不同转速下液体透平的性能研究

发布时间：2018-06-29 12:52

本文选题：转速 + 泵作液力透平　；参考：《流体机械》2017年10期

【摘要】：为了明确转速对离心泵作液力透平的性能影响,本文基于Navier-Stokes方程和标准的湍流模型,采用SIMPLE算法,应用商业软件ANSYS-FLUENT对转速分别为750,1000,1500,2000和2900 r/min下的液力透平进行了数值模拟,得到了不同转速下液力透平的外特性曲线。结果表明:对于所研究模型而言,随着转速的不断增大,液力透平最优效率点的效率呈增大趋势,但增加梯度相对较小;最优效率点的流量与转速呈线性增加的趋势;扬程与功率均随着转速的增加而增大,其中扬程在小流量工况时增加梯度较大,而在大流量工况时增加的梯度相对较小;功率的变化规律恰好与扬程变化规律相反,即功率随着转速的增大在小流量工况时增大梯度较小,而在大流量工况时急剧上升。另外,根据不同转速下液力透平的性能特点得出:在小流量工况时,降速对提高液力透平的效率有显著作用,与之对应,在大流量工况运行时,增加转速也可以提高液力透平的能量回收能力,但前提是需要保证结构强度满足要求。总之,该研究结果可对液力透平的经济运行提供部分参考。
[Abstract]:In order to determine the effect of rotating speed on the performance of centrifugal pump hydraulic turbine, based on Navier-Stokes equation and standard turbulence model, the numerical simulation of hydraulic turbine with rotating speed of 750,0001000 / 1500 / 2000 and 2900 r/min was carried out by using simple algorithm and commercial software ANSYS-fluent, respectively. The external characteristic curve of hydraulic turbine at different rotational speeds is obtained. The results show that the efficiency of the optimal efficiency point of hydraulic turbine increases with the increase of rotational speed, but the increasing gradient is relatively small, and the flow rate and speed of the optimal efficiency point increase linearly. Both head and power increase with the increase of rotating speed, in which the gradient of lift increases in small flow condition, but the gradient in large flow condition is relatively small, and the law of power change is opposite to that of head. That is, the power increases with the increase of rotational speed in small flow conditions, but increases sharply in large flow conditions. In addition, according to the performance characteristics of hydraulic turbine at different rotational speeds, it is concluded that when the flow rate is small, the speed drop plays a significant role in improving the efficiency of the hydraulic turbine. The energy recovery ability of the hydraulic turbine can also be improved by increasing the rotational speed, but the premise is that the structural strength meets the requirements. In a word, the results can provide some reference for the economic operation of hydraulic turbine.
【作者单位】：兰州理工大学;甘肃省流体机械及系统重点实验室;流体及动力机械教育部重点实验值(西华大学);
【基金】：国家自然科学基金资助项目(51569013) 甘肃省科技基金计划(17JR5RA110) 流体及动力机械教育部重点实验室(西华大学)开放基金项目(szjj2017-091)
【分类号】：TH311

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