水轮发电机定子绕组端头的绝缘浇灌

大型水轮发电机定子绕组端头的连接转弯处并头焊上后要进行绝缘处理,常规的方法是套上绝缘盒,盒内浇灌环氧胶。制造厂浇灌通常是把分瓣定子竖起来用行车挂在厂房内,然后在下部的端头并头处套上绝缘盒并设法定位固定,再向盒内倒入环氧胶。另一端则是将分瓣定子翻身,再同样进行     

浅谈水轮发电机组定子端部绝缘盒流胶、开裂缺陷及处理

以国内某大型水电站水轮发电机组定子端部出现绝缘盒流胶、开裂缺陷为出发点,对可能产生定子端部绝缘盒流胶、开裂缺陷的原因进行了分析,并提出了处理方法。     

发电机定子绝缘盒内绝缘材料常见问题解析

定子绝缘盒是发电机绝缘的关键部件,其绝缘性能的好坏直接影响到机组及电网运行的安全.通过运用所积累的长期安装及运行经验,对水轮发电机组定子绕组绝缘盒内绝缘材料常见问题,如气泡、变色、开裂等进行梳理,分析了上述劣化现象产生的原因,并提出相应设计、施工、运行中的改进措施.可为水轮发电机组定子绕组绝缘盒内绝缘材料配制、灌注方法及定子下线工艺改进提供维护工作参考.     

150MW水轮发电机定子端部绝缘泄漏处理

介绍棉花滩水电厂3号水轮发电机（150 MW）定子端部绝缘盒缺陷的处理情况,分析缺陷产生原因,总结出一套缺陷处理的工序及工艺,为大型水轮发电机定子端部绝缘缺陷处理积累了实践经验。     

华能太平驿电站定子线棒端部绝缘灌注胶固化缺陷分析

华能太平驿电站机组技改项目中,1号机组定子现场组装阶段定子线棒干燥时,发现部分线棒端部绝缘灌注胶固化不完全。经过对绝缘灌注胶的灌注过程、配比进行分析,得出结论因搅拌不均导致绝缘盒内的灌注胶成分基本是环氧树脂,有固化剂成分,但很少,最终导致绝缘灌注胶固化不完全。本文对水轮发电机定子线棒绝缘灌注胶的固化工艺进行了分析[1],为水电站发电机定子现场组装时绝缘胶固化提供一定参考。     

白山水电厂水轮发电机绝缘降低原因及处理方法

运用溢出电位法准确地判明定子端头盒绝缘缺陷,找出水轮发电机定、转子绕组绝缘击穿和下降的原因,并提出了有效的处理方法。     

耐压试验在定子绝缘击穿事故中的应用

1概述发电机是发电厂最重要的设备,其中对于定子绕组的绝缘保护更应十分重视,因此单机容量800 kW以上的发电机均要求装设纵联差动保护,作为定子绕组的主保护。对于发电机绝缘性能的试验,可以分为绝缘特性试验和绝缘强度试验,其中绝缘强度试验有可能导致绝缘的破坏,故亦成为破坏性试验。发电机绝缘强度试验主要有工频交流耐压试验和直流耐压试验两种,两者各有特点：交流耐压试验便于发现电机槽部及槽口处的绝缘缺陷,直流耐压试验便于发现电机端部的绝缘缺陷。     

水轮发电机定子线圈处理后电位外移试验必要性

电位外移试验是一项比较新的试验项目,电力行业标准《电力设备预防性试验规程》(DL/T 596—1996)中增加了"定子绕组端部绝缘施加直流电压测量"一项,规定了200 MW及以上国产水氢氢汽轮发电机在1.0 U_n直流试验电压下的标准,但对水轮发电机没有做要求。然而大型水轮发电机定子大修或者线棒处理后,相比于新机组,定子绕组可能存在少数线棒因焊接、现场绝缘包扎等较多因数引起线棒端部绝缘缺陷,而该缺陷用一般的交直流耐压试验无法很好的检测出来。以三板溪电厂2、3号机定子处理为例,通过对试验数据与现场情况的研究,来探讨大型水轮发电机定子绕组处理后其端部局部泄漏试验的必要性和相关的结果利用。图3幅,表3个。     

氢冷发电机定子绕组电气绝缘试验

以杭州华电半山发电有限公司2004年投产的390H氢冷发电机为例,通过比较GE公司的电气试验说明和国内标准,根据其定子绕组绝缘材料和工艺,分析了中外标准差异的原因,从而确定相应氢冷发电机定子绕组（环氧粉云母绝缘）的电气试验,更好地完成电气绝缘监督工作。     

深溪沟水电站发电机通风系统改造

深溪沟水电站运行中发现下机架基坑环境温度及发电机上下端部绝缘盒运行温度均偏高。通过机组检修,调节上下两个支路风量的分配比例,并通过增设挡风板等措施优化局部的通风结构和减少漏风,基本达到了降低定子上下端部绝缘盒的运行温度,并改善风罩内下机架位置的环境温度的目的,消除了设备运行的不安全因素。     

2003年兰考、东明洪水漫滩落淤情况调查

通过对2003年秋汛期间兰考北滩、东明南滩两处漫滩情况进行调查与分析，得出的结论为：滩区共滞蓄水量6亿～9亿m^3，漫滩落淤范围为7．5km^2，顺漫滩水流方向的落淤距离约3km。在这种水沙条件下，泥沙不能被输送至较远的堤河。经分析计算，本次泥沙落淤量为900万～1350万t，且距口门1．0km范围内落淤泥沙中的82％为粒径大于0．05mm的粗沙。由此得到的主要认识有：①靠自然落淤解决“二级悬河”问题非常困难，甚至会增大“二级悬河”程度；②给漫滩水预留出路是降低淹没损失的关键；③落淤的粗沙使土地产生了十分严重的沙化现象，并且使当地环境趋于恶化。     

