作　　者： (李琪飞）; (刘超）; (王源凯）;

机构地区： 兰州理工大学能源与动力工程学院,甘肃兰州730050 甘肃省流体机械及系统重点实验室,甘肃兰州730050

出　　处： 《排灌机械工程学报》 2017年第8期680-684,共5页

摘　　要： 为研究部分负荷工况下水泵水轮机空化系数改变对内流特性的影响,采用RNG k-ε湍流模型和Schnerr-Sauer空化模型,对某抽水蓄能电站模型机进行了全流道非定常空化流动数值计算,并分析了机组处于不同空化阶段时的水力性能及内流状态.研究结果显示:逐步发展的空化会引起水力效率降低和轴向力显著增大;部分载荷时,空化产生的涡带起源于泄水锥处,呈螺旋形向下游低速运动;随着空化系数的减小,涡带形态逐渐由细变粗,低压区覆盖范围向外扩展,沿半径方向的速度变化更加急剧.在空化涡带旋进的过程中,流道内出现了严重的二次回流,主流沿着锥管壁面向下游推进,引发壁面的冲撞而引起激烈的振动,这种结果对机组的稳定高效运行非常不利. To study the influence of cavitation coefficients of pump turbine on the inner flow characteristics under the partial load condition,the unsteady numerical simulation was carried out by using the RNG k-ε turbulence model and Schnerr-Sauer cavitation model,based on the model pump turbine in a pumped storage power station. The hydraulic performance and inner flow state of the unit at different cavitation stages were analyzed. The results show that the occurrence and hydraulic efficiency decreased after cavitation developed and the axial force increased significantly. Under the partial load condition,cavitation vortex strip originated in the runner cone and motioned slowly in spiral type toward to the downstream. With the decrease of the cavitation coefficients,vortex strip gradually changed from fine to coarse. The coverage of the low-pressure area extended outward and the velocity changed more rapidly in the radial direction. There was a serious second backflow in the movement process ofthe cavitation vortex strip. The main stream advanced on the downstream along the cone tube wall. This is extremely easy to hit the wall and causes the strong hydraulic vibration,which adversely affects the operation security and stability of the unit.

关 键 词： 水泵水轮机 部分负荷 空化性能 内部流动 数值模拟