300MW机组锅炉燃烧系统低氮改造与效果分析

为了保护环境,进一步提高锅炉热效率,根据某300 MW机组锅炉运行状况,分析了燃烧系统存在的问题,提出了燃烧系统低氮改造措施。经试验验证,锅炉低氮改造后,锅炉NOX排放量大幅减少,排放浓度降到了280 mg/m3,锅炉热效率也略有提升。     

改进型1030 MW超临界机组高加撤出的保护探讨及优化

某改进型1030 MW机组在国内属首次创新应用,制造厂家认为当高加系统撤出后,由于通流的增加可能导致过负荷从而影响机组安全运行,原机组保护逻辑中规定了当高加撤出后若机组负荷大于1030 MW延时1 min,或大于1106 MW延时10 s后触发机组主保护。上述定值并未经过实际工程考验,为了提高机组运行的可靠性和安全性,在对保护逻辑进行确认和优化的基础上,安排了800 MW工况下的高加跳闸试验。试验后对相关数据进行了分析核算,进一步完善了相关控制逻辑和定值,确定了该机组高加撤出保护的实施方案。同时也对各型机组在高加跳闸工况下的危险点进行了分析总结。     

300MW直接空冷机组空冷系统增容改造分析

为了提高机组真空度,改善机组运行经济性,某火电厂300 MW直接空冷机组进行了空冷系统增设空冷散热器的增容改造.改造后,夏季平均工况下汽轮机排汽压力为17.8 kPa,比改造前设计排汽压力(24.9 kPa)降低了7.1 kPa.对比分析了改造效果,认为增容改造有利于降低汽轮机运行背压,提高了机组运行经济性.     

Temperature Dependence of Microwave and THz Dielectric Response in Srn + 1TinO3n + 1 (n = 1–4)

The microwave, near-millimetre and infrared (IR) dielectric response of Sr_{n + 1}Ti_nO_{3n + 1} (n = 1–4) Ruddlesden-Popper homologous series was studied in the temperature range 10 to 300 K. Remarkable softening of the polar optical mode was observed in Sr₄Ti₃O₁₀ and Sr₅Ti₄O₁₃ which explains the increase in microwave permittivity and dielectric loss upon cooling. However, both samples have a distinct content of SrTiO₃ dispersed between SrO layers. It is proposed therefore that the observed soft mode originates from the SrTiO₃ microscopic inclusions.     

300MW机组电液两种旁路的分析与比较

对 30 0 MW机组以 SIEMENS和 SULZER两家公司为代表的电动和液动旁路进行了分析与比较 ,包括阀门组成、驱动装置、控制系统、设计功能、可靠性和抗燃油的使用等方面 ,指出两种旁路各有优缺点。经严格调试 ,使之与机组实际情况相适应 ,无论是液动或电动旁路 ,自动和保护功能的发挥 ,保证了机组的启动和安全运行。鉴于我国的实际情况 ,旁路的设置应以实用、可靠、少投资为原则 ,强调其可靠性和可操作性 ,指出设计以启动功能手操为主的电动旁路 ,具有较为现实的意义。     

Interpolymer radical coupling: A toolbox complementary to controlled radical polymerization

The current review focuses on the relevance and practical benefit of interpolymer radical coupling methods. The latter are developing rapidly and constitute a perfectly complementary macromolecular engineering toolbox to the controlled radical polymerization techniques (CRP). Indeed, all structures formed by CRP are likely to be prone to radical coupling reactions, which multiply the available synthetic possibilities. Basically, the coupling systems can be divided in two main categories. The first one, including the atom transfer radical coupling (ATRC), silane radical atom abstraction (SRAA) and cobalt-mediated radical coupling (CMRC), relies on the recombination of macroradicals produced from a dormant species. The second one, including atom transfer nitroxide radical coupling (ATNRC), single electron transfer nitroxide radical coupling (SETNRC), enhanced spin capturing polymerization (ESCP) and nitrone/nitroso mediated radical coupling (NMRC), makes use of a radical scavenger in order to promote the conjugation of the polymer chains. More than a compilation of macromolecular engineering achievements, the present review additionally aims to emphasize the particularities, synthetic potential and present limitations of each system.     

亚临界锅炉汽包水位计偏差大探析

基于汽包水位测量原理进行误差分析,比对现有汽包炉水位计特性,进行有针对性的调整和改造,在很大程度上可以减少汽包水位计的偏差,提高汽包水位测量的准确度,减少因水位计测量不准、偏差大而引起的安全事故,对于提高涉网机组的安全性有较大的现实意义。     

200MW汽轮机左右油动机不同步原因及其消除对策

指出了200MW汽轮机左右油动机不同步对汽轮机运行的经济性和可靠性所带来的危害，归纳了影响油动机同步的因素和改进措施，同时还建议采取闭环控制以替代目前的开环控制。     

不同启动工况对国产200MW汽轮机转子寿命的影响

阐述了不同启动工况对国产200MW汽轮机转子寿命的影响。并以朝阳电厂1号机试验资料为依据,分析了机组热态启动时再热蒸汽参数对中压缸转子寿命的影响。     

无控制工质调节系统在200 MW汽轮机组上的应用

介绍了无控制工质调节系统的组成、特点以及在200MW汽轮机组上的成功应用。通过杠杆驱动油动机错油门的控制方式为调节系统改造提供了新的途径和手段。