基于流量分段和对应模型的超临界锅炉给水泵性能预测

Performance Prediction of a Supercritical Boiler Feed Water Pump Based on Subsection Characteristics and Turbulence Models

以超临界汽动锅炉给水泵CHTZ6/6为研究对象,建立多级该泵内部流道的三维实体模型.应用CFD技术,借助于大型并行计算机进行多工况点的定常数值模拟.结果表明:在额定工况点和最大流量工况点采用RNGκ-ω模型的数值结果与实验数据吻合良好,而在最小流量工况点模拟的误差较大.对比额定工况和最低流量工况,第三级流道中心截面小流量工况时流道内存在大量的脱落涡和旋转失速团,改用SSTκ-ω模型来分段计算小流量工况,发现低于0.8 qv,n时,SSTκ-ω模型能普遍提高模拟效率减少计算误差,从而得到了与该泵实际运行更为接近的外特性曲线.

With the type CHTZ6/6 supercritieal boiler feed water pump as the study model,the 3D model of internal flow passage of the multistage pump was established. Based on the CFD technology and the large-scale parallel computer, the steady numerical simulation of multi operating points were conducted. It was shown that the simulated performance parameters of RNG mode obtained at the rated point and at the maximum flow point closely coincided with the experimental ones while the simulation error at the mini mum flow point was large. A contrast between rated conditions and low flow condition showed that there were lots of shedding vortexes and rotating stall groups in the flow passage when the third channel center section was under the low flow condition. And then the SST model was used to piecewise calculate the low flow conditions, and when the SST simulation model was below 0.8 q the efficiency of the simulations was increased and the numerical error was decreased. Thus,the external characteristic curve that is closer to the real per{ormance of the curve was obtained