MPS-HP-II型磨煤机磨制兰炭的选型研究

近几年,在一些火电行业的循环硫化床机组中已将兰炭作为一种燃料,使用效果良好。在煤粉锅炉中,还需要合理的设备将兰炭磨制成合格的细粉,输送至锅炉中燃烧,充分发挥兰炭的优势。该文以兰炭为燃料,采用MPS-HP-II型磨煤机磨制兰炭,为兰炭在煤粉炉中成功应用提供有力保障。该文根据兰炭的相关资料,对磨煤机进行了选型计算、热平衡计算,做出了合理的选型方案。同时针对兰炭超强的磨损性选择了合理的高耐磨性材料,解决了耐磨件寿命问题。     

碗式中速磨煤机运行特性试验研究及应用

为提高制粉系统运行的安全性和经济性,对300 MW锅炉碗式中速磨煤机制粉系统进行了优化调整试验。试验研究了碗式中速磨煤机出力特性、磨煤机分离器挡板特性,调整了磨煤机最佳通风量,获得了磨煤机分离器折向挡板刻度与煤粉细度、磨煤电耗、磨碗差压的关系曲线。试验结果表明：随分离器折向挡板刻度的增大,煤粉细度变小,磨碗差压增大,磨煤机电流增加。根据磨煤机特性试验,提出了磨煤机最佳通风量、磨煤机出力及分离器挡板开度控制范围,并依据磨煤机运行情况提出设备缺陷检修建议,优化试验工况的磨煤机单耗下降8.5%,节能效果比较明显。     

总量控制实现掺烧篁石净化粉的准确计量

篁石净化粉是高效燃煤添加剂，其作用是使劣煤优用，优煤少用，且利于环境保护。１９９８年初，我热电厂在２２０ｔ／ｈ燃煤锅炉上进行了篁石净化粉掺烧试验，效果良好。篁石净化粉作为燃烧添加剂不论在掺烧试验还是工业应用中，按比例添加都十分重要，本文就试验过程中篁石净化粉掺烧比例的计量实践作一介绍。试验设备及工艺如图１所示。试验设备有：可输出４～２０ｍＡ瞬时煤流量信号的称重式全封闭给煤机；加净化粉料斗；可调速的皮带机；变频调速器；以单片机为核心的控制仪。其工作流程是：称重给煤机将煤送至磨煤机，磨好的煤粉送入煤…     

FMH型风扇磨煤机磨制污泥的选型研究

该文以某污泥耦合发电项目改造工程为基础,选用风扇磨直吹式污泥干燥、掺烧一体化技术,该技术特点是污泥直接送入风扇磨直吹式系统进行干燥、粉碎,干燥粉碎后的污泥以合格的粒度直接输送至电站锅炉内燃烧发电。提高污泥的热能利用效率,节约投资成本,能很好地解决城市污泥问题,对环境保护具有重要意义。该文中对污泥的成分进行分析后,确定制粉系统的选型原则,对风扇磨煤机的型号、热平衡进行了详细计算,确定选用FMH型风扇磨煤机磨制污泥,并详细介绍了风扇磨的运行原理。     

降低HP1003型磨煤机磨辊轴承损坏率

通过对HP1003型中速磨煤机运行情况的分析,针对磨煤机运行使用过程中存在的磨辊装置轴承箱易漏入煤粉的问题,经分析得出对磨煤机密封件进行改造可降低磨辊轴承故障率,对于磨煤机运行的安全起到了很好的保障作用,同时也对维护成本进行了控制,有效地降低了成本。     

1000MW燃煤机组制粉系统调整试验研究

制粉系统的优化调整对燃煤锅炉机组安全经济运行具有重要意义。为了提高制粉系统运行的安全性和经济性,对某电厂的一台1000MW超超临界机组锅炉的制粉系统进行了优化调整试验。在保证合理煤粉细度和煤粉均匀性的基础上,研究了通风量、加载油压、磨煤机出力及分离器转速等指标对制粉系统节能运行和锅炉燃烧特性的影响,提出的优化运行参数可以有效提高制粉系统出力和锅炉效率。试验结果有助于实现制粉系统的经济运行,调整经验值得推广和借鉴。     

