双吸离心泵内部流场性能研究及优化设计

发布时间：2018-02-25 21:07

本文关键词： 双吸离心泵湍流模型内部流场导流板优化数值模拟　出处：《东北石油大学》2015年硕士论文　论文类型：学位论文

【摘要】：泵是一种应用范围极其广泛的通用机械,有流体流动的地方,几乎都会有泵在工作。离心泵更是泵类中应用范围最广泛的一种,约占泵类设备总量的70%。双吸离心泵是离心泵的一种重要形式,具有扬程高、流量大、便于检查和维修的特点,越来越受到工程应用的青睐。因此了解双吸离心泵内部流体流动特性,改进双吸离心泵的结构,优化内部流场,提高双吸泵的效率对推动泵行业的发展具有重要且深远的意义。本文对OTS 125-500A型双吸离心泵进行三维建模,将常用于数值模拟的5种湍流模型依次用于离心泵流动仿真过程中。将数值计算结果与试验结果相对比,考虑扬程、效率等性能参数,发现:模拟数据与试验数据基本一致,数值模拟结果可信。在设计工况点处,五种湍流模型对双吸离心泵的适用性都很好,误差值均很小;在小流量工况下,Realizable k??湍流模型得到的计算结果与试验结果更接近;大流量工况下,SST k??湍流模型得到的计算结果精度更高。观察不同工况下离心泵内部流场的流动状态,分析双吸离心泵内部的静压力场、速度场和湍动能分布,得到离心泵内部流场的流动规律。研究结果发现,在叶轮流道内存在“射流-尾迹”现象;由于蜗舌对流体的干扰,在蜗壳流道内产生回流现象,造成大量能量损失,降低离心泵运行效率。根据双吸离心泵内部流场数值模拟结果,在不改变离心泵结构的基础上,将导流板应用于蜗壳流道中以实现双吸离心泵内部流场优化。讨论导流板形状、数量、位置等因素的变化对离心泵内部流场的影响,研究结果表明,弧形导流板更适用于离心泵内部流场优化;由于离心泵喉部流道较为狭窄,考虑效率等性能参数,最终确定只添加一块导流板,并将其安装在蜗壳流道中间位置偏上1/3处效果最佳,在抑制回流现象的同时也可以提升离心泵效率。
[Abstract]:Pump is a kind of universal machinery which has a wide range of applications. Where there is fluid flow, there will almost always be pumps in operation, and centrifugal pumps are the most widely used type of pumps. Double suction centrifugal pump is an important form of centrifugal pump with high lift, large flow rate, easy inspection and maintenance. Therefore, the internal fluid flow characteristics of double suction centrifugal pump are understood, the structure of double suction centrifugal pump is improved, and the internal flow field is optimized. Improving the efficiency of double suction pump has important and far-reaching significance to promote the development of pump industry. In this paper, the three-dimensional modeling of OTS 125-500A double suction centrifugal pump is carried out. Five kinds of turbulence models, which are often used in numerical simulation, are used in the flow simulation of centrifugal pump in turn. By comparing the numerical results with the experimental results, and considering the performance parameters such as lift and efficiency, it is found that the simulated data are basically consistent with the experimental data. The results of numerical simulation are reliable. At the design point, the five turbulence models have good applicability to double suction centrifugal pump, and the error is very small. ? The calculated results obtained by the turbulence model are closer to the experimental results. ? The results obtained by the turbulence model are more accurate. The flow state in the centrifugal pump under different working conditions is observed, and the static pressure field, velocity field and turbulent kinetic energy distribution in the double suction centrifugal pump are analyzed. The flow pattern of centrifugal pump is obtained. The results show that there is a "jet-wake" phenomenon in the impeller passage, and a large amount of energy is lost due to the disturbance of the cochlear tongue to the fluid. According to the numerical simulation results of the internal flow field of the double suction centrifugal pump and without changing the structure of the centrifugal pump, the flow guide plate is applied to the volute runner to optimize the flow field in the double suction centrifugal pump, and the shape of the guide plate is discussed. The effect of quantity, position and other factors on the flow field of centrifugal pump is studied. The results show that the arc guide plate is more suitable for the optimization of flow field in centrifugal pump, because the throat passage of centrifugal pump is narrow, the performance parameters such as efficiency are considered. It is determined that only one guide plate is added and installed in the middle position of the volute channel at 1/3. It can also improve the efficiency of centrifugal pump while restraining the phenomenon of backflow.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH311

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