循环流化床锅炉中灰循环倍率与燃烧产物热平衡方程式

循环流化床锅炉在炉膛、分离器和回料器组成的灰循环系统中 ,存在大量的循环灰量。它是载热体 ,从炉膛吸入或放出热量。虽然循环灰温降不大 ,然而循环灰量却极大 ,严重影响燃烧产物的热平衡。在循环流化床锅炉热力计算时 ,必须加以考虑     

循环流化床锅炉平衡计算与循环倍率的确定

正确地确定循环流化床锅炉的灰平衡计算方法和循环倍率，是循环流化床锅炉性能设计的基础。本文阐述了循环倍率和灰平衡计算的重要性，并从灰平衡计算方法分析出发，给出了各节点的灰量计算公式和循环倍率计算公式，找到了完善这一计算方法的关键参数。     

返料换热型循环流化床工业锅炉燃烧传热特性

试验研究了一台将全部蒸发埋管布置在回料阀中的11,t/h返料换热型循环流化床工业锅炉的燃烧传热特性.结果表明,锅炉分离器及回料阀中均存在显著的燃烧份额,并随锅炉负荷的变化而变化;回料阀埋管内工质蒸发量随锅炉负荷增加而显著增加,但其蒸发份额基本保持稳定;基于回料阀内循环灰碳平衡,对锅炉满负荷条件下的循环灰量进行了估算,并对循环灰特性及锅炉低负荷性能进行了探讨.     

CFB锅炉的分离器形式与分离效率的比较

分离器的形式决定了循环流化床锅炉的整体布置,它的性能直接影响锅炉的性能。在相似的燃料及其成灰特性、流化条件下,分离器的分离效果可以通过飞灰和循环灰的粒径分布体现出来。对各种分离循环床锅炉飞灰和循环灰粒径的比较结果表明,人口带有加速段的冷方型分离器的分离性能与相同当量直径的圆形旋风筒相同。     

75t/h循环流化床锅炉的结构改进及优化设计

通过对75 t/h循环流化床锅炉运行过程中出力不足和锅炉本体及钢结构晃动问题的分析研究,重新进行了设计、计算,并对锅炉蒸发受热面进行调整,对锅炉的灰循环方式进行改进。改进后锅炉的运行完全满足了设计要求,运行状况良好。     

不同燃烧方式生物质灰土壤循环特性对比

为研究燃烧方式对生物质灰土壤循环特性的影响,分别在锅炉、管式炉(700℃,800℃)、阴燃容器中燃烧制备了玉米秸成型燃料灰(渣),在农村炉灶中燃烧制备了玉米秸灰。实验检测了上述各灰的残碳率、p H值、水溶性、酸溶性、灰中各元素含量及灰中可溶钾含量。结果表明:1炉灶灰和阴燃灰总K含量9%,水溶K含量7%;锅炉渣水溶K几乎为零;2炉灶灰和阴燃灰水溶性分别约为17%和13%,高于其它灰;除锅炉渣外,各灰酸溶性均比水溶性高10%以上;3各灰均呈碱性,且p H值差别较小;4炉灶灰残碳率约为24%(固体不完全燃烧损失约7%),其余灰残碳率5%。因此,从生物质灰土壤循环特性来说,传统炉灶燃烧和阴燃优于高温锅炉燃烧,锅炉燃烧技术在提高生物质灰土壤循环特性方面仍有待改进。     

循环流化床锅炉几个运行参数调整与控制

1 循环倍率和飞灰份额对循环流化床锅炉运行的影响 锅炉选型时，用户应根据燃用煤种，确定循环倍率。循环倍率R的定义为：单位时间内的循环灰量与给煤量之比。它是循环流化床锅炉设计时的重要参数之一．它的大小与燃烧效率、适用煤种、受热面吸热量分配及锅炉的整体布置有关。实验数字表明：循环倍率大小与煤的低位发热量成正比，也就是说燃用低位发热值高的优质煤时，为了防止炉膛温度过高结渣．需要增加进入燃烧室的灰量．     

关于引进循环流化床锅炉运行中的主要问题及改进措施

介绍了我国引进循环流化床锅炉运行中产生的主要问题及改进措施。另外，作者对引进循环流化床锅炉共同存在的床渣冷却器的选型和漏灰问题提出了看法，供锅炉用户参考。     

循环流化床锅炉不加脱硫剂运行规律的探讨

保证循环流化床锅炉循环物料的成灰特性是循环流化床锅炉安全经济运行的重要条件,针对循环流化床锅炉运行中不加石灰石对锅炉运行的不利影响进行探讨,并提出了解决措施。     

循环流化床锅炉脉冲吹灰器改造与应用

为解决DG260-9.81/540-1型循环流化床锅炉尾部受热面积灰严重,造成排烟温度升高,锅炉热效率降低。公司将原有的声波吹灰器改造成脉冲吹灰器,改造后,锅炉尾部受热面积灰情况明显改观,锅炉排烟温度低于设计值,对同类型循环流化床锅炉吹灰器的选用有一定的借鉴作用。     

