水泵全特性曲线数值化改造的补充及其在停泵水锤计算中不同应用方法的比较研究

发布时间：2018-01-06 16:30

本文关键词：水泵全特性曲线数值化改造的补充及其在停泵水锤计算中不同应用方法的比较研究　出处：《长安大学》2011年硕士论文　论文类型：学位论文

【摘要】：近年来,由于近市水源及河流的污染使得地表水水质恶化,而过度使用地下水又会导致地面沉降,因此我国长距离输水工程逐年增多。随着此类工程的增加,城市给水管道爆破频率普遍提高,而爆管大多数是由于突然停泵引起水锤破坏而造成的。因此,进行停泵水锤计算,预防爆管,是非常必要的。而进行停泵水锤计算的基础是水泵全面性能曲线,由于此类曲线非常复杂,因此在进行停泵水锤电算时,必须首先利用数值法方法将其改造,以供计算机直接调用。而对此,本文进行了如下的研究。 (1)提出了当工程中所用泵的全面性能曲线具有实测资料时,将其数值化以供计算机调用的具体方法。 (2)论述了当工程中所用泵的全面性能曲线实测资料缺乏时,获取工程中所需全特性曲线的两种现有方法,即近似计算方法和通用模型方法；然后分别指出了这两种方法所具有的缺陷；并在通用模型方法的基础上提出了两种新的获取全面性能曲线的方法,即五次多项式拟合的通用模型法以及分类三次多项式拟合的通用模型法。 (3)以水泵性能曲线和水泵比转数为基础,提出一种新的检验模型,用以检验三种通用模型方法的精确性。并利用上述检验方法,结合多组不同比转数的水泵性能曲线,对(2)中的方法做了具体的验算比较。 (4)最后结合咸阳、新疆等地的综合供水工程停泵水锤计算实例,将不同方法所得到的数值化结果对突然停泵时水锤升压的影响进行了比较。最后得出,分类三次拟合的通用模型法是最为精确的。而不同方法得到的水泵全特性曲线的数值化数据在停泵水锤水力过渡过程的计算中,对管道的升压在某些情况下的影响是比较大的。因此在以后的水锤计算中,采用本文所提出的分类三次拟合的通用模型法来减少水锤计算的误差,是非常必要的。
[Abstract]:In recent years, due to the pollution of water sources and rivers near the city, the surface water quality deteriorated, and excessive use of groundwater will lead to land subsidence, so the number of long-distance water conveyance projects in China has been increasing year by year, with the increase of such projects. The blasting frequency of urban water supply pipeline is generally increased, and most of the pipe burst is caused by water hammer damage caused by sudden stoppage of pump. Therefore, the calculation of water hammer stop pump is carried out to prevent pipe burst. It is very necessary. The calculation of water hammer is based on the total performance curve of pump. Because this kind of curve is very complex, it must be reformed by numerical method in the computer calculation of water hammer. For the computer to call directly. And for this, this article has carried on the following research. 1) when the comprehensive energy curve of the pump used in engineering has the measured data, the concrete method of numeralizing it for the computer to call is put forward. 2) when the measured data of the comprehensive energy curve of the pump used in the project are short, two existing methods for obtaining the required full characteristic curve in the engineering are discussed, that is, the approximate calculation method and the general model method; Then the defects of the two methods are pointed out. On the basis of the general model method, two new methods to obtain the total performance curve are proposed, that is, the general model method of the fifth degree polynomial fitting and the general model method of classifying the cubic polynomial fitting. Based on the pump performance curve and pump specific speed, a new test model is proposed to test the accuracy of the three general model methods. Combined with the performance curves of water pumps with different specific rotation numbers, the concrete checking calculation and comparison of the methods used in this paper are made. Finally, combined with the examples of water hammer calculation in Xianyang, Xinjiang and other places, the numerical results obtained by different methods are compared to compare the effect of water hammer pressure rise when the pump is stopped suddenly. Finally, it is concluded that the general model method of classifying cubic fitting is the most accurate, and the numerical data of the full characteristic curve of water pump obtained by different methods are used in the calculation of hydraulic transition process of water hammer. The influence of pressure rise on pipeline pressure in some cases is great, so in the later calculation of water hammer, the general model method of classification cubic fitting proposed in this paper is used to reduce the error of water hammer calculation. It is very necessary.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH38

【引证文献】