Study of flame combustion of off-design binary coal blends in steam boilers

Changes in the structure of the fuel consumption by the thermal power stations of Ukraine caused by failure in supplying anthracite from the Donets Basin are analyzed and the major tasks of maintaining the functioning of the coal industry are formulated. The possibility of using, in the near future, the flame combustion of off-design solid fuels in the power boilers of the thermal power plants and combined heat and power plants is studied. The article presents results of expert tests of the TPP-210A and TP-15 boilers under flame combustion of mixtures of anthracites, lean coal, and the coal from the RSA in various combinations. When combusting, such mixtures have higher values of the combustibles yield and the ash fusibility temperature. The existence of the synergetic effect in the flame combustion of binary coal blends with different degrees of metamorphism is discussed. A number of top-priority measures have been worked out that allow for switching over the boilers designed to be fired with anthracite to using blends of coals of different ranks. Zoned thermal analysis of the TP-15 boiler furnace was performed for numerical investigation of the temperature distribution between the furnace chamber zones and exploration of the possibility of the liquid slag disposal and the temperature conditions for realization of this process. A positive result was achieved by combusting anthracite culm (AC), the coal from the RSA, and their mixtures with lean coal within the entire range of the working loads of the boilers in question. The problems of normalization of the liquid slag flow were also successfully solved without closing the slag notch. The results obtained by balance experiments suggest that the characteristics of the flame combustion of a binary blend, i.e., the temperature conditions in the furnace, the support flame values, and the degree of the fuel burnout, are similar to the characteristics of the flame of the coal with a higher reactive capacity, which proves the existence of the synergetic effect in the processes of cocombustion of coals of various grades.     

Modification of technological control units for superheated steam temperature at 210-MW power units of the Primor’ye Power Plant

The results of analysis of operation of the temperature control system for superheated steam at the BKZ-670-140F boilers of the Primor’ye Power Plant (GRES) are presented. The possibility of updating of the injection system to improve the reliability and economic efficiency of power units of electric power plants is considered.     

燃用混煤的循环流化床燃烧试验研究

不同燃料在循环流化床(CFB)锅炉上表现出不同的燃烧特性，其对锅炉的设计和辅机选型乃至锅炉系统设计都有不同的要求。通过对神火电厂燃用混煤的CFB燃烧试验，分析了该煤在CFB内的燃烧特点及运行中应该注意的问题，为电厂CFB锅炉正确运行提供了依据。     

Thermal gain of CHP steam generator plants and heat supply systems

Heating calculation of the surface condensate heat recovery unit (HRU) installed behind the BKZ-420-140 NGM boiler resulting in determination of HRU heat output according to fire gas value parameters at the heat recovery unit inlet and its outlet, heated water quantity, combustion efficiency per boiler as a result of installation of HRU, and steam condensate discharge from combustion products at its cooling below condensing point and HRU heat exchange area has been performed. Inspection results of Samara CHP BKZ-420-140 NGM power boilers and field tests of the surface condensate heat recovery unit (HRU) made on the bimetal calorifier base КСк-4-11 (KSk-4-11) installed behind station no. 2 Ulyanovsk CHP-3 DE-10-14 GM boiler were the basis of calculation. Integration of the surface condensation heat recovery unit behind a steam boiler rendered it possible to increase combustion efficiency and simultaneously decrease nitrogen oxide content in exit gases. Influence of the blowing air moisture content, the excess-air coefficient in exit gases, and exit gases temperature at the HRU outlet on steam condensate amount discharge from combustion products at its cooling below condensing point has been analyzed. The steam condensate from HRU gases is offered as heat system make-up water after degasification. The cost-effectiveness analysis of HRU installation behind the Samara CHP BKZ-420-140 NGM steam boiler with consideration of heat energy and chemically purified water economy has been performed. Calculation data for boilers with different heat output has been generalized.     

