光照水电站装设筒形阀分析

筒形阀是一种新型的水轮机进水阀,它与球阀或蝴蝶阀相比较有防止机组飞逸事故扩大效果明显、减轻导叶全关时导水机构的快速破坏并减少漏水量,以及动水开启方便、所需时间短等优点,但对运行条件也有一定的要求。光照水电站是贵州省第1个拟采用筒形阀的电站,为此对装设筒形阀的可行性和必要性进行了认真的分析。     

双缸式气动-手动楔式闸阀在柴油罐上的应用

文章简单介绍了气动阀的结构、工作原理及特点,并时堆修保养注意事项以及可能发生的故障和排除故障的方法做了详细讲解。最后,将气动阀在柴油罐上的应用情况与普通闸阀相比较,分析其使用性能和优点,进一步推广气动闽在锦西石化分公司的应用。     

THE STATISTICAL DISTRIBUTION OF EXTREME VALUES OF WAVE-CURRENT FORCES ACTING ON SLENDER CIRCULAR CYLINDER IN IRREGULAR WAVES

Based on model test,the statistical distribution of extreme values of wave-current in-line forces acting on vertical circular cylinder is analyzed in this paper.It is shownthat the results calculated by the simplified method,proposed by authors,agree well with the testdata;Weibull distribution is also adoptable in the region of high KC number, and the shapeparameter a and scale parameter β are related well with KC number respectively.     

三角旋转活塞发动机缸体型线研究

根据三角旋转活塞发动机运动几何原理 ,详细分析了缸体型线。缸体的实际型线是双弧外摆线的等距曲线 ,并由此导出其数学表达式。本文进一步说明了两种几何运动实现方式 ,分析了参数的几何意义 ,并给出其表达式。     

船用低速五缸柴油机推进轴系扭振性能的改进与计算

国内的低速柴油机制造厂 ,船舶设计部门、造船厂和船东好象已经有一种共识 :艉机舱推进轴系使用低速五缸柴油机作主机时 ,都要用扭振减振器。但是 ,只要在设计时合理选用柴油机转速 ,并采用高强度低合金钢来制造中间轴 ,这类轴系大部分是不需要扭振减振器的。     

预应力钢筒混凝土管穿越地下管线的施工措施

文中介绍了预应力钢筒混凝土管的概念、优越性，并结合山西省万家寨联接段引黄工程的实际施工，总结出了穿越各种地下管线的施工经验。     

给水泵密封水系统对机组真空的影响

介绍了银川热电厂二期工程投运一年以后,多次出现凝汽器真空缓慢下降的现象。在机组系统严密性试验合格的前提下,经多次观察,发现是给水泵密封水系统漏空气造成的。在采取了一些相应措施后,解决了这个问题。     

HYDRODYNAMIC FORCE ON SMOOTH HORIZONTAL CYLINDER IN UNIFORM OSCILLATORY FLOW

ＨＹＤＲＯＤＹＮＡＭＩＣ　ＦＯＲＣＥ　ＯＮ　ＳＭＯＯＴＨ　ＨＯＲＩＺＯＮＴＡＬ　ＣＹＬＩＮＤＥＲ　ＩＮ　ＵＮＩＦＯＲＭ　ＯＳＣＩＬＬＡＴＯＲＹ　ＦＬＯＷＨＹＤＲＯＤＹＮＡＭＩＣＦＯＲＣＥＯＮＳＭＯＯＴＨＨＯＲＩＺＯＮＴＡＬＣＹＬＩＮＤＥＲＩＮＵＮＩＦ...     

AN EXPERIMENTAL AND NUMERICAL INVESTIGATION OF THE STARTING FLOW OF A UNIFORMLY ACCELERATING CIRCULAR CYLIINDER

The starting flow around a uniformly accelerated circular cylinder is investigatedby flow visualization techncque and solving N-S equations numerically in detail.The results ofthe starting flow are similar with those of the impulsively started one.At lower Re_α,numbers the“phenomenon a”is revealed;the“phenomenon β”appears at higher Re_α numbers,but withonly one secondary vortex.At the early stage of the starting vortex formation,the flow islaminar;at the later stage,the flow transforms into turbulent flow.The velocity distribution inthe flow field is measured with the multiwires installment.The calculational results are comparedwith the results of experiment,and both are in agreement with each other.