湿法烟气脱硫装置采用湿烟囱排放的探讨

湿法烟气脱硫装置中 ,烟气换热器的作用是降低进入吸收塔的原烟气温度 ,满足脱硫工艺要求 ;还可减轻烟道和烟囱遭受低温湿烟气的腐蚀。湿法烟气脱硫装置中换热器的设置取决于烟囱出口排烟温度。湿法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。湿法烟气脱硫装置是否采用湿烟囱排放除考虑经济因素外 ,还应考虑烟流扩散、烟羽的黑度测量、烟气携带冷凝物等问题。采用湿烟囱排放对工艺装置的设计具有一定的要求。     

三种FGD湿烟囱内衬涂层耐热性的比较

对三种国内常用FGD湿烟囱内衬涂层进行了耐高温和冷热交变试验,根据试验结果对其耐热性进行分析和比较。     

烟气脱硫改造后烟囱防腐的探讨

湿法脱硫后的烟气温度低,湿度高,烟气中各项性能指标均会发生了变化,致使烟气具有强腐蚀性,从而带来了老烟囱如何防腐的问题。文章以申能星火热电厂为例,简要分析了脱硫后湿烟气造成烟道和烟囱腐蚀的原因,并探讨了目前主要应用的几种烟囱防腐改造的措施,提出了比较可行的方案。     

湿法烟气脱硫机组烟囱防腐措施

介绍了脱硫烟气对烟囱的影响;探讨了脱硫后烟囱的选型原则,提出了脱硫后钢烟囱的防腐措施,并对内衬的选型提出了建议。     

湿烟囱防腐方案对比分析

介绍了湿法脱硫烟气对烟囱的影响,对各种湿烟囱防腐方案进行了比较分析,并提出了湿烟囱防腐方案选型建议。     

湿法脱硫烟气湿排问题分析

目前国内湿法烟气脱硫普遍采用烟气再热器(GGH)提高出口烟温，但加装GGH会使系统复杂化并增加投资及运行费用。为探求烟气湿排的可行性，研究解决烟气湿排中的相关问题，文中利用数值模拟技术，对烟气直接排放(取消GGH)时烟囱内的流场，烟羽扩散情况进行了数值模拟研究；对烟气湿排中的腐蚀问题、烟囱内的压力分布、烟气的抬升高度等问题进行了计算分析。数值计算与分析表明，湿烟囱排放会增强对烟囱的腐蚀性，需采用特殊的防腐处理；湿烟囱直接排放会降低烟气抬升高度，不利于扩散；为减少烟流下洗，增强扩散，应保证烟气的出口动量；湿烟气各项排放指标能满足环保要求。总之，设计合理的湿烟囱，湿烟气直接排放可大大降低WFGD系统的设备投资和运行费用，是完全可行的。     

火电机组烟囱脱硫防腐停运期间另设烟囱的选择

探讨了原烟囱脱硫改造期间,另设烟囱的选择方案,通过对几种不同方案的使用条件、技术经济性、运行可靠性、安全稳定性、对环境的影响等进行分析对比,提出了烟囱防腐期间另设烟囱的选择建议.     

GGH和“湿烟囱”在FGD系统中的应用比较

目前电厂烟气脱硫（FGD）系统对尾部净烟气的处理,一般采用的两种方法,即GGH（烟气再热器）对净烟气进行再热处理,和对流经脱硫吸收塔的净烟气进行直接排放的“湿烟囱”方法,通过比较笔者认为,利用GGH对净烟气进行再热处理应是FGD系统采用的基本方法。     

火电厂脱硫烟囱的结构选型

介绍涅法脱硫后烟气的特点和火电厂常见烟囱结构形式及其特点,比较烟气脱硫(FGD)系统设置与不设置烟气加热系统的优劣,从技术和经济两方面分析论证了排烟筒的材质选择及防腐处理措施,经比较推荐采用国产泡沫玻化砖钢套筒式烟囱.     

湿法脱硫后烟气对钢烟囱的腐蚀试验研究

针对北仑发电公司(北仑电厂)湿法脱硫后烟气的特点,在试验室内进行模拟,研究了不同脱硫效率和不同硫酸浓度对几种金属腐蚀速率的影响。试验结果表明,脱硫后烟气对10CrMnCuTi有强烈的腐蚀作用,有必要对脱硫后烟囱进行防腐蚀处理。酸性条件下,4种金属的腐蚀速率依次是Q235A>10CrMnCuTi>0Cr18Ni9>0Cr17Ni12Mo2,Cl-和F-能大大加速腐蚀。模拟烟囱凝结液对10CrMnCuTi腐蚀能力很强,Ti基本不被腐蚀。     

