立式双级自吸泵的水力性能与自吸特性研究

发布时间：2018-06-18 16:21

本文选题：立式双级自吸泵 + 结构改进　；参考：《浙江大学》2017年硕士论文

【摘要】：自吸式离心泵因其具有良好的自吸性能而在二次启动时无需灌泵,便于自动化控制,广泛适用于重要的工农业领域。随着各类应用场合对泵能耗要求的提高,市场上广泛应用的立式自吸泵的效率、运行平稳性和自吸性能已越来越难以满足应用的需求。本文在研究和分析传统立式单级自吸泵的基础上,开发了立式双级自吸泵,基于局部欧拉能量分布的调整,改进了叶轮内部能量分布,提高自吸泵水力性能,提出了新的蜗壳气液分离室结构,并改进了口环密封结构及副叶轮结构。借助计算流体动力学(CFD)软件对双级自吸泵的水力模型进行了优化和性能预测,最终开发产品进行现场应用。同时,本文的双级自吸泵无回流孔的结构特点,基于两相流动模拟研究了所开发自吸泵的自吸特性。为优化立式双级自吸泵的性能并研究其自吸特性,本文主要开展了以下几个方面的工作:(1)总结概括已有典型自吸泵的研究成果以及国内外研究现状,研究和分析立式单级自吸泵的主要问题,在此基础上设计出双级立式自吸泵,并对其水力性能和自吸特性进行了研究;(2)基于CFD分析软件FLUENT,采用κ-ε湍流模型对自吸泵内部流场进行单相定常数值模拟和性能预测;根据定常数值模拟结果对自吸泵叶轮蜗壳以及叶轮内部结构进行改进,对比与分析不同结构对自吸泵流场的影响,设计得到了高效的立式双级自吸泵叶轮、蜗壳及泵内部结构;(3)对立式双级自吸泵进行性能试验,通过泵性能测试数据与模拟数据结果对比,验证设计的合理性和计算方法的可靠性;(4)基于FLUENT软件对立式双级自吸泵自吸过程的气液两相流进行非定常数值模拟。给出了自吸过程泵内含气率、速度和压力的分布规律及流动特征,分析了叶轮进出口、蜗壳进出口和气液分离室压力与含气率,并结合理论分析研究其自吸过程。本文提出了新型立式双级自吸泵结构,基于CFD数值模拟改进设计了自吸泵的过流部件,分析了自吸过程的泵内气液两相流结构流场,完成了产品样机的制造、试验和现场应用,测试和应用结果显示,所开发的双级立式自吸泵效率相比传统立式自吸泵得到大幅度提升,且自吸性能良好,达到了节能降耗的目的。本文的研究工作对立式自吸泵产品研发与应用具有一定的参考价值。
[Abstract]:Because of its good self-priming performance, self-priming centrifugal pump does not need pumping during secondary start-up, which is convenient for automatic control and is widely used in important fields of industry and agriculture. With the improvement of pump energy consumption requirements in various applications, the efficiency, running stability and self-priming performance of vertical self-priming pumps, which are widely used in the market, have become more and more difficult to meet the needs of application. Based on the research and analysis of the traditional vertical single stage self-priming pump, a vertical two-stage self-priming pump is developed. Based on the adjustment of the local Euler energy distribution, the internal energy distribution of the impeller is improved and the hydraulic performance of the self-priming pump is improved. A new structure of volute gas-liquid separation chamber is proposed, and the sealing structure of orifice ring and the structure of secondary impeller are improved. The hydraulic model of the two-stage self-priming pump was optimized and its performance was predicted by using the computational fluid dynamics (CFD) software. Finally, the product was developed for field application. At the same time, the self-priming characteristics of the two-stage self-priming pump without reflux hole are studied based on two-phase flow simulation. In order to optimize the performance of the vertical two-stage self-priming pump and study its self-priming characteristics, this paper mainly carried out the following work: 1) summarizing the research results of the typical self-priming pump and the research status at home and abroad. The main problems of vertical single stage self-priming pump are studied and analyzed. On this basis, a two-stage vertical self-priming pump is designed. Based on the CFD software fluent, the single-phase steady numerical simulation and performance prediction of the flow field in the self-priming pump are carried out by using 魏-蔚 turbulence model. According to the steady numerical simulation results, the volute and the internal structure of the self-priming pump impeller are improved, and the influence of different structures on the flow field of the self-priming pump is compared and analyzed, and an efficient vertical two-stage self-priming pump impeller is designed. The volute and pump internal structure are used to test the performance of a two-stage self-priming pump. The performance data of the pump are compared with those of the simulation data. To verify the rationality of the design and the reliability of the calculation method the unsteady numerical simulation of the gas-liquid two-phase flow in the self-priming process of the two-stage self-priming pump is carried out based on fluent software. The distribution law and flow characteristics of gas content, velocity and pressure in pump during self-priming process are given. The pressure and gas content in impeller inlet and outlet, volute inlet and outlet and gas-liquid separation chamber are analyzed, and the self-priming process is studied by theoretical analysis. In this paper, a new type of vertical two-stage self-priming pump is proposed. Based on the CFD numerical simulation, the flow field of the gas-liquid two-phase flow structure in the pump is analyzed, and the manufacture, test and field application of the prototype are completed. The results of test and application show that the efficiency of the developed two-stage vertical self-priming pump is greatly improved than that of the traditional vertical self-priming pump, and the self-priming performance is good, which achieves the purpose of saving energy and reducing consumption. The research work in this paper has some reference value for the research and application of self-priming pump.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH311

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