大型凝结水泵空化流动数值计算

Numerical calculation of cavitating flow in large-sized condensate pumps

针对10LDTNB-5PJ型凝结水泵首级叶轮在实际运行中空蚀现象比较严重的问题,以时均N-S方程和标准k-ω模型为基础,应用CFD软件对该叶轮在设计工况和最优工况下的运行情况进行空化模拟计算.得到两种工况下叶轮流道内空蚀发生的部位和叶轮内部液相和气相的体积分数,并对叶轮的空化性能进行预测.结果表明,两种运行工况下叶片进口靠近吸力面处均有空蚀现象出现,且最优工况的空化程度比设计工况下的空化程度严重,与泵的实际运行情况一致.验证了计算模型和方法的正确性和实用性.

Aimed at the serious cavitation problem in the first-stage impeller of 10LDTNB-5PJ type condensate pump, the cavitating flow for this impeller operating in optimum and design conditions was conducted with CFD software on the basis of time-averaged N-S equations and the standard k-to turbulence model. Cavitations occurred and the volumetric fractions of liquid and gaseous-phase in the impeller in dif- ferent operations were obtained and cavitation was predicted. The results showed that cavitation took place at the blade inlet near its suction side in both conditions and cavitation for optimum condition was more serious than that for the design condition, which accorded with actual operation. So that the correctness and practicability of the calculation model and method are verified.