Development of measures to improve technologies of energy recovery from gaseous wastes of oil shale processing

Prospects of the use of oil shale are associated with its thermal processing for the production of liquid fuel, shale oil. Gaseous by-products, such as low-calorie generator gas with a calorific value up to 4.3MJ/m³ or semicoke gas with a calorific value up to 56.57 MJ/m³, are generated depending on the oil shale processing method. The main methods of energy recovery from these gases are either their cofiring with oil shale in power boilers or firing only under gaseous conditions in reconstructed or specially designed for this fuel boilers. The possible use of gaseous products of oil shale processing in gas-turbine or gas-piston units is also considered. Experiments on the cofiring of oil shale gas and its gaseous processing products have been carried out on boilers BKZ-75-39FSl in Kohtla-Järve and on the boiler TP-101 of the Estonian power plant. The test results have shown that, in the case of cofiring, the concentration of sulfur oxides in exhaust gases does not exceed the level of existing values in the case of oil shale firing. The low-temperature corrosion rate does not change as compared to the firing of only oil shale, and, therefore, operation conditions of boiler back-end surfaces do not worsen. When implementing measures to reduce the generation of NO_x, especially of flue gas recirculation, it has been possible to reduce the emissions of nitrogen oxides in the whole boiler. The operation experience of the reconstructed boilers BKZ-75-39FSl after their transfer to the firing of only gaseous products of oil shale processing is summarized. Concentrations of nitrogen and sulfur oxides in the combustion products of semicoke and generator gases are measured. Technical solutions that made it possible to minimize the damage to air heater pipes associated with the low-temperature sulfur corrosion are proposed and implemented. The technological measures for burners of new boilers that made it possible to burn gaseous products of oil shale processing with low emissions of nitrogen oxides are developed.     

基于超超临界锅炉O2/CO燃烧控制技术研究

为了确定最佳的燃烧工况,通过采集某电厂1 036 MW机组锅炉1个月运行数据分析,发现高负荷时烟气排放CO偏大,额定负荷时最大影响锅炉效率0.6%,导致供电煤耗增大,严重影响锅炉运行的安全性及效率。针对燃用设计煤及燃用混煤的锅炉,燃烧状态变化易造成燃烧不稳定及参数波动大、锅炉效率降低等问题,通过分析燃烧特性曲线,试图从反平衡计算出发,基于燃烧控制技术和自适应优化控制技术,通过寻优,实现各阶段负荷下锅炉效率最高、煤耗最低的燃烧工况。     

Retrofitting the operating coal-fired TP-87 and BKZ-320 boilers for vortex fuel combustion technology

Scientific and technical problems concerned with retrofitting the TP-87 boiler installed at the Novokemerovo cogeneration station and operating on Grade 2SS Kuznetsk coal and the BKZ-320 boiler installed at the Novosibirsk TETs-3 cogeneration station and operating on Berezovo coal from the Kansk-Achinsk coal field for vortex combustion technology are addressed. A conclusion is drawn that low-cost retrofitting of obsolete boilers at thermal power stations with retaining the existing boiler unit infrastructure is presently the most reasonable strategy of their further use.     

俄国大型(500 MW)燃用高灰分煤电站锅炉的设计特点及运行特性

综述俄国当代大型（500MW）烧高灰分煤锅炉的开发应用和运行改进经验。分析了该型炉燃烧、制粉等关键设备的改进效果,探讨了配锤击磨、MPS中速磨制粉系统、炉膛和燃烧设备、燃烧系统经济性及降低NOx排放等技术。     

循环流化床锅炉的发展及应用

清洁煤燃烧发电是国内外新崛起的发电技术,循环流化床是应用清洁烧燃烧技术的成果,为此,介绍了循环流化订（ＣＦＢ）锅炉的优点、目前国内研制开发的情况及其在电厂 的实际运行情况。此外,还分析了循环汉化床锅炉电厂与带脱硫装置常规燃煤电厂在各方面的差异,指出广东省建设循环流化床锅炉电厂的必要性。     

