The V 2 O 5 -TiO 2 catalyst produced by ultrasonic impregnation method was used to study the effects of different V loadings on the formation of SO 3 at the catalyst surface.The samples were characterized by N 2 adsorption,X-ray diffraction（XRD）,Raman analysis（Raman）,X-ray photoelectron spectroscopy（XPS）,NH 3 temperature programmed desorption（NH 3 -TPD）,H 2 temperature programmed reduction（H 2 -TPR）methods.Results show that with the increase of active component V loading,the content of V 4+ and V 3+ formed on the catalyst during the reaction also increases,and when the acidity of the catalyst surface increases,the amount of oxygen（Oα）adsorbed by the V=O bond on the catalyst surface will increase as well.After introduction of SO 2 ,it will react with V=O on the surface of the catalyst.V 5+ is reduced to V 4+ and can provide more surface that allows adsorption of oxygen（Oα）,so that SO 2 can be ox idized to VOSO 4 .On the other hand,SO 2 will also react with the [V5+] -OH groups on the catalyst surface and produce HSO 4 - ,and simultaneously,V 5+ is reduced to V 4+ .During the reaction,O 2 dose not directly provide O atoms to oxidize SO 2 but reacts with VOSO 4 to regenerate V= O,transforming V 4+ oxidized to V 5+ again.

海水湿法烟气脱硫装置排放的脱硫废水在曝气过程中,由于脱硫废水中存在部分还原性离子(SO32-、Fe2+、Mn2+等),会将脱硫过程中捕集的汞、砷离子还原为气态汞和气态砷再次释放到大气中,降低湿法脱硫系统的汞、砷脱除效率.采用曝气反应器,通过模拟实际脱硫废水的曝气过程,重点考察了温度、Cl-质量浓度、SO32-浓度、SO42-质量浓度及曝气流量对汞、砷再释放特性的影响.结果表明:随着温度的提高和曝气流量的增大,会加速汞、砷离子的还原,促进汞、砷的再释放;随着SO32-浓度的提高,会显著抑制汞的再释放,但对砷的再释放影响较弱;汞、砷的再释放率呈现先增大后减小的趋势;Cl-和SO42-可与溶液中的汞离子形成性质稳定的络合物,也可与砷离子以更稳定的化合态相结合,从而有效抑制汞、砷的再释放,并且Cl-的抑制作用比SO42-更显著.

为进一步降低现有燃煤机组烟气污染物排放质量浓度,实现大气污染物的协同深度治理,选取现役的选择性催化还原(SCR)催化剂作为研究对象,对不同条件下HCl/HBr等卤素成分对现役SCR催化剂脱硝协同汞氧化效果进行实验研究,并设计卤素溶液喷射系统,依据实验室研究结果,在现场脱硝过程中进行了不同浓度NH4Cl/NH4Br溶液喷射的工程应用与试验.结果表明:脱硝过程合理添加NH4Cl或NH4Br溶液均可有效提高现役SCR脱硝催化剂对单质汞氧化能力,HCl/HBr共同作用可以提高单一HCl在SCR催化剂表面对单质汞的氧化效果,进一步通过脱硝、下游脱硫、除尘等环保设施实现汞污染物的高效协同脱除.

针对燃煤机组尿素水解制氨系统运行过程中存在的产品气输送管道与阀门腐蚀、尿素水解器长期低出力运行、氨喷射系统磨损堵塞等典型问题,对某4×300 MW机组尿素水解制氨工程关键环节进行了优化设计.水解器宜与尿素站集中布置,水解车间和尿素溶解储存车间之间可通过设置防火墙以满足相关防火要求;水解器出力应根据机组实际运行情况设计,不宜放过大裕量;产品气输送管道采用蒸汽伴热,温度不低于140℃;稀释风宜采用冷风,配套暖风器或烟气换热器进行加热.该文的研究对燃煤机组尿素水解制氨系统的设计及安全、经济运行具有一定的指导意义.

针对某电厂300 MW燃煤机组超低排放条件下电除尘器极线出现的严重裹灰、板结现象,通过分析积灰样品烧失量、可溶性离子浓度、灰成分、粒径以及比电阻特性,结合锅炉超低排放运行特点,研究了电除尘器极线裹灰形成的关键影响因素.结果表明,低低温电除尘器极线上裹灰样品的NH+4、SO24-及灰样中SO3含量均较高,证实了电除尘器极线裹灰的主要原因是SCR脱硝系统逃逸氨与烟气中SO3反应生成硫酸氢铵,且由于低低温电除尘器工作温度较低,烟气中硫酸氢铵一旦形成后难以分解,造成电除尘器极线裹灰严重.同时由于除尘器入口烟气湿度过大,导致飞灰黏性增加,加剧了电除尘器极线裹灰与板结现象.硫酸氢铵使飞灰性质发生改变,飞灰粒度降低,同时硫酸氢铵的附着会影响电除尘器荷电,导致电除尘器除尘效率下降,进一步加剧极线积灰现象.因此,为减少电除尘器裹灰、板结现象,必须有效控制电除尘器入口烟气含水率,同时严格控制脱硝系统氨逃逸及SO3生成浓度等关键影响因素.

