自动抓梁的设计与应用

自动抓梁是利用移动式启闭设备操作闸门及拦污栅的配套设备,在水电水利工程中已经被广泛的应用。自动抓梁的设计一直是根据工程实际套用或改装已建工程的抓梁,虽然没有一套完整的标准,但技术已经成熟。本文根据自己的设计实践及对应用成果分析,总结了自动抓梁设计与运用中应注意的问题,并提出了解决问题的建议和方法。     

自动抓梁设计的探讨

详细介绍了自动抓梁的挂、脱钩原理及主要部件的设计过程,剖析了其设计中应注意的一些问题,并提出了解决方法。     

葛洲坝电站门机液压自动抓梁改造

根据门机液压自动抓梁运行中的常见故障,提出改进意见,通过已有液压自动抓梁的改进,提高了运行操作可靠性,保证了闸门的启闭安全,并提出了自动抓梁运行操作的注意事项。     

辽宁双岭水利枢纽通用自动抓梁设计

在水电站设计中,电站进口设置移动式启闭机配置抓梁起吊拦污栅及闸门是经常遇到的布置型式,常规设计是根据孔口及门槽尺寸设计不同的抓梁,需要启吊时再拆换抓梁。在双岭水利枢纽工程中设计了一种能够适应不同门槽宽度的抓梁,实现了一套抓梁既可以启吊拦污栅又可以启吊闸门,灵活方便。不但节省投资,降低了劳动强度,而且大大提高了工作效率,而且经过实践检验运行是可靠的。本文对抓梁的结构进行了介绍。     

液压自动抓梁设计及其制造

在水利枢纽工程中自动抓梁作为移动式启闭设备的一项重要配套设备,现在广泛运用于操作闸门及拦污栅的提升.本文以福建省罗源霍口水库工程SME2×250 kN门式起重机配套的液压抓梁为例,主要介绍了液压式自动抓梁的设计制造,以及对可能出现一些常见的问题,进行初步的探讨与研究,并提出点建议和解决方法.     

机械抓梁互锁式挂脱装置的研制

介绍一种新型的机械抓梁的挂脱装置——互锁式挂脱装置的结构和工作原理。与现有的挂脱装置相比,该装置具有自动化程度高、安全可靠的特点。     

闸门启闭机自动抓梁改进建议

1概况三峡工程闸门及门机经多年运行,2008年发现部分自动抓梁移轴装置卡阻,销轴表面拉伤;油箱罐上下两部分之间的密封件损坏导致泵站进水;电磁阀受潮后失灵;在检修中发现轴与套的几何尺寸及配合存在问题,支撑环磨损严重并在低温时易断裂;放油不方便等.针对存在的问题,对坝顶现用的多台抓梁移轴装置进行了现场观察,测量及对比,对进水口检修门抓梁使用和维修中出现的问题进行了解,走访了设计和监造单位,综合分析后对三峡工程进水口检修门抓梁存在的问题提出了改进和优化设计、对使用保养提出了建议.由于以上问题存在普遍性,应邀发表此文供同行参考.     

自动抓梁在水电工程中的应用

文中介绍了挂脱自如式和液压式两种型式自动抓梁在水电工程中的应用情况,着重论述了这两种型式自动抓梁的特点、使用过程中应注意的问题和适用范围,以及这两种型式自动抓梁在水电工程应用中的形势和发展方向,为设计人员在设计过程中的选型提供参考.     

大跨度液压自动抓梁的设计与制造

介绍了液压自动抓梁的运行原理,并对大跨度液压自动抓梁体设计、穿销装置、传感信号系统等关键部件设计和加工制造中须注意的要点进行了阐述,以资同行们在设计制造过程中相互借鉴、探讨。     

大化水电站左岸桥机液压自动抓梁改造

围绕大化水电站液压自动抓梁自身存在的问题开展原因分析,提出了改进思路和设计方案,不但提高了工作效率和安全可靠性,保证了闸门的启闭安全,同时具有结构简单、投资省和维护方便的优点.     

浮冰块底面水压力分布的数值模拟研究

冰块运动过程中遇到冰盖等阻碍时,将有可能停滞或下潜.冰块的运动形式与作用在冰块上的力有密切关系.本文采用VOF法追踪自由水面,结合RNG k-ε紊流模型,对浮冰块底面水压力分布进行了数值模拟.通过与Dow Ambtman物理模型试验数据的对比,验证了该数值模拟方法的合理性和可靠性.模拟分析发现冰块底面水压力与冰块前缘形状、冰厚和流速均有关系:前缘圆形断面冰块比前缘矩形断面冰块有着较弱的前缘分流效应和相同的文丘里效应;冰厚、流速增大时,冰块底面的压差增大,冰块前缘最大压差的范围也增大,且压强恢复速度变慢.     

