苗森春,杨军虎,王晓晖,史凤霞,史广泰
MIAO Sen-chun,YANG Jun-hu,WANG Xiao-hui,SHI Feng-xia,SHI Guang-tai

• 1:兰州理工大学
• 2:甘肃省流体机械及系统重点实验室
• 3:流体及动力机械教育部重点实验室(西华大学)

摘要(Abstract)：

叶片数是泵作液力透平时的主要几何参数之一,为了明确叶片数对泵作液力透平时的性能影响,基于N-S方程和标准k-ε湍流模型,采用SIMPLE算法,应用FLUENT流场模拟软件对不同叶片数下的泵用作液力透平时进行了数值计算,得到了不同叶片数下液力透平的外特性曲线并分析内部流动规律。结果表明:对于低比转速离心泵作液力透平,随着叶片数的增加,流量从最高效率点向小流量偏移时效率下降的梯度增大,而从最高效率点向大流量偏移时效率呈现先增大后减小的变化趋势,另外液力透平的最高效率点随叶片数增加向小流量偏移;压头随叶片数的变化在小流量变化相对较小,而在大流量工况时,随着叶片数的增加呈现逐渐增大的趋势。内流场分析表明,随着叶片数的逐渐增加,透平叶轮中漩涡区域逐渐减小,叶轮内部的流动有很大的改善。但结合外特性分析发现,叶片数过多的增加反而不利于透平性能的提升,因此,对于具体参数组合的液力透平,存在着最佳叶片数使得泵作液力透平的性能达到最优。
The number of blades is one of the main geometrical parameters of the pump for the hydraulic turbine. In order to make clear the influence of the number of blades on the performance of the pump for the hydraulic turbine,based on N-S equation and standard k-ε turbulence model,using SIMPLE algorithm,the flow field simulation software Fluent was applied to the numerical calculation of the pump for different blade numbers. The external characteristic curves of the hydraulic turbine with different blade numbers were obtained and the internal flow pattern was analyzed. Results show that with the gradual increase of the number of blades,the flow rate decreases from the maximum efficiency point to the small flow rate,and the efficiency is increased at first and then decreases. In addition,the maximum efficiency point of the hydraulic turbine is offset to the small flow rate. With the change of the number of blades,the pressure head is relatively small,but the increase of the number of blades increases with the increase of the number of the large flow condition. Internal flow field analysis showed that with the gradual increase of the number of blades,the vortex area of the turbine impeller is gradually reduced,and the flow inside the impeller is greatly improved. However,the increase of the number of blades increases the friction loss on the surface of the blade. Therefore,for the specific parameters of the combination of hydraulic turbine,there is the best number of blades makes the performance of the pump for the hydraulic turbine to achieve the best.

关键词(KeyWords)： 叶片数;泵作液力透平;数值计算;漩涡;摩擦损失
blade number;pump as turbine;numerical calculation;vortex;friction loss

Abstract:

Keywords:

基金项目(Foundation): 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)

作者(Author): 苗森春,杨军虎,王晓晖,史凤霞,史广泰
MIAO Sen-chun,YANG Jun-hu,WANG Xiao-hui,SHI Feng-xia,SHI Guang-tai

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