新型环保节能烟囱的技术特征和运行原理

提出了一种新型烟囱技术,即利用旋涡流动的空气动力学特点,妥善地解决了湿法脱硫后烟囱内壁的腐蚀问题.同时,新型烟囱还具有更好的节能、环保效果.系统地论述了新型烟囱技术的基本内涵、主要技术优势、设计要点与运行原理,从空气动力学原理和工程实践两方面说明新型烟囱技术的合理性与实践可行性.     

泡沫玻璃砖在烟囱防腐中的应用

火电厂燃煤烟气中存在一定量的SO3,会显著降低烟气的酸露点。由于湿法脱硫后烟温低于酸露点,烟气中的SO3与水蒸汽形成的硫酸蒸汽会凝结下来,造成混凝土烟囱的低温腐蚀。以2×135MW机组烟气脱硫技改工程湿烟囱防腐为例,详细介绍了烟囱内衬泡沫玻璃砖防腐的施工工序、技术要求及注意事项。     

湿烟囱内衬防腐材料的选择

对国内湿烟囱防腐中应用较多的材料的化学成分、耐酸腐蚀性能、物理性能、焊接性能进行了比较分析,认为从技术角度而言,镍基合金优于钛金属.     

新型烟囱节能、环保、防腐技术特征分析

对新型烟囱技术特征和流场结构的分析认为:由于切向进气,烟气形成旋涡,流动阻力低于普通烟囱,压力损失减少,所以更节能;流场中心形成负压,水、雾等比尘粒小,但比空气大(重)的轻质组分集中在中轴地带随烟气排出,不会腐蚀内壁;因为旋涡流动的存在,提升了烟气排放高度,有更好的环保效果.     

湿法烟气脱硫系统设置与取消GGH探讨

对设置与取消GGH的石灰石—石膏湿法烟气脱硫系统的性能检测指标进行对比分析,提出无GGH烟气脱硫系统可通过一种新的净烟气再热方式来提高烟气抬升高度,并减轻对烟囱的腐蚀。     

脱硫装置采用钢与混凝土组合湿烟囱探讨

烟气脱硫装置采用湿烟囱排放可降低工程投资,降低电耗、水耗和年运行费。介绍了一种钢与混凝土组合湿烟囱,烟囱底部是混凝土部分,上部是钢烟囱;烟囱采用内壁涂抹环氧乙烯基玻璃鳞片树脂进行防腐。     

火力发电厂烟囱选型

以铁岭发电厂二期2×600MW超超临界机组工程240m烟囱型式的选择为例,在简要介绍烟囱的一般型式、烟囱的选型原则和国内烟囱选型情况的基础上,进行比选并确定最终方案。     

燃煤电厂脱硫烟囱防腐技术创新和应用探讨

通过对现行燃煤电厂脱硫烟囱防腐技术分析,总结了脱硫烟囱防腐失效的原因,提出了脱硫烟囱防腐的技术创新思路。简要介绍了采用自硫化丁基橡胶防腐衬里对燃煤电厂脱硫烟囱进行防腐的可行性和成功案例。     

关于烟囱选型的办法

从环保、安全、经济等多种因素讨论了火电厂烟囱选型问题，如烟囱座数、烟囱筒数及套筒式烟囱等。     

石横一期烟囱冲洗水及排液系统改造

介绍了石横电厂一期烟气脱硫技改项目中烟囱及入口烟道排液系统改造情况,论述了烟囱及烟道排液系统改造要点、运行方式,提出了烟囱排液系统的改造方案。     

A study of the corrosion products of mild steel in high ionic strength brines

The corrosion layer on steel surfaces that formed after exposure to waste isolation pilot plant (WIPP) brines under anoxic conditions was characterized for chemical composition, thickness and phase composition. The chemical composition of the corrosion layer was determined both by X-ray photoelectron spectroscopy (XPS) and by chemical analysis of acid solutions used to remove the corrosion layer. Atomic force microscopic (AFM) images indicated that the brine-corroded surface layer shows extensive granulation along the contours of the steel surface that is characteristic of sharp polishing marks. The corrosion layer seemed to be porous and could be dissolved and detached in dilute hydrochloric acid. The corrosion layer appears to be composed of iron oxides with some ionic substitutions from the brines. The 77 K M?ssbauer spectrum recorded for iron powder leached under similar conditions indicated the corrosion layer was comprised principally of green rust.     

