福建无烟煤粒度分布对循环流化床锅炉燃烧影响的工业实验

作者在一台20t/h循环流化床锅炉上进行了燃烧三种不同粒度分布的福建Ⅱ类无烟煤的工业实验，取得颗粒平均粒径与悬浮段颗粒浓度、飞灰含炭量以及悬浮段颗粒与炉膛温度等关系曲线。有关数据与结论对燃烧福建无烟煤的CFB锅炉的设计运行具有参考价值。 同时，作者对提高CFB锅炉热效率及降低飞灰含碳量提出了几点建议。     

提高我省循环流化床锅炉热效率探讨

出力足、热效率高、安全稳定运行时间长及排放污染物少是对循环流化床锅炉（以下简称CFBB）的基本要求。经过多年的努力,我省CFBB在提高锅炉出力上已经积累了不少经验,并取得成效。如何尽快提高锅炉热效率已是当前迫切需要解决的问题之一。从我省已投入运行的CFBB来看,其热效率一般仅达65一72％。这不仅造成严重的资源浪费和经济损失,同时也影响CFBB在我省的进一步发展。根据我国的CFBB技术水平和本省一些热效率较高的CFBB的经验,在近期将我省CFBB的运行热效率（有别于设计或鉴定测试热效率）提高到接近SO％或更多一些不仅…     

无烟煤飞灰循环增压流化床燃烧试验研究

在ＳＥＵ－ＰＦＰＣ装置上进行了阳泉无烟煤燃烧试验,研究了流化速度、床层深度和床层温度对燃烧效率的影响。试验结果表明,采用飞灰循环回燃后燃烧效率可达９９．８％     

循环流化床锅炉热效率影响因素的试验研究

对一台75t/h循环流化床锅炉进行了详细的热效率试验,在试验结果的基础上,研究分析各影响因素对循环流化床锅炉效率及其各项热损失的影响,所得结果对如何通过改进循环流化床锅炉的设计和运行来提高锅炉热效率提供有意义的指导。     

循环流化床锅炉燃烧粗颗粒无烟煤的工业试验

作者在一台蒸发量２０吨／时的低倍率循环流化床锅炉上进行了燃烧三种不同粒度分布的福建Ⅱ类无烟煤的工业实验,得到给煤颗粒平均粒径与悬浮段颗粒浓度、飞灰含碳量、炉膛各段温度、以及悬浮段颗粒浓度与温度等关系曲线,热态实验表明：低倍率循环流化床锅炉更适合燃烧粗颗粒的福建省无烟煤,它不仅解决因飞灰量过大造成的环境污染问题,而且还提高了锅炉的热效率。     

浅析我省循环流化床锅炉的几个问题

本文从我省近几年投运的循环流化床锅炉中常见的几个问题分析入手,着重对影响该炉型的出力、热效率等问题进行剖析,并提出相应的建议。     

循环流化床锅炉燃烧飞灰的改造

机械抛煤炉在热电企业中应用广泛，具有煤种适应性广、燃烧调节快等优点，但也明显存有飞灰损失大，飞灰量多，可燃物含量高，飞灰污染环境等问题，不但影响环境，而且给企业造成了经济损失。为此，就绍兴市热电厂飞灰再燃烧的技改经验加以介绍。     

CFB锅炉热效率及空气预热器漏风性能试验研究

依据循环流化床锅炉性能试验规程,以唐山开滦东方发电有限责任公司2台490t/h CFB锅炉为例,进行热效率和空气预热器漏风性能试验。计算表明,在工况Ⅲ条件下,1#和2#炉热效率分别达88.37%、85.74%,比设计工况热效率分别降低了2.83个百分点和5.46个百分点;1#和2#炉空气预热器漏风系数分别为0.156、0.153,比设计工况漏风系数高4个百分点和2个百分点。研究表明,锅炉的性能试验结果可为其运行优化提供数据支持。     

循环流化床锅炉的发展方向

介绍了循环流化床锅炉的历史由来及其发展,并针对其特点较详尽地阐述了循环流化床锅炉与其他炉型相比较所显示出来的优点,最后指出为实现循环流化床锅炉的进一步优化需解决的几个问题。     

降低燃用福建无烟煤循环流化床锅炉飞灰含碳量浅谈

煤质特性、燃料颗粒、总体设计和运行工况是影响福建无烟煤在循环流化床锅炉中燃尽的主要因素。结合2台燃用福建无烟煤的DG75/3.82-11型CFB锅炉的运行情况,采取一系列有利于福建无烟煤在CFB锅炉中燃尽的措施:改善燃料粒径配比,采用窄筛分偏粗颗粒入炉煤;炉床温度控制在960~1 020℃,整个炉膛维持均衡的高温;改造回料风系统,减少或避免返料偏流,改善燃烧状况;改造二次风机和二次风喷嘴,提高二次风速,增强二次风的扰动穿透能力;优化运行调节,控制风煤配比,维持煤器后烟气含氧量在4%左右,一次风率在55%~60%、上下层二次风比为55:45~60:40,维持恰当的料层高度,一次风室压力控制在10~11kPa,达到较佳的燃尽效果。运行实践证明,这些措施可有效地降低飞灰含碳量。     

