基于Labview的火电厂锅炉四管泄漏声测系统

介绍了一种基于虚拟仪器的火电厂锅炉四管泄漏数字化声学检测系统。它利用National Instrument公司的软件平台Labview和硬件平台实现声信号的实时采集、分析和处理，达到快速准确判断四管泄漏与否的目的。该系统在现场应用中取得了良好的效果。     

Silicon surface treatment via CVD of inner steel tube surfaces

Inner surfaces of steel tubes should be protected against corrosion and oxidation by a coating in order to assure optimised application in power plants and the chemical industry. Since the silicon content in chromium alloyed steels improves the oxidation protection. Chemical vapour deposition (CVD) of Si has been investigated for martensitic 9% chromium steel (T91). The surface treatment was performed as a combined process of CVD at atmospheric pressure with heat treatment in a chemical atmosphere with high frequency heating (HF), automated with a Simatic PCS7. The Si out of SiCI₄ diffused into the steel lattice of the substrate surface. As a result, the Si‐content near the surface layer increased as a ferrite layer which did not transform to martensite during heat treatment. The excess of Si was converted to Si₃N₄ using NH₃. This improves the anti‐oxidation behaviour. The physical and chemical properties of the modified surfaces were investigated and characterised using the SEM, EDX, electron microprobe and X‐ray diffraction methods. The deformation capacity of a coated specimen was proven by means of hot tensile tests. It could be determined that in the ferritic layer Fe is substituted by Si with a maximum concentration of approx. 5%, however the Cr content was almost constant.     

五次Ginzburg—Landau方程行波解的不稳定性

研究了五次Ｇｉｎｚｂｕｒｇ－Ｌａｎｄａｕ方程行波解的存在性及不稳定的色散关系，讨论了行波解的性质，得到了行波解及Ｓｔｏｋｅｓ解的振荡性，稳定性及不稳定性的色散关系表达式。     

凝汽器铜管FeSO4成膜表面预处理方法试验研究

凝汽器铜管硫酸亚铁成膜前铜管表面的预处理是保证成膜质量的重要前提，但也是最容易被忽视的地方。作者选择各种不同材质及不同表面状况的铜管作为研究对象，并采用多种没方法进行表面预处理，然后在同一条件下成膜，并用民位扫描法进行检验。结果表明旧铜管必须首先酸洗除去表面污垢，再通过碱洗和水冲洗使表面产生一层ＣｕＯ２膜才能成膜；而新铜管可不经过酸洗，只要除去油污就可直接成膜。     

焊接方形钢管桁架结构设计

对国内外方管、矩形管结构的应用研究现状作了分析，总结了方管、矩彩管桥架焊接节点的受力、破坏特点，介绍了国际上推荐的方管节点设计计算公式，指出了这种结构设计时应注意的问题，并以实例介绍了这种结构的设计过程。     

钛合金管材二辊矫直机辊型曲线与矫直精度分析

针对钛合金管材很难被矫直的问题,采用压扁加反弯的方法得到很好的矫直效果。设计了实现钛合金管材压扁加反弯矫直的分段等曲率反弯辊型,从弹塑性基本理论出发,推导了矫直过程中考虑材料强化条件下的弯矩公式,并建立了矫直精度的理论计算模型。借助该矫直精度计算模型对反弯量组合进行了优化,针对典型产品的分段等曲率反弯钛合金管材,提出合理的压扁量取值范围,为实际生产中辊缝调节提供参考。     

Preparation of separated and open end TiO2 nanotubes

Separated and open end TiO₂ nanotubes with large surface area and through-hole structure exhibit exciting functionalities in energy and environmental applications. In this study, TiO₂ nanotube membranes are created using high purity titanium sheets as raw materials by anodic oxidation at 100 V for 12 h in ethylene glycol+0.25 wt% NH₄F+5 vol% H₂O. The pore size of the nanotubes is 215 nm with uniform diameters. Close-packed TiO₂ nanotube arrays are separated by immersion in a 0.15 wt% HF water solution. With further dissolution by 40% HF water solution for 10 min, the barrier layer at the back of the TiO₂ nanotubes completely disappears and the nanotubes become open at both ends. This study offers a facile approach of making separated and open-end nanotubes for electrocatalytic purposes.     

扭曲椭圆管换热器的数值模拟及场协同分析

为了分析换热管几何参数对扭曲椭圆管换热器管程和壳程的传热与压降性能以及场协同关系的影响,今运用Fluent 6.3.26对不同几何参数的扭曲椭圆管换热器的管内和管外对流传热进行了数值模拟,并编写UDF程序计算温度场与速度场的夹角,即场协同角。结果表明:Realizable k-ε模型相对更好地模拟出扭曲椭圆管换热器管内和管外的流场和温度场,努赛尔数Nu以及摩擦系数f与实验结果的差别都在5%以内。在扭曲椭圆管换热器的管程和壳程,Nu和f都随着扭曲椭圆管长短轴比的增大而增大,随着扭矩的减小而增大。基于场协同理论分析,协同角随Re的变化不大,但不同几何参数的扭曲椭圆管管内和管外的协同角都存在差异,二次流的出现优化了速度场以及温度场分布,减小了速度场以及温度梯度场之间的夹角,实现强化传热。     

等离子喷涂工艺对锅炉管束用Fe 基非晶涂层组织结构和耐蚀性能的影响

目的研究等离子喷涂功率和喷涂时间对锅炉管束用Fe基非晶涂层的相组成、微观组织结构及涂层耐蚀性能的影响。方法通过X射线衍射、扫描电子显微镜和三电极电化学研究进行分析。结果涂层主要由非晶相组成,表面较为平整致密;随着喷涂功率和喷涂时间的增加,涂层非晶相含量降低,孔隙率降低,致密性升高。非晶涂层在0.5mol/L H2SO4溶液和在3.5%(质量分数)NaCl溶液中均表现出良好的钝化作用,在0.5mol/L H2SO4溶液中钝化区较宽,在3.5%NaCl溶液中自腐蚀电流密度较低。随喷涂功率和时间的增加,阳极极化曲线钝化区加宽,电流密度降低。结论喷涂功率升高会导致涂层孔隙率下降,喷涂时间增加则致使涂层厚度增加,腐蚀介质渗透到基体的表面路径和阻力增加,从而可以进一步改善Fe基非晶涂层的耐蚀性能。     

GFRP管钢筋混凝土偏压长柱的试验研究

通过15个GFRP管钢筋混凝土长柱和1个无GFRP管约束的钢筋混凝土柱在偏心受压作用下的试验,研究了其破坏形态及力学性能,并分析了混凝土强度、长径比、偏心距等因素对柱力学性能的影响.试验结果表明,GFRP管的约束作用能有效提高柱的承载力及延性;随着混凝土强度的提高,GFRP管钢筋混凝土柱的承载力和刚度增大;随长径比和偏心距的增大,GFRP管对混凝土的约束效果降低,柱的承载力降低;平截面假定适用于GFRP管钢筋混凝土偏压长柱的计算.