大型回转式空气预热器密封间隙调整方法

针对大唐国际神头第二发电厂3号、4号炉空气预热器整套装置是属回转三分仓式结构，同类型设备在国内外普遍存在漏风大的现象，既影响整台机组的经济性，又缩短了设备使用寿命，经过三个阶段的深入探讨和调整，将漏风率降至6％左右，使其达到最佳经济安全运行范围，具体调整方法可供同类型设备参考。     

管道泄漏计算机在线检测系统及其算法实现

设计了管道泄满计算机在线检测系统的总体结构，提出了一种基于工况分析的逻辑判决故障检测算法，当输油管道工作状况不断发生改变时，这种方法能够动态估计管道运行数据的正常值范围，很好地解决输油管道泄漏的故障检测问题，结合GPS技术和负压波定位算法，大大提高了报警准确性和定位精度，现场测试结果和实际工业应用证明了该方法的有效性。     

HL-2A装置真空室总体检漏

介绍中国环流器2号A偏滤器托卡马克装置真空室总装检漏及结果.根据其真空室特点设计了不同结构的检漏子系统,用氦质谱检漏仪、四极场质谱计与氦质谱检漏仪相结合的方法(双质谱法)分别进行零部件和真空室总体检漏,对有关检漏技术问题进行了讨论.     

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.     

液氮传导冷却型高温超导电流引线研制

80 A和200 A液氮传导冷却型高温超导(HTS)电流引线由铜引线段、中间过渡段和高温超导段组成,HTS热端采用液氮传导冷却,HTS冷端采用液氦传导冷却。铜引线段工作在室温到中间温度(~80 K),高温超导段工作温区6—80 K。介绍该传导冷却型电流引线的结构设计和低温性能测试。实验结果表明,中间过渡段温度~78 K,高温超导热端温度77 K;80 A、200 A电流引线液氦下稳态测试电流分别为100 A和250 A。     

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.     

托卡马克装置冷却管路钢铝混合接头真空钎焊工艺的研发

在对扬州恒星精密机械有限公司现有混合接头工艺分析的基础上,针对工程实践中存在的诸多问题,提出了托卡马克装置冷却管路钢铝混合接头真空钎焊工艺.该工艺在确定了抗拉强度、抗剪切强度、真空漏率等技术指标的基础上,采用Mg蒸汽保护进行真空焊接的同时缩小预置焊缝间隙,并通过改良钎焊料成分提高了焊缝韧性.     

高层建筑地下室防水渗漏问题探析

现阶段,我国社会经济的发展速度越来越快,建筑行业得到了极大的发展,在城市中诸多高层建筑不断出现。一般情况下,为了使高层建筑抗震、抗风和其他使用功能的要求得到满足,都会设置一层或多层地下室,而高层建筑地下室防水渗漏性能的好坏和高层建筑的功能效果以及使用寿命有着十分密切的联系。就此情况,本文结合工作实践经验,对高层建筑地下室的防水渗漏问题进行了探讨,并提出了相应的解决措施,以供参考。     

海管测漏技术在海洋平台的应用

总结管道泄漏监测和定位方法的工作原理及其优缺点。给出适用于海洋平台的测漏方法,同时列出测漏系统的关键技术参数,并重点分析负压波法和音波法方案比选结果及其在海洋平台的应用案例。     

A CO2 tracer-gas method for local air leakage detection and characterization

A method for local measurement of air leakage rate is presented that can be used to accurately and quickly assess leakage rates across a surface, such as around a valve or hatch in a pressurized gas tank or a window in a building. The method uses a small local enclosure with constant volume placed about a region on the structure under investigation (e.g., a window), which is depressurized and injected with a small concentration of carbon dioxide as a tracer gas. The time variation of the pressure and carbon dioxide concentration inside the enclosure are monitored and used to quantify the leakage flow rate as a function of pressure difference. This method uses a small enclosure with internal mixing so that a quasi-steady-state condition is quickly achieved. Because of the small size of the enclosure, advanced data processing techniques are necessary to reduce uncertainty in determination of the rate of change of the carbon dioxide concentration that arises from sensor variability. Results of a laboratory demonstration of the proposed leakage detection and characterization device are reported for the problem of leakage through a circular hole in a plate with prescribed pressure differences. Experimental results from the laboratory tests are found to be in excellent agreement with results of a numerical simulation of leakage flow through a hole, as well as predictions from a number of empirical equations for this problem found in the literature.