Flexural-gravity wave resistances due to a moving point source on 2-D infinite floating beam

The flexural-gravity wave responses due to a load steadily moving or suddenly accelerated along a rectilinear orbit are analytically studied within the framework of the linear potential theory. A thin viscoelastic plate model is used for a very large floating structure. The initially quiescent fluid in the ocean is assumed to be homogenous, incompressible, and inviscid, and the disturbed motion be irrotational. A moving line source on the plate surface is considered as a moving point in the two-dimensional coordinates. Under the assumptions of small-amplitude wave motion and small plate deflection, a linear fluid-plate coupling model is established. The integral solutions for the surface deflections and the wave resistances are analytically obtained by the Fourier transform method. To study the dynamic characteristics of the flexural-gravity wave response, the asymptotic representations of the wave resistances are derived by the residue theorem and the methods of stationary phase. It shows that the steady wave resistance is zero when the speed of moving load is less than the minimal phase speed. The wave resistances due to the accelerate motion consist of two parts, namely the steady and transient wave responses. Eventually the transient wave resistance declines toward zero and the wave resistance approaches the steady component as the time goes to the infinity. Furthermore, the effect of the strain relaxation time for this viscoelastic plate is studied and it exhibits more influence for a high-speed motion.     

Stresses in the foundation of the floating block of the kislaya guba tidal power station

Conclusions The results of measuring the stresses reflect the successful conduction of the operations of setting the block on the artificial foundation and even placement of the block both in the dock and at the site of the tidal power station. Experience at the Kislya Guba tidal power station shows that soil and piezodynamometers cna be used successfully for investigating stresses in the foundation of a floating structure under marine conditions when the following necessary conditions are observed: a) a piezodynamometer must be placed alongside of each soil dynamometer; b) higher requirements must be imposed on the elimination of lateral fastening of instruments; c) the instrument must be reliably protected against corrosion and fouling by marine microorganisms; d) special attention must be given to the commutation of instruments (it is necessary to investigate the reliability of lengthening the cables under seawater conditions on instruments installed at the Kislaya Guba tidal power station). The installation of instruments by the underwater method made it possible to reveal the most vulnerable places of these operation, i.e., to find places for installing the instrument and protecting the cables under water. However, this matter requires additional development. In so doing, particular attention should be given to effective control of the performance of this operation by divers. The conduction of full-scale observations during the operating period will make it possible to obtain a more clear-cut picture of the change of stresses in the foundation of the block of the Kislaya Giba tidal power station as a function of the variable head. Complied on the basis of results of full-scale observations. The construction and operation of the Kislaya Guba tidal power station are described in [1]. Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 11, pp. 7–9, November, 1971.     

Nonlinear dynamic characteristics of a multi-module floating airport with rigid-flexible connections

This paper studies the dynamics of a multi-module floating airport with flexible connectors using the network theory. A mathematical model for a chain-type topology structure is developed by using the wave theory, and the models of a single floating module and the connector and mooring system. The nonlinear dynamics of the floating airport and the connector force are studied. A remarkable phenomenon of amplitude death is observed, as a weak oscillation state of all floating modules, an important state for the system global dynamic stability. The parametric domain for the onset of amplitude death is identified, and the effects of the wave height and the number of the floating modules on the dynamic stability are discussed. An application of the network theory in the marine engineering is illustrated with the introduction of a new concept for global dynamic stability for the floating airport.     

有漂浮植物河道水流的雷诺应力研究

水生植物的种植改变了原先河道的水流结构，影响了水体的水流特性．通过室内试验，分析了在河道种植风眼莲前后水流时均流速和雷诺应力的变化．试验结果表明，风眼莲对各向时均流速和雷诺应力的分布影响明显，且不同种植方式的影响程度也不同．     

日本湿地净化技术人工浮岛介绍

由于人类大规模的开发建设活动,使原来的自然环境发生了很大的变化,特别是湿地面积不断缩小、水质日益恶化造成了河流、湖沼、池塘等水生态的严重破坏.世界上一些国家特别是日本把生态系统保护的重点放在湿地上,目前正在为恢复生态环境、保护生物的生息空间、创造优美的绿色景观、净化河川、湖沼水质而努力.在此,介绍的人工浮岛技术是日本的专门研究机构近年来一直在进行研究并在实践中取得一定成果的科研项目,值得我国借鉴.     

有关管道穿梁留洞的若干建议

在工业和民用建筑设计中,给水及消防管道等穿梁敷设,对于节省建筑层高、减少管道支吊架用量、降低安装工程造价作用明显。但是,在预留穿梁套管时,如果与结构专业梁板的布置形式结合不够密切,则起不到应有的效果,甚至造成较大浪费。结合某卷烟厂联合工房在管道安装过程中发现的问题,对管道穿梁安装提出了具体建议。