1000 MW超超临界锅炉水冷壁高温腐蚀防护及涂层方案选择

针对某电厂的超超临界1 000 MW机组锅炉可能产生高温腐蚀问题,展开锅炉水冷壁高温腐蚀防护试验研究。锅炉受热面高硫条件下,筛选出防护高温腐蚀、冲蚀磨损性能优良的涂层,优化制备工艺,对涂层性能和使用寿命进行综合评价和预测。结果表明,采用超音速火焰NiCr金属陶瓷涂层、超音速电弧45CT涂层和M650涂层对该电厂1 000 MW机组锅炉受热面的高温腐蚀防护具有经济适用性。     

超临界锅炉管道耐磨涂层的微观组织结构及冲蚀规律

开发两种适用于超临界锅炉管道防磨的含TiAl3(AW1)、Cr3C2(AW2)的复合粉芯丝材,采用超音速电弧喷涂技术制取耐磨涂层,结合光学显微镜、维氏硬度、X射线衍射、场发射扫描电子显微镜、能谱分析等分析方法对喷涂层的的微观组织结构和高温冲蚀磨损规律进行研究,并与20钢进行对比分析。结果表明:AW1、AW2涂层具有固溶体相和氧化物相相互间隔的叠层结构特点;经800°C1、50 h氧化试验,AW1和AW2涂层的抗氧化性能分别是20钢的10倍和15倍;20钢、AW1和AW2涂层的最大冲蚀率分别出现在15°和45°冲蚀角附近;AW1涂层具有与商用AW2涂层接近的耐高温冲蚀性能,耐冲蚀性能明显优于20钢;当冲蚀角为45°时,AW1和AW2涂层的耐冲蚀性分别是20钢的3.1和3.0倍。图7表2参6     

含CO_2气流对20号碳钢冲蚀磨损性能影响的试验研究

火电站燃煤锅炉由于飞灰冲蚀磨损而导致爆管的问题一直是行业急待解决的问题。用试验研究方法,在温度为250-450℃之间,研究了气流中含CO2气体时对20号碳钢冲蚀磨损性能的影响,并与之前在压缩空气流中做的此类试验结果做了比较。试验结果表明,加入CO2气流后20号碳钢的磨损规律未变,其相对磨损量随温度的升高先减小后增大。同时,由于氧化腐蚀和冲蚀的交互作用,加入CO2气流后20号碳钢的冲蚀磨损量明显增大。     

含SO_2气流对20号碳钢冲蚀磨损性能影响的试验研究

主要研究燃煤锅炉中烟气中含有SO_2腐蚀性气体对锅炉尾部烟道常用金属材料20号碳钢冲蚀磨损的影响。在试验台上进行了250~450℃温度范围内,含SO_2的气流对20号碳钢的热态飞灰冲蚀磨损试验研究。试验结果表明:20号碳钢在含SO_2腐蚀性气体中的相对冲蚀磨损量明显大于之前在压缩空气流中的相对冲蚀磨损量,显然由于磨损和腐蚀交互进行,使得金属冲蚀磨损加剧。并且在试验温度范围内低温段的影响大于高温段的影响。20号碳钢的热态磨损特性不变,仍然是随温度升高,磨损率先下降而后升高,而临界温度有所提高,为375℃。     

锅炉水冷壁爆管事故的分析

针对一起锅炉水冷壁爆管事故,从水冷壁的受热状态、水循环、管壁应力等方面进行了分析,指出局部水冷壁受热强,水循环流速缓慢,导致水冷壁金属超温过热;管内壁的汽水腐蚀、管外壁的高温氧化,再加上高速烟气气流对向火侧管壁金属的剧烈磨损,导致管壁金属发生严重减薄,承受的应力水平进一步提高;频繁的启、停锅炉以及压力波动、温度变化,导致水冷壁上部弯管部位金属既承受弯曲应力,又同时承受着较大的交变应力作用。由此得出造成局部水冷壁金属超温过热、高温腐蚀、磨损减薄以及交变压力等是导致爆管的主要原因。     

电站锅炉管道高温冲蚀磨损和涂层防护技术分析

在锅炉的实际运行过程中,由于高温环境,锅炉会出现冲蚀磨损问题,其安全性也就会随之下降,这就需要通过涂层防护技术来加以保护。本文就是对其管道高温冲蚀磨损问题和涂层防护技术进行分析,希望可以对当今电站锅炉的正常应用提供出更好的依据。     

循环流化床锅炉中水冷壁的磨损原理及其预防

循环流化床锅炉水冷壁管的磨损是影响循环流化床锅炉运行的一个主要因素.总结了循环流化床锅炉中水冷壁管的磨损情况,根据其磨损机理分析了预防磨损的措施.磨损的根本原因是气固两相流场造成的,因此改善易磨损部位的流场可以减轻磨损.采用厚壁水冷壁管、降低流化速度,也可以有效防止磨损爆管.运行经验表明,这些措施能大大地改善磨损情况,延长水冷壁管的使用寿命.     

