Mercury Emission From Coal-fired Power Plants in China

燃煤是最大的人为汞排放源之一，燃煤电厂的汞排放控制问题也越来越为人们所关注。该文将目前公布的中国电厂的汞排放数据进行筛选汇总，得到18个电厂的汞排放数据，通过对比和分析，总结出了符合我国燃煤电厂特点的一般性汞排放规律。结果表明：与美国煤种相比，我国的燃煤具有低氯、高灰的特性，这不利于汞的排放控制；循环流化床燃烧可能会因燃尽率的不同而较煤粉炉燃烧易获得较高的Hgp；空气污染控制设备的使用能够有效地减少汞排放，选择性催化还原＋静电除尘器／布袋除尘器＋石灰石-石膏湿法脱硫（SCR＋ESP／FF＋WFGD）组合的平均脱汞率可达71．48％；SCR的大规模应用可能会将汞大量转移到飞灰和脱硫石膏中，带来二次污染的问题。

Cause Analysis and Countermeasure of Gypsum Rain in Coal-fired Power Plants

Focusing on the phenomenon of gypsum rain while wet desulphurization(WFGD) were adopted in coal fired power plant without GGH, the paper studied and put forward the solutions : (1) desulfurization facilities related equipment modification;(2) optimal operation of existing desulfurization facilities.

Progress and prospects of innovative coal-fired power plants within the energy internet

The development of electrical engineering and electronic, communications, smart power grid, and ultra-high voltage transmission technologies have driven the energy system revolution to the next generation: the energy internet. Progressive penetration of intermittent renewable energy sources into the energy system has led to unprecedented challenges to the currently wide use of coal-fired power generation technologies. Here, the applications and prospects of advanced coal-fired power generation technologies are analyzed. These technologies can be summarized into three categories:(1) large-scale and higher parameters coal-fired power generation technologies, including 620/650/700 oC ultra-supercritical thermal power and double reheat ultra-supercritical coal-fired power generation technologies;(2) system innovation and specific, highefficiency thermal cycles, which consist of renewable energy-aided coal-fired power generation technologies, a supercritical CO_2 Brayton cycle for coal-fired power plants, large-scale air-cooling coal-fired power plant technologies, and innovative layouts for waste heat utilization and enhanced energy cascade utilization;(3) coal-fired power generation combined with poly-generation technologies, which are represented by integrated gasification combined cycle(IGCC) and integrated gasification fuel cell(IGFC) technologies. Concerning the existing coal-fired power units, which are responsible for peak shaving, possible strategies for enhancing flexibility and operational stability are discussed. Furthermore, future trends for coal-fired power plants coupled with cyber-physical system(CPS) technologies are introduced. The development of advanced, coal-fired power generation technologies demonstrates the progress of science and is suitable for the sustainable development of human society.

Optimization of an Existing Coal-fired Power Plant with CO²Capture

Nowadays, the worsening environmental issue caused by CO2 emission is greatly aggravated by human activity. Many CO2 reduction technologies are under fast development. Among these, monoethanolamine (MEA) based CO2 capture technology has been paid great attention. However, when connecting the CO2 capture process with a coal-fired power plant, the huge energy and efficiency penalty caused by CO2 capture has become a serious problem for its application. Thus, it is of great significance to reduce the related energy consumption. Based on an existing coal-fired power plant, this paper proposes a new way for the decarburized retrofitting of the coal-fired power plant, which helps to improve the overall efficiency of the power plant with less energy and efficiency penalty. The decarburized retrofitting scheme proposed will provide a new route for the CO2 capture process in China.

Atmospheric Dry Deposition in the Proximity of Oil-Fired Power Plants at Mexican Pacific Coast

