针对国华寿光电厂2号1000MW近零排放燃煤机组,在100％、45％负荷和不同NOx排放浓度下,对烟气全流程颗粒物和SO3浓度进行现场采样测试,研究了分级颗粒物中水溶性离子含量分布,并给出了前体物SO3的排放特征.结果表明:不同工况下PM10和PM2.5排放浓度分别不超过0.92mg/m3和0.24mg/m3;随着负荷的降低,颗粒物质量和数量浓度都出现下降,但粒径分布并未明显变化;随着NOx排放浓度上升,选择性催化还原(selective catalytic reduction,SCR)后和电除尘(electrostatic precipitator,ESP)后部分粒径段颗粒物浓度出现下降,尤其是ESP后0.006～0.0138μm、0.0553～5.980μm粒径段的变化趋势较为明显.SCR前后PM2.5中水溶性离子质量占比约4％,以Ca2+和24SO-为主,各粒径段质量分布相对均匀;湿式电除尘(wet electrostatic precipitator,WESP)前后PM2.5中水溶性离子质量占比约39.5％,以Mg2+、24SO-、NH4+为主,在<0.2μm粒径段中富集,不同负荷下烟气中SO3在烟道沿程上的迁移规律基本一致,SCR和ESP会导致SO3浓度增加,WFGD和WESP对SO3具有吸收作用,其排放浓度为1.2～1.9mg/m3,综合脱除效率为45.2％～65.1％.

"世界一流企业创建示范工程"是"国企改革三年行动"系列专项行动之一,旨在加快建设一批产品卓越、品牌卓著、创新领先、治理现代的世界一流企业.作为国务院国资委选定的11家"创建世界一流示范企业"之一,国家能源投资集团有限责任公司(简称国家能源集团)按照"国企改革三年行动"部署和国务院国资委"三个领军、三个领先、三个典范"的"三个三"创建要求,制定"一个目标、三型、五化、七个一流"发展战略,探索形成对标一流、创建一流、展示一流、验证一流、推广一流"五步循环"模式(见下页图1),显著增强了企业竞争力、创新力、控制力、影响力和抗风险能力.在与法国电力公司、意大利国家电力公司、瑞士嘉能可等国际先进企业对标中,国家能源集团连续三年位居第三,综合实力处于全球同行业领先水平.

汽轮发电机组高位布置技术可以缩短电厂高温蒸汽管道,是未来700℃超临界燃煤机组减少镍基合金材料使用的有效途径之一.但是汽轮发电机组高位布置技术在国际上尚无成功经验可参考,特别是汽轮发电机组基础的振动特性、抗震性能等有待深入研究.该文依托2×660MW汽轮发电机组高位布置工程,建立汽轮发电机组基础和主厂房结构的缩尺试验模型,采用三点空间激振、多点空间测量的方法分析了基础台板的自振特性,采用专业软件预测多点扰力共同作用下基础的强迫振动响应,并与数值分析结果和控制标准进行对比.结果表明,结构固有频率分布主要集中在20Hz以内,40Hz以后的高阶固有频率明显减少,这种分布为机组提供了较好的运行环境;在机组启动过程中尽量避开机组的临界转速频率,避开率超过10％;强迫振动下台板基础的扰力点和非扰力点的最大线位移、最大振动速度满足规范限值.通过合理设计台板基础下方的弹簧隔振系统,可较好控制汽轮机基础的振动.研究结果为汽轮发电机组高位布置工程设计提供了依据.

