摘要
意大利某水电站更换转轮后,发现当其在高水头、大开度且以双喷嘴方式运行时,水轮机效率随着喷针开度的增加(尚未开到额定开度值)却意外下降了5%。针对该问题,运用了CFD软件对包括转轮、喷嘴、机壳、机盖等在内的水轮机内部流场进行了非定常气水两相流数值模拟,分析确定了水轮机效率下降的原因。随后提出了对该水轮机增设挡水板的改进方案。计算结果表明,该改进方案阻止了水流再次返回至转动区域,水轮机效率下降问题得到了解决。
After replacing the runner of Pelton turbine in an Italian hydropower station with Chinese production,the efficiency of turbine decreases by 5% with the increasing of needle opening which still below rated opening when the turbine operates at high water head,big opening and double nozzle mode during on-site performance acceptance test.For solving this problem,the CFD software is used to simulate the internal flow field of unsteady gas-water two-phase flow of turbine including runner,nozzle,casing and machine cover,and the reasons of efficiency decrease is analyzed.The improvement scheme of adding baffle plate is proposed.The simulation results show that the improvement can prevent water flowing back to rotating parts and the efficiency decrease is resolved.
出处
《水力发电》
北大核心
2016年第6期49-52,共4页
Water Power
基金
国家自然科学基金资助项目(51379179)
河南省高等学校青年骨干教师资助项目(2013GGJS-197)
关键词
水力机械
冲击式水轮机
喷嘴
性能试验
数值模拟
hydraulic machinery
Pelton turbine
nozzle
performance test
numerical simulation