Dry deposition samples were collected in a weekly basis during 2010 in a site located at the Mexican Pacific Coast: Manzanillo, Colima. Samples were collected with an automatic wet/dry deposition sampler using nylon filters as surrogate surfaces. Samples were extracted with deionized water and analyzed for pH, conductivity, Na+, K+, Ca2+, Mg2+, NH4-, NO3-, SO42- and Cl-. Nitrate and sulfate were the most abundant ions, contributing with 53% to the total ionic mass;and their levels exceeded the hemispheric background concentrations proposed for marine remote sites. The influence of the power plants burning combustoleo located upwind the sampling site was completely evident. From meteorological analysis, it could be observed that the sampling site was all time under the influence of power plants as a result of the effect of breezes. However, in spite of the high levels of NO3- and SO42- found in the samples collected, pH value average was almost neutral, with 28% of samples slightly acid. Potassium was the most abundant cation and from the quantification of the neutralization effect of the main alkaline components, the prevalence role of K+ was completely evident, suggesting the influence of the mining complex Pe?a Colorada located upwind the sampling site, where amyl xanthate potassium is used as collector in tailing dams. Dry deposition fluxes were estimated for all ions measured. Nitrogen dry deposition at Manzanillo is already in the upper extreme of the threshold value reported for sensible ecosystems. On the other hand, sulfur deposition exceeded slightly the critical load value reported for some ecosystems in Europe. Even at this moment, nitrogen and sulfur deposition is not a problem, it is necessary to take steps to avoid that total deposition of these elements exceeds critical loads, considering that results reported in this study not include the wet deposition fluxes.

Development of Carbon Dioxide Capture Technologies in Coal-Fired Power Plants

With a particular reference to China Huaneng Group's practices in CO_2 capture, this article presents a brief ing on the current development of CO_2 capture technologies in coal-fired power plants both in China and abroad. Sooner or later, the integration of CO_2 capture and storage (CCS) facility with coal-fired power plant will be inevitably put on the agenda of developers.

智慧电厂大数据云平台的架构建设与模型开发研究

火电机组运行智慧化是“双碳”目标约束下机组灵活运行的关键技术,基于大数据云计算平台的机组数字化架构是其重要组成部分。但目前现役机组的云平台改造建设尚缺乏深入技术探索及报道。以2台350 MW机组为例,系统开展了火电大数据云平台改造建设的实践研究。首先,发展了利旧的私有云平台搭建技术,实现了整合厂内原有6台服务器资源的低成本部署,同时保障建设期内机组正常运行;其次,针对火电机组万亿级的年数据量存储及电厂应用场景下数据读取需求,发展了云平台数据库数据同步技术,改进了数据库的测点管理方式及数据存储方式,开发了数据接口服务,使云平台数据库实现105量级测点数据的秒级写入及3 s内全年数据的单点检索。在此基础上,在云平台上部署了依托2.45×109条数据的大数据寻优算法,实现了机组能耗的可视化运行指导;搭建了针对高噪声测量数据的预处理模型,完成了对风量等数据的趋势提取;开发了选择性催化还原(SCR)入口NO x浓度的神经网络预测模型,并通过构建负荷变化因子对预测结果进行反馈调节,可捕捉不同幅度的喷氨量变化需求。上述模型框架均可在云平台实现灵活调整与拓展,所提技术可为火电企业及新型低碳/零碳燃烧能源设备的智慧云平台建设提供参考。

某燃煤电厂新型脱硫废水处理系统的调试与分析

以山东某燃煤电厂脱硫废水改造项目为背景,采用一体式高效澄清工艺替换原有三联箱工艺,处理SS高达13650 mg/L、CODCr为350 mg/L、重金属离子浓度超标的脱硫废水。处理前,先通过实验室小试确定基础加药量,缩小调试期间加药量范围;然后通过现场设备调试,优化运行参数,降低设备损坏率。经168 h的调试运行,新型脱硫废水处理系统运行稳定,污染物去除效果良好,出水SS在1.5 mg/L,CODCr在132.2 mg/L,总铅、总镉、总汞、总铬、总锌分别在0.14、0.01、0.01、1.04、1.24 mg/L,出水水质满足《火电厂石灰石-石膏湿法脱硫废水水质控制指标》(DL/T 997—2020)要求。与电厂原三联箱工艺相比,一体式高效澄清工艺不仅对水质有明显提升,而且年运行费用由100多万元降低至50多万元,经济效益显著。