循环流化床锅炉在中国的发展与问题

循环流化床锅炉具有较高的燃烧效率、良好的燃料适应性和优越的环保性能，符合我国煤炭资源及动力用煤特点以及燃煤锅炉环境污染矛盾突出的实际情况。文章介绍了循环流化床锅炉在国外的发展情况，回顾了其在我国的发展历程。分析了其在我国得以发展的原因，以及我国大型循环流化床锅炉的市场情况，同时指出了当前我国发展循环流化床锅炉中存在的问题。     

解决耒阳电厂670t/h燃用劣质无烟煤锅炉稳燃问题的对策

系统地介绍了HG - 670 / 1 4 0 - 1 0WM燃用劣质无烟煤锅炉燃烧不稳定的原因及解决办法 ,对燃用劣质煤锅炉稳燃问题从理论上及对现场运行有一定的指导作用 ,尤其是对解决燃用劣质煤锅炉机组低负荷调峰的稳燃问题有重要的参考价值     

Efficiency of using direct-flow burners and nozzles in implementation of dry-bottom ash removal at the TPP-210A boiler furnace

In reconstruction of operating pulverized coal-fired boilers, one of the main factors is the choice of a method for slag removal: dry bottom ash removal (DBAR) or slag-tap removal (STR). In this case, ecological and economic aspects should be taken into account, and also the early ignition of pulverized coal fuel, the reliability of operation of the furnace walls in the mode without slagging, and the stability of slag removal should be provided. In this work, issues of changeover of the pulverized coal-fired boilers of the TPP-210A type from the STR mode to the DBAR mode are considered. As of today, the main problems during the operation of these boilers are the high emissions of nitrogen oxides together with flue gases into the atmosphere and the appropriated payoffs, a small range of loads available, the necessity of stabilization of the pulverizedcoal flame sustainability by using the highly reactive fuel, large mechanical fuel underburning, etc. Results of studying aerodynamics of a furnace with DBAR obtained in the process of physical simulation are given; technical solutions and preliminary design (configuration of burners and nozzles in the boiler furnace, conceptual design of the pulverized coal burner, configuration of TPP-210A boiler with the low heat liberation of furnace cross-section and volumetric heat release) are set forth, which are associated with the optimization of aerodynamics of furnace volume, when the direct-flow burners and nozzles are used, and with organization of the efficient staged combustion of solid fuel. Two versions of possible modernization of a boiler unit are considered. Under conditions of the planned increase in the steam production capacity, the most promising measures are as follows: the DBAR implementation with reducing heat releases of the cross-section and volume of the furnace approximately by half, the installation of the direct-flow burners and nozzles with injection of recirculation gases into the active combustion zone by bleeding them from the turning chamber.     

燃煤电厂配煤掺烧试验研究

根据火电机组燃烧调整、燃煤结构优化和经济性运行的要求,对某电站600MW机组进行了一系列配煤掺烧试验.从试验结果看,在燃用非设计煤种时应注意其燃烧特性,通过有关运行参数的控制以保证锅炉和制粉系统的安全运行.     

锅炉掺烧强结渣蔚县煤的研究

针对锅炉改烧非设计煤种或掺烧强结渣煤种有可能对锅炉设备的安全经济运行产生不利影响,利用煤质分析数据和现场运行数据,按照动力配煤燃料特性计算模型,计算出了不同掺烧比例下煤的成分组成,分析预测了混煤的主要结渣指标,对锅炉进行了多种配煤方案以及不同负荷点的热力计算,对锅炉在不同燃料掺烧比例下的安全与经济状况进行了全面的分析评估。分析计算表明:蔚县煤掺混比例不宜超过50%,在70%~100%负荷范围内可以保证主汽温度与再热蒸汽温度及合理的减温水流量,不必进行锅炉设备的改造,但运行中需加强燃烧调整与监督。实际试烧结果与分析计算结果基本吻合,该研究方法可为大型煤粉锅炉掺烧强结渣煤的安全经济性预测提供有益的参考。     