20碳钢在腐蚀性气流环境中飞灰冲蚀磨损试验研究

利用热态飞灰磨损试验台,向试验气流中加入一定量的SO2和CO2气体,在250~500℃内进行电厂20碳钢金属材料的耐冲蚀磨损性能试验,研究SO2和CO2气体对金属冲蚀磨损性能的影响,并对不同气流环境下的试验结果进行比较.结果表明:随着温度的升高,20碳钢在试验温度范围内均出现相对磨损量先减小后增大的现象;20碳钢在加入SO2或CO2气流环境下的相对磨损量明显高于只含压缩空气环境下的相对磨损量,可见电站锅炉烟气流中CO2和SO2气体能够加速20碳钢的冲蚀磨损.     

CO_2气流对几种钢材的飞灰冲蚀磨损的试验研究

参照燃煤电厂锅炉烟气中CO_2气体的含量比例,在试验气流中加入一定量的CO_2气体,利用热态飞灰磨损试验台进行温度在250~500℃范围内电厂常用金属材料20碳钢、12Cr1Mo V合金钢及15CrMo合金钢的耐冲蚀磨损性能的试验研究。试验结果表明:在试验温度范围内3种材料的相对磨损量保持了随温度的升高先减小后增大的热态磨损特性。同时,加入CO_2气流后3种金属材料的冲蚀磨损量均明显大于只含压缩空气环境下的相对磨损量,CO_2气体会加速金属的冲蚀磨损;其中12Cr1Mo V耐磨性能好于15CrMo,15CrMo耐磨性能好于20碳钢。     

超音速电弧喷涂镍铬合金在锅炉水冷壁中的防磨应用

锅炉水冷壁管高温腐蚀和磨损的机理复杂,对其表面覆盖耐磨耐腐蚀的隔离层,是最直接有效的防磨措施.介绍了火焰喷涂与超音速电弧喷涂两种工艺及其在不同锅炉膜式水冷壁上的使用情况,通过应用对比,认为超音速电弧喷涂镍铬合金能够对锅炉水冷壁的保护提供一个非常可靠的解决办法.     

Unerroric of control of mutual compliance of the efficiency of hydrogen engines of unmanned vehicles in the conditions of mass production

The issues related to the reliability of hydrogen engines of unmanned vehicles and increasing the efficiency of using hydrogen as fuel when using the method of its production during the decomposition of hydrogen-containing molecules of liquid-phase organic compounds in a plasma discharge under the action of intense ultrasonic exposure are considered. Experiments have shown that as a result of decomposition in the acoustoplasma discharge of liquid hydrocarbons, solid-phase carbon-containing products are formed, chemical transformations occur in the liquid phase and hydrogen-containing combustible gas is formed. Hydrogen-containing gas can be used as fuel immediately after synthesis, i.e. it does not require separation, since in addition to hydrogen it contains only impurities of CO₂ and water vapor. The purpose of the study is to formalize the basic conditions for tightening the control of mutual compliance with the efficiency of hydrogen engines of the same series in the conditions of their mass production. Methods of mathematical statistics and hardware-software modeling were used in the study. The term “unerroric of quality mutual compliance control” is introduced to describe a set of hardware and software tools for such control. The principle of in-depth testing of the technical condition of such engines of one series is described in a multidimensional formulation of the quality control problem for three of their operating parameters at once. The conditions for increasing the mutual correspondence of the measured values of such parameters in the conditions of serial production of hydrogen engines are formalized.     