大容量火电机组湿法脱硫系统烟气加热器的应用

烟气加热器是湿式石灰石-石膏法烟气脱硫系统中的主要设备,但烟气加热器结构、造价和运行等影响因素,使某些火力发电厂湿法脱硫系统没有采用。阐述了湿式石灰石-石膏法烟气脱硫系统不设置烟气加热器存在的问题,对湿法烟气脱硫系统是否采用烟气加热器进行了经济技术分析,并结合环保要求,认为600Mw以上容量机组湿法烟气脱硫系统应设置烟气加热器。     

基于LNG与汽车尾气大温差下的温差发电研究

为了有效利用液化天然气(LNG)汽车中LNG的冷能以及排气的热能,提出利用半导体温差发电器,分析计算了LNG与发动机排气的可回收能,设计了回收利用冷能和热能的流程,计算了各个状态点的参数,建立了大温差下的多级温差发电器模型,并对其输出功率和热电转换效率进行了计算。结果表明,利用半导体温差发电器来回收LNG的冷能和排气热能的方案具有可行性;在大温差的条件下,多级温差发电器能有效地提高热电转换效率。     

Effect of oxygen gas on the decomposition of dye by pulsed discharge in water droplet spray

The influence of stresses on the magnetic properties of nonoriented electrical steels was studied. The dependence of iron loss on compressive stress was affected by grain size. The magnetic polarization J in strong magnetic fields such as 5000 and 10,000 A/m increased due to compressive stresses and decreased due to tensile stresses in samples with low Si content. Using Kerr‐effect domain observation, it was found that the reduction in J caused by tensile stresses was attributable to residual striped domains. Magnetostriction measurements in strong magnetic fields indicated that the increase in J under compressive stresses originated from the Villari effect (inverse magnetostrictive effect) due to negative magnetostriction in low‐Si materials. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 182(4): 10–18, 2013; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22320     

Influence of voltage rise time on oxidation treatment of NO in simulated exhaust gas by polarity‐reversed pulse discharge

This paper describes an experimental study of NO removal from a simulated exhaust gas by repetitive surface discharge on a glass barrier subjected to polarity‐reversed voltage pulses. The very fast polarity‐reversal with a rise time of 20 ns is caused by direct grounding of a charged coaxial cable 10 m in length. The influence of the voltage rise time on energy efficiency for NO removal is studied. The results of NO removal using a barrier‐type plasma reactor with a screw‐plane electrode system indicate that the energy efficiency of very fast polarity reversal caused by direct grounding is higher than that of slower polarity reversal caused by grounding through an inductor at the cable end. The energy efficiency of direct grounding is approximately 80 g/kWh for a 50% NO removal ratio and approximately 60 g/kWh for a 100% NO removal ratio. Very intense discharge light is observed at an initial time of 10 ns for fast polarity reversal, whereas the intensity of the initial discharge light for slower polarity reversal is relatively small. To confirm the effectiveness of the polarity‐reversed pulse application, a comparison of the energy efficiency of polarity‐reversed voltage pulses and an AC 60‐Hz voltage is presented. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 178(4): 32–38, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21215     

A study on condition assessment method of gas‐insulated switchgear. part II. influence of moisture in the SF6, detection of a partial discharge on a spacer,repetition discharge and overheating by incomplete contact

Rationalization of the maintenance of gas‐insulated equipment under operation and lifetime extension based on the results of appropriate diagnosis are necessary to reduce the cost of gas‐insulated equipment. Therefore, condition‐based maintenance (CBM) is required and accurate methods for observing the inside of equipment are important. In this report, we describe a diagnosis method that can be used for actual gas‐insulated equipment, such as to assess the deterioration of the spacers made of epoxy resin and to detect loose connections in the central conductor. The principal results are summarized as follows: (1) The quantity of decomposition gases depends on the moisture and magnitude of the partial discharge. However, decomposition gases were detected even if SF₆ had low moisture content (less than 100 ppm) similar to that used in actual equipment. This means that our method can be applied to actual equipment. (2) It became clear that CF₄ is a typical gas generated by partial discharge on the spacer surface. Therefore, it is possible to diagnose spacer deterioration by monitoring CF₄. (3) Decomposition gases (SF₄, SO₂, SO₄, SO₂F₂) were generated by impulse breakdown, which was assumed to be due to repetition discharge caused by insulation failure and loose connections. (4) SF₆ gas was assumed to be exposed to a loose connection and was heated from room temperature to 800 °C, and the generated decomposition gases were analyzed by FTIR in real time. As a result, the decomposition gases were generated at temperatures above approximately 500 °C in a heating time of 1.5 minutes. Therefore, a loose connection can be detected by analyzing the decomposition gas. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(2): 22–30, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21108