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.

Sliding Mode Predictive Control of Main Steam Pressure in Coal-fired Power Plant Boiler

Since the combustion system of coal-fired boiler in thermal power plant is characterized as time varying, strongly coupled, and nonlinear, it is hard to achieve a satisfactory performance by the conventional proportional integral derivative (PID) control scheme. For the characteristics of the main steam pressure in coal-fired power plant boiler, the sliding mode control system with Smith predictive structure is proposed to look for performance and robustness improvement. First, internal model control (IMC) and Smith predictor (SP) is used to deal with the time delay, and sliding mode controller (SMCr) is designed to overcome the model mismatch. Simulation results show the effectiveness of the proposed controller compared with conventional ones.

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。

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.

Demands for Coal-fired Power Will Reach New High

According to the new report released by the International Energy Agency,as the pandemic starts to mitigate and the global economy gradually recovers,demand for power has been rising.In 2021,the world’s coal-fired power generation increased by 9%over the previous year,while in 2020 power generation fell by 4%.The report shows that the rising demands for power,coupled with inadequate low-carbon power generation have made many developed economies more dependent on fossil fuel power.The rise of natural gas prices to a historical high has also stimulated demand for coal.

COMPARATIVE RESEARCH ON THE CHARACTERISTICS OF THE FLYASH FROM COAL REFUSE-FIRED AND COAL-FIRED POWER PLANTS

The physical,chemical and mineral facies properties of the flyash from Xiezhuang Coal Refuse Fired Power Plant have been studied by means of naked eyes,microscope,chemical composition analysis and XRD analysis,and compared with that of the flyash from Taian Coal Fired Power Plant.The result shows that the flyash from coal refuse fired power plant is of better quality in making construction items,for being brighter in color,fine and high activity.Some ways of comprehensive utilization of the ash have been suggested in this paper.

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.

The flue dust emission of the coal fired power plants in Zhejiang Province attains target

According to statistics, the average dust collection efficiency of flue gas emission in the large and medium- sized power plants in Zhejiang Province at present has attained higher than 97% which surpasses the 95% standard as stipulated by the Ministry of Electric Power. The dust collection efficiency of the Beilungang Power Plant has already attained 99.92%. In recent years, Zhejiang Electric Power Corporation has stipulated that all the newly constructed generating units shall be equipped with high efficiency electrostatic precipitator (ESP) while the existing power plants shall speed up their renovation work for their dust collectors. In combination with the fourth stage project of the Taizhou Power Plant, the improvement work of the dust

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.

Effect of Carbon Price Floor on Levelised Cost of Gas-Fired Generation Technology in the UK

The UK government implements carbon price floor to provide long-term incentive to invest in low-carbon technology, thus, fossil-fuel power plants have to face increasing carbon price. This report addresses the effect of carbon price floor on levelised cost of gas-fired generation technology through the levelised cost of electricity (LCOE) ap-proach with the estimation of carbon price floor. Finally, the comparison of levelised cost of electricity for all generation technology in the UK will be shown and discussed.

大型燃煤发电机组低碳技术进展

当前我国碳排放总量约110亿t,其中约40%的CO_(2)由燃煤机组产生,如何降低燃煤发电机组的碳排放是实现双碳目标的关键。针对燃煤发电机组大规模减碳技术,重点介绍低碳/零碳燃料替代技术(生物质、污泥、氢/氨等)和CCUS技术的研究进展:燃煤电厂耦合生物质包括直接耦合和间接耦合,但均受制于生物质原料供应和价格,生物质“种植—收割—转运—储存—预处理—燃烧”全链条控制掺烧模式可有效解决上述问题。660 MW机组掺烧试验表明,CO_(2)排放可减少77.25万t/a;市政污泥含水率高达80%,进入锅炉前需干化处理,目前蒸汽或烟气干化均存在投资运行成本高、干化后的污泥水分较大且有臭气等问题,导致掺烧比例一般低于8%。基于生物质热源的污泥炭化技术可直接在污水厂生产无臭污泥炭,热值达10.26 MJ/kg左右,电厂掺烧比例可提高至20%~30%;掺烧氢/氨燃料需解决大比例掺烧下氨逃逸和NOx排放问题,国内已开展皖能集团300 MW和国家能源集团600 MW氨煤掺烧实验,通过燃烧调控可在NOx排放略微增加的情况下实现较高的NH3燃烬率,但商业化推广还受制于氢/氨成本;燃烧前脱碳技术(IGCC电站)的商业化运行案例极为有限,由于高居不下的成本,国外多个示范项目均已停运,推动该技术商业化需解决建设成本、发电成本和设备可靠性等问题。燃烧中碳捕集包括富氧燃烧和化学链燃烧,由于空分、再循环等过程能耗,常压富氧发电效率比空气燃烧低8%~12%,从常压富氧到加压富氧可进一步提高净发电效率;我国已建成全球最大的4 MW化学链燃烧示范装置,该技术也有望应用于气化领域;燃烧后碳捕集目前以溶液吸收技术为主,固体吸附技术的再生能耗更低,但大规模商业化需要继续降低能耗和成本。

固体氧化物电解槽辅助煤电机组深度调峰技术可行性研究

常规的煤电机组灵活性改造方案,难以消除频繁快速变负荷对热力系统造成的潜在寿命折损与设备安全风险。为提高煤电机组参与深度调峰的长期安全性与经济性,以某国产超超临界二次再热1000 MW燃煤机组为应用对象,提出了基于氢储能系统的煤电机组“健康调峰”技术路线,并论证了调峰煤电制氢的间接碳减排意义。在此基础上,分析比较了不同制氢工艺与煤电厂生产条件的匹配程度,认为固体氧化物电解槽(SOEC)制氢为综合最优方案,据此给出了SOEC耦合煤电调峰的原理性设计方案,最后以年度负荷曲线对新方案进行了财务分析。计算结果表明,示例机组自第6年起每年可获得1.07亿元/年的净利润,每年减少碳排放281.92 t,同时获得设备延寿、降耗减碳等其他收益。相关结论对于指导调峰煤电机组的健康安全运行具有参考意义。

