Study on the Influence of Eccentricity Ratio on the Sealing Excitation Force Caused by Impeller Wear-ring of a Reactor Coolant Pump
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摘要: 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。Abstract: 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-ε turbulence 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 wear-ring 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.
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表 1 模型泵额定参数
Table 1. Rated Parameters of Model Pump
额定参数 数值 流量(Q)/(m3·h−1) 3085 扬程(H)/m 25.7 转速/(r·min−1) 1485 效率/% 82.5 表 2 口环密封主要几何参数
Table 2. Main Geometric Parameters of Wear-Ring Sealing
参数 理论值/mm 口环密封直径(D) 394 口环密封长度(l) 100 口环密封间隙(h) 0.4 -
[1] ZHANG M, WANG X F, XU S L, et al. Leakage characteristic of helical groove seal designed in reactor coolant pump[J]. International Journal of Rotating Machinery, 2012(2012): 619459. [2] 胡文盛,洪均. 反应堆压力容器密封环国产化替代研究[J]. 核动力工程,2020, 41(6): 172-176. [3] 吴大转,许斌杰,武鹏,等. 多级离心泵内部间隙流动与泄漏损失[J]. 浙江大学学报: 工学版,2011, 45(8): 1393-1398. [4] 牟介刚,代东顺,谷云庆,等. 叶轮口环结构对离心泵性能及流场的影响[J]. 中南大学学报: 自然科学版,2017, 48(6): 1522-1529. [5] 崔哲,赵存生,魏云毅. 叶轮口环间隙对离心泵性能和振动影响的试验研究[J]. 流体机械,2020, 48(1): 1-6. doi: 10.3969/j.issn.1005-0329.2020.01.001 [6] SALVADORI S, MARINI A, MARTELLI F. Methodology for the residual axial thrust evaluation in multistage centrifugal pumps[J]. Engineering Applications of Computational Fluid Mechanics, 2012, 6(2): 271-284. doi: 10.1080/19942060.2012.11015420 [7] WILL B C, BENRA F K, DOHMEN H J. Investigation of the flow in the impeller side clearances of a centrifugal pump with volute casing[J]. Journal of Thermal Science, 2012, 21(3): 197-208. doi: 10.1007/s11630-012-0536-3 [8] BLACK H F. Effects of hydraulic forces in annular pressure seals on the vibrations of centrifugal pump rotors[J]. Journal of Mechanical Engineering Science, 1969, 11(2): 206-213. doi: 10.1243/JMES_JOUR_1969_011_025_02 [9] 程效锐,王晓全,陈红杏. 高速离心泵口环密封流体激振力特性研究[J]. 水动力学研究与进展A辑,2019, 34(6): 740-748. [10] 任朝晖,魏杰涛,李永超,等. 螺旋密封的密封能力及参数优化[J]. 东北大学学报: 自然科学版,2016, 37(12): 1755-1758. [11] WATSON C, WOOD H. Optimising a helical groove seal using computational fluid dynamics[J]. Sealing Technology, 2017, 2017(11): 5-9. doi: 10.1016/S1350-4789(18)30012-6 [12] 陈汇龙,吴远征,孙冬冬,等. 泵口环圆柱面螺旋槽造型的流体动力特性[J]. 江苏大学学报: 自然科学版,2019, 40(2): 145-151. [13] 杨从新,刘满,王秀勇,等. 动静叶栅间隙对钠冷快堆二回路泵压力脉动特性的影响[J]. 核动力工程,2020, 41(1): 127-133. [14] 陈兴江,彭放,丛国辉,等. 百万千瓦级核电站轴封型主泵整机集成试验验证优化方案研究[J]. 核动力工程,2020, 41(1): 113-116. [15] 冯晓东,马宇,宋奎龙,等. 反应堆冷却剂泵动压机械密封的工程开发与应用[J]. 核动力工程,2019, 40(3): 142-145. [16] 高波,王震,杨丽,等. 不同口环间隙离心泵性能及水力激励特性分析及试验[J]. 农业工程学报,2016, 32(7): 79-85. doi: 10.11975/j.issn.1002-6819.2016.07.011