带压堵漏技术的研究现状及应用

介绍了带压堵漏技术工作原理与特点,概述了该技术的研究现状与发展,带压堵漏由夹具、密封剂、专用注剂工具和操作方法 4部分内容组成。其中,密封剂和夹具是这项技术的关键技术环节,密封剂性能应满足耐介质性、耐热性、适宜的固化时间、密封空间内残余收缩量要小,最好能不收缩等要求。结合带压堵漏技术在某炼油厂的实际应用,证明了价值所在,指出了带压堵漏包括对有关人员专门的培训、制定详尽的安全施工措施、配戴安全防护用品和在高空作业架设带防护栏的防滑平台等安全注意事项。带压堵漏技术还不够完善,有待进一步研究和提高,提出了一些可操作性的建议。     

换热器管束风险计算方法的修正

主要针对RBI风险运算过程中换热器管束存在的问题,首先,讨论了常用的失效可能性计算法方法,并根据极限状态方程的特点及RBI计算的需要,认为采用一次二阶矩方法比较适合RBI的失效后果计算;其次,通过分析RBI中风险后果的计算模型,指出换热器管束风险计算普遍偏高的原因,并根据风险偏高的原因,对换热器管束的风险计算进行了修正;最后,通过一个算例,对比修正前、后换热器管束的风险结果,发现修正后的风险比传统方法降低了一个数量级。     

基于交换系统的CDR话单准确性稽核模型研究

收入保障系统的建设已经成为国际电信业运营管理的一个目标和方向.本文基于交换机成对下单原理,结合国内电信企业的实际情况,提出了一种适合国内电信运营及支撑现状的基于交换系统的CDR话单准确性稽核模型.湖南某大型电信企业基于该稽核模型进行了工程实施试点,结果表明:本文提出的稽核模型具有良好的可操作性,能有效地发现交换机CDR话单生成过程中所存在的收入漏洞.     

炉台紧急吹扫故障判断方法

通过对炉台设备的简介及紧急吹扫的统计分析,提出了判断紧急吹扫故障的合理方法,提高了故障的准确判断率,减少了对生产的影响。     

常压储罐底板检漏仪的设计及其空气运动学数值模拟

针对大型立式圆筒形储罐底板设计特点,论述了底板检漏仪器设计及结构的确定,以及空气流场在检漏仪内部的数值模拟,确立了检漏仪的有效检测范围、压力梯度,涡流的形成及风的形成情况,提出优化检漏仪的设想。考虑到圆筒形常压储罐的检测级别,已经可以满足基本的检验要求,故可以大范围的推广使用。     

85 m3液氢铁路槽车的检漏和抽空

介绍了85 m3液氢铁路槽车首次定期检修过程中检漏与抽真空的设备配置、系统组成和实施工艺,对槽车夹层气体进行了质谱分析,对检漏工艺和抽空工艺的实施经验进行了分析.结果表明:氢气、水气和氮气是夹层的主要气体成分,首先进行检漏可为后面抽空提供前提条件,热氮冲洗置换和间断抽空排气的抽空工艺可以大大缩短抽空时间,得出了抽空时间与漏放气速率变化的规律.     

Development of Acoustic Leak Detection and Localization Methods for Inlet Piping of Fugen Nuclear Power Plant

The development work carried out on Fugen NPP is focused on detection of a small leakage on the reactor's inlet feeder pipes at an early stage by an acoustic leak detection method with usage of high-temperature resistant microphones. Specifically, the leak rate of 0.046 m³/h has been chosen as a target detection capability for this system. A cross-correlation technique has been studied for leak detection under low signal-noise ratios. The study shows that the sound diffusion on piping causes distortion of leak signals that results in their low correlation. A leak-location estimator and multi-channel correlation value, associated with estimated leak position, have been employed to detect such low-correlated leak signals. A method based on cross-correlation of signal spectral components has been proposed to deal with non-stationary leak signals. Joint-Time-Frequency-Analysis has been applied to analyze such signals, whilst a Wavelet decomposition technique has been used to extract their short-term spectral fluctuations. Since the spectral components are less affected by signal distortion, they provide higher correlation value and can be applied for leak detection under lower signal-noise ratios. The possibility of detecting and locating a small leakage by the methods proposed has been demonstrated by a number of simulation tests conducted on the Fugen NPP site.     

On-Line Leak Detection Method for OWL-1 Loop by ARX Modeling Using Dewpoint Signals

Model identification technique based on ARX (autoregressive model with exogenous variable) process was applied to dewpoint data recorded at OWL-1 (Oarai Water Loop No. 1) loop cubicle in JMTR (Japan Materials Testing Reactor) and the dynamical interrelationship between the supply and exhaust dewpoints in the ventilation system of the cubicle was empirically determined.

It was shown that the information so derived on the dewpoint dynamics can assist to enhance the sensitivity of leak detection, if it was incorporated into a leak monitoring system for the OWL-1 loop.

A simple digital filter incorporating the dewpoint dynamics was designed in an attempt to develop an efficient leak monitor for the OWL-1 loop. This filter was applied to the dewpoint data recordings during an abnormal leak that had occurred at the OWL-1 loop in the 43 rd cycle of JMTR operation, which demonstrated the effectiveness of the present method for leak detection at its early stage.     

天然气管道泄漏声场特性研究

根据莱特希尔理论可确定天然气管道泄漏处声源为四极子声源,用声强方程和莱特希尔气动力声方程,推导出天然气管道泄漏喷流噪声强度与喷流速度间的关系式。用Matlab软件对天然气管道泄漏声场进行数值模拟,分析了天然气管道泄漏时的声场分布及声压级。结果表明,管道内声波形成驻波且整体声压都很大,管道外为四极子声源所产生的声场,声波的辐射和衰减较快;随着泄漏孔直径D和管内运行压力p0的增大,声场声压p和声压级SPL也增大。该项研究为天然气管道泄漏的进一步研究提供了理论基础。     

半流体润滑脂在抽油机减速箱保养中的应用

抽油机减速箱的润滑和漏失问题已经严重影响了抽油机的正常运转，引起了人们的重视。为了解决这个问题，中原油田分公司采油一厂应用了由燕化集团生产的半流体润滑脂，先后应用于20台抽油机减速箱的润滑保养，通过6个月应用与监测，发现该半流体脂的润滑及防漏效果良好。