空气罐水锤防护的并联泵系统水力振动分析  

Hydraulic vibration analysis of parallel pump system with air surge tank for water hammer protection

作　　者：于永海[1] 王金星[1] 秦晓峰[1] 

机构地区：[1]河海大学水利水电学院,江苏南京210098

出　　处：《排灌机械工程学报》2013年第11期958-963,共6页Journal of Drainage and Irrigation Machinery Engineering

基　　金："十二五"国家科技支撑计划项目(2012BAD08B03)

摘　　要：针对常见的以空气罐为水锤防护装置的并联泵系统,建立了进、出水池间的传递矩阵,用迭代法对复变量方程进行了求解,得到了系统自振频率及其对应振型.以某长距离供水工程为例进行了水力振动计算,得到了14阶系统自振频率及其振型,其中第1,14阶自振频率分别为0.010 6,0.183 3 Hz,自振频率低,仅当扰动源为低频扰动时才可能发生水力共振;系统各阶衰减因子均为负值,表明系统是稳定的,不会出现自激振动;把实例泵系统第8管段的PVC-M管改为焊接钢管,对系统进行了水力振动计算.由于管材改变,水锤波速增大,空气罐空气容积增大,各阶自振频率都增大,波谷、波峰出现的位置不同,压力与流量振幅增大,表明水锤波速对系统自振频率及其振型影响很大,因此在水力振动分析时,对管材、水中含气量等影响水锤波速的因素要引起足够的重视.For usual parallel pump systems with air surge tank for water hammer protection,the transfer matrix of pump system was established between suction and discharge sumps in a pumping station.The equations of transfer matrix with complex variable were solved by the iteration method and then the natural frequencies and their corresponding modes were obtained for free vibration. A hydraulic vibration analysis was conducted for a long pipe water supply project,and 1st-14th self vibration frequencies and their modes were obtained,in which the natural frequencies of 1st and 14th are 0. 010 6 Hz and 0. 183 3 Hz,respectively. It was showed that because the self vibration frequency is too low hydraulic resonance cannot occur until the water supply system is subject to a disturbance source with an even low oscillating frequency. The attenuation factor of every order is negative,thus the system always is stable and self-excited vibration will never happen. After the eighth PVC-M pipe segment of the system was changed to a steel one,the same hydraulic vibration analysis was repeated. Because the water hammer wave speed is increased by the change in mechanical property of pipe wall material,the air volume in the air surge tank,self vibration frequency and amplitudes of pressure and flow rate oscillation are increased as well. This indicates that the water hammer wave speed has a significant influence on self vibration frequency and its modes of free vibration. Therefore,the factors such as material of pipe wall,air volume in water etc should be paid enough attention in a hydraulic vibration analysis since they can alter water hammer wave speed.

关 键 词：并联泵系统 空气罐 自振频率 振型 水锤 

分 类 号：TH[机械工程]