偏心率对核主泵叶轮口环密封激励力的影响研究

Study on the Influence of Eccentricity Ratio on the Sealing Excitation Force Caused by Impeller Wear-ring of a Reactor Coolant Pump

为探究转子偏心率对核主泵转子密封激励力的影响,基于雷诺时均N-S方程和RNG k-ε湍流模型,选取平面密封、迷宫密封和螺旋密封3种口环结构方案,对核主泵口环间隙内部流动进行数值计算,得到口环间隙区域压力、泄漏量及其密封激励力的分布规律。结果表明,模型泵性能预测值和试验值较为吻合,扬程最大误差为4.78%。在转子无偏心时,相对于平面密封,采用螺旋密封方案时口环泄漏量显著降低93.1%,而密封激励力增加63%。偏心率为10%时,口环压力分布沿周向较为均匀;当偏心率为30%时,周向靠近偏心位置处,口环间隙内部产生带状压力突升区,相对于无偏心方案,平面密封的泄漏量显著降低43.6%,而密封激励力增大4.4倍,迷宫密封和螺旋密封方案可显著降低转子偏心产生的密封激励力,其中迷宫密封可显著降低55%;偏心率为50%时,口环间隙内部带状压力突升区域偏向高压侧。本数值预测方法为揭示偏心转子对核主泵口环密封激励力的影响提供理论依据。

In order to explore the influence of rotor eccentricity ratio on the sealing excitation force caused by rotor of the reactor coolant pump,based on the Reynolds-averaged Navier-Stokes equations and RNG k-εturbulence model,3 types of wear-ring sealing schemes of plane seal,labyrinth seal and spiral seal are selected to numerically calculate the internal flow inside the wearring clearance of the reactor coolant pump,and the distribution laws of pressure,leakage and sealing excitation force inside the clearance of wear-ring are obtained.The results show the predicted performance of the model pump is in good agreement with the experimental value,and the maximum error of head is 4.78%.When the rotor has no eccentricity,compared with the plane seal,the leakage of the wear-ring by the spiral seal scheme can be significantly reduced by 93.1%,and the sealing excitation force can increase by 63%.When the eccentricity ratio is 10%,the pressure distribution of the wear-ring is more uniform along the circumferential direction;When the eccentricity ratio is 30%,there is a band pressure sudden rise zone in the clearance of wear-ring near the eccentric position in the circumferential direction.Compared with the non-eccentric scheme,the leakage of the plane seal is significantly reduced by 43.6%,and the sealing excitation force is increased by 4.4 times,labyrinth seal and spiral seal can significantly reduce the sealing excitation force caused by eccentric rotor,and labyrinth seal can significantly reduce by 55%;When the eccentricity ratio is 50%,the band pressure sudden rise zone within the wear-ring clearance tends to the high-pressure side;The numerical prediction method provides a theoretical basis for revealing the influencing factors of eccentric rotor on the sealing excitation force of the reactor coolant pump.