为探究中国超低排放燃煤电厂汞及其他有害痕量元素未来标准制定的可行性及建议,综合比对了中国与欧盟、美国等发达国家燃煤电厂大气痕量元素排放标准限值,并基于燃煤电厂现场测试相关文献调研分析,系统地评估了中国燃煤电厂汞及其他9种典型痕量元素(砷、铅、硒、镉、铬、锑、钴、镍和锰)的排放现状.结果表明:与美国、欧盟、加拿大等发达国家相比,目前我国燃煤电厂大气污染物排放标准限定的痕量元素污染物种类较为单一(仅规定了烟气汞及其化合物排放限值,≤30μg/m3)且排放标准限值较为宽松;在全国燃煤电厂已普遍完成超低排放升级与改造的新形势下,现行的《火电厂大气污染物排放标准》(GB13223-2011)已难以起到对燃煤电厂大气汞及其他痕量元素排放控制的实际限制作用和对先进新技术的示范引领作用.作为世界上的最大燃煤消费国,中国燃煤电厂每年消耗煤炭占中国煤炭消费总量的一半左右,是国际社会和《关于汞的水俣公约》重点关注的排放源.因此,推动燃煤电厂大气汞排放标准限值的修订及其他有害痕量元素排放标准的制定,对于保护生态环境和公众健康及国际履约均具有较大的可行性及重要的现实意义.

发展清洁高效燃煤发电技术是我国改善民生和建设生态文明的必然要求,也是现代化能源体系建设的重要组成部分.依托国华锦界电厂三期扩建工程的2×660MW超超临界、直接空冷发电机组,通过开展主厂房结构、汽轮发电机组弹簧隔振基础及主要蒸汽管道布置等技术研究,形成了完整的汽轮发电机组高位布置工程设计方案.相对于常规燃煤电厂布置,高位布置可以缩短高温蒸汽管道和汽轮机至空冷凝汽器间的排汽管道,节约管道材料成本,为700℃先进超超临界燃煤技术发展提供技术储备和先导工程.

神华煤储量丰富,具有低灰、低硫、中高热值、易燃等特性,存在灰熔点低,易结焦、爆炸等难题.从安全和清洁2个维度总结了神华煤安全燃烧、清洁利用技术及创新实践.分析了神华煤燃烧、结渣及掺烧特性,探讨了大容量锅炉结渣防治技术和燃烧系统设计、运行关键技术,提出了大容量煤粉锅炉燃用神华煤的炉膛设计选型准则,实现了神华煤型号标准化.提出了燃煤锅炉烟气污染物排放达到天然气燃气轮机组排放限值的“近零排放”企业标准,开发了除尘脱硫脱硝脱汞核心技术,率先在燃用神华煤的大容量锅炉上应用推广.结合50 000 m3/h燃煤烟气污染物全流程控制中试平台试验研究,形成了宽温度窗口脱硝、湿式机电耦合除尘等新技术,获得了烟尘,SOx,NOx和汞的排放特征及多污染物协同控制规律;通过燃煤锅炉示范应用,实现烟尘,SO2,NOx和汞排放质量浓度分别不高于1,10,20,0.003 mg/m3;探索并提出了“1123”生态环保排放限值,分析了燃煤烟气污染物减排效果.未来将持续开展新一代高效发电、烟气多污染物一体化脱除及资源化回收、非常规污染物深度脱除和CO2“近零排放”等技术的研发与应用.

在水平管式炉中O2/CO2条件下对山西吕梁烟煤煤泥进行燃烧实验,研究颗粒直径及氧气体积分数对预干燥煤泥球团燃烧特性的影响.采用热电偶测量煤泥球团燃烧过程中内部温度的变化,并通过高清摄像机同步记录预干燥煤泥球团的燃烧过程.在炉温为800℃、氧气体积分数分别为10%、20%、30%、40%以及50%的条件下,对6～12mm范围内4个不同直径的煤泥球团进行燃烧实验研究.结果表明:不同氧气体积分数下的预干燥煤泥球团呈现出不同的着火方式;煤泥球团内部达到的最高温度随着氧气体积分数的提高而提高,但与煤泥球团直径关系不大;同一粒径下,富氧燃烧条件有助于煤泥的燃尽;煤泥着火延迟时间随氧气体积分数的提高而减少.