“双碳”目标下燃煤电厂灵活性改造及政策建议

双碳目标下,以新能源为主的可再生能源将实现规模化发展,煤电将向基础保障性和系统调节性电源并重转型。推动燃煤电厂灵活性改造,是增加新能源消纳能力、推动新能源高质量发展的重要举措。本文系统介绍了中国的煤电现状及新定位,梳理了中国“三改联动”中煤电灵活性改造进展情况,评价了灵活性改造实施效果,聚焦影响煤电机组灵活性运行的主要技术问题,研究分析了灵活性改造典型技术路线及其经济性。借鉴欧美提升煤电灵活性的市场经验,从加强规划引导、完善支持政策、发挥市场作用、确保运行安全等方面提出了推进灵活性改造、促进煤电产业转型发展的政策建议。

中国燃煤发电水足迹时空特征研究

中国燃煤发电行业需要消耗大量水资源。基于生命周期方法,建立了中国燃煤发电水足迹评估模型。该模型包括煤炭开采、煤炭加工、煤炭运输、燃煤发电和电力输送五个阶段,水足迹不仅考虑了直接水足迹,还有间接水足迹。基于该模型,定量分析了2000—2020年中国燃煤发电整个生命周期的用水量和废水排放对环境的影响,中国各省份燃煤发电的水足迹以及跨省煤电运输所产生的虚拟水的时空变化特征。结果显示:从时间上看,2000—2020年,中国燃煤发电总水足迹逐年上升,从160亿立方米增加到661亿立方米。单位水足迹处于先上升后下降的趋势,2015年达到最大值15.6 m3/MW·h。期间,灰水足迹占比较大,为76%~83%。整个生命周期中,间接水足迹占总水足迹的36%~45%。从空间上看,2020年,内蒙古、安徽、宁夏、陕西和新疆是主要虚拟水输出省份,而内蒙古、山西、山东和新疆是2000—2020年水足迹增长最多的省份。研究结果以期为我国煤炭和水资源高效利用以及水环境管理提供重要借鉴。

某核电厂电气仪控房间火灾排烟温度分析

对某核电厂电气厂房的2个电气仪控房间进行了火灾排烟温度模拟分析。模拟计算了排烟系统不同时刻启动时,这2个防火空间室内空气温度的变化情况。结果表明:排烟系统启动后房间空气温度迅速降低,然后逐渐升高,最后随着火灾热释放速率的降低而逐渐降低;对于手动启动的排烟系统,需及时启动才能有效排除火灾中的烟气;需合理设置排烟防火阀,以保护排烟风机等。

双碳背景下燃煤电站掺氨燃烧研究进展与展望

在“双碳”背景下,选择低碳燃料氨对燃煤电站的改造显得尤为重要。该文首先介绍氨的基本物性及其掺烧的优势,随后针对氨煤掺烧技术的新应用,按照燃煤设备的输出功率分类,从微/小型掺氨燃烧器、千瓦级燃煤掺氨燃烧系统、兆瓦级燃煤掺氨燃烧系统,大型燃煤电站掺氨燃烧系统,介绍当前的研究进展。最后,对燃煤电站掺氨燃烧的前景进行分析与展望。燃煤电站掺氨燃烧可大幅降低碳排放,但可能带来NO_x排放问题,通过空气分级、氨预分解、调节氨掺入位置和比例等手段,可以有效控制NO_x排放;目前,仍需解决煤/氨气固两相燃料反应性差异大、NO_(x)浓度高、缺乏大容量高比例燃烧器技术,以及突破“大型给氨+清洁燃氨+灵活运行”的关键技术。

“双碳”目标下我国燃煤发电转型升级发展路径

统筹推进我国燃煤发电(简称“煤电”)转型升级,推动煤电功能定位转变,是实现“双碳”目标和加快构建新型电力系统的重要任务。针对我国燃煤发电转型升级的迫切需求,该文分析当前我国煤电的装机规模及其特点,评估了煤电的能耗、灵活性和碳排放3方面的发展水平,解析我国煤电未来发展方向,重点探讨了煤电热力系统重构、煤电与储能融合、煤电与其他能源及碳捕集、利用与封存(carbon capture,utilization and storage,CCUS)的互补集成、“安全、高效、清洁、低碳、灵活”多目标协同4个方面的发展路径,提出新一代煤电高质量发展的基本思路。面向新形势下“安全、高效、清洁、低碳、灵活”的发展目标,未来我国煤电机组需要开展热力系统深度重构,通过热力系统的大范围重新设计、优化或改造,提高机组效率和灵活性、降低能耗和碳排放;可以将储热、飞轮、压缩空气等储能与煤电系统有机融合,突破煤电机组自身调节潜力约束,拓宽煤电机组的调节区间,提升机组变负荷能力和效率;充分利用煤电机组内丰富的物质流和能量流,可将煤电与其他能源或系统在多个环节匹配耦合,实现整体的多能互补能量梯级利用,提升总体能效与低碳水平;应重点从设计和运行两个维度实现多目标协同,在设计阶段注重高效清洁技术的集成与智能化、自动化,在运行过程中采用智能化、精细化控制策略。该文旨在增强煤电战略价值认知,为我国煤电转型升级提供理论参考和路径建议,助力新一代煤电在推进“双碳”进程和构建新型电力系统中发挥更广泛、更积极作用。