共查询到15条相似文献,搜索用时 62 毫秒
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大型低扬程水泵采用渐扩出水流道,出水流道水力损失占泵扬程的15%~20%左右。为立式轴流泵设计制作了不同扩散角、无中隔板和有中隔板多种透明出水流道,采用五孔探针测定和丝线观测出水流道内流场,研究流场形成机理,分析流动规律,并与等圆出水管内流动比较。结果表明,由于后导叶出流环量、泵轴旋转诱导、出水弯管二次流和扩散的影响,出水流道内为复杂的螺旋流,断面轴向流速和周向流速分布不均匀、不对称,不均匀程度大于等圆出水管内流动,断面环量有向周边集中的趋势。成果对大型轴流泵装置出水部分的优化水力设计,提高泵装置效率有重大意义。 相似文献
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由于在型立式水泵出口导叶更换困难,本文对保留出口导叶,且在无冲击条件下分析研究了叶轮改型前一其出口速度和泵性能参数的变化关系,指出这种改造虽然经济划算,但技术上存在一定的局限性。 相似文献
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立式轴流泵常用于农业排灌、城市给排水、火电厂输送循环水等工程,具有大流量、低扬程、性能参数可变,以及适合低水位条件等优点。叶片是水泵的最重要部件,它直接影响和决定水泵的能量指标、汽蚀性能、水压脉动和泵组的运行振动。文中采用数控机床对某厂所需的轴流水泵叶片进行数控加工,并提出了相应的加工工序,以保证叶片各方面的技术指标可以达到或超过协议规定的各项技术要求。 相似文献
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后置导叶翼型斜流叶轮进口流场的实验研究 总被引:2,自引:0,他引:2
对不同来流条件的后置导叶翼型斜流风机,在不同叶顶间隙情况下的进口流场进行了实验研究。结果表明由进口调节门和预旋装置造成的周期性非均匀来流条件,是影响叶轮进口三维速度和压力损失分布的主要因素。尽可能保持较小的顶端间隙,以改善进口流场结构和降低压力损失有利。 相似文献
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轴流泵叶片外缘液流角β∞对轴流泵性能的影响 总被引:2,自引:0,他引:2
从理论上分析了轴流泵叶轮叶片外缘液流角β∞对轴流泵性能的影响,并从已有轴承泵水力模型资料找出比转速n2与tgβ∞.d的关系,为合理选择轴流泵的结构参数提供参考依据. 相似文献
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Qiu Baoyun Huang JiyanWater Conservancy College Yangzhou University Yangzhou ChinaYuan ShouqiFluid Mechanical EngineeringTechnique Center Jiangsu University Zhenjiang China 《机械工程学报(英文版)》2004,17(4):498-501
Characters of head of low head pump station and the pump shaft power are analyzed. Influence of each single factor on pump shaft power is expressed as change of specific shaft power (non-dimensional) and the probability density function is determined. Influences of multiple factors on pump shaft power are analyzed. Method of calculating none over-loaded probability of motor by integration by successive reductions is put forward and then relation between power spare coefficient and none over-loaded reliability of electric motor is established. Influences of all factors on pump shaft power being considered completely; power spare coefficients of motor are calculated in three kinds of heads (changing and unchanging), two kinds of dirty-out conditions. Electrical motor power spare coefficients should be chosen as 1.20-1.44, 1.11-1.19, 1.09-1.14 respectively when pump heads are 4, 7, 9.5 m. The results mean much to reasonable choose of electrical motors in large pump stations, increasing reliability of pump u 相似文献
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Analysis on the inner flow field of a centrifugal pump impeller with splitter blades is carried out by numerical simulation. Based on this analysis, the principle of increasing pump head and efficiency are discussed. New results are obtained from the analysis of turbulence kinetic energy and relative velocity distribution: Firstly, unreasonable length or deviation design of the splitter blades may cause great turbulent fluctuation in impeller channel, which has a great effect on the stability of impeller outlet flow; Secondly, it is found that the occurrence of flow separation can be decreased or delayed with splitter blades from the analysis of blade loading; Thirdly, the effect of splitter blades on reforming the structure of "jet-wake" is explained from the relative velocity distribution at different flow cross-sections, which shows the flow process in the impeller. The inner flow analysis verifies the results of performance tests results and the PIV test. 相似文献