循环流化床锅炉全负荷调峰特性研究

基于循环流化床(circulating fluidized bed,CFB)燃烧技术的燃煤发电机组可实现长周期压火热备运行与快速启停,即具备全负荷调峰能力。在某300 MW亚临界CFB锅炉上的试验结果显示,机组功率能够以10.4%Pe/min的速率快速降至1 MW,后在1%极低负荷率下维持长时间稳定运行,总压火时长超过110 min,压火结束后又能以3.5%Pe/min的速率实现热态再启。压火期间,平均床温以2.2℃/min的速度从800℃降至553℃;主汽温度和主汽压力分别下降了165℃和1.7 MPa;各受热面横向温度偏差基本在10℃以内;汽轮机和发电机运行平稳,各项参数都在安全限值以内。扬火瞬时烟气CO浓度急剧上升超过1%,但无爆燃风险。调峰全过程尘硫氮污染物排放小时均值满足超低排放要求。该研究为深入挖掘煤电机组灵活性提供了一个更具竞争力的方向,对高比例消纳风光等可再生能源、保障新型电力系统可靠稳定运行具有重要意义。

基于660 MW超临界燃煤发电机组深度调峰中的控制技术分析

在全球能源结构转型的大背景下,如何在保障电力系统稳定运行的前提下,提高燃煤发电机组的灵活性和调峰能力,成为电力行业亟待解决的重要课题。本文以660 MW超临界燃煤发电机组为研究对象,深入分析其在深度调峰过程中的控制技术,通过建立燃煤发电机组的变工况模型,分析了锅炉、汽轮机及辅助系统在不同负荷下的动态特性。本文提出了一种基于PID控制器的优化控制方法,并与现有方法进行了比较,实验结果表明,所提方法在深度调峰中的响应速度和精度优于文献[5]和文献[6]的方法,验证了其在深度调峰中的有效性和优越性。

燃煤电厂新型SCR反应器结构设计

燃煤电厂目前普遍采用选择性催化还原(SCR)法进行烟气脱硝,SCR反应器是烟气脱硝处理的主要设备,其设计方案直接影响烟气脱硝性能.SCR反应器在运行时承受多种荷载和作用,常规设计通常采用保守的框架形式,其材料利用率和受力性能存在局限性.为实现SCR反应器结构的高性能设计,对其受力特点和结构方案进行了研究,形成了结构空间布置和截面优化、提高结构刚度、温度应力和膨胀变形控制、内部压力控制、防积灰措施等关键技术解决方案,设计了一种新型SCR反应器结构.结果表明:该新型SCR反应器结构布置合理,催化剂层大梁的高度可以降低约50%,总用钢量可以节省约20%,同时有限元仿真分析表明结构具有良好的受力性能和安全性能.该新型SCR反应器在多个项目中得到了应用,使电厂氮氧化物(NO_(x))排放得到了有效控制,产生了显著的效益.

燃煤电厂脱硝工艺研究进展

燃煤过程中氮氧化物的排放严重影响大气环境质量。因此,减少氮氧化物对提高煤炭的有效利用具有重要意义。基于近几年的实验研究和机理研究,总结了燃煤电厂氮在燃烧过程中迁移和转化的影响因素和机制最新研究进展。首先,总结了选择性还原催化剂的最新研究进展,如脱硝装置、温度、气氛、加热速率、失活机制和催化剂在分子水平上对氮氧化物前驱体形成和氮迁移路径的影响;其次,总结了新技术模型对氮氧化物脱除的影响。为了从源头上减少氮氧化物的污染,有必要进一步改善热解过程中产生更多氮气的工艺条件和最佳配方,并阐明N2产生的路径。实验研究和量子化学计算应结合起来,完成燃烧过程中脱硝的研究。

大规模CCUS在新型燃煤发电机组中的应用

本文对燃煤电厂度电碳排放强度进行测算,提出新型燃煤发电机组二氧化碳捕集装置规模的建议,介绍醇胺吸收法在大规模二氧化碳捕集和封存利用(CCUS/CCS)中的应用及主要技术经济指标,针对实现燃煤电厂碳排放强度低于600 g CO_(2)/kWh要求的CCUS/CCS技术路线,详细分析了对原有系统的影响并提出了蒸汽和冷却水等系统优化方案,估算降低碳排放强度600 gCO_(2)/kWh条件下的CCUS/CCS运行费用及其对机组度电成本的影响。

燃煤电厂取水设施物理模型试验研究

某燃煤电厂调试阶段出现了循环冷却水量不足而导致机组停机现象,排查供水系统源头,发现取水泵运行时发生喘振,造成供水量不足,进一步引发机组停机。为保障燃煤电厂机组安全稳定运行,其取水水源需要稳定可靠,取水设施各部位尺寸应合理设计。以巴基斯坦某660 MW燃煤电站海水取水工程为例,对海水取水泵房及配套设施进行物理模型试验研究,并对设计方案进行了验证,试验结果表明,推荐设计方案布置可满足HIS(hydraulic institute standards)建议值,能保证取水设备安全稳定运行。

