JP75型卷盘喷灌机用水涡轮能耗贡献率分析

为对JP75水涡轮各过流部件展开能耗贡献率研究,探究水涡轮性能,利用水涡轮试验台对JP75水涡轮在不同转速下进行外特性试验,并确定水涡轮最优转速(250 r/min);采用CERO和STAR-CCM+前处理对水涡轮全流道内流场进行三维建模、多面体网格划分以及数值计算;计算得到水涡轮在固定转速下的外特性曲线,与试验结果的平均误差为3.28%.计算不同工况下流场内部各处能耗,发现叶轮与进出水管道连接处平均总能耗达到52.18%,其中叶轮与进水管道连接处能耗贡献率达到44.80%,分析云图发现此处压力梯度较大,分布不均匀,叶片工作面涡旋现象明显,说明此处能量耗散现象最为严重,在此基础上,对JP75水涡轮采取优化设计,优化后其效率得到显著提升,水头有明显降低且输出功率得到保证.

Energy consumption analysis of hydraulic turbine of JP75 hose reel irrigator

For study on energy consumption of various hydraulic components of the hydraulic turbine of JP75 hose reel irrigator, the external characteristic of the turbine is tested and the flow field is numerically simulated based on a commercial software STAR-CCM+. According to an analysis of pressure and velocity distributions in the turbine, the energy consumption in the connection between the impeller and the inlet pipe is 44.80%, while the whole consumption of the connection is 52.18%. It is also shown that a serious energy consumption are associated with a high pressure gradient and appearance of vortex. Based on this, the original hydraulic turbine design is optimized. As a result, the turbine total efficiency is significantly improved, the total head is reduced obviously and the nominal output power is guaranteed, eventually the goal of optimization has been achieved.