空化模型热力学修正的核主泵空化研究

Analysis of Cavitation of Thermodynamic Cavitation Model for Reactor Coolant Pump

为研究核主泵的空化特性,基于ANSYS CFX软件,对现有Zwart-Gerber-Belamri空化模型进行热力学效应修正,在不同流量下采用修正前后的空化模型分别对模型核主泵进行数值计算,并将模拟值与试验值进行对比分析,验证了在核主泵空化发生时热力学效应修正的正确性。结果表明,未发生空化时,模型修正不具有明显影响,随着核主泵空化的加深,影响加大;模型泵空化性能的数值模拟预测与试验值趋势吻合,误差值在5.3%~9.6%之内,验证了空化数值模拟对核主泵工程应用中性能预测的可靠性;空化余量减小时,叶片低压区域从进口向出口扩张,随低压区域的扩张,汽泡填充整个流道,叶片载荷力降低,扬程下降。

To study the cavitation characteristics of the reactor coolant pump, the existing Zwart-Gerber-Belamri thermodynamic cavitation model has been improved by considering the heat transfer effect correction based on ANSYS CFX software, and the reactor coolant pump model is simulated before and after the improvement of cavitation model at different flow. Then, the comparative analysis of simulation and experimental values is verified that the thermodynamic effect improvement is correct when the reactor coolant pump cavitation occurs. The results show that when the cavitation does not occur, the improved model does not have an significant influence and the influence increases with the development of reactor coolant pump cavitation. Numerical simulation predicted trend of the model pump cavitation performance is consistent with the experimental values and the error value is in the 5.3% to 9.6%, which verified the numerical simulation of cavitation performance has a reliable prediction for engineering applications of reactor coolant pump. With the decreasing of NPSH, the area of low pressure expan from import to export on the impeller blade and bubble fills the entire impeller passage, also the head reduced.