The evolution processes of the structure and morphology of coal slime spherical particles in the process of combustion in an air atmosphere are examined in this work. A high-definition camera was used to capture changes in the macrostructure of the particles in the process of combustion, and a large amount of educt at the stage of homogeneous combustion was studied. The main component of the educt was graphite, as determined by X-ray diffraction(XRD), which demonstrated the process whereby the organic carbon molecule structures are transformed from a complicated and disordered condensed aromatic nucleus macromolecular structure to ordered graphite molecules with simple structures inside coal slime particles. Using a conducting N-2 adsorption test and analysis, this study found that there were a number of mesopores and a handful of micropores inside the coal slime particles. The pore structures experienced a process that varied from complicated at the initial moment to simple, to complicated and finally to simple. Scanning electron microscope (SEM) photos proved the change process of the above pore structures and found the phenomenon whereby pyrolytic products filled the pores at the stage of homogeneous combustion.

In order to achieve the goal of ultra-low flue gas emission,a series of retrofit projects have been carried out on the 300 MW subcritical natural circulation coal-fired unit of Sanhe Power Generation Co.,Ltd.,such as low NOx burner modification,SCR denitration modification,low-low temperature economizer installation,high frequency power source modification for the electrostatic precipitator (ESP),efficiency improvement and tubular demister installation for the WFGD absorber,as well as the installation of wet ESP (WESP).Taking the unit as the study object to explore the changes of the mercury concentrations in the WFGD and WESP wastewater after the retrofits,the makeup water and discharge water of both the FGD absorber and WESP are sampled to analyze the mercury contents.The results show that due to the low mercury content in coal,limestone and the makeup water,the mercury concentration in WFGD and WESP wastewater is also very low which ranges between 0.140 and 0.468 μg/L and between 0.094 and 0.102 μg/L respectively.The mercury contents in the 52 m3/h WFGD discharge water increase by 1.75 to 5.50 mg while no significant changes of the mercury concentration is observed in the WESP discharge water.

在近临界压力区,对垂直上升光管的临界热流密度(CHF)进行了试验研究.试验参数范围:压力18~22MPa,质量流速310~550kg·m-2·s-1,进口过冷度5~10℃.试验段的管径和壁厚为30mm和5.5mm.试验得出了各工况条件下光管壁温分布规律;分析了各参数对传热特性的影响;分别拟合出正常传热和传热恶化区域传热系数的计算式;拟合出了CHF的计算式并与4个典型的CHF计算式进行了对比;分析了各试验参数对CHF的影响;探讨了传热恶化产生的原因和汽泡大小的关系.试验结果表明:压力越靠近临界压力,质量流速越小,传热恶化越早发生;截面位置越靠前,发生传热恶化的干度越小;该试验中传热恶化以核态沸腾(DNB)传热恶化为主.

随着火电厂大气污染物排放标准要求日益严格,循环流化床(circulating fluidized bed,CFB)机组大气污染物排放控制运行综合优化的研究成为重点.以CFB机组"炉内脱硫+烟气SNCR+尾部湿法脱硫"的大气污染物排放控制技术路线为例,对炉内脱硫、湿法脱硫、脱硝和综合电耗等进行了经济性分析,确立了CFB机组大气污染物运行优化技术路线.结合活性石灰石量、煤质含硫量校正、SO2及O2预测模型,提出了CFB机组炉内脱硫动态优化控制方案,克服SO2在动态运行过程中瞬时值超限的控制难题.该文提出的CFB机组大气污染物运行优化技术路线和炉内脱硫动态优化控制方法均在实际机组进行了运行试验,验证了其可行性.

To develop supercritical circulating fluidized bed (CFB) boiler is objective of international CFB circles because supercritical CFB boiler combines the advantages of CFB combustion of low cost emission control and supercritical steam cycle of high efficiency of power generation.It is also most important for low rank coal utility.With the support of High Technology R&D Program (863) and Key Project of the National Research Program of China,Chinese researchers investigated systematically the issuers of supercritical CFB boiler development.And the huge theoretical and engineering challenges from 300MW subcritical natural circulation leaping to 600 MW supercritical once through are comprehensively broken.And the first 600MW supercritical CFB boiler and its auxiliaries were successfully developed and demonstrated in Baima Power Plant,Shenhua.Then the investigation results have been successfully expanded into 350MW supercritical CFB boilers design and have been commercialized widely.These studies provide the basis for the development of ultra-supercritical CFB boiler.Now,the key technologies such as heat deviation,ultra-low emission,and low electric power consumption are being investigated.And some preliminary achievements has been made.