生物质与烟煤灰的理化特性及混合灰熔融特性研究

文章利用扫描电子显微镜(SEM)、X射线荧光光谱仪(XRF)、X射线荧光衍射仪(XRD)、灰熔融特性分析仪对4种生物质(海草、梨木、榛子壳、稻秆)灰与神木烟煤灰的混合灰的熔融特性进行了研究。研究发现:水生生物质(海草)灰的掺混使混合灰的熔融特性温度先升高再降低;两种木本生物质(梨木和榛子壳)灰的掺混使混合灰的熔融特性温度逐渐升高;草本生物质(稻秆)灰的掺混对混合灰熔融特性温度的影响与水生生物质灰类似。由XRF分析可知:Na2O和CaO对于混合灰的熔融特性温度有更明显的影响,随着混合灰中Na2O含量的逐渐增加,混合灰的熔融特性温度逐渐下降;随着混合灰中CaO含量的逐渐增加,混合灰的熔融特性温度逐渐上升。由XRD结果可知:水生生物质灰在高温下容易形成熔点较低的碱金属硅酸盐,使混合灰的熔点降低;木本生物质灰中的CaCO3含量较高,能够提高混合灰的熔点;草本生物质灰与水生生物质灰类似,含有的低熔点碱金属硅铝酸盐使混合灰的熔点降低。     

Phosphorus recovery from the biomass ash: A review

Biomass ash, generated during the thermal chemical conversion of biomass for energy production, is an industrial by-product which is often recognized as a solid waste, but there are some useful elements in the biomass ash such as phosphorus, etc. So through some technology and methods, the biomass ash can be transferred into a useful resource. The paper mainly includes the following aspects: biomass ash composition characteristics, biomass thermal chemical conversion for phosphorus and phosphorus recovery technology from biomass ash. Through these aspects literature review, not only the whole biomass ash characteristics was made clear, but also we think that the idea of phosphorus from biomass ash is feasible, especially for some high phosphorus ash such as sludge ash, meat and bone meal (MBM) ash, etc. So the review about phosphorus from the biomass ash is very important practical significance for biomass energy, biomass ash disposal and phosphorus resource.     

灰分对柴油机颗粒捕集器性能影响研究综述

分别从柴油机颗粒捕集器(DPF)灰分的成分、来源及性质,灰分对DPF压降、过滤效率和再生过程的影响,及DPF清灰方法等方面进行了综述。已有研究结果表明:润滑油添加剂是DPF灰分的主要来源;润滑油配方、灰分沉积形态及DPF载体结构不同时,灰分对DPF压降的影响效果会有所不同;灰分在DPF中的沉积一般会提高DPF的过滤效率,但会恶化催化型DPF(CDPF)的被动再生效果,影响DPF主动再生频率和DPF主动再生时的温度;重型柴油车DPF需要定期清灰,压缩空气反吹法是目前使用最广泛的DPF清灰方法。     

循环流化床锅炉灰渣综合利用

循环流化床锅炉属于低温燃烧,并且燃烧过程加入了大量的脱硫剂,导致其产生的灰渣较普通粉煤灰有很大差异.灰渣的物理、化学性质发生了很大的变化,钙含量明显增加,同时灰渣的数量明显增多.这些差异致使其难以用常规方式进行利用.因此研究和开发循环流化床锅炉灰渣的利用途径具有重要意义.综述了循环流化床锅炉灰渣在建材、农业、分选等方面的应用.     

不同煤种下循环流化床灰渣特性的试验研究

在一台 0 .5MW的循环流化床燃烧炉上对 4种不同煤种分别进行燃烧试验 ,对燃烧产生的灰渣的分析结果表明了煤种特性如挥发分、灰分和含碳量等对循环流化床燃烧过程的灰渣形成及其排放特性有很大影响 ,并获得了煤中挥发分、灰分及含碳量对底渣粒径及其含碳量、飞灰粒径及其含碳量、飞灰份额及燃烧效率等影响特性 ,对循环流化床锅炉的设计和运行有一定的指导意义。     

