Improving the reliability of the furnace and gas conduits of a Babcock-Wilcox boiler during the firing of natural gas in bottom slot burners

The influence of a gas flame arrangement method on the reliability of furnace bottom and burners is considered. Possibilities for reducing temperature nonuniformity of the flame, improving the reliability of partitions in the boiler gas conduits, and reducing the concentration of nitrogen oxides in the combustion products are indicated and measures for implementing them are outlined.     

火电厂锅炉折焰角斜坡积灰原因及对策

对大唐华银金竹山电厂600MW机组"W"火焰锅炉折焰角斜坡及水平烟道积灰的原因进行了深入分析。指出受热面布置不合理导致的烟气流速较低、折焰角斜坡角度小、贴近斜坡区域存在回流区和吹灰器存在吹灰盲区是导致该锅炉斜坡严重积灰的主要原因。为此,开发并在锅炉上安装了斜坡、水平烟道吹灰装置。经长期运行后发现,该吹扫装置运行良好,可干净地清除折焰角斜坡的积灰,且对炉膛负压没有影响,使积灰问题得到了彻底解决。     

Taking into account the nonuniform and unstable thermal structure of a furnace fireball when using multifunctional burners

It is shown that the operation of multifunctional burners becomes more efficient if the gas-dynamic nonuniformity of a flame and the unstable nature of its thermal characteristics are preliminarily taken into account and algorithms for controlling the temperature fields in furnaces are used. A model is proposed for taking into account the nonuniformity of the fireball temperature in furnaces equipped with once-through multifunctional multinozzle burners.     

锅炉炉膛出口烟温偏差调整

HG1025-18.2-YM6型锅炉的炉膛出口至尾部烟道处存在较大烟温偏差,加上积灰、结焦等问题,导致受热面产生较大热偏差,蒸汽流量相对较小、工作压力较低的再热器爆管频繁.由于此方面的设备技改投入大,周期长,很难在短期实施,所以,为缓解这种状况,从运行角度进行调整,使这种状况得以改善.     

A mathematical model of slagging of the furnace of the pulverized-coal-firing boiler

The mathematical model of furnace slagging integrated into the Sigma-Flow program system of computational hydrodynamics has been developed; this system makes it possible to calculate aerodynamics, processes of heat-and-mass exchange, and combustion processes in complex technological facilities, including pulverized-coal-firing furnaces.     

Optimizing the flame aerodynamics and the design of tangentially arranged burners in a TGMP-314 boiler

Technical solutions for optimizing the flame aerodynamics and the design of tangentially arranged burners in a TGMP-314 boiler are proposed. The implementation of these solutions will make it possible to achieve more reliable operation of the boiler during fuel oil combustion, smaller amount of NO _x emissions during the combustion of gas and fuel oil, and a somewhat lower air excess factor in the furnace.     

Studying the Aerodynamics of the TPP-210A Boiler Furnace When It Is Shifted to Operate with Dry-Ash Removal and Vortex Fuel Combustion

To reduce the amount of nitrogen oxide emissions and achieve more reliable operation of the TPP-210A boiler, a process arrangement for firing Grade TR Kuznetsk coal that involves using straight-flow burners and shifting the boiler from slag-tap to dry-ash removal is developed. Owing to a large burner downward slope angle and special arrangement of burners and nozzles, four large vertical vortices rotating in opposite directions are produced in the furnace lower part, as a result of which the combustion products dwell for a longer period of time in the burning zone and more complete fuel combustion is achieved. For verifying the operability and efficiency of the proposed combustion arrangement, investigations on a boiler furnace physical model were carried out using a technique for visualizing fuel jets and secondary and tertiary overfire air jets. The fuel jet temperature boundaries in the course of jet propagation in the furnace model are also determined. The study results have shown that staged fuel combustion will be set up with using the proposed arrangement of burners and nozzles. In addition, large vertical vortices produced in the furnace lower part will help to achieve more efficient use of the dry bottom hopper heating surfaces, due to which lower coal combustion product temperature in the furnace upper part and smaller content of combustible products in fly ash will be obtained. Owing to low values of air excess factor at the pulverized coal burner outlet and gradual admission of air into the vortex zone through a few nozzles with intense inner recirculation of combustion products to the jet initial section, staged combustion of pulverized coal and low nitrogen oxide emissions will be secured. Owing to expansion of fuel jets, a rapid growth of mass in the fuel jet is achieved, which is obtained both due to ejection of the jet itself and due to forced admission of hot fuel gases from other jets. Investigations carried out on the physical model have confirmed that the proposed combustion arrangement features high efficiency and that a low content of nitrogen oxides in flue gases is obtained.     

炉膛烟气压力分布以及对锅炉运行的影响

煤粉锅炉一般采用“平衡通风”法 ,即锅炉配有送风机和吸风机。运行中送风机和吸风机均开启 ,保持炉膛顶棚受热面之下 (1— 2 )ｍ处负压值为(2 0— 30 )Ｐａ ,使整个炉膛处于负压状态 ,从而防止炉内烟气向外泄漏。在运行中炉膛内的烟气自下向上流动 ,而后流入烟道 ,从烟气的绝对压力而言 ,自然是下部压力高于上部压力 ,否则不可能产生自下向上的流动 ,下部压力与上部压力的差值即为炉膛内的烟气阻降 ,这一阴降是靠风机和烟囱的自拔风来克服的。炉膛下部压力比上部压力高 ,下部压力究竟是负压还是正压 ,这是我们要研究的问题。很多锅炉运行的…     

低NOx燃烧器对锅炉运行的影响及改进措施探讨

就扬州第二发电厂引进B&W锅炉存在的减温水量过大的问题对EI-XCL型低NOx燃烧器的设计运行加以分析,提出改进燃烧器需注意的经济安全问题,使电厂既高效运行又有效降低排放.     