This paper,based on on-site monitoring and sampling data in Dagang coal-fired units retrofitted with ultralow emission,discusses the characteristics of emission of pollutions (PM,SO2,NOx,Hg).The results indicated that the PM,SO2 and NOx emission concentrations of 4 renovated coal-fired units were respectively less than 5,35 and 50mg/m3 for a long-standing period,reaching ultra-low emission standard.During mercury sampling monitoring,57.5％ Hg is contained in ash,34.1％ Hg in gypsum and 8.3％ Hg emitting from chimney respectively after the coal combustion in 3 # coal-fired unit and pollution process and control unit.Besides,SO22 removal efficiency of FGD was 97.9％,NOx removal efficiency of SCR over 90％ during mercury sampling monitoring.

Based on the 30 B mercury monitoring methods provided by the US EPA,mercury emissions and distribution of a 300 MW coal-fired power plant were compared before and after conversion to ultra-low emissions,which include retrofitting with a low NOx burner,SCR,ESP with high frequency power source,FGD with tubular mist eliminator and adding low temperature economizer and WESP.The mercury content of the coal was 49 μμg/kg,and the mercury concentration at the stack entrance was 1.87 μg/m3 before retrofitting.After the air pollutant control devices,35％ of the mercury from coal combustion remained in ashes,29.5％ of the mercury in gypsum,and 35.4％ of the mercury was discharged from the stack.After ultra-low emissions retrofitting,mercury content of the coal was 30 μg/kg,and the mercury concentration at the stack entrance was 0.46 iμg/m3.After coal combustion and pollutant control devices,36.1％ of the mercury remained in ashes,55.2％ of the mercury in gypsum,and 8.7％ of the mercury was discharged from the stack.After retrofitting,a big proportion was captured by APCD system compared with before retrofitting.The capture efficiency was increased 1.5 times.This might be due to the higher oxidation rate from elemental mercury to oxidized mercury in the SCR system and better capture of oxidized mercury in the WFGD system.WESP did not show any significant effect on the mercury capture efficiency.

2015年3月,经国务院授权,国家发展改革委、外交部、商务部正式联合发布《推动共建丝绸之路经济带和21世纪海上丝绸之路的愿景与行动》,这是新一届中央领导集体从全局高度和长远角度出发提出的重大战略构想,对于保障国家能源安全、实现地区繁荣、促进企业发展具有重要的意义.

Shenhua coal is one of the most severely slagging coal sorts in China.The slagging prevention technologies needed to adopt for burning Shenhua coal in the tangential firing boilers have been analysed,and a comparison with corresponding slagging prevention technologies for burning bituminous coal with low ash fusing point at home and abroad being carried out.Results of comparison show that the slagging phenominon in boilers burning Shenhua coal can be effectively avoided under condition of adopting low volumetric heat capacity in the furnace,suitable mixedly burning,as well as corresponding measures in operation,such as lower temperature of the primary air,higher ratio of air to coal,the oxygen content at furnace outlet to be controlled to 3%,and the fineness of pulverized coal controlled to R906% etc..The said measures are more effective than that adopted by companies at abroad for burning bituminous coal with low ash fusing point.

Although AC TCSC (thyristor controlled series capacitor and DC transmission technology improve transient state stability and sending power of circuits,as well as strengthen interconnected grid stability,they bring potential trouble like torsional vibration to shafting of generating sets.This article analyzed the causes for the above mentioned trouble,introduced analysis methods and countermeasures of AC-DC system synchronous resonance or oscillation,and problems might face in practice.