垃圾焚烧灰渣的成分分析及其熔融特性

在垃圾焚烧余热锅炉中,垃圾灰熔融特性是决定灰沉积危害程度的最重要特性之一。本研究通过测定垃圾灰的成分、灰熔点,系统分析垃圾灰熔融特性与其成分的关系,以及垃圾灰与低熔点煤灰在熔融特性与成分之间的区别,并以此对垃圾燃烧提出一些建议。     

An assessment of the physical,mineral, and rheological properties of fly ash for stowing in coal mines

With increasing environmental awareness, utilization of fly ash has become an attractive alternate to disposal. The objective of the present study was to investigate the physical, chemical, mineral, and rheological characteristics of fly ash for their potential utilization in stowing operation. The study was conducted with fly ash collected from the ash disposal system of Guru Govind Singh thermal power plant, Ropar, Punjab, India. From the characterization of the fly ash sample, it was found that the ash sample is enriched predominantly in silica; alumina and iron oxides fall under the category of F-type fly ash. The major mineral crystalline phase identified in the ash sample is quartz and mullite. Because of the properties of fly ash, it can be used as a stowing material in coal mines. The data obtained for critical velocity will help design a slurry pipeline system for the hydraulic stowing of fly ash slurry at any concentration and pipe size.     

Simulation of ash–water interaction and its influence on ash characteristics

With ever-increasing demand for electricity, the production of ash, produced from the coal-fired thermal power plants, and its hazardous impact on the environment, is continuously increasing. This poses a very challenging task of safe handling, proper disposal and utilization of the ash. Several ash utilization schemes, developed and reported by earlier researchers, are being practiced frequently these days. However, these studies do not take into account the quality of ash produced and the changes it may undergo, before it can be used for different applications.A common method of disposing ash is its wet disposal, where the ash is mixed with water to make slurry and is disposed off in the ash ponds or lagoons. Such a disposal system causes ash, and the alkalis present in it, to interact with water over a period of time and may lead to the formation of ash zeolites. As such, it would be interesting to study the effect of this interaction (i.e. formation of zeolites also termed as zeolitization of the ash) on physical, chemical and mineralogical characteristics of the ash. As geotechnical properties of a material depend on these characteristics, the influence of zeolitization on these properties of the ash must also be investigated. Such investigations are essential for the bulk utilization of the lagoon ash, in particular as a fill material, where properties like compaction, consolidation, hydraulic conductivity and its shear strength are very important.In order to simulate such ash–water interaction, controlled laboratory experiments have been conducted on a typical Indian lagoon ash. The present study deals with the details of the effect of zeolitization on physical, chemical, mineralogical and geotechnical characteristics of this ash. Studies were also conducted to explore the possibility of utilization of the lagoon ash, and the zeolitized ash, for various environmental applications viz. retention and removal of heavy metals from the industrial sludge.     

添加剂对煤灰熔融特性的影响

在8种煤灰中添加不同矿物质作助熔剂,对煤灰熔融特性进行研究;并用灰色系统方法对8种煤灰的矿物质成分和综合成分与煤灰熔融特性的相关度进行研究,然后对实验方法与灰色系统关联度方法进行比较研究.结果表明:添加剂可以降低煤灰熔融温度,也可以升高煤灰熔融温度,添加剂CaCO3为30%时,F煤和D煤得到最低熔点分别为1 250℃和1 350℃;添加剂硼砂(Na2B4O7·10H2O)为15%时,F煤到最低灰熔点1 150℃,硼砂为20%时,D煤可到熔点1 300℃以下.根据关联度方法可得到:酸性矿物质是影响煤灰熔融温度的主要因素,钠系物质对灰熔融性的关联度比钙系物质影响大,数学方法计算结果与实验结果相吻合.     

Assessment of tracing element characteristics of F-type fly and bottom ash mixture

Presently, fly ash–water slurry is transported to ash disposal site at very low solid concentration of approximately 15–20% (by weight), resulting in huge water and energy wastage which leads to several environmental and health problem. The production of a large amount of the toxic metal elements in the ash disposal system of the thermal power plants can pose negative environmental effects on human health and on plants. In the present study, an attempt has been made to investigate the leaching characteristics of fly ash at higher concentrations. The bottom ash was taken as an additive in the proportion of 10, 20, and 30% (by weight) to enhance the leaching characteristics of fly ash. The solid concentration of fly ash suspension was taken in the range of 40 to 60% (by weight). The addition of additive helps to reduce the tracing metal concentration of fly ash. Leaching experiment data show that leachate concentration of all tracing elements present in fly ash reduced maximum with 20% addition of bottom ash (by weight). The present study helps to improve the ash disposal system of the thermal power plant and to minimize the environmental impact.