超超临界机组流动加速腐蚀的分析与控制

为研究流动加速腐蚀的机理、腐蚀产物的迁徙规律及找到抑制流动加速腐蚀的方法,根据寿光电厂1号机组汽水系统数据,对临界溶氧量、pH值、温度、压力以及加氧量的关系进行分析。结果表明:增大pH值与溶氧量,减小氢电导率,有利于抑制流动加速腐蚀的发生,其中pH值与溶氧量存在临界值;pH值、温度以及压力的增大均会导致临界溶氧量的增大;给水加氧是有效预防流动加速腐蚀的水处理方式。     

超临界机组流动加速腐蚀边界层流动模拟与分析

流动加速腐蚀(FAC)是电厂高压漏水、管道断裂等主要事故的原因,采用Fluent软件模拟管道的流动加速腐蚀规律,将微观与宏观研究联系起来,分析了温度、流速、管型与边界层流动及流动加速腐蚀之间的规律。结果表明:与其他温度相比,150℃时管道边界层处的Fe2+质量浓度增大,边界层的厚度更薄,边界层的腐蚀较严重,对流动加速腐蚀的影响也较大,为最易腐蚀温度;腐蚀速率随流速的增大而增大;T型三通管相比直管易发生腐蚀,且在流向改变处腐蚀最严重。     

流动加速腐蚀对电站3~#高加管束影响的综述及换热管材质对FAC影响的分析

分析了流动加速腐蚀(FAC)现象对火电厂3~#高加换热管束的影响,主要通过研究FAC的腐蚀机理及对火电厂实际运行后高加管束易发生泄漏位置的分析,最终确定管束中Cr含量高于1%时,可将FAC对管束的影响降到最低。     

流动加速腐蚀对碳钢管道的影响

流动加速腐蚀是电站内常见的一种腐蚀类型。由于影响流动加速腐蚀的因素较多,很难对流动加速腐蚀作出准确预测。对影响流动加速腐蚀的各种因素分别进行论述,并据此提出了理论计算公式。     

Cause Analysis on FAC Failures of Steam/Water Piping in Secondary Loop of PWR Power Plants and the Countermeasures

针对20世纪80年代以来国际上压水堆核电站二回路发生的因流动加速腐蚀引起的管道破裂事故造成的经济损失和社会影响,介绍了因流动加速腐蚀引起的事故及其造成的影响,进行了有关流动加速腐蚀特征、形成机理和影响因素方面的研究,并针对可以人为控制的因素提出了预防措施和对策,为压水堆核电站设计和运行人员提供因流动加速腐蚀对核安全造成的危害加以预防提供参考.     

微波强化光催化处理罗丹明B染料废水

采用微波无极灯强化光催化(MWL/TiO_2)对罗丹明B模拟废水进行处理。初步研究催化剂TiO_2的用量、罗丹明B初始浓度、微波功率、溶解氧、pH、反应温度、外加氧化剂H_2O_2量等因素对罗丹明B降解效果的影响。实验结果表明:最佳催化剂TiO_2的投加量为4g/L;较低pH、高溶解氧浓度、高微波功率、外加氧化剂H_2O_2有利于罗丹明B的降解。与常规光催化相比,微波减弱pH、染料初始浓度对降解效率的影响,同时增强温度对降解效率的影响。     

输油管道腐蚀因素分析与评价

针对输油管道普遍存在的腐蚀问题,选择某油厂作为研究对象,测试其地层水中各种离子含量和总矿化度,以及其它腐蚀因素。通过静态挂片实验,用失重法测试温度、含水率、矿化度、氯离子浓度、pH值、溶解氧以及硫酸盐还原菌对腐蚀速率的影响关系。结果表明,高矿化度、高氯离子含量、酸性环境是管道腐蚀的最直接因素;含水率越高腐蚀越严重;硫酸盐还原菌的存在会对管道产生严重的腐蚀。动态高压实验表明,真实的输油管道腐蚀速率要比静态测试的结果高得多,大约是它的3-5倍。油田现场的腐蚀是在各种腐蚀因素的综合作用下产生的,各种因素相互影响,相互促进,要比单一因素的破坏严重得多。     