加速发展大型循环流化床技术 推进电源结构优化升级

我国以煤炭为主的一次能源结构 ,决定了以燃煤电站为主的电源结构在较长的时间内将不会有大的改变 ,而电站锅炉燃烧排放的有害气体是大气的主要污染源之一。为了保护环境 ,实现电力产业可持续发展 ,世界发达国家开发利用洁净煤发电技术 ,特别是通过 2 0万kW级循环流化床锅炉的成功运行 ,推动了循环流化床技术向大型化发展。文章从技术路线和实施途径对我国引进 30万kW级大型循环流化床技术建设示范电站并开发 6 0万kW级超临界大型循环流化床锅炉技术 ,推进洁净煤发电技术的发展 ,推进电源结构优化升级 ,进行了分析研究。     

CFB锅炉掺烧生物质技术及气力输送系统方案

概述了生物质能利用现状及在燃煤电厂掺烧的应用前景.对CFB锅炉掺烧生物质的制备及输送方案作了初步探讨,结合实例提出了具体的气力输送系统方案和设备选型方案.     

Estimation of capability of changing the boilers TP-14A at Kumertau Termal Power Station to burning B3 grade coal from Verkhne-Sokursky deposit

Currently, TP-14A boilers should be changed into burning off-design fuel: grade B3 coal of Verkhne-Sokursky deposit. Its share (by heat) in the fuel balance should be not less than 80%. A test burning of Verkhne-Sokursky coal was carried out, which showed that, in its present form, the boilers and dust-systems are not suitable to operate with this fuel, because their characteristics significantly differs from the project one. It is impossible to maintain the overheating temperature at the required level during operation on only coal; it is difficult to maintain the temperature behind the mills at the level of 200°C. The joint burning the coal with natural gas allows to solve these problems at operation of one or two mills. However, substantial fuel underburning, essential thermal maldistributions on the steam flows, and emissions of NO_x above permissible values is observed. Based on the results of test burning and joint calculations of furnace, boiler, and dust-systems, ways to solve these problems were developed. For modeling the furnace process, the Fluent and Sigma Flame software were used. Adapted mathematical models of the boiler and dust-preparing systems were created using the Boiler Designer and Stoker software. It is necessary to reconstruct the boiler plants, which can perform in two stages. In the first stage, the existing burners are replaced by the burners with turning nozzles and two-stage burning is arranged, and the inertial separators and recirculation of the drying agent are installed on the mills. In the second stage, the change to concentric burning is carried out, the heating surface of radiation part of the steam superheater increases, and the preset included hammer part is installed at the mill. It is shown that a positive effect should be obtained already after the first stage of reconstruction. The second stage of reconstruction will require additional expenses, but its implementation will allow to a greater extent to eliminate the disadvantageous in the operation of the equipment.     

神华煤结渣特性判别研究

对22个电厂的燃烧神华煤或以神华煤为主混煤的锅炉运行情况进行调研,以及对西安热工研究院有限公司(TPRI)一维火焰炉结渣试验结果进行分析,提出了大容量煤粉锅炉燃用神华煤结渣特性判别的Sc法和Stba法,其中Sc法判别性良好,而Stba法有一定实用性。     

型煤掺烧对火电厂综合经济性影响的分析

以山东某电厂2台1 025 t/h锅炉为例,分析了掺烧巨野型煤对锅炉效率、机组厂用电率、供电煤耗、燃料及发电成本的影响。分析表明:在当前型煤与原煤采购价格相差较大的情况下,燃用较低热值的型煤所节约的成本能够弥补煤耗升高所增加的成本,经济效益显著。同时,根据燃用型煤中的技术特点提出了合理的掺配措施。     

燃煤锅炉的稳定燃烧与优化配煤

针对国内火电厂燃煤锅炉在安全经济稳定燃烧方面存在的明显不足,分析了影响锅炉安全经济稳定燃烧的主要原因,介绍了当前锅炉改造的某些重要方法和要点.根据目前电厂燃煤的现状,指出了配煤混烧的必要性,介绍了配煤方法和优化配煤的评价原则,同时介绍了优化配煤系统软件的功能.