DH-3型助燃固硫除灰剂技术研究

本文通过在煤粉炉、循环流化床锅炉及手烧锅炉上进行的助燃脱硫试验表明：掺加粉煤灰、电石渣、蒙脱土、白云石粉可以提高生石灰的脱硫效率及钙利用率,掺加冰晶石、钡盐等可促使煤粉着火和煤的燃尽率,这种作用与反应温度有密切关系,在反应温度700℃～900℃范围内脱硫效果较好。本文也研究了粉煤灰、电石渣与生石灰的掺混方法,对脱硫效率和钙利用率的影响。与此同时,通过向石灰石粉中加入冰晶石、钡盐和粉煤灰不同的剂量燃烧后,有不同的效果。该技术不但促使粉煤灰着火,而且提高燃尽率和脱硫效率。     

燃煤锅炉改造为掺烧高炉煤气和全烧高炉煤气分析

高炉煤气的利用方式很多,目前我国最主要的利用方式是高炉煤气发电项目(包括燃烧高炉煤气和高炉煤气、煤粉混烧)。分析燃煤锅炉掺烧高炉煤气和全烧高炉煤气后的工况变化,并提出改造措施,对钢铁行业的燃煤锅炉改造具有借鉴意见。     

某电厂褐煤和印尼煤掺烧经验介绍

介绍了某电厂锅炉混煤掺烧实用经验、运行技术和安全措施;总结了实施混煤掺烧过程中出现的问题;提出了部分解决问题的方法,并对混煤掺烧管理方面给出了具体建议,为燃煤电站实施混煤掺烧提供有益参考。     

油页岩与无烟煤掺烧特性研究

为了进一步拓展油页岩应用的领域,本文通过对无烟煤和油页岩的成分分析,依据理论计算,对无烟煤与油页岩按不同比例掺配时的稳燃特性、燃尽特性、沾污特性以及结渣特性进行了分析研究。总结出其变化规律,随着油页岩比例增加,稳燃特性指数和燃尽特性指数都处于上升趋势,而结渣特性随着油页岩掺入,当无烟煤与油页岩比例上升至为6:4时,由无烟煤的严重结渣特性下降到中等结渣特性。文中简单分析了引起变化的主要影响因素,为油页岩与无烟煤掺烧提供理论依据。     

Optimization of the process of plasma ignition of coal

Results are given of experimental and theoretical investigations of plasma ignition of coal as a result of its thermochemical preparation in application to the processes of firing up a boiler and stabilizing the flame combustion. The experimental test bed with a commercial-scale burner is used for determining the conditions of plasma ignition of low-reactivity high-ash anthracite depending on the concentration of coal in the air mixture and velocity of the latter. The calculations produce an equation (important from the standpoint of practical applications) for determining the energy expenditure for plasma ignition of coal depending on the basic process parameters. The tests reveal the difficulties arising in firing up a boiler with direct delivery of pulverized coal from the mill to furnace. A scheme is suggested, which enables one to reduce the energy expenditure for ignition of coal and improve the reliability of the process of firing up such a boiler. Results are given of calculation of plasma thermochemical preparation of coal under conditions of lower concentration of oxygen in the air mixture.     

Laser-induced breakdown spectroscopy for determination of the organic oxygen content in anthracite coal under atmospheric conditions

Laser-induced breakdown spectroscopy has been used to measure the organic oxygen content in pulverized anthracite coal under atmospheric conditions. Special spectral processing including the optimal O(I) emission-line selection by comparing the spectral correlation coefficients with the N(I) line, internal normalization with the N(I) line, and temperature correction are proposed and employed to satisfy the multi-line analysis method and yield the most accurate quantitative results. The calibration method for determining the organic oxygen content of coal is presented, with an accuracy of 1.15-1.37% and an average relative error of 19.39% being evaluated through an experiment performed on six anthracite coal samples. The relative measurement error distribution has also been studied.     

利用正交法进行燃烧优化的试验研究

利用正交法研究了氧量、风箱炉膛差压、煤粉细度及配风型式对锅炉效率、NOx排放量的影响。通过试验发现,影响锅炉毛效率的因素依次是氧量、风箱炉膛差压、配风方式、煤粉细度;影响锅炉净效率的因素依次是氧量、煤粉细度、配风方式、风箱炉膛差压;影响NOx排放量的因素依次是配风方式、氧量、煤粉细度、风箱炉膛差压。     

