600MW超临界锅炉给水泵叶轮出口宽度优化设计

Optimization of Impeller Outlet Width for 600 MW Supercritical Boiler Feed Pump

增加叶轮出口宽度是降低离心泵关断点扬程的典型方法。针对600 MW超临界锅炉给水泵关断点扬程过高问题,分别提出4种增加叶轮出口宽度的方式对其进行改型设计。对其中1种改型方案通过试验方法研究,其余3种改型方案采用CFD方法研究。结果表明:采用移动前盖板出口的方法降低关断点扬程的效果最佳,其水力性能参数优于其余3种方法,运行流量为1 250 m3/h时,相比于平行移动前盖板方法效率增加1.9%;叶轮出口宽度变化比与扬程变化比在一定范围内满足二次多项式回归关系。在此基础上,拟合出二次多项式方程。

There is a typical method for hydraulic performance of centrifugal pump, which is called width increasing of impeller outlet. Four methods of increasing impeller outlet width were put forward aiming at 600 MW supercritical pressure boiler feed pump cut- off head over high. Test method was introduced to investigate one of four increasing impeller outlet methods, the others were used CFD to analyze. Results indicate that the method of moving frond shroud outlet has the best effect on decreasing pump cut-off head and hy- draulic parameters. Compared with ＂moving frond shroud＂, using ＂moving frond shroud outlet＂, efficiency is enhanced by 1.9%. The relationship between width ratio and head ratio could be expressed by quadratic polynomial regression, then the quadratic polynomial equation was fit.