反动式汽轮机回热系统毕业翻译.doc

华中科技大学文华学院毕业设计论文华中科技大学文华学院毕业设计（论文）外文文献翻译（本科学生用）题 目：N600-16.67/537/537反动式汽轮机热力系统热平衡计算、7号高压加热器设计学 生 姓 名： 陈正 学 号：090204011101学 部(系)： 机 电 学 部 专 业 年 级： 09 级热能与动力工程 指 导 教 师： 刘 华 堂 职 称： 副 教 授 2011 年 4月 23日外文文献翻译（译成中文1000字左右）：【主要阅读文献不少于5篇，译文后附注文献信息，包括：作者、书名（或论文题目）、出 版 社（或刊物名称）、出版时间（或刊号）、页码。提供所译外文资料附件（印刷类含封面、封底、目录、翻译部分的复印件等，网站类的请附网址及原文】The receiver/detector and the prism are compact, lightweight devices mounted on the equipment shafts, with a cord-connected microcomputer module external to the receiver/detector. The prism, redirecting the infrared beam, allows measurement of parallel offset in one plane and angularity in the other, simultaneously checking both. One 360-deg rotation of the shafts is enough for determination of all four directional alignment corrections. The receiver is a biaxial, analog, photoelectric semiconductor position detector, giving mathematical results within a micron. Computation data enter automatically through the cable from the receiver/detector. The only manually entered datum is relative position-four times, at 0,90,180,and 270 deg, although results can be accurate even with only 180 deg rotation, in cases of physical obstruction. From the data automatically obtained from the receiver/detector, the microcomputer instantaneously gives the horizontal and vertical adjustment needed to align the MTBM Physical contact between measuring points is no longer required. The points are bridged by the laser beam, eliminating chance of error from gravitational hardware sag as well as from sticky dial indicators and human error in data taking. Quick-fastening brackets or other suitable hardware is the basic attachment method for the components.User acceptance A survey of US users of laser-optic devices indicates universal acceptance, with a single complaint. One user noted that the liquid-crystal-display alphanumerics fade in the low temperatures of a Midwestern winter. The user pointed out, nevertheless, that the computer had retained all input and calculated data and readily displayed the information when taken to a warmer location. The manufacturer has since corrected the problem. Laser-optic alignment at one plant takes only a fifth of the time previously spent on conventional reverse indicator alignment. In order of perceived importance, laser-optic alignment was superior for several reasons;Emitter-to-prism distance can be as close as 1 in, or as far as ft.Sag readings are unnecessaryDial-indicator misreading are impossibleCoupling can be in-place or removed.Detection of “soft-foot” conditions is easy and rapid.Thermal-growth target values are easily fed to the computer.The system is insensitive to axial float of shafts.Shaft rotation through only 180 deg will still give accurate results.Shaft-misalignment data feeds directly to the microprocessor, which displays instructions for vertical and horizontal alignment corrections of front and back feet.Misalignment condition at rim and face of coupling, or any other point along the shaft is displayed.Alignment of vertical pump/motor combinations is equally feasible.One-day training session is sufficient to teach all relevant aspects of use.System is lightweight, portable, and independent of external power sources.Difficult tasks In a massive alignment task at a Canadian powerplant, the setup of Fig 5 was one of four sets of laser-optic tool systems. Plant personnel, who took three repetitive data sequences in a seven-hour period, estimated that traditional dial-indicator measurements would have taken five times as long. The three data sequences allowed lay-out on paper of the existing alignment, so that conventional graphic plotting methods could give a manual check, even though the microcomputer displayed not only the “as-is” values but also the “moves to make” values.In the past, only one bearing would have been moved at a time before recheck of alignment. With laser-optics, workers made major shim changes simultaneously at nine bearing locations. After that, a second alignment reading gave two additional bearing corrections to fine-tune the five-day job which, on basis of experience, would have taken 11 days with the old methods.接收器、探测器和棱镜是结构紧凑、重量轻的设备,微型计算机组件由数据线连接到接收器/探测器。棱镜是接收红外线信号的部件,棱镜能够改变红外光束的方向，并测量一个平面上的两条光束的角度偏移。使用了一个能360度旋转轴保证能够接收的所有方向的信号。接收器是一个双向，模拟，半导体光电探测器,探测数据能精确到1微米。计算数据自动通过接收器/探测器输入数据线。只需要手动调准四个基准位置,分别在0、90,180及270度,甚至可以准确旋转180度,在有阻碍物的情况下,甚至可以准确旋转180度绕过阻碍物。接收器/探测器上获得的数据，输入微型计算机测量并立刻在水平和垂直方向进行调整，不再需要每隔一定时间进行调整。桥接的方式是使用激光器光束,消除了由重力和粘度造成的机械和人为误差，以及硬件错误的机会。快速固定支架或其它合适的硬件是最基本的固定部件。用户认可度我们对用户进行的一项调查显示,激光光学在各国普遍被接受,只接收到一个投诉。一个用户发现在中西部的冬天较低的温度下液晶显示器字母与数字会消失。用户指出，尽管如此，该设备可以保留了所有计算机输入和计算的数据，当把设备带到温暖的位置时很容易显示保留的信息。制造商已经纠正了这个问题。激光光学设备校准要需要花费以往的传统方式所花的时间的五分之一。因为这些原因，在人们心中，激光光学设备的重要性更加靠前：发射器到棱镜距离可以接近1,最大不超过7英尺。不需要估读数据显示器示数不会被误读可以在任何地方连接或移动检测的条件是简单和迅速。热量增长值是很容易输入到计算机。系统对轴向的波动不敏感。轴通仅180度的旋转过仍将给您提供精确的结果。激光束未对准时的数据输入微型计算机，会直接显示所指示水平和垂直修正前后的数据。没对准位置在边缘和表面或任何其他点激光束都能显示出来。对齐垂直泵/电机的排列组合也同样是可行的。一天的训练就足以学习所有有关方面的使用方式。设备很轻,便于携带的，还有独立于外部的电源。困难的任务在加拿大的一件巨大的发动机在大规模