Influence of MSWI bottom ash used as unbound granular material on the corrosion behaviour of reinforced concrete

The reutilisation of MSWI natural weathered bottom ash (WBA) in many applications such as road and underground constructions, embankments or as an aggregate replacement is a common practice in many developed countries. Its potential environmental risk has regularly been evaluated from the point of view of the leaching of heavy metals and metalloids. Nevertheless, the influence over steel rebar when reinforced concrete is exposed to the contact with WBA has been poorly assessed before. In this study, it has been possible to evaluate in terms of days the probability of corrosion in a common case of WBA reutilisation, which is in contact with reinforced concrete formulated with conventional Portland cement. The corrosion monitoring indicates that the probability of corrosion of steel rebar is higher than 90 % with a corrosion rate (CI) estimated to be 11.6 µm year^?1. The aggressive conditions imposed by WBA suppose an important withdrawal if the application of reutilisation involves contact with steel rebar.     

燃煤锅炉炉膛高温腐蚀原因及对策

从300MW机组锅炉水冷壁管的高温腐蚀情况出发，阐述了产生高温腐蚀的原因，并提出了切实可行的预防措施。     

臭氧在循环冷却水中缓蚀作用的研究

循环冷却水处理是工业生产中的一个重要环节。臭氧作为单一的水质稳定剂在循环冷却水中具有缓蚀作用。研究结果表明：吸附在金属表面的臭氧使金属表面从活化腐蚀状态转变为钝化状态,使金属腐蚀电位由活化电位区跃变到钝化电位区,阻止金属的溶解;同时氧的传质速率加快,也可以降低由于浓差极化所产生的腐蚀作用;对于未经预膜处理的金属,臭氧改变金属表面状态,形成一层氧化钝化膜,从而起到了缓蚀作用。     

Application of a Proposed Generic LLW Waste Package Analysis With Changing Infiltration in a Humid Environment

Corrosion of carbon steel boxes filled with low‐level radioactive waste and buried within a near surface disposal facility in a humid environment was evaluated using an integrated systems approach framework. The time to hydraulic failure from initial burial to development of holes through the wall of a given waste package from pitting corrosion was calculated for four corrosion scenarios under two different corrosion cases. The two corrosion cases chosen were a constant rate of corrosion and a slowing rate of corrosion. Corrosion rates were estimated for carbon steel buried in soil from several historical studies and related to the corrosivity and aeration profile of the soil. The scenarios were chosen to represent a range of possible conditions at current and future U.S. Department of Energy disposal facilities. For each scenario, once the time to hydraulic failure had been estimated, the amount of liquid present in each waste package at the time of failure was calculated as an estimate of leachate available for subsurface transport. The Savannah River E‐Area Engineered Trench was used as a basis for the hypothetical disposal facility. © 2016 Wiley Periodicals, Inc.     

石灰石—石膏湿法脱硫装置磨损腐蚀问题分析

分析了目前国内现有石灰石—石膏湿法脱硫装置的磨损防腐问题,简述了在运石灰石—石膏湿法脱硫装置的主要磨损腐蚀环境及相应的防护措施。     

Sulfur recirculation for increased electricity production in Waste-to-Energy plants