可凝结颗粒物(CPM)在燃煤机组烟气排放的总颗粒物中有较大占比.为分析燃煤电站环保设备对CPM的脱除效果,对某超低排放燃煤机组现有低低温电除尘、海水脱硫和湿式电除尘环保设备进、出口的CPM进行了测试.结果表明:在机组300MW高负荷和150MW低负荷条件下,上述3个环保设备能够有效脱除CPM,总CPM整体脱除率分别为97.2％和97.6％,对应排放质量浓度分别为5.58mg/m3和5.55mg/m3;干式电除尘和湿式电除尘对无机CPM的脱除效率大于对有机CPM的脱除效率;海水脱硫整体对CPM脱除作用显著,但会将海水中大量存在的Cl-离子和Na+离子带入烟气中形成一部分新的CPM,下游的湿式电除尘则能够将这些新生成的CPM脱除,最终保证了 CPM的低浓度排放.

The transfer characteristics and removal capability of Hg in ultra-low emission facilities such as selective catalytic reduction (SCR), low temperature electrostatic precipitator, seawater desulfurization and wet electrostatic precipitator in a 300 MW coal-fired boiler of a power plant were studied under different working conditions and different types of coal. The results show that under different working conditions, the total emission concentration of mercury is basically 1.16-2.90 μg/m3. The final release of mercury into the atmosphere is mainly composed of elemental mercury and a small amount of oxidized mercury, the particulate mercury was completely removed. Most mercury is removed in seawater flue gas desulfurization. The overall removal efficiency of mercury of low temperature electric precipitator, a seawater flue gas desulfurization scrubber and wet electric precipitator is 25%, 62% and 37% respectively on average. The proportion of Hg2+ is the key to affect the efficiency of mercury removal in flue gas, and the higher proportion of Hg2+ in flue gas is beneficial to obtain higher efficiency in electrostatic precipitators and seawater flue gas desulfurization devices. In the 300 MW coal-fired boiler of a power plant equipped with a selective catalytic reduction unit, a low temperature electrostatic precipitator, a seawater flue gas desulfurization scrubber, and a wet electrostatic precipitator and other ultra-low emission facilities, the average removal rate of total mercury is about 83%, which can achieve greater levels of mercury removal.

As the emission of condensable particulate matter (CPM) could exacerbate haze pollution, recently it has received more attention. In this study, CPM and its organic components were tested at different sampling sites of a flue gas purification system under the Coal 1 and Coal 2 combustion conditions, respectively. The top 10 organic components in CPM were analyzed. The results show that under the Coal 1 and Coal 2 combustion conditions, the mass emissions of CPM at the stack inlet are 4.2 and 5.6 mg/m3, respectively, and the removal efficiency of CPM by pollution control facilities after ultra-low emission transformation are 97.21% and 98.18%, respectively. In particular, the removal rates of the organic CPM by the low-low temperature electrostatic precipitator (LLTESP), the sea water wet flue-gas desulfurization (SWFGD) and the wet electrostatic precipitator (WESP) are 71.82%, 56.36% and 76.61% by average, respectively. Among them, LLTSEP exhibits general removal effect on esters, hydrocarbon and all other organic compounds. In comparison, SWFGD excels in the removal of the hydrocarbon compounds, while WESP has remarkable performance on reducing ester compounds.

The structure and functions of the maintenance management system for pipelines and their supports & hangers developed by Xi'an Thermal Power Research Institute Co Ltd have been presented.Results of practical application show that the said system reaches purpose of grasping the situation,understanding the trends,and discovering problems appeared on pipelines and their supports & hangers,enhancing the management efficiency,providing guarantee for long-term safe and economic operation of the pipeline system.

以嵩屿电厂300 MW机组静电除尘器改造工程中实际应用的极板为例,采用流固耦联振动理论及有限元方法,对静电除尘器极板的振动特性进行分析和计算,得出极板振动的普遍规律.给出的一些具有代表性的极板振型图,可为静电除尘器极板振动分析提供理论依据.