化。脱硫后由于脱硫浆液的参与,PM2.5中Ca、S及相应Ca2+、SO42-含量显著增加,Si和Al的含量下降;气相的As、Se和Hg也会发生不同的化学变化从而进入PM2.5。湿法脱硫过程中浆液会捕集烟气中颗粒物,但脱硫浆液成分及脱硫产物会经由干化作用直接形成颗粒或与原有颗粒经碰撞聚合形成新颗粒。 相似文献
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《Filtration Industry Analyst》2003,2003(11):4
Mitsubishi Heavy Industries has been awarded a contract for the construction of a 1434 MW coal-fired power plant by BLCP Power Ltd of Thailand.Visit www.filtsep.com for the latest filtration industry news 相似文献
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电厂煤燃烧过程中汞的形态分布及迁移转化行为分析 总被引:3,自引:0,他引:3
阐述了煤炭燃烧过程中汞的形态分布和迁移转化行为。说明煤炭燃烧过程,汞主要以Hg^0形态存在。用化学热力学的理论对不同的煤样中汞的燃烧形态变化进行了计算分析,并描述了温度对其迁移转化的影响和作用。 相似文献
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This paper presents the experimental results on the fouling propensity of five pairs of blended coals (19 coals and blends) tested in the Australian Coal Industry Research Laboratory (ACIRL) furnace. The results showed that the coal D has the highest fouling propensity among tested coals and blends. A parameter, growth rate (mm/h), is used to numerically rank the fouling propensity based on photos of fouling deposits taken over a period of test time. The growth rate correlates the fouling propensity better than the build up rate or the fouling coefficient. Five empirical fouling indices are examined against the fouling propensities of the above 19 coals and blends, and another 10 coals and blends previously tested in the Energy and Environmental Research Cooperation (EER) furnace. The linear correlation between the flue gas exit temperature/initial deformation temperature (FGET/IDT(ox.)), a measure of the overall heat transfer in the furnace, and the Na2O, g/GJ, is proved to be a good tool for predicting the fouling propensity of coals. There is also a relationship between the FGET and the growth rate. 相似文献
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On-site measurements of volatile organic compounds (VOCs) in different streams of flue gas were carried out on a real coal-fired power plant using sampling bags and SUMMA canisters to collect gas samples,filters to collect particle samples,Gas chromatography-flame ionization detector/mass spectrometry and gas chromatography-mass spectrometry was the offline analysis method.We found that the total mass concentration of the tested 102 VOC species at the outlet of wet flue gas desulfuration device was (13456 ± 47) μg·m-3,which contained aliphatic hydrocarbons (57.9%),aromatic hydrocarbons(26.8%),halogen-containing species (14.5%),and a small amount of oxygen-containing and nitrogen-containing species.The most abundant species were 1-hexene,n-hexane and 2-methylpentane.The top ten species in terms of mass fraction (with a total mass fraction of 75.3%) were mainly hydrocarbons with a carbon number of 6 or higher and halogenated hydrocarbons with a lower carbon number.The mass concentration of VOC species in the particle phase was significantly lower than that in the gas phase.The change of VOC mass concentrations along the air pollution control devices indicates that con-ventional pollutant control equipment had a limited effect on VOC reduction.Ozone formation potential calculations showed that aromatic hydrocarbons contributed the highest ozone formation (46.4%) due to their relatively high mass concentrations and MIR (maximum increment reactivity) values. 相似文献
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燃煤烟气中的SO3会对机组运行及大气环境造成不利影响。为研究燃煤电厂SO3排放特征,本文采取异丙醇吸收法对某300MW超低排放机组污染物控制装置进出口SO3采样,以分析SO3在燃煤机组中的迁移及脱除特性。结果表明:炉膛燃烧过程以及选择性催化还原装置(selective catalytic reduction,SCR)均将部分SO2转化为SO3,炉膛燃烧生成SO3的质量浓度为SO2的0.86%,SCR内SO2/SO3转化率为0.45%。烟气经过空气预热器,SO3浓度降低了5.7%;静电除尘器(electrostatic precipitator,ESP)脱除SO3效果较差,主要由于ESP内烟温在110℃以上,H2SO4酸雾凝结量较少;双级湿法脱硫装置(wet flue gas desulfurization,WFGD)对SO3脱除效率达到81.3%,比国内单级脱硫装置SO3脱除效果高30%~50%;湿式静电除尘器(wet electrostatic precipitator,WESP)脱除SO3效率为23.0%。机组烟囱排放SO3质量浓度为2.025mg/m3(标准),SO3排放因子EF为0.034kg/t。 相似文献
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燃煤锅炉内结焦会对锅炉运行的安全性和经济性造成极大损害,因而分析影响燃煤锅炉结焦的因素,进而有效预防燃煤锅炉结焦至关重要。在实际应用中,针对影响燃煤锅炉结焦的不同因素,可采取不同的预防措施。研究发现煤的灰熔融性温度、煤粉颗粒大小、锅炉燃烧气氛、一二次风动力场、锅炉截面热负荷和锅炉热负荷等都会影响燃煤锅炉结焦。为了解决某地区煤粉工业锅炉预燃室、炉膛、对流受热面大面积燃烧结焦问题,笔者结合燃煤锅炉燃烧结焦的机理,先后采取调整燃烧气氛、增大二次风刚性、减小煤粉颗粒粒径、更换孙家岔煤粉等措施对不同条件下的结焦现象进行对比分析,发现煤种、煤粉粒径大小是影响某地区煤粉工业锅炉燃烧结焦的因素。通过SEM-EDS(扫描电镜和能谱分析)对锅炉焦块进行微观形貌与元素组成分析,现场取样锅炉现用煤粉和孙家岔煤粉进行煤质及灰成分对比分析,并根据灰成分进行结渣性判别指标计算,结果表明锅炉燃烧现用煤种灰熔融性温度较低,煤灰软化温度Ts为1 170℃,小于1 200℃,为易熔煤,容易结渣,属于典型的易结焦煤种;结渣性判别指标计算结果显示,4项指标评价为"严重",1项指标评价为"中等",结渣性严重。综合分析认为:锅炉燃烧煤种发生改变,煤的灰熔融温度较低是影响某地区煤粉工业锅炉燃烧结焦的最本质因素。为进一步解决现场实际问题,采取破坏煤灰中酸碱平衡,提升煤的灰熔融温度,配合调节煤粉粒径等措施,如对锅炉现用煤种掺混5%的石英,提高煤灰中Si O2含量,掺混后煤粉的灰熔融温度达到1 280℃,提高了110℃;调大煤粉磨机频率,从19 Hz增大到22 Hz,煤粉粒度(200目,0.075 mm)过筛率从70%增大到85%。经过上述调整后,锅炉运行平稳,结焦状况显著改善,燃烧调整措施取得了较好的效果。 相似文献
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Fouling deposits due to surface-coated particles have been calculated using computational fluid dynamics techniques. The sticking probabilities of the surface-coated particles are also evaluated on the basis of an energy balance. The sticking probabilities of the deposit surface are also included in the prediction of the deposition occurring through the multiple impaction of particles with the deposit surface. The sticking probability of an impacting particle is expressed in terms of such parameters as particle viscosity, surface tension, impact velocity, impact angle and the thickness of the sticky layer on a particle. Particulate behavior around a tube in cross-flow was studied using the Lagrangian approach. Three important parameters, i.e. impact velocity, impact angle, and particulate concentration, were used in the prediction of deposition rate. The computational predictions were found to be in good agreement with the experimental data. 相似文献