用DSC法研究混入煤粉的铵油炸药相容性

为了研究混入煤粉的铵油炸药的相容性以及煤粉与铵油炸药之间的相互作用,采用差示扫描量热仪(DSC)研究了铵油炸药、混入煤粉的铵油炸药、硝酸铵和混入煤粉的硝酸铵的热分解特性。用Kissinger方程求解了铵油炸药和混入煤粉的铵油炸药的表观活化能(E_a),考察了煤粉与铵油炸药的化学相容性。研究结果表明:在常压氮气氛围的环境中,铵油炸药和硝酸铵的DSC曲线中的热分解均为吸热峰;当煤粉和硝酸铵混合后,煤粉与硝酸铵会在硝酸铵的热分解温度之前发生化学反应,随着煤粉含量的提高,硝酸铵的热分解逐渐转变为放热峰,说明煤粉能极大地降低硝酸铵的热稳定性;使用DSC法研究混入煤粉的铵油炸药相容性等级为4级,煤粉与铵油炸药的相容性差。     

特定纳米结构燃烧催化剂在电厂煤粉炉中使用的效果

为考查具有特定纳米结构燃烧催化剂在电厂煤粉炉中使用的效果，在火电厂进行了一系列试验．结果验证了该助燃剂适用于煤粉炉，有增加煤的发热量以及节能降耗的效果，催化作用时效持续24小时以上；但仍有添加量偏大等问题，有待后续试验完善。     

制粉系统调整及改造对优化机组性能的影响

针对锅炉燃烧面临的问题,详细分析了煤粉细度、煤粉均匀性以及燃料空气分配特性等反映制粉系统性能的指标对锅炉燃烧特性以及运行经济性、安全性等性能的影响,提出了制粉系统的优化调整及改造思路,总结出制粉系统调整及改造对机组性能的影响.     

Field test corrosion experiences when co-firing straw and coal: 10 year status within Elsam

Abstract

In Denmark, straw is utilised for the generation of energy and district heating in power plants. Combustion of straw gives rise to high contents of potassium chloride and some sulphur dioxide in the flue gas. These compounds can lead to deposits with high content of potassium chloride and potassium sulphate on superheater tubes resulting in increased corrosion rates. From field experimental results this paper show, that by co-firing straw with coal, corrosion rates can be brought down to an acceptable level.

This paper firstly deals with the results from a demonstration program co-firing coal and straw at the 150MW pulverized coal fired boiler Studstrup unit 1. Two exposure series lasting 3000 hours each were performed for co-firing 10 and 20% of straw (% energy basis) with coal. Using built in test tubes in the hot end of the actual superheaters and air/water cooled corrosion probes, the corrosion during these experiments was monitored. Various ferritic and austenitic materials were investigated at steam temperatures ranging from 520 to 580°C and flue gas temperatures ranging from 925 to 1100°C.

The results obtained in the demonstration program led to the rebuilding of the 350MW pulverized coal fired boiler, Studstrup unit 4, into a co-firing boiler with straw in 2002. During the rebuilding, test tube sections of X20CrMoV12 1 and TP347H FG were built into the superheater and the reheater loops. The temperature ranges during these exposures was for the steam from 470 to 575°C and for the flue gas from 1025 to 1300°C. All these test tubes have been removed during the last three years at one year intervals for corrosion studies.

The corrosion studies performed on all investigated tubes included measurements of the corrosion attack, light optical microscopy and scanning electron microscopy of the corrosion products.     

煤净化燃烧及伴生物产品化

煤净化燃烧及伴生物产品化新工艺,是在电厂燃煤中加特制的掺烧剂共同粉磨产生亲合颗粒,喷入锅炉内进行亲合煅烧。保证供热发电的同时实现降低残炭、提高粉煤灰活性、固结脱硫、降低Nox、CO2,并将全部固态伴生物在具有速烧速冷的燃煤锅炉内直接生成优质水泥熟料;实现基本消除燃烧的全部污染（气体和固体污染）,且不产生二次污染,从而达到清洁生产的目的。     

Experimental investigation on the flowability properties of cohesive carbonaceous powders

The flowability properties of two carbonaceous powers (anthracite coal and petroleum coke), including angle of repose (AOR), Hausner ratio (HR) and powder compressibility (C), etc., were determined. The effects of particle size, external moisture content (MC) and power type on powder flowability properties were investigated. The results indicate that as the powder particle size increases, the AOR, HR and C decrease, respectively, and the powder flowability becomes better. As the powder external MC increases, the AOR, HR and C increase, respectively, and the powder flowability becomes worse. The anthracite coal has lower values of AOR, HR and C, and higher values of flow function (FF) than those values of petroleum coke. Therefore, anthracite coal has better flowability compared to petroleum coke. Meanwhile, there exists a good linear correlation between AOR and HR.