燃煤发电厂贮灰场建设光伏电站的应用探索

“双碳”目标下,以风电、光伏发电为主力的新能源发电迎来井喷式发展。而近年来,在中国粮食安全的战略抓手下,光伏发电用地政策或将进一步收紧,成为制约光伏电站投资的主要因素之一。若能将采用热电联产机组的燃煤发电厂的闲置贮灰场用于建设光伏电站,既能让贮灰场空地得到合理利用,又能解决光伏电站建设面临的场地问题,土地资源可得到充分利用。以在浙江省绍兴市某采用热电联产机组的燃煤发电厂贮灰场内建设的大型光伏电站为例,从光伏阵列设计、光伏电站收益及减排效果、贮灰场对光伏电站建设的影响这3个维度对此类光伏电站建设进行了可行性分析,结果显示:1)该光伏电站建成后每年可节约标准煤1271.51 t,减少的二氧化碳、二氧化硫、氮氧化合物年排放量分别约为3305.92、28.67、12.72 t,为区域节能减排起到了积极作用。2)在合理安排运贮灰路径的情况下,按照每月清洗1次光伏组件的频率,该光伏电站的年发电量并无减少迹象,说明在此类区域建设光伏电站具有可行性。

跨坐式单轨大坡度隧道大功率火灾排烟方案研究

[目的]跨坐式单轨隧道因火灾功率增大,坡度增陡,导致火灾临界风速增大,排烟设备配置增加,需对跨坐式单轨大坡度隧道和大功率火灾下的排烟方案进行研究。[方法]建立1∶20缩尺模型试验平台,计算不同火源热释放率和不同坡度下的隧道临界风速。采用SES(地铁环境模拟)软件建立跨坐式单轨隧道火灾一维数值计算模型,计算不同坡度隧道所需排烟设备配置。[结果及结论]根据模型试验得到跨坐式单轨隧道在20 MW大功率火灾下的临界风速值:坡度为-6%、-3%、0%、3%、6%时,对应火灾临界风速分别为3.55 m/s、3.33 m/s、2.91 m/s、2.57 m/s、2.46 m/s;车站隧道风机配置风量与坡度呈线性相关:坡度为0%时,单台隧道风机风量约75 m^(3)/s;坡度为-6%时,单台隧道风机风量约110 m^(3)/s;坡度为6%时,单台隧道风机风量约46 m^(3)/s。针对洞口隧道,洞口处射流风机配置可通过车站隧道风机结合隧道坡度反算得到;针对大坡度隧道、大功率火灾,向上坡和向下坡排烟时对应的设备配置差异较大,提出优先选用向上坡排烟的方案,以减少设备投资。

双馈风电场故障穿越控制策略对风火打捆系统暂态稳定性影响及提升控制策略

为平抑风电波动,提高输电通道利用率,大规模风电集中外送主要采用“风火打捆”系统形式。风火打捆系统中风电与火电动态相互作用,并且远距离输送到负荷中心,致使暂态稳定性问题突出。该文首先根据故障期间双馈风电场电流源模型,构造了风火打捆系统单机等值模型的功率特性方程;然后,应用等面积定则近似解析分析了故障期间无功比例系数和有功电流对系统加速面积的影响,揭示了故障期间不同无功比例系数和有功电流对暂态稳定的影响机理,并应用上述理论分析结果提出了改善故障期间风火打捆系统暂态稳定性的控制策略;最后,在PSCAD/EMTDC电磁暂态仿真软件上建立风火打捆系统模型,并验证了理论分析的正确性。

大型火力发电厂消防分区供水系统的选择

为研究大型火力发电厂消防供水系统的设计,本文从实际工程角度出发,分析现行规范下,某1台1350 MW燃煤机组和某2台1000 MW燃煤机组的消防分区供水系统的设计,得出适应于实际工程的最优方案。若大型火力发电厂存在局部高压力、低流量的最不利压力点要求,可采用串联分区供水局部升压方式;若大型火力发电厂存在高压力、大流量的最不利压力点要求,可采用管网并联分区供水方式。