雷州半岛地区2015年防旱抗旱工作对策与启示

2015年,广东省雷州半岛地区出现大范围干旱,该文总结了干旱特点,分析了干旱成因,采取了水资源统筹调配、引导调整种植结构及播种时机、人工增雨、筹措资金应急补助等抗旱措施,效果较好。此外,提出该地区今后打造"扩库硬渠上井群"升级版、推进农业结构调整、改善生态环境推动绿色发展的防旱工作对策。     

Operation and Maintenance Performance and Conflicts in Flood-control Projects in Bangladesh

Many embankments failed in severe floods in Bangladesh in 1987 and 1988, and concern grew over ways to improve flood-control projects. Maintenance was poor due to reliance on periodic rehabilitation, but few failures were due to poor construction or maintenance. Embankments mostly failed where they were eroded or were deliberately cut. They were cut by people living outside who believed they were made more flood-prone, and by people living inside because of internal drainage congestion. This reflected inadequate hydrological modelling, lack of consultation and failure to resolve conflicts between affected groups. Resources for maintenance are not generated locally and could be used more efficiently. Participatory planning could reduce conflicts, encourage a sense of project ownership and facilitate contributions to maintenance.     

南京市2016年暴雨洪水分析与思考

2016年汛期,南京市发生了建国以来的大洪水,降雨量和主要河湖水位均超历史.在对2016年暴雨、水情、洪水特点分析的基础上,提出加强南京市防洪工程体系的建议.     

山西省地下水资源开发利用中存在的问题及对策

山西省水资源严重短缺 ,地下水超采严重。分析了地下水资源量及可开采量、地下水开发利用历史和现状 ,以及超采产生的环境地质问题。在此基础上 ,提出了缓解地下水超采、有效合理开发利用地下水的一些措施意见 ,为加强地下水保护和管理提供了科学依据。     

Domestic Water and Sanitation in Cyclones and Floods in Bangladesh and a Proposed Research Agenda

ABSTRACT

Water is one of the top priority item s i relief activities but the appropriateness and effectiveness of this activity may be questioned. Water and sanitation (WS) are inseparable and together they play major roles in the transmission of the pathogen of diarrhoeal disease. Thousands of people die or suffer from WS-related diseases during postdisaster periods. Here we present WS-related experiences gained after Bangladesh's 1991 cyclone and the views of participants in a regional and a national (local) workshop on this matter held in Bangladesh. About 63 per cent of the water purifying tablets (WPTs) distributed after the 1991 cyclone were found to have lost potency Relief personnel lack basic knowledge about WS practices and the management of WS provision. Participants in the two workshops documented serious problems i this field at both regional and national levels. Major issues for research may include: an appropriate environmental preparedness plan; appropriate waste disposal technologies; appropriate water treatment methods; self- help activities during vulnerable periods; and health education related to WS in disaster situations.     

Distribution and removal of Giardia and Cryptosporidium in water supplies in Germany

This study has been conducted, to estimate the distribution of Giardia and Cryptosporidium in German water supplies and the removal efficiency of surface water treatment plants for Giardia and Cryptosporidium by conventional treatment. Water samples from six surface water treatment plants in different parts of Germany were simoultaneously examined for Giardia and Cryptosporidium. Investigations for both parasites were carried out in the period from July 1993 until December 1995. The results confirmed the occurrence of Giardia and Cryptosporidium in surface and raw water, to intermediate steps after treatment, in back wash water, in the first filtrate and in final water. Giardia or Cryptosporidium or both have been found in 76.2% of the investigated raw water sources. The average number of the detected Giardia cysts was 88.2/100 1 (max.1314/100 I), and the average number of Cryptosporidium oocysts was 116/100 I (max. 1081/1001). In the intermediate steps (including flocculation and several steps of filtration), Giardia or Cryptosporidium or both have been found in 33.3% (50/150) of the samples. 14.9% of drinking water samples (7/47) were positive for Giardia (max. 16.8 /1001) and 29.8% (14/47) were positive for Cryptosporidium (max. 20.8/100 I). Overall, Giardia and Cryptosporidium, or both were detected in 38.3% of the drinking water samples. The parasites have been found in nearly all of the investigated backwash water samples. The filtrate of a rapid sand filter was analysed immediately after filter backwashing during the ripening period of the filter. Good elimination results were obtained by optimizing relevant water treatment process, but a low flocculant dose following sudden variation in the raw water quality, causes a breakthrough of Cryptosporidium into the treated water. Although water treatment technologies are effective to remove Giardia and Cryptosporidium, the results clearly show that Giardia and Cryptosporidium evade the filter harries m the absence of visible treatment deficiencies and low turbitidy level, and contaminate final water.     

衡水市地下水开发利用存在的问题及对策

通过对衡水市地下水开发中存在问题的客观分析,提出了今后开发、利用和保护地下水的措施.     

Progress in ecological and environmental water requirements research and applications in China

Abstract:

With economic development, as well as population growth, the conflict between water supply and demand has become more and more acute in China, and it has been aggravated further by the irrational utilization of water resources. As a result, the deterioration and destruction of the eco‐environment have become increasingly serious. In order to effectively protect ecosystems and improve their ecological conditions, many studies on ecological and environmental water requirements (EEWR) have been carried out in China. In this paper, the concept and characteristics of EEWR are addressed, and the main advances of EEWR research and applications in China are summarized in four types of systems including studies on rivers, vegetation, lakes and wetlands, and groundwater. In conclusion, issues necessary to be studied further in the future are put forward.