摘要
为研究不同后泵腔轴向宽度下离心泵泵腔区域压力脉动的分布特性,以比转速为136的离心泵作为研究对象,在设计工况基于ANSYSCFX软件的SST湍流模型对6种不同后泵腔轴向宽度的离心泵外特性、内流场及压力脉动进行数值计算,最终得到离心泵定常压力及时域和频域分布规律。结果表明:随着后泵腔宽度的增大,扬程和轴功率均有不同程度的上升,效率曲线呈驼峰状,说明存在一个最佳宽度使流动损失最小;在设计工况下,同一泵腔宽度的0°和180°方向压力值较小,而90°及270°方向则相反,说明蜗壳型式对压力分布有一定约束作用;随着后泵腔轴向宽度的增加,泵腔中心截面距离叶轮盖板壁面越远,压力变化率越小,说明合适的泵腔宽度有利于改善泵腔内流动的均匀性;后泵腔压力脉动集中在0 Hz-2300 Hz内,主频均呈现为1倍叶频,压力脉动幅值随宽度增加呈先降后增趋势,即宽度b取18.9 mm时,后泵腔压力脉动幅值有效衰减,此时压力脉动稳定性明显改善。通过后泵腔轴向宽度的研究为改善泵腔性能及机组运行稳定性提供参考。
In order to study the distribution characteristics of the pressure pulsation in the pump centrifugal chamber area with different rear pump chamber axial widths,the centrifugal pump with a specific speed of 136 was used as the research object.Under the design conditions,the SST turbulence model based on ANSYS CFX software was used to calculate numerically to obtain the external characteristics,internal flow field and pressure pulsation of the centrifugal pump with six different kinds of the chamber axial width,and finally the distribution characteristics of constant pressure,time domain and frequency domain are derived.The results show that as the width of the rear pump chamber increases,the head and shaft power increase to varying degrees,and the efficiency curve is hump-shaped,indicating that there is an optimal width to minimize the flow loss;under design conditions with same pump chamber,the pressure values in the 0° and 180° directions of the width are smaller,while in the 90° and 270° directions are opposite,indicating that the volute type has a certain restriction on the pressure distribution;as the axial width of the rear pump chamber increases,the central section of the pump chamber is far away from the impeller back shroud,and the smaller the pressure change rate is,indicating that a suitable pump chamber axial width is beneficial to improve the uniformity of the flow in the pump chamber area.The pressure pulsation in the rear pump chamber is concentrated in 0 Hz-2 300 Hz,and the main frequency presents double blade frequency,while with the increase of rear chamber width,firstly the amplitude of pressure pulsation decreases and then increases,that is,when the width b is 18.9 mm,the pressure pulsation amplitude of the rear pump chamber is effectively attenuated,and the pressure pulsation stability is obviously improved at this time.The study of the axial width of the rear pump chamber provides a reference for improving the performance of the pump chamber and the stability of the unit.
作者
梁武科
朱金瑞
董玮
何庆南
艾改改
刘云琦
Wu-ke Liang;Jin-rui Zhu;Wei Dong;Qing-nan He;Gai-gai Ai;Yun-qi Liu(Institute of Water Resources and Hydro-electric Engineering,Xi’an University of Technology,Xi’an 710048,China;College of Water Conservancy and Civil Engineering,Northwest A&F University,Yangling 712100,China)
出处
《水动力学研究与进展（A辑）》
CSCD
北大核心
2022年第2期234-243,共10页
Chinese Journal of Hydrodynamics
基金
国家自然科学基金资助项目(52009114)
陕西省水利科技计划项目经费资助(2019slkj-15)
中国博士后科学基金面上资助项目(2021M692660)
水力发电设备国家重点实验室开放课题(SKLHE-ORF-202103)。
关键词
离心泵
后泵腔
轴向宽度
压力脉动
数值分析
Centrifugal pump
Rear chamber
Axial width
Pressure pulsation
Numerical analysis