锅炉折焰角水冷壁管空化沟槽造成爆管原因分析

报告了某超高压锅炉折焰角水冷壁管发生内壁过热腐蚀沟槽,造成水冷壁爆管的情况。沟槽及两旁有较薄的铁锈色氧化皮。通过对沟槽引起的爆管管段取样进行综合分析,排除了管材材质、传热过程等因素,最终认为是折焰角水冷壁管发生局部贴壁空化现象引起过热腐蚀。更换损坏的管段仍不是治本之策,建议从改变超高压锅炉折焰角形式设计等方面开展研究工作。     

Engineering solutions related to the furnace arrangement of a boiler designed for operating at supercritical steam conditions

When developing a coal-fired power unit designed for operating at supercritical steam conditions (SSCs), it is necessary not only to achieve high economic performance and the high reliability of a new power unit, but also to tackle many problems related to the efficient combustion of the solid fuel without exceeding the future standards for limitations on emissions of harmful substances into the atmosphere. The technological methods of suppression of nitrogen oxides capable of providing the permissible NO _x emissions are discussed. The results of calculations are given that demonstrate the feasibility of achieving the purpose in view by means of installation of new low-NO _x burners and staged injection of the fuel even on combustion of the Ekibastuz black coal high in ash content.     

锅炉炉膛冒正压力的原因分析及处理

针对煤粉锅炉炉膛冒正压的现象分析:炉膛上部,燃烧器口及整组燃烧器上部结焦脱落,和正常运行中吸风机调节品质不合理等是造成燃烧中炉膛冒正压的主要原因,提出了解决措施并进行了实施,消除了炉膛冒正压的现象。     

装设炉膛安全监控系统后防止锅炉爆燃需注意的问题

火电厂锅炉装设了炉膛安全监控系统后极少发生炉膛爆燃事故，针对可能存在的锅炉设备系统、管理和操作等方面容易忽视的问题，结合分析发生过的炉膛爆燃事例，提出在锅炉启动、运行、停炉及事故处理等方面需注意的一些问题，尤其是对油枪的管理使用问题，供火电厂技术管理及运行人员参考。     

降低600 MW机组锅炉炉膛出口烟温偏差的试验研究

在分析了美国B&W公司设计制造的600 MW机组锅炉EI-XCL型低NOX双调风燃烧器结构特点的基础上,针对扬州第二发电有限公司600 MW机组2号锅炉存在的两侧烟温偏差过大问题,通过进行锅炉冷态试验和燃烧调整试验,确定了锅炉燃烧优化运行方式,降低了锅炉两侧烟温偏差,提高了锅炉运行的经济性和安全性.     

循环流化床锅炉炉内飞灰浓度的计算

本文指出了循环流化床锅炉内飞灰浓度是影响流化床传热的重要因素,推导出了炉内飞灰浓度的计算公式。     

脱硫灰渣排放方式与综合利用

脱硫灰渣作为火电厂产生的一种新型的固体废弃物,其组成和性能与其排放方式有着密切的关系。为了使其得到较好的处置与利用,本文主要从排放方式加以探讨,叙述了各种脱硫灰渣的性能与综合利用前景。     

影响煤粉炉飞灰可燃物含量的因素分析

在燃煤电厂中,由于锅炉的不完全燃烧,使锅炉的飞灰可燃物含量增加,导致锅炉效率降低,发电成本增加。通过深入探讨锅炉飞灰可燃物含量的影响因素,提出了维持锅炉稳定燃烧、降低飞灰可燃物含量、提高锅炉效率的有效措施,为锅炉高效经济运行提供参考。     

Mathematical simulation of working processes in the furnace of a circulating fluidized bed boiler

A software system developed for simulating and calculating boiler furnaces with circulating fluidized beds is described. The main principles on which the system is constructed are outlined, and the physical and mathematical models of processes in circulating fluidized bed furnaces are described together with the calculation algorithm. Results from a study of analyzing the effect the grinding fineness of initial fuel particles has on the processes in a circulating fluidized bed furnace are presented.     

双炉膛汽包炉分层燃烧高低灰熔点煤试验分析

结合电厂调整来煤结构、降低标煤单价的实际需求,介绍国电谏壁发电厂改进型双炉膛控制循环汽包炉掺烧低熔点神华煤的实施方法。通过对神华低灰熔点煤掺烧高灰熔点煤的结渣特性和灰渣成分试验分析的研究,结合炉型的结渣特性判别及对混合燃烧高低灰熔点煤和分层燃烧高低灰熔点煤的实践比较,提出炉型偏矮的锅炉采取分层加仓掺烧低灰熔点煤的方案是更好的选择,通过控制一次风速,避免产生还原性气氛,既解决了掺烧低灰熔点煤导致锅炉严重结焦、排渣困难的问题,又节约了输煤电耗,社会效益和经济效益显著。