浅谈火电厂烟囱钛钢内简安装质量控制

近年来钛钢内筒因其具有突出的抗腐蚀性、耐高温及耐磨性在火电厂项目中得到越来越广泛的应用,而钢内筒安装是火电厂烟囱工程核心部分,对其质量控制显得很重要.本文结合茂名电厂钢内筒安装实例,详细介绍了钢内筒筒节组对、焊接、提升以及相关过程质量控制和注意事项,以确保安装质量达到预期效果.     

国内最大加氢反应器筒节锻造成功

近日，中国二重为中石化扬子石化公司生产的加氢反应器第一支筒节锻造成功。该筒节直径6250mm，是目前国内最大的容器筒节件。     

超长筒体与滚圈三维多体接触体系的力学特征

针对筒体、滚圈结构重复性强的特点，基于多重子结构技术，建立了超长筒体与滚圈三维多体接触模型；应用参数二次规划法，对中铝公司河南分公司2号窑筒体与滚圈的多体接触模型进行了有限元数值计算，得出结论：a从0°到360°，档位段筒壳的等效应力突变5次，筒节段筒壳的等效应力突变4次；b 档位段筒壳强度较弱，筒节段筒壳强度有一定富余；c2，3档位段筒壳是筒壳强度的薄弱环节。     

烟囱玻璃钢内筒正装法施工技术

本文主要阐述了烟囱玻璃钢内筒正装法施工技术,该技术采用履带吊将玻璃钢筒节由烟囱外部经烟囱顶口吊装入烟囱内部,在内部逐节安装完成,这对新建和改造烟囱玻璃钢内筒的安装施工具有很强的指导作用。     

萃取塔制造的塔体直线度控制

本文针对高塔制造出现的筒体直线度局部超标的现象,分析提出了在筒节制作、组对、焊接过程控制的办法。     

中国二重锻造成功首支AP1000核电锥形筒节

近日,中国第二重型机械集团公司(简称中国二重)成功锻制出首支AP1000第3代核电锥形筒节,标志着公司的核电生产技术又前进了一大步。第3代核电站较2代核电站的运行寿命延长20年,其压力容器关键锻件锥形筒节的技术要求更高。为保证制造出高质量的第3代核电锥形筒节,     

高塔中段筒节更换改造施工技术

利用临时支撑结构加固筒体上下部分 ,对中段筒节进行更换改造 ,具有施工简便、快速安全、经济效益显著的特点。     

第二急冷换热器筒体开裂原因分析

某石化公司乙烯厂乙烯装置的核心设备第二急冷换热器于2018年5月突然发生泄漏,导致设备停车.检修发现本次泄漏主要发生在换热器壳体靠近上管板的第一节筒节,壳体失效位置存在贯穿性裂纹,裂纹已沿厚度方向完全开裂.为此,查阅了该设备的原始制造资料,进行了换热器筒体开裂现象的应力分析、宏观检查和取样分析.最终确定碱应力腐蚀是引起换热器筒体失效开裂的根本原因,并提出了相应的防止措施.     

反向平衡法兰风电塔筒制作工法

工法是为了解决带反向平衡法兰的风电塔筒在制作过程中极易产生形变的问题。通过对带反向平衡法兰的风电塔筒制作工艺进行分析,设计了一种全新的塔筒组装焊接工艺流程,实现了反向平衡法兰与筒节组装焊接后不产生形变的目的,稳定了产品质量,为塔筒吊装创造有利条件,减少了反向平衡法兰塔筒在吊装过程中校正的工作量,从而提高了塔筒吊装效率。     

大型筒节热态锻件外径在线测量技术研究

提出了一种新的大型筒节热态锻件外径在线测量方法.该方法首先通过二维激光扫描仪扫描锻件表面的信息,将扫描仪到锻件表面的距离信息转化为坐标信息,然后进行数据拼接和曲线重构,显示锻件外形轮廓曲线,测量其尺寸信息,实现了大型筒节热态锻件外径的在线测量,并利用Matlab进行仿真,验证了该方法的可行性.     

镀铬枪管的基体初始烧蚀行为

为分析某型号机枪枪管的延寿机理，对4种不同工艺制备的镀铬枪管进行了寿命射击实验。通过解剖失效枪管，发现镀层下基体的初始烧蚀行为存在界面烧蚀、次界面烧蚀和穿透性烧蚀3种典型方式，枪管寿命相应由低到高。     

Hybrid Ceramic Matrix/Metal Matrix Composite Gun Barrels

Future Army gun systems will require lighter weight and significantly more erosion-resistant materials. One route to achieve this goal is via the development of ceramic matrix composite barrel liners with lightweight metal matrix composite jackets. Such materials systems are hybrids of a ceramic matrix composite/metal matrix composite (CMC/MMC), which can provide functionally graded properties. This paper will describe the materials system development, fabrication, and property validation testing of such a hybrid CMC/MMC for a 25-mm-bore, 915-mm-long, rifled barrel.     