Heat transfer in a large-scale circulating fluidized bed boiler

Heat transfer of a furnace in a large-scale circulating fluidized bed (CFB) boiler was studied based on the analysis of available heat transfer coefficient data from typical industrial CFB boilers and measured data from a 12 MW_e, a 50 MW_e and a 135 MW_e CFB boiler. The heat transfer of heat exchanger surfaces in a furnace, in a steam/water cooled cyclone, in an external heat exchanger and in the backpass was also reviewed. Empirical correlation of heat transfer coefficient was suggested after calculating the two key parameters, solids suspension density and furnace temperature. The correlation approach agrees well with the data from the large-scale CFB boilers. __________ Translated from Journal of Power Engineering, 2006, 26(3): 305–310 (in Chinese) [译自: 动力工程]     

燃用石油焦和煤添加脱硫剂循环流化床锅炉热效率计算

论述了循环流化床锅炉燃用石油焦和煤添加石灰石时对锅炉热效率计算的影响．通过分析循环流化床锅炉燃用石油焦和煤混合燃料添加脱硫剂时的物料平衡和灰平衡。得出采用国标GB10184-88《电站锅炉性能试验规程》计算锅炉热效率时，要对热量、烟气量和灰量进行修正。结合一台220t／h CFB锅炉实例，计算出实际测试工况下的热效率为89．5％。     

循环流化床锅炉设计方法探讨

阐述了目前国内外循环流化床锅炉的最新发展趋势 ,重点分析了循环流化床锅炉燃烧室和飞灰循环系统的设计 ,综合考虑了商用循环流化床锅炉的运行数据和前人的一些设计方法 ,在此基础上提出了作者认为合理的一套设计方案     

Heat flux distribution on circulating fluidized bed boiler water wall

The future of circulating fluidized bed (CFB) combustion technology is in raising the steam parameters to supercritical levels. Understanding the heat flux distribution on the water wall is one of the most important issues in the design and operation of supercritical pressure CFB boilers. In the present paper, the finite element analysis (FEA) method is adopted to predict the heat transfer coefficient as well as the heat flux of the membrane wall and the results are validated by direct measurement of the temperature around the tube. Studies on the horizontal heat flux distribution were conducted in three CFB boilers with different furnace size, tube dimension and water temperature. The results are useful in supercritical pressure CFB boiler design. __________ Translated from Journal of Power Engineering, 2007, 27(3): 336–340 [译自: 动力工程]     

Co-combustion of refuse derived fuel with Korean anthracite in a commercial circulating fluidized bed boiler

The effect of co-combustion of Refuse Derived Fuel (RDF) with Korean anthracite on the combustion and environmental performance was observed in the Tonghae commercial Circulating Fluidized Bed (CFB) boiler. High contents of oxygen and CaO in RDF reduced the amount of air required for combustion and the limestone flow rate for SO₂ capture in the CFB boiler, respectively. The temperature in the furnace exit increased slightly due to re-combustion of volatiles which resulted in limiting the co-combustion ratio of RDF for the CFB boiler to operate stably. With the increasing co-combustion ratio of RDF, the output voltages of electrostatic precipitator (EP), which consists of 2-channels and 5-stages collecting plates, decreased linearly. Eventually, stability of the EP could not be maintained above 5% of the RDF co-combustion ratio. The emissions of NO_x, HCl and dioxin during co-combustion did not change appreciably as compared to the case when Korean anthracite was burnt alone, which were also low enough to meet Korean emissions limits. On the other hand, chlorine contents in ashes emitted from the CFB boiler increased gradually with the increasing co-combustion ratio, which implied that most of chlorines were fixed by limestone.     

Transformation characteristics of Na and K in high alkali residual carbon during circulating fluidized bed combustion

In this study, the transformation characteristics of sodium (Na) and potassium (K) during combustion of Zhundong coal gasification fly ash in circulating fluidized bed (CFB) reactors were investigated by examining gasification fly ash (TCf) from a 0.1-MW CFB test system. Experimental results indicated that TCf was rich in Na and K, with water-soluble and insoluble Na the main Na forms. Insoluble K was the major K form in TCf, accounting for 70.6% of total K. Reactor bed temperature exerted important effects on Na release during combustion such that, as bed temperature increased, the proportions of Na in bottom and circulating ash decreased while the Na in fly ash increased. Hydrochloric acid-soluble and insoluble Na in ash accounted for a large fraction of total Na. However, insoluble K was the principle K form in ash and bed temperature showed little influence on K release and distribution in ash during combustion. With decreased flue gas temperature, the Na content in deposition ash initially increased, then decreased, and eventually stabilized, while the K content in deposition ash was basically unchanged. Agglomeration of ash particles occurred during combustion, being more apparent at higher gas temperatures, and the agglomerates were rich in Na, K, sulfur (S), chlorine (Cl), and calcium (Ca). Deposition ash Na was mainly contained NaCl and Ca/Na sulfates. The enrichment of these salts as well as of Ca sulfate in ash was the main cause of ash agglomeration and deposition.     

循环流化床锅炉燃烧系统动态特性分析

根据循环流化床锅炉(CFBB)的工作特点以及燃烧系统输入和输出过程变量间的耦合关系,讨论了CFBB的蒸汽压力和床温的动态特性。认为引起蒸汽压力变动的主要原因在于燃料量(内扰)和汽轮机调门的变化(外扰);而影响床温变化的主要因素是给煤量、风量、物料循环量的变动,并从传热和燃烧过程分析了这些因素间的相互耦合关系。这对CFBB燃烧自动控制系统的设计与调试,以及整个控制系统的可靠运行都至关重要。