叶轮出口宽度对离心泵非定常性能的影响
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摘要
为了研究设计工况下不同的叶轮出口宽度对离心泵非定常性能的影响,以一台比转速为66的离心泵为研究对象,保证设计模型其他几何参数不变的前提下,对叶轮出口宽度分别为11、12、13、14、15 mm的离心泵模型进行数值模拟计算,分析其外特性、内部流场以及压力脉动的变化规律。结果表明:叶轮出口宽度对离心泵的外特性有显著影响,出口宽度越大,扬程越高,存在一个最佳的叶轮出口宽度使离心泵在设计工况下效率最高,即b=14 mm;随着出口宽度的增大,叶轮和蜗壳的压力增大,叶轮流道内低速区面积增加,湍动能减小;蜗壳流道内监测点的压力脉动幅值随叶轮出口宽度的增加而增加,隔舌和出口处监测点的压力脉动幅值随出口宽度的增加呈先减小后增加的趋势,在b=14 mm时压力脉动幅值最低。综合分析:说明存在一个最佳的叶轮出口宽度使离心泵性能最佳,为比转速为66的离心泵的水力设计提供一定的参考价值。
In order to study the effect of different impeller outlet widths on the unsteady performance of centrifugal pumps under design conditions,a centrifugal pump with a specific speed of 66 is selected as the research object. The numerical simulation of centrifugal pump models with impeller outlet widths of 11,12,13,14 and 15 mm is conducted. An analysis is made of its external characteristics,internal flow field,and the variation of pressure pulsation. The results show that the impeller outlet width has a significant effect on the external characteristics of the centrifugal pump. The larger the outlet width and the higher the lift,there is an optimal impeller outlet width so that the centrifugal pump has the highest efficiency under the design conditions,ie,b = 14 mm. With the increase in outlet width,the pressure of impeller and volute increases,the area of low velocity area in the impeller flow channel increases,and the turbulent kinetic energy decreases.The pressure pulsation amplitude of the monitoring point in the scroll flow channel increases with the increase in the impeller exit width. The pressure pulsation amplitudes at the monitoring points of the lapped tongue and the exit point first decreases and then increases with the increase in the outlet width,and the pressure pulsation amplitude is the lowest at b = 14 mm. A comprehensive analysis shows that there is an optimal impeller outlet width to optimize the performance of the centrifugal pump,which provides a certain reference value for the centrifugal pump hydraulic design with a specific speed of 66.
In order to study the effect of different impeller outlet widths on the unsteady performance of centrifugal pumps under design conditions,a centrifugal pump with a specific speed of 66 is selected as the research object. The numerical simulation of centrifugal pump models with impeller outlet widths of 11,12,13,14 and 15 mm is conducted. An analysis is made of its external characteristics,internal flow field,and the variation of pressure pulsation. The results show that the impeller outlet width has a significant effect on the external characteristics of the centrifugal pump. The larger the outlet width and the higher the lift,there is an optimal impeller outlet width so that the centrifugal pump has the highest efficiency under the design conditions,ie,b = 14 mm. With the increase in outlet width,the pressure of impeller and volute increases,the area of low velocity area in the impeller flow channel increases,and the turbulent kinetic energy decreases.The pressure pulsation amplitude of the monitoring point in the scroll flow channel increases with the increase in the impeller exit width. The pressure pulsation amplitudes at the monitoring points of the lapped tongue and the exit point first decreases and then increases with the increase in the outlet width,and the pressure pulsation amplitude is the lowest at b = 14 mm. A comprehensive analysis shows that there is an optimal impeller outlet width to optimize the performance of the centrifugal pump,which provides a certain reference value for the centrifugal pump hydraulic design with a specific speed of 66.
引文
[1]欧顺冰,刘小兵,曾永忠.基于CFX的中比转速离心泵的性能特性预测[J].水力发电,2012,38(6):62-65.
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[3] Gulich J F.Centrifugal Pumps[M]. London:Springer,2010.
[4]刘厚林,丁剑,谈明高,等.叶轮出口宽度对离心泵噪声辐射影响的分析与试验[J].农业工程学报,2013,29(16):66-73.
[5]戴菡葳,刘厚林,丁剑,等.离心泵叶轮出口宽度对泵腔内压力脉动分布的影响[J].排灌机械工程学报,2015,33(1):20-25.
