基于气液两相的导叶对液力透平内部流动规律的影响  

Effect of Guide Vanes on the Internal Flow Mechanism of Hydraulic Turbines under Gas-Liquid Two-Phase Conditions

作　　者：史广泰 彭家文 李金 薛志成 SHI Guang-tai;PENG Jia-wen;LI Jin;XUE Zhi-cheng(School of Energy and Power Engineering,Xihua University,Chengdu,China,610039;Xihua College,Xihua University,Chengdu,China,610039)

机构地区：[1]西华大学能源与动力工程学院,四川成都610039 [2]西华大学西华学院,四川成都610039

出　　处：《热能动力工程》2021年第3期48-54,共7页Journal of Engineering for Thermal Energy and Power

基　　金：中国博士后科学基金特别资助(2017T100077);中国博士后科学基金面上资助(2016M60090);西华大学重点科研基金(Z1510417);四川省教育厅科研项目(重点项目)(17ZA0366);西华大学流体及动力机械教育部重点实验室开放课题(szj2016-004)。

摘　　要：为了研究气液两相条件下导叶对液力透平内部流动特性的影响,现选取比转速为55.7的离心泵反转作为液力透平,并在液力透平叶轮进口添加一组负曲率导叶,设计出含导叶的水力模型,研究含气工况下导叶对液力透平性能的影响.研究发现:添加导叶前蜗壳和叶轮流道内压力分布和气相分布不均匀,且含气率越高均匀性越差,过流部件内流动较为紊乱,蜗壳和叶轮流道内出现了旋涡;添加导叶后,在较高含气率工况下叶轮流道内压力分布相对均匀且混合介质的流动情况得到改善,水力损失减少;添加导叶后透平最优效率点的值要高于未添加导叶的最优效率点的值,但随着含气率的提高,添加导叶的液力透平效率比未添加导叶的透平效率下降快.In order to study the effect of guide vanes on the internal flow mechanism of hydraulic turbines under gas-liquid two-phase conditions,a single-stage single-suction centrifugal pump with a specific speed of 55.7 is selected to invert as the hydraulic turbines.A hydraulic model with guide vanes was designed by adding a set of vanes at the inlet of the hydraulic turbine impeller,to study the effect of guide vanes on the external characteristics of hydraulic turbines and the flow field in each flow-through part under the gas-bearing condition,which then are compared with the external characteristics of hydraulic turbines without guide vanes,internal flow field,and hydraulic losses.The results show that the pressure distribution and gas distribution in the spiral casing before the addition of guide vanes are not uniform,and the higher the gas content is,the worse the homogeneity is.The internal flow is more turbulent and some vortexes have formed.With the addition of guide vanes,the pressure distribution in the impeller is also very uniform under higher gas-bearing conditions.The uneven distribution of gas and the flow of the mixed medium are all improved,the hydraulic loss is reduced,and the efficiency of the optimal efficiency point is improved.It is clearly higher than the efficiency of the optimal efficiency point of the hydraulic turbine without vane.However,with the increase of gas-bearing rate,the efficiency of hydraulic turbines with guide vanes decreases faster than that of hydraulic turbines without vanes.

关 键 词：液力透平 气液两相 内部流动 导叶 

分 类 号：TK264.9[动力工程及工程热物理—动力机械及工程]