枪管寿命模拟器和仿真

目的　研制一个系统 ,以便在枪管寿命的研究和预测中 ,显著地减少“画、加、打”循环 .方法　将模拟试验装置、建模与仿真及参数监测系统结合成一个闭环自修正系统 .结果与结论　通过 3～ 5发射击试验 ,真实、全面地再现了枪管在实弹射击条件下所经历的复杂的物理 -化学过程 ,同时 ,它能根据模拟试验的实测数据实时地修改模型 ,提高了枪管寿命仿真的真实性     

Spatially and temporally resolved single-cell exocytosis utilizing individually addressable carbon microelectrode arrays

We report the fabrication and characterization of carbon microelectrode arrays (MEAs) and their application to spatially and temporally resolve neurotransmitter release from single pheochromocytoma (PC12) cells. The carbon MEAs are composed of individually addressable 2.5-mum-radius microdisks embedded in glass. The fabrication involves pulling a multibarrel glass capillary containing a single carbon fiber in each barrel into a sharp tip, followed by beveling the electrode tip to form an array (10-20 microm) of carbon microdisks. This simple fabrication procedure eliminates the need for complicated wiring of the independent electrodes, thus allowing preparation of high-density individually addressable microelectrodes. The carbon MEAs have been characterized using scanning electron microscopy, steady-state and fast-scan voltammetry, and numerical simulations. Amperometric results show that subcellular heterogeneity in single-cell exocytosis can be electrochemically detected with MEAs. These ultrasmall electrochemical probes are suitable for detecting fast chemical events in tight spaces, as well as for developing multifunctional electrochemical microsensors.     

Electrolytic Co-deposition of Ni-CrAlY Composite Coatings Using Different Deposition Configurations

With the aim of seeking an alternative low-cost process for the fabrication of MCrAlY coatings, an electrolytic co-deposition process was employed to form a composite coating consisting of a Ni matrix and CrAlY particles. Three configurations were investigated in the co-deposition process, including a vertical setup, a horizontal arrangement, and a rotating barrel. The CrAlY volume fractions in the resultant composite coatings were compared. The advantages and disadvantages of each configuration were discussed. Among the three configurations studied in this paper, the rotating barrel demonstrated the best overall performance, with the capability of producing coatings with more uniform CrAlY particle incorporation of up to 40 vol.%.     

A laboratory demonstration electromagnetic launcher

A large laboratory demonstration electro-magnetic launcher is currently under construction. The design objective is to launch a 0.3 kg projectile at muzzle velocities up to 3 km/s in a 4 m barrel using a peak accelerating current of 1.5 MA. The primary energy source is a 15 MJ pulsed homopolar generator. Compression of its output pulse is achieved using a 5 MJ toroidal storage coil and a 1.5 MA opening switch. The design of all components was completed in the period April to October 1979, and the detailed design and fabrication is at present underway. Completion is anticipated in mid-1981. This paper outlines the design effort and present fabrication status.     

Fabrication of an aluminum, Caribbean-style, musical pan: Metallurgical and acoustical characterization

We report herein the first development and fabrication of a 6061 aluminum alloy pan and compare its tuning and acoustic spectra for selected notes with a standard low-carbon steel Caribbean pan fabricated from a 210-L barrel. The experimental aluminum alloy pan was completely manufactured by welding a 1.68-mm-thick head sheet to a 9-mm² aluminum alloy hoop, sinking the head by pneumatic hammering and welding a 1.15-mm-thick aluminum alloy side or skirt to the hoop. This experimental pan was 0.66 m in diameter, in contrast to the 210-L steel barrel standard, which had a diameter of 0.57 m. Chromatic tones were observed for most rim notes on the aluminum alloy pan, but the highest octave range notes at the pan bottom were not tuned. Microstructural characterization by light optical metallography and transmission electron microscopy illustrated the necessity for high dislocation densities and associated hardness in order to stabilize the notes and to assure their chromatic tuning.     

纤维增强复合材料身管阻尼特性分析

针对火炮发射时纤维增强复合材料身管的阻尼效应,根据粘弹性材料动态特性,给出了纤维增强复合材料能量耗散公式,采用基于有限元技术的模态应变能分析方法,对某口径复合材料身管进行了阻尼特性分析,获得了该复合材料身管在各阶固有频率下的应变能和阻尼损耗因子,为复合材料身管的动态特性分析提供了阻尼特性参数.     

测试装置重量对身管直线度测量精度影响分析

随着复合材料的广泛应用,复合材料身管直线度测量成为亟待解决的工艺难题,传统用于钢管直线度测量的装置将会引起较大的复合材料身管直线度测量误差,为此,应用ABAQUS有限元分析软件对处于不同载荷、不同支撑条件下的复合材料身管变形进行分析,建立复合材料身管三维有限元模型,分析得到不等重的测试装置在身管不同支撑条件下引起的复合材料身管变形量大小,设计相应试验验证有限元分析结果的正确性。结果表明测试装置自重及身管不同支撑条件对复合材料身管直线度测量精度产生重要影响,因此可以通过改变身管的支撑条件来降低测试装置自重的影响。采用数据拟合得到身管变形量和测试装置重量之间的关系,为复合材料身管直线度检测系统设计提供理论依据。     

A novel simulation approach for electromagnetic gun barrels

An approach to modeling a railgun barrel for performance simulations is discussed that is simple and readily implemented and yet is more representative of actual barrel performance due to electric/thermal effects. This novel, but simple, methodology differs from most of the dynamics equations. Instead, the barrel is discretized into small "cell" sections whose performance parameters vary linearly from one cell to the next. Each cell's electrical/thermal parameters that impact the barrel performance are updated and their effects on the barrel summed in entirety each iteration step; in effect, a distance iteration with a different time increment, which is a funtion of acceleratoin and velocity for each step. This technique allows variations due to materials, resistance, inductance and barrel topology. The simulation also permits a simplified pseudo-two-dimensional analysis to approximate a complicated temporal and spatial heat flow of a rapid-fire scenario. Even though this technique approximates a complex solution, the integrated system simulation executes quickly and has been operated on a personal computer (PC). The numerous advantages and flexibility of this simulation approach are discussed and correlated with other simulations and test data.