【作者】 张红霞；

【导师】 杨军虎；

【作者基本信息】 兰州理工大学 ， 流体机械及工程， 2009， 硕士

【摘要】 旋喷泵是一种新型特低比转速泵,具有小流量、高扬程、Q-H曲线平坦、结构简单等特点,它比一般的同比转速的离心泵效率要高10-20%左右,广泛应用于石油化工、冶金、造纸、消防等行业。由于国内对于旋喷泵的研究起步较晚,研究不够深入全面,尤其是对于主要过流部件-集流管和转子腔的研究很少,致使该类型泵的效率还较低,应用较少。另外,在已投入使用的旋喷泵中,启动力矩特别大也是应用中存在的一个重要问题,因此研究旋喷泵内的流动规律以及启动特性有着重大的理论价值和良好的应用前景。本文利用FLUENT6.1软件,采用标准k-ε方程紊流模型和SIMPLEC算法,对课题组以前设计的XP300-6型旋喷泵进行了内部流场的数值模拟,对转子腔内液体流动规律进行了重点研究分析,针对旋喷泵在启动过程中会产生很大的力矩的实际问题,对旋转喷射泵的启动特性进行了研究,推导出了针对旋喷泵启动过程的力矩方程。通过研究得到的主要结论如下:（1）通过对旋喷泵转子腔内液体流动规律的数值研究,并对不同轴向长度、不同截面进行分析计算后发现:转子腔内的流体速度随着半径的增加而增大,腔体内液体随着腔体做刚性运动,即每一点的角速度值都是相等的,并且腔内液体的旋转角速度ω_L与腔体的旋转角速度值ω之间的定量关系是ω_L-0.78ω。并且在转子腔轴向长度为90mm-120mm的范围内上述结论都是成立的。（2）集流管进口直径对旋喷泵的性能影响较大,通过研究发现:集流管进口名义尺寸可按d_计算-（?）计算,另外需要考虑集流管进口处的缩孔效应。对集流管进口处因缩孔效应进行研究,得到了缩孔厚度δ与管道直径d之间的数值关系:δ=0.2d。进而得到了集流管进口实际尺寸与计算尺寸之间的关系:d_实际=1.2d_计算,计算结果取整。该结论对设计集流管具有指导意义。（3）分析了影响旋喷泵启动力矩大小的因素:叶轮、转子腔、腔内液体及集流管,通过推导得到了旋喷泵的启动力矩公式。通过推导出的旋喷泵启动力矩公式发现:旋喷泵的启动力矩与启动加速度有很大关系,启动加速度越大,启动力矩越大,另外还与转子腔腔体的径向长度有关,转子腔腔体的径向长度越大,启动力矩越大。更多还原

【Abstract】 The Roto-Jet pump is a new kind of very low specific speed pump, which has many characters, such as low flux, high pressure, smooth Q-H curve, simple construction. Its efficiency is higher about 10-20% than the centrifugal pump which is at the same specific speed. It is always used in the industry of oil, chemical, metallurgy, paper making, fire fighting. Because start relatively late in fastening the research of gushing out the pump at home, it is not deep enough and overall to study, especially of the pick-up tube and rotor cavity, it is still relatively low to cause the efficiency of this type pump. Besides that, there also is a terrible problem in the use of the Roto-jet pump, which is huge startup momentum. So the Roto-Jet pump is less to use. Therefore, it has very important theory value and well applicable foreground to research in the rule of the flow field inside and the startup characteristic of the Roto-Jet pump.The standard k-e turbulence model and SIMPLEC algorithm are applied to analyze the full flow passage of the type XP300-6 Roto-Jet pump designed by the studying team before by FLUENT6.1 in this thesis, and the flow regularity in the rotor cavity was analyzed emphatically. Aiming at the practical problem of the producing huge momentum of startup, the startup characteristic is studied and the expressions for the momentum of startup is work out. The main conclusions are as follows:（1） Though the research on the rotor cavity’s flow regularity and analysis calculation of the different lengths and different sections, we can draw the conclusions: the fluid velocity is bigger with the radial increasing. The fluid does rigid movement with the cavity, it means that every fluid point’s angular velocity is the same, theconnection between the fluid’s angular velocityω_L and the rotor cavity’s angularvelocityωisω_L = 0.78ω. This conclusion is correct when the axial length isbetween 90mm and 120mm.（2） The influence of the inlet diameter of the pick-up tube on the capability of the roto-jet pump is great. Though research, the nominal size of the inlet diameter can be got by the expression of d_计算 = （?）, in addition, the shrinkage effect in the inlet ofthe pick-up tube needs to be considered. Though research on the shrinkage effect, the connection between the shrinkage thicknessδand the piping diameter d is found:δ= 0.2d and the connection between the trim size and the calculation size of the pick-up tube inlet is also worked out: d_实际 =1.2d_计算, the result adopt integer. Thisconclusion has guiding significance for the designing pick-up tube.（3） The influence of the impeller, the cavity, the fluid in the cavity and the pick-up tube on the momentum of startup is analyzed and the expressions for the momentum of startup is work out though deduction.Through the expression we can find that the startup momentum is related with the angle acceleration and the radial length of the rotor cavity. The angle acceleration and the radial length of the rotor cavity are bigger, the startup momentum is huger.更多还原