【作者】 张杰；

【导师】 杨玉思；

【作者基本信息】 长安大学 ， 市政工程， 2010， 硕士

【摘要】 为了实现强国之路,我国已经修建了一批重大的调水工程来解决地区间水资源分配的严重不平衡状况,从而实现水资源的优化配置。随着我国西部大开发,振兴东北老工业基地,中部崛起等一系列国家战略的继续推进,各类高扬程、大流量、长距离地形复杂的输水管线工程日益增多。这些工程均是长距离压力管流状态,由水泵提供压力进行输送,但是水泵必然存在开机,关机,操作失误,失去动力或供水阀门动作等。那么压力管路中的管流就会从一个稳定状态到达另一个状态,从而会在管路中产生一系列急剧的压力交替变化的水力过渡过程现象。在过渡过程中,往往会引起过高或过低的水击压力,也可能由于部分泵事故未能及时关闭阀门而产生过大的倒转速度,我们将这种水力撞击现象称为水锤现象。对压力管道输水系统威胁最大的就是水锤问题,泵站中多数水锤事故的结果轻则是水管爆裂,止回阀的上顶盖或壳体被打坏大量漏水,造成暂时供水中断事故,重则酿成泵站被淹没,泵船淹没等严重事故。所以对停泵水锤暂态过程的研究是优化工程设计,降低工程造价,确保工程安全运行的关键,具有重要的理论意义和实用价值。本文详细介绍了刚性水锤理论和弹性水锤理论,因弹性水锤理论以流体为可压缩和管壁为弹性体为基础理论,用其推导出来的基本方程为微分方程组比较符合客观实际。然后介绍了以弹性水锤理论为基础,水锤基本方程式的推导过程,并以此为基础详细说明特征线法的基本原理,导出有限差分方程,介绍了水泵的边界方程。阐述了在停泵水锤暂态过程中,水泵全特性曲线的重要性,并介绍了几种最新的对水泵全特性曲线进行模拟计算的方法。根据水锤基本理论,水锤计算方法及泵的边界条件方程,详细介绍了如何使用水泵全特性曲线计算水锤,分析计算了某地区输水工程水锤,利用Microsoft Visual C++6.0编写水锤计算程序,然后将结果导入Excel中,利用其优良的数据管理功能来分析水锤压力图,给出了较好的水锤防护方案。并通过用不同比转数泵的数值计算,得出水锤升(降)压包络线图。通过比较确定较准确的水泵全特性曲线在水锤防护计算中有十分重要的地位。更多还原

【Abstract】 For realizing way to make the country powerful, our country has already built a number of major inter-regional water transfer project to address the serious imbalances in the distribution of water resources in order to achieve optimal allocation of water resources. But with our country West Development, vitalize the northeast China old industrial base, central section rises abruptly waiting for continue moving forward, many kinds of high-head, high-flow, long-distance water pipeline projects in difficult terrain increasing by gradually. A number of these projects are long-distance pressure pipe flow state and need pressure from water pumps to transmission. The water pump there exists starting up, shut-down in necessity, handles a fault, lose driving force or the valve action supplying water etc. Then the pressure piping in pipe flow will be from one steady state to another state, so that it will produce a series of dramatic pipeline changes in hydraulic pressure alternating transition phenomenon in the transition process..In transient process.it is sometimes able to arouse high or low water attack pressure, and it also may bring about the part pump accident fails to close a valve in time but to produce too big reversion speed. We have this kinds of hydraulic impact phenomenon been known as water hammer phenomenon. Water hammer problems is the greatest threat to pressure pipe distribution system. Most of the results of pumping water hammer incidents ranging from burst water pipes, check valve on the cap or shell were damaged a large number of leaks, causing a temporary supply disruptions and leading to re-pumping station flooded, and pump boat submerged by such serious incidents. So the water hammer process of the pump shut down transient study is the key to optimize the engineering design, to reduce construction costs and to ensure the project operation safe,and has important theoretical significance and practical value.This thesis summarizes the theory of rigid water hammer and the theory of elastic water hammer. The elastic water hammer is based on the assumption that liquid is compressible and tube wall is elastomer, so it accords with the objective realities that the derived equation is differential equations. The thesis introduces the derivative process of the water hammer differential equations, based on the theory of elastic water hammer.Accordingly,the thesis explain the basic principle of the method of characteristic curve and the derivation of finite-difference equations, and pump-side boundary condition equation. In addition, the thesis illustrates the importance of complete pump characteristic curves in the stop pump water hammer transient process and introduces several new calculation methods to simulate the complete pump characteristic curves According to the basic theory of water hammer, water hammer calculation methods and the equations of the pump-side boundary condition described in detail how to use the complete pump characteristic curves to calculate the water hammer,analysis and calculates the water hammer in a water diversion project in an area of Ningxia。Using Microsoft Visual C++6.0 to prepare water hammer calculation program, and then taking the results into Excel, using its superior data management capabilities to analyze the water hammer pressure diagram, giving better water hammer protection program.And numerical through several different specific speed pump and draw the boost(lower) pressure envelope diagram of water hammer. Determined that it is very important by comparing the total more accurate pump characteristic curve in the calculation of water hammer protection position.更多还原