喷射泵性能计算及防汽蚀装置性能研究

发布时间：2018-05-11 03:38

本文选题：喷射泵 + 数值计算　；参考：《大连理工大学》2011年硕士论文

【摘要】：喷射泵是一种用来传递能量、质量的流体机械设备。在喷射泵中两股不同压力的流体相互混合,发生能量交换后形成一种居中压力的混合流体。喷射泵提高引射流体的压力而不直接消耗机械能,并且由于它自身具有的独特优点如工作可靠、没有转动部件、安装维护方便等受到人们的青睐而被广泛的应用到了工程实际的各个领域中。本文通过商用软件FLUENT对喷射泵的内部流场进行分析,并在此基础上分析了喷射泵结构参数和工作参数及其变化对喷射泵性能的影响。应用喷射泵的引射增压功能,设计了输送高温饱和水的离心式水泵的防汽蚀装置,同时对防汽蚀装置的工作性能进行了深入的研究。本文的主要工作如下： 1.根据能量守恒原理和动量守恒原理推导出喷射泵的性能曲线及最佳截面比的公式,为防汽蚀装置中喷射泵的设计计算和性能分析奠定基础。 2.针对喷射泵进行物理和几何建模,应用商用软件FLUENT分析喷射泵内部流动压力和速度的变化。并且分析了喉管入口收缩角对喷射泵性能的影响,经过计算本文发现喉部入口收缩角在20°至45°之间白选取对喷射泵的效率影响不大,并且发现喉部入口收缩角较小时喷射泵更容易发生汽蚀。 3.在喷射泵数值计算的基础上分析截面比为6-11的喷射泵的工作压力、引射压力、出口混合压力对其性能的影响以及当喷射泵总扬程不变时吸上高度和排出压力与流量比之间的关系。 4.在喷射泵内部流场、性能分析的基础上,建立基于喷射泵的防汽蚀装置性能计算模型。并对防汽蚀装置的变工况运行规律进行研究。
[Abstract]:Jet pump is a kind of fluid mechanical equipment used to transfer energy and mass. In the jet pump, two fluids with different pressures are mixed with each other, and after energy exchange, a mixed fluid with intermediate pressure is formed. The jet pump increases the pressure of the jet fluid without directly consuming mechanical energy, and because of its unique advantages such as reliability of operation, no rotating parts, The convenience of installation and maintenance has been widely used in various fields of engineering. In this paper, the internal flow field of the jet pump is analyzed by commercial software FLUENT, and on this basis, the influence of the structural and working parameters of the jet pump and its variation on the performance of the jet pump is analyzed. The cavitation protection device of centrifugal pump conveying high temperature saturated water is designed by using ejection and supercharging function of jet pump. At the same time, the working performance of anti-cavitation device is deeply studied. The main work of this paper is as follows: 1. According to the principle of energy conservation and momentum conservation, the formula of the performance curve and the optimum cross section ratio of the jet pump is derived, which lays a foundation for the design calculation and performance analysis of the jet pump in the cavitation protection device. 2. Based on the physical and geometric modeling of the jet pump, the variation of flow pressure and velocity in the jet pump was analyzed by the commercial software FLUENT. The effect of throat inlet contraction angle on the performance of jet pump is analyzed. It is found that the throat inlet contraction angle between 20 掳and 45 掳has little effect on the efficiency of jet pump. It is also found that cavitation is more likely to occur at the throat entrance than with a small jet pump. 3. Based on the numerical calculation of the jet pump, the working pressure and the ejection pressure of the jet pump with the cross section ratio of 6-11 are analyzed. The effect of outlet mixing pressure on its performance and the relationship between suction height and the ratio of discharge pressure to flow rate when the total head of the jet pump is constant. 4. Based on the analysis of internal flow field and performance of jet pump, the performance calculation model of anti-cavitation device based on jet pump is established. At the same time, the operation law of anti-cavitation device under different working conditions is studied.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH38

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