节点文献
多级离心式森林消防泵的抗汽蚀性能研究
Research on Cavitation of Multistage Centrifugal Forest Fire-extinguishing Pump
【作者】 宋杨；
【导师】 于文华；
【作者基本信息】 北京林业大学 ， 机械设计及理论， 2012， 硕士
【摘要】 汽蚀是水轮机、水泵等水力机械中产生的一种特有现象。离心泵在使用时,如果安装高度过高或者吸水管路布置不合理,泵内容易产生汽蚀现象。汽蚀现象的出现严重影响了泵的正常工作,降低了泵的寿命。泵汽蚀余量大小是评价离心泵性能好坏的一项重要指标。本文以BJL三级离心式森林消防泵为研究对象,分别使用试验方法与数值模拟方法对其汽蚀性能进行分析。在现有水泵测试平台的基础上,完成了开式泵汽蚀试验系统的搭建设计工作,对消防泵进行了性能测试试验和汽蚀试验。使用CFD软件ANSYS CFX对消防泵进行了整机流场的单相流模拟以及首级叶轮的两相汽蚀模拟,将模拟结果与试验结果进行了对比,验证了使用数值模拟方法分析该系列消防泵的可行性。数值模拟的结果显示了泵内部的压力分布与叶轮内汽蚀现象产生的气泡分布,为下一步消防泵的综合优化提供参考依据和研究方法。得到了三级离心式森林消防泵的临界汽蚀余量,对该水泵在实际使用中安装高度的确定提供计算依据,并计算得到了水泵在特定使用条件下的许用安装高度,结果显示消防泵的安装高度达到了设计要求。
【Abstract】 Cavitation is a peculiar phenomenon which appears in turbine, water pumps and other hydraulic machineries. If installed too high or bibulous pipeline layout is not reasonable, cavitation may occur in centrifugal pump.Cavitation has seriously affected the normal performance of the pump and reduces the pump life, especially for low specific speed pump. NPSH is an important indicator to evaluate the performance of centrifugal pump.This research analyzes the BJL three-stage centrifugal forest fire-extinguishing pump cavitation performance by using testing method and numerical simulation. On the basis of the existing pump testing platform, I designed and constructed the open-type pump cavitation test system, and completed the performance test and cavitation test of centrifugal pump. Besides, I simulated the single-phase flow in the internal flow field of multi-stage centrifugal pump and cavitation in the flow field of the first-stage impeller by using ANSYS CFX software. Results of simulations and experiments were compared to verify the numerical simulation results are relatively feasible and reliable. The numerical simulation results show the pressure and bubble volume fraction distribution in the internal flow field of centrifugal pump, which provides a reference and research method for the integrated optimization design of centrifugal pump. Obtained the value of NPSHc of three-stage centrifugal forest fire-extinguishing pump, which provides a basis for determining the installation height of this series of centrifugal pumps,and calculated the allowable installation height of centrifugal pump in some particular using conditions, Results shows that the centrifugal pump suction height achieves the design requirement.