[6]董亮,代翠,孔繁余,等.叶片出口安放角对离心泵作透平噪声的影响[J].农业工程学报,2015,31(6):69-75.
[7]张德胜,施卫东,李通通,等.轴流泵叶轮出口尾迹区非定常压力和速度场特性[J].农业工程学报,2012,28(17):32-37,293.
[8]李学臣,席光.离心叶轮出口流动分离区影响因素的数值研究[J].西安交通大学学报,2013,47(9):16-22.
[9]蒋庆磊,翟璐璐,吴大转,等.多级离心泵内叶轮出口压力脉动研究[J].工程热物理学报,2012,33(4):599-602.
[10]柴立平,叶欢,任志明,等.叶轮参数对泵出口压力脉动的影响[J].排灌机械工程学报,2016,34(8):645-650.
[11]金永鑫,宋文武,符杰,等.低比转速离心泵叶片加厚非定常特性分析[J].热能动力工程,2016,31(2):53-58,137-138.
[12]郝治邦,杨中强.前后盖板长度对离心泵外特性与非定常特性的影响[J].灌溉排水学报,2017,36(8):46-52.
[13]赵伟国,刘明,刘宜,等.叶片厚度对低比转数离心泵性能的影响[J].排灌机械工程学报,2015,33(12):1 033-1 037.
[14]刘厚林,丁剑,谈明高,等.叶轮出口宽度对离心泵噪声辐射影响的分析与试验[J].农业工程学报,2013,29(16):66-73.
[15]陈然伟,曾永忠,刘小兵.短叶片包角对离心泵水力性能影响的数值研究[J].中国农村水利水电,2015,(10):122-125.
[16]江伟,李国君,张新盛.离心泵叶片出口边倾斜角对压力脉动的影响[J].排灌机械工程学报,2013,31(5):369-372,378.
[2]葛书亭,宋文武,符杰,等.叶片包角对低比转速离心泵性能的影响[J].水泵技术,2015(05):13-16,20.
[3] Gulich J F.Centrifugal Pumps[M]. London:Springer,2010.
[4]刘厚林,丁剑,谈明高,等.叶轮出口宽度对离心泵噪声辐射影响的分析与试验[J].农业工程学报,2013,29(16):66-73.
[5]戴菡葳,刘厚林,丁剑,等.离心泵叶轮出口宽度对泵腔内压力脉动分布的影响[J].排灌机械工程学报,2015,33(1):20-25.
[6]董亮,代翠,孔繁余,等.叶片出口安放角对离心泵作透平噪声的影响[J].农业工程学报,2015,31(6):69-75.
[7]张德胜,施卫东,李通通,等.轴流泵叶轮出口尾迹区非定常压力和速度场特性[J].农业工程学报,2012,28(17):32-37,293.
[8]李学臣,席光.离心叶轮出口流动分离区影响因素的数值研究[J].西安交通大学学报,2013,47(9):16-22.
[9]蒋庆磊,翟璐璐,吴大转,等.多级离心泵内叶轮出口压力脉动研究[J].工程热物理学报,2012,33(4):599-602.
[10]柴立平,叶欢,任志明,等.叶轮参数对泵出口压力脉动的影响[J].排灌机械工程学报,2016,34(8):645-650.
[11]金永鑫,宋文武,符杰,等.低比转速离心泵叶片加厚非定常特性分析[J].热能动力工程,2016,31(2):53-58,137-138.
[12]郝治邦,杨中强.前后盖板长度对离心泵外特性与非定常特性的影响[J].灌溉排水学报,2017,36(8):46-52.
[13]赵伟国,刘明,刘宜,等.叶片厚度对低比转数离心泵性能的影响[J].排灌机械工程学报,2015,33(12):1 033-1 037.
[14]刘厚林,丁剑,谈明高,等.叶轮出口宽度对离心泵噪声辐射影响的分析与试验[J].农业工程学报,2013,29(16):66-73.
[15]陈然伟,曾永忠,刘小兵.短叶片包角对离心泵水力性能影响的数值研究[J].中国农村水利水电,2015,(10):122-125.
[16]江伟,李国君,张新盛.离心泵叶片出口边倾斜角对压力脉动的影响[J].排灌机械工程学报,2013,31(5):369-372,378.