MgO膨胀剂细度对MgO水化和水泥浆体膨胀的影响

基于《水工混凝土掺用氧化镁技术规范》中的Ⅰ型氧化镁（MgO）,研究了该型MgO膨胀剂（MEA）细度对掺粉煤灰水泥浆体膨胀性能的影响。即采用X射线衍射分析(XRD)及同步热分析（TG DSC）分析了掺MEA水泥浆体中MgO的水化性。结果表明,养护温度相同时,MEA的细度对水泥浆体内MEA中MgO的水化和水泥浆体的膨胀无显著影响,产生的膨胀均能补偿水泥浆体的收缩;MEA的细度可从试验设计采用的45 μm筛筛余15%左右增加到30%左右,这将有利于MEA生产企业的节能降耗。     

小型锅炉烟尘测试时锅炉出力的计算

锅炉烟尘测试时,必须对锅炉出力进行测试。但监测中,许多小型锅炉往往不具备相关的计量装置和仪表,为解决这一问题,文章提出了用烟气量和空气过剩系数来计算锅炉的出力的公式,在实际使用中,该方法简单易行,其结果和实测值具有很好的一致怀。     

Heat of vaporization of mixtures

General expressions for the heat of vaporization of mixtures at constant pressure; at constant temperature; and at constant pressure, temperature, and composition are proposed. The last one is related to the liquid-vapor interface where steady vaporization or condensation is taking place. Numerical examples by the proposed expressions are shown for binary mixtures of HCFC22(R22) and (HCFC123(R123) © 1997 Scripta Technica, Inc. Heat Trans Jpn Res, 25(1): 12–24, 1996     

生物质催化热裂解技术的研究进展

生物质催化裂解是生物质热化学转化的一种重要途径。综述了生物质催化热裂解技术使用的反应器、催化剂类型,以及催化热裂解过程中热裂解温度、吹扫气、升温速率、生物质原料等条件的影响,展望了生物质催化热裂解技术的发展趋势。     

燃烧流化床气泡能量分布模型

应用瞬态谱分析方法对燃烧流化床声波信号进行了频谱分析,发现气泡能量分布呈Ｇａｍｍａ分布形式,在Ａｒｇｙｒｉｏｕｓ和Ｙｏｓｈｉｄａ等人提出的模型的基础上,发展了燃烧流化床气泡能量分布模型,并通过优化迭代对模型参数进行求解,在实验和理论的基础上得出了更加切合实际的燃烧流化床气泡能量分布模型     

促进城镇生活污水处理装置产业化

城镇生活污水处理装置是由农村户用沼气地发展演变而来，是一种小型、分散化处理污水的装置 ，是环境建设的需要。文章着重从我国环保政策及目标、生活污水造成的污染状况、急需整治的公共设施、生活污水净化装置的演变以及社会经济效益和环境效益等方面，阐述了其产业化的重要性。     

中国煤炭地下气化技术的发展

本文综述了煤炭地下汽化技术的国内外发展现状,对我国“长通道、大断面”煤炭地下气化新工艺给予了技术经济评述,并提出了发展煤炭地下汽化技术的政策建议。     

Investigation of effect of variation of cycle parameters on thermodynamic performance of gas-steam combined cycle

The paper deals with second law thermodynamic analysis of a basic gas turbine based gas-steam combined cycle. The article investigates the effect of variation of cycle parameters on rational efficiency and component-wise non-dimensionalised exergy destruction of the plant. Component-wise inefficiencies of the combined cycle have been quantified with the objective to pin-point the major sources of exergy destruction. The parameter that affects cycle performance most is the TIT (turbine inlet temperature). TIT should be kept on the higher side, because at lower values, the exergy destruction is higher. The summation of total exergy destruction of all components in percentage terms is lower (44.88%) at TIT of 1800 K & r_p,c = 23, as compared to that at TIT = 1700 K. The sum total of rational efficiency of gas turbine and steam turbine is found to be higher (54.91%) at TIT = 1800 K & r_p,c = 23, as compared to that at TIT = 1700 K. Compressor pressure ratio also affects the exergy performance. The sum total of exergy destruction of all components of the combined cycle plant is lower (44.17%) at higher value of compressor pressure ratio (23)& TIT = 1700 K, as compared to that at compressor pressure ratio (16). Also exergy destruction is minimized with the adoption of multi-pressure-reheat steam generator configuration.     

Review of theory of distortion and disintegration of liquid streams

Linear and nonlinear analyses of the instabilities and distortion of liquid streams injected into a gaseous media are discussed. The various fundamental mechanisms and the predictive capabilities for the distortions are emphasized. Round jets, planar sheets, annular sheets, and conical sheets are discussed in detail. The balance between capillary and inertial forces is primarily examined. The method for simplifying the analyses in the case of thin liquid sheets is discussed. The capabilities for representing the droplet size distribution that follows the stream disintegration are outlined.