响应面法优化蔗渣酶解工艺研究

利用Minitab软件对甘蔗渣酶解工艺条件进行优化研究。采用Plackett-Burman设计,从温度、pH值、加酶量、液固比和转速5个影响因素中,筛选出具有显著效应的温度、pH值和加酶量3个主要影响因素。然后采用响应面法对3个主要影响因素做进一步优化研究。优化结果表明:温度47.6℃,p H=4.76和加酶量37.76 Fpu/g时,综纤维素转化率可达74.5%。该条件下,实际试验值为74.44%,与预测值吻合较好。     

FPOT技术在660 MW超超临界机组中的应用

为解决锅炉给水全挥发处理(AVT)、给水加氧处理(OT)技术在实际应用中凸显的加热器流动加速腐蚀(FAC)、溶氧腐蚀和氧化皮生成及脱落问题,选取某660 MW超超临界机组为研究对象,通过试验验证了给水全保护自动加氧(FPOT)技术的可行性和有效性。对FPOT技术试验前后机组运行参数进行了分析对比,评估了FPOT技术的实际应用效果,进而提出FPOT运行及维护建议。试验结果表明:FPOT工况稳定运行后汽水系统含铁量大幅下降,高压加热器FAC问题有效缓解,精处理运行周期得到延长,炉内水汽系统形成了保护性双层钝化膜,实现了超超临界机组水化学工况的安全和稳定运行。     

低温环境下的流动加速腐蚀

流动加速腐蚀通常情况下发生在90~230℃之间,但在更低的温度下也会出现流动加速腐蚀,虽然不普遍,但是低温情况下的管道壁面材料损耗现象也可能会导致发电机组停机,从而需要花费大量的维护费用。首先介绍核电站常规岛发生低温流动加速腐蚀的损坏情况,证实在50℃的凝结水中会出现流动加速腐蚀导致的破坏。进而,对于如何预防以及监测低温流动加速腐蚀对管道的破坏提出建议。     

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.     

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。     

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。     

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.     

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。     

机车车轮多轴疲劳强度安全评定的研究

使用ANSYS8.0软件对高速列车车轮进行了三维有限元分析,计算出车轮在直线、曲线和道岔条件下牵引、制动共6种工况时孔边薄弱部位的应力,分别通过Mises等效平均应力方法、Sines平均主应力方法和应力分量中考虑平均应力方法计算出应力在极值位置时的等效应力幅、等效平均应力,从而进一步算出车轮的安全系数,对其疲劳强度进行评定,并对3种方法进行了比较研究。     

Constructal optimization of the geometry of an array of micro-channels

This paper documents the geometric optimization of an array of circular and non-circular ducts. The optimization was carried out numerically using finite volume method. As optimal dimensions were independent of the array configuration, the numerical simulation was performed on a unit cell. Numerical optimization for circular, square and isosceles right triangle cross-sections of channels was performed. Based on the results of this investigation, some correlations were proposed to predict the optimal hydraulic diameter and dimensionless heat transfer per unit volume. In addition to examining the effect of pressure drop on these parameters, it was showed that among the different geometries of this study, square cross-section has the most efficiency for a given volume. The numerical results of the present study were compared with approximate results reported in the literature which a good agreement was observed.     

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     

固体热辐射Yong性能分析

本文对漫灰均温物体在常物性条件下对外辐射传热的Ｙｏｎｇ值计算建立了数学模型。通过与物体内能Ｙｏｎｇ公式的数值计算比较,得出了辐射能量的Ｙｏｎｇ值不大于内能Ｙｏｎｇ值的结论。从初步的热射Ｙｏｎｇ值计算公式发现。Ｙｏｎｇ与物体表面辐射率有关。     

Measurements of concentration distribution of hydrogen jet using deflection of center of the laser spot

The main purpose of this work is to propose a new method to evaluate the concentration distribution of the hydrogen jet by using a He–Ne laser through the jet. This research attempts to apply the expression of concentration Gaussian distribution, the refraction formula of inhomogeneous refractive index medium, and the concentration inversion function to disclose the displacement of the center of the laser spot at different heights in the gas jet. The spot images of the laser beam passing through the gas jet at three vertical heights z = 10d, 20d, 30d, and different radial positions are obtained. The radial spatial asymmetry of the gas jet is also found in the experiment. Finally, the calculated concentration distribution curve and the fluent simulation curve, it is found that the two results are very similar. Our findings show that the error between the concentration distribution of this method and the simulated concentration distribution reaches 2.43%.