Sulfur recirculation is a new technology for reducing boiler corrosion and dioxin formation. It was demonstrated in full-scale tests at a Waste to Energy plant in Göteborg (Sweden) during nearly two months of operation. Sulfur was recirculated as sulfuric acid from the flue gas cleaning back to the boiler, thus creating a sulfur loop.The new technology was evaluated by extensive measurement campaigns during operation under normal conditions (reference case) and operation with sulfur recirculation. The chlorine content of both fly ash and boiler ash decreased and the sulfur content increased during the sulfur recirculation tests. The deposit growth and the particle concentration decreased with sulfur recirculation and the dioxin concentration (I-TEQ) of the flue gas was reduced by approximately 25%. Sulfuric acid dew point measurements showed that the sulfuric acid dosage did not lead to elevated SO₃ concentrations, which may otherwise induce low temperature corrosion.In the sulfur recirculation corrosion probe exposures, the corrosion rate decreased for all tested materials (16Mo3, Sanicro 28 and Inconel 625) and material temperatures (450 °C and 525 °C) compared to the reference exposure. The corrosion rates were reduced by 60–90%. Sulfur recirculation prevented the formation of transition metal chlorides at the metal/oxide interface, formation of chromate and reduced the presence of zinc in the corrosion products. Furthermore, measured corrosion rates at 525 °C with sulfur recirculation in operation were similar or lower compared to those measured at 450 °C material temperature in reference conditions, which corresponds to normal operation at normal steam temperatures. This implies that sulfur recirculation allows for higher steam data and electricity production without increasing corrosion.     

湿法脱硫系统GGH结垢原因分析及对策

介绍了GGH运行中易出现的结垢、堵塞和腐蚀等问题,并对其产生的原因进行了分析,提出了减缓GGH结垢、堵塞和腐蚀趋势的措施和建议。     

Abiotic hydrogen production in fresh and altered MSWI-residues: Texture and microstructure investigation

Long-term hydrogen generation was observed in a Bavarian mono-landfill for municipal solid waste incineration (MSWI) residues. Hydration reactions of non-noble metals, especially aluminum, predominantly produce hydrogen at alkaline reaction conditions. Microscopic investigations show that aluminum metal may occur in different forms: as larger single grains, as small particles embedded in a vitrified matrix or less frequently in blowholes together with metallic silica.Four types of corrosion texture were observed, indicating different reaction mechanisms: aluminum hydroxide rims caused by hydration reactions at alkaline reaction conditions (reaction type 1) and multiphase rims with ettringite and hydrocalumite due to the reaction of aluminum hydroxide with sulfate and chloride ions which are solved in the pore water (reaction type 2). Galvanic corrosion textures due to the electric potential difference between aluminum and embedded intermetallic Fe- or Cu-rich exsolution phases lead to two further corrosion textures: Strong hydration effects of aluminum except a border of aluminum remnant directly beside the Fe- or Cu-rich segregations were only observed in fresh samples (reaction type 3). The reaction type 4 shows a network of Al-hydroxide veins occurring along the embedded intermetallic Fe- or Cu-rich exsolution segregation pattern within the metallic aluminum grain. Metal particles enclosed in vitrified particles offers the potential for future corrosion processes.The occurrence of corrosion types 1, 2 and 3 in fresh bottom ashes indicates that these reaction mechanisms predominate during the first reaction period in the presence of chlorine in an alkaline solution. Corrosion type 4, however, was additionally observed in aged samples. Here aluminum acts as sacrificed anode implying electrochemical reaction due to electrolytic pore water. Chloride in the system keeps the reaction alive as Al-hydroxide is solved which normally builds a protection shield around the aluminum metal particles.Due to field observations and experimental results we have reasonable indications that after an initial strong formation of hydrogen the reaction time for hydrogen production in the landfill is lengthened for several decades by the presence of chloride in the alkaline pore water.     

大气污染对输变电设备的影响及防治对策

通过对受到腐蚀和发生污闪事故的输变电设备的表面污秽进行测试,分析污秽主要化学成分的来源,并结合当地环境状况,认为大气污染是造成以上影响的主要因素,污秽成分的组成受周边工业污染源所排放特征污染物的直接影响。据此从输变电工程的各个阶段有针对性地提出了防止设备腐蚀和污闪事故的对策和措施。